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.

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.

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.

Impact of Complete Revascularization in the ISCHEMIA Trial.

BACKGROUND: Anatomic complete revascularization (ACR) and functional complete revascularization (FCR) have been associated with reduced death and myocardial infarction (MI) in some prior studies. The impact of complete revascularization (CR) in patients undergoing an invasive (INV) compared with a conservative (CON) management strategy has not been reported. OBJECTIVES: Among patients with chronic coronary disease without prior coronary artery bypass grafting randomized to INV vs CON management in the ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) trial, we examined the following: 1) the outcomes of ACR and FCR compared with incomplete revascularization; and 2) the potential impact of achieving CR in all INV patients compared with CON management. METHODS: ACR and FCR in the INV group were assessed at an independent core laboratory. Multivariable-adjusted outcomes of CR were examined in INV patients. Inverse probability weighted modeling was then performed to estimate the treatment effect had CR been achieved in all INV patients compared with CON management. RESULTS: ACR and FCR were achieved in 43.4% and 58.4% of 1,824 INV patients. ACR was associated with reduced 4-year rates of cardiovascular death or MI compared with incomplete revascularization. By inverse probability weighted modeling, ACR in all 2,296 INV patients compared with 2,498 CON patients was associated with a lower 4-year rate of cardiovascular death or MI (difference -3.5; 95% CI: -7.2% to 0.0%). In comparison, the event rate difference of cardiovascular death or MI for INV minus CON in the overall ISCHEMIA trial was -2.4%. Results were similar but less pronounced with FCR. CONCLUSIONS: The outcomes of an INV strategy may be improved if CR (especially ACR) is achieved. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522).

Cardiovascular and Renal Implications of Myocardial Infarction in the ISCHEMIA-CKD Trial.

BACKGROUND: ISCHEMIA-CKD (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches-Chronic Kidney Disease) reported an initial invasive treatment strategy did not reduce the risk of death or nonfatal myocardial infarction (MI) compared with a conservative treatment strategy in patients with advanced chronic kidney disease, stable coronary disease, and moderate or severe myocardial ischemia. The cumulative frequency of different MI type after randomization and subsequent prognosis have not been reported. METHODS: MI classification was based on the Third Universal Definition for MI. For procedural MI, the primary MI definition used creatine kinase-MB as the preferred biomarker, whereas the secondary MI definition used cTn (cardiac troponin); both definitions included elevated biomarker-only events with higher thresholds than nonprocedural MIs. The cumulative frequency of MI type according to treatment strategy was determined. The association of MI with subsequent all-cause death and new dialysis initiation was assessed by treating MI as a time-dependent covariate. RESULTS: The 3-year incidence of type 1 or 2 MI with the primary MI definition was 11.2% in invasive treatment strategy and 13.6% in conservative treatment strategy (hazard ratio [HR], 0.66 [95% CI, 0.42-1.02]). Procedural MIs were more frequent in invasive treatment strategy and accounted for 9.8% and 28.3% of all MIs with the primary and secondary MI definitions, respectively. Patients had an increased risk of all-cause death after type 1 MI (adjusted HR, 4.35 [95% CI, 2.73-6.93]) and after procedural MI with the primary (adjusted HR, 2.75 [95% CI, 0.99-7.60]) and secondary MI definitions (adjusted HR, 2.91 [95% CI, 1.73-4.88]). Dialysis initiation was increased after a type 1 MI (HR, 6.45 [95% CI, 2.59-16.08]) compared with patients without an MI. CONCLUSIONS: In ISCHEMIA-CKD, the invasive treatment strategy had higher rates of procedural MIs, particularly with the secondary MI definition, and lower rates of type 1 and 2 MIs. Procedural MIs, type 1 MIs, and type 2 MIs were associated with increased risk of subsequent death. Type 1 MI increased the risk of dialysis initiation. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01985360.

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.

BARI 2D: A Reanalysis Focusing on Cardiovascular Events.

OBJECTIVE: To reanalyze the Bypass Angioplasty Revascularization Investigation 2 Diabetes trial using a new composite cardiovascular disease (CVD) outcome to determine how best to treat patients with type 2 diabetes mellitus and stable coronary artery disease. PATIENTS AND METHODS: From January 1, 2001, to November 30, 2008, 2368 patients with type 2 diabetes mellitus and angiographically proven coronary artery disease were randomly assigned to insulin-sensitizing (IS) or insulin-providing (IP) therapy and simultaneously to coronary revascularization (REV) or no or delayed REV (intensive medical therapy [MED]), with all patients receiving intensive medical treatment. The outcome of this analysis was a composite of 8 CVD events. RESULTS: Four-year Kaplan-Meier rates for the composite CVD outcome were 35.8% (95% CI, 33.1%-38.5%) with IS therapy and 41.6% (95% CI, 38.7%-44.5%) with IP therapy (P=.004). Much of this difference was associated with lower in-trial levels of fibrinogen, C-reactive protein, and hemoglobin A1c with IS therapy. Four-year composite CVD rates were 32.7% (95% CI, 30.0%-35.4%) with REV and 44.7% (95% CI, 41.8%-47.6%) with MED (P<.001). A beneficial effect of IS vs IP therapy was present with REV (27.7%; 95% CI, 24.0%-31.4% vs 37.5%; 95% CI, 33.6%-41.4%; P<.001), but not with MED (43.6%; 95% CI, 39.5%-47.7% vs 45.7%; 95% CI, 41.6%-49.8%; P=.37) (homogeneity, P=.05). This interaction between IS therapy and REV was limited to participants preselected for coronary artery bypass grafting (CABG). The lowest composite CVD rates occurred in patients preselected for CABG and assigned to IS therapy and REV (17.3%; 95% CI, 11.8%-22.8%). CONCLUSION: In the Bypass Angioplasty Revascularization Investigation 2 Diabetes trial, the IS treatment strategy and the REV treatment strategy each reduces cardiovascular events. The combination of IS drugs and CABG results in the lowest risk of subsequent CVD events. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00006305.

