Baseline Characteristics and Risk Profiles of Participants in the ISCHEMIA Randomized Clinical Trial

Cardiometabolic Co-morbidity Burden and Circulating Biomarkers in Patients With Chronic Coronary Disease in the ISCHEMIA Trials

Cardiometabolic co-morbidities, diabetes (DM), hypertension (HTN), and obesity contribute to cardiovascular disease. Circulating biomarkers facilitate prognostication for patients with cardiovascular disease. We explored the relation between cardiometabolic co-morbidity burden in patients with chronic coronary disease and biomarkers of myocardial stretch, injury, inflammation, and platelet activity. We analyzed participants from the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) trials biorepository with plasma biomarkers (N-terminal probrain natriuretic peptide, high-sensitivity cardiac troponin T, high-sensitivity C-reactive protein, interleukin-6, soluble CD40 ligand, and growth differentiation factor-15) and clinical risk factors (hemoglobin A1c [HbA1c], systolic blood pressure [SBP], and body mass index [BMI]) at baseline. We defined cardiometabolic co-morbidities as DM, HTN, and obesity at baseline. Co-morbidity burden is characterized by the number and severity of co-morbidities. Controlled co-morbidities were defined as HbA1c <7% for those with DM, SBP <130 mm Hg for those with HTN, and BMI <30 kg/m2. Severely uncontrolled was defined as HbA1c ≥8%, SBP ≥160 mm Hg, and BMI ≥35 kg/m2. We performed linear regression analyses to examine the association between co-morbidity burden and log-transformed biomarker levels, adjusting for age, gender, estimated glomerular filtration rate controlled for hemodialysis, and left ventricular ejection fraction. A total of 752 participants (mean age 66 years, 19% women, 84% White) were included in this analysis. Self-reported Black race, current smokers, history of myocardial infarction, and heart failure had a greater cardiometabolic co-morbidity burden. The presence of ≥1 severely uncontrolled co-morbidity was associated with significantly higher baseline levels of high-sensitivity cardiac troponin T, high-sensitivity C-reactive protein, interleukin-6, and growth differentiation factor-15 than participants with no co-morbidities. In conclusion, increasing cardiometabolic co-morbidity burden in patients with chronic coronary disease is associated with higher levels of circulating biomarkers of myocardial injury and inflammation.

Atherosclerosis quantification and cardiovascular risk: the ISCHEMIA trial

BACKGROUND AND AIMS

The aim of this study was to determine the prognostic value of coronary computed tomography angiography (CCTA)-derived atherosclerotic plaque analysis in ISCHEMIA.

METHODS

Atherosclerosis imaging quantitative computed tomography (AI-QCT) was performed on all available baseline CCTAs to quantify plaque volume, composition, and distribution. Multivariable Cox regression was used to examine the association between baseline risk factors (age, sex, smoking, diabetes, hypertension, ejection fraction, prior coronary disease, estimated glomerular filtration rate, and statin use), number of diseased vessels, atherosclerotic plaque characteristics determined by AI-QCT, and a composite primary outcome of cardiovascular death or myocardial infarction over a median follow-up of 3.3 (interquartile range 2.2-4.4) years. The predictive value of plaque quantification over risk factors was compared in an area under the curve (AUC) analysis.

RESULTS

Analysable CCTA data were available from 3711 participants (mean age 64 years, 21% female, 79% multivessel coronary artery disease). Amongst the AI-QCT variables, total plaque volume was most strongly associated with the primary outcome (adjusted hazard ratio 1.56, 95% confidence interval 1.25-1.97 per interquartile range increase [559 mm3]; P = .001). The addition of AI-QCT plaque quantification and characterization to baseline risk factors improved the model's predictive value for the primary outcome at 6 months (AUC 0.688 vs. 0.637; P = .006), at 2 years (AUC 0.660 vs. 0.617; P = .003), and at 4 years of follow-up (AUC 0.654 vs. 0.608; P = .002). The findings were similar for the other reported outcomes.

CONCLUSIONS

In ISCHEMIA, total plaque volume was associated with cardiovascular death or myocardial infarction. In this highly diseased, high-risk population, enhanced assessment of atherosclerotic burden using AI-QCT-derived measures of plaque volume and composition modestly improved event prediction.

Variation in Health Status With Invasive vs Conservative Management of Chronic Coronary Disease

BACKGROUND

The ISCHEMIA trial found that patients with chronic coronary disease randomized to invasive strategy had better health status than those randomized to conservative strategy. It is unclear how best to translate these population-level results to individual patients.

OBJECTIVES

The authors sought to identify patient characteristics associated with health status from invasive and conservative strategies, and develop a prediction algorithm for shared decision-making.

METHODS

One-year disease-specific health status was assessed in ISCHEMIA with the Seattle Angina Questionnaire (SAQ) Summary Score (SAQ SS) and Angina Frequency, Physical Limitations (PL), and Quality of Life (QL) domains (range 0-100, higher = less angina/better health status).

RESULTS

Among 4,617 patients from 320 sites in 37 countries, mean SAQ SS was 74.1 ± 18.9 at baseline and 85.7 ± 15.6 at 1 year. Lower baseline SAQ SS and younger age were associated with better 1-year health status with invasive strategy (P interaction = 0.009 and P interaction = 0.004, respectively). For the individual domains, there were significant treatment interactions for baseline SAQ score (Angina Frequency, PL), age (PL, QL), anterior ischemia (PL), and number of baseline antianginal medications (QL), with more benefit of invasive in patients with worse baseline health status, younger age, anterior ischemia, and on more antianginal medications. Parsimonious prediction models were developed for 1-year SAQ domains with invasive or conservative strategies to support shared decision-making.

CONCLUSIONS

In the management of chronic coronary disease, individual patient characteristics are associated with 1-year health status, with younger age and poorer angina-related health status showing greater benefit from invasive management. This prediction algorithm can support the translation of the ISCHEMIA trial results to individual patients. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522).

Percutaneous coronary intervention versus optimal medical therapy for stable coronary artery disease: An umbrella review

Background

Invasive management of stable coronary artery disease is still a controversial topic. The purpose of this umbrella review was to synthesize systematic reviews (SRs) that evaluate the benefits and harms of percutaneous coronary intervention (PCI) versus optimal medical therapy (OMT) in patients with stable coronary artery disease.

Methods

We systematically searched PubMed/MEDLINE, Embase, and CENTRAL from 2018 to August 7, 2022. We included SRs with meta-analyses of randomized controlled trials (RCTs) that evaluated the question of interest. We assessed the methodological quality of the SRs with the AMSTAR-2 tool. We summarized the results of the outcomes for each SR. We calculated the degree of overlap of the RCTs included in the SRs using the corrected covered area (CCA).

Results

We found 10 SRs with meta-analyses. The SRs included 3 to 15 RCTs. The degree of overlap among the SRs was very high (CCA > 15%). No SR evaluated the certainty of the evidence using the GRADE system and 9 out of 10 had critically low methodological quality. The SRs reported heterogeneous results for the outcomes of all-cause mortality, myocardial infarction, revascularization, and angina. On the other hand, for the outcomes of cardiovascular mortality and stroke, all SRs agreed that there were no differences between PCI and OMT alone.

Conclusions

We found 10 SRs on the use of PCI compared to OMT alone for patients with stable coronary artery disease. However, none had high methodological quality, none evaluated the certainty of the evidence using the GRADE approach, and the results were inconsistent for several outcomes. This variability in evidence may result in divergent clinical decisions for the management of stable coronary artery disease among healthcare professionals. It is necessary to perform a high-quality SR using the GRADE approach to clarify the balance of benefits and harms of PCI.

Sex Differences in Revascularization, Treatment Goals, and Outcomes of Patients With Chronic Coronary Disease: Insights From the ISCHEMIA Trial

BACKGROUND

Women with chronic coronary disease are generally older than men and have more comorbidities but less atherosclerosis. We explored sex differences in revascularization, guideline-directed medical therapy, and outcomes among patients with chronic coronary disease with ischemia on stress testing, with and without invasive management.

