Noninvasive Imaging Risk Stratification with Computed Tomography Angiography for Coronary Artery Disease

The recent technological evolution of coronary computed tomography angiography (CTA) with improved sensitivity and high negative predictive value has extended its potential applications as a gatekeeper test before invasive coronary angiography. However, the definition of the most accurate diagnostic algorithms comprising CTA as a first-line strategy for ruling out coronary artery disease and the correct management of the patients according to the results of imaging tests still warrant better definition.

Mechanisms and diagnostic evaluation of persistent or recurrent angina following percutaneous coronary revascularization

Persistence or recurrence of angina after a percutaneous coronary intervention (PCI) may affect about 20-40% of patients during short-medium-term follow-up. This appears to be true even when PCI is 'optimized' using physiology-guided approaches and drug-eluting stents. Importantly, persistent or recurrent angina post-PCI is associated with a significant economic burden. Healthcare costs may be almost two-fold higher among patients with persistent or recurrent angina post-PCI vs. those who become symptom-free. However, practice guideline recommendations regarding the management of patients with angina post-PCI are unclear. Gaps in evidence into the mechanisms of post-PCI angina are relevant, and more research seems warranted. The purpose of this document is to review potential mechanisms for the persistence or recurrence of angina post-PCI, propose a practical diagnostic algorithm, and summarize current knowledge gaps.

Association between ceramides and coronary artery stenosis in patients with coronary artery disease

BACKGROUND

Coronary artery stenosis induces heart diseases including acute coronary syndrome (ACS). Some studies reported the ceramide species are associated with the ACS and major adverse cardia and cerebrovascular events (MACE). However, few studies investigated the association between plasma ceramide levels and the severity of stenosis, together with the onset of diseases. This aim of the present study was to investigate the association betweencertain ceramide species, coronary artery stenosis and acute coronary syndrome.

METHODS

Five hundred fifty-three patients with definite or suspected CAD were recruited and received angiography. Subjects were assigned into 4 groups according to the severity of coronary artery stenosis. The measurements of 4 plasma ceramide species, namely, Cer (d18:1/16:0), Cer (d18:1/18:0), Cer (d18:1/24:1), Cer (d18:1/24:0) were carried out by Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and the ratio of Cer (d18:1/16:0), Cer (d18:1/18:0) and Cer (d18:1/24:1) to Cer (18:1/24:0), respectively, were calculated as index to evaluate the association between plasma ceramides levels and coronary artery stenosis. Multiple logistic regression analysis was used to establish the prognostic model for the prediction of ACS risk.

RESULTS

After the adjustment by multiple clinical risk factors including age, gender, pre-existing myocardial/cerebral infarction, hemoglobin A1c% (HbA1c%), smoking and the diagnosis during index hospitalization, multiple logistic regression analysis showed that the high ratio of Cer (d18:1/24:1) to Cer (d18:1/24:0), female gender, HbA1c%, unstable angina (UAP) and acute myocardial infarction (AMI) diagnosis (compared with atherosclerosis) during index hospitalization were associated with more severe coronary artery stenosis. Furthermore, the prognostic model was established after adjustment of risk factors and the area under curve (AUC) of receiver operating characteristics (ROC) for the prognostic model was 0.732 and 95% CI was 0.642-0.822.

CONCLUSION

The severity of coronary artery stenosis is associated with high ratio of Cer (d18:1/24:1) to Cer (d18:1/24:0), female gender, HbA1c% and AMI. Although the reported prognostic model showed a good discrimination, further investigation on long term MACE is needed to evaluate the role of ceramide for the prediction of MACE risk.

Drug-coated balloon versus drug-eluting stent for treating de novo coronary lesions in large vessels: a meta-analysis of clinical trials

BACKGROUND

Studies examining the efficiency of drug-coated balloon (DCB) compared to drug-eluting stents (DES) for de novo lesions in large vessels have reported inconsistent results.

OBJECTIVE

This comprehensive meta-analysis of clinical trials compared the efficacy and safety of DCB and DES for the treatment of de novo coronary lesions.

METHODS

The authors formally searched electronic databases before October 2019 to identify randomized and non-randomized clinical trials (RCTs and non-RCTs, respectively). Clinical trials were eligible for inclusion if they compared DCB with DES in patients with coronary lumen diameters >2.5 mm.

RESULTS

Three RCTs and one non-RCT with a total of 321 patients were included in our meta-analysis (DCB group = 152, DES group = 169). The primary endpoint was in-segment late lumen loss (LLL) with a standardized mean difference (SMD) of -0.07 (95% confidence interval [CI]: -0.31, 0.316; P = 0.548) and the secondary endpoint was target lesion revascularization (TLR) with a risk ratio (RR) of 1.17 (95% CI: 0.46, 2.95; P = 0.746).

CONCLUSION

This meta-analysis indicated that DCB might be non-inferior to DES as evidenced by quantitative coronary angiography (QCA) assessed at 6-9 months after percutaneous coronary intervention in patients presenting with coronary artery disease.

