Frailty is common among older patients with heart failure (HF). The efficacy of coronary artery bypass grafting (CABG) on the risk of mortality among frail patients with ischemic cardiomyopathy and HF is uncertain, and whether frailty burden modifies the treatment benefits of CABG among these patients is unknown. We performed a post hoc analysis of the STICHES trial, a randomized trial of CABG with medical therapy vs medical therapy alone among participants with ischemic cardiomyopathy with ejection fraction ≤ 35%. Baseline frailty was assessed through a Rockwood Frailty Index (FI), and based on FI cut-offs from prior HF studies, participants with FI ≥ 0.311 were classified as more frail, and those with FI < 0.311 were classified as less frail. A multivariable Cox proportional hazard model with multiplicative interaction terms was constructed to evaluate whether frailty status modified the treatment effect of CABG on mortality in the overall trial cohort and among those < 60 vs ≥ 60 years of age. Of 1187 participants (12.4% female, 2.6% Black, median FI = 0.33 [IQR 0.27–0.39]), 678 were characterized as more frail. Frailty burden did not modify the efficacy of CABG on the risk of all-cause death in the overall cohort (P_int CABG × frailty = 0.2). In age stratified analysis, Baseline frailty status did not modify the treatment effect of CABG on the risk of all-cause mortality among younger (< 60 years, P_int CABG × frailty = 0.2) as well as older participants (≥60 years, P_int CABG × frailty = 0.6). In this post hoc analysis of the STICHES trial, baseline frailty status did not modify the efficacy of CABG in the overall cohort as well as among younger or older participants. Frailty alone should not be used as a criterion to determine the utilization of CABG among patients with ischemic cardiomyopathy.

虚弱在老年心力衰竭 （HF） 患者中很常见。冠状动脉旁路移植术 （CABG） 对缺血性心肌病和 HF 虚弱患者死亡风险的疗效尚不确定，虚弱负担是否会改变 CABG 在这些患者中的治疗益处尚不清楚。我们对 STICHES 试验进行了事后分析，这是一项在射血分数≤ 35% 的缺血性心肌病参与者中比较 CABG 联合药物治疗与单独药物治疗的随机试验。通过 Rockwood 衰弱指数 （FI） 评估基线衰弱，根据先前 HF 研究的 FI 临界值，FI ≥ 0.311 的参与者被归类为较虚弱，FI < 为 0.311 的参与者被归类为较不虚弱。构建了一个具有乘法交互项的多变量 Cox 比例风险模型，以评估虚弱状态是否改变了 CABG 对整个试验队列以及 < 60 岁对 60 岁≥死亡率的治疗效果。在 1187 名参与者（12.4% 为女性，2.6% 为黑人，中位 FI = 0.33 [IQR 0.27-0.39]）中，678 人被描述为更虚弱。衰弱负担并未改变 CABG 对整个队列中全因死亡风险的疗效 （P_int CABG × frailty = 0.2）。在年龄分层分析中，基线虚弱状态并未改变 CABG 治疗对年轻 （< 60 岁，P_int CABG × 虚弱 = 0.2） 以及老年 （≥60 岁，P_int CABG × 虚弱 = 0.6） 的全因死亡风险的影响。在 STICHES 试验的事后分析中，基线虚弱状态并未改变 CABG 在整个队列以及年轻或老年参与者中的疗效。 不应仅将虚弱作为确定缺血性心肌病患者 CABG 使用情况的标准。