METHODS AND RESULTS

The ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) trial randomized patients with moderate or severe ischemia to invasive management with angiography, revascularization, and guideline-directed medical therapy, or initial conservative management with guideline-directed medical therapy alone. We evaluated the primary outcome (cardiovascular death, myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest) and other end points, by sex, in 1168 (22.6%) women and 4011 (77.4%) men. Invasive group catheterization rates were similar, with less revascularization among women (73.4% of invasive-assigned women revascularized versus 81.2% of invasive-assigned men; P<0.001). Women had less coronary artery disease: multivessel in 60.0% of invasive-assigned women and 74.8% of invasive-assigned men, and no ≥50% stenosis in 12.3% versus 4.5% (P<0.001). In the conservative group, 4-year catheterization rates were 26.3% of women versus 25.6% of men (P=0.72). Guideline-directed medical therapy use was lower among women with fewer risk factor goals attained. There were no sex differences in the primary outcome (adjusted hazard ratio [HR] for women versus men, 0.93 [95% CI, 0.77-1.13]; P=0.47) or the major secondary outcome of cardiovascular death/myocardial infarction (adjusted HR, 0.93 [95% CI, 0.76-1.14]; P=0.49), with no significant sex-by-treatment-group interactions.

CONCLUSIONS

Women had less extensive coronary artery disease and, therefore, lower revascularization rates in the invasive group. Despite lower risk factor goal attainment, women with chronic coronary disease experienced similar risk-adjusted outcomes to men in the ISCHEMIA trial.

REGISTRATION

URL: http://wwwclinicaltrials.gov. Unique identifier: NCT01471522.

Biomarkers and cardiovascular events in patients with stable coronary disease in the ISCHEMIA Trials

IMPORTANCE

Biomarkers may improve prediction of cardiovascular events for patients with stable coronary artery disease (CAD), but their importance in addition to clinical tests of inducible ischemia and CAD severity is unknown.

OBJECTIVES

To evaluate the prognostic value of multiple biomarkers in stable outpatients with obstructive CAD and moderate or severe inducible ischemia.

DESIGN AND SETTING

The ISCHEMIA and ISCHEMIA CKD trials randomized 5,956 participants with CAD to invasive or conservative management from July 2012 to January 2018; 1,064 participated in the biorepository.

MAIN OUTCOME MEASURES

Primary outcome was cardiovascular death, myocardial infarction (MI), or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. Secondary outcome was cardiovascular death or MI. Improvements in prediction were assessed by cause-specific hazard ratios (HR) and area under the receiver operating characteristics curve (AUC) for an interquartile increase in each biomarker, controlling for other biomarkers, in a base clinical model of risk factors, left ventricular ejection fraction (LVEF) and ischemia severity. Secondary analyses were performed among patients in whom core-lab confirmed severity of CAD was ascertained by computed cardiac tomographic angiography (CCTA).

EXPOSURES

Baseline levels of interleukin-6 (IL-6), high sensitivity troponin T (hsTnT), growth differentiation factor 15 (GDF-15), N-terminal pro-B-type natriuretic peptide (NT-proBNP), lipoprotein a (Lp[a]), high sensitivity C-reactive protein (hsCRP), Cystatin C, soluble CD 40 ligand (sCD40L), myeloperoxidase (MPO), and matrix metalloproteinase 3 (MMP3).

RESULTS

Among 757 biorepository participants, median (IQR) follow-up was 3 (2-5) years, age was 67 (61-72) years, and 144 (19%) were female; 508 had severity of CAD by CCTA available. In an adjusted multimarker model with hsTnT, GDF-15, NT-proBNP and sCD40L, the adjusted HR for the primary outcome per interquartile increase in each biomarker was 1.58 (95% CI 1.22, 2.205), 1.60 (95% CI 1.16, 2.20), 1.61 (95% 1.22, 2.14), and 1.46 (95% 1.12, 1.90), respectively. The adjusted multimarker model also improved prediction compared with the clinical model, increasing the AUC from 0.710 to 0.792 (P < .01) and 0.714 to 0.783 (P < .01) for the primary and secondary outcomes, respectively. Similar findings were observed after adjusting for core-lab confirmed atherosclerosis severity.

CONCLUSIONS AND RELEVANCE

Among ISCHEMIA biorepository participants, biomarkers of myocyte injury/distension, inflammation, and platelet activity improved cardiovascular event prediction in addition to risk factors, LVEF, and assessments of ischemia and atherosclerosis severity. These biomarkers may improve risk stratification for patients with stable CAD.

Stable Coronary Artery Disease: Who Finally Benefits from Coronary Revascularization in the Modern Era? The ISCHEMIA and Interim ISCHEMIA-EXTEND Analysis

Coronary revascularization is one of the most studied treatment modalities in cardiology; however, there is no consensus among experts about its indications in patients with stable coronary artery disease (SCAD). Contemporary data regarding the role of revascularization in SCAD are in clear conflict with the current European guidelines. This article discusses the main statements of the most significant American and European Guidelines on myocardial revascularization of the last decade and also analyzes the appropriateness of revascularization to improve the prognosis and symptoms in SCAD in the light of new research data, primarily the ISCHEMIA study (NCT01471522) and the ACC/AHA 2021 Revascularization Guidelines based on them. Data on the revascularization in SCAD obtained after the completion of ISCHEMIA (including the interim analysis of ISCHEMIA-EXTEND) and their potential significance are discussed. The results of ISCHEMIA sub-analyses in the most important "controversial" subgroups (3-vessel disease, proximal left anterior descending artery disease, strongly positive stress test, etc.) are reviewed, as are the results of the ISCHEMIA-CKD substudy in patients with severe chronic kidney disease (CKD).

Coronary revascularization for heart failure with coronary artery disease: A systematic review and meta-analysis of randomized trials

AIMS

Coronary artery disease (CAD) is a common cause of heart failure (HF). Whether coronary revascularization improves outcomes in patients with HF receiving guideline-recommended pharmacological therapy (GRPT) remains uncertain; therefore, we conducted a systematic review and meta-analysis of relevant randomized controlled trials (RCTs).

METHODS AND RESULTS

We searched in public databases for RCTs published between 1 January 2001 and 22 November 2022, investigating the effects of coronary revascularization on morbidity and mortality in patients with chronic HF due to CAD. All-cause mortality was the primary outcome. We included five RCTs that enrolled, altogether, 2842 patients (most aged <65 years; 85% men; 67% with left ventricular ejection fraction ≤35%). Overall, compared to medical therapy alone, coronary revascularization was associated with a lower risk of all-cause mortality (hazard ratio [HR] 0.88, 95% confidence interval [CI] 0.79-0.99; p = 0.0278) and cardiovascular mortality (HR 0.80, 95% CI 0.70-0.93; p = 0.0024) but not the composite of hospitalization for HF or all-cause mortality (HR 0.87, 95% CI 0.74-1.01; p = 0.0728). There were insufficient data to show whether the effects of coronary artery bypass graft surgery or percutaneous coronary intervention were similar or differed.

CONCLUSIONS

For patients with chronic HF and CAD enrolled in RCTs, the effect of coronary revascularization on all-cause mortality was statistically significant but neither substantial (HR 0.88) nor robust (upper 95% CI close to 1.0). RCTs were not blinded, which may bias reporting of the cause-specific reasons for hospitalization and mortality. Further trials are required to determine which patients with HF and CAD obtain a substantial benefit from coronary revascularization by either coronary artery bypass graft surgery or percutaneous coronary intervention.