Relation between quantity and quality of peri-coronary epicardial adipose tissue and its underlying hemodynamically significant coronary stenosis

BACKGROUND

We aimed to investigate the association of lesion-specific epicardial adipose tissue (EAT) volume and density with the presence of myocardial ischemia.

METHODS

We enrolled 45 patients (55 lesions) with known or suspected coronary artery disease who underwent coronary computed tomography angiography (CTA) followed by invasive fractional flow reserve (FFR) assessment within 30 days. EAT volume (index) and density in patient-, vessel- and lesion-level were measured on CTA images. Lesion-specific ischemia was defined as a lesion with stenosis diameter > 90% or FFR ≤0.80. Multivariate analysis determined the independent association of EAT parameters with lesion-specific ischemia.

RESULTS

Mean age of the patients was 60 years, and 75% were male. Overall, 55.6% of patients had ischemic lesions and a mean FFR baseline value of 0.82 ± 0.10. Total EAT volume index was significantly higher in patients with functionally or anatomically significant stenosis. Specifically, peri-lesion EAT volume index, not the density, was positively correlated with lesion-specific ischemia independent of luminal stenosis and plaque characteristics (hazard ratio 1.56, 95% confidence interval 1.04-2.33, P = 0.032; per 0.1 ml/m² increase). Moreover, peri-lesion EAT volume was negatively correlated with lesion FFR values, whereas total EAT volume was positively correlated with fat accumulation and glucose metabolism. In addition, there was no association of EAT volume or density with myocardial ischemia in vessel-level analysis.

CONCLUSIONS

Lesion-specific EAT volume index, but not density, seems positively and independently associated with myocardial ischemia, while its incremental diagnostic value of lesion-specific ischemia should be further investigated.

Diagnostic Accuracy of Cardiac Magnetic Resonance Versus Fractional Flow Reserve: A Systematic Review and Meta-Analysis

Background

Fractional flow reserve (FFR) is considered the gold standard for diagnosis of coronary artery disease (CAD). Stress Cardiac magnetic resonance (SCMR) has been recently gaining traction as a non-invasive alternative to FFR.

Methods

Studies comparing the diagnostic accuracy of SCMR versus FFR were identified and analyzed using Review Manager (RevMan) 5.3 and Stata software.

Results

A total of 28 studies, comprising 2,387 patients, were included. The pooled sensitivity and specificity for SCMR were 86% and 86% at the patient level, and 82% and 88% at the vessel level, respectively. When the patient-level data were stratified based on the FFR thresholds, higher sensitivity and specificity (both 90%) were noted with the higher cutoff (0.75) and lower cutoff (0.8), respectively. At the vessel level, sensitivity and specificity at the lower FFR threshold were significantly higher at 88% and 89%, compared to the corresponding values for higher cutoff at 0.75. Similarly, meta-regression analysis of SCMR at higher (3T) resolution showed a higher sensitivity of 87% at the patient level and higher specificity of 90% at the vessel level. The highest sensitivity and specificity of SCMR (92% and 94%, respectively) were noted in studies with CAD prevalence greater than 60%.

Conclusions

SCMR has high diagnostic accuracy for CAD comparable to FFR at a spatial resolution of 3T and an FFR cut-off of 0.80. An increase in CAD prevalence further improved the specificity of SCMR.

Inflammasome activation by NLRP1 and NLRC4 in patients with coronary stenosis

OBJECTIVE AND DESIGN

We performed an experimental, analytical and prospective study to evaluate the systemic activation of inflammasome in atherosclerosis' patients, in order to shed light into responsible mechanisms for plaque formation.

SUBJECTS

We included sixty individuals distributed into 3 groups: 2 groups based on the report from the angiography (severe lesions - SL and primary lesions - PL) and 1 group enclosing healthy individuals (HC).

METHODS

The expression assays of inflammasome genes NLRP1, NLRC4, CASP-1 and IL-1β were performed using Real Time qPCR, with specific Taqman Assays. IL-1β serum levels were analysed by commercial kit. Were applied the Shapiro-Wilk and Student's T-test as statistical tests. Statistical significance was set to p ≤ 0.05.

RESULTS

Upregulation of NLRP1 (+3.47 FC, p = 0.0001), NLRC4 (+7.06 FC, p = 6.792 × 10^-09) and IL-1β (+2.43 FC, p = 0.005) was observed in all atherosclerosis patients when compared to HC. According to stenosis severity, patients with primary lesions showed upregulation of inflammasome genes NLRP1 (+2.87 FC, p = 0.0008), NLRC4 (+6.34 FC, p = 4.134 × 10^-07) and IL-1β (+3.39 FC, p = 0.0012) with respect to the HC group. No statistical difference was found in IL-1β serum levels according the assessed groups.

