Wallis J B, Supino P G, Borer J S
Cardiology Division, Cornell University Medical College, New York Hospital-Cornell Medical Center, NY 10021.
Circulation. 1993 Nov;88(5 Pt 2):II99-109.
Recent data, albeit based on operations often performed more than 15 years ago, suggest that survival benefits of coronary artery bypass graft surgery (CABG) generally are lost within 10 years after operation. A reliable noninvasive method for periodic assessment of ischemia severity after operation might permit optimal timing of additional therapy to minimize loss of benefits.
To determine the impact of left ventricular ejection fraction (LVEF) during exercise on prognosis in patients who have undergone CABG, results of rest and exercise radionuclide cineangiography were correlated with mortality, major nonsurgical cardiac events, and cardiac event-free or surgery-free survival in 192 patients who underwent index radionuclide study > or = 1 month (average, 26 months) after CABG. Average follow-up after study was 8.7 years among event-free patients. Initial events during follow-up included 31 deaths, 19 nonfatal myocardial infarctions, and 33 late repeat CABG or angioplasties (PTCA). Stepwise Cox regression analysis identified change (delta) in LVEF with exercise as the strongest independent predictor of cardiac death, major nonsurgical cardiac events, and cardiac event-free or surgery-free survival (P < .0001, all outcomes). Change in heart rate with exercise, completeness of revascularization, and New York Heart Association functional class for angina provided additional independent information. With each 10% decrement in delta LVEF, the hazard of cardiac death increased more than twofold, and the hazard of major nonsurgical cardiac events considered alone or in combination with repeat CABG or PTCA increased > 1.5 times.
Thus, assessment of delta LVEF is prognostically useful after CABG. Assessment of this variable may help determine the need for repeat CABG. The utility of this approach now should be confirmed by longitudinal prognostic study.
近期数据表明，尽管这些数据基于通常在15年多以前实施的手术，但冠状动脉旁路移植术（CABG）的生存获益通常在术后10年内消失。一种可靠的用于术后定期评估缺血严重程度的非侵入性方法可能允许进行最佳时机的额外治疗，以尽量减少获益的丧失。
为了确定运动期间左心室射血分数（LVEF）对接受CABG患者预后的影响，对192例在CABG术后≥1个月（平均26个月）接受首次放射性核素检查的患者，将静息和运动放射性核素电影血管造影结果与死亡率、主要非手术性心脏事件以及无心脏事件或无再次手术生存情况进行关联分析。无事件患者的研究后平均随访时间为8.7年。随访期间的初始事件包括31例死亡、19例非致命性心肌梗死以及33例晚期再次CABG或血管成形术（PTCA）。逐步Cox回归分析确定运动时LVEF的变化（δ）是心脏死亡、主要非手术性心脏事件以及无心脏事件或无再次手术生存的最强独立预测因素（所有结局，P<0.0001）。运动时心率的变化、血运重建的完整性以及纽约心脏协会心绞痛功能分级提供了额外的独立信息。随着δLVEF每降低10%，心脏死亡风险增加超过两倍，单独或与再次CABG或PTCA合并考虑的主要非手术性心脏事件风险增加>1.5倍。
因此，CABG术后评估δLVEF对预后有帮助。对该变量的评估可能有助于确定再次CABG的必要性。现在应通过纵向预后研究来证实这种方法的实用性。
