Wnt/β-Catenin Signaling and Resistance to Immune Checkpoint Inhibitors: From Non-Small-Cell Lung Cancer to Other Cancers

Lung cancer is the leading cause of cancer-related deaths worldwide. The standard of care for advanced non-small-cell lung cancer (NSCLC) without driver-gene mutations is a combination of an anti-PD-1/PD-L1 antibody and chemotherapy, or an anti-PD-1/PD-L1 antibody and an anti-CTLA-4 antibody with or without chemotherapy. Although there were fewer cases of disease progression in the early stages of combination treatment than with anti-PD-1/PD-L1 antibodies alone, only approximately half of the patients had a long-term response. Therefore, it is necessary to elucidate the mechanisms of resistance to immune checkpoint inhibitors. Recent reports of such mechanisms include reduced cancer-cell immunogenicity, loss of major histocompatibility complex, dysfunctional tumor-intrinsic interferon-γ signaling, and oncogenic signaling leading to immunoediting. Among these, the Wnt/β-catenin pathway is a notable potential mechanism of immune escape and resistance to immune checkpoint inhibitors. In this review, we will summarize findings on these resistance mechanisms in NSCLC and other cancers, focusing on Wnt/β-catenin signaling. First, we will review the molecular biology of Wnt/β-catenin signaling, then discuss how it can induce immunoediting and resistance to immune checkpoint inhibitors. We will also describe other various mechanisms of immune-checkpoint-inhibitor resistance. Finally, we will propose therapeutic approaches to overcome these mechanisms.

the diagnostic value of left-anterior-descending artery velocity assessed by transthoracic Doppler echocardiography for microvascular dysfunction in stenotic left-anterior-descending artery

Background

Index of microcirculatory resistance (IMR) has been used as a clinical measure of microvascular function. Transthoracic Doppler echocardiography (TDE) can provide information on the functional status of coronary artery circulation. This study aims to assess the diagnostic value of left-anterior-descending artery (LAD) flow velocity by TDE for microvascular dysfunction.

Methods

Consecutive patients who were scheduled for elective percutaneous coronary intervention (PCI) for LAD lesions were prospectively enrolled in the single tertiary-care center between April 2020 and July 2021. Pre-PCI LAD diastolic peak velocity (DPV) by TDE at rest and hyperemia were measured. By invasive coronary angiography, quantitative coronary angiography and invasive wire-based physiological indices including fractional flow reserve (FFR) and index of microcirculatory resistance (IMR) were measured.

Results

A total of 104 patients were studied. Median FFR and IMR values were 0.70 (0.60–0.74) and 20.68 (14.92–31.69), respectively. No significant relationship was observed between FFR and IMR. The prevalence of microvascular dysfunction defined as IMR≥25 was 39.4%. Basal DPV was 25 (20–33) cm/sec, and hyperemic DPV was 51 (41–67) cm/sec. In lesions with IMR≥25, reference diameter (RD) was significantly greater [2.63 (2.22–3.19) mm vs 2.39 (2.09–2.66) mm, p=0.019], basal DPV was lower [26 (18–29) cm/sec vs 29 (22–37) cm/sec, p=0.022)] and hyperemic DPV was lower [49 (19–54) cm/sec vs 56 (42–70) cm/sec, p=0.023] compared to lesions with IMR<25. ROC analysis showed basal DPV and RD are significant predictors of IMR≥25 [basal DPV: AUC 0.633 (0.525–0.742), best cutoff 29cm/sec RD: AUC 0.636 (0.523–0.750), best cutoff 2.84mm]. Multivariable logistic regression analysis showed basal DPV<29cm/sec and RD>2.84mm are independent predictors for IMR≥25 [Odds ratio: 3.08 (1.22–7.78), p=0.017; odds ratio 4.40 (1.55–12.50), p=0.005].

Conclusion

Basal DPV by non-invasive pre-PCI TDE and reference diameter can predict lesions with coexisting microvascular dysfunction in LAD territory with functionally significant lesions without the need of vasodilator-induced hyperemia and a wire-based invasive physiological measurement.

Funding Acknowledgement

Type of funding sources: None.

Prognostic implications of unrecognized myocardial infarction before elective percutaneous coronary intervention

Background

A non-negligible proportion of myocardial infarction (MI) is not clinically recognized and unrecognized myocardial infarction (UMI) is associated with adverse outcomes.

Purpose

To determine the prevalence and prognostic significance of UMI by delayed-enhancement cardiac magnetic resonance (DE-CMR) before elective percutaneous coronary intervention (PCI).

Methods

In this prospective, single-center study, 236 patients with stable coronary artery disease undergoing elective and uncomplicated PCI were studied. All patients underwent DE-CMR before PCI. The prevalence of UMI was evaluated and the association of clinical and CMR-derived variables with primary MACE, defined as cardiovascular death, nonfatal MI, hospitalization for heart failure, unplanned late revascularization, and ischemic stroke was investigated.

Results

In the final analysis of 213 patients, 63 patients (29.6%) showed UMI. Target territory UMI was observed in 38 (17.8% of total, 60.3% of patients with UMI). UMI was significantly associated with sex, diabetes mellitus, left ventricular ejection fraction, SYNTAX score and fractional flow reserve in target vessels. During follow-up periods (median, 23 months), MACE was observed in 17 (27.0%) of patients with UMI, and 17 (11.3%) without (P=0.001). In a multivariable model, UMI (hazard ratio [HR] 2.18, 95% confidential interval, 1.10–4.33, P=0.001) remained as an independent predictor of MACE. Kaplan–Meier analysis indicated that the presence of UMI was significantly associated with higher incidence of MACE.

Conclusions

The prevalence of UMI in patients undergoing elective PCI was 29.6%. UMI was independently associated with an increased risk of MACE after successful PCI. Given the non-negligible prevalence and potential clinical significance of UMI, clinical studies comparing PCI and guideline directed medical therapy (GDMT) versus GDMT only strategy might have to take the presence of UMI into consideration.

Funding Acknowledgement

Type of funding sources: None.

Prognostic implication of unrecognized myocardial infarction in patients with non-ST-segment-elevation acute coronary syndrome

Background

Prognostic value of unrecognized non-infarct-related territory (non-IR) myocardial infarction (UMI) in patients with non-ST-segment-elevation acute coronary syndrome (NSTE-ACS) remains to be elucidated.

Purpose

This study sought to evaluate the prevalence of non-IR UMI and its prognostic value in patients with first NSTE-ACS presentation.

Methods

This retrospective single-center analysis was conducted in patients with NSTE-ACS without prior history of coronary artery disease, who underwent uncomplicated urgent percutaneous coronary intervention (PCI) within 48 hours of admission between August 2014 and January 2018. All patients underwent postprocedural cardiac magnetic resonance imaging (CMR) within 30 days after PCI. Non-IR UMI was defined as the presence of non-IR delayed gadolinium enhancement with an ischemic distribution pattern. We investigated the association of non-IR UMI, other CMR findings and baseline clinical characteristics with major adverse cardiac events (MACE), defined as all-cause death, non-fatal myocardial infarction, ischemic stroke, late revascularization and hospitalization for congestive heart failure.

Results

A total of 168 NSTE-ACS patients were included (124 males (73.8%); 66±11 years). Non-IR UMI was detected in 28 patients (16.7%). During a median follow-up of 32 months (15–58), MACE occurred in 10 (35.7%) patients with non-IR UMI, and 20 (14.3%) patients without (P=0.013). Patients with MACE showed higher frequency of non-IR UMI in RCA territory and multi vessel disease, higher level of NT-proBNP at admission, higher Genisini score, and greater extent of UMI. Cox's proportional hazards analysis showed that the presence of non-IR UMI was an independent predictor of MACE (HR 2.34, 95% CI 1.02–5.37, P=0.045), after adjusting confounding factors, such as multi vessel disease and serum levels of NT-proBNP at admission. The discriminant efficacy (IDI and NRI) of predicting MACE was significantly improved when the presence of non-IR UMI added to the reference clinical risk model. Kaplan-Meier analysis revealed that patients with non-IR UMI were significantly associated with poor prognosis. (Figure 1).

Conclusions

In patients with NSTE-ACS undergoing urgent PCI, the prevalence of non-IR UMI was 16.7%. Non-IR UMI provided prognostic information independent of conventional risk factors.

Funding Acknowledgement

Type of funding sources: None.

Identification of coronary plaque rupture or erosion by preprocedural computed tomography angiography in patients with non-st-segment elevation acute coronary syndrome

Background

The frequent pathological cause of acute coronary thrombosis is plaque rupture or erosion. A previous CT angiographic study failed to discriminate OCT-defined intact fibrous cap culprit lesions (IFC lesions) from those with ruptured fibrous cap (RFC group) in patients with acute coronary syndrome (ACS) and chronic coronary syndrome.

Objectives

This study aimed to evaluate the diagnostic efficacy of preprocedural coronary CT imaging to identify optical coherence tomography (OCT)-defined plaque rupture or erosion at culprit lesions in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS).

Methods

Consecutive patients with suspected NSTE-ACS who underwent preprocedural non-contrast CT and CT angiography (CCTA) were studied. Patients with at least one lesion with more than 50% stenosis at the proximal segment on CCTA were subsequently assessed by invasive coronary angiography and OCT. ALL CT and OCT examination were performed within 24 hours from presentation. The diagnosis of intact fibrous cap or ruptured fibrous cap was made by OCT for the angiographically most severely stenosed lesion. Cases of ambiguous OCT diagnosis such as massive thrombosis or calcified nodule precluding the fibrous cap assessment were excluded from the final analysis.

Results

In the final analysis of 176 patients, OCT identified 87 RFC plaques and 89 IFC plaques for the culprit lesions, respectively. In IFC group, lower prevalence of diabetes mellitus (24.7% vs. 41.4%, P=0.025) and lower peak cardiac marker elevation (CPK, 159 vs. 272 U/L, P<0.001) were observed. On CT, the prevalence of low attenuation plaque, positive remodeling, napkin ring sign, spotty calcification, calcium score (CAC), and culprit vessel pericoronary adipose tissue attenuation (FAI) were all significantly low in IFC group. Multivariate regression analysis to predict IFC at culprit lesions revealed that the absence of low attenuation plaque, the absence of napkin ring sign, zero CAC, and low FAI were independent predictors of IFC. When stratified by the number of these 4 CT factors, the presence of IFC were stratified as 0%, 23.6%, 50%, 77.8%, and 100% (P<0.001), respectively. Adding non-contrast CT factor of zero CAC to the reference model including age, sex, DM, EF, low attenuation plaque, napkin ring sign, and FAI, can increase the incremental discriminatory and reclassification performance for the prediction of IFC (C-statistic 0.828 NRI: 0.37, 95% CI: 0.095–0.646, P=0.008 and IDI: 0.042, 95% CI: 0.012–0.071, P=0.005).

Conclusions

Preprocedural comprehensive CT imaging including CAC and pericoronary adipose tissue inflammation could identify IFC or RFC culprit lesions defined by OCT. Further studies are needed to confirm our preliminary results and if CT imaging in NSTE-ACS provides prognostic information or specific therapeutic approach such as conservative therapy or non-stenting strategy before invasive angiography.

Funding Acknowledgement

Type of funding sources: None.

Diagnostic value of computed tomography myocardial perfusion to detect coexisting microvascular dysfunction in patients with obstructive epicardial coronary disease

Background

The usefulness of computed tomography myocardial perfusion (CTP) to assess hemodynamically significant epicardial coronary artery lesions has been previously reported. However, the diagnostic value of quantitative evaluation of absolute coronary flow by CTP to detect microvascular dysfunction remains unknown.

Purpose

The aim of study is to assess the diagnostic value of CTP to evaluate coronary microvascular dysfunction (CMD) in patients with significant epicardial coronary stenosis, and to analyze the predicting factors for lesions with CMD.

