Outcomes With Intermediate Left Main Disease: Analysis From the ISCHEMIA Trial.

BACKGROUND: Patients with significant (≥50%) left main disease (LMD) have a high risk of cardiovascular events, and guidelines recommend revascularization to improve survival. However, the impact of intermediate LMD (stenosis, 25%-49%) on outcomes is unclear. METHODS: Randomized ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches) participants who underwent coronary computed tomography angiography at baseline were categorized into those with (25%-49%) and without (<25%) intermediate LMD. The primary outcome was a composite of cardiovascular mortality, myocardial infarction (MI), or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. The primary quality of life outcome was the Seattle Angina Questionnaire summary score. RESULTS: Among the 3699 participants who satisfied the inclusion criteria, 962 (26%) had intermediate LMD. Among invasive strategy participants with intermediate LMD on coronary computed tomography angiography, 49 (7.0%) had significant (≥50% stenosis) left main stenosis on invasive angiography. Patients with intermediate LMD had a higher risk of cardiovascular events in the unadjusted but not in the fully adjusted model compared with those without intermediate LMD. An invasive strategy increased procedural MI and decreased nonprocedural MI with no significant difference for other outcomes including the primary end point. There was no meaningful heterogeneity of treatment effect based on intermediate LMD status except for nonprocedural MI for which there was a greater absolute reduction with invasive management in the intermediate LMD group (-6.4% versus -2.0%; Pinteraction=0.049). The invasive strategy improved angina-related quality of life and the benefit was durable throughout follow-up without significant heterogeneity based on intermediate LMD status. CONCLUSIONS: In the ISCHEMIA trial, there was no meaningful heterogeneity of treatment benefit from an invasive strategy regardless of intermediate LMD status except for a greater absolute risk reduction in nonprocedural MI with invasive management in those with intermediate LMD. An invasive strategy increased procedural MI, reduced nonprocedural MI, and improved angina-related quality of life. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01471522.

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.

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.

Initial invasive versus conservative management of stable ischemic heart disease patients with a history of heart failure or left ventricular dysfunction: Insights from the ISCHEMIA trial

Background: It is unknown whether an initial invasive strategy in patients with stable ischemic heart disease and at least moderate ischemia improves outcomes in patients with a history of heart failure (HF) or left ventricular dysfunction (LVD) when EF >35%, but <45%. Methods: Among 5179 participants randomized into the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA), all of whom had LVEF >35%, we compared cardiovascular outcomes by treatment strategy in those with a history of HF or LV dysfunction (HF/LVD) at baseline versus those without HF/LVD. Median follow up was 3.2 years. Results: There were 398 (7.7%) participants with HF/LVD at baseline of whom 177 had HF/LVEF>45%, 28 had HF/LVEF 35-45% and 193 had LVEF 35-45% but no prior history of HF. HF/LVD was associated with more comorbidities at baseline, particularly prior myocardial infarction (MI), stroke and hypertension. Compared to those without HF/LVD, those with HF/LVD were more likely to experience a primary outcome composite of cardiovascular death, nonfatal MI, or hospitalization for unstable angina, HF, or resuscitated cardiac arrest; four-year cumulative incidence rate (22.7% vs. 13.8%), cardiovascular death or MI (19.7% vs. 12.3%), and all-cause death or HF (15.0% vs. 6.9%). Those with HF/LVD randomized to the invasive versus conservative strategy had a lower rate of the primary outcome (17.2% vs. 29.3%, difference in 4- year event rate -12.1%; 95% CI: -22.6, -1.6%), whereas those without HF/LVD did not (13.0% vs. 14.6%, difference in 4-year event rate -1.6%; 95% CI: -3.8%, 0.7%; p-interaction = 0.055). A similar differential effect was seen for the primary outcome, all-cause mortality, and CV mortality when invasive versus conservative strategy associated outcomes were analyzed with LVEF as a continuous variable for those with and without prior HF. Conclusions: ISCHEMIA trial participants with stable ischemic heart disease and at least moderate ischemia with a history of HF or LVD were at increased risk for the primary outcome. In the small, high-risk subgroup with HF and LVEF 35-45%, an initial invasive approach was associated with a better event-free survival. This result should be considered hypothesis generating.