The value of CMR Left ventricular strain analysis in evaluating ICM

The purpose of this article is to investigate the value of cardiac magnetic resonance imaging (CMR) derived left ventricular strain parameters in evaluation of ischemic cardiomyopathy (ICM). Thirty-one ICM patients and nineteen non-cardiomyopathy (non-CM) patients who performed CMR examinations during the same period were selected for this retrospective study. The basic clinical data, CMR left ventricular function parameters, left ventricular strain parameters were compared among the left ventricular ejection fraction (LVEF) preserved ICM group, the LVEF impaired ICM group and the non-CM group. The differences of MyoGCS (-21.9 ± 1.9 vs. -18.9 ± 2.7 P<0.001), MyoGLS (-20.8 ± 2.3 vs. -17.0 ± 2.9 P<0.001) and EndoGLS (-22.2 ± 3.1 vs. -17.6 ± 3.7 P<0.001) between LVEF preserved ICM group and non-CM group were statistically significant, while the differences of left heart function parameters between the two groups were not statistically significant (P > 0.05). The left ventricular strain analysis can be used to assess cardiac functional and morphological alterations in ICM patients prior to changes of left ventricular function parameters, which has high clinical significance.

What Is New in Risk Assessment in Nuclear Cardiology?

Nuclear cardiology techniques allow in-depth evaluation of cardiac patients. A body of literature has established the use of nuclear cardiology. The results obtained with traditional cameras have been reinforced by those obtained with a series of innovations that have revolutionized the field of nuclear cardiology. This article highlights the role of nuclear cardiology in the risk assessment of patients with cardiac disease and sheds light on advancements of nuclear imaging techniques in the cardiovascular field. Patient risk stratification has a key role in modern precision medicine. Nuclear cardiac imaging techniques may quantitatively investigate major disease mechanisms of different cardiac pathologies.

[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.

Ischemia With Nonobstructive Coronary Arteries: Insights From the ISCHEMIA Trial

BACKGROUND

Ischemia with nonobstructive coronary arteries (INOCA) is common clinically, particularly among women, but its prevalence among patients with at least moderate ischemia and the relationship between ischemia severity and non-obstructive atherosclerosis severity are unknown.

OBJECTIVES

The authors investigated predictors of INOCA in enrolled, nonrandomized participants in ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches), sex differences, and the relationship between ischemia and atherosclerosis in patients with INOCA.

METHODS

Core laboratories independently reviewed screening noninvasive stress test results (nuclear imaging, echocardiography, magnetic resonance imaging or nonimaging exercise tolerance testing), and coronary computed tomography angiography (CCTA), blinded to results of the screening test. INOCA was defined as all stenoses <50% on CCTA in a patient with moderate or severe ischemia on stress testing. INOCA patients, who were excluded from randomization, were compared with randomized participants with ≥50% stenosis in ≥1 vessel and moderate or severe ischemia.

RESULTS

Among 3,612 participants with core laboratory-confirmed moderate or severe ischemia and interpretable CCTA, 476 (13%) had INOCA. Patients with INOCA were younger, were predominantly female, and had fewer atherosclerosis risk factors. For each stress testing modality, the extent of ischemia tended to be less among patients with INOCA, particularly with nuclear imaging. There was no significant relationship between severity of ischemia and extent or severity of nonobstructive atherosclerosis on CCTA. On multivariable analysis, female sex was independently associated with INOCA (odds ratio: 4.2 [95% CI: 3.4-5.2]).

CONCLUSIONS

Among participants enrolled in ISCHEMIA with core laboratory-confirmed moderate or severe ischemia, the prevalence of INOCA was 13%. Severity of ischemia was not associated with severity of nonobstructive atherosclerosis. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522).

Phenotype-based management of coronary microvascular dysfunction

40-70% of patients undergoing invasive coronary angiography with signs and symptoms of ischemia are found to have no obstructive coronary artery disease (INOCA). When this heterogeneous group undergo coronary function testing, approximately two-thirds have demonstrable coronary microvascular dysfunction (CMD), which is independently associated with adverse prognosis. There are four distinct phenotypes, or subgroups, each with unique pathophysiological mechanisms and responses to therapies. The clinical phenotypes are microvascular angina, vasospastic angina, mixed (microvascular and vasospastic), and non-cardiac symptoms (reclassification as non-INOCA). The Coronary Vasomotor Disorders International Study Group (COVADIS) have proposed standardized criteria for diagnosis. There is growing awareness of these conditions among clinicians and within guidelines. Testing for CMD can be done using invasive or non-invasive modalities. The CorMicA study advocates the concept of 'functional angiography' to guide stratified medical therapy. Therapies broadly fall into two categories: those that modulate cardiovascular risk and those to alleviate angina. Management should be tailored to the individual, with periodic reassessment for efficacy. Phenotype-based management is a worthy endeavor for both patients and clinicians, aligning with the concept of 'precision medicine' to improve prognosis, symptom burden, and quality of life. Here, we present a contemporary approach to the phenotype-based management of patients with INOCA.

Exercise Stress Echocardiography for Stable Coronary Artery Disease: Succumbed to the Modern Conceptual Revolution or Still Alive and Kicking?

The modern conceptual revolution in managing patients with stable coronary artery disease (CAD), based on improvement in preventive and pharmacological therapy, advocates coronary artery revascularization only for smaller group of patients with refractory angina, poor left ventricular systolic function, or high-risk coronary anatomy. Therefore, our conventional wisdom about stress testing must be questioned within this new and revolutionary paradigm. Exercise stress echocardiography (ESE) is still a well-known technique for assessing known or suspected stable CAD, it is safe, accessible, and well-tolerated, and there is an widespread evidence base. ESE has been remarkably resilient throughout years of innovation in noninvasive cardiology. Its value is not to be determined over the short portion of diagnostic accuracy but mainly through its prognostic value evident in a wide range of patient subsets. It is coming very close to the modern profile of a leading test that should include, in addition to an essential accettable diagnostic and prognostic accuracy, qualities of low cost, no radiation exposure, and minor environmental traces. In this review, we will discuss advantages, diagnostic accuracy, prognostic value in general and special populations, cost-effectiveness, and changes in referral patterns of ESE in the modern era.

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.

Causes of cardiovascular and noncardiovascular death in the ISCHEMIA trial

BACKGROUND

The International Study of Comparative Health Effectiveness with Medical and Invasive Approaches trial demonstrated no overall difference in the composite primary endpoint and the secondary endpoints of cardiovascular (CV) death/myocardial infarction or all-cause mortality between an initial invasive or conservative strategy among participants with chronic coronary disease and moderate or severe myocardial ischemia. Detailed cause-specific death analyses have not been reported.

METHODS

We compared overall and cause-specific death rates by treatment group using Cox models with adjustment for pre-specified baseline covariates. Cause of death was adjudicated by an independent Clinical Events Committee as CV, non-CV, and undetermined. We evaluated the association of risk factors and treatment strategy with cause of death.

RESULTS

Four-year cumulative incidence rates for CV death were similar between invasive and conservative strategies (2.6% vs 3.0%; hazard ratio [HR] 0.98; 95% CI [0.70-1.38]), but non-CV death rates were higher in the invasive strategy (3.3% vs 2.1%; HR 1.45 [1.00-2.09]). Overall, 13% of deaths were attributed to undetermined causes (38/289). Fewer undetermined deaths (0.6% vs 1.3%; HR 0.48 [0.24-0.95]) and more malignancy deaths (2.0% vs 0.8%; HR 2.11 [1.23-3.60]) occurred in the invasive strategy than in the conservative strategy.

CONCLUSIONS

In International Study of Comparative Health Effectiveness with Medical and Invasive Approaches, all-cause and CV death rates were similar between treatment strategies. The observation of fewer undetermined deaths and more malignancy deaths in the invasive strategy remains unexplained. These findings should be interpreted with caution in the context of prior studies and the overall trial results.

Comprehensive Quality-of-Life Outcomes With Invasive Versus Conservative Management of Chronic Coronary Disease in ISCHEMIA

BACKGROUND

ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) compared an initial invasive treatment strategy (INV) with an initial conservative strategy in 5179 participants with chronic coronary disease and moderate or severe ischemia. The ISCHEMIA research program included a comprehensive quality-of-life (QOL) substudy.

