Abstract
BACKGROUND: Off-pump coronary artery bypass (OPCAB) has been shown to reduce the risk of neurologic complications as compared to coronary artery bypass grafting performed with cardiopulmonary bypass. Side-clamping of the aorta while constructing proximal anastomoses, however, still carries substantial risk of cerebral embolization. We aimed to perform a comprehensive meta-analysis of studies assessing 2 clampless techniques: aortic "no-touch" and proximal anastomosis devices (PAD) for OPCAB. METHODS AND RESULTS: PubMed, CINAHL, CENTRAL, and Google Scholar databases were screened for randomized controlled trials and observational studies comparing "no-touch" and/or PAD with side-clamp OPCAB and reporting short-term (≤30 days) outcomes: cerebrovascular accident and all-cause mortality. A total of 18 studies (3 randomized controlled trials) enrolling 25 163 patients were included. Aortic "no-touch" was associated with statistically lower risk of cerebrovascular accident as compared to side-clamp OPCAB: risk ratio 95% CI: 0.41 (0.27-0.61); P<0.01; I(2)=0%. Event rates were 0.36% and 1.28% for "no-touch" and side-clamp OPCAB, respectively. No difference was seen between PAD and side-clamp OPCAB: 0.71 (0.33-1.55); P=0.39; I(2)=39%. A trend towards increased 30-day all-cause mortality with PAD and no difference with "no-touch" were observed when compared to side-clamp OPCAB. In a subset analysis, "no-touch" consistently reduced the risk of cerebrovascular accident regardless of patients' baseline risk characteristics. A benefit with PAD was observed in low-risk patients. CONCLUSIONS: Aortic "no-touch" technique was associated with nearly 60% lower risk of postoperative cerebrovascular events as compared to conventional side-clamp OPCAB with effect consistent across patients at different risk.