Baseline stress myocardial perfusion imaging results and outcomes in patients with stable ischemic heart disease randomized to optimal medical therapy with or without percutaneous coronary intervention

A Narrative Review of Revascularization in Chronic Coronary Syndrome/Disease: Concepts and Misconceptions

Ischemic heart disease represents a significant global burden of morbidity and mortality. While revascularization strategies are well defined in acute settings, there are uncertainties regarding chronic coronary artery disease treatment. Recent trials have raised doubts about the necessity of revascularization for "stable", chronic coronary syndromes or disease, leading to a shift towards a more conservative approach. However, the issue remains far from settled. In this narrative review, we offer a summary of the most pertinent evidence regarding revascularization for chronic coronary disease, while reflecting on less-often-discussed details of major clinical trials. The cumulative evidence available indicates that there can be a prognostic benefit from revascularization in chronic coronary syndrome patients, provided there is significant ischemia, as demonstrated by either imaging or coronary physiology. Trials that have effectively met this criterion consistently demonstrate a reduction in rates of spontaneous myocardial infarction, which holds both prognostic and clinical significance. The prognostic benefit of revascularization in patients with heart failure with reduced ejection fraction remains especially problematic, with a single contemporary trial favouring surgical revascularization. The very recent publication of a trial focused on revascularizing non-flow-limiting "vulnerable" plaques adds further complexity to the field. The ongoing debates surrounding revascularization in chronic coronary syndromes emphasize the importance of personalized strategies. Revascularization, added to the foundational pillar of medical therapy, should be considered, taking into account symptoms, patient preferences, coronary anatomy and physiology, ischemia tests and intra-coronary imaging.

The diagnostic value of stress echocardiography with limited myocardial ischemia in high-risk patients

BACKGROUND

The diagnostic value of limited myocardial ischemia in DSE is not well known.

OBJECTIVES

We investigated whether myocardial ischemia during dobutamine stress echocardiography (DSE) in 1 apical segment of any of the ventricular walls of the left ventricle relates to the anatomical and functional stenosis of the suppling coronary artery.

METHODS

Our observational, prospective study enrolled 212 patients, symptomatic or asymptomatic, with newly diagnosed limited myocardial ischemia on DSE. Almost 25% of them had already known CAD, while the rest were divided into low-risk and high-risk groups, integrating 1-2 and ≥3 classical cardiovascular risk factors, respectively. After DSE, all patients underwent invasive coronary angiography (ICA) and were followed up for one year. In coronary arteries distributing ischemic area, the calculated stenosis ≥50% and FFR<0.8 were considered anatomically and functionally significant, respectively. In the latter cases, the patients underwent coronary revascularization.

RESULTS

Significant anatomical and functional stenosis of the supplying coronary artery was common among patients with already known CAD (62.5% and 44.5%, respectively) or those without CAD but a high-risk profile (60.2% and 25.6%, respectively). In logistic regression analysis, CAD revascularization was independently determined by an already known CAD, diabetes mellitus, and high-risk profile. During follow-up, 24 patients experienced ACS or new angina episodes, which were associated with diabetes and smoking in univariate analysis.

CONCLUSION

Limited myocardial ischemia may implicate significant anatomical and functional coronary stenosis among individuals with a history of CAD or those without known CAD but a high-risk profile. The prognostic value of our findings requires further investigation.

The ISCHEMIA trial revisited: setting the record straight on the benefits of coronary bypass surgery and the misinterpretation of a landmark trial

OBJECTIVES

The ISCHEMIA trial is a landmark study that has been the subject of heated debate within the cardiovascular community. In this analysis of the ISCHEMIA trial, we aim to set the record straight on the benefits of coronary artery bypass grafting (CABG) and the misinterpretation of this landmark trial. We sought to clarify and reorient this misinterpretation.

METHODS

We herein analyse the ISCHEMIA trial in detail and describe how its misinterpretation has led to an erroneous guideline recommendation downgrading for prognosis-altering surgical therapy in these at-risk patients.

RESULTS

The interim ISCHEMIA trial findings align with previous evidence where CABG reduces the long-term risks of myocardial infarction and mortality in advanced coronary artery disease. The trial outcomes of a significantly lower rate of cardiovascular mortality and a higher rate of non-cardiovascular mortality with the invasive strategy are explained according to landmark evidence.

CONCLUSIONS

The ISCHEMIA trial findings are aligned with previous evidence and should not be used to downgrade recommendations in recent guidelines for the indisputable benefits of CABG.

Diagnostic performance of angiography-derived fractional flow reserve analysis based on bifurcation fractal law for assessing hemodynamic significance of coronary stenosis

OBJECTIVES

Blood flow into the side branch affects the calculation of coronary angiography-derived fractional flow reserve (FFR), called Angio-FFR. Neglecting or improperly compensating for the side branch flow may decrease the diagnostic accuracy of Angio-FFR. This study aims to evaluate the diagnostic accuracy of a novel Angio-FFR analysis that considers the side branch flow based on the bifurcation fractal law.

METHODS

A one-dimensional reduced-order model based on the vessel segment was used to perform Angio-FFR analysis. The main epicardial coronary artery was divided into several segments according to the bifurcation nodes. Side branch flow was quantified using the bifurcation fractal law to correct the blood flow in each vessel segment. In order to verify the diagnostic performance of our Angio-FFR analysis, two other computational methods were taken as control groups: (i) FFR_s: FFR calculated by delineating the coronary artery tree to consider side branch flow, (ii) FFR_n: FFR calculated by just delineating the main epicardial coronary artery and neglecting the side branch flow.

RESULTS

The analysis of 159 vessels from 119 patients showed that our Anio-FFR calculation method had comparable diagnostic accuracy to FFR_s and provided significantly higher diagnostic accuracy than that of FFR_n. In addition, using invasive FFR as a reference, the Pearson correlation coefficients of Angio-FFR and FFRs were 0.92 and 0.91, respectively, while that of FFR_n was only 0.85.

CONCLUSIONS

Our Angio-FFR analysis has demonstrated good diagnostic performance in assessing the hemodynamic significance of coronary stenosis by using the bifurcation fractal law to compensate for side branch flow.