Methods

Sixty-eight chronic coronary syndrome patients with de novo single functionally significant stenosis (Fractional flow reserve [FFR] <0.80) were investigated. CMD was defined by the index of microcirculatory resistance (IMR) ≥25. Clinical characteristics and CTP findings were compared between the two groups with and without CMD (CMD, n=29, non-CMD, n=39, respectively). The computed tomography angiography (CCTA) assessment included CTP findings and quantitative and qualitative assessment of plaques.

Results

In wire-based analysis, FFR, coronary flow reserve (CFRwire) and IMR were 0.68 (0.59–0.74), 1.71 (1.24–2.88), and 22.6 (15.1–34.5), respectively.

In CTP analysis, culprit territory regional absolute myocardial blood flow (MBF) at rest (rest-MBF) and hyperemia (hyperemic-MBF) were evaluated semi-automatically. CTP-derived CFR (CFRCTP) was calculated as hyperemic-MBF divided by rest-MBF. Rest and hyperemic-MBF and CFRCTP were 0.83 (0.64–1.03) ml/min/g, 2.14 (1.30–2.92) ml/min/g, and 2.19 (1.44–3.37).

In the lesions with CMD, hyperemic-MBF was significantly lower than those without CMD (1.68 [0.84–2.44] vs 2.31 [1.67–3.34] ml/min/g, p=0.015) and the prevalence of CFRCTP<2.0 was higher in the lesions with CMD than those without CMD (62.1% vs 28.2%, p=0.007).

CCTA analysis showed that fibrofatty and necrotic core component (FFNC) volume was greater in the lesions with CMD than in the lesions without CMD (31.8 [19.0–48.9] vs 25.1 [17.2–32.1] mm3, p=0.045). The multivariable logistic regression analysis, hyperemic-MBF and FFNC volume were independent predictors for lesions with CMD (Odds ratio [OR] 0.583 [0.355–0.958], p=0.033 and OR 1.040 [1.010–1.070], p=0.018).

Conclusion

Quantitative assessment of absolute coronary flow by CTP and comprehensive plaque analysis by CCTA may help detect coexisting subtended microvascular dysfunction in patients with functionally significant epicardial coronary lesions. Further studies are needed to elucidate the clinical significance of coexisting CMD in CCS patients.

Funding Acknowledgement

Type of funding sources: None.

Multimodality coronary imaging to predict non-culprit territory unrecognized myocardial infarction assessed by cardiac magnetic resonance in non-ST-elevation acute coronary syndrome

Objectives

This study sought to assess the predictors of coherence tomography (OCT) and coronary computed tomography angiographic (CCTA) findings for non-infarct-related (non-IR) territory unrecognized myocardial infarction (UMI) in patients with first non-ST-elevation acute coronary syndrome (NSTE-ACS) presentation.

Background

UMI detected by cardiac magnetic resonance (CMR) is associated with adverse outcomes in patients with both acute coronary syndrome and chronic coronary syndrome. However, the association between the presence of UMI and findings of multimodality coronary imaging remains unknown.

Methods

We investigated 69 patients with a first clinical episode of NSTE-ACS, who underwent pre-PCI 320-slice CCTA, uncomplicated urgent percutaneous coronary intervention (PCI) with OCT assessment within 48 hours of admission, and post-PCI CMR. UMI was assessed on late gadolinium enhancement (LGE-CMR) by identifying regions of hyperenhancement with an ischemic distribution pattern in non-IR territories (non-IR UMI).

Results

Non-IR UMI was detected in 11 patients (15.9%). ROC analysis revealed the optimal cut-off value of PCATA in culprit vessel for predicting the presence of non-IR UMI were −71.3. Lower ejection fraction, higher Gensini score, high pericoronary inflammation (>−71.3), OCT-defined culprit lesion plaque rupture (OCT-PR), and OCT-defined culprit lesion cholesterol crystal (OCT-CC) were significantly associated with the presence of non-IR UMI (Figure 1A). OCT findings are shown in Figure 1B. Patients with non-IR UMI had a higher prevalence of OCT-PR and OCT-CC than those without. Compared with patients without non-IR UMI, the prevalence of high pericoronary inflammation was higher in patients with non-IR UMI (Figure 1C). When the total cohort was divided into four groups according to the numbers of aforementioned OCT-derived risk factors and PCATA, patients with all of these UMI risk factors showed 46.2% (6/13) prevalence of non-IR UMI, whereas none of 15 patients without these factors showed non-IR UMI (Figure 1D).

Conclusions

When culprit lesion showed OCT-PR, OCT-CC, and high PCATA, about half of these patients are likely to have non-IR UMI. The integrated CCTA and OCT assessment may help identify the presence of non-IR UMI, potentially providing prognostic information in first NSTE-ACS patients.

Funding Acknowledgement

Type of funding sources: None.

Prognostic implications of fractional flow reserve and coronary flow reserve after newer-generation drug-eluting stent implantation

Background

FFR after percutaneous coronary intervention (PCI) has been reported to provide prognostic information. However, limited data are available regarding the prognostication by CFR in patients treated with elective PCI using newer generation DES.

Purpose

This study aimed to assess the prognostic value of post-procedural fractional flow reserve (FFR) and coronary flow reserve (CFR) after newer-generation drug-eluting stent implantation (DES).

Methods

A total of 466 stenoses in 466 patients underwent FFR-guided PCI. FFR and CFR measurements before and after PCI by a pressure-temperature sensor-tipped wire were performed. Follow-up data were studied to determine the predictors of target vessel failure (TVF), defined as death, target vessel-related nonfatal myocardial infarction, and unplanned clinically driven target vessel late revascularization. Prognostic value of post-PCI CFR was compared with that of FFR or FFR/CFR combination.

Results

After PCI completion, 13.7% showed post-PCI FFR ≤0.80 and 44.2% exhibited post-PCI CFR <2.5. Discordant results were observed in 42.5% (198/466). During 2.7 (1.8–3.3) years follow-up, 57 (12.2%) TVF were documented. The multivariable Cox proportional hazard regression analysis revealed that post-PCI FFR and post-PCI CFR were independent prognostic factors. ROC analysis revealed that the optimal cut-off values of post-PCI FFR and CFR values were 0.85 and 2.26, respectively. Significant differences in TVF were detected according to post-PCI FFR (≤0.85 vs >0.85: 17.8% vs 8.9%, P<0.05) and post-PCI CFR (≤2.26 vs >2.26: 20.5% vs 7.2%, P<0.01), although the reclassification ability for TVF was improved only with post-PCI CFR (net reclassification index 0.598; P<0.01; integrated discrimination index 0.038; P<0.01), but not with post-PCI FFR, in comparison with the clinical model. Compared with patients with FFR >0.85, those with post-PCI FFR ≤0.85 and CFR ≤2.26 showed significantly higher risk of TVF (8.9% vs 28.9%, P<0.01, HR 4.24, 95% CI 2.40–7.50, P<0.01), whereas those with post-PCI FFR <0.85 and CFR >2.26 had similar TVF risk (8.9% vs 9.2%, P=1.00, HR 1.01, 95% CI 0.47–2.16, P=0.97).

Conclusions

After PCI completion with newer-generation DES, discordant results between FFR and CFR were observed in 42.5%. Compared with post-PCI CFR, post-PCI FFR provided limited reclassification ability for TVF. Among patients with lower post-PCI FFR, only patients with lower post-PCI CFR showed significantly higher risk of TVF than those with higher post-PCI FFR.

Funding Acknowledgement

Type of funding sources: None.

Hyperaemic and non-hyperaemic pressure indices of coronary stenosis severity in patients with chronic kidney disease

Background

Evidence regarding the use of pressure indices for the assessment of coronary stenoses in patients with chronic kidney disease (CKD) is scarce.

Methods

We assessed the relation between eGFR, FFR and resting Pd/Pa in 1147 consecutive patients (1316 vessels) included in the International Collaboration of Comprehensive Physiologic Assessment Study. We also compared FFR and Pd/Pa against a standardized cut-off of coronary flow reserve (CFR<2.0). Finally, we examined the occurrence of vessel-oriented composite outcome (VOCO: cardiac death, vessel-specific revascularization, vessel-specific myocardial infarction) across negative/positive results of both FFR and CFR in patients with and without CKD.

Results

FFR increases as renal function worsens (beta −10.5, 95% CI −20.0 to −11.03, p=0.030), a relation that was not seen with resting Pd/Pa (beta −6.14, 95% CI −19.9 to 6.78, p=0.351). Both indices had similar diagnostic accuracies for the detection of a CFR<2.0 in the presence of CKD (AUC 0.629 for FFR vs 0.663 for resting Pd/Pa, p=0.192). However, CKD patients showed a higher proportion of vessels with negative FFR but low CFR (24.5% vs 13.4%, p=0.015).

CFR decreased linearly with deteriorating eGFR, and this was mainly driven by higher resting coronary flow in CKD patients (p=0.026), while hyperaemic coronary flow remained similar (p=0.403). IMR did not change significantly with eGFR (beta −0.02, 95% −0.09 to 0.05, p=0.557).

The incidence of VOCO was higher in patients with CKD and FFR>0.80 when compared to non-CKD patients and FFR>0.80 (12.7% vs 6.90%, p=0.062). Prognosis was worse for those with CKD, negative FFR and CFR<2.0 (20.59% vs. 8.44% in non-CKD, p=0.038).

Conclusions

The assessment of a given coronary stenosis in patients with CKD with either FFR or resting Pd/Pa is equivalent when compared to underlying coronary flow. In CKD, impaired CFR is caused by a state of increased resting flow. The assessment of CFR on top of standard pressure wire examination significantly improves prognostic stratification in CKD patients.

Funding Acknowledgement

Type of funding sources: None.

Robust association between changes in coronary flow capacity following PCI and vessel-oriented outcomes

Backgrounds

While trials show a comparative effectiveness of percutaneous coronary intervention (PCI) against medical therapy with respect to patient outcomes, deferring all elective PCI might be too simplistic, given the prognostic benefit differential according to several factors. Coronary flow capacity (CFC) is a potentially useful coronary flow (CF)-related physiologic marker of ischemia for guiding PCI indication [1,2]. However, the physiological/prognostic mechanics of the CFC guidance, which could be assessed by CFC changes following PCI, have not been investigated.

Objectives

To assess the determinants and prognostic implication of the change in the CFC status following PCI.

Methods

From a single center registry, 450 patients with chronic coronary syndrome (CCS) who underwent fractional flow reserve (FFR)-guided PCI with pre-/post-PCI coronary physiological assessments by thermodilution-method were included. CFC status was defined as follows [1]; normal CFC as CFR ≥2.80 with hyperemic CF (hCF) ≥3.70; mildly reduced CFC as CFR <2.80 and ≥2.10, combined with hCF <3.70 and ≥2.56; moderately reduced CFC as CFR <2.10 and ≥1.70, and 1/Tmn <2.56 and ≤2.00; and severely reduced CFC otherwise (CFR <1.70 and hCF <2.00). Associations between PCI-related changes in thermodilution method-derived CFC categories and incident target vessel failure (TVF) during a median follow-up of 4.3 (IQR: 2.5, 6.9) years were assessed by multivariate COX proportional hazard models.

Results

The mean (SD) age was 67.1 (10.0) years and there were 75 (16.7%) women. There were no differences in survival according to pre-PCI CFC status (P for linear trends = 0.22). Compared with patients showing no change in CFC categories after PCI, patients with category worsened, +1, +2, and +3 category improved had the hazard ratio (95% CI) for incident TVF of 2.27 (0.95, 5.43), 0.85 (0.33, 2.22), 0.45 (0.12, 1.63), and 0.14 (0.016, 1.30), respectively (P for linear trends = 0.0017). The relevant Kaplan-Meier curves were illustrated in the Figure, which highlights a best survival in those with +3 categories improvement (severely reduced to normal CFC) and worst in worsened CFC. After adjustment for confounders, one additional improvement in CFC status was associated with 0.61 (0.45, 0.83) times the hazard of TVF. CFC changes ≥3 categories were largely predicted by pre-PCI CFC with area under the curve of 0.94 (95% CI: 0.93, 0.96), and 48.6% of the variability of continuous CFC changes in ranks was explained solely by pre-PCI CFC, while only 12.4% by FFR.

