Mark Rabbat

Comprehensive Meta-Analysis on Drug-Eluting Stents versus Bare-Metal Stents during Extended Follow-up

BACKGROUND Several observational reports have documented both increased and decreased cardiac mortality or Q-wave myocardial infarction with drug-eluting stents compared with bare-metal stents. METHODS We sought to evaluate the safety and efficacy of drug-eluting stents compared with bare-metal stents early after intervention (<1 year) and late (>1 year) among a broad population of patients, using a meta-analysis of randomized clinical trials. RESULTS We identified 28 trials with a total of 10,727 patients and a mean follow-up of 29.6 months. For early outcomes (<1 year), all-cause mortality for drug-eluting stents versus bare-metal stents was 2.1% versus 2.4% (risk ratio [RR] 0.91, [95% confidence interval (CI), 0.70-1.18]; P=.47), non-Q-wave myocardial infarction was 3.3% versus 4.4% (RR 0.78 [95% CI, 0.61-1.00]; P=.055), target lesion revascularization was 5.8% versus 18.4% (RR 0.28 [95% CI, 0.21-0.38]; P <.001), and stent thrombosis was 1.1% versus 1.3% (RR 0.87 [95% CI, 0.60-1.26]; P=.47). For late outcomes (>1 year), all-cause mortality for drug-eluting stents versus bare-metal stents was 5.9% versus 5.7% (RR 1.03 [95% CI, 0.83-1.28]; P=.79), target lesion revascularization was 4.0% versus 3.3% (RR 1.22 [95% CI, 0.92-1.60]; P=.16), non-Q-wave myocardial infarction was 1.6% versus 1.2% (RR 1.36 [95% CI, 0.74-2.53]; P=.32) and stent thrombosis was 0.7% versus 0.1% (RR 4.57 [95% CI, 1.54-13.57]; P=.006). CONCLUSIONS There was no excess mortality with drug-eluting stents. Within 1 year, drug-eluting stents appear to be safe and efficacious with possibly decreased non-Q-wave myocardial infarction compared with bare-metal stents. After 1 year, drug-eluting stents still have similar mortality, despite increased stent thrombosis. The reduction in target lesion revascularization with drug-eluting stents mainly happens within 1 year, but is sustained thereafter.

Interpreting results of coronary computed tomography angiography-derived fractional flow reserve in clinical practice

The application of computational fluid dynamics to coronary computed tomography angiography allows Fractional Flow Reserve (FFR) to be calculated non-invasively (FFRCT), enabling computation of FFR from coronary computed tomography angiography acquired at rest both for individual lesions as well as along the entire course of a coronary artery. FFRCT, validated in a number of accuracy studies and a large clinical utility trial, is beginning to penetrate clinical practice. Importantly, while accuracy trials compared FFRCT to invasively measured FFR at a single point in the coronary tree, clinical reports of FFRCT provide information regarding a patients entire coronary vasculature. Specifically, in distal coronary segments, calculated FFRCT values may be low and below 0.80 even in the absence of localized stenoses within the course of the artery. As a result, the reporting physician needs to understand how to interpret the findings in a clinically useful and thoughtful fashion. This review provides a brief overview of the background of both invasively measured and computationally derived FFR, explains changes in FFR along the course of normal coronary arteries and those affected by coronary atherosclerosis, and outlines the relevance of measurement location when interpreting and reporting FFR and FFRCT results.

Rationale, design and goals of the HeartFlow assessing diagnostic value of non-invasive FFRCT in Coronary Care (ADVANCE) registry

