Cardiovascular risk factors and underlying pathology and prevalence of lipid plaques in women with acute coronary syndromes in different age groups

Background

An incidence of cardiovascular events increases with age in women. The relationship between cardiovascular risk factors, and the underlying pathology and the prevalence of lipid plaques has not been systematically studied in different age groups in women presented with acute coronary syndromes (ACS).

Purpose

We investigated the underlying pathology and the prevalence of lipid plaques in culprit lesions by optical coherence tomography (OCT) in women with different risk factors.

Methods

A total of 382 women who underwent pre-intervention OCT imaging were included. The underlying pathology and the prevalence of lipid plaques in the culprit lesion was compared between women with and without cardiovascular risk factors (i.e. hypertension, smoking, hyperlipidemia, diabetes mellitus, family history and chronic kidney disease) in three different age groups (<60 yr, 60–70 yr, >70 yr).

Results

The relative prevalence of plaque erosion was higher in younger women (<60 yr) and decreased with age (from 51% to 28%, p<0.001). There was no significant difference in the prevalence of lipid plaques between women with and without risk factors, except a higher prevalence of lipid plaques in current smokers compared to non-smokers (79% vs. 63%, p=0.003). In women with hyperlipidemia, the prevalence of lipid plaques was modest in young ages (<60 yr), but increased steeply with age (p<0.001). The increasing age trend for lipid plaque was also observed in women with hypertension (p=0.03) and current smokers (p=0.01). In women with diabetes mellitus and family history, the prevalence of lipid plaques was high even in young ages (<60 yr) and did not increase with age.

Conclusion

The prevalence of plaque erosion was higher in younger women (<60 yr) and decreased with age. Current smokers had significantly higher prevalence of lipid plaque. Patients with diabetes and positive family history had a higher prevalence of lipid plaque at young age. The prevalence of lipid plaques increased with age particularly in women with hyperlipidemia and hypertension.

Funding Acknowledgement

Type of funding sources: Foundation.

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 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.

Contribution of dental health in cardiovascular secondary prevention

Backgrounds

Previous studies have suggested that periodontitis is associated with cardiovascular disease (CVD), partly through exaggerated systematic inflammation through pathogens breaking into the bloodstream and their metabolic products. However, the clinical evidence in the cardiovascular secondary prevention is limited. In addition, there is a paucity of data about the contribution of comprehensively assessed dental health, including dental caries or teeth loss, to CVD incidence. Consequently, current ESC guideline for CVD prevention just briefly refers the contribution of dental health [1].

Objective

To investigate the associations between teeth loss, periodontitis, and dental caries and incident major adverse cardiovascular events (MACE) in patients with existing CVD.

Methods

Patients with known CVD who were admitted to the Department of Cardiology between May 2012 and August 2015 were prospectively, consecutively enrolled. Patients underwent comprehensive dental examinations, including counts of lost teeth, dental caries, and periodontal measurements of clinical attachment loss (CAL), periodontal probing pocket depth (PPD), and bleeding on probing (BOP) by trained periodontists during the hospital stay. We assessed the associations between these dental measures and MACE, defined as a composite of cardiac death, acute myocardial infarction, stroke, and hospital re-admission for worsened congestive heart failure, using multivariate COX proportional hazard models and restricted mean survival time (RMST) analyses. P-values were adjusted by Bonferroni methods.

Results

Among 888 patients included for the present analyses, the mean age was 63.9 (SD: 13.1) years and there were 242 (27.3%) women. During a median follow-up of 4.6 (IQR: 1.4, 6.7) years, incident MACE was confirmed in 142 patients. In multivariate COX proportional hazard models, one more tooth loss was associated with 3 (95% CI: 1, 5) % higher hazard of MACE (adjusted p=0.020). Kaplan-Meier curves showing survival from MACE according to the quartiles of teeth loss were described in Figure 1. Compared with patients with 0 to ≤4 lost teeth, periods free from MACE (95% CI) by 5-years of follow-up were on average shorter by 0.17 (−0.04, 0.37) years, 0.26 (0.04, 0.49) years, and 0.59 (0.34, 0.85) years in patients with 5 to ≤7, 8 to ≤13, and >13 lost teeth, respectively. The RMST differences with varied cutoff years were shown in Figure 2. There were no significant associations between the number of dental caries, CAL, PPD, and BOP and MACE incidence.

Conclusion

In hospitalized patients due to existing cardiovascular diseases, total number of lost teeth was associated with incident MACE. Given that teeth loss is an ultimate consequence of periodontitis or dental caries, the present findings imply that efforts to prevent losing teeth by maintaining dental health would be effective measures for cardiovascular secondary prevention.

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.

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.

Prevalence and culprit lesion plaque characteristics on optical coherence tomography in patients with non-st-segment elevation acute coronary syndrome with zero coronary calcification on coronary CTA

Background

CAC evaluated by non-contrast computed tomography is a marker of atherosclerosis. However, the characteristic features of CCTA and optical coherence tomography (OCT) of culprit lesions in patients with NSTE-ACS showing zero CAC remain unknown.