Conclusion

CFC improvement following PCI, which was largely determined by the pre-PCI CFC status, was associated with lower risk of incident TVF in patients with CCS who underwent PCI. Therefore, CFC changes provide a mechanistic explanation on a potential favorable effect of PCI on reducing vessel-oriented outcome in lesions with reduced CFC and low FFR.

Funding Acknowledgement

Type of funding sources: None.

Relationship between OCT-derived plaque characteristics, CTA-derived coronary inflammation, and CMR-derived global coronary flow reserve in patients with acute coronary syndrome

Background

The presence of layered plaque is suggestive of recurrent thrombotic events. However, the impact of layered plaque detected by optical coherence tomography (OCT) on coronary inflammation and coronary flow reserve remains unclear.

Purpose

We aimed to investigate the association of OCT-derived layered plaque with pericoronary adipose tissue inflammation assessed by coronary computed tomography angiography (cCTA) and global coronary flow reserve (G-CFR) assessed by cardiac magnetic resonance imaging (CMR) in patients with acute coronary syndrome (ACS).

Methods

We investigated 88 patients with first ACS who underwent preprocedural cCTA and OCT imaging of the culprit lesion, and CMR after percutaneous coronary intervention (PCI). All patients were divided into four groups according to the OCT-derived culprit plaque characteristics: layered vs. non-layered plaque; and plaque rupture vs. plaque erosion. Coronary inflammation was assessed by the mean value of pericoronary adipose tissue (PCAT) attenuation (−190 to −30 HU) of the three major coronary vessels. G-CFR was obtained by quantifying absolute coronary sinus flow at rest and during maximum hyperemia. CCTA and CMR findings were compared between the groups.

Results

In a total of 88 patients, layered plaque [L] with plaque rupture [PR] was observed in 25 patients, layered plaque with plaque erosion [PE] was observed in 26 patients, non-layered plaque [NL] with PR was observed in 23 patients, and non-layered plaque with PE was observed in 14 patients, respectively. Three-vessel-PCAT attenuation value (L-PR vs. L-PE vs. NL-PR vs. NL-PE; −68.13±6.18 vs. −69.01±6.72 vs. −69.76±4.04 vs. −74.61±5.63 HU, P=0.009) and culprit vessel PCAT attenuation value (L-PR vs. L-PE vs. NL-PR vs. NL-PE; −66.39±7.38 vs. −68.94±8.06 vs. −70.01±5.76 vs. −75.45±6.60 HU, P=0.003) showed the graded difference between the four groups. G-CFR value also showed the graded difference between the four groups (L-PR vs. L-PE vs. NL-PR vs. NL-PE; 2.26 [1.80–2.87] vs. 2.24 [1.72–3.13] vs. 2.97 [2.24–3.83] vs. 3.18 [2.67–4.08], P=0.022).

Conclusions

The presence of layered plaque at the culprit lesion was associated with high PCATA and low G-CFR in patients with ACS. Detection of layered plaque may indicate increased pericoronary inflammation and impaired coronary flow reserve, potentially providing the risk stratification in patients with ACS.

Funding Acknowledgement

Type of funding sources: None.

[β-Catenin Expression in Non-Small Cell Lung Cancer and Therapeutic Effect of Immune Checkpoint Inhibitors]

Recently, β-catenin mediated immune escape mechanism has been reported in several cancers. We investigated whether β-catenin is associated with resistance to immune checkpoint inhibitor therapy in non-small cell lung cancer. Non-small cell lung cancer patients expressing high levels of β-catenin showed poor progression-free survival and overall survival after single agent anti-PD-1 therapy. They had less infiltration of CD8-positive cells and antigen-presenting cells. Microarray analysis also showed low gene expression of CD8A and IFNG. siRNA knockdown of CTNNB1 in the β-catenin-positive lung cancer cell line LK-2 tended to decrease CTNNB1 and ATF3 expression and increase CCL4 expression. The results suggest that β- catenin suppresses tumor infiltration by antigen-presenting cells and confers resistance to immune checkpoint inhibitors in non-small cell lung cancer via downregulation of CCL4 production.

[Resistance Mechanisms to Immune Checkpoint Inhibitor and Its Overcome with Focus on β-Catenin in Lung Cancer]

Although the indications for immune checkpoint inhibitors are expanding rapidly, the disease will eventually progress in many patients. Elucidating and overcoming the resistant mechanisms to immune checkpoint inhibitors is a major challenge. WNT/β-catenin pathway has long been known as one of the mechanisms involved in cell proliferation and epithelial-mesenchymal transition in cancer development. Recently, it has become clear that WNT/β-catenin pathway also plays a role in cancer immune escape, as reported in melanoma. We have also studied WNT/β-catenin pathway as a mechanism of immune escape in lung cancer. In this article, we review how WNT/β-catenin pathway is involved in immune escape and resistance to immune checkpoint inhibitors, mainly in non-small cell lung cancer. In addition, we discuss how to overcome the tumor immune mechanism caused by WNT/β-catenin pathway in the context of current combination therapies and therapies in development.

Direct observations of pure electron outflow in magnetic reconnection

Magnetic reconnection is a universal process in space, astrophysical, and laboratory plasmas. It alters magnetic field topology and results in energy release to the plasma. Here we report the experimental results of a pure electron outflow in magnetic reconnection, which is not accompanied with ion flows. By controlling an applied magnetic field in a laser produced plasma, we have constructed an experiment that magnetizes the electrons but not the ions. This allows us to isolate the electron dynamics from the ions. Collective Thomson scattering measurements reveal the electron Alfvénic outflow without ion outflow. The resultant plasmoid and whistler waves are observed with the magnetic induction probe measurements. We observe the unique features of electron-scale magnetic reconnection simultaneously in laser produced plasmas, including global structures, local plasma parameters, magnetic field, and waves.

High-power laser experiment forming a supercritical collisionless shock in a magnetized uniform plasma at rest

We present an experimental method to generate quasiperpendicular supercritical magnetized collisionless shocks. In our experiment, ambient nitrogen (N) plasma is at rest and well magnetized, and it has uniform mass density. The plasma is pushed by laser-driven ablation aluminum (Al) plasma. Streaked optical pyrometry and spatially resolved laser collective Thomson scattering clarify structures of plasma density and temperatures, which are compared with one-dimensional particle-in-cell simulations. It is indicated that just after the laser irradiation, the Al plasma is magnetized by a self-generated Biermann battery field, and the plasma slaps the incident N plasma. The compressed external field in the N plasma reflects N ions, leading to counterstreaming magnetized N flows. Namely, we identify the edge of the reflected N ions. Such interacting plasmas form a magnetized collisionless shock.

CTLA-4 Expression in Tumor-infiltrating Lymphocytes Is Irrelevant to PD-L1 Expression in NSCLC

BACKGROUND/AIM

Treatments containing ipilimumab have shown a good outcome in patients with non-small cell lung cancer (NSCLC) regardless of the PD-L1 tumor proportion score (TPS). However, the association between PD-L1 TPS and the expression of CTLA-4 in tumor-infiltrating lymphocytes is unknown.

PATIENTS AND METHODS

Fifty-five NSCLC patients who underwent surgery in our hospital were included in this study. We measured the proportions of CTLA-4⁺ regulatory T cells, and CTLA-4⁺ CD8 T cells, and statistically analyzed their correlations with the PD-L1 TPS.

RESULTS

Statistical correlations were found neither between the proportion of CTLA-4⁺ regulatory T cells to CD8 T cells and the PD-L1 TPS (p=0.2859) nor between the proportion of CTLA-4⁺ cells in CD8 T cells and the PD-L1 TPS (p=0.1919).

CONCLUSION

The proportions of CTLA-4⁺ regulatory T cells to CD8 T cells and CTLA-4⁺ cells in CD8 T cells were irrelevant to the PD-L1 TPS in NSCLC patients.

The clinical significance of tertiary lymphoid structure and its relationship with peripheral blood characteristics in patients with surgically resected non-small cell lung cancer: a single-center, retrospective study

INTRODUCTION

The presence of tertiary lymphoid structure (TLS) in tumor tissues has been reported to be a factor associated with a good prognosis in several types of cancers. However, the relationship between TLS formation and peripheral blood findings remains unclear. The purposes of the study were to evaluate the effect of the presence of TLS on survival and determine the peripheral blood characteristics associated with TLS formation in non-small cell lung cancer (NSCLC) patients.

METHODS

A total of 147 consecutive NSCLC patients who underwent lung resection at Fukushima Medical University Hospital between 2013 and 2017 were enrolled. TLS expression was evaluated, and the relationships between clinical parameters and outcomes were analyzed. Peripheral blood mononuclear cells (PBMCs) were further analyzed by mass cytometry to characterize the TLS-positive microenvironment.

RESULTS

Forty-six patients had high TLS expression, and the remaining 101 patients had low TLS expression. In stage II to IV patients (n = 35), disease-free survival was longer in the high TLS expression group (p = 0.027). A low neutrophil to lymphocyte ratio (NLR) < 2.75 in the peripheral blood was associated with high TLS expression (p = 0.003). Citrus analysis after mass cytometry assay showed that the number of cells expressing HLA-DR and CD9 in PBMCs was lower in the high TLS expression group.

CONCLUSION

High TLS expression is associated with a good prognosis after surgery in stage II and III NSCLC patients. In the peripheral blood, a low NLR and few antigen-presenting cells indicate the presence of TLS in the tumor microenvironment.

Diagnostic Accuracy of Diastolic Fractional Flow Reserve for Functional Evaluation of Coronary Stenosis

Background

In the resting conditions, narrowing the window of coronary pressure measurements from the whole cardiac cycle to diastole improves diagnostic performance of coronary pressure–derived physiological index. However, whether this also applies to the hyperemic conditions has not yet been thoroughly evaluated.

Objectives

The purpose of this study was to assess whether diastolic fractional flow reserve (diastolic FFR) has better diagnostic performance in identifying ischemia-causing coronary lesions than conventional FFR in a prospective, multicenter, and independent core laboratory–based environment.

Methods

In this prospective multicenter registry at 29 Japanese centers, we compared the diagnostic performance of FFR, diastolic FFR, resting distal to aortic coronary pressure (Pd/Pa), and diastolic pressure ratio (dPR) using myocardial perfusion scintigraphy (MPS) as the reference standard in 378 patients with single-vessel coronary disease.

Results

Inducible myocardial ischemia was found on MPS in the relevant myocardial territory of the target vessel in 85 patients (22%). In the receiver-operating curve analyses, diastolic FFR had comparable area under the curve (AUC) compared with FFR (AUC_{diastolic FFR}: 0.66; 95% confidence interval [CI]: 0.58-0.73, vs AUC_FFR: 0.66; 95% CI: 0.58-0.74, P = 0.624). FFR and diastolic FFR showed significantly larger AUCs than resting Pd/Pa (0.62; 95% CI: 0.54-0.70; P = 0.033 and P = 0.046) but did not show significantly larger AUCs than dPR (0.62; 95% CI: 0.55-0.70; P = 0.102 and P = 0.113).

Conclusions

Diastolic FFR showed a similar diagnostic performance to FFR as compared with MPS. This result reaffirms the use of FFR as the most accurate invasive physiological lesion assessment. (Diagnostic accuracy of diastolic fractional flow reserve (d-FFR) for functional evaluation of coronary stenosis; UMIN000015906)

Delta-like 1 homolog (DLK1) as a possible therapeutic target and its application to radioimmunotherapy using 125I-labelled anti-DLK1 antibody in lung cancer models (HOT1801 and FIGHT004)

OBJECTIVES

Delta-like 1 homolog (DLK1) is a non-canonical Notch ligand known to be expressed in several cancers but whose role in lung cancer is not yet fully understood. We sought to confirm DLK1 expression in small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC), and to examine DLK1's clinical significance. Furthermore, we examined the possible utility of DLK1 as a novel target in radioimmunotherapy (RIT).

