Are two really always better than one? Results, concerns and controversies in the use of bilateral internal thoracic arteries for coronary artery bypass grafting in the elderly: a systematic review and meta-analysis

Introduction: Bilateral internal thoracic artery grafting appears to be the preferred method to achieve durable long-term coronary artery revascularization. However, data reporting the benefit of this technique in the elderly is very conflicting.

Method: We performed a systematic review of available literature (till November 2014) using multiple databases to identify studies comparing clinical events in patients undergoing coronary artery bypass grafting using either a single or double internal thoracic artery in the elderly. While early mortality was the primary end-point of inclusion, other adverse events compared were sternal wound infection (deep and superficial), stroke and peri-operative myocardial infarction. Individual and pooled odd's ratios were calculated using the Mantel-Haenzel method (random effect model); sensitivity analysis was performed. Results are presented using 95% confidence intervals.

Result: Nine retrospective studies (4479 BITA, 7733 LITA patients) fulfilled search criteria. Deep sternal wound infection was significantly higher after BITA harvest [OR 1.86 (1.3-2.5); I(2) = 0%; p < 0.01]. Early mortality (BITA 3.6% vs SITA 3.1%; p = 0.86), stroke [OR 0.7(0.4-1.1); p = 0.1], and peri-operative myocardial infarction (BITA 4.3% vs SITA 2.3%; p = 0.1) were comparable in both cohorts. Long-term survival favored the BITA cohort in two propensity matched studies.

Conclusion: The incidence of deep sternal wound infection may be significantly higher after the harvest of both internal thoracic arteries in the elderly. While other post-operative adverse events are comparable, data regarding the long-term survival advantage in this cohort is conflicting. Hence, the use of both internal thoracic arteries in this age group needs to be invidualized.