Clinical and research issues regarding chronic advanced coronary artery disease: part I: Contemporary and emerging therapies.

The following report is based on a working group meeting about advanced coronary artery disease for patients with refractory ischemia who cannot receive revascularization. The aims were to review currently available treatment strategies, define unmet clinical needs, explore clinical trial design issues, and identify promising novel therapeutic targets and approaches for patients with chronic ischemia. The Working Group brought together medical experts in the management of refractory angina with representatives from regulatory agencies, Centers for Medicare and Medicaid Services, and industry. The meeting began with presentations reviewing the limitations of the current medical therapies and revascularization strategies and focused on lessons learned from past therapeutic attempts to optimize outcomes and on what are considered to be the most promising new approaches. Perspectives from clinical experts and from regulatory agencies were juxtaposed against needs and concerns of industry regarding development of new therapeutic strategies. This report presents the considerations and conclusions of the meeting on December 4-5, 2006. This document has been developed as a 2-part article, with contemporary and emerging therapies for advanced coronary artery disease reviewed first. Trial design, end points, and regulatory issues will be discussed in the second part of the article.

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 laboratory­interpreted 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, 0.61­1.30]; severe ischemia HR, 0.83 [95% CI, 0.57­1.21]; P=0.33). Nonfatal MI rates increased with worsening ischemia severity (HR for moderate ischemia, 1.20 [95% CI, 0.86­1.69] versus mild/no ischemia; HR for severe ischemia, 1.37 [95% CI, 0.98­1.91]; P=0.04 for trend, P=NS after adjustment for CAD). Increasing CAD severity was associated with death (HR, 2.72 [95% CI, 1.06­6.98]) and MI (HR, 3.78 [95% CI, 1.63­8.78]) 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.

Impact of complete revascularization in the IschemiaTrial

BACKGROUND: Anatomic complete revascularization (ACR) and functional complete revascularization (FCR) have been associated with reduced death and myocardial infarction (MI) in some prior studies. The impact of complete revascularization (CR) in patients undergoing an invasive (INV) compared with a conservative (CON) management strategy has not been reported. OBJECTIVES: Among patients with chronic coronary disease without prior coronary artery bypass grafting randomized to INV vs CON management in the ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) trial, we examined the following: 1) the outcomes of ACR and FCR compared with incomplete revascularization; and 2) the potential impact of achieving CR in all INV patients compared with CON management. METHODS: ACR and FCR in the INV group were assessed at an independent core laboratory. Multivariable-adjusted outcomes of CR were examined in INV patients. Inverse probability weighted modeling was then performed to estimate the treatment effect had CR been achieved in all INV patients compared with CON management. RESULTS: ACR and FCR were achieved in 43.4% and 58.4% of 1,824 INV patients. ACR was associated with reduced 4-year rates of cardiovascular death or MI compared with incomplete revascularization. By inverse probability weighted modeling, ACR in all 2,296 INV patients compared with 2,498 CON patients was associated with a lower 4-year rate of cardiovascular death or MI (difference -3.5; 95% CI: -7.2% to 0.0%). In comparison, the event rate difference of cardiovascular death or MI for INV minus CON in the overall ISCHEMIA trial was -2.4%. Results were similar but less pronounced with FCR. CONCLUSIONS: The outcomes of an INV strategy may be improved if CR (especially ACR) is achieved. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522).

Stable angina pectoris: antianginal therapies and future directions.

Advances in pharmacotherapy for stable angina have produced a wide choice of drugs with various mechanisms of action, potentially enabling individualized, patient-specific treatment strategies to be developed. In this Review, the various treatment options for patients with stable angina are discussed. Data from randomized, clinical trials of established and novel drugs are reviewed, with particular emphasis on the proposed mechanisms of action, benefits of therapy, and adverse-effect profiles. The role of coronary revascularization in conjunction with optimal medical therapy as a treatment strategy is discussed, although drug therapy might reduce the need for prompt revascularization if the procedure is being considered solely for the purpose of alleviating angina. Finally, trials to investigate stimulation of angiogenesis using growth-factor, gene, and cell therapy are used to illustrate the challenges of chemically inducing the growth of adequate, durable blood vessels.