Objectives

This study aimed to assess the prevalence and characteristic features of culprit lesions on coronary CT angiography (CCTA) and optical coherence tomography (OCT) in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) showing zero coronary artery calcium (CAC).

Methods

A total of 176 consecutive patients with NSTE-ACS who underwent preprocedural CCTA and OCT were studied. Patients were divided into two groups according to their CAC (zero-CAC and non-zero-CAC groups). Baseline characteristics, CCTA and OCT findings were compared between these two groups.

Results

The prevalence of patients with zero-CACS was 15.9% (28/176). Patients in zero CAC group were younger (mean age, 55 vs. 65 years, P<0.001) and had a lower prevalence of diabetes (10.7 vs 37.2%, P=0.012) than non-zero CAC group. In zero CAC group, the lower prevalence of napkin ring sign (3.5% vs. 28.4%, P=0.028), smaller LV mass index (77.7 vs. 83.9, P=0.04), lower prevalence on spotty calcification (0 vs. 83.8%, P<0.001), lower epicardial fat volume (111.3 vs. 142.6 cm3, P=0.025), and lower pericoronary adipose tissue attenuation (−71.5 vs. −70.2 HU, P=0.07) on CCTA were observed. On OCT, the frequency of plaque erosion (82.1 vs. 44.6%, P<0.001) was significantly higher in zero-CACS group. The prevalence of lipid-rich plaque (46.4 vs. 86.5%, P<0.001), thin-cap fibroatheroma (17.9 vs. 46%, P=0.006), macrophage accumulation (46.4 vs. 81.8%, P<0.001) and cholesterol crystal (7 vs. 41.9%, P<0.001) were all significantly lower in zero-CAC group.

Conclusions

Zero CAC NSTE-ACS was not rare. Zero-CAC NSTE-ACS was characterized by specific phenotypes defined by the combined assessment of CCTA and OCT. Further studies are warranted if these characteristics of NSTE-ACS on preprocedural imaging studies provide prognostic information or guidance of a specific therapeutic approach.

Funding Acknowledgement

Type of funding sources: None.

Level of vascular inflammation is higher in acute coronary syndromes compared to chronic coronary disease

Background

Vascular inflammation has been recognized as one of the key factors in the pathogenesis of acute coronary syndromes (ACS). Peri-coronary adipose tissue (PCAT) attenuation by computed tomography angiography (CTA) has emerged as a marker specific for coronary artery inflammation. We examined the relationship between clinical presentation and coronary artery inflammation assessed by PCAT attenuation and coronary plaque characteristics.

Methods

Patients with ACS or stable angina pectoris (SAP) who underwent pre-intervention coronary CTA and optical coherence tomography (OCT) were enrolled. PCAT attenuation was measured around the culprit lesion and in the proximal 40 mm of all coronary arteries. PCAT attenuation and OCT findings were compared between patients with ACS versus SAP.

Results

Among 471 patients (ACS: 198, SAP: 273), PCAT attenuation was higher in ACS patients than in SAP patients both at the culprit plaque level (−67.5±9.6 Hounsfield unit [HU] vs. −71.5±11.0 HU, p<0.001) and the culprit vessel level (−68.3±7.7 HU vs. −71.1±7.9 HU, p<0.001). The mean PCAT attenuation of all 3 coronary arteries was also significantly higher in ACS patients than in SAP patients (−68.8±6.3 HU vs. −70.5±7.1 HU, p=0.007). After adjusting patient characteristics, not only thin-cap fibroatheroma (OR: 2.44; 95% CI: 1.63–3.65) and macrophages (OR: 2.07; 95% CI: 1.34–3.21) but also PCAT attenuation in the culprit plaque (OR: 1.04; 95% CI: 1.02–1.06) was associated with the clinical presentation of ACS.

Conclusions

PCAT attenuation at culprit plaque, culprit vessel, and pan-coronary levels was higher in ACS patients than in SAP patients. Vascular inflammation appears to play a crucial role in the development of ACS.

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.

Optical coherence tomography

Optical coherence tomography (OCT) is a non-contact method for imaging the topological and internal microstructure of samples in three dimensions. OCT can be configured as a conventional microscope, as an ophthalmic scanner, or using endoscopes and small diameter catheters for accessing internal biological organs. In this Primer, we describe the principles underpinning the different instrument configurations that are tailored to distinct imaging applications and explain the origin of signal, based on light scattering and propagation. Although OCT has been used for imaging inanimate objects, we focus our discussion on biological and medical imaging. We examine the signal processing methods and algorithms that make OCT exquisitely sensitive to reflections as weak as just a few photons and that reveal functional information in addition to structure. Image processing, display and interpretation, which are all critical for effective biomedical imaging, are discussed in the context of specific applications. Finally, we consider image artifacts and limitations that commonly arise and reflect on future advances and opportunities.

Direct comparison of bioabsorbable and biodurable polymer everolimus-eluting stent in neointimal stent coverage and in-stent thrombus using high-resolution angioscope

Background/Introduction

Although second-generation drug eluting stent (DES) employing biodurable polymer drastically shortened the duration of dual antiplatelet therapy (DAPT), previous reports raised concerns that switching from DAPT to single antiplatelet therapy increased rates of subsequent stent thrombosis with time. Third-generation DES employing bioabsorbable polymer has been introduced so as not to hinder the healing process of the vessel wall, however, at present, both DES with bioabsorbable polymer and those with biodurable polymer are used in parallel. It means there is no conclusive evidence regarding pros and cons of these two types of polymers.