METHODS

We retrospectively assessed the correlation between clinical features and DLK1 expression by immunohistochemistry in resected specimens from 112 patients with SCLC and 101 patients with NSCLC. Moreover, we performed cell and animal experiments, and examined the possibility of RIT targeting DLK1 in SCLC using iodine-125 (¹²⁵I) -labeled anti-DLK1 antibody, knowing that ¹²⁵I can be replaced with the alpha-particle-emitter astatine-211 (²¹¹At).

RESULTS

In SCLC and NSCLC, 20.5 % (23/112) and 16.8 % (17/101) of patients (respectively) had DLK1-positive tumors. In NSCLC, DLK1 expression was associated with recurrence-free survival (P < 0.01) but not with overall survival. In SCLC, there was no association between DLK1 expression and survival. In addition, ¹²⁵I-labeled anti-DLK1 antibody specifically targeted DLK1 on human SCLC tumor cell lines. Furthermore, ¹²⁵I-labeled anti-DLK1 antibody was incorporated into tumor tissue in a mouse model.

CONCLUSION

A proportion of SCLC and NSCLC exhibits DLK1 expression. As a clinical feature, DLK1 expression could be a promising prognostic factor for recurrence in patients with resected NSCLC. In addition, DLK1 could serve as a new therapeutic target, including RIT, as suggested by our pilot study using a radiolabeled anti-DLK1 antibody in SCLC.

Tumor β-catenin expression is associated with immune evasion in non-small cell lung cancer with high tumor mutation burden

β-catenin expression by tumor cells suppressed dendritic cell recruitment to the tumor microenvironment in a melanoma model, resulting in fewer tumor-infiltrating lymphocytes. Immunohistochemistry was used in the present study to examine the association between the expression of β-catenin and tumor infiltrating lymphocytes and CD11c⁺ cells in 122 patients with non-small cell lung cancer (NSCLC), who underwent radical surgery. β-catenin was positive in 24% of NSCLC tumors compared with 59% of squamous cell carcinomas and 11% of adenocarcinomas. There was no significant association between the expression of β-catenin and the frequency of CD8⁺ cell infiltration into tumor tissues, including the stroma. Conversely, the infiltration of CD8⁺ cells into tumor nests was significantly lower in β-catenin-positive cases compared with that in negative β-catenin cases. Similarly, CD11c⁺ cell infiltration was significantly lower in the β-catenin-positive group. The β-catenin-positive group had shorter overall survival and recurrence-free survival times compared with that in the negative group. Furthermore, β-catenin-positive NSCLC had a high tumor mutation burden, but tended to have a low expression of programmed death-ligand 1. In conclusion, the expression of β-catenin in NSCLC was negatively associated with CD11c⁺ cells and cytotoxic T cell infiltration at the tumor site and had a tendency towards a poor prognosis.

Prognostic value of peri-coronary adipose tissue attenuation and whole vessel and lesion plaque quantification on Coronary Computed Tomography Angiography

Background

Peri-coronary adipose tissue attenuation expressed by fat attenuation index (FAI) on coronary CT angiography (CCTA) reflects peri-coronary inflammation and is associated with cardiac mortality. CCTA also provides two-dimensional and three-dimensional quantification of the individual component of atherosclerotic plaque and entire vessel. The atherosclerotic burden or disease extent in entire epicardial coronary arteries provides prognostic information in patients with coronary artery disease.

Purpose

This study sought to explore the prognostic significance of FAI values and whole vessel and lesion plaque quantification on CCTA in stable patients with intermediate epicardial stenosis evaluated by fractional flow reserve (FFR).

Methods

A total of 277 patients (277 lesions) with intermediate coronary stenosis who underwent FFR measurement and CCTA were studied. FAI was assessed by the crude analysis of the mean CT attenuation value (−190 to −30 Hounsfield units; higher values indicating inflammation) on CCTA. CT findings including whole vessel and lesion plaque quantification, and target vessel myocardial mass were investigated. Major adverse cardiovascular outcome (MACE) was defined as all cause death, cardiac death, myocardial infarction, unplanned revascularization, and heart failure requiring admission. Survivals from MACE were assessed.

Results

The mean FAI and the median FFR values were −71.6 and 0.77, respectively. FFR values were weakly albeit significantly correlated with FAI values. (r=−0.016, P=0.008.) MACE was occurred 43 (15.5%) patients during 5 years F-up. ROC analyses revealed that best cut-off value of FAI to predict MACE was −73.1. Kaplan-Meier analysis revealed that lesions with FAI ≥−73.1 had a significantly higher risk of MACE. (Chi-square 5.5, P=0.019) FFR values and the percutaneous coronary intervention were not predictive of MACE. Multivariate COX proportional hazards regression analysis revealed that age, remodeling index, and lesions with FAI ≥−73.1 were independent predictors of MACE.

Conclusion

The peri-coronary inflammation evaluated by FAI and CT remodeling index enhances cardiac risk prediction in chronic coronary syndrome patients with intermediate lesions. Non-invasive comprehensive CT assessment may help identify high risk patients of subsequent clinical events and provide enhanced patient management.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): This study was supported in part by an unrestricted research grant from St. Jude Medical (Abbot Vascular, Santa Clara, CA, USA). The company had no role in study design, conduct, data analysis or manuscript preparation.

Prognostic value of unrecognized myocardial infarction and hyperemic coronary sinus flow in patients undergoing elective percutaneous coronary intervention

Background

Cardiac magnetic resonance (CMR) imaging is a useful instrument for the assessment of pathological and functional conditions without the need for ionizing radiation, radioactive tracers, or intravascular catheterization. Both unrecognized myocardial infarction (UMI) and impaired global myocardial blood flow (g-MBF) have been reported to be strongly associated with worse outcome in patients with cardiovascular disease. However, their combined efficacy remains undetermined.

Purpose

We sought to assess the prognostic value of the presence of UMI and pre-procedural hyperemic g-MBF evaluated by phase-contrast cine magnetic resonance imaging (PC-CMR) in patients with chronic coronary syndrome who underwent elective percutaneous coronary intervention (PCI).

Methods

A total of 177 patients with de novo functionally significant stenosis who underwent pre-PCI CMR and PCI between September, 2016 and March, 2019 were retrospectively studied. UMI was defined as a scar detected by late gadolinium enhancement (LGE) without previously diagnosed MI. g-MBF was assessed by quantifying coronary sinus flow using PC-CMR at rest and hyperemic state. The predictors of major adverse cardiac events (MACE; cardiac death, nonfatal myocardial infarction, clinically driven unplanned revascularization, or hospitalization for congestive heart failure) during follow-up were investigated.

Results

UMI was detected in 40 (27.7%) patients and rest and maximal hyperemic g-MBF evaluated by the coronary sinus flow obtained by PC-CMR were 0.95 ml/min/g and 2.26 ml/min/g, respectively. During the median follow-up of 26 months, cardiovascular death occurred in 1 patient (0.6%), nonfatal myocardial infarction occurred in 4 patients (2.3%), and clinically driven revascularization and hospitalization due to congestive heart failure occurred in 25 patients (14.1%) and 3 patients (1.7%) patients, respectively. In patients with MACE, hyperemic g-MBF was significantly lower and the prevalence of UMI were significantly higher compared with those without MACE (1.94 ml/min/g vs 2.36 ml/min/g P=0.014; 48.3% vs 23.6%, P=0.011). Cox proportional hazards model indicated that impaired hyperemic g-MBF (&lt;2.00 ml/min/g) and the presence of UMI were significant predictors of MACE (HR 2.22, 95% CI 1.060–4.640, P=0.034; HR 2.660, 95% CI 1.290–5.470, P=0.008). During follow-up, cardiac event-free survival was significantly worse in patients with impaired hyperemic g-MBF (&lt;2.00 ml/min/g) and UMI (log-rank χ2=11.0, P=0.010).

Conclusion

In patients with chronic coronary syndrome undergoing elective PCI, the combined assessment of UMI and hyperemic g-MBF obtained by preprocedural noninvasive CMR may provide significant prognostic information.

Funding Acknowledgement

Type of funding source: None

Prognostic value of pre-revascularization fractional flow reserve mediated by the post-revascularization level: a causal mediation analysis

Background

The prognostic value of pre-percutaneous coronary intervention (PCI) fractional flow reserve (FFR) can depend on that of the post-PCI FFR and their interaction. To correctly interpret the prognostic value of pre-PCI FFR, it is essential to understand to what extent the relationship between pre-PCI FFR and clinical outcome is explained by pre-PCI FFR-related post-PCI FFR.

Purpose

The aim of this study is to investigate the extent to which post-PCI FFR mediates the relationship between pre-PCI FFR and vessel-related outcomes using a global, multicenter collaboration registry.

Methods

Patient data from 4 global FFR registries were pooled and 1488 patients with pre-PCI FFR ≤0.80 were analyzed. The primary outcome was target vessel failure (TVF) during 2-years of follow-up. We evaluated the extent to which post-PCI FFR &lt;0.90 mediated the association between pre-PCI FFR &lt;0.75 and TVF employing a causal mediation analysis in a counterfactual framework.

Results

Among 1488 patients, the mean (standard deviation) age was 63.5 (9.9) years and 78% (1161 patients) were male. The median (IQR) pre-PCI and post-PCI FFR were 0.71 (0.62–0.76) and 0.88 (0.83–0.92), respectively. The direct effect of low pre-PCI FFR (&lt;0.75) on TVF was significantly elevated (OR: 1.81, 95% CI: 1.03–3.18, p=0.038), and was not mediated by post-PCI FFR&lt;0.90 (indirect effect, OR: 1.01, 95% CI: 0.98–1.05, p=0.39). In the model, post-PCI FFR explained only 2.2% of the association between pre-PCI FFR and TVF. The subgroup analysis implicated that the prognostic information of pre-PCI FFR was mainly for diffuse lesions.

Conclusions

The prognostic information of pre-PCI FFR did not greatly depend on the results of PCI assessed by post-PCI FFR. Pre-PCI FFR, as a prognostic marker, may mainly reflect the global atherosclerotic burden of the artery, not the extent of the modifiable epicardial stenosis, thus providing independent information from post-PCI FFR.

Interpretation

Funding Acknowledgement

Type of funding source: None

Prognostic value of fat attenuation index of pericoronary adipose tissue surrounding left anterior descending artery on coronary computed tomography angiography

Background

Recent studies reported the association between elevated fat attenuation index (FAI) of pericoronary adipose tissue (PCAT) on coronary computed tomography angiography (CTA) and worse cardiac outcomes.

Purpose

We investigated the prognostic value of increased FAI-defined coronary inflammation status in patients with coronary artery disease.

Methods

Three-hundred fifty-eight patients (127 acute coronary syndromes [ACS], 231 stable coronary artery disease) with left anterior descending artery (LAD) as a culprit vessel who underwent coronary CTA were retrospectively studied. The FAI defined as the mean CT attenuation value of PCAT (−190 to −30 Hounsfield Unit [HU]) was measured at the proximal 40-mm segment of LAD. All subjects were divided into two groups according to the median value of FAI in the LAD. The association between the incidence of major adverse cardiac events (MACE) including all-cause death, myocardial infarction, heart failure, target and non-target vessel revascularization were evaluated.

Results

In a total of 358 patients, median FAI values surrounding the LAD was −71.46 (interquartile range, −77.10 to −66.34) HU. Thirty-eight patients (10.6%) experienced MACE during the follow-up period (median, 818 days). Kaplan-Meier analysis revealed that high FAI-LAD (&gt;−71.46 HU [median]) was significantly associated with the incidence of MACE (log-rank test, chi-square = 4.183, P=0.041) (Figure).

Conclusions

In patients with coronary artery disease with culprit LAD lesions, elevated FAI of PCAT surrounding the LAD was associated with worse clinical outcomes. Assessment of FAI may have a potential for potential for non-invasive risk-stratification by coronary CTA.