CLINICAL RELEVANCE STATEMENT

Bifurcation fractal law can be used to compensate for side branch flow during the Angio-FFR calculation of the main epicardial vessel. Compensating for side branch flow can improve the ability of Angio-FFR to diagnose stenosis functional severity.

KEY POINTS

• The bifurcation fractal law could accurately estimate the blood flow from the proximal main vessel into the main branch, thus compensating for the side branch flow. • Angiography-derived FFR based on the bifurcation fractal law is feasible to evaluate the target diseased coronary artery without delineating the side branch.

Cardiovascular Disease Risk Factor Profile of Experienced Male Amateur Marathon Runners: A Systematic Review

CONTEXT

Male amateur marathon runners represent a unique subset of the population who may be at increased risk of cardiovascular disease (CVD) due to their underlying risk factors and their involvement in vigorous exercise such as marathon running.

OBJECTIVE

To assess the modifiable risk factors (MRFs) of CVD in experienced male amateur marathon runners and health interventions on CVD risk factors.

DATA SOURCES

CINAHL, Cochrane Library, Embase, Medline, and SPORTDiscus.

STUDY SELECTION

Studies selected according to the inclusion criteria.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 3.

DATA EXTRACTION

The publication dates included were from June 1, 2008 to February 29, 2020.Published primary epidemiological, observational, randomized controlled trial (RCT) and/or non-RCT studies assessing the MRFs of CVD and health interventions on CVD risk factors in male amateur marathon runners aged ≥18 years and written in the English language were included in the review.

RESULTS

Five studies met the inclusion criteria for analysis. These included male amateur marathon runners (n = 862), aged 42 to 77 years. Hypertension, hyperlipidemia, smoking, and alcohol use were MRFs positively associated with an increased risk of coronary atherosclerosis found in a subset of male marathon runners. No studies examined health interventions on CVD risk factors in any of the included studies. All 5 studies were of good quality from the National Heart, Lung, and Blood Institute quality assessment tools used. The risk of bias was low to moderate.

CONCLUSION

There is a paucity of observational studies evaluating the CVD MRFs. Negative lifestyle behaviors exist within this population despite their engagement in physical exercise through marathon running. Marathon running does not negate the long-term effects caused by past negative lifestyle behaviors. This systematic review identifies that this population may not be aware of their possible risk of atherosclerosis and, consequently, CVD.

2023 AHA/ACC/ACCP/ASPC/NLA/PCNA Guideline for the Management of Patients With Chronic Coronary Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2023 AHA/ACC/ACCP/ASPC/NLA/PCNA Guideline for the Management of Patients With Chronic Coronary Disease" provides an update to and consolidates new evidence since the "2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS Guideline for the Diagnosis and Management of Patients With Stable Ischemic Heart Disease" and the corresponding "2014 ACC/AHA/AATS/PCNA/SCAI/STS Focused Update of the Guideline for the Diagnosis and Management of Patients With Stable Ischemic Heart Disease."

METHODS

A comprehensive literature search was conducted from September 2021 to May 2022. Clinical studies, systematic reviews and meta-analyses, and other evidence conducted on human participants were identified that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

This guideline provides an evidenced-based and patient-centered approach to management of patients with chronic coronary disease, considering social determinants of health and incorporating the principles of shared decision-making and team-based care. Relevant topics include general approaches to treatment decisions, guideline-directed management and therapy to reduce symptoms and future cardiovascular events, decision-making pertaining to revascularization in patients with chronic coronary disease, recommendations for management in special populations, patient follow-up and monitoring, evidence gaps, and areas in need of future research. Where applicable, and based on availability of cost-effectiveness data, cost-value recommendations are also provided for clinicians. Many recommendations from previously published guidelines have been updated with new evidence, and new recommendations have been created when supported by published data.

2023 AHA/ACC/ACCP/ASPC/NLA/PCNA Guideline for the Management of Patients With Chronic Coronary Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2023 AHA/ACC/ACCP/ASPC/NLA/PCNA Guideline for the Management of Patients With Chronic Coronary Disease" provides an update to and consolidates new evidence since the "2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS Guideline for the Diagnosis and Management of Patients With Stable Ischemic Heart Disease" and the corresponding "2014 ACC/AHA/AATS/PCNA/SCAI/STS Focused Update of the Guideline for the Diagnosis and Management of Patients With Stable Ischemic Heart Disease."

METHODS

A comprehensive literature search was conducted from September 2021 to May 2022. Clinical studies, systematic reviews and meta-analyses, and other evidence conducted on human participants were identified that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

This guideline provides an evidenced-based and patient-centered approach to management of patients with chronic coronary disease, considering social determinants of health and incorporating the principles of shared decision-making and team-based care. Relevant topics include general approaches to treatment decisions, guideline-directed management and therapy to reduce symptoms and future cardiovascular events, decision-making pertaining to revascularization in patients with chronic coronary disease, recommendations for management in special populations, patient follow-up and monitoring, evidence gaps, and areas in need of future research. Where applicable, and based on availability of cost-effectiveness data, cost-value recommendations are also provided for clinicians. Many recommendations from previously published guidelines have been updated with new evidence, and new recommendations have been created when supported by published data.

Impact of coronary stenting on top of medical therapy and of inclusion of periprocedural infarctions on hard composite endpoints in patients with chronic coronary syndromes: a meta-analysis of randomized controlled trials

INTRODUCTION

Composite endpoints are pivotal when assessing rare outcomes over relatively short follow-ups. Most randomized controlled trials (RCTs) comparing percutaneous coronary intervention (PCI) with stent implantation to optimal medical therapy (OMT) in chronic coronary syndromes (CCS) patients included both hard and soft outcomes in their primary endpoint, with periprocedural myocardial infarctions (MIs) systematically allocated to the PCI arm. We meta-analyzed the above RCTs for composite hard endpoints, with and without periprocedural MIs.

EVIDENCE ACQUISITION

This study is registered in PROSPERO CRD42020166754 and follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Cochrane Collaboration reporting. Patients had inducible ischemia, no left main disease nor severe left ventricular dysfunction.