CONCLUSIONS

Inflammasome activation in atherosclerosis's patients can be systemic altered and may be triggered by NLRP1 and NLRC4 receptors. IL-1β gene expression was identified in our study as an important systemic detectable marker of plaque severity.

The impact of iterative reconstruction algorithms on machine learning-based coronary CT angiography-derived fractional flow reserve (CT-FFRML) values

To evaluate the impact of an iterative reconstruction (IR) algorithm (advanced modeled iterative reconstruction, ADMIRE) on machine learning-based coronary computed tomography angiography-derived fractional flow reserve (CT-FFR_ML) measurements compared with filtered back projection (FBP). 170 plaque-containing vessels in 107 patients were included. CT-FFR_ML values were measured and compared among 5 imaging reconstruction algorithms (FBP and ADMIRE at strength levels of 1, 2, 3 and 5). The plaques were classified as, 'calcified" or "noncalcified" and "≥ 50% stenosis" or "< 50% stenosis', a total of four subgroups by consensus. There were no significant differences of CT-FFR_ML values among the FBP and ADMIRE 1, 2, 3 and 5 groups wherever comparisons were done at the level of subgroups (P = 0.676, 0.414, 0.849, 0.873, respectively) or overall (P = 0.072). There were 20, 21, 19, 19 and 29 vessels with lesion-specific ischemia (CT-FFR_ML ≤ 0.80) in FBP and ADMIRE 1, 2, 3 and 5 datasets, respectively, but no statistical differences were found (P = 0.437). Compared with CT-FFR_ML value of FBP dataset, the CT-FFR_ML values of 9 (5.3%) vessels from 8 patients (7.5%) in ADMIRE5 dataset switched from above 0.8 to below or equal to 0.8. There were no significant differences of the CT-FFR_ML values among the FBP and IR image algorithms at different strength levels. However, high iterative strength level (ADMIRE 5) was not recommended, which might have an impact on diagnosis of lesion-specific ischemia, although changes only occurred in a modest number of subjects.

A 90-second magnetocardiogram using a novel analysis system to assess for coronary artery stenosis in Emergency department observation unit chest pain patients

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Magnetocardiography non-invasively detects coronary artery stenosis.

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Emergency department chest pain patients are further evaluated in observation unit.

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Patients underwent 90-second magnetocardiography scan using novel analysis system.

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Results compared to usual care with stress testing and coronary angiography.

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Magnetocardiography shows promise as feasible and comparable testing option.

Background

Magnetocardiography (MCG) has been shown to non-invasively detect coronary artery stenosis (CAS). Emergency department (ED) patients with possible acute coronary syndrome (ACS) are commonly placed in an observation unit (OU) for further evaluation. Our objective was to compare a novel MCG analysis system with stress testing (ST) and/or coronary angiography (CA) in non-high risk EDOU chest pain patients.

Methods

This is a prospective pilot study of non-high risk EDOU chest pain patients evaluated with ST and/or CA that underwent a resting 90-second MCG scan between August 2017 and February 2018. A positive MCG scan was defined as having current dipole deviations with dispersion or splitting during the repolarization phase. ST, CA and major adverse cardiac events (MACE) 30 days and 6 months post-discharge assessed.

Results

Of 101 study patients, mean age was 56 years and 53.6% were male. MCG scan sensitivity with 95% CI was 27.3% [7.3%, 60.7%], specificity 77.8% [67.5%, 85.6%], PPV 13.0% [3.4%, 34.7%] and NPV 89.7% [80.3%, 95.2%] compared to ST, and 33.3% [7.5%, 70.7%], 78.3% [68.4%, 86.2%], 13% [5.2%, 29.0%] and 92.3% [88.2%, 95.1%] respectively compared to ST and CA. No patients had positive ST, CA or MACE 30 days and 6 months post-discharge.

Conclusion

This pilot study suggests a resting 90-second MCG scan shows promise in evaluating EDOU chest pain patients for CAS and warrants further study as an alternative testing modality to identify patients safe for discharge. Larger studies are needed to assess accuracy of MCG using this novel analysis system.

Clinical Impact of High-Sensitivity Cardiac Troponin T on the Chronic Phase of Stable Angina after a Successful Initial Percutaneous Coronary Intervention

BACKGROUND

The purpose of this study was to investigate the clinical significance of elevated plasma high-sensitivity troponin T (hs-TnT) in the chronic phase in patients with stable angina pectoris (SAP) who underwent a successful percutaneous coronary intervention (PCI).

METHODS

This study enrolled 158 consecutive SAP patients who underwent routine follow-up coronary angiography 9 months after a successful PCI with the implantation of a second-generation drug-eluting stent. Patients with previous coronary artery bypass graft and renal dysfunction were excluded. Patients were divided into two groups according to hs-TnT plasma level at follow-up: elevated hs-TnT (≥ 0.015 ng/ml) group and non-elevated hs-TnT group.

