Off-pump coronary artery bypass in patients with left ventricular dysfunction: a meta-analysis

Abstract

Background: In symptomatic multivessel disease with left ventricular dysfunction, coronary artery bypass surgery (CAB) is the conventional approach. This study assesses outcomes in patients with left ventricular dysfunction undergoing coronary artery bypass with (on-pump; ONCAB) and without cardiopulmonary bypass (off-pump; OPCAB).

Methods: A systematic literature search was performed and data were extracted for the following outcomes of interest: 30-day, midterm, and late-term mortality, myocardial infarction, and completeness of revascularization. Random effects meta-analysis was used to aggregate the data. Sensitivity, heterogeneity, and publication bias were assessed.

Results: Analysis of 23 nonrandomized studies revealed 7,759 patients, of whom 2,822 received OPCAB and 4,937 underwent ONCAB. Early mortality was significantly lower in the OPCAB group (odds ratio 0.64, 95% confidence interval 0.51 to 0.81) with no significant heterogeneity between the studies. This finding was supported by subgroup analysis that included assessment of studies only including patients with poor left ventricular function. Based on 13 studies, there was no difference in mortality at the midterm, and based on 4 studies there was no significant difference when comparing late-term mortality. Analysis of four studies revealed the OPCAB group was associated with significantly less complete revascularization.

Conclusions: Off-pump CAB may be associated with lower incidence of early mortality in patients with impaired left ventricular function, although the method of handling the conversion-related mortality in each study is uncertain and may challenge these results. Incomplete revascularization provided by the OPCAB group occurred more often, although its impact was not reflected in the clinical outcomes but may explain why the early advantage in mortality was not continued to the late term.