Background and Aims A routine invasive strategy is recommended in the management of higher risk patients with non-ST-elevation acute coronary syndromes (NSTE-ACSs). However, patients with previous coronary artery bypass graft (CABG) surgery were excluded from key trials that informed these guidelines. Thus, the benefit of a routine invasive strategy is less certain in this specific subgroup. Methods A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted. A comprehensive search was performed of PubMed, EMBASE, Cochrane, and ClinicalTrials.gov. Eligible studies were RCTs of routine invasive vs. a conservative or selective invasive strategy in patients presenting with NSTE-ACS that included patients with previous CABG. Summary data were collected from the authors of each trial if not previously published. Outcomes assessed were all-cause mortality, cardiac mortality, myocardial infarction, and cardiac-related hospitalization. Using a random-effects model, risk ratios (RRs) with 95% confidence intervals (CIs) were calculated. Results Summary data were obtained from 11 RCTs, including previously unpublished subgroup outcomes of nine trials, comprising 897 patients with previous CABG (477 routine invasive, 420 conservative/selective invasive) followed up for a weighted mean of 2.0 (range 0.5–10) years. A routine invasive strategy did not reduce all-cause mortality (RR 1.12, 95% CI 0.97–1.29), cardiac mortality (RR 1.05, 95% CI 0.70–1.58), myocardial infarction (RR 0.90, 95% CI 0.65–1.23), or cardiac-related hospitalization (RR 1.05, 95% CI 0.78–1.40). Conclusions This is the first meta-analysis assessing the effect of a routine invasive strategy in patients with prior CABG who present with NSTE-ACS. The results confirm the under-representation of this patient group in RCTs of invasive management in NSTE-ACS and suggest that there is no benefit to a routine invasive strategy compared to a conservative approach with regard to major adverse cardiac events. These findings should be validated in an adequately powered RCT.

中文翻译：

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既往冠状动脉搭桥术引起的非 ST 段抬高急性冠脉综合征：侵入性治疗与保守性治疗的荟萃分析


背景和目的 建议在治疗非 ST 段抬高急性冠脉综合征 (NSTE-ACS) 的高危患者时采用常规侵入性策略。然而，既往接受过冠状动脉搭桥术（CABG）手术的患者被排除在为这些指南提供信息的关键试验之外。因此，在这个特定亚组中，常规侵入性策略的益处不太确定。方法 对随机对照试验（RCT）进行系统评价和荟萃分析。对 PubMed、EMBASE、Cochrane 和 ClinicalTrials.gov 进行了全面检索。符合条件的研究是针对 NSTE-ACS 患者（包括既往接受过 CABG 的患者）进行常规侵入性治疗与保守或选择性侵入性治疗策略的随机对照试验。如果之前没有发表的话，摘要数据是从每项试验的作者那里收集的。评估的结果包括全因死亡率、心脏死亡率、心肌梗死和心脏相关住院治疗。使用随机效应模型，计算具有 95% 置信区间 (CI) 的风险比 (RR)。结果总结数据来自 11 项随机对照试验，包括先前未发表的 9 项试验的亚组结果，其中包括 897 名既往接受过 CABG 的患者（477 名常规侵入性患者，420 名保守/选择性侵入性患者），随访加权平均时间为 2.0 年（范围 0.5-10）年。常规侵入性策略并未降低全因死亡率（RR 1.12，95% CI 0.97–1.29）、心脏死亡率（RR 1.05，95% CI 0.70–1.58）、心肌梗死（RR 0.90，95% CI 0.65–1.23） ，或与心脏相关的住院治疗（RR 1.05，95% CI 0.78–1.40）。结论 这是第一个评估常规侵入性策略对既往接受过 CABG 且出现 NSTE-ACS 的患者效果的荟萃分析。 结果证实该患者组在 NSTE-ACS 侵入性治疗的随机对照试验中代表性不足，并表明对于主要不良心脏事件，常规侵入性策略与保守方法相比没有任何益处。这些发现应该在充分有力的随机对照试验中得到验证。