RESULTS

Among the 158 subjects, 42 had an elevated hs-TnT level at follow-up. The elevated hs-TnT group had a significantly higher rate of any coronary lesion (in-stent restenosis and de novo lesions) in follow-up CAG (coronary angiography) than the non-elevated group (28.6% vs. 10.3%, p < 0.05). Multivariate analysis also showed that hs-TnT elevation was independently associated with the presence of significant coronary stenosis in the chronic phase (odds ratio: 3.99, 95% confidence interval: 1.38 to 11.53). The best cut-off value of the hs-TnT level at 9 months after a successful PCI to predict the presence of significant coronary stenosis was 0.016 ng/ml (sensitivity: 50.0%; specificity: 82.1%; area under the receiver operating characteristic curve: 0.67).

CONCLUSIONS

hs-TnT elevation was independently associated with the presence of coronary stenosis in the chronic phase in SAP patients with successful PCI. Routine measurement of hs-TnT in the chronic phase may be useful to refine the risk of patients after PCI.

Potential Gains of Screening Family Members of Suspected Coronary Artery Disease: A Pilot Study

Background:

Early diagnosis of asymptomatic coronary artery disease (CAD) is presently targeted in preventive cardiology. A positive family history though not modifiable can provide a window of opportunity for intervening on modifiable risk factors. We assessed the prevalence of risk factors among the family members of suspected CAD patients and estimated their 10 years CAD risk.

Methods:

In a hospital-based cross-sectional study, socio-demographic, personal data and blood samples for total and HDL cholesterol were collected. The risk of having a heart attack in the next 10 years was calculated using Framingham Risk Score.

Results:

The mean age of participants (n = 60) was 40.55 ± 1.78 years. 85% were physically inactive. Smoking (13%), alcohol use (12%), history of CAD (2%), HTN (12%) and diabetes (22%) were the observed risk factors. A family history of CAD at <40 years of age was reported by 7% of subjects. Prevalence of overweight was 21% and 11% were obese. Increased waist-hip ratio (43%), diabetes (22%), hypercholesterolemia (28%), reduced HDL Cholesterol (48%) were other prevalent risk factors. Risk of CAD of >1% in the next 10 years was noted among 60% of subjects.

Conclusions:

Window of opportunity for secondary prevention exists among the family members of suspected CAD.

[Radiological imaging to assess individual cardiovascular risk]

CLINICAL/METHODICAL ISSUE

Radiologic imaging for the assessment of individual cardiovascular risk.

STANDARD RADIOLOGICAL METHODS

The correct estimation of the individual cardiovascular risk is prerequisite for the prevention of cardiovascular diseases. Here, extensive evidence is available for coronary calcium scans as well as coronary CT angiography (CTA).

METHODICAL INNOVATIONS

Summary of the available evidence for the use of calcium score and coronary CTA. Illustration of the significance of both tests in current guidelines.

PERFORMANCE

Both tests have high prognostic value, surpassing a risk-factor based assessment. In comparison with the calcium score, the CTA has higher incremental value.

ACHIEVEMENTS

Results from recent trials confirm an improvement of outcomes in symptomatic patients by performing a CTA compared with standard care.

PRACTICAL RECOMMENDATIONS

European and US guidelines recommend a calcium score for risk stratification of asymptomatic patients with a low to intermediate risk profile. For symptomatic patients with low to intermediate coronary artery disease pretest probability, a CTA is recommended.

Latent tuberculosis infection among patients with coronary artery stenosis: A case-Control study

Background

The activation of the cell-mediated immune responses by Mycobacterium tuberculosis can promote atherogenesis.

Aims

The aim of this study is to determine the frequency of latent tuberculosis infection (LTBI) among patients with coronary artery stenosis (CAS) and to explore the association between LTBI and development of CAS. We conducted a case-control study which included 183 patients' who underwent percutaneous coronary angiography (121 patients with CAS and 62 patients without as a control group).

Methods

For all the study population, clinical evaluation, tuberculin skin test (TST), imaging studies (including chest radiography and echocardiography), laboratory investigations, and electrocardiography were carried out. Only for the patients with positive TST, QuantiFERON-TB Gold test was performed. Predictors of CAS were identified using univariate analyses (Yates' corrected Chi-square test or Fischer's exact test) followed by multivariate analysis (binary logistic regression).

Results

Among 29.5% of the study population, LTBI was detected, and among patients with CAS, 56.2% of patients had advanced CAS. After multivariate analysis, it was found that metabolic syndrome (MS) (odds ratio [OR] 3.6, 95% confidence interval [CI] 1.5-22.6, P = 0.022) and LTBI (OR 2.5, 95% CI 1.2-17.3, P = 0.018) were the predictors of CAS among the study population, while only diabetes mellitus (DM) (OR 1.9, 95% CI 1.1-11.7, P = 0.031) was the predictor of advanced CAS.

Conclusion

LTBI is associated with the development of CAS. In addition, MS is associated with CAS, while its related disorder, DM, is associated with advanced CAS.