METHODS

In 1819 participants (907 INV, 912 conservative strategy), we collected a battery of disease-specific and generic QOL instruments by structured interviews at baseline; at 3, 12, 24, and 36 months postrandomization; and at study closeout. Assessments included angina-related QOL (19-item Seattle Angina Questionnaire), generic health status (EQ-5D), depressive symptoms (Patient Health Questionnaire-8), and, for North American patients, cardiac functional status (Duke Activity Status Index).

RESULTS

Median age was 67 years, 19.2% were female, and 15.9% were non-White. The estimated mean difference for the 19-item Seattle Angina Questionnaire Summary score favored INV (1.4 points [95% CI, 0.2-2.5] over all follow-up). No differences were observed in patients with rare/absent baseline angina (SAQ Angina Frequency score >80). Among patients with more frequent angina at baseline (SAQ Angina Frequency score <80, 744 patients, 41%), those randomly assigned to INV had a mean 3.7-point higher 19-item Seattle Angina Questionnaire Summary score than conservative strategy (95% CI, 1.6-5.8) with consistent effects across SAQ subscales: Physical Limitations 3.2 points (95% CI, 0.2-6.1), Angina Frequency 3.2 points (95% CI, 1.2-5.1), Quality of Life/Health Perceptions 5.3 points (95% CI, 2.8-7.8). For the Duke Activity Status Index, no difference was estimated overall by treatment, but in patients with baseline SAQ Angina Frequency scores <80, Duke Activity Status Index scores were higher for INV (3.2 points [95% CI, 0.6-5.7]), whereas patients with rare/absent baseline angina showed no treatment-related differences. Moderate to severe depression was infrequent at randomization (11.5%-12.8%) and was unaffected by treatment assignment.

CONCLUSIONS

In the ISCHEMIA comprehensive QOL substudy, patients with more frequent baseline angina reported greater improvements in the symptom, physical functioning, and psychological well-being dimensions of QOL when treated with an invasive strategy, whereas patients who had rare/absent angina at baseline reported no consistent treatment-related QOL differences.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01471522.

Does the ISCHEMIA Trial Apply to My Patients?

PURPOSE OF REVIEW

The ISCHEMIA trial demonstrated no difference in myocardial infarction or death in patients with stable coronary disease and moderate or large ischemia territory treated either with invasive revascularization or optimal medical therapy. Whether the findings of the randomized control trial relates to real-world outcomes is uncertain.

RECENT FINDINGS

Contemporary guideline-directed medical therapy has had a significant impact on the prognosis of coronary artery disease. Various observational data appear to indicate limited generalizability of the ISCHEMIA trial in different populations. Further studies are warranted to evaluate the optimal modality of therapy in patients with stable coronary disease and moderate or severe ischemia. The applicability of ISCHEMIA and ISCHEMIA-CKD trials still requires further validation.

Cardiac CT angiography in current practice: An American society for preventive cardiology clinical practice statement✰

In this clinical practice statement, we represent a summary of the current evidence and clinical applications of cardiac computed tomography (CT) in evaluation of coronary artery disease (CAD), from an expert panel organized by the American Society for Preventive Cardiology (ASPC), and appraises the current use and indications of cardiac CT in clinical practice. Cardiac CT is emerging as a front line non-invasive diagnostic test for CAD, with evidence supporting the clinical utility of cardiac CT in diagnosis and prevention. CCTA offers several advantages beyond other testing modalities, due to its ability to identify and characterize coronary stenosis severity and pathophysiological changes in coronary atherosclerosis and stenosis, aiding in early diagnosis, prognosis and management of CAD. This document further explores the emerging applications of CCTA based on functional assessment using CT derived fractional flow reserve, peri‑coronary inflammation and artificial intelligence (AI) that can provide personalized risk assessment and guide targeted treatment. We sought to provide an expert consensus based on the latest evidence and best available clinical practice guidelines regarding the role of CCTA as an essential tool in cardiovascular prevention - applicable to risk assessment and early diagnosis and management, noting potential areas for future investigation.

A meta-analysis of optimal medical therapy with or without percutaneous coronary intervention in patients with stable coronary artery disease

BACKGROUND

Whether percutaneous coronary intervention (PCI) improves clinical outcomes in patients with chronic angina and stable coronary artery disease (CAD) has been a continuing area of investigation for more than two decades. The recently reported results of the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches, the largest prospective trial of optimal medical therapy (OMT) with or without myocardial revascularization, provides a unique opportunity to determine whether there is an incremental benefit of revascularization in stable CAD patients.

METHODS

Scientific databases and websites were searched to find randomized clinical trials (RCTs). Pooled risk ratios were calculated using the random-effects model.

RESULTS

Data from 10 RCTs comprising 12 125 patients showed that PCI, when added to OMT, were not associated with lower all-cause mortality (risk ratios, 0.96; 95% CI, 0.87-1.08), cardiovascular mortality (risk ratios, 0.91; 95% CI, 0.79-1.05) or myocardial infarction (MI) (risk ratios, 0.90; 95% CI, 0.78-1.04) as compared with OMT alone. However, OMT+PCI was associated with improved anginal symptoms and a lower risk for revascularization (risk ratios, 0.52; 95% CI, 0.37-0.75).

CONCLUSIONS

In patient with chronic stable CAD (without left main disease or reduced ejection fraction), PCI in addition to OMT did not improve mortality or MI compared to OMT alone. However, this strategy is associated with a lower rate of revascularization and improved anginal symptoms.

Predictors of Left Main Coronary Artery Disease in the ISCHEMIA Trial

BACKGROUND

Detection of ≥50% diameter stenosis left main coronary artery disease (LMD) has prognostic and therapeutic implications. Noninvasive stress imaging or an exercise tolerance test (ETT) are the most common methods to detect obstructive coronary artery disease, though stress test markers of LMD remain ill-defined.

OBJECTIVES

The authors sought to identify markers of LMD as detected on coronary computed tomography angiography (CTA), using clinical and stress testing parameters.

METHODS

This was a post hoc analysis of ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches), including randomized and nonrandomized participants who had locally determined moderate or severe ischemia on nonimaging ETT, stress nuclear myocardial perfusion imaging, or stress echocardiography followed by CTA to exclude LMD. Stress tests were read by core laboratories. Prior coronary artery bypass grafting was an exclusion. In a stepped multivariate model, the authors identified predictors of LMD, first without and then with stress testing parameters.

RESULTS

Among 5,146 participants (mean age 63 years, 74% male), 414 (8%) had LMD. Predictors of LMD were older age (P < 0.001), male sex (P < 0.01), absence of prior myocardial infarction (P < 0.009), transient ischemic dilation of the left ventricle on stress echocardiography (P = 0.05), magnitude of ST-segment depression on ETT (P = 0.004), and peak metabolic equivalents achieved on ETT (P = 0.001). The models were weakly predictive of LMD (C-index 0.643 and 0.684).

CONCLUSIONS

In patients with moderate or severe ischemia, clinical and stress testing parameters were weakly predictive of LMD on CTA. For most patients with moderate or severe ischemia, anatomical imaging is needed to rule out LMD. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522).

Prevalence of diabetes and impact on cardiovascular events and mortality in patients with chronic coronary syndromes, across multiple geographical regions and ethnicities

Background

In contrast with the setting of acute myocardial infarction, there are limited data regarding the impact of diabetes mellitus on clinical outcomes in contemporary cohorts of patients with chronic coronary syndromes. We aimed to investigate the prevalence and prognostic impact of diabetes according to geographical regions and ethnicity.

Methods and results

CLARIFY is an observational registry of patients with chronic coronary syndromes, enrolled across 45 countries in Europe, Asia, America, Middle East, Australia, and Africa in 2009–2010, and followed up yearly for 5 years. Chronic coronary syndromes were defined by ≥1 of the following criteria: prior myocardial infarction, evidence of coronary stenosis &gt;50%, proven symptomatic myocardial ischaemia, or prior revascularization procedure.