Purpose

This study aims to clarify how bioabsorbable polymer and biodurable polymer act on the human coronary artery by observing neointimal stent coverage (NIC) and in-stent thrombus by comparing the third-generation DES with bioabsorbable-polymer cobalt-platinum everolimus-eluting stent (BP CoPt-EES), and the second-generation DES with biodurable-polymer cobalt-chromium everolimus-eluting stent (DP CoCr-EES).

Methods

This is a multicenter observational study including 11 hospitals. We investigated 70 stents (BP CoPt-EES: 40, DP CoCr-EES: 30) of 60 cases, who underwent stent implantation followed by simultaneous observation by coronary angiography, IVUS and angioscopy within 6 to 12 months. For angioscopy, we used a recently available, high-resolution angioscope with a pixel count of 9,000 which realized both stent coverage analysis and planar thrombus detection precisely. Neointimal stent coverage was graded from G0: non coverage to G3: full coverage, and heterogeneity value of neointima was measured as the difference between maximum and minimum NIC grade.

Results

A strong relationship was observed between NIC grade and in-stent thrombus in all stents (p=0.0011), and between the heterogeneity value and stent thrombus (p=0.012). There was no statistical difference in NIC grade between BP CoPt-EES vs. DP CoCr-EES; grade 0: 0 (0.0%) vs. 2 (6.7%), grade 1: 13 (32.5%) vs. 11 (36.7%), grade 2: 6 (15.0%) vs. 6 (20.0%), grade 3: 21 (52.5%) vs. 11 (36.7%), p=0.17) and neither in the heterogeneity value of neointima (p=0.49). The ratio of stent thrombus did not reach statistical difference; 16 (40.0%) in BP CoPt-EES vs. 17 (56.7%) in DP CoCr-EES (p=0.23).

Conclusion

The existence of stent thrombus was associated with the neointimal stent coverage. There was no significant difference both in neointimal stent coverage and stent thrombus between bioabsorbable polymer cobalt-platinum EES and biodurable polymer cobalt-chromium EES after 6 to 12 months following stent deployment.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Boston Scientific JapanOvalis ltd

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.

Comparison of neointimal coverage between biodegradable-polymer everolimus-eluting stent and durable-polymer everolimus-eluting stent using angioscopy for the patients with acute coronary syndrome

Background

New-generation biodegradable-polymer platinum chromium everolimus-eluting stent (BP-PtCr-EES) is available, which has different polymer and alloy compare to more established stent design, a durable-polymer cobalt-chromium everolimus-eluting stent (DP-CoCr-EES).

Purpose

To compare neointimal coverage (NIC) between BP-PtCr-EES and DP-CoCr-EES by using coronary angioscopy (CAS).

Methods

A total of 36 patients (44 stents) with BP-PtCr-EES or DP-CoCr-EES who underwent CAS at 1 year after stenting were investigated. We compared angioscopic findings assessed by angioscopy between BP-PtCr-EES (n=18) and DP-CoCr-EES (n=26). NIC grade and yellow plaque grade (YPG) was adopted from earlier reports from grade 0 to 3. We determined maximum (max-) and minimum (min-) NIC grade and heterogeneity score (HGS = max NIC grade minus min NIC grade). We also assessed YPG and the presence of thrombus (TH).

Results

Six lesions (33.3%) in BP-PtCr-EES group and 7 (26.9%) lesions in DP-CoCr-EES group were culprit lesions of acute coronary syndrome, which did not statistically differ between the two groups (p=0.74). And there were no significant differences in stent diameter (BP-PtCr-EES: 2.97±0.39 mm vs DP-CoCr-EES: 3.14±0.45 mm, p=0.22) and length (BP-PtCr-EES: 26.9±7.9 mm vs DP-CoCr-EES: 28.4±8.0 mm, p=0.54). In terms of CAS findings, BP-PtCr-EES group has better neointimal coverage than DP-CoCr-EES group (max NIC grade: 2.6±0.7 vs 2.0±0.9, p=0.01. min NIC grade: 1.1±0.8 vs 0.5±0.5, p<0.01), but HGS was almost same (1.6±0.7 vs 1.5±0.9, p=0.70). YPG of BP-PtCr-EES group showed significantly lower than DP-CoCr-EES group (1.0±1.0 vs 1.7±1.0, p=0.02). The rate of TH was significantly lower in BP-PtCr-EES group than DP-CoCr-EES group (25%, n=6, vs 75%, n=18, p=0.03). There were no clinical events such as stent thrombosis or restenosis during the observation period in both stent groups.

Conclusion

Superior neointimal coverage and less YPG or TH were observed by CAS in the BP-PtCr-EES group at 1 year after stenting. Clinical significance was still unknown because of no clinical events in both groups. Prospective and large populations studies may be required.