The relationship between radiation doses to coronary arteries and location of coronary stenosis requiring intervention in breast cancer survivors

Background

To assess the relationship between radiation doses to the coronary arteries (CAs) and location of a coronary stenosis that required intervention after three-dimensional conformal radiotherapy (3DCRT) for breast cancer (BC).

Methods

The study population consisted of 182 women treated for BC in Sweden between 1992 and 2012. All women received 3DCRT and subsequently underwent coronary angiography due to a suspected coronary event. CA segments were delineated in the patient’s original planning-CT and radiation doses were recalculated based on the dose distribution of the original radiotherapy (RT) plan. The location of the CA stenosis that required intervention was identified from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR). Logistic regression analysis was used to assess the relationship between CA radiation doses and risk of a later coronary intervention at this specific location.

Results

The odds ratio (OR) varied by radiation dose to the mid left anterior descending artery (LAD) (p = 0.005). Women receiving mean doses of 1–5 Gray (Gy) to the mid LAD had an adjusted OR of 0.90 (95% CI 0.47–1.74) for a later coronary intervention compared to women receiving mean doses of 0–1 Gy to the mid LAD. In women receiving mean doses of 5–20 Gy to the mid LAD, an adjusted OR of 1.24 (95% CI 0.52–2.95) was observed, which increased to an OR of 5.23 (95% CI 2.01–13.6) for mean doses over 20 Gy, when compared to women receiving mean doses of 0–1 Gy to the mid LAD.

Conclusions

In women receiving conventional 3DCRT for BC between 1992 and 2012, radiation doses to the LAD remained high and were associated with an increased requirement of coronary intervention in mid LAD. The results support that the LAD radiation dose should be considered in RT treatment planning and that the dose should be kept as low as possible. Minimising the dose to LAD is expected to diminish the risk of later radiation-induced stenosis.

Electronic supplementary material

The online version of this article (10.1186/s13014-019-1242-z) contains supplementary material, which is available to authorized users.

Assessment of coronary flow velocity reserve with phase-contrast cine magnetic resonance imaging in patients with heavy coronary calcification

Coronary flow velocity reserve (CFVR) can be noninvasively measured by phase-contrast cine magnetic resonance imaging (PC-MRI). Heavy coronary calcification degrades the diagnostic accuracy for the detection of coronary arterial stenosis on computed tomography (CT). The aim of this study was to evaluate the value of CFVR measurement with PC-MRI for detecting significant coronary stenoses in patients with heavy coronary calcification. Sixteen patients (71 ± 8 years) with coronary calcium score above 400 who had suspected moderate coronary stenosis (50-69% diameter stenosis) on CT angiography were prospectively studied. The CFVR values, calculated as the ratio of peak flow velocity during hyperemia to the peak flow velocity at rest, were measured using breath-hold PC-MRI with 3 T system, and were compared with the results of quantitative coronary angiography (QCA). The mean coronary calcium score was 985 ± 378. CFVR was successfully determined with PC-MRI in 17/18 (94%) vessels. Using a threshold of 1.4 for CFVR, the sensitivity, specificity, and positive and negative predictive value for detecting ≥ 50% stenosis on QCA was 88% (7/8), 89% (8/9), 88% (7/8), 89% (8/9), respectively. When MRI CFVR measurements was added to CT angiography for the evaluation of coronary stenosis, the positive predictive value was 88% (7/8), while the positive predictive value of CT angiography alone was 44% (8/18). PC-MRI can provide noninvasive detection of altered CFVR caused by significant stenosis in patient. CFVR measurement by PC-MRI is useful for diagnosing physiologically significant coronary stenosis in patients with high calcium score on CT.

Instantaneous wave-free ratio (iFR®) to determine hemodynamically significant coronary stenosis: A comprehensive review

Coronary angiography is considered to be the gold standard in the morphological evaluation of coronary artery stenosis. The morphological assessment of the severity of a coronary lesion is very subjective. Thus, the invasive fractional flow reserve (FFR) measurement represents the current standard for estimation of the hemodynamic significance of coronary artery stenosis. The FFR-guided revascularization strategy was initially classified as a Class-IA-recommendation in the 2014 European Society of Cardiology/European Association for Cardio-Thoracic Surgery guidelines on myocardial revascularization. Both the Deferral vs Performance of Percutaneous Coronary Intervention of Functionally Non-Significant Coronary Stenosis and Flow Reserve vs Angiography for Multivessel Evaluation studies showed no treatment advantage for hemodynamically insignificant stenoses. With the help of FFR (and targeted interventions), clinical results could be improved; however, the use in clinical practice is still limited due to the need of adenosine administration and a significant prolongation of the length of the procedure. Instantaneous wave-free ratio (iFR®) is a new innovative approach for the determination of the hemodynamic significance of coronary stenosis, which can be obtained at rest without the use of vasodilators. Regarding the periprocedural complications as well as prognosis, iFR® showed non-inferiority to FFR in the SWEDEHEART and DEFINE-FLAIR trials. Furthermore, iFR®, enhanced by iFR®-pullback, provides the possibility to display the iFR®-change over the course of the vessel to create a hemodynamic map.