Among 32 694 patients, 9502 (29%) had diabetes, with a regional prevalence ranging from below 20% in Northern Europe to ∼60% in the Gulf countries. In a multivariable-adjusted Cox proportional hazards model, diabetes was associated with increased risks for the primary outcome (cardiovascular death, myocardial infarction, or stroke) with an adjusted hazard ratio of 1.28 (95% confidence interval 1.18, 1.39) and for all secondary outcomes (all-cause and cardiovascular mortality, myocardial infarction, stroke, heart failure, and coronary revascularization). Differences on outcomes according to geography and ethnicity were modest.

Conclusion

In patients with chronic coronary syndromes, diabetes is independently associated with mortality and cardiovascular events, including heart failure, which is not accounted by demographics, prior medical history, left ventricular ejection fraction, or use of secondary prevention medication. This is observed across multiple geographic regions and ethnicities, despite marked disparities in the prevalence of diabetes.

ClinicalTrials identifier

ISRCTN43070564

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.

Role of coronary computed tomography angiography (CTA) post the ISCHEMIA trial: Precision prevention based on coronary CTA-derived coronary atherosclerosis

The International Study of Comparative Health Effectiveness With Medical and Invasive Approaches (ISCHEMIA) trial has been recently published and suggested the importance of the selection of patients at high risk for future cardiovascular disease events and the enhancing optimal medical therapy. In the ISCHEMIA trial, coronary computed tomography angiography (CTA) was performed in most of the patients to exclude high-risk patients and those without obstructive coronary artery disease (CAD) who should not be randomized. Coronary CTA has been widely used as a non-invasive diagnostic modality to assess patients with suspected CAD. Currently, the international guidelines allow use of coronary CTA as a class I recommendation for patients with chest pain. Besides, in the numerous multicenter trials, the emerging role of coronary CTA has proven that it could soon become the standard for monitoring CAD and identifying patients at high risk of future cardiovascular events. In this review article, we summarize the current evidence on coronary CTA and the potential role of coronary CTA after the ISCHEMIA trial for patients with CAD. Risk assessment using detailed CAD data obtained non-invasively and prevention of future cardiovascular events through improved medical care will become increasingly essential for the precision treatment and prevention of CAD in patients.

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.

Comparison of Patients Undergoing Percutaneous Coronary Intervention in Contemporary U.S. Practice With ISCHEMIA Trial Population

OBJECTIVES

The study sought to assess the proportion of patients in modern U.S. interventional practice that fulfilled criteria for enrollment in the ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches) trial.

BACKGROUND

The ISCHEMIA trial, which enrolled patients with stable ischemic heart disease (SIHD), showed that revascularization improved angina symptoms with little effect on death or myocardial infarction.

METHODS

A cross-sectional analysis of the National Cardiovascular Data Registry CathPCI Registry (v5.0), including 1,662 hospitals, was performed. Patients undergoing percutaneous coronary intervention (PCI) for SIHD in routine clinical practice meeting ISCHEMIA trial inclusion criteria and those that did not were evaluated.

RESULTS

During the study period, 388,212 patients underwent PCI for SIHD, comprising 41.88% of all patients undergoing PCI during the study period. Of these, 125,302 (32.28%; 13.52% of all patients undergoing PCI) met criteria for enrollment in the ISCHEMIA trial. Among SIHD patients that did not meet criteria, 71,852 (18.51%) had SIHD with high-risk features (35.2% left main disease, 43.7% left ventricular systolic dysfunction, 16.8% end-stage renal disease), 67,159 (17.3%) had SIHD with negative or low-risk functional testing, and 123,899 (31.92%) either had no stress testing or did not have ischemic burden reported. At the median hospital, 32.1% (interquartile range: 23.5%-40.6%) of SIHD patients met criteria for enrollment in the ISCHEMIA trial, with these patients experiencing lower unadjusted in-hospital mortality rate than comparator groups who met exclusion criteria for the trial (0.11%) (P < 0.01 for all comparisons).

CONCLUSIONS

Among contemporary U.S. patients undergoing PCI for SIHD, 32.28% clearly met enrollment criteria for the ISCHEMIA trial. There was significant variation among individual centers in the proportion of SIHD patients meeting criteria for the ISCHEMIA trial.

Optimum Treatment Strategy in Chronic Coronary Syndromes: the New Trials vs the Current Guidelines

Coronary revascularization is one of the most studied types of interventions in cardiology, but there is no consensus among specialists about the indications for its implementation in patients with chronic coronary syndromes (CCS). The data of recently completed clinical trials on the role of revascularization in CCS clearly contradict the current Guidelines, emphasizing the high effectiveness of modern conservative therapy. This paper discusses the main recommendations of the most significant American and European Guidelines on myocardial revascularization, and also analyzes the appropriateness of revascularization to improve the prognosis and symptoms in chronic coronary syndromes in view of the new research data, primarily the ISCHEMIA study (NCT01471522). Its strengths and limitations are discussed in detail. The data on the expediency of revacularization in CCS, obtained after the completion of ISCHEMIA and its potential significance, as well as subgroup analyses of ISCHEMIA, including in the most important ‘problem’ subgroups (3-vessel disease, proximal LAD disease, severe ischemia on stress test, etc.) are discussed. The paper also discusses the important achievements in modern drug therapy of chronic coronary syndromes, primarily antithrombotic therapy. The data of the COMPASS study (NCT01776424) are discussed, based on which the addition of a second antithrombotic drug – rivaroxaban in a small dose (2.5 mg BID) – is recommended for patients with CCS without atrial fibrillation who have high-risk characteristics. Indications the administration of dual antithrombotic therapy to patients with CCS, comparative results of its various regimens in relation to the prevention of cardiovascular complications, the risk of bleeding and the net clinical effect are given.

Outcomes of Participants With Diabetes in the ISCHEMIA Trials

BACKGROUND

Among patients with diabetes and chronic coronary disease, it is unclear if invasive management improves outcomes when added to medical therapy.

METHODS

The ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) trials (ie, ISCHEMIA and ISCHEMIA-Chronic Kidney Disease) randomized chronic coronary disease patients to an invasive (medical therapy + angiography and revascularization if feasible) or a conservative approach (medical therapy alone with revascularization if medical therapy failed). Cohorts were combined after no trial-specific effects were observed. Diabetes was defined by history, hemoglobin A1c ≥6.5%, or use of glucose-lowering medication. The primary outcome was all-cause death or myocardial infarction (MI). Heterogeneity of effect of invasive management on death or MI was evaluated using a Bayesian approach to protect against random high or low estimates of treatment effect for patients with versus without diabetes and for diabetes subgroups of clinical (female sex and insulin use) and anatomic features (coronary artery disease severity or left ventricular function).

RESULTS

Of 5900 participants with complete baseline data, the median age was 64 years (interquartile range, 57-70), 24% were female, and the median estimated glomerular filtration was 80 mL·min-1·1.73-2 (interquartile range, 64-95). Among the 2553 (43%) of participants with diabetes, the median percent hemoglobin A1c was 7% (interquartile range, 7-8), and 30% were insulin-treated. Participants with diabetes had a 49% increased hazard of death or MI (hazard ratio, 1.49 [95% CI, 1.31-1.70]; P<0.001). At median 3.1-year follow-up the adjusted event-free survival was 0.54 (95% bootstrapped CI, 0.48-0.60) and 0.66 (95% bootstrapped CI, 0.61-0.71) for patients with diabetes versus without diabetes, respectively, with a 12% (95% bootstrapped CI, 4%-20%) absolute decrease in event-free survival among participants with diabetes. Female and male patients with insulin-treated diabetes had an adjusted event-free survival of 0.52 (95% bootstrapped CI, 0.42-0.56) and 0.49 (95% bootstrapped CI, 0.42-0.56), respectively. There was no difference in death or MI between strategies for patients with diabetes versus without diabetes, or for clinical (female sex or insulin use) or anatomic features (coronary artery disease severity or left ventricular function) of patients with diabetes.