BACKGROUND Coronary CT angiography (CTA) is a reliable tool for the detection of coronary artery disease (CAD) that conveys significant prognostic information. It does not provide data on the hemodynamic significance of a given lesion, particularly in intermediate-grade stenosis. Fractional flow reserve by CT (FFRCT) can accurately predict the hemodynamic significance of coronary lesions. The primary objective of this registry is to determine whether the integration of FFRCT as an adjunct to coronary CTA will lead to a significant change in the management of CAD in patients with stable angina. METHODS The ADVANCE Registry is a multi-center, prospective registry designed to evaluate utility, clinical outcomes and resource utilization following FFRCT-guided treatment in clinically stable, symptomatic patients diagnosed with CAD by coronary CTA. Approximately 5000 patients will be enrolled from up to 50 sites in Europe, USA, Canada and Asia. Requirement for enrollment is the presence of atherosclerosis on coronary CTA. For each enrolled patient, a clinical management review committee will use data from coronary CTA and FFRCT to determine the management plan using the following criteria: (a) optimal medical therapy, (b) percutaneous coronary intervention, (c) coronary artery bypass graft surgery, or (d) more information required. The primary endpoint of the registry is the reclassification rate between the management plan based on coronary CTA alone versus CTA plus FFRCT. The secondary endpoints of the registry include the evaluation of the rate of invasive coronary angiography (ICA), revascularization, major adverse coronary events, resource utilization, cumulative radiation dose exposure and the rate of ICA without obstructive CAD at 3-year follow-up. CONCLUSIONS The ADVANCE registry is designed to assess the real-world impact of FFRCT on the clinical management of stable CAD when used along with coronary CTA.

Prognostic stratification of patients with ST-segment-elevation myocardial infarction (PROSPECT): A cardiac magnetic resonance study

Background— Cardiac magnetic resonance (CMR) is a robust tool to evaluate left ventricular ejection fraction (LVEF), myocardial salvage index, microvascular obstruction, and myocardial hemorrhage in patients with ST-segment–elevation myocardial infarction. We evaluated the additional prognostic benefit of a CMR score over standard prognostic stratification with global registry of acute coronary events (GRACE) score and transthoracic echocardiography LVEF measurement. Methods and Results— Two hundred nine consecutive patients with ST-segment–elevation myocardial infarction (age, 61.4±11.4 years; 162 men) underwent transthoracic echocardiography and CMR after succesful primary percutaneous coronary intervention. Major adverse cardiac events (MACE) were assessed at a mean follow-up of 2.5±1.2 years. MACE occurred in 24 (12%) patients who at baseline showed higher GRACE risk score (P<0.01), lower LVEF with both transthoracic echocardiography and CMR, lower myocardial salvage index, and higher per-patient myocardial hemorrhage and microvascular obstruction prevalence and amount as compared with patients without MACE (P<0.01). The best cut-off values of transthoracic echocardiography-LVEF, CMR-LVEF, myocardial salvage index, and microvascular obstruction to predict MACE were 46.7%, 37.5%, 0.4, and 2.6% of left ventricular mass, respectively. Accordingly, a weighted CMR score, including the following 4 variables (CMR-LVEF, myocardial salvage index, microvascular obstruction, and myocardial hemorrhage), with a maximum of 17 points was calculated and included in the multivariable analysis showing that only CMR score (hazard ratio, 1.867 per SD increase [1.311–2.658]; P<0.001) was independently associated with MACE with the highest net reclassification improvement as compared to GRACE score and transthoracic echocardiography-LVEF measurement. Conclusions— CMR score provides incremental prognostic stratification as compared with GRACE score and transthoracic echocardiography-LVEF and may impact the management of patients with ST-segment–elevation myocardial infarction.

Stress Computed Tomographic Perfusion: Are We Ready for the Green Light?

Noninvasive stress tests are commonly used as gatekeepers to invasive coronary angiography (ICA). However, an analysis from the National Cardiovascular Data Registry noted the low diagnostic yield of elective ICA.1 Coronary computed tomographic angiography (cCTA) was introduced as an excellent alternative imaging modality to rule out coronary artery disease (CAD) with low radiation exposure2 and improve prognostic assessment.3 Recent data demonstrated equivalent to improved clinical outcomes with a cCTA-guided diagnostic strategy compared with noninvasive stress tests.4 However, cCTA, particularly in the presence of calcified coronary lesions, overestimates CAD,5 resulting in further testing with increased ionizing radiation exposure, additional costs, and overtreatment of CAD.6 In this regard, new cCTA techniques such as stress computed tomographic perfusion (stress-CTP) have emerged as potential strategies to combine anatomic and functional evaluation in single scan. Recently, Yang et al7 demonstrated that stress-CTP had similar area under the curve (AUC; 0.91 versus 0.95 and 0.88 versus 0.93 per-patient and per-vessel level, respectively) as compared with cardiac magnetic resonance with a trend for better performance when compared with single photon emission computed tomography AUC (0.91 versus 0.87). When compared with invasive fractional flow reserve (FFR) as the reference standard, the sensitivity and specificity of stress-CTP in detecting flow-limiting coronary stenosis were 88% and 80%, respectively.8 Less data are available on the prognostic value of global quantification of left ventricular myocardial perfusion with dynamic stress-CTP. Meinel et al9 recently showed that in 144 patients evaluated with dynamic stress-CTP, global myocardial blood flow (MBF) of <121 mL/100 mL/min was associated with an increased risk for major adverse cardiovascular events (hazard ratio, 2.07; 95% confidence interval,1.12–3.84; P =0.02). The association remained significant after adjusting for age, sex, and clinical …