Correlation of FFR-derived from CT and stress perfusion CMR with invasive FFR in intermediate-grade coronary artery stenosis

Only one-third of intermediate-grade coronary artery stenosis (i.e. 40-70% diameter narrowing) causes myocardial ischemia, requiring most often additional invasive work-up with invasive fractional flow reserve (FFR). To evaluate the correlations between FFR estimates derived from computed tomography (FFR_CT) and adenosine perfusion cardiac magnetic resonance (CMR) with invasive FFR in intermediate-grade stenosis. Thirty-seven patients (mean age 61 ± 9 years; 25 men) who underwent adenosine perfusion CMR, quantitative coronary angiography and FFR in the work-up for intermediate-grade stenoses (n = 39) diagnosed at coronary CT angiography were retrospectively evaluated. Blinded FFR_CT analysis was computed on each intermediate-grade lesion and correlated to the FFR values. On adenosine CMR, subendocardial time-enhancement maximal upslopes, normalized by respective left ventricle cavity upslopes, were obtained distal to a coronary stenosis (RISK area) and in remote myocardium (REMOTE area). The perfusion was subsequently assessed without (uncorrected RISK) and after correction for remote perfusion (relative myocardial perfusion index = REMOTE/RISK ratio), and then correlated to the FFR values. Differences in correlations were tested with z statistics and considered statistically significant different at a p < 0.05 level. The average FFR value was 0.85 ± 0.10 (0.60-0.98 range), 28% (n = 11) was ≤ 0.80. FFR value correlated poorly with uncorrected RISK upslopes (r = 0.151; p = 0.36), but equally strongly with FFR_CT (r = 0.675; p < 0.001) and the relative myocardial perfusion index (r = - 0.63) (p < 0.001; z = 6.72) for assessment of lesion-specific ischemia. Both FFR_CT and adenosine perfusion CMR strongly correlate with invasive FFR measurements for intermediate-grade stenosis. These preliminary findings pave the way for further studies evaluating non-invasively intermediate coronary stenosis in clinical practice.

Concertina Phenomenon in the Left Anterior Descending Artery: An Unexpected Circumstance in an Unexpected Vessel

The concertina phenomenon is the occurrence of new and transient angiographic series of pseudolesions in a tortuous vessel induced mainly by a stiff guide wire. Here, we describe a 53-year-old man who experienced a concertina effect in the left anterior descending coronary artery (LAD) during an elective percutaneous coronary intervention. After the diagnosis of the concertina phenomenon in the LAD, a percutaneous coronary intervention was performed following the withdrawal of the soft guide wire to the mid level of the LAD. After the intervention, the patient remained in very good clinical status and was discharged on the third postprocedural day.

Discordance between pressure drift after wire pullback and intracoronary distal pressure offset affects stenosis physiology appraisal

BACKGROUND

Drift is a well-known issue affecting intracoronary pressure measurements. A small pressure offset at the end of the procedure is generally considered acceptable, while repeat assessment is advised for drift exceeding ±2 mmHg. This practice implies that drift assessed after wire pullback equals that at the time of stenosis appraisal, but this assumption has not been systematically investigated. Our aim was to compare intra-and post-procedural pressure sensor drift and assess benefits of correction for intra-procedural drift and its effect on diagnostic classification.

METHODS

In 70 patients we compared intra- and post-procedural pressure drift for 120 hemodynamic tracings obtained at baseline and throughout the hyperemic response to intracoronary adenosine. Intra-procedural drift was derived from the intercept of the stenosis pressure gradient-velocity relationship. Diagnostic reclassification after correction for intra-procedural drift was assessed for the mean distal-to-aortic pressure ratio at baseline (Pd/Pa) and hyperemia (fractional flow reserve, FFR), and corresponding stenosis resistances.

RESULTS

Post- and intra-procedural drift exceeding the tolerated threshold was observed in 73% and 64% of the hemodynamic tracings, respectively. Discordance in terms of acceptable drift level was present for 42% of the tracings, with avoidable repeat physiological assessment in 25% and unacceptable intra-procedural drift unrecognized at final drift check in 17% of the tracings. Correction for intra-procedural drift caused higher reclassification rates for baseline than hyperemic functional indices.

CONCLUSIONS

Post-procedural pressure drift frequently does not match drift during physiological assessment. Tracing-specific correction for intra-procedural drift can potentially lower the risk of inadvertent diagnostic misclassification and prevent unnecessary repeats.

