Prognostic value of estimating appendicular muscle mass in heart failure using creatinine/cystatin C

Abstract

Abstract Objectives As heart failure with concomitant sarcopenia has a poor prognosis, simple methods for evaluating the appendicular skeletal muscle mass index (ASMI) are required. Recently, a model incorporating anthropometric data and the sarcopenia index, that is, the ratio of serum creatinine to cystatin C (Cre/CysC), was developed to estimate the appendicular skeletal muscle mass. We hypothesized that this model would be superior to the previous model, which uses only anthropometric data to predict the prognosis. This study aimed to compare the prognostic value of low ASMI as defined by the biomarker and anthropometric models in patients with heart failure. Methods Among 847 patients, we estimated ASMI using an anthropometric model consisting of age, body weight, and height in 791 patients and a biomarker model that incorporates age, body weight, hemoglobin, and Cre/CysC in 562 patients. Patients were divided into low and non-low ASMI groups according to the ASMI estimated by each model, using the cut-off proposed by the Asian Working Group for Sarcopenia. The primary outcome was all-cause mortality. Results Overall, 53.4% and 39.1% of patients were diagnosed with low ASMI by anthropometric and biomarker models, respectively. The agreement of the diagnosis of low ASMI between the two models was poor, with a kappa coefficient of 0.56 (95% confidence interval: 0.49–0.63). Kaplan-Meier curves showed that a low ASMI was significantly associated with all-cause death in both models. However, this association was retained after adjustment for other covariates in the biomarker model (hazard ratio: 2.60, p=0.003), but not in the anthropometric model (hazard ratio: 0.70, p=0.257). Conclusions and implications Among patients hospitalized with heart failure, a low ASMI estimated using the biomarker model, but not the anthropometric model, was significantly associated with all-cause mortality. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Japan Agency for Medical Research and Development