Coronary-artery bypass surgery in patients with left ventricular dysfunction

Abstract

Background: The role of coronary-artery bypass grafting (CABG) in the treatment of patients with coronary artery disease and heart failure has not been clearly established.

Methods: Between July 2002 and May 2007, a total of 1212 patients with an ejection fraction of 35% or less and coronary artery disease amenable to CABG were randomly assigned to medical therapy alone (602 patients) or medical therapy plus CABG (610 patients). The primary outcome was the rate of death from any cause. Major secondary outcomes included the rates of death from cardiovascular causes and of death from any cause or hospitalization for cardiovascular causes.

Results: The primary outcome occurred in 244 patients (41%) in the medical-therapy group and 218 (36%) in the CABG group (hazard ratio with CABG, 0.86; 95% confidence interval [CI], 0.72 to 1.04; P=0.12). A total of 201 patients (33%) in the medical-therapy group and 168 (28%) in the CABG group died from an adjudicated cardiovascular cause (hazard ratio with CABG, 0.81; 95% CI, 0.66 to 1.00; P=0.05). Death from any cause or hospitalization for cardiovascular causes occurred in 411 patients (68%) in the medical-therapy group and 351 (58%) in the CABG group (hazard ratio with CABG, 0.74; 95% CI, 0.64 to 0.85; P<0.001). By the end of the follow-up period (median, 56 months), 100 patients in the medical-therapy group (17%) underwent CABG, and 555 patients in the CABG group (91%) underwent CABG.

Conclusions: In this randomized trial, there was no significant difference between medical therapy alone and medical therapy plus CABG with respect to the primary end point of death from any cause. Patients assigned to CABG, as compared with those assigned to medical therapy alone, had lower rates of death from cardiovascular causes and of death from any cause or hospitalization for cardiovascular causes. (Funded by the National Heart, Lung, and Blood Institute and Abbott Laboratories; STICH ClinicalTrials.gov number, NCT00023595.).

Figure 1. Kaplan-Meier Curves for the Probability of Death from Any Cause

CABG denotes coronary-artery bypass grafting.

Figure 2. Kaplan-Meier Curves for the Probability of Death from Cardiovascular Causes and of Death from Any Cause or Hospitalization for Cardiovascular Causes

CABG denotes coronary-artery bypass grafting.

Figure 3. Hazard Ratio for Death from Any Cause, According to Subgroup

Stratum A included patients eligible for either medical therapy alone or medical therapy plus coronary-artery bypass grafting (CABG), and stratum B included patients eligible for medical therapy alone, medical therapy plus CABG, or medical therapy plus CABG and surgical ventricular reconstruction. The Canadian Cardiovascular Society (CCS) angina classification ranges from class 0, which indicates no symptoms, to class IV, which indicates angina at any level of physical exertion. LM denotes left main coronary artery, LVEF left ventricular ejection fraction, NYHA New York Heart Association, and PLAD proximal left anterior descending artery.