ObjectivesWe explored the current evidence on the best second conduit in coronary surgery carrying out a double meta-analysis of propensity score matched or adjusted studies comparing bilateral internal thoracic artery (BITA) versus single internal thoracic artery plus radial artery. MethodsPubMed, Embase, and Google Scholar were searched for propensity score matched or adjusted studies comparing BITA versus single internal thoracic artery plus radial artery. The end point was long-term mortality. Two statistical approaches were used: the generic inverse variance method and the pooled meta-analysis of Kaplan–Meier-derived individual patient data. ResultsTwelve matched populations comparing 6450 patients with BITA versus 9428 patients with single internal thoracic artery plus radial artery were included in our meta-analysis. The generic inverse variance method showed a statistically significant survival benefit of the BITA group (hazard ratio, 0.84; 95% CI, 0.74-0.95; P = .04). The Kaplan-Meier estimates of survival at 1, 5, 10, and 15 years of the BITA group were 97.0%, 91.3%, 80.0%, and 68.0%, respectively. The Kaplan-Meier estimates of survival at 1, 5, 10, and 15 years of the single internal thoracic artery plus radial artery group were 97.3%, 91.5%, 79.9%, and 63.9%, respectively. The Kaplan–Meier-derived individual patient data meta-analysis applied to very long follow-up time data, showed that BITA provided a survival benefit after 10 years from surgery (hazard ratio, 0.77; 95% CI, 0.63-0.94; P = .01). No differences in terms of survival between the 2 groups were detected when the analysis was focused on the first 10 years of follow-up (hazard ratio, 0.99; 95% CI, 0.91-1.09; P = .93). ConclusionsThe present meta-analysis suggests that double internal thoracic artery may provide, compared with single internal thoracic artery plus radial artery, a statistically significant survival advantage after 10 years of follow-up, but not before. Video Abstract [Display omitted]