Kaplan-Meier analysis for MACE

Funding Acknowledgement

Type of funding source: None

Impact of neoatherosclerosis observed at very late phase after coronary stent implantation on subsequent adverse events

Background

Despite the reduction in late thrombotic events with newer generation coronary stents, late stent failure remains a concern following stent implantation. Neoatherosclerosis (NA) is a cause of in-stent restenosis and acute thrombotic occlusion originating from the stented segment by disruption of the in-stent atheroma. Although the clinical impact of NA at 1 year has been reported, clinical significance of NA observed at very later phase remains to be determined. We sought to investigate the association between optical coherence tomography (OCT) findings at very late phase after stenting and subsequent clinical outcomes.

Methods

A total of 195 patients with 316 stents (including 74 bare metal stents, 48 first-generation DES, and 194 second-generation DES) without stent failure who underwent OCT examination at &gt;3 years (4.9 [3.9- 5.8] years) after stent implantation according to the prespecified protocol were investigated. OCT analysis included the presence of lipid-laden neointima, macrophage, malapposition, thrombus, and plaque rupture within the stents. NA was defined as having lipid-laden neointima. The criteria for the diagnosis of NA were signal-poor region in continuous flames, lipid length longer than 0.3 mm, and invisible stent strut at NA site. Quantitative OCT measurement included lipid length (LL), lipid arc, minimum lumen area (MLA) at the stented segment and minimum stent area (MSA). Major adverse cardiac events (MACE) including all-cause death, non-fatal myocardial infarction, and clinically driven revascularization were assessed. MACE-free survival rate was compared between patients with stent showing NA (NA group) and those without NA (non-NA group). Furthermore, in per-stent basis analysis, stent failure including remote revascularization and stent thrombosis of the stent after follow-up OCT examination was assessed.

Results

NA was identified in 50 stents (15.8%) in 38 patients (19.5%). During the median follow-up period of 2.1 [1.0- 2.8] years after OCT examination, 15 MACEs (7.7%) were captured in the total cohort, of which stent failure was observed in 5 stents (5/316, 1.6%). In patient-based analysis, patients with NA had more frequent MACE than those without (18.0% vs 5.1%, p=0.01). Kaplan-Meier analysis revealed that significantly higher MACE rate was detected in NA group than in non-NA group (χ2=5.4, Log-rank p=0.02). In stent-based analysis, NA stents had more frequent stent failure than those without (8.0% vs 0.4%, p=0.002)

Conclusions

NA observed by OCT at &gt;3 years after implantation were associated with subsequent worse clinical outcomes in both patient and stent-based analysis. NA at the very late phase after stenting might be the therapeutic target of secondary prevention and OCT examination at very late phase after stenting may help identify high risk patients of subsequent MACE.

Funding Acknowledgement

Type of funding source: None

Prognostic value of coronary flow capacity assessed by coronary sinus flow obtained by phase contrast cine-magnetic resonance imaging in patients with acute coronary syndrome

Background

The concept of coronary flow capacity (CFC) originated from positron emission tomography has been reported to provide prognostic information. Phase contrast cine-magnetic resonance imaging (PC-CMR) of the coronary sinus (CS) is a promising approach for quantifying global coronary sinus flow (CSF) and global coronary flow reserve (g-CFR) without the need for ionizing radiation, radioactive tracers, or intravascular catheterization.

Purpose

We evaluated the prognostic value of postprocedural CFC by quantifying CSF using PC-CMR in patients with acute coronary syndrome (ACS) treated with primary or urgent percutaneous coronary intervention (PCI).

Methods

This study prospectively but nonconsecutively enrolled 569 ACS patients who underwent uncomplicated primary (for ST-segment elevation myocardial infarction (STEMI)) or urgent PCI within 48 hours of symptom onset (for non-ST elevation acute coronary syndrome (NSTE-ACS)). Breath-hold PC-CMR images of CS were acquired to assess absolute CSF at rest and during maximum hyperemia within 30 days after culprit lesion PCI and revascularization of functionally significant non-culprit lesions. The entire cohort was stratified by the CFC according to the thresholds of hyperemic CSF and g-CFR. Impaired CFC was defined as a severely-reduced CFC in the present study. The association of CFC and baseline clinical characteristics with major adverse cardiac events (all-cause death, nonfatal myocardial infarction, hospitalization for congestive heart failure or stroke) was investigated.

Results

In the final analysis of 502 patients (Male 417 (83.1%), mean age was 67 [58, 73]) and 310 patients (82.3%) with STEMI and 192 patients (38.2%) with NSTE-ACS were studied. In a total cohort, rest and maximal hyperemic CSF and corrected G-CFR were 0.93 [0.68, 1.24] ml/min/g, 2.08 [1.44, 2.77] ml/min/g, and 2.21 [1.58, 3.05], respectively. During a median follow-up of 28 months, MACE occurred in 53 patients (all-cause death: 19, nonfatal myocardial infarction: 16, late revascularization: 59, hospitalization for congestive heart failure: 9, stroke: 9). Cox proportional hazards analysis showed that corrected G-CFR and impaired CFC were both independent predictors of MACE. (hazard ratio (HR), 0.61, 95% confidence interval (CI): 0.45–0.82, p=0.001; HR, 3.51, 95% CI: 1.79–6.86, p≤0.001, respectively). Cardiac event-free survival was significantly worse in patients with impaired CFC (log-rank χ2=22.9, P&lt;0.001). Net reclassification index (NRI) and integrated discrimination improvement (IDI) were both significantly improved when impaired CFC was added to the clinical risk model for predicting MACE.

Conclusions

In ACS patients successfully revascularized with primary or urgent PCI, CFC categorization stratified by noninvasive PC-CMR provided significant prognostic information independent of infarction size, conventional risk factors and g-CFR.

Funding Acknowledgement

Type of funding source: None

Association between near-infrared spectroscopy defined lipid rich plaque and pericoronary adipose tissue inflammation on computed tomography angiography

Background

A recent study has shown that lipid-rich plaque (LRP) detected by near-infrared spectroscopy (NIRS) is a significant predictor of future adverse events. Pericoronary adipose tissue inflammation (FAI; fat attenuation index) evaluated by computed tomography angiography (CTA) has also been reported to be linked with cardiac events. The relationship between NIRS-defined LRP and FAI remains to be determined.

Methods

A total of 82 de novo culprit lesions in 82 patients with chronic coronary syndromes (CCS) who underwent perprocedural CTA and NIRS was retrospectively studied. FAI was assessed by the crude analysis of the mean CT attenuation value (−190 to −30 Hounsfield units; higher values indicating inflammation) of pericoronary adipose tissue. Plaque morphology was assessed by coronary CTA and grey-scale intravascular ultrasound (IVUS). NIRS-defined LRP was defined as a maximum lipid core burden index (LCBI) in 4 mm ≥400. Relationship between NIRS-defined LRP, CTA/grey-scale IVUS findings, and FAI was assessed. Univariate and multivariate logistic regression analyses were performed to determine the predictors for NIRS-derived LRP.

Results

NIRS-defined LRP was observed in 35 (42.6%) patients. Maximum LCBI showed modest correlations both with FAI (r=0.29, p-value=0.007) and CT-derived remodeling index (r=0.51, p&lt;0.001). Receiver operating characteristic (ROC) curve analysis revealed that the best cut-off values of FAI and CT-derived remodeling index for predicting NIRS-defined LRP were −70.7 (AUC: 0.65, 95% CI: 0.53–0.71, P&lt;0.05) and 1.11 (AUC: 0.74, 95% CI: 0.63–0.86, P&lt;0.01), respectively. Multivariate logistic regression analysis showed FAI ≥−70.7 (odds ratio [OR]: 4.27; 95% CI: 1.28–14.3; p-value = 0.02) and CT-derived remodeling index (OR: 10.7; 95% CI: 2.99–32.2; p-value &lt;0.001) were independent predictors of the presence of NIRS-defined LRP, whereas there was no statistically significant and independent predictor of IVUS-derived factors for NIRS-defined LRP. When stratified according to the presence or absence of FAI ≥−70.7 and CT-derived remodeling index ≥1.11, 93% of the lesions showed NIRS-derived LRP when both factors were present, and NIRS-derived LRP was safely ruled out (88%) when both factors were absent.

Conclusions

FAI of the culprit lesion in CCS was an independent predictor of NIRS-defined LRP, supporting the notion that local pericoronary adipose tissue inflammation may correlate to the presence of LRP. Comprehensive assessment of coronary CTA including FAI evaluation may provide a highly accurate information with high sensitivity and specificity for identifying high risk lesions potentially leading to future cardiac events.

Funding Acknowledgement

Type of funding source: None

Clinical significance of the periaortic adipose tissue inflammation in patients with abdominal aortic aneurysms

Background

Recent studies have reported the association between periaortic adipose tissue volumes identified by multi-detector computed tomography (MDCT) and the periaortic adipose tissue inflammation (PATI) identified by positron emission tomography, which may suggest the link between perivascular inflammation and aortic dilation. However, clinical significance of the PATI identified by MDCT remains elusive in patients with asymptomatic abdominal aortic aneurysm (AAA).

Methods

A total of 77 patients with AAA (diameter &gt;30mm) who underwent the initial and follow-up MDCT examinations were studied retrospectively. PATI was assessed by the crude analysis of the mean CT attenuation value (−190 to −30 Hounsfield units; higher values indicating inflammation). The AAA progression (AP) was defined as the growth of AAA diameter &gt;5.0mm/year from the initial to follow-up. Univariate and multivariate logistic regression analysis were performed to determine the predictors for AP.

Results

AP was observed in 19 (24.7%) patient, the median initial AAA diameter was 38.9 (32.7–42.9) mm, and the median progression of AAA diameter was 3.1 (1.5–4.9) mm/year. The initial AAA diameter (odds ratio [OR]: 1.16; 95% confidence interval [CI]: 1.05–1.28; p-value=0.001) and the initial PATI (OR: 1.12; 95% CI: 1.05–1.20; p-value=0.004) were independent predictors of AP. PATI of −71.08 at initial MDCT and the initial AAA diameter of 37.7mm were the best cut-off value to predict AP. Receiver operating characteristic curve analysis revealed that the best cut-off values of PATI at initial MDCT and the initial AAA diameter for predicting AP were −71.08 (AUC: 0.68, 95% CI: 0.50–0.82) and 37.7 (AUC: 0.71, 95% CI: 0.59–0.84), respectively. Addition of the initial AAA diameter to PATI at initial MDCT significantly increased the accuracy for discriminating AP (net reclassification improvement; 95% CI: 0.67 [0.17–1.17]; p-value = 0.007, integrated discrimination improvement; 95% CI: 0.14 [0.04–0.24]; p-value =0.007).

Conclusions

PATI was an independent and significant predictor of aortic dilation, supporting the notion that local adipose tissue inflammation may contribute to aortic remodeling. Comprehensive assessment of MDCT including PATI evaluation may provide a highly accurate information for identifying high risk lesions potentially leading to future AAA rupture.

Funding Acknowledgement

Type of funding source: None

Impact of pericoronary inflammation assessed by coronary computed tomography angiography on the progression of aortic valve calcification

Background

Aortic valve calcification (AVC) has been known as an independent predictor for adverse cardiovascular events and all-cause mortality. Previous studies demonstrated that AVC was associated with aortic valve inflammation and atherosclerosis. However, the relationship between the progression of AVC and pericoronary inflammation remains undetermined.

Purpose

The purpose of this study was to evaluate the impact of the pericoronary inflammation on the progression of AVC.

Methods

A total of 107 patients with suspected or known chronic coronary syndromes who underwent clinically indicated serial 320-slice coronary computed tomography angiography (CTA) at Tsuchiura Kyodo General Hospital from January 2011 to June 2019 were retrospectively studied. Pericoronary inflammation was assessed by pericoronary adipose tissue attenuation (PCATA) defined as the mean CT attenuation value of PCATA (−190 to −30 Hounsfield units [HU]) on proximal 40 mm segments of coronary arteries. AVC was quantified by Agatston score on CTA. The mean aortic attenuation (HU Aorta) and the standard deviation (SD) in the region of interest at the level of the sinotubular junction was measured. AVC was defined as the threshold for calcium detection (mean HU Aorta + 2SD). AVC index was calculated as follows: (follow-up/baseline) AVC divided by follow-up period. AVC progression was defined as newly-developed AVC at follow-up or an increased AVC index during follow-up. All patients were divided into two groups according to the presence or absence of AVC progression, and clinical characteristics and CT findings were compared between these two groups.