CONCLUSIONS

Despite higher risk for death or MI, chronic coronary disease patients with diabetes did not derive incremental benefit from routine invasive management compared with initial medical therapy alone. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01471522.

Outcomes in the ISCHEMIA Trial Based on Coronary Artery Disease and Ischemia Severity

BACKGROUND

The ISCHEMIA trial (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches) postulated that patients with stable coronary artery disease (CAD) and moderate or severe ischemia would benefit from revascularization. We investigated the relationship between severity of CAD and ischemia and trial outcomes, overall and by management strategy.

METHODS

In total, 5179 patients with moderate or severe ischemia were randomized to an initial invasive or conservative management strategy. Blinded, core laboratory-interpreted coronary computed tomographic angiography was used to assess anatomic eligibility for randomization. Extent and severity of CAD were classified with the modified Duke Prognostic Index (n=2475, 48%). Ischemia severity was interpreted by independent core laboratories (nuclear, echocardiography, magnetic resonance imaging, exercise tolerance testing, n=5105, 99%). We compared 4-year event rates across subgroups defined by severity of ischemia and CAD. The primary end point for this analysis was all-cause mortality. Secondary end points were myocardial infarction (MI), cardiovascular death or MI, and the trial primary end point (cardiovascular death, MI, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest).

RESULTS

Relative to mild/no ischemia, neither moderate ischemia nor severe ischemia was associated with increased mortality (moderate ischemia hazard ratio [HR], 0.89 [95% CI, 0.61-1.30]; severe ischemia HR, 0.83 [95% CI, 0.57-1.21]; P=0.33). Nonfatal MI rates increased with worsening ischemia severity (HR for moderate ischemia, 1.20 [95% CI, 0.86-1.69] versus mild/no ischemia; HR for severe ischemia, 1.37 [95% CI, 0.98-1.91]; P=0.04 for trend, P=NS after adjustment for CAD). Increasing CAD severity was associated with death (HR, 2.72 [95% CI, 1.06-6.98]) and MI (HR, 3.78 [95% CI, 1.63-8.78]) for the most versus least severe CAD subgroup. Ischemia severity did not identify a subgroup with treatment benefit on mortality, MI, the trial primary end point, or cardiovascular death or MI. In the most severe CAD subgroup (n=659), the 4-year rate of cardiovascular death or MI was lower in the invasive strategy group (difference, 6.3% [95% CI, 0.2%-12.4%]), but 4-year all-cause mortality was similar.

CONCLUSIONS

Ischemia severity was not associated with increased risk after adjustment for CAD severity. More severe CAD was associated with increased risk. Invasive management did not lower all-cause mortality at 4 years in any ischemia or CAD subgroup. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01471522.

Simplifying the ISCHEMIA trial algorithm for clinical practice: Identifying left main coronary artery disease using coronary artery calcium scans

BACKGROUND

Several recent trials have evaluated invasive versus medical therapy for stable ischemic heart disease. Importantly, patients with significant left main coronary stenosis (LMCS) were excluded from these trials. In the ISCHEMIA trial, these patients were identified by a coronary CT angiogram (CCTA), which adds time, expense, and contrast exposure. We tested whether a coronary artery calcium scan (CACS), a simpler, less expensive test, could replace CCTA to exclude significant LMCS.

METHODS

We hypothesized that patients with ≥50% LMCS would have a LM CACS score > 0. As a corollary, we postulated that a LM CACS = 0 would exclude patients with LMCS. To test this, we searched Intermountain Healthcare's electronic medical records database for all adult patients who had undergone non-contrast cardiac CT for quantitative CACS scoring prior to invasive coronary angiography (ICA). Patients aged <50 and those with a heart transplant were excluded. Cases with incomplete (qualitative) angiographic reports for LMCS and those with incomplete or discrepant LM CACS results were reviewed and reassessed blinded to CACS or ICA findings, respectively.

RESULTS

Among 669 candidate patients with CACS followed by ICA, 36 qualifying patients were identified who had a quantitative CACS score and LMCS ≥ 50%. Their age averaged 71.8 years, and 81% were men. Angiographic LMCS averaged 72% (range 50%-99%). Median time between CACS and ICA was 6 days. Total CACS score averaged 2,383 Agatston Units (AU), range 571-6,636. LM CACS score averaged 197 AU, range 31-610. Importantly, no LMCS patient had a LM CACS score of 0 vs 57% (362/633) of non-LMCS controls (P < .00001).

CONCLUSIONS

Our results support the hypothesis that an easily administered, inexpensive, low radiation CACS can identify a large subset of patients with a very low risk of LMCS who would not have the need for routine CCTA. Using CACS to exclude LMCS may efficiently allow for safe implementation of an initial medical therapy strategy of patients with stable ischemic heart disease in clinical practice. These promising results deserve validation in larger data sets.

Comparison of Days Alive Out of Hospital With Initial Invasive vs Conservative Management: A Prespecified Analysis of the ISCHEMIA Trial

Importance

Traditional time-to-event analyses rate events occurring early as more important than later events, even if later events are more severe, eg, death. Days alive out of hospital (DAOH) adds a patient-focused perspective beyond trial end points.

Objective

To compare DAOH between invasive management and conservative management, including invasive protocol-assigned stays, in the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) randomized clinical trial.

Design, Setting, and Participants

In this prespecified analysis of the ISCHEMIA trial, DAOH was compared between 5179 patients with stable coronary disease and moderate or severe ischemia randomized to invasive management or conservative management. Participants were recruited from 320 sites in 37 countries. Stays included overnight stays in hospital or extended care facility (skilled nursing facility, rehabilitation, or nursing home). DAOH was separately analyzed excluding invasive protocol-assigned procedures. Data were collected from July 2012 to June 2019, and data were analyzed from July 2020 to April 2021.

Interventions

Invasive management with angiography and revascularization if feasible or conservative management, with both groups receiving optimal medical therapy.

Main Outcomes and Measures

The hypothesis was formulated before data lock in July 2020. The primary end point was mean DAOH per patient between randomization and 4 years. Initial stays for invasive protocol-assigned procedures were prespecified to be excluded.

Results

Of 5179 included patients, 1168 (22.6%) were female, and the median (interquartile range) age was 64 (58-70) years. The average DAOH was higher in the conservative management group compared with the invasive management group at 1 month (30.8 vs 28.4 days; P < .001), 1 year (362.2 vs 355.9 days; P < .001), and 2 years (718.4 vs 712.1 days; P = .001). At 4 years, the 2 groups' DAOH were not significantly different (1415.0 vs 1412.2 days; P = .65). In the invasive management group, 2434 of 4002 stays (60.8%) were for protocol-assigned procedures. There were no clear differences at any time point in DAOH when protocol-assigned procedures were excluded from the invasive management group. There were more hospital and extended care stays in the invasive management vs conservative management group during follow-up (4002 vs 1897; P < .001). Excluding protocol-assigned procedures, there were fewer stays in the invasive vs conservative group (1568 vs 1897; P = .001). Cardiovascular stays following the initial assigned procedures were lower in the invasive management group (685 of 4002 [17.1%] vs 1095 of 1897 [57.8%]; P < .001) due to decreased spontaneous myocardial infarction stays (65 [1.6%] vs 123 [6.5%]; P < .001) and unstable angina stays (119 [3.0%] vs 216 [11.4%]; P < .001).

Conclusions and Relevance

DAOH was higher for patients in the conservative management group in the first 2 years but not different at 4 years. DAOH was decreased early in the invasive management group due to protocol-assigned procedures. Hospital stays for myocardial infarction and unstable angina during follow-up were lower in the invasive management group. DAOH provides a patient-focused metric that can be used by clinicians and patients in shared decision-making for management of stable coronary artery disease.