EVIDENCE SYNTHESIS

Six RCTs involving 10,751 patients followed for a mean of 4.4 years were included. PCI+OMT versus OMT alone was associated with no difference in the two co-primary composite endpoints of all-cause death/MI/stroke and cardiovascular death/MI including all-MIs (IRR 0.99; 95% CI 0.90-1.08 and IRR 0.95; 95% CI 0.83-1.08 respectively). After inclusion of spontaneous rather than all-MIs (i.e., excluding periprocedural MIs), the odds showed benefit of PCI+OMT for both co-primary endpoints (IRR 0.88; 95% CI 0.80-0.97, P<0.01 and IRR 0.81; 95% CI 0.69-0.95, P=0.01 respectively) with numbers needed to treat of 42 in both cases.

CONCLUSIONS

Among CCS patients with inducible myocardial ischemia without severely reduced ejection fraction or left main disease, adding PCI to OMT reduces hard composite outcomes only after exclusion of periprocedural MIs. Continued efforts to define periprocedural MIs reproducibly, to assess their prognostic relevance and to prevent them are warranted.

Complete Versus Incomplete Percutaneous Coronary Intervention-Mediated Revascularization in Patients With Chronic Coronary Syndromes

Multivessel coronary artery disease (CAD) is associated with worse outcomes across the spectrum of clinical presentations. The prognostic implications of completeness of revascularization in CAD patients, especially those with chronic coronary syndromes (CCS), remain highly debated. This is largely due to the use of non-standardized definitions for complete revascularization (CR) and incomplete revascularization (ICR) within previously published studies, lack of randomized clinical data, varying revascularization methods and heterogenous study populations. In particular, the utility and effectiveness of PCI-mediated CR for CCS remains unknown. In this review, we discuss the various definitions used for CR vs. ICR, highlight the rationale for pursuing CR and summarise the current literature regarding the effects of PCI-mediated CR on clinical outcomes in patients with CCS.

Cardiovascular events in patients with coronary artery disease with and without myocardial ischemia: Long-term follow-up

BACKGROUND

After the results of the ISCHEMIA Trial, the role of myocardial ischemia in the prognosis of coronary artery disease (CAD) was under debate. We sought to comparatively evaluate the long-term prognosis of patients with multivessel CAD with or without documented myocardial ischemia.

METHODS

This is a single-center, retrospective, observational cohort study that included patients with CAD obtained from the research protocols database of "The Medicine, Angioplasty or Surgery Study," the MASS Study Group. Patients were stratified according to the presence or absence of myocardial ischemia. Cardiovascular events (overall mortality and myocardial infarction) were tracked from the registry entry up to a median follow-up of 8.7 years. Myocardial ischemia was assessed at baseline by a functional test with or without imaging.

RESULTS

From 1995 to 2018, 2015 patients with multivessel CAD were included. Of these, 1001 presented with conclusive tests at registry entry, 790 (79%) presenting with ischemia and 211 (21%) without ischemia. The median follow-up was 8.7 years (IQR 4.04 to 10.07). The primary outcome occurred in 228 (28.9%) patients with ischemia and in 64 (30.3%) patients without ischemia (p_log-rank=0.60). No significant interaction was observed with the presence of myocardial ischemia and treatment strategies in the occurrence of the combined primary outcome (p_interation=0.14).

CONCLUSIONS

In this sample, myocardial ischemia was not associated with a worse prognosis compared with no ischemia in patients with multivessel CAD. These results refer to debates about the role of myocardial ischemia in the occurrence of cardiovascular events.

[The Revival of the "Ischemic" Approach in the Assessment of Ischemic Heart Disease: Analysis of Major World Research]

This analytical review focuses on large international studies on diagnostics of ischemic heart disease and addresses the role of radionuclide methods in evaluating myocardial perfusion and transient ischemia. Based on the reviewed data, the authors proposed a comprehensive instrumental approach to selecting a tactics for the management of patients with suspected or documented ischemic heart disease and for evaluating their prognosis.

Comparison of Outcomes of Invasive or Conservative Management of Chronic Coronary Disease in Four Randomized Controlled Trials

Revascularization and medical therapy for chronic coronary disease have both evolved significantly over the last 50 years. A total of 4 contemporary randomized controlled trials- Clinical Outcomes Utilizing Revascularization and Aggressive drug Evaluation (COURAGE), Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D), Fractional Flow Reserve versus Angiography for Multivessel Evaluation 2 (FAME 2), and International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA)-have assessed the incremental benefit of revascularization when added to secondary prevention with intensive pharmacologic and lifestyle intervention. We reviewed these 4 seminal studies with the objective of marshaling evidence to better frame how these results should apply to clinical decision making. These studies differed in study design, end points, intensity of treatment, and revascularization techniques. Nevertheless, they all demonstrate similar rates of "hard" clinical events with invasive and conservative management, and varying degrees of benefit in angina-related quality of life with revascularization. In conclusion, although controversy persists concerning the role of revascularization because of differing interpretations of the clinical trial evidence, we contend that instead of being competing management strategies, invasive and conservative approaches are complementary.

Comparison of Characteristics and Outcomes of Veterans With Stable Ischemic Heart Disease Enrolled in the COURAGE Trial Versus the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program

Randomized clinical trials have not demonstrated a survival benefit with percutaneous coronary intervention in stable ischemic heart disease (SIHD). We evaluated the generalizability of the COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) trial findings to the broader population of veterans with SIHD. Veterans who underwent coronary angiography between 2005 and 2013 for SIHD were identified from the Veterans Affairs Clinical Assessment, Reporting and Tracking Program (VA CART). Patient-level comparisons were made between patients from VA CART who met the eligibility criteria for COURAGE and veterans enrolled in COURAGE between 1999 and 2004. All-cause mortality over long-term follow-up was assessed using Cox proportional hazards models. COURAGE-eligible patients from VA CART (n = 59,758) were older, had a higher body mass index, a greater prevalence of co-morbidities, but fewer diseased vessels on index coronary angiography, and were less likely to be on optimal medical therapy at baseline and on 1-year follow-up compared with VA COURAGE participants (n = 968). Patients from VA CART (median follow-up 6.5 years) had higher all-cause mortality (adjusted hazard ratio [aHR] 1.98 [1.61 to 2.43]) than participants from VA COURAGE (median follow-up: 4.6 years). Risks of mortality were greater in the 56.4% patients from CART who were medically managed (aHR 1.94 [1.49 to 2.53]) and in the 43.6% who underwent percutaneous coronary intervention (aHR 1.99 [1.45 to 2.74]), compared with their respective VA COURAGE arms. In conclusion, in this noncontemporaneous patient-level analysis, veterans in the randomized COURAGE trial had more favorable outcomes than the population of veterans with SIHD at large.

