Impact of Sarcopenia Index on Prognosis in Patients with Chronic Heart Failure

Background: The sarcopenia index (SI) was recommended as a surrogate marker of sarcopenia based on the serum creatinine-to-cystatin C ratio, given its accessibility and effectiveness. However, the impact of SI on chronic heart failure (HF) has not been addressed. Methods: A total of 1209 chronic HF patients from a retrospective cohort study were included. Cox regression and inverse probability of treatment weighting (IPTW) were used to analyze the impact of the SI on all-cause death and hospitalization. The C-index, net reclassification improvement (NRI), and discrimination improvement (IDI) were used to assess the predictive ability for all-cause death after the addition of SI. Results: By IPTW analysis, chronic HF patients with a high SI (SI> 62.5) demonstrated a decreasing trend of 28-day hospital death (HR=0.44, 95% CI = 0.06, 3.27, p=0.422), 3-month death (HR=0.45, 95% CI = 0.06, 3.42, p=0.441) and 6-month death (HR=0.44, 95% CI = 0.06, 3.27, p=0.422) compared with a low SI group (SI≤62.5). The subsequent meta-analysis revealed that a low SI was significantly associated with all-cause mortality (OR 0.42, 95% CI = 0.28, 0.62, I2 = 0, p < 0.0001) in patients with chronic HF. Finally, the SI significantly improved the predictive performance of 6-month allcause mortality in chronic HF patients via the integrated IDI (0.002, 95% CI= 0.00-0.120, p=0.033) but not the C-index (Z statistic=0.116) or NRI (0.114, 95% CI= -0.301--0.263). Discussion: Heart failure and sarcopenia share common pathogenetic pathways, including hormonal changes, malnutrition, inflammation and oxidative stress. Conclusion: A low SI may indicate a poorer prognosis in patients with chronic heart failure. These findings should be validated in larger, prospective studies.