The New Frontier of Cardiac Computed Tomography Angiography: Fractional Flow Reserve and Stress Myocardial Perfusion

Opinion statementThe increased number of patients with coronary artery disease (CAD) in developed countries is of great clinical relevance and involves a large burden of the healthcare system. The management of these patients is focused on relieving symptoms and improving clinical outcomes. Therefore the ideal test would provide the correct diagnosis and actionable information. To this aim, several non-invasive functional imaging modalities are usually used as gatekeeper to invasive coronary angiography (ICA), but their diagnostic yield remains low with limited accuracy when compared to obstructive CAD at the time of ICA or invasive fractional flow reserve (FFR). Invasive FFR is considered the gold standard for the evaluation of functionally relevant CAD. Therefore, an urgent need for non-invasive techniques that evaluate both the functional and morphological severity of CAD is growing. Coronary computed tomography angiography (CCTA) has emerged as a unique non-invasive technique providing coronary artery anatomic imaging. More recently, the evaluation of FFR with CCTA (FFRCT) has demonstrated high diagnostic performance compared to invasive FFR. Additionally, stress myocardial computed tomography perfusion (CTP) represents a novel tool for the diagnosis of ischemia with high diagnostic accuracy. Compared to nuclear imaging and cardiac magnetic resonance imaging, both FFRCT and stress-CTP, allow us to integrate the anatomical evaluation of coronary arteries with the functional relevance of coronary artery lesions having the potential to revolutionize the diagnostic paradigm of suspected CAD. FFRCT and stress-CTP could be assimilated in diagnostic pathways of patients with stable CAD and will likely result in a decrease of invasive diagnostic procedures and costs. The current review evaluates the technical aspects and clinical experience of FFRCT and stress-CTP in the evaluation of functionally relevant CAD discussing the strengths and weaknesses of each approach.

QT-interval evaluation in primary percutaneous coronary intervention of ST-segment elevation myocardial infarction for prediction of myocardial salvage index

Assessing the efficacy of revascularization therapy in patients with ST-segment elevation myocardial infarction (STEMI) is extremely important in order to guide subsequent management and assess prognosis. We aimed to determine the relationship between corrected QT-interval (QTc) changes on standard sequential ECG and myocardial salvage index in anterior STEMI patients after successful primary percutaneous coronary intervention. Fifty anterior STEMI patients treated by primary percutaneous coronary intervention underwent quantitative ECG analysis and cardiac magnetic resonance. For each patient the difference (ΔQTc) between the QTc of ischemic myocardium (maximum QTc in anterior leads) versus remote myocardium (minimum QTc in inferior leads) during the first six days after STEMI was measured. The QTc in anterior leads was significantly longer than QTc in inferior leads (p<0.0001). At multivariate analysis, ΔQTC and peak troponin I were the only independent predictors for late gadolium enhancement while ΔQTc and left ventricular ejection fraction were independent predictors of myocardial salvage index <60%. The receiver operative curve of ΔQTc showed an area under the curve of 0.77 to predict a myocardial salvage index <0.6. In conclusion, in a subset of patients with a first occurrence of early revascularized anterior STEMI, ΔQTc is inversely correlated with CMR-derived myocardial salvage index and may represent a useful parameter for assessing efficacy of reperfusion therapy.