Trial Registration

ClinicalTrials.gov Identifier: NCT01471522.

The New Role of Cardiac Imaging Following the ISCHEMIA Trial

Purpose of Review

This review is aimed at summarizing the recently published ISCHEMIA trial (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) and how its findings may impact cardiac imaging for stable ischemic heart disease (SIHD) moving forward.

Recent Findings

The ISCHEMIA trial compared an initial invasive management strategy with goal of complete coronary revascularization versus an initial medical therapy strategy among stable patients with newly diagnosed moderate to severe myocardial ischemia on non-invasive testing. The trial results showed that an early invasive strategy did not reduce the incidence of major cardiovascular events over 3.2 years of follow-up as compared to optimal medical therapy in patients with SIHD.

Summary

The results of the landmark ISCHEMIA trial solidified the importance of guideline-directed medical therapy and have provided more evidence against the prevailing dogma that moderate to severe ischemia on traditional stress testing mandates coronary revascularization. This trial was not designed to compare different cardiac imaging and stress testing modalities for the assessment of coronary artery disease in patients undergoing their index evaluation for SIHD; however, its design, which included coronary computed tomographic angiography (CCTA) in most patients, and results have generated robust discussion regarding ways to improve non-invasive testing strategies in similar patient populations. We believe that increased utilization of CCTA to identify patients with and without high-risk SIHD, and advanced tests for ischemia, such as positron emission tomography and stress cardiac magnetic resonance imaging, when selected based on individual patient characteristics, may allow for improved decision-making and outcomes.

Defining the prognostic value of [15O]H2O positron emission tomography-derived myocardial ischaemic burden

AIMS

Myocardial ischaemic burden (IB) is used for the risk stratification of patients with coronary artery disease (CAD). This study sought to define a prognostic threshold for quantitative [15O]H2O positron emission tomography (PET)-derived IB.

METHODS AND RESULTS

A total of 623 patients with suspected or known CAD who underwent [15O]H2O PET perfusion imaging were included. The endpoint was a composite of death and non-fatal myocardial infarction (MI). A hyperaemic myocardial blood flow (hMBF) and myocardial flow reserve (MFR)-derived IB were determined. During a median follow-up time of 6.7 years, 62 patients experienced an endpoint. A hMBF IB of 24% and MFR IB of 28% were identified as prognostic thresholds. Patients with a high hMBF or MFR IB (above threshold) had worse outcome compared to patients with a low hMBF IB [annualized event rates (AER): 2.8% vs. 0.6%, P < 0.001] or low MFR IB [AER: 2.4% vs. 0.6%, P < 0.001]. Patients with a concordant high IB had the worst outcome (AER: 3.1%), whereas patients with a concordant low or discordant IB result had similar and low AERs of 0.5% and 0.9% (P = 0.953), respectively. Both thresholds were of prognostic value beyond clinical characteristics, however, only the hMBF IB threshold remained predictive when adjusted for clinical characteristics and combined use of the hMBF and MFR thresholds.

CONCLUSION

A hMBF IB ≥24% was a stronger predictor of adverse outcome than an MFR IB ≥28%. Nevertheless, classifying patients according to concordance of IB result allowed for the identification of low- and high-risk patients.

Natural History of Patients with Ischemia and No Obstructive Coronary Artery Disease: The CIAO-ISCHEMIA Study

Background: Ischemia with no obstructive coronary artery disease (INOCA) is common and has an adverse prognosis. We set out to describe the natural history of symptoms and ischemia in INOCA. Methods: CIAO-ISCHEMIA (Changes in Ischemia and Angina over One year in ISCHEMIA trial screen failures with INOCA) was an international cohort study conducted from 2014-2019 involving angina assessments (Seattle Angina Questionnaire [SAQ]) and stress echocardiograms 1-year apart. This was an ancillary study that included patients with history of angina who were not randomized in the ISCHEMIA trial. Stress-induced wall motion abnormalities were determined by an echocardiographic core laboratory blinded to symptoms, coronary artery disease (CAD) status and test timing. Medical therapy was at the discretion of treating physicians. The primary outcome was the correlation between changes in SAQ Angina Frequency score and change in echocardiographic ischemia. We also analyzed predictors of 1-year changes in both angina and ischemia, and compared CIAO participants with ISCHEMIA participants with obstructive CAD who had stress echocardiography before enrollment, as CIAO participants did. Results: INOCA participants in CIAO were more often female (66% of 208 vs. 26% of 865 ISCHEMIA participants with obstructive CAD, p<0.001), but the magnitude of ischemia was similar (median 4 ischemic segments [IQR 3-5] both groups). Ischemia and angina were not significantly correlated at enrollment in CIAO (p=0.46) or ISCHEMIA stress echocardiography participants (p=0.35). At 1 year, the stress echocardiogram was normal in half of CIAO participants and 23% had moderate or severe ischemia (≥3 ischemic segments). Angina improved in 43% and worsened in 14%. Change in ischemia over one year was not significantly correlated with change in angina (rho=0.029). Conclusions:Improvement in ischemia and improvement in angina were common in INOCA, but not correlated. Our INOCA cohort had a similar degree of inducible wall motion abnormalities to concurrently enrolled ISCHEMIA participants with obstructive CAD. Our results highlight the complex nature of INOCA pathophysiology and the multifactorial nature of angina. Clinical Trial Registration: URL: https://clinicaltrials.gov Unique Identifier: NCT02347215.

Diagnostic Performance of CMR, SPECT, and PET Imaging for the Identification of Coronary Artery Disease: A Meta-Analysis

Background: Myocardial perfusion imaging modalities, such as cardiac magnetic resonance (CMR), single-photon emission computed tomography (SPECT), and positron emission tomography (PET), are well-established non-invasive diagnostic methods to detect hemodynamically significant coronary artery disease (CAD). The aim of this meta-analysis is to compare CMR, SPECT, and PET in the diagnosis of CAD and to provide evidence for further research and clinical decision-making.

Methods: PubMed, Web of Science, EMBASE, and Cochrane Library were searched. Studies that used CMR, SPECT, and/or PET for the diagnosis of CAD were included. Pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio with their respective 95% confidence interval, and the area under the summary receiver operating characteristic (SROC) curve were calculated.

Results: A total of 203 articles were identified for inclusion in this meta-analysis. The pooled sensitivity values of CMR, SPECT, and PET were 0.86, 0.83, and 0.85, respectively. Their respective overall specificity values were 0.83, 0.77, and 0.86. Results in subgroup analysis of the performance of SPECT with ²⁰¹Tl showed the highest pooled sensitivity [0.85 (0.82, 0.88)] and specificity [0.80 (0.75, 0.83)]. ^99mTc-tetrofosmin had the lowest sensitivity [0.76 (0.67, 0.82)]. In the subgroup analysis of PET tracers, results indicated that ¹³N had the lowest pooled sensitivity [0.83 (0.74, 0.89)], and the specificity was the highest [0.91 (0.81, 0.96)].

Conclusion: Our meta-analysis indicates that CMR and PET present better diagnostic performance for the detection of CAD as compared with SPECT.

The ISCHEMIA trial: Implications for non-invasive imaging

Coronary artery disease (CAD) is highly prevalent and constitutes the single most common cause of death worldwide. However, the diagnosis of CAD remains challenging. There are two ways to approach the diagnosis of CAD, namely (1) by a functional non-invasive stress test to detect ischemia (stress echocardiography, stress cardiovascular magnetic resonance, single-photon emission computed tomography, positron emission tomography) or (2) by imaging for stenosis visualization (coronary computed tomography angiography or invasive coronary angiography). There are also two approaches for treatment: medical treatment and revascularization. The International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) trial investigated the outcome differences of patients who had moderate to severe ischemia on stress testing and who, after CT angiography, had ruled out left main stenosis and demonstrated at least 1 coronary artery stenosis exceeding 50%. The patients were randomized to an initially conservative treatment versus immediate revascularization. No difference in hard outcomes was found, but angina relief was more effective in the revascularization group. In this article, we explore the implications of the ISCHEMIA trial for non-invasive testing in suspected CAD.