Funding Acknowledgement

Type of funding source: None

Diagnostic value of myocardial perfusion CT 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 coronary artery lesions has been previously reported. However, the diagnostic value of quantitative evaluation of regional absolute coronary flow by CTP to detect microvascular dysfunction remains unknown.

Purpose

The aim of study is to assess the diagnostic value of preprocedural CTP to detect coexisting microvascular dysfunction with functionally significant epicardial stenosis in patients with chronic coronary syndromes.

Methods and results

Thirty-three chronic coronary syndrome patients with de novo single functionally significant stenosis (Fractional flow reserve [FFR]<0.80) who underwent noncomplicated PCI were investigated. In CTP analysis, regional myocardial blood flow (MBF) at rest (rest-MBF) and hyperemia (hyperemic-MBF) were evaluated semi-automatically. Clinical characteristics, pressure-temperature sensor-chipped wire-based information and CTP findings were compared between groups with and without microvascular dysfunction defined by the index of microcirculatory resistance (IMR) (IMR≥25, n=17, IMR<25, n=16, respectively).

The determinants of coexistence of microvascular dysfunction and functional epicardial stenosis were determined. In invasive wire-based analysis, FFR, coronary flow reserve (CFRwire) and IMR were 0.68 (0.57–0.72), 1.61 (1.00–1.98), and 26.7 (19.3–39.4) respectively.

In CTP analysis, rest and hyperemic-MBF and CFR derived from CTP (CFRCTP; calculated as hyperemic-MBF/rest-MBF) were 2.00 (1.31–2.35) ml/min/g, 4.03 (2.11–5.44) ml/min/g, and 2.09 (1.49–2.09) respectively.

In the lesions with IMR>25, hyperemic-MBF was significantly lower than that in IMR<25 (3.42 [1.89–4.34] vs 4.50 [3.44–5.99], p=0.031), although there was no significant difference in regional rest-MBF and CFRCTP (1.75 [1.31–2.24] vs 2.05 [1.35–2.46], p=0.439, and 1.83 [1.21–2.11] vs 2.61 [1.91–2.91], p=0.101 respectively). Receiver operating characteristic curve analysis of hyperemic-MBF detecting IMR>25 showed area under the curve of 0.72 (0.54–0.90), sensitivity of 47% and specificity of 94%.

Conclusion

Quantitative assessment of absolute coronary flow by CTP may help detect coexisting microvascular dysfunction in patients with significant epicardial stenotic lesions.

Funding Acknowledgement

Type of funding source: None

Predictors of rapid plaque progression: an optical coherence tomography study

Background

Two patterns of plaque progression have been described: slow linear progression and rapid step-wise progression. The former will cause stable angina when the narrowing reaches a critical threshold, while the latter may lead to acute coronary syndromes or sudden cardiac death.

Purpose

The aim of the study was to identify morphologic predictors for rapid plaque progression.

Methods

Patients who had OCT imaging during the index procedure and follow-up angiography with a minimum of 6-month interval were selected. Non-culprit lesion was defined as a plaque with a diameter stenosis ≥30% on index angiogram. Lesion progression was defined as the decrease of angiographic minimum lumen diameter ≥0.4 mm at follow-up (mean, 7.1 months). Baseline morphological characteristics of the plaques with rapid progression were evaluated by OCT. In a subgroup with follow-up OCT imaging for plaques with progression, morphological changes from baseline to follow-up were assessed.

Results

Among 517 lesions, 50 lesions showed progression. These lesions had a significantly higher prevalence of lipid-rich plaque (76.0% vs. 50.5%), thin-cap fibroatheroma (TCFA) (20.0% vs. 5.8%), layered plaque (60.0% vs. 34.0%), macrophage accumulation (62.0% vs. 42.4%), microvessel (46.0% vs. 29.1%), plaque rupture (12.0% vs. 4.7%), and thrombus (6.0% vs. 1.1%), compared to those without progression. The multivariable analysis identified lipid-rich plaque [odds ratio (OR) 2.17, 95% confidence interval (CI) 1.02–4.62, p=0.045], TCFA (OR 5.85, 95% CI 2.01–17.03, p=0.001), and layered plaque (OR 2.19, 95% CI 1.03–4.17, p=0.040) as predictors of subsequent lesion progression. In a subgroup with follow-up OCT, a new layer was detected in 14/41 (34.1%) plaques.

Conclusions

Lipid-rich plaque, TCFA, and layered plaque were predictors of subsequent rapid plaque progression. A new layer, a signature of rapid progression through plaque disruption and healing, was detected in 1/3 of the cases.

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 >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 >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<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<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<0.05) and 1.11 (AUC: 0.74, 95% CI: 0.63–0.86, P<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 <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 >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 >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

Circadian variations in pathogenesis of ST-segment elevation myocardial infarction

Background

Previous studies have reported a circadian variation in the onset of ST-segment elevation myocardial infarction (STEMI). However, underlying mechanisms for the circadian variation have not been fully elucidated.

Purpose

We investigated the relationship between onset of STEMI and the underlying pathology using optical coherence tomography (OCT).