The characteristics of coronary stenosis in 11,267 patients from Southwest China: a retrospective study

The characteristics of coronary stenosis vary among the different countries or areas. 11,267 patients who have undergone coronary angiography (CAG) from three Southwest China hospitals were investigated. Patient characteristics, coronary stenosis and stent-implant information were recorded and analyzed according to two criteria: "visible stenosis" and "≥ 50% stenosis". The patients who have undergone CAG increased year by year, with patients from 60 to 69 years-old taking the highest ratio (34.69%). Based on the "≥ 50% stenosis" criteria, the stenotic frequency was 40.54% for Southwest China patients getting CAG. Only 8.14% patients suffered ≥ 3 stenotic vessels, while 11.58 and 20.82% patients had 2 or 1 stenotic vessel, respectively. However, when using the "visible stenosis" criteria, the stenotic frequency increased to 64.68%. The prevalence of stenosis increased with age based on the "visible stenosis" criteria. There were more male patients with stenosis than female except patients over 80 years old. The stenosis affected almost all main coronary arteries and their branches, with the most affected artery being the left anterior descending artery. There were 3246 cases (28.8%) implanted with 5423 stents with a concurrent age-dependent increasing tendency for stent-implant frequency and average implanted stent number. The numbers of patients who have undergone CAG and suffered from CVD increased rapidly. In these patients, positive rate of CAG was 64.67%, which increased to 72.2% in patients over 60-years old. The incidence of ≥ 75% stenosis and multiple stenosis increased with age, however it should be noticed there were 18.93% for ≥ 75% stenosis and 19.52% for multiple stenosis in patients under 40 years old.

Peripheral-blood gene expression profiling studies for coronary artery disease and its severity in Xinjiang population in China

Background

Alterations in gene expression in peripheral blood cells play a curtail role in the presence and extent of coronary artery disease (CAD), but its severity reflected by gene expression alterations in peripheral blood cells is still unknown in Xinjiang population in China.

Methods

Global gene expression profiling in peripheral blood was used to explore differentially expressed genes in coronary artery stenosis patients. RNA was extracted from peripheral blood of 9 controls without coronary stenosis and 21 cases with angiographically CAD. The extent of CAD severity was categorized angiographically as no CAD, mild CAD (20 to 50% luminal diameter stenosis [LDS]), moderate CAD (50 to 75% LDS) and severe CAD (≥75% LDS). Differentially expressed genes related with CAD severity from peripheral blood cells were screened by linear mixed effects analysis using the lme4 package in R. Then the differentially expressed genes that gradually up-regulated or down-regulated were enriched by Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis.

Results

The most significantly enrichments were toll-like receptor signaling pathway, immune responses, translational processes, cellular growth, inflammation and metabolic processes. Combined with NCBI-GeneRIF and PubMed analysis, we focused on the 12 genes associated with toll-like receptor signaling pathway in the extent of coronary artery stenosis patients. Receiver operating characteristic (ROC) analysis of 12 genes associated with toll-receptor signaling pathway in the 236 CAD patients from GEO database demonstrated that 12 genes expression could predict severe CAD with an area under the curve of 0.67, sensitivity of 77.65% and specificity of 51.52%.

Conclusion

These results suggest that 12 genes associated with toll-like receptor signaling pathway in peripheral-blood cells reflect the presence and extent of CAD severity in Xinjiang population in China.

Electronic supplementary material

The online version of this article (10.1186/s12944-018-0798-1) contains supplementary material, which is available to authorized users.

The clinical evaluation of the CADence device in the acoustic detection of coronary artery disease

The noninvasive detection of turbulent coronary flow may enable diagnosis of significant coronary artery disease (CAD) using novel sensor and analytic technology. Eligible patients (n = 1013) with chest pain and CAD risk factors undergoing nuclear stress testing were studied using the CADence (AUM Cardiovascular Inc., Northfield MN) acoustic detection (AD) system. The trial was designed to demonstrate non-inferiority of AD for diagnostic accuracy in detecting significant CAD as compared to an objective performance criteria (sensitivity 83% and specificity 80%, with 15% non-inferiority margins) for nuclear stress testing. AD analysis was blinded to clinical, core lab-adjudicated angiographic, and nuclear data. The presence of significant CAD was determined by computed tomographic (CCTA) or invasive angiography. A total of 1013 subjects without prior coronary revascularization or Q-wave myocardial infarction were enrolled. Primary analysis was performed on subjects with complete angiographic and AD data (n = 763) including 111 subjects (15%) with severe CAD based on CCTA (n = 34) and invasive angiography (n = 77). The sensitivity and specificity of AD were 78% (p = 0.012 for non-inferiority) and 35% (p < 0.001 for failure to demonstrate non-inferiority), respectively. AD results had a high 91% negative predictive value for the presence of significant CAD. AD testing failed to demonstrate non-inferior diagnostic accuracy as compared to the historical performance of a nuclear stress OPC due to low specificity. AD sensitivity was non-inferior in detecting significant CAD with a high negative predictive value supporting a potential value in excluding CAD.

Instantaneous wave-free ratio and fractional flow reserve in clinical practice

Objectives

To compare fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) measurements in an all-comer patient population with moderate coronary artery stenoses.