The Impact of the ISCHEMIA Trial on Clinical Practice: an Interventionist's Perspective

The International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) trial is the latest in a series of studies evaluating the role of coronary revascularization plus optimal medical therapy (invasive management) as compared to optimal medical therapy alone (conservative management) in the management of patients with stable ischemic heart disease. The "headline" results suggested invasive management did not reduce overall major adverse cardiac events in the intermediate term (~ 3.2 years), although it did sustainably reduce angina. In addition, invasive management reduced spontaneous myocardial infarction, with potentially important beneficial consequences on both long-term mortality and quality of life. This review puts the ISCHEMIA trial into historical context, explores the trial's results and limitations and shows why revascularization remains an important adjunct to optimal medical therapy that should be considered by all patients with stable ischemic heart disease and the physicians who care for them.

Benefit of Early Revascularization Based on Inducible Ischemia and Left Ventricular Ejection Fraction

BACKGROUND

The utility of performing early myocardial revascularization among patients presenting with inducible myocardial ischemia and low left ventricular ejection fraction (LVEF) is currently unknown.

OBJECTIVES

In this study, we sought to assess the relationship between stress-induced myocardial ischemia, revascularization, and all-cause mortality (ACM) among patients with normal vs low LVEF.

METHODS

We evaluated 43,443 patients undergoing stress-rest single-photon emission computed tomography myocardial perfusion imaging from 1998 to 2017. Median follow-up was 11.4 years. Myocardial ischemia was assessed for its interaction between early revascularization and mortality. A propensity score was used to adjust for nonrandomization to revascularization, followed by multivariable Cox modeling adjusted for the propensity score and clinical variables to predict ACM.

RESULTS

The frequency of myocardial ischemia varied markedly according to LVEF and angina, ranging from 6.7% among patients with LVEF ≥55% and no typical angina to 64.0% among patients with LVEF <45% and typical angina (P < 0.001). Among 39,883 patients with LVEF ≥45%, early revascularization was associated with increased mortality risk among patients without ischemia and lower mortality risk among patients with severe (≥15%) ischemia (HR: 0.70; 95% CI: 0.52-0.95). Among 3,560 patients with LVEF <45%, revascularization was not associated with mortality benefit among patients with no or mild ischemia, and was associated with decreased mortality among patients with moderate (10%-14%) (HR: 0.67; 95% CI: 0.49-0.91) and severe (≥15%) (HR: 0.55; 95% CI: 0.38-0.80) ischemia.

CONCLUSIONS

Within this cohort, early myocardial revascularization was associated with a significant reduction in mortality among both patients with normal LVEF and severe inducible myocardial ischemia and patients with low LVEF and moderate or severe inducible myocardial ischemia.

Ischemia Trial: Does the Cardiology Community Need to Pivot or Continue Current Practices?

PURPOSE OF REVIEW

For decades, the standard of care for stable ischemic heart disease (SIHD) has been an ischemia-centric approach based on largely observational data suggesting a survival benefit of revascularization in patients with moderate-or-severe ischemia. In this article, we will objectively review the evolution of the ischemia paradigm, the trial evidence comparing revascularization to medical therapy in SIHD, and what contemporary practice should be in 2022.

RECENT FINDINGS

Randomized trials, including COURAGE and, most recently, the ISCHEMIA trial, have shown no reduction in "hard outcomes" like death and myocardial infarction (MI) in SIHD compared to medical therapy. The trial excluded high-risk patients with left main disease, low ejection fraction (EF) < 35%, and severe unacceptable angina. Irrespective of the severity of ischemia and the extent of coronary artery disease (CAD), revascularization did not offer any prognostic advantage over medical therapy. On the other hand, there was a durable improvement in symptoms. While there are many caveats to the ISCHEMIA trial, the overall strengths of the trial outweigh these limitations. The findings of ISCHEMIA are consistent with previous trials. It is time for the cardiology community to pivot towards medical therapy as the initial step for most patients with SIHD. Physicians should have the "COURAGE" to embrace "ISCHEMIA" and be comfortable with treating ischemia medically.

Revascularization or medical therapy for stable coronary artery disease patients with different degrees of ischemia: a systematic review and meta-analysis of the role of myocardial perfusion

OBJECTIVE

This study explored the best treatment strategies for stable coronary artery disease (SCAD) patients with differing levels of ischemic severity.

METHODS

We conducted a comprehensive search of the PubMed, EMBASE, and Cochrane databases - searching for relevant articles through 4 February 2021. We selected studies comparing different treatments for patients with SCAD who had received ischemia assessments. The primary outcome was death. The secondary outcomes were major adverse cardiovascular events (MACEs) and myocardial infarction (MI).

RESULTS

A total of 11 studies, including 35,607 subjects, were selected for this meta-analysis. Results showed that, compared with medical therapy, revascularization could reduce MACE incidence (odds ratio (OR) 0.73, 95% confidence interval (CI): 0.57-0.94, p < 0.05) in SCAD patients with myocardial ischemia, but that it was not effective for patients without ischemia. For mild ischemia, the incidence of death (OR 0.78, 95% CI: 0.59-1.01, p = 0.063), MACE (OR 0.91, 95% CI: 0.48-1.70, p = 0.762), or MI (OR 1.44, 95% CI: 0.94-2.19, p = 0.093) was the same whether they were treated with revascularization or medical therapy. For moderate to severe ischemia, revascularization reduced the incidence of MACE (OR 0.59, 95% CI: 0.42-0.83, p < 0.05) and MI (OR 0.83, 95% CI: 0.71-0.98, p < 0.05), but the incidence of death (OR 0.73, 95% CI: 0.47-1.12, p = .145) was similar. For SCAD patients with severe ischemia, revascularization may confer survival benefits (OR 0.46, 95% CI: 0.21-1.00, p = 0.05).