Results

AVC progression was observed in 26 patients (24.3%) between 2 serial CT examinations (median, 34 months). There was no significant difference in age, gender and the prevalence of other cardiovascular risk factors between the 2 groups. Patients in AVC progression group were associated with higher prevalence of elevated PCATA-LAD, higher LV mass index at baseline and the initial AVC presence. Receiver-operating characteristic curve analysis revealed that the optimal cut off value of PCATA-LAD for predicting AVC progression was −68.26 HU (area under the curve 0.605; 95% confidence interval [CI], 0.465–0.745). Multivariable logistic regression analysis revealed that baseline PCATA-LAD ≥−68.26 HU (odds ratio [OR], 3.12; 95% CI, 1.04–9.35, p=0.042) and the presence of baseline positive AVC (OR, 6.84; 95% CI, 2.34–20.0, p=0.0004) were independent predictors of AVC progression.

Conclusions

The increased pericoronary inflammation and the presence of AVC may help identify patients with high risk for future AVC progression.

Funding Acknowledgement

Type of funding source: None

[Monitoring Tumor Infiltrating Lymphocytes by Peripheral Blood in Lung Cancer Patients]

There have been many reports on the association between tumor infiltrating lymphocytes and cancer prognosis. It is known that tumor infiltrating lymphocytes contain not only cytotoxic T lymphocytes but also bystander lymphocytes and immunosuppressive cells. In most of previous reports, tumor infiltrating lymphocytes were defined as CD3 or CD8 T cells. It is generally thought that patients with cancer rich in tumor infiltrating lymphocytes have a good prognosis. Most tumor infiltrating lymphocytes are thought to be cytotoxic T lymphocytes. It is also reported that cancer rich in tumor infiltrating lymphocytes is responsive to immune checkpoint inhibitors. In recent years, several reports revealed clonal replacement in tumor infiltrating lymphocytes after administration of immune checkpoint inhibitors. This change was also detectable in peripheral blood. From the viewpoint of lung cancer treatment, combination of immune checkpoint inhibitors and chemotherapy became the standard therapy. We need to understand the tumor immune microenvironment in order to select the best treatment regimen for each patient. However, it is often difficult to obtain an adequate amount of tissue biopsy sample in standard of care. It is hoped that we can understand the tumor immune microenvironment using the peripheral blood. Thus, studying the association between treatment response, tumor infiltrating lymphocytes, and peripheral blood is considered to be important to research and develop peripheral blood biomarkers in lung cancer.

The natural course of the paravertebral muscles after the onset of osteoporotic vertebral fracture

This study revealed the change in the paravertebral muscles in patients with osteoporotic vertebral fracture. Increased pain is likely to be the driver for reduced activity, reduced activities of daily living, and consequent increase in fat infiltration of the paravertebral muscles, assumed to be secondary to reduced activity level or, conversely, partial immobilization.

INTRODUCTION

To reveal the time courses and impact of the paravertebral muscles (PVMs) on the healing process of osteoporotic vertebral fractures and risk factors for PVM decrease.

METHODS

Consecutive patients with symptomatic osteoporotic vertebral fractures were enrolled in 11 hospitals. At enrollment and 3- and 6-month follow-up, PVMs, including the multifidus and erector spinae, were examined using magnetic resonance imaging (MRI). The PVM cross-sectional area (CSA) and fat signal fraction (FSF) were measured at L3. Low back pain (LBP), activities of daily living (ADLs), and risk factors for PVM decrease at the 6-month follow-up were investigated. PVM decrease was defined as > 1 standard deviation decrease of the CSA or > 1 standard deviation increase of the FSF.

RESULTS

Among 153 patients who completed the 6-month follow-up, 117 (92 women, 79%) had MRI of L3 at enrollment and 3- and 6-month follow-up (mean age at enrollment, 78.5 years). The CSA did not change 6 months from onset (p for trend = 0.634), whereas the FSF significantly increased (p for trend = 0.033). PVM decrease was observed in 30 patients (26%). LBP was more severe, and delayed union was more frequent in patients with PVM decrease (p = 0.021 mixed-effect model and p = 0.029 chi-square test, respectively). The risk factors for PVM decrease were ADL decline at the 3-month follow-up (adjusted odds ratio = 5.35, p = 0.026).

CONCLUSION

PVM decrease was significantly related to LBP and delayed union after osteoporotic vertebral fracture onset. ADL decline at the 3-month follow-up was a risk factor for PVM decrease. Therefore, restoring ADLs within 3 months after onset is important.

Genetic alterations in epidermal growth factor receptor-tyrosine kinase inhibitor-naïve non-small cell lung carcinoma

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) are an approved first-line therapy against unresectable or advanced non-small cell lung cancer (NSCLC) harboring EGFR gene activating mutations. However, the majority of tumors develop acquired resistance against EGFR-TKIs and some tumors exhibit natural resistance. A number of resistance mechanisms against the latest third-generation EGFR-TKIs have been reported, including tertiary EGFR C797S mutation and several gene alterations activating EGFR or other signaling pathways. The current study aimed to identify the frequency of natural EGFR-TKI resistance in pretreatment NSCLC and to predict the therapeutic effect of EGFR-TKIs. A total of 246 EGFR-TKI-naïve NSCLC patients harboring known EGFR gene mutations were identified. The presence of EGFR C797S and T790M mutations were determined using the peptide nucleic acid-locked nucleic acid PCR clamp method. ERBB2, MET, EGFR, ALK, BRAF, FGFR1, MYC, RET, CCND1, CCND2, CDK4, CDK6, MDM2 and MDM4 gene amplification, which can lead to resistance against any generation EGFR-TKIs, was determined using the multiplex ligation-dependent probe amplification assay. No concurrent C797S mutation with known EGFR mutations were identified. T790M mutation was identified in 12 patients (4.9%). ERBB2 or MET gene amplification was found in some patients (0.0-0.4%). MDM2 gene amplification was associated with tumor recurrence and shorter progression-free survival (PFS) for first- or second-generation EGFR-TKIs. De novo EGFR C797S mutation was not identified. Other resistance mechanisms against EGFR-TKIs were indicated in some patients with EGFR-TKI-naïve NSCLC. MDM2 gene amplification, which can lead to altered cell cycle, was associated with tumor recurrence and shorter PFS in EGFR-TKI therapy.

Observational Evidence for Stochastic Shock Drift Acceleration of Electrons at the Earth's Bow Shock

The first-order Fermi acceleration of electrons requires an injection of electrons into a mildly relativistic energy range. However, the mechanism of injection has remained a puzzle both in theory and observation. We present direct evidence for a novel stochastic shock drift acceleration theory for the injection obtained with Magnetospheric Multiscale observations at the Earth's bow shock. The theoretical model can explain electron acceleration to mildly relativistic energies at high-speed astrophysical shocks, which may provide a solution to the long-standing issue of electron injection.

P251 Right ventricular free wall dissection clearly detected and recorded by echocardiography: a fatal complication after inferior myocardial infarction

An 81-year-old man was transferred to our institution by ambulance because of poor feeding, general fatigue and slight disorientation lasting for a week. On arrival, he was awake and able to speak, however, his blood pressure was low at 61/43 mmHg in spite of his medical history of hypertension. His ECG showed abnormal Q waves and ST elevation in II, III, aVF leads. The echo exam detected severe hypokinesis in the left ventricular inferior wall and reduced ejection fraction at 30%. Pericardial effusion was not observed in the first echo exam. The patient was diagnosed as cardiogenic shock due to recent inferior myocardial infarction. Coronary angiography was performed, which detected total occlusion of mid right coronary artery, followed by a successful percutaneous coronary intervention (PCI) with a drug-eluting stent under the support of intra-aortic balloon pumping. Nevertheless, his blood pressure remained low and intravenous adrenaline administration was necessary during and even after PCI. To detect the cause of prolonged low blood pressure, echo was performed again immediately after PCI. The echo exam detected new findings: right ventricular posterior free wall was dissected and abnormal shunt flows were obviously observed from left ventricle to right atrium through the dissection cavity during systole. An urgent surgical repair was considered as the only option for his survival, however, his family did not accept it because the operation itself was too risky. On the next day of his admission, he passed away. Right ventricular free wall dissection is a very rare but fatal complication after inferior myocardial infarction, nevertheless, we could detect it by echocardiography with clearly recorded images.

Abstract P251 Figure.

P1386 A change in left ventricular global longitudinal strain is a prognostic indicator in congestive heart failure patients with preserved ejection fraction

Purposes

We examined how changes in left ventricular (LV) global longitudinal strain (GLS) were associated with prognosis in patients with preserved LV ejection fraction (LVEF) after congestive heart failure (HF) admission.

Methods

We studied 123 consecutive patients (age 70 ± 15 years, 55% male) who had been hospitalized due to congestive HF with preserved LVEF (&gt; 50%). The exclusion criteria were atrial fibrillation and inadequate echo image quality for strain analyses. The patients underwent speckle-tracking echocardiography and measurement of plasma NT-ProBNP levels on the same day at the time of hospital admission as well as in the stable condition after discharge. Differences in GLS, LVEF and NT-ProBNP (delta GLS, LVEF and NT-ProBNP ; 2nd – 1st measurements) were calculated. The study end points were all-cause mortality and cardiac events.

Results

Mean periods of echo performance after hospitalization were 2 ±１days (1st echo) and 240 ± 289 days (2nd echo), respectively. During the follow-up (974 ± 626 days), 12 patients died and 25 patients were hospitalized because of HF worsening. In multivariate analysis, delta GLS and follow-up GLS were prognostic factors, whereas baseline and follow-up LVEF, NT-ProBNP, changes in LVEF and NT-ProBNP could not predict cardiac events. Delta GLS (p = 0.002) turned out to be the best independent prognosticator. Receiver operating characteristics analysis revealed that -0.6% of delta GLS was the optimal cut-off value to predict cardiac events and mortality (sensitivity 76%, specificity 67%, AUC 0.75). Kaplan-Meier analysis showed that patients with delta GLS more than -0.6% experienced significantly less cardiac events during the follow-up period (p &lt; 0.0001, log-rank).

Conclusion

A change in LV GLS after congestive HF admission was a predictor of the prognosis in patients with preserved LVEF. It would be useful to check the changes in GLS in those with preserved LVEF after discharge.

Tumor mutation burden and immunological, genomic, and clinicopathological factors as biomarkers for checkpoint inhibitor treatment of patients with non-small-cell lung cancer

Cancer treatment using immune checkpoint inhibitors is widely used, although biomarkers predictive of response are not well established. However, both the expressions of programmed cell death ligand 1 (PD-L1) and the tumor mutation burden (TMB) hold promise as such biomarkers for immune checkpoint inhibitors; however, its characteristics and clinical and immunological impacts have not been fully analyzed. We, therefore, evaluated the clinical and immunological parameters related to TMB to identify potential new biomarkers. We enrolled 92 patients with non-small-cell lung cancer who underwent surgery at Fukushima Medical University Hospital from 2013 to 2016. TMB of individual tumors was calculated by whole-exome sequencing analysis. Major cancer-related gene mutations were evaluated using panel sequencing. Expression of PD-L1 and abundance of tumor-infiltrating lymphocytes were evaluated by immunohistochemistry using surgical samples. The median TMB value was 60. TMB was significantly higher in men, current or former smokers, and in patients with squamous cell carcinoma, tumor size ≥ 2.8 cm, wild-type EGFR, TP53 gene mutation-positive status, and cyclin-dependent kinase-inhibitor gene 2A mutation-positive status. According to multivariate analysis, TMB was significantly associated with EGFR gene mutation-negative status (p = 0.0111) and TP53 gene mutation-positive status (p = 0.0425). If TMB is identified as a robust biomarker for immune checkpoint inhibitor administration, analysis of TP53 and EGFR mutations may provide a relatively rapid and easy proxy for predicting TMB.

