JTCVS publishes a meta-analysis of BIMA versus LIMA

Takagi H, et al. – A 12–year–ago landmark meta–analysis of bilateral versus single internal thoracic artery (bilateral ITA [BITA] versus single ITA [SITA]) coronary artery bypass grafting for long–term survival included 7 observational studies (only 3 of which reported adjusted hazard ratios [HRs]) enrolling approximately 16,000 patients. Updating the previous meta–analysis to determine whether BITA grafting reduces long–term mortality over SITA grafting, the authors exclusively abstracted (then combined in a meta–analysis) adjusted (not unadjusted) HRs from observational studies. Based on an updated meta–analysis of exclusive adjusted HRs from 20 observational studies enrolling >70,000 patients, BITA grafting appears to significantly reduce long–term mortality. As the proportion of men increases, BITA grafting is more beneficial in reducing the mortality.

Methods

• MEDLINE and EMBASE were searched through September 2013.
• Eligible studies were observational studies of BITA versus SITA grafting and reporting adjusted HRs for long-term (≥4-year) mortality as an outcome.
• Meta-regression analyses were performed to determine whether the effects of BITA grafting were modulated by the pre-specified factors.

Results

• Twenty observational studies enrolling 70,897 patients were identified and included.
• A pooled analysis suggested a significant reduction in long-term mortality with BITA relative to SITA grafting (HR, 0.80; 95% confidence interval, 0.77 to 0.84).
• When data from 6 pedicled and 6 skeletonized ITA studies were separately pooled, BITA grafting was associates with a statistically significant 26% and 16% reduction in mortality relative to SITA grafting, respectively (P for subgroup differences = .04).
• A meta-regression coefficient was significantly negative for proportion of men (–0.00960; -0.01806 to -0.00114).