CONCLUSION

For SCAD patients with moderate to severe ischemia, revascularization reduces the MACE and MI incidences, but does not change the incidence of death. Evaluation for myocardial ischemia is vital when selecting a therapeutic strategy.

Myocardial viability testing: all STICHed up, or about to be REVIVED?

Patients with ischaemic left ventricular dysfunction frequently undergo myocardial viability testing. The historical model presumes that those who have extensive areas of dysfunctional-yet-viable myocardium derive particular benefit from revascularization, whilst those without extensive viability do not. These suppositions rely on the theory of hibernation and are based on data of low quality: taking a dogmatic approach may therefore lead to patients being refused appropriate, prognostically important treatment. Recent data from a sub-study of the randomized STICH trial challenges these historical concepts, as the volume of viable myocardium failed to predict the effectiveness of coronary artery bypass grafting. Should the Heart Team now abandon viability testing, or are new paradigms needed in the way we interpret viability? This state-of-the-art review critically examines the evidence base for viability testing, focusing in particular on the presumed interactions between viability, functional recovery, revascularization and prognosis which underly the traditional model. We consider whether viability should relate solely to dysfunctional myocardium or be considered more broadly and explore wider uses of viability testingoutside of revascularization decision-making. Finally, we look forward to ongoing and future randomized trials, which will shape evidence-based clinical practice in the future.

Predictors of outcome in the ISCHEMIA-CKD trial: Anatomy versus ischemia

BACKGROUND

The ISCHEMIA-CKD (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches-Chronic Kidney Disease) trial found no advantage to an invasive strategy compared to conservative management in reducing all-cause death or myocardial infarction (D/MI). However, the prognostic influence of angiographic coronary artery disease (CAD) burden and ischemia severity remains unknown in this population. We compared the relative impact of CAD extent and severity of myocardial ischemia on D/MI in patients with advanced chronic kidney disease (CKD).

METHODS

Participants randomized to invasive management with available data on coronary angiography and stress testing were included. Extent of CAD was defined by the number of major epicardial vessels with ≥50% diameter stenosis by quantitative coronary angiography. Ischemia severity was assessed by site investigators as moderate or severe using trial definitions. The primary endpoint was D/MI.

RESULTS

Of the 388 participants, 307 (79.1%) had complete coronary angiography and stress testing data. D/MI occurred in 104/307 participants (33.9%). Extent of CAD was associated with an increased risk of D/MI (P < .001), while ischemia severity was not (P = .249). These relationships persisted following multivariable adjustment. Using 0-vessel disease (VD) as reference, the adjusted hazard ratio (HR) for 1VD was 1.86, 95% confidence interval (CI) 0.94 to 3.68, P = .073; 2VD: HR 2.13, 95% CI 1.10 to 4.12, P = .025; 3VD: HR 4.00, 95% CI 2.06 to 7.76, P < .001. Using moderate ischemia as the reference, the HR for severe ischemia was 0.84, 95% CI 0.54 to 1.30, P = .427.

CONCLUSION

Among ISCHEMIA-CKD participants randomized to the invasive strategy, extent of CAD predicted D/MI whereas severity of ischemia did not.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. These guidelines present an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered. Structure: Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered. Structure: Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. These guidelines present an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated and shared decision-making with patients is recommended.

Implications of the Landmark ISCHEMIA Trial on the Initial Management of High-Risk Patients with Stable Ischemic Heart Disease

PURPOSE OF THE REVIEW

In the decades following the advent of percutaneous coronary intervention, the optimal treatment strategy for managing stable ischemic heart disease has remained a topic of debate. The purpose of this review is to discuss current literature that provides insight into preferred treatment strategies for managing stable coronary artery disease.

RECENT FINDINGS

The COURAGE trial (2007) compared patients with stable coronary artery disease treated with percutaneous coronary intervention plus optimal medical therapy versus optimal medical therapy alone and found no difference in death from any cause and non-fatal myocardial infarction at 4.6 years. The more recent ISCHEMIA trial (2020) compared an initial invasive revascularization strategy with optimal medical therapy to optimal medical therapy alone and similarly found no difference in death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest at 5 years. When applied to a broad population with stable coronary artery disease, evidence suggests there is no benefit to an initial invasive revascularization strategy relative to optimal medical therapy alone. Further investigation is warranted to determine whether there are subgroups of individuals that may benefit from earlier revascularization.

Diagnosis and Management of Stable Angina: A Review

IMPORTANCE

Nearly 10 million US adults experience stable angina, which occurs when myocardial oxygen supply does not meet demand, resulting in myocardial ischemia. Stable angina is associated with an average annual risk of 3% to 4% for myocardial infarction or death. Diagnostic tests and medical therapies for stable angina have evolved over the last decade with a better understanding of the optimal use of coronary revascularization.

OBSERVATIONS

Coronary computed tomographic angiography is a first-line diagnostic test in the evaluation of patients with stable angina due to higher sensitivity and comparable specificity compared with imaging-based stress testing. Moreover, coronary computed tomographic angiography allows detection of nonobstructive atherosclerosis that would not be identified with other noninvasive imaging modalities, improving risk assessment and potentially triggering more appropriate allocation of preventive therapies. Novel therapies treating lipids (proprotein convertase subtilisin/kexin type 9 inhibitors, ezetimibe, and icosapent ethyl) and type 2 diabetes (sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide 1 receptor agonists) have improved cardiovascular outcomes in patients with stable ischemic heart disease when added to usual care. Randomized clinical trials showed no improvement in the rates of mortality or myocardial infarction with revascularization (largely by percutaneous coronary intervention) compared with optimal medical therapy alone, even in the setting of moderate to severe ischemia. In contrast, revascularization provides a meaningful benefit on angina and quality of life compared with antianginal therapies. Measures of the effect of angina on a patient's quality of life should be integrated into the clinic encounter to assist with the decision to proceed with revascularization.