Large Variation of Dirac Semimetal State in Perovskite CaIrO_{3} with Pressure-Tuning of Electron Correlation

The impact of electron correlation on the Dirac semimetal state is investigated for perovskite CaIrO_{3} in terms of the magnetotransport properties under varying pressures. The reduction of electron correlation with a pressure of 1 GPa enhances the Fermi velocity as much as 40%, but it reduces the mobility by an order of magnitude by detuning the Dirac node from the Fermi energy. Moreover, the giant magnetoresistance at the quantum limit due to the one-dimensional confinement of Dirac electrons is critically suppressed under pressure. These results indicate that the electron correlation is a crucial knob for controlling the transport of a correlated Dirac semimetal.

Revisiting the photoabsorption spectrum of NH3 in the 5.4-10.8 eV energy region

We present a comprehensive revisited experimental high-resolution vacuum ultraviolet (VUV) photoabsorption spectrum of ammonia, NH₃, covering for the first time the full 5.4-10.8 eV energy-range, with absolute cross sections determined. The calculations on the vertical excitation energies and oscillator strengths were performed using the equation-of-motion coupled cluster method restricted to single and double excitation levels and used to help reanalyze the observed Rydberg structures in the photoabsorption spectrum. The VUV spectrum reveals several new features that are not previously reported in the literature, with particular reference to the vibrational progressions of the (D̃¹E^'←X̃¹A₁ ^'), the (F̃¹E^'←X̃¹A₁ ^'), and the (G̃¹A₂ ^″←X̃¹A₁ ^') absorption bands. In addition, new Rydberg members have been identified in nda₁ ^'←1a₂ ^″D̃^''1A₂ ^″←X̃¹A₁ ^', where n > 3 has not been reported before as well as in nde^″←1a₂ ^″F̃¹E^'←X̃¹A₁ ^' and in nsa₁ ^'←1a₂ ^″G̃¹A₂ ^″←X̃¹A₁ ^'. The measured absolute photoabsorption cross sections have been used to calculate the photolysis lifetime of ammonia in the Earth's atmosphere (0-50 km).

P3578Determinants of visual-functional mismatches as assessed by coronary angiography and 3-D angiography-based quantitative flow ratio

Background

Quantitative flow ratio (QFR) is a novel three-dimensional quantitative coronary angiography (QCA)-based computational index that can estimate fractional flow reserve (FFR) without pharmacologically induced hyperemia or the use of a pressure wire.

Purpose

We aimed to evaluate the determinants of visual-functional mismatches between conventional two-dimensional QCA and QFR.

Methods

A total of 504 de novo intermediate-to-severe lesions from 504 patients with stable angina who underwent angiographical and physiological assessments were analyzed. All lesions were divided into four groups based on the significance of visual (QCA-diameter stenosis [DS] >50% and ≤50%) and functional (QFR <0.80 and ≥0.80) stenosis severity. Patient characteristics, angiographic findings, QFR computations, and physiological indices were compared among the four groups.

Results

Among 504 lesions, 153 lesions (30.4%) showed concordantly negative (DS ≤50% and QFR >0.80) and 170 lesions (33.7%) showed concordantly positive (DS >50% and QFR ≤0.80) visual and functional assessments. Among 181 lesions (35.9%) with discordant results, 75 lesions (14.9%) showed a mismatch (DS >50% and QFR >0.80) and 106 lesions (21.0%) showed a reverse mismatch (DS ≤50% and QFR ≤0.80), respectively. Reverse mismatch was associated with smaller reference diameter (odds ratio [OR] 0.561; P=0.036), greater DS (OR 1.039, P=0.013), lower coronary flow reserve (CFR) (OR 0.571, P<0.001, non-diabetes mellitus (OR 2.141, P=0.013) and lower ejection fraction (OR 0.961, P=0.011). Mismatch was associated with smaller DS (OR 0.914, P<0.001), shorter lesion length (OR 0.894, P=0.001), higher CFR (OR 1,633, P<0.001), and lower estimated glomerular filtration rate (OR, 0.968, P=0.001). Lesion location and the index of microcirculatory resistance was not associated with the prevalence of reverse mismatch or mismatch.

Conclusions

There was a high prevalence of visual-functional mismatches between QCA-DS and QFR, and CFR was an important functional factor of mismatches. Our results suggested the difference between predictors of reported visual-functional mismatches of QCA/FFR and those of QCA/QFR.

P5619Comparison of different resting physiological indices: are diastolic pressure ratio and resting full-cycle ratio equal?

Background

Previous reports showed all diastolic resting indexes tested were virtually identical to the instantaneous wave-free ratio (iFR). Although RFR has been also reported to be diagnostically equivalent to iFR, no comparisons have been reported about the prevalence and characteristics of discordance in diagnosis between diastolic pressure ratio (dPR) and resting full-cycle ratio (RFR).

Purpose

This study sought to determine the coronary pressure characteristics of lesions classified as discordant between dPR and RFR in angiographically intermediate stenoses.

Methods

We recruited 532 patients with 668 intermediate (angiographically stenosis between 30% to 70% severity) coronary lesions undergoing FFR assessment and analyzed DICOM pressure tracings of resting state (dPR and RFR) using a fully automated off-line software algorithm in a blind fashion. Diagnostic performance of dPR and RFR was evaluated using FFR as a reference. Furthermore, we investigated similarity and difference between dPR and RFR.

Results

Median FFR was 0.81 with an interquartile range of 0.74 to 0.87. RFR was highly correlated to dPR (R2=0.94, p<0.001), with a mean bias of 0.012 (95% limits of agreement −0.008 to 0.031). The diagnostic performance of RFR versus dPR was diagnostic accuracy 95.4%, sensitivity 100.0%, specificity 91.6%, positive predictive value 90.6%, negative predictive value 100.0%). Using the binary cut-off of dPR ≤0.89 as a cut-off value, RFR showed near identical agreement according to ROC curve analysis (AUC: 0.996, 95% CI: 0.994–0.999, p<0.001). Although dPR and RFR demonstrated equivalent performance against FFR ≤0.8 (79.5% vs. 79.3% accuracy; p=0.960; area under the receiver-operating characteristic curve: 0.869 vs. 0.870; p=0.528), RFR disagreed with dPR in 4.6% (31 of 668). When all lesions (668 vessels) were divided into groups according to the concordance and discordance between dPR and RFR: RFR+/dPR+ (298 vessels, n=240), RFR+/dPR– (31 vessels, n=31 patients), RFR-/dPR- (339 vessels, n=259). There was no lesion showing RFR-/dPR+. The prevalence of ischemia was tended to be higher in lesions evaluated by RFR (49.3% vs 44.6%, P=0.100) when using FFR ≤0.80 as a reference standard. An overall significant difference in the prevalence of FFR ≤0.80 and the FFR values were detected among these 3 groups. Furthermore, pairwise comparison also revealed the prevalence of FFR >0.80 and the FFR values were significantly lower in RFR+/dPR– than in RFR-/dPR-, and significantly higher in RFR+/dPR– than in RFR+/dPR+. (P<0.001 and P<0.001, respectively)

Conclusion

Significant difference in FFR values was observed according to dPR/RFR agreement and disagreement. Revascularization decision making might defer according to the resting index used. Compared with RFR, lesions might be more frequently deferred when dPR was used to assess physiological significance.

Acknowledgement/Funding

None

P2704The association between global coronary flow reserve and coronary inflammation assessed by attenuation index on computed tomography in patients with stable angina pectoris

Background

Impaired global coronary flow reserve (G-CFR) is known to predict worse outcomes in patients with coronary artery disease. Phase contrast cine-magnetic resonance imaging (PC-CMR) of the coronary sinus (CS) is a promising approach for quantifying coronary sinus flow (CSF) and G-CFR without the need for ionizing radiation, radioactive tracers, or intravascular catheterization. Although G-CFR impairment is previously reported to be linked with endothelium dysfunction and progression of atherosclerosis, the association of perivascular adipose tissue inflammation with myocardial coronary flow remains to be determined.

Purpose

We evaluated the association between G-CFR by quantifying CSF using PC-CMR and the extent of coronary inflammation evaluated by perivascular adipose tissue inflammatory status using CT to assess if coronary inflammation is linked with G-CFR in patients with stable angina pectoris (SAP) treated with elective percutaneous coronary intervention (PCI).

Methods

The study enrolled 74 SAP patients with single denovo lesion who underwent coronary CT angiography and PC-CMR within 90 days before coronary intervention. Proximal 40-mm segments of all three major epicardial coronary vessels were traced and examined. Coronary inflammation was assessed by the CT fat attenuation index of perivascular adipose tissue (FAI-PVAT) defined as the mean attenuation of the perivascular adipose tissue (−190 to −30 Hounsfield units (HU)) in a layer of tissue within a radial distance from the outer coronary artery wall equal to the diameter of the vessel. CMR images were also acquired to assess absolute CSF at rest and during maximum hyperemia before elective PCI. The patients were divided into 4 groups according to the number of inflamed vessels as defined by showing FAI ≥−70.1 HU.

Results

In the final analysis of 69 patients (mean age 67, Male 45 (65.2%)), 18, 19, 20, 12 patients exhibited none, 1, 2, 3 inflamed vessels with FAI ≥−70.1 HU, respectively. Rest and maximal hyperemic CSF and corrected G-CFR were 1.28 [0.76,1.55] vs 1.47 [1.11, 1.81] vs 1.30 [0.94, 1.64] vs 1.27 [1.11, 2.00] ml/min/g; P=0.49, 3.50 [2.84, 5.25] vs 3.28 [2.62, 4.31] vs 3.11 [2.16, 3.63] vs 2.37 [1.40, 2.98] ml/min/g; P=0.049, 3.57 [2.17, 4.54] vs 2.25 [1.73, 3.49] vs 2.26 [1.64, 3.38] vs 1.89 [0.89, 2.32]; P=0.023, respectively. G-CFR and hyperemic CSF were both significantly lower in the group with larger number of inflamed vessels.

Conclusions

In SAP patients with significant coronary artery stenosis, G-CFR obtained by PC-CMR significantly associated with the prevalence of inflamed vessels detected by coronary CT. The extent of coronary inflammation may influence global coronary endothelium dysfunction, resulting in decreased G-CFR.

P1782Synchrotron-based 4D-X-ray Phase Tomography of fresh chordae tendineae of mitral valve

Background

Mechanical properties of chordae tendineae of mitral valve (MV) are still not fully investigated. Synchrotron-based X-ray phase tomography (XPCT) is a powerful tool to measure biological soft tissues. Recently, we have developed dynamic X-ray phase tomography (4D-XPCT) to discuss the dynamic phenomena of biological samples quantitatively and applied to chordae tendineae of MV (MVCT).

Purpose

This study evaluated 4-dimensional changes of MVCT and clarified structural changes of MVCT during cardiac cycles.

Methods

The X-ray energy for 4D XPCT was set to 20keV. The effective pixel size was 7.8μm. Fresh MVCT extracted from a pig heart were measured in the specially designed container filled with normal cold saline. MVCT installed on the sample stage was stretched and released with a continuous oscillation of 0.5Hz during a phase tomographic measurement. The amount of stretch was 400μm where a mechanical load caused by stretching was approximately 1N. In this measurement, projection images were acquired with a frame rate of 20Hz during a single sawtooth wave. Therefore, apparent frame rate of 20Hz is expected in 4D phase tomography. Cross section was determined by simple thresholding based on the density. In this case, the threshold was set to 1.018g/cm3.

Results

X-ray phase tomographic images of MVCT at the released (A) and stretched (B) conditions are shown in Fig. 1a. The load applied to the sample and change of the cross section obtained from tomography during stretching and releasing are shown in Fig. 1b and 1c, respectively. The diameter of chordae tendinea were changed approximately 2.5% during stretching and returned to initial diameter during releasing.

Figure 1

Conclusions

This result demonstrated that the 4D-XPCT had a capability to trace the detail of deformation process in the biological soft tissues during continuous oscillation. Even chordae tendinea are mainly consisted of collagen fibers, diameter of the chordae was changed according to stretching and releasing.