Methods

Patients presenting with STEMI were selected from an international, multi-center, longitudinal registry study, which included patients who underwent OCT imaging of the culprit lesion at 11 institutions in 6 countries. Onset of MI was estimated using the time of OCT imaging. Patients were divided into 4 groups based on the estimated time of onset (00:00–05:59, 06:00–11:59, 12:00–17:59, or 18:00–23:59). Underlying pathologies of MI (plaque rupture, plaque erosion, and calcified plaque) were compared among the 4 groups.

Results

Among 648 patients, plaque rupture was diagnosed in 386 patients (59.6%), plaque erosion in 197 patients (30.4%), and calcified plaque in 65 patients (10.0%). A marked circadian variation was detected in the incidence of plaque rupture with a peak at 9:00, whereas it was not evident in plaque erosion or calcified plaque. The probability of plaque rupture increased in the periods of 06:00–11:59 (odds ratio: 2.13, 95% confidence interval: 1.30 to 3.49, p=0.002) and 12:00–17:59 (odds ratio: 2.10, 95% confidence interval: 1.23 to 3.58, p=0.005), compared to the period of 00:00–05:59. This circadian pattern was observed only during weekdays (p=0.013) and it was not evident during the weekend (p=0.742).

Conclusions

Plaque rupture occurred most frequently in the morning and the circadian variation was evident only during the weekdays. Acute MI caused by plaque rupture may be related to catecholamine surge.

Funding Acknowledgement

Type of funding source: None

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.

P2705Hybrid QFR-FFR decision making strategy for revascularization

Background

Measurement of the fractional flow reserve (FFR) has become 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 vasodilator drugs.

Purpose

Nevertheless, the evidence was shown the clinical better outcome of coronary revascularization stratified by FFR, the adoption of FFR remains low. We hypothesized that combined QFR and FFR hybrid strategy could improve the physiological assessment without pressure wire and drugs.

Methods and results

We performed a post-hocanalysis of 549 vessels with angiographically intermediate stenosis in 549 patients who underwent measurement of FFR. The median FFR and QFR values were 0.81 (0.73–0.87) and 0.79 (0.74–0.87), respectively.The ischemic threshold was defined as 0.80 for both QFR and FFR measures. The diagnostic sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the QFR for predicting an FFR of ≤0.80 were 86.2%, 71.9%, 78.9%, 74.5%, and 84.5%, respectively. The area under the receiver operating characteristic curve using the cut-off threshold of ≤0.80 for the FFR was 0.85 (95% confidence interval [CI], 0.81–0.88) for the QFR.In total, 433 (78.9%) and 116 (21.1%) lesions showed concordant and discordant FFR and QFR functional classifications, respectively. A hybrid QFR-FFR strategy was developed, by allowing deferral when QFR values providing negative predictive value greater than 90% and treat others when QFR values greater than that showing 90% positive predictive value, with adenosine being given only to patients with QFR in between those values. For the FFR cut-off (0.8), an QFR of <0.73 could be used to confirm treatment (PPV of 90.7%), while an QFR value of >0.83 could be used to defer revascularization (NPV of 90.0%). When QFR values fall between 0.73 and 0.84, adenosine is given for hyperemic induction and the FFR cut-off of 0.8 is used to guide revascularization. This hybrid QFR-FFR approach has a 95% agreement with an FFR-only decision making, and 285 lesions (51.9%) would have obviated the need of a pressure wire and adenosine.

Hybrid QFR-FFR strategy

Conclusions

A hybrid QFR-FFR strategy for coronary revascularization could reduce the need of a pressure wire and vasodilator drugs, which may increase the penetration of functional assessment of coronary lesions.

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.

P2651Seasonal variations in the pathogenesis of acute coronary syndromes

Background

Seasonal variations in acute coronary syndrome (ACS) has been known with the winter being the peak in incidence and mortality. However, underlying pathophysiology for this variation has not been studied.

Purpose

We sought to compare pathobiology of the culprit lesions assessed by optical coherence tomography (OCT) among the four seasons.

Methods

Patients with ACS who underwent OCT were recruited from 6 countries in the Northern Hemisphere. The prevalence of 3 most common pathologies, plaque rupture, plaque erosion and calcified plaque, and other features of coronary plaques were compared among the four seasons.

Results

In 1113 patients with ACS, 284 (25%) patients were admitted in spring, 243 (22%) patients in summer, 290 (26%) patients in autumn and 296 (27%) patients in winter. The proportion of underlying 3 pathologies was significantly different in each season (prevalence of plaque rupture, plaque erosion, calcified plaque was 50%, 39%, and 11%, respectively in the spring; 44%, 43%, and 13% in the summer; autumn: 49%, 39%, and 12% in the autumn; 57%, 30%, and 13% in the winter; P=0.039). The proportion of plaque rupture was higher in winter but lower in summer, and that of plaque erosion was higher in summer, but lower in winter. Maximum and minimum temperatures on the day of OCT procedure were significantly lower in the plaque rupture group than in the plaque erosion group (P=0.02 and P=0.012, respectively). In the rupture group, the prevalence of hypertension was significantly higher in winter, but in the erosion group, it was not different among the four seasons.

