Effects of statin therapy on clinical outcomes after acute myocardial infarction in patients with advanced renal dysfunction: A propensity score-matched analysis

Objective
Lipid lowering therapy is widely used for the prevention of cardiovascular complications after acute myocardial infarction (AMI). However, some studies show that this benefit is uncertain in patients with renal dysfunction, and the role of statins is based on the severity of renal dysfunction. In this study, we investigated the impact of statin therapy on major adverse cardiac events (MACEs) and all-cause mortality in patients with advanced renal dysfunction undergoing percutaneous coronary intervention (PCI) after AMI.
Methods
This study was based on the Korea Acute Myocardial Infarction Registry database. We included 861 patients with advanced renal dysfunction from among 33,205 patients who underwent PCI after AMI between November 2005 and July 2012. Patients were divided into two groups: a statin group (n = 537) and a no-statin group (n = 324). We investigated the 12-month MACEs (cardiac death, myocardial infarction, repeated PCI or coronary artery bypass grafting) and all-cause mortality of each group. Subsequently, a propensity score-matched analysis was performed.
Results
In the total population studied, no significant differences were observed between the two groups with respect to the rate of recurrent MI, repeated PCI, coronary artery bypass grafting (CABG), or all-cause mortality. However, the cardiac death rate was significantly lower in the statin group (p = 0.009). Propensity score-matched analysis yielded 274 pairs demonstrating, results similar to those obtained from the total population. However, there was no significant difference in the cardiac death rate in the propensity score-matched population (p = 0.103). Cox-regression analysis revealed only left ventricular ejection fraction to be an independent predictor of 12-month MACEs (Hazard ratio [HR] of 0.979, 95% confidence interval [CI], 0962–0.996, p = 0.018).
Conclusions
Statin therapy was not significantly associated with a reduction in the 12-month MACEs or all-cause mortality in patients with advanced renal dysfunction undergoing PCI after AMI.

研究目的：调脂治疗（Lipid lowering therapy）广泛用于急性心肌梗死（acute myocardial infarction, AMI）后心血管并发症的预防。然而部分研究表明，该治疗在肾功能不全患者中的获益尚不明确，且他汀类药物（statins）的作用需依据肾功能不全的严重程度而定。本研究旨在探讨他汀类药物治疗对急性心肌梗死后接受经皮冠状动脉介入治疗（percutaneous coronary intervention, PCI）的晚期肾功能不全患者主要不良心血管事件（major adverse cardiac events, MACEs）及全因死亡率的影响。

研究方法：本研究基于韩国急性心肌梗死注册研究（Korea Acute Myocardial Infarction Registry）数据库。研究纳入2005年11月至2012年7月间33205例急性心肌梗死后接受经皮冠状动脉介入治疗的患者中，861例晚期肾功能不全患者。将患者分为两组：他汀组（n = 537）与非他汀组（n = 324）。本研究观察两组患者12个月内的主要不良心血管事件（包括心源性死亡、心肌梗死、再次行经皮冠状动脉介入治疗或冠状动脉旁路移植术（coronary artery bypass grafting, CABG））及全因死亡率。随后进行倾向性评分匹配分析。

研究结果：在全部研究人群中，两组患者的复发性心肌梗死、再次行经皮冠状动脉介入治疗、冠状动脉旁路移植术发生率及全因死亡率均无显著差异。但他汀组的心源性死亡率显著更低（p = 0.009）。倾向性评分匹配分析得到274对匹配样本，其分析结果与总人群相似，但该匹配人群中的心源性死亡率无显著差异（p = 0.103）。Cox回归分析显示，仅左心室射血分数为12个月主要不良心血管事件的独立预测因子（风险比（Hazard ratio, HR）= 0.979，95%置信区间（confidence interval, CI）：0.962–0.996，p = 0.018）。

研究结论：对于急性心肌梗死后接受经皮冠状动脉介入治疗的晚期肾功能不全患者，他汀类药物治疗与12个月主要不良心血管事件发生率降低及全因死亡率降低均无显著相关性。