From the Oxford Heart Centre, John Radcliffe Hospital, Oxford, United Kingdom (G.Y., S.M.R., D.P.T.); Department of Thoracic and Cardiovascular Surgery, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, Korea (G.Y.); Nuffield Department of Clinical Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom (B.S.); and Centre for Statistics in Medicine, University of Oxford, Oxford, United Kingdom (D.G.A.).
Circulation. 2014 Aug 12;130(7):539-45. doi: 10.1161/CIRCULATIONAHA.113.004255. Epub 2014 Jun 10.
Although the potential survival benefit of bilateral internal mammary artery (BIMA) grafting in comparison with single internal mammary artery (SIMA) grafting has been emphasized by many investigators, the use of BIMA is still low in clinical practice in the absence of randomized trials and long-term results. In the current study, we aimed to assess if there is a long-term survival benefit of BIMA up to 10 years after coronary bypass surgery.
We selected published articles comparing survival between SIMA and BIMA patients with follow-up duration of more than a mean of 9 years. We evaluated the log hazard ratio with 95% confidence interval for included studies by using a random-effects meta-analysis. Nine eligible observational studies provided 15 583 patients (8270 SIMA and 7313 BIMA) for meta-analysis. Five studies used propensity score methods for statistical adjustment, 2 with a propensity score-based patient-matching method and 3 with quintile-based stratification. A significant reduction in mortality by using BIMA was observed (hazard ratio, 0.79; 95% confidence interval, 0.75-0.84); no study showed any significantly harmful effect of BIMA on survival. Subgroups of studies using different statistical approaches-unmatched, quintile-based propensity score analysis, and propensity score-based exact patient matching-all showed the survival benefit of BIMA grafting.
BIMA grafting appears to have better survival with up to 10 years follow-up in comparison with SIMA grafting. Long-term survival benefit of BIMA seems to continue in the second decade after surgery. An ongoing randomized trial comparing SIMA and BIMA groups will add evidence on this issue.
尽管许多研究人员强调了双侧内乳动脉（BIMA）与单根内乳动脉（SIMA）搭桥相比的潜在生存获益，但在没有随机试验和长期结果的情况下，BIMA 在临床实践中的应用仍然较低。在本研究中，我们旨在评估在冠状动脉旁路手术后 10 年内 BIMA 是否具有长期生存获益。
我们选择了比较 SIMA 和 BIMA 患者生存情况的已发表文章，随访时间超过平均 9 年。我们通过使用随机效应荟萃分析，评估了纳入研究的对数风险比及其 95%置信区间。9 项符合条件的观察性研究提供了 15583 例患者（8270 例 SIMA 和 7313 例 BIMA）进行荟萃分析。其中 5 项研究使用了倾向评分方法进行统计学调整，其中 2 项采用了倾向评分匹配患者的方法，3 项采用了五分位分层。使用 BIMA 可显著降低死亡率（风险比，0.79；95%置信区间，0.75-0.84）；没有研究显示 BIMA 对生存有任何显著的有害影响。使用不同统计方法的研究亚组——未匹配、五分位倾向评分分析和倾向评分匹配患者——均显示了 BIMA 搭桥的生存获益。
与 SIMA 搭桥相比，BIMA 搭桥在长达 10 年的随访中显示出更好的生存获益。BIMA 搭桥的长期生存获益似乎在手术后的第二个十年中仍在继续。一项正在进行的比较 SIMA 和 BIMA 组的随机试验将为这一问题提供更多证据。
