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 followup 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. / Clinical Trial Registration: URL: https://clinicaltrials.gov Unique Identifier: NCT0147152

Myocardial viability and survival in ischemic left ventricular dysfunction

BACKGROUND: The assessment of myocardial viability has been used to identify patients with coronary artery disease and left ventricular dysfunction in whom coronary-artery bypass grafting (CABG) will provide a survival benefit. However, the efficacy of this approach is uncertain. METHODS: In a substudy of patients with coronary artery disease and left ventricular dysfunction who were enrolled in a randomized trial of medical therapy with or without CABG, we used single-photon-emission computed tomography (SPECT), dobutamine echocardiography, or both to assess myocardial viability on the basis of prespecified thresholds. RESULTS: Among the 1212 patients enrolled in the randomized trial, 601 underwent assessment of myocardial viability. Of these patients, we randomly assigned 298 to receive medical therapy plus CABG and 303 to receive medical therapy alone. A total of 178 of 487 patients with viable myocardium (37%) and 58 of 114 patients without viable myocardium (51%) died (hazard ratio for death among patients with viable myocardium, 0.64; 95% confidence interval [CI], 0.48 to 0.86; P=0.003). However, after adjustment for other baseline variables, this association with mortality was not significant (P=0.21). There was no significant interaction between viability status and treatment assignment with respect to mortality (P=0.53). CONCLUSIONS: The presence of viable myocardium was associated with a greater likelihood of survival in patients with coronary artery disease and left ventricular dysfunction, but this relationship was not significant after adjustment for other baseline variables. The assessment of myocardial viability did not identify patients with a differential survival benefit from CABG, as compared with medical therapy alone. (Funded by the National Heart, Lung, and Blood Institute; STICH ClinicalTrials.gov number, NCT00023595.)