Abstract 10721: Impact of the Extent of Coronary and Myocardial Disease on the Treatment Effect of Surgical Revascularization in Patients With Ischemic Left Ventricular Dysfunction
Patients with ischemic cardiomyopathy often struggle with the decision to undergo coronary artery bypass graft surgery (CABG) because of their relatively higher operative risk. To identify those patients whose early risk is surpassed by subsequent survival benefit, we examined the impact of anatomic variables associated with poor prognosis on the treatment effect of CABG. All 1,212 patients enrolled in the NIH-sponsored STICH surgical revascularization hypothesis trial were included. Patients had coronary artery disease (CAD) amenable to CABG and ejection fraction (EF) ≤35%, and were randomized to receive CABG plus optimal medical therapy or optimal medical therapy alone (MED). This study focused on the following prognostic factors: 1) presence of 3-vessel CAD (≥50% stenosis); 2) EF below the median; and 3) end-systolic volume index (ESVI) above the median. Patients were categorized as having 0-1 or 2-3 of these factors. The primary endpoint was death from any cause on an intention-to-treat analysis. Of the 1,212 STICH patients, 733 had 3-vessel CAD. Median EF was 26.7% and median ESVI was 78.6 ml/m2. Patients with 2-3 prognostic factors (n= 636) had a significant reduction in the mortality rate with CABG, as compared to MED (5-year mortality 39% vs. 51%, respectively; HR=0.71, 95% CI=0.56-0.90; p=0.005); CABG had no such effect among patients with 0-1 factors (HR=1.09, 95% CI=0.81-1.45; p=0.558). There was a significant interaction between the number of prognostic factors and the treatment effect of CABG on mortality (p=0.022). Although 30-day risk with CABG was higher than with MED regardless of the number of prognostic factors, a beneficial effect of CABG began to emerge relatively early during follow-up in patients with 2-3 factors, resulting in a marked benefit of CABG over MED at ≥2 years in patients with 2-3 prognostic factors (HR=0.53, 95% CI=0.37-0.76; p<0.001), but not in patients with 0-1 factors (HR=0.89, 95% CI=0.60-1.32, p=0.553). In conclusion, patients with more advanced forms of ischemic cardiomyopathy are those that receive greater benefit from CABG. These findings support the indication for surgical revascularization in patients with more extensive CAD and greater degree of myocardial dysfunction and remodeling.
- © 2013 by American Heart Association, Inc.