Complete revascularization in stable multivessel coronary artery disease: A real world analysis from the British Columbia Cardiac Registry

BACKGROUND

More than half of patients undergoing percutaneous coronary intervention (PCI) have multivessel disease (MVD). The prognostic significance of PCI in stable patients has recently been debated, but little data exists about the potential benefit of complete revascularization (CR) in stable MVD. We investigated the prognostic benefit of CR in patients undergoing PCI for stable disease.

METHODS

We compared CR versus incomplete revascularization (IR) in 8,436 patients with MVD. The primary outcome was all-cause mortality at 5 years.

RESULTS

A total of 1,399 patients (17%) underwent CR during the index PCI procedure for stable disease. CR was associated with lower mortality (6.2 vs. 10.7%, p < .001) and lower repeat revascularization at 5 years (12.7 vs. 18.4%, p < .001). Multivariable-adjusted analyses indicated that CR was associated with lower mortality (HR = 0.73, 95% CI: 0.58-0.91, p = .005) and repeat revascularization at 5 years (HR = 0.78, 95% CI: 0.66-0.93, p = .005). These findings were also confirmed in propensity-matched cohorts. Subgroup analyses indicated that CR conferred survival in older patients, male patients, absence of renal disease, greater angina (CCS Class III-IV) and heart failure (NYHA Class III-IV) symptoms, and greater burden of coronary disease. In sensitivity analyses where patients with subsequent repeat revascularization events were excluded, CR remained a strong predictor for lower mortality (HR = 0.69, 95% CI: 0.54-0.89, p = .004).

CONCLUSIONS

In this study of stable patients with MVD, CR was an independent predictor of long-term survival. This benefit was specifically seen in higher risk patient groups and indicates that CR may benefit selected stable patients with MVD.

ISCHEMIA Trial: Key Questions and Answers

A healthy lifestyle, myocardial revascularisation and medical therapy constitute the three pillars for the treatment of ischaemic heart disease. Lifestyle and optimal medical therapy should be used in all cases. However, the selection of cases for revascularisation among stable patients remains controversial. The ISCHEMIA trial compared an early invasive strategy with revascularisation plus optimal medical therapy against initial optimal medical therapy alone with revascularisation reserved for cases in which symptom control was insufficient. The study included over 5,000 patients with stable coronary artery disease and moderate to severe myocardial ischaemia. No differences were found in relevant clinical outcomes, including all-cause mortality, cardiovascular death, MI, heart failure and stroke, over a follow-up of 3.2 years. Conversely, angina control was better in patients with severe symptomatic angina. Following the tradition of all trials comparing medical therapy alone with revascularisation, the ISCHEMIA trial results are controversial, but an analysis of the design and results of the trial offers important information to better understand, evaluate and treat the growing number of patients with stable chronic ischaemic heart disease and moderate to severe myocardial ischaemia.

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.

CT Angiography Followed by Invasive Angiography in Patients With Moderate or Severe Ischemia-Insights From the ISCHEMIA Trial

OBJECTIVES

This study aimed to examine the concordance of coronary computed tomographic angiography (CCTA) assessment of coronary anatomy and invasive coronary angiography (ICA) as the reference standard in patients enrolled in the ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches).

BACKGROUND

Performance of CCTA compared with ICA has not been assessed in patients with very high burdens of stress-induced ischemia and a high likelihood of anatomically significant coronary artery disease (CAD). A blinded CCTA was performed after enrollment to exclude patients with left main (LM) disease or no obstructive CAD before randomization to an initial conservative or invasive strategy, the latter guided by ICA and optimal revascularization.

METHODS

Rates of concordance were calculated on a per-patient basis in patients randomized to the invasive strategy. Anatomic significance was defined as ≥50% diameter stenosis (DS) for both modalities. Sensitivity analyses using a threshold of ≥70% DS for CCTA or considering only CCTA images of good-to-excellent quality were performed.

RESULTS

In 1,728 patients identified by CCTA as having no LM disease ≥50% and at least single-vessel CAD, ICA confirmed 97.1% without LM disease ≥50%, 92.2% with at least single-vessel CAD and no LM disease ≥50%, and only 4.9% without anatomically significant CAD. Results using a ≥70% DS threshold or only CCTA of good-to-excellent quality showed similar overall performance.

CONCLUSIONS

CCTA before randomization in ISCHEMIA demonstrated high concordance with subsequent ICA for identification of patients with angiographically significant disease without LM disease.

Outpatient versus observation/inpatient management of emergency department patients rapidly ruled-out for acute myocardial infarction: Findings from the HIGH-US study

BACKGROUND

The actual Emergency Department (ED) dispositions of patients enrolled in observational studies and meeting criteria for rapid acute myocardial infarction (AMI) rule-out are unknown. Additionally, their presenting clinical profiles, cardiac testing/treatments received, and outcomes have not been reported.

METHODS

Patients in the HIGH-US study (29 sites) that ruled-out for AMI using a high-sensitivity cardiac troponin I 0/1-hour algorithm were evaluated. Clinical characteristics of patients having ED discharge were compared to patients placed in observation or hospital admitted (OBS/ADM). Reports of any OBS/ADM cardiac stress test (CST), cardiac catheterization (Cath) and coronary revascularization were reviewed. One year AMI/death and major adverse cardiovascular event rates were determined.

RESULTS

Of the 1,020 ruled-out AMI patients 584 (57.3%) had ED discharge. The remaining 436 (42.7%) were placed in OBS/ADM. Patients with risk factors for AMI, including personal or family history of coronary artery disease, hypertension, previous stroke or abnormal ECG were more often placed in OBS/ADM. 175 (40.1%) had a CST. Of these 32 (18.3%) were abnormal and 143 (81.7%) normal. Cath was done in 11 (34.3%) of those with abnormal and 13 (9.1%) with normal CST. Of those without an initial CST 85 (32.6%) had Cath. Overall, revascularizations were performed in 26 (6.0%) patients. One-year AMI/death rates were low/similar (P = .553) for the groups studied.

CONCLUSIONS

Rapidly ruled-out for AMI ED patients having a higher clinician perceived risk for new or worsening coronary artery disease and placed in OBS/ADM underwent many diagnostic tests, were infrequently revascularized and had excellent outcomes. Alternate efficient strategies for these patients are needed.

External applicability of the ISCHEMIA trial: an analysis of a prospective, nationwide registry of patients with stable coronary artery disease

AIMS

We sought to assess the proportion of patients eligible for the ISCHEMIA trial and to compare the characteristics and outcomes of these patients with those without ISCHEMIA inclusion or with ISCHEMIA exclusion criteria in a contemporary, nationwide cohort of patients with stable coronary artery disease (CAD).

METHODS AND RESULTS

Among the 5,070 consecutive patients enrolled in the START registry, 4,295 (84.7%) did not fulfil the inclusion criteria (ISCHEMIA-Not Included or ISCHEMIA-Unclassifiable), 582 (11.5%) had exclusion criteria (ISCHEMIA-Excluded), and the remaining 193 (3.8%) were classified as ISCHEMIA-Like. At one year, the incidence of the primary outcome, a composite of death from cardiovascular (CV) causes, myocardial infarction (MI), or hospitalisation for unstable angina and heart failure, was 0.5% in the ISCHEMIA-Like versus 3.3% in other patients (p=0.03). The composite secondary outcome of CV mortality and MI occurred in 0.5% of the ISCHEMIA-Like patients and in 1.4% of the remaining patients (p=0.1).

CONCLUSIONS

In a contemporary real-world cohort of stable CAD patients, only 4% resulted in being eligible for the ISCHEMIA trial. These patients presented an extremely low annual risk of adverse events, especially when compared with other groups of stable CAD patients.