Real-world clinical utility and impact on clinical decision-making of coronary computed tomography angiography-derived fractional flow reserve: lessons from the ADVANCE Registry

Abstract Aims Non-invasive assessment of stable chest pain patients is a critical determinant of resource utilization and clinical outcomes. Increasingly coronary computed tomography angiography (CCTA) with selective CCTA-derived fractional flow reserve (FFRCT) is being used. The ADVANCE Registry, is a large prospective examination of using a CCTA and FFRCT diagnostic pathway in real-world settings, with the aim of determining the impact of this pathway on decision-making, downstream invasive coronary angiography (ICA), revascularization, and major adverse cardiovascular events (MACE). Methods and results A total of 5083 patients with symptoms concerning for coronary artery disease (CAD) and atherosclerosis on CCTA were enrolled at 38 international sites from 15 July 2015 to 20 October 2017. Demographics, symptom status, CCTA and FFRCT findings, treatment plans, and 90 days outcomes were recorded. The primary endpoint of reclassification between core lab CCTA alone and CCTA plus FFRCT-based management plans occurred in 66.9% [confidence interval (CI): 64.8–67.6] of patients. Non-obstructive coronary disease was significantly lower in ICA patients with FFRCT ≤0.80 (14.4%) compared to patients with FFRCT >0.80 (43.8%, odds ratio 0.19, CI: 0.15–0.25, P < 0.001). In total, 72.3% of subjects undergoing ICA with FFRCT ≤0.80 were revascularized. No death/myocardial infarction (MI) occurred within 90 days in patients with FFRCT >0.80 (n = 1529), whereas 19 (0.6%) MACE [hazard ratio (HR) 19.75, CI: 1.19–326, P = 0.0008] and 14 (0.3%) death/MI (HR 14.68, CI 0.88–246, P = 0.039) occurred in subjects with an FFRCT ≤0.80. Conclusions In a large international multicentre population, FFRCT modified treatment recommendation in two-thirds of subjects as compared to CCTA alone, was associated with less negative ICA, predicted revascularization, and identified subjects at low risk of adverse events through 90 days.

Prognostic relevance of subclinical coronary and carotid atherosclerosis in a diabetic and nondiabetic asymptomatic population

We sought to evaluate the incremental prognostic benefit of carotid artery disease and subclinical coronary artery disease (CAD) features in addition to clinical evaluation in an asymptomatic population.

Impact of a New Adaptive Statistical Iterative Reconstruction (ASIR)-V Algorithm on Image Quality in Coronary Computed Tomography Angiography

RATIONALE AND OBJECTIVES A new postprocessing algorithm named adaptive statistical iterative reconstruction (ASIR)-V has been recently introduced. The aim of this article was to analyze the impact of ASIR-V algorithm on signal, noise, and image quality of coronary computed tomography angiography. MATERIALS AND METHODS Fifty consecutive patients underwent clinically indicated coronary computed tomography angiography (Revolution CT; GE Healthcare, Milwaukee, WI). Images were reconstructed using filtered back projection and ASIR-V 0%, and a combination of filtered back projection and ASIR-V 20%-80% and ASIR-V 100%. Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated for left main coronary artery (LM), left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA) and were compared between the different postprocessing algorithms used. Similarly a four-point Likert image quality score of coronary segments was graded for each dataset and compared. A cutoff value of P < .05 was considered statistically significant. RESULTS Compared to ASIR-V 0%, ASIR-V 100% demonstrated a significant reduction of image noise in all coronaries (P < .01). Compared to ASIR-V 0%, SNR was significantly higher with ASIR-V 60% in LM (P < .01), LAD (P < .05), LCX (P < .05), and RCA (P < .01). Compared to ASIR-V 0%, CNR for ASIR-V ≥60% was significantly improved in LM (P < .01), LAD (P < .05), and RCA (P < .01), whereas LCX demonstrated a significant improvement with ASIR-V ≥80%. ASIR-V 60% had significantly better Likert image quality scores compared to ASIR-V 0% in segment-, vessel-, and patient-based analyses (P < .01). CONCLUSIONS Reconstruction with ASIR-V 60% provides the optimal balance between image noise, SNR, CNR, and image quality.