Skeletal muscle index as a prognostic marker for sudden cardiac death in heart failure patients with reduced ejection fraction

Abstract

Abstract Background The association between sarcopenia and sudden cardiac death remains unclear. Therefore, this study aimed to explore the association between sarcopenia, sudden cardiac death, and all-cause mortality in heart failure (HF) patients with reduced ejection fraction based on the skeletal muscle index (SMI) predicted by a formula. Methods A total of 300 patients with heart failure who were admitted to our Hospital, National Center for Cardiovascular Diseases, between March 2013 and November 2015 and met the inclusion criteria were retrospectively analyzed. Baseline SMI was divided into two groups: lower than or equal to the median (n=151) and higher than the median (n=149). The primary endpoints were a composite outcome of sudden cardiac death (SCD) or an equivalent event (sustained ventricular events, or appropriate implantable cardioverter-defibrillator (ICD) therapy).The secondary end point was all-cause mortality. Results The average follow-up period was 24.40 ± 14.07 months. Atotal of 42 patients (42/300,14.0%) experienced sudden cardiac death or an equivalent event, and 97 patients (97/300, 32.2%) experienced all-cause mortality. Analysis of the Kaplan–Meier survival curves showed that patients with an SMI lower than or equal to the median had a higher risk of sudden cardiac death (P=0.0015) and all-cause mortality (P<0.0001). Multivariate Cox analysis showed that an SMI lower than the median was an independent risk factor for sudden cardiac death (hazard ratio (HR): 2.837, 95% confidence interval (CI): 1.009–7.980, P=0.048) and all-cause mortality (HR: 2.597, 95% CI: 1.384–4.871, P=0.003). Conclusions Decreased SMI significantly increased the risk of sudden cardiac death and all-cause mortality in patients with HF and reduced ejection fraction. In a HF population with reduced ejection fraction, attention should be paid to the effect of sarcopenia on prognosis, and active intervention is expected to improve the prognosis of patients.