Early and Midterm Outcome after Off-Pump Coronary Artery Bypass Grafting in Patients with Left Ventricular Dysfunction
Background: The purpose of this study was to define the early outcome and the potential for midterm survival in patients with left ventricular dysfunction (LVD) who undergo off-pump coronary artery bypass (OPCAB) and to compare these results with those of conventional coronary artery bypass grafting (CABG).
Methods: Medical records of patients with LVD (n = 732) between January 1998 and March 2002 were retrospectively reviewed. There were 523 patients with moderate LVD (ejection fraction, 30%-50%; 463 CABG versus 60 OPCAB) and 209 patients with severe LVD (ejection fraction, < 30%; 136 CABG versus 73 OPCAB). Midterm survival data (mean follow-up, 2.3 years) were obtained from the National Death Index. Groups were compared by multivariate Cox proportional hazard models, and Kaplan-Meier curves were plotted.
Results: CABG patients had lower European System for Cardiac Operative Risk Evaluation values (5.3 versus 7.2 and 8.0 versus 9.6 in moderate and severe LVD subgroups, respectively; P < .001). There were no differences (OPCAB versus CABG) in 30-day mortality (3.3% versus 1.9%, moderate LVD group, P = .366; 6.8% versus 4.4%, severe LVD group, P = .521), length of stay (9.3 versus 8.6 days, moderate LVD group, P = .683; 11.9 versus 11.8 days, severe LVD group, P = .423), and postoperative complications (13.3% versus 11.0%, moderate LVD group, P = 0.663; 16.4% versus 20.6%, severe LVD group, P = .581). Successful coronary bypass in patients with severe LVD was associated with 68.2% and 66.2% actuarial 48-month survival rates for the CABG and OPCAB patients, respectively (P = .336), and these rates rose to 86.0% and 82.9% in patients with moderate LVD (P = .121). When CABG patients with moderate LVD were considered the reference group, the adjusted hazard ratio of OPCAB patients with moderate LVD for midterm mortality was 1.32 (95% confidence interval, 0.61-2.87; P = .481). CABG and OPCAB patients with severe LVD had the same adjusted hazard ratio of 1.86, and this figure was statistically significant compared with the value for the reference group (P = .011 and P = .039, respectively).
Conclusions: Patients with LVD can derive midterm benefit from coronary bypass. OPCAB in higher-risk patients had early and midterm outcomes similar to those of CABG.
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