CONCLUSIONS AND RELEVANCE

For patients with stable angina, emphasis should be placed on optimizing lifestyle factors and preventive medications such as lipid-lowering and antiplatelet agents to reduce the risk for cardiovascular events and death. Antianginal medications, such as β-blockers, nitrates, or calcium channel blockers, should be initiated to improve angina symptoms. Revascularization with percutaneous coronary intervention should be reserved for patients in whom angina symptoms negatively influence quality of life, generally after a trial of antianginal medical therapy. Shared decision-making with an informed patient is important for effective treatment of stable angina.

Optimising physiological endpoints of percutaneous coronary intervention

Invasive coronary physiology to select patients for coronary revascularisation has become established in contemporary guidelines for the management of stable coronary artery disease. Compared to revascularisation based on angiography alone, the use of coronary physiology has been shown to improve clinical outcomes and cost efficiency. However, recent data from randomised controlled trials have cast doubt upon the value of ischaemia testing to select patients for revascularisation. Importantly, 20-40% of patients have persistence or recurrence of angina after angiographically successful percutaneous coronary intervention (PCI). This state-of-the-art review is focused on the transitioning role of invasive coronary physiology from its use as a dichotomous test for ischaemia with fixed cut-points, towards its utility for real-time guidance of PCI to optimise physiological results. We summarise the contemporary evidence base for ischaemia testing in stable coronary artery disease, examine emerging indices which allow advanced physiological guidance of PCI, and discuss the rationale and evidence base for post-PCI physiological assessments to assess the success of revascularisation.

Controversies in revascularisation for stable coronary artery disease

Recent randomised controlled trials, such as ISCHEMIA and ORBITA, have overturned most of what we were taught in medical school about hospital procedures considered necessary for patients with stable coronary artery disease. In this article, we discuss what these trials mean for physicians and patients considering revascularisation procedures with the hope of reducing the risk of death or alleviating angina.

Myocardial Ischemia in the Management of Chronic Coronary Artery Disease: Past and Present

For many years, stress-induced myocardial ischemia has been considered important in the management of chronic coronary artery disease. Early evidence focused on the exercise ECG and the Duke treadmill score. In the 1970s, randomized clinical trials, which compared coronary artery bypass surgery to medical therapy, enrolled patients who were very different from contemporary practice and had inconsistent results. Surgery appeared to be of greatest benefit in high-risk patients defined by anatomy (such as left main disease) or stress-induced ischemia. However, randomized clinical trials of revascularization versus contemporary medical therapy over the past 20 years have been surprisingly negative. Nuclear cardiology substudies from these trials reported inconsistent results. Two observational studies from a single-center provided the best evidence for the use of stress-induced ischemia to identify patients who were most likely to benefit from revascularization. The recently completed ISCHEMIA trial (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches) was designed to test the hypothesis that revascularization would improve outcomes in patients with moderate-severe ischemia on stress testing. Unfortunately, 14.2% of the randomized patients had either mild or no ischemia on core lab review. Nearly one-quarter of the patients were randomized on the basis of an exercise ECG without imaging. The negative results of the trial reflect the long-term population decline in coronary artery disease and abnormal stress tests, as well as improvements in patient outcome due to optimal medical therapy. Topics requiring further research are presented. The implications of the trial for the use of both stress imaging and coronary computed tomography angiography in clinical practice are examined.

Lessons Learnt from Recent Trials in Ischemic Heart Disease

Four recently published randomized controlled trials have informed the care of patients with stable ischemic heart disease. The purpose of this clinical focus article is to offer a summary and critical appraisal of the recent evidence. We aim to aid clinicians in the translation of the trial evidence to patient care.

Effect of random deferral of percutaneous coronary intervention in patients with diabetes and stable ischaemic heart disease

BACKGROUND

In stable ischaemic heart disease (SIHD), measurement of fractional flow reserve (FFR) to guide selection of lesions for percutaneous coronary intervention (PCI) reduces death and myocardial infarction (MI) compared with angiographic guidance. However, it is unknown if the improved outcomes are due to avoidance of stenting of physiologically insignificant lesions or are a by-product of placing fewer stents.

METHODS

We developed a Monte Carlo simulation using the PCI strata of the Bypass Angioplasty Revascularization Investigation 2 Diabetes study to investigate how random deferral of PCI impacts outcomes. To simulate deferral, a randomly selected group of patients randomised to PCI were removed and replaced by an equal number of randomly selected patients randomised to intensive medical therapy (IMT) using a random number generator in Python's NumPy module. The primary endpoint was the rate of death or non-fatal MI at 1 year.

RESULTS

Death/MI at 1 year occurred in 8.3% of 798 patients in the PCI group and 5.1% of 807 patients in the IMT control group (p=0.02). Following 10 000 iterations of random replacement of 10%, 20%, 30% or 40% of PCI patients with randomly selected IMT patients, the rate of death/MI at 1 year progressively declined from 8.3% to 8.0%, 7.6%, 7.3% and 7.0%, respectively.

CONCLUSIONS

In this simulation model, random deferral of PCI procedures in SIHD progressively reduced death/MI as the percentage of procedures deferred increases. FFR-guided deferral of PCI may improve outcomes as a result of placing fewer stents and be unrelated to the haemodynamic severity of lesions.

Effectiveness of Clinical, Surgical and Percutaneous Treatment to Prevent Cardiovascular Events in Patients Referred for Elective Coronary Angiography: An Observational Study

Purpose

To ascertain the most appropriate treatment for chronic, stable, coronary artery disease (CAD) in patients submitted to elective coronary angiography.

Patients and Methods

A total of 814 patients included in the prospective cohort study were referred for elective coronary angiography and were followed up on average for 6±1.9 years. Main outcomes were all-cause death, cardiovascular death, non-fatal myocardial infarction (MI) and stroke and late revascularization and their combinations as major adverse cardiac and cerebral events (MACCE): MACCE-1 included cardiovascular death, nonfatal MI, and stroke; MACCE-2 was MACCE-1 plus late revascularization. Survival curves and adjusted Cox proportional hazard models were used to explore the association between the type of treatment and outcomes.

