Division of Cardiology, Yokohama City University Medical Center.
Department of Cardiology and Pneumology, University Medical Centre Göttingen.
J Atheroscler Thromb. 2020 Dec 1;27(12):1278-1287. doi: 10.5551/jat.52282. Epub 2020 Mar 5.
The importance of sarcopenia in cardiovascular diseases has been recently demonstrated. This study aims to examine whether skeletal muscle mass (SMM), an important component of sarcopenia, is associated with an increased risk of poor outcome in patients after ST-segment elevation myocardial infarction (STEMI).
We measured SMM in 387 patients with STEMI using dual-energy X-ray absorptiometry. Patients were divided into low- and high-appendicular skeletal mass index (ASMI: appendicular SMM divided by height squared (kg/m)) groups using the first quartile of ASMI (≤ 6.64 kg/m for men and ≤ 5.06 kg/m for women). All patients were followed up for the primary composite outcome of all-cause death, nonfatal myocardial infarction, nonfatal ischemic stroke, hospitalization for congestive heart failure, and unplanned revascularization.
Low-ASMI group was older and had a more complex coronary lesion, a lower left ventricular ejection fraction, and a higher prevalence of Killip classification ≥ 2 than high-ASMI group. During a median follow-up of 33 months, the event rate was significantly higher in low-ASMI group than in high-ASMI group (24.7% vs 13.4%, log-rank p=0.001). Even after adjustment for patients' background, low ASMI was independently associated with the high risk of primary composite events (adjusted hazard ratio 2.06, 95% confidence interval 1.01- 4.19, p=0.04). In the subgroup analyses of male patients (n=315), the optimal cutoff point of ASMI for predicting primary composite outcome was 6.75 kg/m, which was close to its first quartile value.
Low ASMI is independently associated with poor outcome in patients with STEMI.
骨骼肌减少症在心血管疾病中的重要性最近已经得到证实。本研究旨在探讨骨骼肌质量（SMM），作为骨骼肌减少症的一个重要组成部分，是否与 ST 段抬高型心肌梗死（STEMI）后患者不良预后风险增加相关。
我们使用双能 X 射线吸收法测量了 387 例 STEMI 患者的 SMM。患者根据四肢骨骼肌质量指数（ASMI：四肢骨骼肌质量除以身高平方（kg/m））的第一四分位数分为低和高 ASMI 组（男性≤6.64kg/m，女性≤5.06kg/m）。所有患者均随访主要复合终点事件，包括全因死亡、非致死性心肌梗死、非致死性缺血性卒、充血性心力衰竭住院和计划外血运重建。
低 ASMI 组年龄较大，冠状动脉病变较复杂，左心室射血分数较低，Killip 分级≥2的发生率较高。在中位 33 个月的随访期间，低 ASMI 组的事件发生率明显高于高 ASMI 组（24.7% vs 13.4%，对数秩检验 p=0.001）。即使在校正患者背景后，低 ASMI 与主要复合事件的高风险独立相关（调整后的危险比 2.06，95%置信区间 1.01-4.19，p=0.04）。在男性患者亚组分析（n=315）中，预测主要复合结局的 ASMI 的最佳截断点为 6.75kg/m，接近其第一四分位数值。
低 ASMI 与 STEMI 患者的不良预后独立相关。
