Caracciolo E A, Davis K B, Sopko G, Kaiser G C, Corley S D, Schaff H, Taylor H A, Chaitman B R
St Louis (Mo) University Health Sciences Center, USA.
Circulation. 1995 May 1;91(9):2325-34. doi: 10.1161/01.cir.91.9.2325.
Observational and randomized studies designed to compare surgical and medical therapies in patients with left main coronary artery disease (LMCD) have shown that coronary artery bypass graft (CABG) surgery prolongs life in most patients with LMCD. The present report of 1484 patients with LMCD in the Coronary Artery Surgery Study (CASS) Registry extends the originally published 5-year surgical and medical group survival analysis to more than 16 years of follow-up and permits analysis of LMCD patient subgroups.
The CASS Registry contains 1484 patients with > or = 50% left main coronary artery stenosis initially treated with either surgical or nonsurgical therapy. The 15-year cumulative survival estimates were 37% for the 1153 patients in the surgical group compared with 27% for the 331 patients in the medical group. Median survival in the surgical group was 13.3 years (12.8 to 13.8 years, 95% confidence limits) compared with only 6.6 years (5.4 to 7.9 years) in the medical group (difference, 6.7 years; P < .0001). Median survival was also significantly longer in the surgical group stratified by age, sex, anginal class, left ventricular (LV) function, coronary anatomy, and the extent of LMCD. However, CABG surgery did not significantly prolong median survival in patient subgroups with (1) left main coronary stenosis of 50% to 59%; (2) normal LV systolic function; (3) normal or mildly abnormal LV systolic function and a right coronary artery stenosis > or = 70%; and (4) a nonstenotic (< or = 70%) right coronary artery. The 15-year cumulative survival for patients with normal LV systolic function in the surgical and medical groups was 42% and 51%, respectively. Median survival was 14.7 years in the surgical group and > 15 years in the medical group (P = NS). In patients with normal LV systolic function and a right coronary artery stenosis > or = 70%, the 15-year cumulative survival rates were also similar in the surgical and medical groups (40% and 48%, respectively). Median survival was 14.3 years in the surgical group and 14.2 years in the medical group (P = NS). The 15-year cumulative survival estimates for all subgroups were affected by convergence of the surgical and medical survival group curves owing to a disproportionate increase in the late surgical group mortality. Overall, 25% of patients in the medical group ultimately underwent CABG surgery. If all medical group patients had survived long enough, about 47% would be estimated to have had surgery by 15 years.
This report, which extends follow-up of more than 16 years in CASS Registry patients with LMCD, shows that CABG surgery prolongs life in most clinical and angiographic subgroups. However, median survival was not prolonged by CABG surgery in patients with normal LV systolic function, even if a significant right coronary artery stenosis (> or = 70%) also was present. These results extend our understanding of the natural history of LMCD and permit a more accurate estimate of long-term surgical and medical group survival.
旨在比较左主干冠状动脉疾病（LMCD）患者手术治疗和药物治疗的观察性研究及随机研究表明，冠状动脉旁路移植术（CABG）能延长大多数LMCD患者的生命。冠状动脉手术研究（CASS）注册中心对1484例LMCD患者的本报告将最初发表的手术组和药物组5年生存分析扩展至超过16年的随访，并允许对LMCD患者亚组进行分析。
CASS注册中心包含1484例左主干冠状动脉狭窄≥50%且最初接受手术或非手术治疗的患者。手术组1153例患者的15年累积生存率估计为37%，而药物组331例患者为27%。手术组的中位生存期为13.3年（12.8至13.8年，95%置信区间），而药物组仅为6.6年（5.4至7.9年）（差异为6.7年；P<0.0001）。按年龄、性别、心绞痛分级、左心室（LV）功能、冠状动脉解剖结构和LMCD程度分层后，手术组的中位生存期也显著更长。然而，CABG手术并未显著延长以下患者亚组的中位生存期：（1）左主干冠状动脉狭窄50%至59%；（2）左心室收缩功能正常；（3）左心室收缩功能正常或轻度异常且右冠状动脉狭窄≥70%；（4）右冠状动脉无狭窄（≤70%）。手术组和药物组左心室收缩功能正常患者的15年累积生存率分别为42%和51%。手术组的中位生存期为14.7年，药物组>15年（P=无显著性差异）。在左心室收缩功能正常且右冠状动脉狭窄≥70%的患者中，手术组和药物组的15年累积生存率也相似（分别为40%和48%）。手术组的中位生存期为14.3年，药物组为14.2年（P=无显著性差异）。由于手术组晚期死亡率不成比例增加，手术组和药物组生存曲线的趋同影响了所有亚组的15年累积生存率估计。总体而言，药物组25%的患者最终接受了CABG手术。如果所有药物组患者存活时间足够长，估计到15年时约47%的患者会接受手术。结论：本报告对CASS注册中心的LMCD患者进行了超过16年的随访，表明CABG手术能延长大多数临床和血管造影亚组患者的生命。然而，即使存在显著的右冠状动脉狭窄（≥70%），CABG手术也未延长左心室收缩功能正常患者的中位生存期。这些结果扩展了我们对LMCD自然病史的理解，并允许更准确地估计手术组和药物组的长期生存率。