Results

All-cause death was lower in participants submitted to percutaneous coronary intervention (PCI) (0.41, 0.16-1.03, P=0.057) compared to medical treatment (MT). Coronary-artery bypass grafting (CABG) had an overall trend for poorer outcomes: cardiovascular death 2.53 (0.42-15.10), combined cardiovascular death, nonfatal MI, and stroke 2.15 (0.73-6.31) and these events plus late revascularization (2.17, 0.86-5.49). The corresponding numbers for PCI were 0.27 (0.05-1.43) for cardiovascular death, 0.77 (0.32-1.84) for combined cardiovascular death, nonfatal MI, and stroke and 2.35 (1.16-4.77) with the addition of late revascularization. These trends were not influenced by baseline blood pressure, left ventricular ejection fraction and previous MI. Patients with diabetes mellitus had a significantly higher risk of recurrent revascularization when submitted to PCI than CABG.

Conclusion

Patients with confirmed CAD in elective coronary angiography do not have a better prognosis when submitted to CABG comparatively to medical treatment. Patients treated with PCI had a trend for the lower incidence of combined cardiovascular events, at the expense of additional revascularization procedures. Patients without significant CAD had a similar prognosis than CAD patients treated with medical therapy.

ACR Appropriateness Criteria® Chest Pain-Possible Acute Coronary Syndrome

Chest pain is a frequent cause for emergency department visits and inpatient evaluation, with particular concern for acute coronary syndrome as an etiology, since cardiovascular disease is the leading cause of death in the United States. Although history-based, electrocardiographic, and laboratory evaluations have shown promise in identifying coronary artery disease, early accurate diagnosis is paramount and there is an important role for imaging examinations to determine the presence and extent of anatomic coronary abnormality and ischemic physiology, to guide management with regard to optimal medical therapy or revascularization, and ultimately to thereby improve patient outcomes. A summary of the various methods for initial imaging evaluation of suspected acute coronary syndrome is outlined in this document. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Effect of Coronary Anatomy and Myocardial Ischemia on Long-Term Survival in Patients with Stable Ischemic Heart Disease

Background The severity of coronary artery disease (CAD) and of ischemia are evaluated to guide therapy, but their relative prognostic importance remains uncertain. Accordingly, we sought to clarify their association with long-term survival in the COURAGE trial (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation). Methods and Results Survival data from after the original trial period ended was obtained at 15 Veterans Affairs sites and 13 of 18 United States non-Veterans Affairs sites. Date of death was obtained from the Veterans Affairs system-wide Corporate Data Warehouse and the National Death Index. Of the original 2287 patients in COURAGE, 1370 (60%) had both stress perfusion imaging and quantitative coronary angiography available, with extended survival evaluated in 767 subjects. Survival was calculated by the Kaplan-Meier method, and a Cox proportional-hazards model adjusted for baseline differences. There were 369 all-cause deaths during a median follow-up of 7.9 years (range, 0-15 years). The number of coronary arteries diseased predicted survival (HR, 1.25; 95% CI, 1.09-1.43), whereas severity of ischemia did not (HR, 0.99; 95% CI, 0.80-1.22). Percutaneous coronary intervention did not offer a survival advantage over optimal medical therapy (HR, 0.95; 95% CI, 0.77-1.16) and there was no interaction between therapeutic strategy and number of coronary arteries diseased or severity of ischemia. In fully adjusted models, the number of coronary arteries diseased was not associated with increased mortality. Conclusions In univariate analysis, the number of coronary arteries diseased predicted long-term mortality, but severity of ischemia did not. Adjusted for baseline variables, neither assessment approach predicted mortality. Overall, there was no survival benefit from percutaneous coronary intervention in any subset defined by either angiographic or ischemic severity. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT00007657.

Evaluation of Myocardial Ischemia Using Coronary Computed Tomography Angiography in Patients with Stable Angina

안정형 협심증 환자에서 관상동맥질환의 치료 여부를 결정하고 임상 결과를 예측하기 위해서는 심근허혈의 평가가 중요하다. 현재 심근허혈 진단의 표준검사법으로 분획혈류예비력 검사법이 인정되나 침습적 검사라는 제한점이 있다. 또한, 관상동맥 전산화단층촬영은 형태적인 관상동맥질환 진단에 유용한 방법으로 정립되었지만, 혈역학적으로 유의한 협착에 의한 심근허혈 진단에는 한계가 있다. 최근 이러한 문제를 해결하고자 관상동맥 전산화단층촬영 영상을 기반으로 측정한 관상동맥 죽상경화판의 정량화, 심근관류, 그리고 심근 분획혈류예비력을 이용한 연구들이 진행되어 왔고, 그 진단적 가치를 점차 인정받고 있다. 본 종설에서는 심근허혈진단과 관련된 관상동맥 전산화단층촬영 혈관조영술의 여러 영상기법들에 대해서 알아보고자 한다.

Dobutamine Stress Echocardiography Ischemia as a Predictor of the Placebo-Controlled Efficacy of Percutaneous Coronary Intervention in Stable Coronary Artery Disease: The Stress Echocardiography-Stratified Analysis of ORBITA

BACKGROUND

Dobutamine stress echocardiography is widely used to test for ischemia in patients with stable coronary artery disease. In this analysis, we studied the ability of the prerandomization stress echocardiography score to predict the placebo-controlled efficacy of percutaneous coronary intervention (PCI) within the ORBITA trial (Objective Randomised Blinded Investigation With Optimal Medical Therapy of Angioplasty in Stable Angina).

METHODS

One hundred eighty-three patients underwent dobutamine stress echocardiography before randomization. The stress echocardiography score is broadly the number of segments abnormal at peak stress, with akinetic segments counting double and dyskinetic segments counting triple. The ability of prerandomization stress echocardiography to predict the placebo-controlled effect of PCI on response variables was tested by using regression modeling.

