Christakis G T, Weisel R D, Fremes S E, Ivanov J, David T E, Goldman B S, Salerno T A
Division of Cardiovascular Surgery, University of Toronto, Ontario, Canada.
J Thorac Cardiovasc Surg. 1992 Jun;103(6):1083-91; discussion 1091-2.
Although patients with severe ventricular dysfunction have improved long-term survival times after coronary bypass procedures, operative morbidity and mortality rates remain high. This study was designed to identify the contemporary risk factors for isolated coronary artery bypass grafting in this high-risk subgroup. Between January 1982 and December 1990, a total of 12,471 patients underwent isolated coronary artery bypass grafting. The 9445 patients with preoperative ejection fractions greater than 40% had a lower operative mortality rate (2.3%) than that of the 2539 patients with ejection fractions between 20% and 40% (4.8%) and that of the 487 patients with ejection fractions less than 20% (9.8%; p less than 0.001). However, patients with ejection fractions of less than 20% were demographically distinct from those with higher ejection fractions. This group was older, with fewer women, a higher frequency of left main stenosis, and more frequent requirement of urgent operation for unstable angina. The risk factors for operative death also varied with preoperative ejection fraction. The traditionally accepted risk factors--urgency of operation, left main coronary artery stenosis, reoperation, sex, and age--were predictive of risk of operative death for patients with ejection fractions greater than 40%. The risk of operative death for patients with ejection fractions between 20% and 40% was predicted by urgency of operation, reoperation, sex, myocardial protection, and age. The only predictor of risk of operative death for patients with ejection fractions less than 20% was urgency of operation. Patients undergoing isolated coronary artery bypass grafting who have severe ventricular dysfunction are therefore a highly selected, high-risk subgroup of patients who risk depends on the urgency of operation. Strategies to improve the results in these patients should be focused on patient selection, improvement of myocardial protection, and more aggressive preoperative treatment of myocardial ischemia.
尽管严重心室功能不全的患者在冠状动脉搭桥手术后长期生存时间有所改善，但手术的发病率和死亡率仍然很高。本研究旨在确定这一高危亚组中单纯冠状动脉搭桥术的当代危险因素。1982年1月至1990年12月期间，共有12471例患者接受了单纯冠状动脉搭桥术。术前射血分数大于40%的9445例患者手术死亡率（2.3%）低于射血分数在20%至40%之间的2539例患者（4.8%）以及射血分数低于20%的487例患者（9.8%；p<0.001）。然而，射血分数低于20%的患者在人口统计学特征上与射血分数较高的患者不同。该组患者年龄较大，女性较少，左主干狭窄频率较高，因不稳定型心绞痛而紧急手术的需求更频繁。手术死亡的危险因素也因术前射血分数而异。传统上公认的危险因素——手术紧迫性、左主干冠状动脉狭窄、再次手术、性别和年龄——可预测射血分数大于40%的患者的手术死亡风险。射血分数在20%至40%之间的患者的手术死亡风险可通过手术紧迫性、再次手术、性别、心肌保护和年龄来预测。射血分数低于20%的患者手术死亡风险的唯一预测因素是手术紧迫性。因此，接受单纯冠状动脉搭桥术且有严重心室功能不全的患者是经过高度筛选的高危亚组患者，其风险取决于手术的紧迫性。改善这些患者治疗效果的策略应集中在患者选择、改善心肌保护以及更积极地术前治疗心肌缺血方面