Background

Visual assessment of the severity of coronary artery stenoses is often discordant in moderate lesions. FFR allows reliable functional severity assessment in these cases but requires adenosine-induced hyperaemia with associated additional time, costs and side effects. The iFR is a hyperaemia-independent index.

Methods and results

Between November 2015 and February 2017, 356 consecutive patients were included in whom 515 coronary stenoses were measured using both iFR and FFR. Mean iFR and FFR were 0.90 ± 0.09 and 0.86 ± 0.08, respectively. iFR correlated well with FFR [r = 0.75; p < 0.001]. Receiver operating characteristic analysis identified an area under the curve of 0.92. An iFR-only strategy with a treatment cut-off ≤0.89 revealed a diagnostic classification agreement with the FFR-only strategy in 420 lesions (82%) with a sensitivity of 87%, a specificity of 80%, a positive predictive value of 56% and a negative predictive value of 96%.

Conclusions

Real-time iFR measurements have good negative predictive value compared to FFR, but moderate diagnostic accuracy (82%). It exposes fewer patients to adenosine, reduces procedure time and costs. Further prospective trials are needed to evaluate specific clinical settings, cut-off values and endpoints.

High Brachial Ankle Pulse Wave Velocity as a Marker for Predicting Coronary Artery Stenosis in Patients with Type 2 Diabetes

BACKGROUND

We evaluated the ability of brachial ankle pulse wave velocity (baPWV) to predict coronary artery stenosis (CAS) in patients with type 2 diabetes, and compared the predictive power of baPWV to that of well-known cardiovascular disease (CVD) risk calculators.

METHODS

The study group included 83 consecutive patients over 30 years old with type 2 diabetes who complained of vague chest discomfort. An automatic pulse waveform analyzer was used to measure baPWV. CAS was measured using multi-slice computed tomographic (MSCT) angiography.

RESULTS

Age, maximal baPWV, duration of diabetes, current smoking, the UK Prospective Diabetes Study (UKPDS) Risk Engine score, American College of Cardiology/American Heart Association (ACC/AHA) risk estimator score, the Framingham risk calculator score, and coronary artery calcium score were greater in patients with CAS than in those without CAS. An area under the curve (AUC) indicative of a predictive value for CAS (≥20%) was found for several parameters. The AUC of maximal baPWV, the UKPDS Risk Engine, the ACC/AHA ASCVD risk estimator, and the Framingham risk calculator were 0.672 (95% confidence interval [CI], 0.554 to 0.785; P=0.010), 0.777 (95% CI, 0.675 to 0.878; P<0.001), 0.763 (95% CI, 0.660 to 0.866; P<0.001), and 0.736 (95% CI, 0.629 to 0.843; P<0.001), respectively. The optimal cutoff value of baPWV for the detection of CAS was 1,650 cm/sec (sensitivity, 68.9%; specificity, 63.2%).

CONCLUSION

Maximal baPWV was closely related with CAS detected by MSCT coronary angiography in patients with type 2 diabetes. baPWV has the potential to be a useful, noninvasive screening tool for the prediction of occult CAS in patients with type 2 diabetes.

Integrated prediction of lesion-specific ischaemia from quantitative coronary CT angiography using machine learning: a multicentre study

OBJECTIVES

We aimed to investigate if lesion-specific ischaemia by invasive fractional flow reserve (FFR) can be predicted by an integrated machine learning (ML) ischaemia risk score from quantitative plaque measures from coronary computed tomography angiography (CTA).

METHODS

In a multicentre trial of 254 patients, CTA and invasive coronary angiography were performed, with FFR in 484 vessels. CTA data sets were analysed by semi-automated software to quantify stenosis and non-calcified (NCP), low-density NCP (LD-NCP, < 30 HU), calcified and total plaque volumes, contrast density difference (CDD, maximum difference in luminal attenuation per unit area) and plaque length. ML integration included automated feature selection and model building from quantitative CTA with a boosted ensemble algorithm, and tenfold stratified cross-validation.

RESULTS

Eighty patients had ischaemia by FFR (FFR ≤ 0.80) in 100 vessels. Information gain for predicting ischaemia was highest for CDD (0.172), followed by LD-NCP (0.125), NCP (0.097), and total plaque volumes (0.092). ML exhibited higher area-under-the-curve (0.84) than individual CTA measures, including stenosis (0.76), LD-NCP volume (0.77), total plaque volume (0.74) and pre-test likelihood of coronary artery disease (CAD) (0.63); p < 0.006.

CONCLUSIONS

Integrated ML ischaemia risk score improved the prediction of lesion-specific ischaemia by invasive FFR, over stenosis, plaque measures and pre-test likelihood of CAD.

KEY POINTS

• Integrated ischaemia risk score improved prediction of ischaemia over quantitative plaque measures • Integrated ischaemia risk score showed higher prediction of ischaemia than standard approach • Contrast density difference had the highest information gain to identify lesion-specific ischaemia.