Abstract 17751: Low Appendicular Skeletal Muscle Mass is Associated With High Coronary Plaque Complexity in Patients With ST-segment Elevation Myocardial Infarction

Abstract

Introduction: Loss of skeletal muscle mass is associated with diabetes, insulin resistance, inflammation, and generalized atherosclerosis. The angiographic complexity of coronary artery disease can predict outcomes in patients undergoing percutaneous coronary intervention. However, the relationship between skeletal muscle mass and ST-segment elevation myocardial infarction (STEMI) remains undetermined. Hypothesis: We assessed the hypothesis that low appendicular skeletal muscle mass index (ASMI) is associated with high coronary plaque complexity in patients with STEMI. Methods: We enrolled consecutive 112 patients with STEMI (age 64±12, male 87.5%) in this study. Appendicular skeletal muscle mass was estimated from dual-energy X-ray absorptiometry (DXA) scan before discharge and ASMI was defined as appendicular skeletal muscle mass divided by height squared (kg/m 2 ). ASMI was dichotomized according to the Asia Working Group for Sarcopenia criteria, which determined low (<7.0 kg/m 2 for men and <5.4 kg/m 2 for women by DXA) and normal ASMI. And we graded the coronary plaque complexity by using the Synergy between Percutaneous Coronary Intervention with Taxus and Coronary Surgery (SYNTAX) score at the initial coronary angiography. Result: ASMI correlated positively with body mass index (r=0.80, P<0.001), as well as negatively with age (r=-0.63, P<0.001), SYNTAX score (r=-0.28, P=0.003), Killip classification (r=-0.22, P=0.019), and B-type natriuretic peptide levels on admission (r=-0.27, P=0.014). The prevalence of low ASMI patients was 41% (n=46). Low ASMI patients had higher SYNTAX score (19.0±8.3 versus 13.7±7.7, P=0.001) compared with normal ASMI patients. Multivariate logistic regression analysis including age, gender and various classical risk factors demonstrated that ASMI significantly and independently correlated with moderate-severe coronary plaque complexity (SYNTAX score>22, n=22) in STEMI patients (odds ratio per 1: 0.55, 95%-confidence interval: 0.35-0.87, P=0.01). Conclusion: Low ASMI is significantly associated with high coronary plaque complexity in patients with STEMI, suggesting that skeletal muscle mass could play a crucial role in the pathogenesis of atherosclerosis in patients with STEMI.