Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada.
Ann Thorac Surg. 2011 Oct;92(4):1269-75; discussion 1275-6. doi: 10.1016/j.athoracsur.2011.05.083.
Although bilateral internal thoracic artery (BITA) grafting in coronary artery bypass grafting (CABG) is associated with low morbidity and good long-term results, controversy exists about the age after which BITA grafting is no longer beneficial. We sought to determine if such an age cutoff point exists.
The study cohort consisted of 5,601 consecutive patients from a cardiac surgery registry who underwent isolated CABG (1,038 [19%] BITA grafts, 4,029 [72%] single internal thoracic artery [SITA] grafts, 534 [10%] vein-only grafts) between 1995 and 2008. A Cox model was used to compare survival by use of bilateral, single, or no internal thoracic artery (ITA) grafts, adjusting for baseline clinical and demographic characteristics.
Mean follow-up was 7.1 years. Patients undergoing BITA grafting had the lowest 1-year mortality (2.4% versus 4.3% SITA grafting and 8.2% vein-only grafting; p < 0.0001). Relative to SITA grafting, a crude survival benefit of 54% existed for BITA grafting (hazard ratio [HR] 0.46; 95% confidence interval [CI], 0.37 to 0.57; p < 0.0001) with worse survival for vein-only grafts (HR, 1.16; 95% CI, 0.99 to 1.37; p = 0.07). After adjustment, the benefit of BITA grafting was no longer statistically significant (HR, 0.87; 95% CI, 0.69 to 1.08; p = 0.2). However age may be an effect modifier: a spline analysis plotting HR (BITA grafting versus SITA grafting) against age suggested a potential survival advantage associated with BITA grafting in patients younger than 69.9 years.
Bilateral internal thoracic artery grafting is a reasonable revascularization strategy in suitable patients up to age 70 years. As benefits of arterial grafting become more obvious over time, a longer period of follow-up will be needed to confirm the advantage of a BITA grafting strategy. In the meantime the BITA grafting advantage for patients older than 70 years is not clear.
虽然在冠状动脉旁路移植术中使用双侧内乳动脉（BITA）移植与较低的发病率和良好的长期结果相关，但对于 BITA 移植不再有益的年龄存在争议。我们试图确定是否存在这样的年龄界限。
研究队列由 1995 年至 2008 年间在心脏手术登记处接受单纯冠状动脉旁路移植术（1038 例[19%]BITA 移植，4029 例[72%]单内乳动脉[SITA]移植，534 例[10%]静脉移植）的 5601 例连续患者组成。使用 Cox 模型比较使用双侧、单侧或无内乳动脉（ITA）移植的生存情况，同时调整基线临床和人口统计学特征。
平均随访 7.1 年。接受 BITA 移植的患者 1 年死亡率最低（2.4%与 SITA 移植的 4.3%和静脉移植的 8.2%相比；p < 0.0001）。与 SITA 移植相比，BITA 移植的粗生存率有 54%的优势（风险比[HR]0.46；95%置信区间[CI]，0.37 至 0.57；p < 0.0001），静脉移植的生存率更差（HR，1.16；95%CI，0.99 至 1.37；p = 0.07）。调整后，BITA 移植的益处不再具有统计学意义（HR，0.87；95%CI，0.69 至 1.08；p = 0.2）。然而，年龄可能是一个效应修饰因子：绘制 HR（BITA 移植与 SITA 移植）与年龄的样条分析表明，在年龄小于 69.9 岁的患者中，与 BITA 移植相关的潜在生存优势。
在合适的患者中，双侧内乳动脉移植是一种合理的血运重建策略，年龄可达 70 岁。随着动脉移植益处随时间推移变得更加明显，需要更长的随访时间来确认 BITA 移植策略的优势。同时，对于 70 岁以上患者的 BITA 移植优势尚不清楚。