Figure 1. The proportion of culprit lesion characteristics were significantly different among the 4 season groups. (P=0.039) The proportion of plaque rupture was significantly higher in winter but lower in summer. In contrast, the proportion of plaque erosion was higher in summer, but lower in winter.

Conclusions

Seasonal variation of the underlying mechanisms of ACS reflects different pathobiology. The proportion of plaque rupture is highest in winter and the proportion of plaque erosion is highest in summer. A different approach may be needed for the prevention and treatment of ACS depending on the season of its occurrence.

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

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.

P6439Clinical outcomes of acute coronary syndrome with intact-fibrous cap plaque at the culprit lesions in diabetic and non-diabetic patients

Background

Previous studies revealed that the morphological substrates of the culprit lesion assessed by optical coherence tomography (OCT) in acute coronary syndrome (ACS), which includes ruptured plaque (RP) and intact fibrous cap (IFC) plaque, are associated with subsequent clinical outcomes. Nevertheless, the impact of culprit morphology on clinical outcomes has not been evaluated in patients with diabetes mellitus (DM), which is one of the major determinants of clinical prognosis.

Purpose

We sought to investigate the association of the culprit lesion morphology with clinical outcomes in patients with DM and those without DM.

Methods

We retrospectively investigated a total of 508 patients with acute myocardial infarction (AMI) experiencing their first episode of ACS in whom OCT-guided, primary percutaneous coronary intervention (PCI) was performed and a culprit lesion was observed by OCT with sufficient image quality. Patients were divided into two groups according to the culprit lesion morphology into patients with RP (RP group) and those without RP (IFC group). The rate of major adverse cardiac events (MACE) including death, myocardial infarction, target or non-target lesion revascularizations were compared between RP and IFC groups in patients with DM (DM) and those without DM (non-DM), separately.

Results

MACE was captured in 80 patients during the median follow-up of 505 (IQR 274–1300) days. In non-DM, RP group showed significantly worse MACE-free rate than in IFC group (Figure), In DM, there was no significant difference between RP and IFC groups (Figure).

Figure 1

Conclusion

Culprit lesion morphology assessed by OCT was not associated with clinical outcomes in DM patients unlike non-DM patients. Distinct strategy for secondary prevention may be required for DM patients.

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

P2239The association between global coronary flow reserve and coronary inflammation assessed by fat attenuation index on computed tomography in patients with acute coronary syndrome

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 global coronary flow reserve (G-CFR) without the need for ionizing radiation, radioactive tracers, or intravascular catheterization. Although G-CFR impairment has been previously reported to be linked with endothelium dysfunction and subsequent atherosclerosis, the relationship between coronary inflammation and absolute coronary blood flow volume or coronary flow reserve remains elusive.

Purpose

We evaluated the association between G-CFR by quantifying CSF using PC-CMR and the extent of coronary inflammation in patients with ACS treated with emergent percutaneous coronary intervention (PCI).

Methods

The study enrolled 107 ACS patients who underwent uncomplicated emergent PCI within 48 hours of symptom onset and coronary CT angiography were performed before PCI. Proximal 40-mm segments of all three major epicardial coronary vessels were 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, as previously reported. CMR images were acquired to assess absolute CSF at rest and during maximum hyperemia within 30 days after emergent PCI and revascularization of non-culprit significant lesions. The patients were divided into 4 groups according to the number of inflamed vessels (defined as 0, 1, 2, 3 vessels with FAI ≥−70.1 HU).

Results

In the final analysis of 102 patients (mean age 64, Male 65 (63.7%)) including 77 patients with non-ST-segment elevation myocardial infarction (NSTEMI) (75.5%) and 25 patients with unstable angina pectoris (UAP), 25, 30, 26, 21 patients exhibited none, 1, 2, 3 inflamed vessels with FAI ≥−70.1 HU, respectively. Rest and maximal hyperemic CSF and corrected G-CFR were 1.17 [0.63, 1.71] vs 1.36 [1.05, 1.67] vs 1.21 [0.83, 1.94] vs 1.35 [0.96, 1.67] ml/min/g; P=0.61, 3.26 [2.62, 2.99] vs 3.50 [2.60, 4.03] vs 3.34 [1.78, 4.20] vs 2.48 [1.54, 3.43]; P=0.061, 2.95 [2.05, 4.30] vs 2.63 [1.80, 3.56] vs 2.15 [1.37, 2.91] vs 2.18 [1.46, 2.42]; P=0.018, respectively. G-CFR was significantly lower in group with increased number of inflamed vessels.

Conclusions

In ACS patients successfully revascularized within 48 hours of onset, G-CFR obtained by noninvasive PC-CMR significantly associated with the prevalence of inflamed vessels detected by coronary CT. Further large population study is warranted to test the hypothesis that the extent of coronary inflammation before coronary revascularization in patients with ACS might provide prognostic information.

6111Optical coherence tomography derived predictors of restenosis after non-stenting coronary intervention with drug-coated balloon

Background

One of the limitations of metallic stents including contemporary drug eluting stents lies in the permanent existence of metallic materials within the coronary arteries, which may lead to neoatherosclerosis and a long-term use of dual antiplatelet therapy. Some reports have recently suggested the efficacy and safety of non-stent strategy with drug-coated balloon (DCB) angioplasty in combination with debulking devices for de novo lesions. However, little is known about the potential risk of restenosis after percutaneous coronary intervention (PCI) with DCB.