P5617Repeatability of instantaneous wave-free ratio in comparison with fractional flow reserve

Background

Instantaneous wave-free ratio (iFR) has been recently introduced as an adenosine free alternative for fractional flow reserve (FFR) to assess the functional significance of epicardial coronary stenosis. Little is known, however, regarding the repeatability and stability of iFR in comparison with FFR.

Purpose

The aim of this study was to evaluate the repeatability of iFR and compare it to that of FFR.

Methods

Patients with stable coronary artery disease who underwent physiological assessment twice within 90 days were enrolled. Repeated measurements were performed at diagnostic and therapeutic catheterization in about 70% of studied population. The remaining patients were measured twice for non-culprit lesion assessment at primary PCI and subsequent non-culprit and ischemia-documented lesion PCI. The calculation of iFRmatlab from DICOM pressure tracing data of resting state was performed using a fully automated off-line software algorithm in a blind fashion. FFR values were also measured by a fully automated algorithm in the same core laboratory by using hyperemic pressure tracing data. The repeatability of the two indices were evaluated and compared. The inter-rater agreement between iFRmatlab and FFR values of two measurements was assessed by κ coefficient. The pressure rate product during each assessment was also documented and evaluated.

Results

Ninety-three lesions from 92 patients were included in the study. The time interval between the two assessments was 38.4±19.0 days. iFRmatlab and FFR both showed significant correlation within the two assessments (iFRmatlab: r=0.75, 95% confidence interval, 0.64 to 0.83; mean difference, −0.006 [−0.18 to −0.01], FFR: r=0.86, 95% confidence interval, 0.79 to 0.90; mean difference, 0.004 [−0.07 to 0.03]). The inter-rater agreement of functional ischemia for iFRmatlab and FFR were κ=0.449 and κ=0.732, respectively. Although the prevalence of functional ischemia during the first and second assessment were consistent for both indices (iFRmatlab: 70.0%/67.7%, FFR: 86.0%/ 86.0%), significant difference was observed in the prevalence of clinical disagreement on the diagnosis of functional ischemia (FFR=0.80, iFR=0.89 used as cut-off values, respectively) between the first and second assessment among the two indices (iFRmatlab: 6.5%, FFR: 23.7%, p=0.002). iFRmatlab was significantly associated with pressure rate product during the examination compared to FFR (iFRmatlab: r= −0.25, 95% confidence interval, −0.43 to −0.04, P=0.018, FFR: r=−0.08, 95% confidence interval, −0.28 to −0.13, p=0.467).

Conclusion

Our results suggested that iFRmatlab showed lower repeatability and reliability for decision making compared to FFR. The instability of iFRmatlab potentially derives at least in part from its association with heart rate and blood pressure product.

P5618Coronary flow capacity to identify stenosis associated with coronary flow improvement after coronary revascularization

Background

Coronary flow capacity (CFC) has recently been introduced as a comprehensive assessment of the coronary circulation by combining coronary flow reserve (CFR) and maximal coronary flow velocity to overcome the limitations of using CFR alone, and was reported to provide enhanced risk stratification compared with CFR. However, its potential to identify stenosis that would be associated with clinically relevant flow coronary flow improvement after revascularization has not been investigated.

Aims

The aim of this study is to quantify coronary flow changes after revascularization in relation to CFC and CFR.

Methods and results

Using a combined dataset of DEFINE FLOW and the Amsterdam UMC prospective ComboWire database, a total of 133 patients (135 vessels) with intermediate coronary artery lesions who underwent intracoronary physiologic assessment including intracoronary Doppler flow measurement before and after PCI were analyzed. The median values of fractional flow reserve (FFR) and CFR before PCI were 0.70 (Q1–3: 0.56–0.80) and 1.64 (Q1–3: 1.30–2.06). The number of lesions classified by CFC before PCI were 14 for normal CFC, 40 for mildly reduced CFC, 33 for moderately reduced CFC and 48 for severely reduced CFC. The lesions with larger impairment of CFC showed greater increase in coronary flow, and vice versa (median percent increase in coronary flow by revascularization: 4.2% for normal CFC; 25.9% for mildly reduced; 50.1% for moderately reduced; 145.5% for severely reduced, P<0.0001). Using the same CFR distribution based on CFC criteria showed that only lesions with severely reduced CFR showed a significantly higher coronary flow increase after PCI (−2.6% for CFR in the normal zone; 26.6% for CFR in the mildly reduced zone; 33.3% for CFR in the moderately reduced zone; 81.7% for CFR in the severely reduced zone, P=0.0007). Compared with the established CFR cut-off value of 2.0, moderate to severely reduced CFC showed higher specificity and positive predictive value (PPV) to predict at least 20% increase in coronary flow after PCI (specificity and PPV: 86.4% and 72.5% for ischemic CFC vs. 75.8% and 40% for CFR cut-off value 2.0). Multivariate logistic regression analysis revealed that the lesions with moderately or severely reduced CFC (odd ratio [OR] = 7.606 95%interconfidence interval [CI]: 2.834–20.412, P<0.001) and pre-PCI FFR (OR=0.0002, 95% CI: 0.0002–0.0204, P<0.001) were the independent predictors of coronary flow increase after PCI.

Conclusion

CFC showed a higher diagnostic efficiency for identification of lesions which benefit from revascularization compared to CFR with respect to coronary flow improvement. This study provides the physiological rational of revascularization for the lesions with moderately to severely reduced CFC from the perspective of coronary flow increase.

Acknowledgement/Funding

Philips Volcano

P6171Role of myocardial mass for identifying FFR-verified ischemia and determining therapeutic strategy

Background

Conventional noninvasive approach using coronary CT angiography (CTA) focusing on only coronary artery lesions remains mismatch in identifying functional ischemia and determining indication for coronary revascularization.

Purpose

We aimed to assess the usefulness of CT-verified myocardial mass for identifying FFR-verified myocardial ischemia and determining the indication of coronary revascularization after FFR examination.

Methods

We examined 244 vessels with intermediate stenoses (50 to 90% stenosis visually on CTA) in 216 patients (mean age 69.2±9.2, 166 men) who underwent both coronary CTA and invasive FFR. In addition to coronary stenosis severity and plaque characteristics on visual, minimal lumen diameter (MLD), minimal lumen area (MLA), plaque volume, the entire myocardial volume of the target vessel (MTV) and that exposed to ischemia (FFR ≤0.80) (myocardial volume of ischemia: MVI) were evaluated. Additionally, therapeutic strategy after FFR was recorded.

Results

Of 244 vessels, myocardial ischemia (FFR ≤0.80) was shown in 99 (40.6%). MTV was larger in the patients with FFR-verified ischemia than those without (53.3±19.2 vs. 41.5±21.6, P<0.001); MLA, plaque burden (PB) and percentage of aggregated plaque volume (%APV) were also associated with ischemia. The area under the curves (AUCs) of MLA, PB, %APV, and MTV were 0.69, 0.67, 0.64, and 0.71, respectively. Addition of MTV to a model with coronary stenosis on visual, MLA, PB, and %APV improved C-index (from 0.72 to 0.79, P<0.01), net reclassification improvement (NRI) (0.71, P<0.01), and integrated discrimination improvement (IDI) (0.10, P<0.01). Of 99 vessels with FFR ≤0.80, MVI was larger in the vessels with early revascularization after FFR than those without (38.8 vs. 29.1, P=0.01).

Conclusions

The measurement of myocardial mass improves the diagnostic performance of coronary CTA for the identification of coronary arteries with FFR-verified ischemia. Furthermore, it is associated with therapeutic strategy for the diseased vessels after FFR examination.

P2703Impact of subtended myocardial mass on the assessment of functional ischemia as evaluated by FFR and QFR

Background

The fractional flow reserve (FFR) becomes a standard practice for revascularization decision-making in evaluating the functional significance of angiographically intermediate epicardial coronary stenosis. The quantitative flow ratio (QFR) is a novel method for rapid computational estimation of FFR without pressure wire and hyperemic induction. FFR has been reported to be associated with not only epicardial stenosis but also subtended myocardial mass (Vsub). In contrast, the relationship between QFR and Vsub has not been clarified.

Purpose

We sought to examine if subtended myocardial mass (Vsub) assessed by coronary computed tomography showed a significant relationship with QFR in comparison with FFR.

Methods and results

We performed a post-hoc analysis of 152 territories (LAD 116, RCA 25 and LCX 11 lesions) with angiographically intermediate-to-severe stenosis in 152 patients who underwent FFR assessment. The median FFR and QFR values were 0.76 (0.64–0.84) and 0.76 (0.72–0.83), respectively. The median diameter stenosis (%DS) and minimum lumen diameter (MLD) were 54.5 (43.9–64.2) and 1.2 (0.9–1.6), respectively. In total, 123 (80.9%) and 29 (19.1%) lesions showed concordant and discordant FFR and QFR functional classifications, respectively. The ability of Vsub/MLD2 to discriminate lesions with FFR≤0.80 and QFR≤0.80 was assessed compared with QCA data. FFR values were associated with Vsub (R=0.37, P<0.001). In contrast, a trend albeit no significant linear relationshipwas detected between QFR and Vsub (R=0.15, P=0.060). The area under the curve (AUC) of Vsub/MLD2 predicting FFR≤0.80 (0.88: 95% confidence interval [CI], 0.83–0.94)was significantly better than that of MLD (0.80: 95% [CI], 0.72–0.88) (P<0.001). On the other hand, the AUC of Vsub/MLD2 predicting QFR≤0.80 (0.82: 95% [CI], 0.75–0.90) was similar to that of MLD (0.80: 95% [CI], 0.72–0.87) (P=0.276). Multivariate analysis showed that the value of Vsub/MLD2 was an independent predictor of FFR≤0.80 (odds ratio [OR]: 1.09, 95% [CI]: 1.03–1.15, P=0.002), whereas it was not an independent predictor of QFR≤0.80.

Conclusions

Subtended cardiac mass volume derived from CT segmentation improved the diagnostic performance of angiography-derived parameters to identify ischemia-producing lesions when FFR used as a reference standard, whereas QFR showed non-significant relationship with subtended cardiac mass.

6113Gender differences in long-term outcomes in patients with deferred revascularization following fractional flow reserve assessment: international collaboration registry of physiologic evaluation

Background

Studies of sex differences in fractional flow reserve (FFR) measurements have shown that in comparison with men, angiographic lesions of similar visual severity are less likely to be ischemia producing in women. Gender specific differences may influence revascularization decision making and prognosis after deferred revascularization following FFR measurement.

Purpose

This study sought to investigate the gender difference in long-term prognosis of patients of deferred revascularization following FFR assessment.

Methods

A total of 879 patients (879 vessels) with deferred revascularization with FFR >0.75 who underwent FFR and CFR measurements were enrolled from 3 countries (Korea, Japan, and Spain). Long-term outcomes were assessed in 649 men and 230 women by the patient-oriented composite outcome (POCO, a composite of any death, any myocardial infarction [MI], and any revascularization). We applied inverse-probability weighting (IPW) based on propensity scores to account for differences at baseline between women and men (age, hypertension, hyperlipidemia, diabetes mellitus, lesion location, clinical status, FFR, Reference diameter, Diameter stenosis, lesion length). The median follow-up duration was 1855 days (745–1855 days).

Results

Median FFR values were 0.88 (0.83–0.93) in men and 0.89 (0.85–0.94) in women, respectively. The occurrences of POCO were significantly high in men compared with that in women (10.5% vs 4.2%, P=0.007). Kaplan–Meier analysis revealed that women had a significantly lower risk of POCO (χ2=7.2, P=0.007). Multivariate COX regression analysis revealed that age, male, diabetes mellitus, diameter stenosis, lesion length, and coronary flow reserve were independent predictors of POCO. After applying IPW, the hazard ratio of male for POCO was 2.20 (95% confidence interval: 1.12 to 4.33, P=0.023).

Conclusion

This large multinational study reveals that long-term outcome differs between women and men in favour of women after FFR-guided revascularization deferral.

Acknowledgement/Funding

None