RESULTS

At prerandomization, the stress echocardiography score was 1.56±1.77 in the PCI arm (n=98) and 1.61±1.73 in the placebo arm (n=85). There was a detectable interaction between prerandomization stress echocardiography score and the effect of PCI on angina frequency score with a larger placebo-controlled effect in patients with the highest stress echocardiography score (P_interaction=0.031). With our sample size, we were unable to detect an interaction between stress echocardiography score and any other patient-reported response variables: freedom from angina (P_interaction=0.116), physical limitation (P_interaction=0.461), quality of life (P_interaction=0.689), EuroQOL 5 quality-of-life score (P_interaction=0.789), or between stress echocardiography score and physician-assessed Canadian Cardiovascular Society angina class (P_interaction=0.693), and treadmill exercise time (P_interaction=0.426).

CONCLUSIONS

The degree of ischemia assessed by dobutamine stress echocardiography predicts the placebo-controlled efficacy of PCI on patient-reported angina frequency. The greater the downstream stress echocardiography abnormality caused by a stenosis, the greater the reduction in symptoms from PCI.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02062593.

Current approach to the diagnosis of atherosclerotic coronary artery disease: more questions than answers

Despite its commonality in routine clinical practice, the approach to a diagnosis of atherosclerotic coronary artery disease remains complex and, in part, contentious. The traditional dogma linking ischaemia to hard clinical outcomes has been questioned and reframed over the years; rather than being a predictor of hard clinical outcomes, the degree of ischaemia may simply be a marker of atherosclerotic disease burden. A renewed interest in the imaging of plaque burden has spawned the contemporary role of CT imaging for not only diagnosis and prognosis, but also for dictating downstream management. As the technology develops and evidence expands, decisions on investigative modalities remain centred around patient factors, local availability, test performance and cost. This review summarizes the available methods for diagnosis in the symptomatic patient and provides an overview of the current evidence behind functional and anatomical approaches.

Extent of Myocardial Ischemia on Positron Emission Tomography and Survival Benefit With Early Revascularization

BACKGROUND

Prior studies with single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) have shown a survival benefit with early revascularization in patients with >10% to 12.5% ischemic myocardium. The relationship among positron emission tomography (PET)-derived extent of ischemia, early revascularization, and survival is unknown.

OBJECTIVES

The purpose of this study was to evaluate the association among percent ischemia on PET MPI, revascularization, and survival.

METHODS

A total of 16,029 unique consecutive patients who were undergoing Rubidium-82 rest-stress PET MPI from 2010 to 2016 were included. Patients with known cardiomyopathy and nondiagnostic perfusion results were excluded. Percent ischemic myocardium was estimated from a 17-segment model. Propensity scoring was used to account for nonrandomized referral to early revascularization (90 days of PET). A Cox model was developed, adjusting for propensity scores for early revascularization and percent ischemia, and an interaction between ischemia and early revascularization was tested.

RESULTS

Median follow-up was 3.7 years. Overall, 1,277 (8%) patients underwent early revascularization and 2,493 (15.6%) died (738 cardiac). Nearly 37% of patients (n = 5,902) had ischemia, with 13.5% (n = 2,160) having ≥10%. In propensity-adjusted analyses, there was a significant interaction between ischemia and early revascularization (p < 0.001 for all-cause and cardiac death), such that patients with greater ischemia had improved survival with early revascularization, with a potential ischemia threshold at 5% (upper limit 95% confidence interval at 10%). There was no differential association between ischemia and early revascularization on death based on history of known coronary artery disease (interaction p = 0.72).

CONCLUSIONS

In a contemporary cohort of patients undergoing PET MPI, patients with greater ischemia had a survival benefit from early revascularization. On exploratory analyses, this threshold was lower than that previously reported for SPECT. These findings require future validation in prospective cohorts or trials.

Association Between Stress Testing-Induced Myocardial Ischemia and Clinical Events in Patients With Multivessel Coronary Artery Disease

IMPORTANCE

The long-term prognostic implications of myocardial ischemia documented during stress testing in patients with multivessel coronary artery disease (CAD) are unclear.

OBJECTIVE

To assess whether documented stress testing-induced myocardial ischemia is associated with major adverse cardiovascular events or ventricular function changes in patients with stable multivessel CAD.

DESIGN, SETTING, AND PARTICIPANTS

A prospective cohort study was conducted using data from a single-center randomized clinical trial (Medicine, Angioplasty, or Surgery Study [MASS] II) to examine the association of myocardial ischemia documented during stress testing at baseline with cardiovascular events and ventricular function changes during follow-up. Participants were previously randomized (May 1, 1995, to May 31, 2000) to medical therapy, percutaneous coronary intervention with bare metal stents, or coronary artery bypass grafting. Event-free survival was estimated by the Kaplan-Meier method, and multivariable Cox regression models were calculated to assess the association between ischemia and the primary composite end point. The vital status was determined on February 28, 2011. Data were analyzed from February 1, 2016, to April 1, 2017.

MAIN OUTCOMES AND MEASURES

Cardiovascular events (overall mortality, myocardial infarction, and revascularization for refractory angina) were tracked from the time of randomization to the end of the 10-year follow-up (mean [SD] duration, 11.4 [4.3] years). Myocardial ischemia was assessed at baseline and at 1-year intervals by exercise stress testing, and ventricular function (left ventricular ejection fraction) was assessed by echocardiography at baseline and after 10 years. Patients with documented ischemia were compared with those without ischemia regarding the outcomes and changes in ventricular function.

RESULTS

Of 611 participants, 535 underwent exercise stress testing at baseline: 270 with documented ischemia and 265 without. Of these 535 patients, 373 (69.7%) were men, and the mean (SD) age for the entire cohort was 59.7 (9.2) years. No association was found between the presence of ischemia at baseline and survival free of combined cardiovascular events (hazard ratio, 1.00; 95% CI, 0.80-1.27; P = .95) after multivariable adjustment that included CAD initial randomized treatments. In addition, among 320 patients who underwent echocardiographic evaluation, the slight decline in left ventricular ejection fraction after 10 years was similar in both groups (median [SD] difference, -4.9% [18.7%] vs -6.6% [20.0%], respectively, for groups with and without ischemia; P = .97).

CONCLUSIONS AND RELEVANCE

In this study, regardless of the therapeutic strategy applied, the presence of documented myocardial ischemia did not appear to be associated with an increased occurrence of major adverse cardiovascular events or changes in ventricular function in patients with multivessel CAD during a long-term follow-up.