Purpose

We sought to assess the predictive factors of restenosis by optical coherence tomography (OCT) after PCI with DCB instead of metallic stents.

Methods

We retrospectively investigated 49 de novo lesions in 38 patients treated by DCB without stent implantation in whom OCT was performed immediately after PCI and follow-up angiography was performed at median of 5.6 (3.7–6.9) months. OCT findings after PCI and the incidence of restenosis at follow-up angiography were evaluated. By means of OCT images, medial coronary dissection was defined as a dissection which reached the medial layer of the vessel, and major dissection was defined as a dissection with more than 60 degrees of the circumference of the vessel or more than 3mm in length. Restenosis was defined as more than 50% diameter stenosis evaluated by Quantitative Coronary Angiography.

Results

Restenosis was observed in 13 of 49 lesions (27%). In univariate logistic regression analysis, major dissection and medial dissection at the final OCT were associated with restenosis (Odds ratio [OR] 10.0; 95% confidence interval [CI] 2.5–52.6; p<0.01 and OR 5.8; 95% CI 1.5–25.1; p=0.01, respectively). Lesion preparation prior to DCB were performed with rotational atherectomy (n=9), orbital atherectomy (n=2), directional atherectomy (n=4), excimer laser angioplasty (n=17), scoring balloon angioplasty (n=13), or balloon angioplasty (n=4). OCT-defined major dissection remained a significant predictor for restenosis independent of debulking devices used for the preparation (OR 8.1; 95% CI 1.2–70.2; p=0.03).

Conclusions

Major dissection was associated with restenosis after non-stenting PCI with DCB. Stent implantation should be considered in cases of OCT-defined major dissection.

Acknowledgement/Funding

None

P5251Prognostic value of unrecognized myocardial infarction detected by cardiac magnetic resonance imaging in patients presenting with first acute myocardial infarction

Background

Unrecognized myocardial infarction (UMI) has been reported to be strongly associated with worse outcome in patients with cardiovascular disease. Cardiac magnetic resonance (CMR) imaging is a useful instrument for the assessment of pathological and functional conditions.

Purpose

This study sought to evaluate the prognostic value of the presence of unrecognized non-infarct-related late gadolinium enhancement (non-IR LGE) evaluated by cardiac magnetic resonance imaging in patients presenting with a first acute myocardial infarction (AMI).

Methods

We studied 311 AMI patients including 213 STEMI and 98 NSTEMI patients without the history of prior MI who underwent uncomplicated primary or emergent PCI within 48 hours of symptom onset between October, 2012 and June, 2017. CMR images were acquired at 28 [21, 32] days after primary/emergent PCI. UMI was defined as having LGE separately in the different and remote area from the perfused territory by infarct-related artery. In case of multiple LGE areas of infarction, the coronary angiography findings were used to support identification of the area corresponding to the culprit artery of AMI. The association of CMR variables and other clinical characteristics with major adverse cardiac events (cardiac death, nonfatal myocardial infarction, nonfatal stroke) were investigated.

Results

Forty-six patients (14.8%) showed UMI defined by the presence of non-IR LGE (27 STEMI and 19 NSTEMI). During the follow up for 830 [385, 1309] days, cardiovascular death occurred in 7 patients (2.3%), and non-fatal MI and non-fatal stroke occurred in 10 and 1 patients, respectively (3.2%, 0.3%, respectively). There was no significant difference in the prevalence of UMI and incidence of MACE between the patients with STEMI and NSTEMI (p=0.13, p=0.11, respectively). Event-free survival was significantly worse in patients with UMI (log-rank χ2=16.3, P=0.001) in a total cohort. Cox proportional hazards analysis showed that UMI was independent predictors of adverse cardiac events during follow-up in patients with first MI (hazard ratio, 7.60, 95% confidence interval, 2.78–20.8, p=0.0001).

Conclusions

In first AMI patients, UMI defined by non-IR LGE obtained by noninvasive CMR provides significant prognostic information. Early detection of UMI by CMR may help risk stratification of patients with AMI and support adjunctive aggressive patient management such as strong statin therapy and life style intervention.

P6393Differences in coronary inflammation between the culprit and non-culprit vessels assessed by fat attenuation index on computed tomography in patients with acute coronary syndromes

Background

Inflammation is linked with progression of coronary atherosclerosis. Recent studies have reported the association between elevated perivascular fat attenuation index (FAI) on computed tomography (CT) and worse cardiac outcomes in patients with coronary artery disease.

Purpose

We aimed to investigate the differences in FAI-defined peri-coronary inflammation status between the culprit and non-culprit vessels in patients with acute coronary syndromes (ACS).