Initial Invasive Versus Conservative Management of Stable Ischemic Heart Disease in Patients With a History of Heart Failure or Left Ventricular Dysfunction: Insights From the ISCHEMIA Trial.

BACKGROUND: Whether an initial invasive strategy in patients with stable ischemic heart disease and at least moderate ischemia improves outcomes in the setting of a history of heart failure (HF) or left ventricular dysfunction (LVD) when ejection fraction is ≥35% but <45% is unknown. METHODS: Among 5179 participants randomized into ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches), all of whom had left ventricular ejection fraction (LVEF) ≥35%, we compared cardiovascular outcomes by treatment strategy in participants with a history of HF/LVD at baseline versus those without HF/LVD. Median follow-up was 3.2 years. RESULTS: There were 398 (7.7%) participants with HF/LVD at baseline, of whom 177 had HF/LVEF >45%, 28 HF/LVEF 35% to 45%, and 193 LVEF 35% to 45% but no history of HF. HF/LVD was associated with more comorbidities at baseline, particularly previous myocardial infarction, stroke, and hypertension. Compared with patients without HF/LVD, participants with HF/LVD were more likely to experience a primary outcome composite of cardiovascular death, nonfatal myocardial infarction, or hospitalization for unstable angina, HF, or resuscitated cardiac arrest (4-year cumulative incidence rate, 22.7% versus 13.8%; cardiovascular death or myocardial infarction, 19.7% versus 12.3%; and all-cause death or HF, 15.0% versus 6.9%). Participants with HF/LVD randomized to the invasive versus conservative strategy had a lower rate of the primary outcome (17.2% versus 29.3%; difference in 4-year event rate, -12.1% [95% CI, -22.6 to -1.6%]), whereas those without HF/LVD did not (13.0% versus 14.6%; difference in 4-year event rate, -1.6% [95% CI, -3.8% to 0.7%]; P interaction = 0.055). A similar differential effect was seen for the primary outcome, all-cause mortality, and cardiovascular mortality when invasive versus conservative strategy-associated outcomes were analyzed with LVEF as a continuous variable for patients with and without previous HF. CONCLUSIONS: ISCHEMIA participants with stable ischemic heart disease and at least moderate ischemia with a history of HF or LVD were at increased risk for the primary outcome. In the small, high-risk subgroup with HF and LVEF 35% to 45%, an initial invasive approach was associated with better event-free survival. This result should be considered hypothesis-generating. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01471522.

Initial Invasive or Conservative Strategy for Stable Coronary Disease.

BACKGROUND: Among patients with stable coronary disease and moderate or severe ischemia, whether clinical outcomes are better in those who receive an invasive intervention plus medical therapy than in those who receive medical therapy alone is uncertain. METHODS: We randomly assigned 5179 patients with moderate or severe ischemia to an initial invasive strategy (angiography and revascularization when feasible) and medical therapy or to an initial conservative strategy of medical therapy alone and angiography if medical therapy failed. The primary outcome was a composite of death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. A key secondary outcome was death from cardiovascular causes or myocardial infarction. RESULTS: Over a median of 3.2 years, 318 primary outcome events occurred in the invasive-strategy group and 352 occurred in the conservative-strategy group. At 6 months, the cumulative event rate was 5.3% in the invasive-strategy group and 3.4% in the conservative-strategy group (difference, 1.9 percentage points; 95% confidence interval [CI], 0.8 to 3.0); at 5 years, the cumulative event rate was 16.4% and 18.2%, respectively (difference, -1.8 percentage points; 95% CI, -4.7 to 1.0). Results were similar with respect to the key secondary outcome. The incidence of the primary outcome was sensitive to the definition of myocardial infarction; a secondary analysis yielded more procedural myocardial infarctions of uncertain clinical importance. There were 145 deaths in the invasive-strategy group and 144 deaths in the conservative-strategy group (hazard ratio, 1.05; 95% CI, 0.83 to 1.32). CONCLUSIONS: Among patients with stable coronary disease and moderate or severe ischemia, we did not find evidence that an initial invasive strategy, as compared with an initial conservative strategy, reduced the risk of ischemic cardiovascular events or death from any cause over a median of 3.2 years. The trial findings were sensitive to the definition of myocardial infarction that was used. (Funded by the National Heart, Lung, and Blood Institute and others; ISCHEMIA ClinicalTrials.gov number, NCT01471522.).