Methods

A total of 78 ACS patients with left anterior descending coronary arteries (LAD) as a culprit vessel who underwent coronary CT angiography and invasive coronary angiography were studied. Proximal 40-mm segments of the LAD and the right coronary artery (RCA) were traced. Coronary inflammation was assessed by the FAI defined as the mean CT attenuation value of 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. All patients were divided into two groups according to the values of FAI in the LAD: high FAI group (FAI-LAD > median; n=39) and low FAI group (FAI-LAD ≤ median; n=39). Patient characteristics, angiographic and CT findings were compared between the two groups.

Results

In a total of 78 patients, median FAI in the LAD was −70.20 (interquartile range, −74.81 to −64.58) HU. High FAI group was associated with male sex and lower left ventricular ejection fraction compared with Low FAI group. Minimal lumen diameter, reference diameter, diameter stenosis, and lesion length on quantitative coronary angiography analysis and coronary artery calcium score on CT was not different between the groups. FAI in the RCA was also higher in High FAI group than that in Low FAI group (−67.64±8.31 vs. −76.47±6.25 HU, P<0.001). Paired t-test comparison demonstrated that culprit vessel showed higher FAI than the non-culprit vessel (−69.85±7.74 vs. −72.11±8.54 HU, P=0.013).

Conclusions

In ACS patients with culprit LAD lesions, FAI-defined peri-coronary inflammation status is higher in the culprit vessel than in the non-culprit vessel.

P3585Prognostic value of the assessment of coronary sinus flow by phase contrast cine-magnetic resonance imaging in patients with acute coronary syndrome

Background

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 G-CFR by quantifying CSF using PC-CMR in patients with ACS treated with primary or emergent percutaneous coronary intervention (PCI).

Methods

The study prospectively enrolled 387 ACS patients who underwent uncomplicated primary or emergent PCI within 48 hours of symptom onset. Breath-hold PC-CMR images of CS were acquired to assess absolute CSF at rest and during maximum hyperemia within 30 days after primary PCI and revascularization of functionally significant non-culprit lesions of ACS. The association of G-CFR and baseline clinical characteristics with major adverse cardiac events (cardiac death, nonfatal myocardial infarction, late revascularization, or hospitalization for congestive heart failure) was investigated.

Results

In the final analysis of 366 patients (Male 294 (80.3%), mean age 65) including 233 patients (63.7%) with ST-segment elevation myocardial infarction (STEMI) and 133 patients (36.3%) with non-ST-segment elevation acute coronary syndrome (NSTE-ACS), rest and maximal hyperemic CSF and corrected G-CFR were 1.24 [0.83, 1.71] ml/min/g, 2.56 [1.87, 3.66] ml/min/g, and 2.20 [1.53, 3.17], respectively. During a median follow-up of 16 months, MACE occurred in 84 patients (cardiac death: 9, nonfatal myocardial infarction: 11, late revascularization: 59, hospitalization for congestive heart failure: 5). Cardiac event-free survival was significantly worse in patients with a corrected G-CFR <2.00 (log-rank χ2=20.2, P<0.001). Cox proportional hazards analysis showed that corrected G-CFR were independent predictors of adverse cardiac events during follow-up in patients with STEMI (hazard ratio, 0.66, 95% confidence interval, 0.51–0.85, p=0.001) and NSTE-ACS (hazard ratio, 0.64, 95% confidence interval, 0.43–0.95, p=0.026), respectively.

Conclusions

In ACS patients successfully revascularized within 48 hours of onset, G-CFR obtained by noninvasive PC-CMR provided significant prognostic information independent of infarction size and conventional risk scores.

P5622Clinical significance of late-acquired malapposition observed by serial optical coherence tomography after second-generation drug eluting stents

Background

Previous studies have demonstrated that the presence of late-acquired stent malapposition after stent implantation may be a risk of late and very late stent thrombosis and myocardial infarction, which is however still controversial.

Purpose

We sought to investigate the incidence and prognosis of late acquired stent malapposion after second-generation drug eluting stents (2G-DES) implantation.

Methods

A total of 199 lesions in 139 patients who underwent optical coherence tomography (OCT) at both immediately after implantation (Baseline) and 6–12 months after 2G-DES implantation (follow-up) were investigated. We excluded lesions with stent failure before follow-up examination. We evaluated presence or absence of malapposed strut at 1mm interval of OCT images and stents with one or more cross-sections with >30% malapposed strut was defined as stents with malapposition (MP), otherwise well-apposed (WA). We divided the lesions into 4 groups according to the presence of malapposition at baseline and follow-up; WA and WA, persistent well-apposed; MP and WA, resoloved malapposition; WA and MP, late acquired malapposition (LAMP); and MP and MP, persistent malapposition. We compared the target lesion failure (TLF) rate after follow-up examination among 4 groups with Kaplan–Meier analysis.

Results

Median follow-up period was 469 (IQR 71–1416) days. follow-up OCT examination was performed at median 9 months (IQR 7.6–10.5). There were no significant differences in patient's and procedural characteristics among the 4 groups. TLF rate in LAMP group was 12.0% and Kaplan–Meier analysis showed no significant differences among the 4 groups in TLF rate.

TLF-free suvival curves (Kaplan-Meier)

Conclusion

LAMP was observed by OCT at 6–12 months in 12.0% of lesions after 2G-DES implantation, which was not associated with TLF at 5 years.