Association of myocardial injury with adverse long-term survival among patients with sarcopenia.

Abstract

Background: Sarcopenia is an age-related progressive syndrome characterized by reductions in skeletal muscle mass, decreased muscle strength, and impaired physical performance. Although sarcopenia has been correlated with elevated CVD risk, the prognostic impact of myocardial injury, measured by high‑sensitivity cardiac troponin (hs‑cTn), on extended outcomes in individuals with sarcopenia remains unclear. This study sought to determine the extent to which myocardial injury is associated with all‑cause and CVD mortality among adults with sarcopenia.

Methods: We obtained data from NHANES 1999-2004. Sarcopenia was defined as an appendicular lean mass (ALM)-to-body mass index (BMI) ratio of < 0.789 for men and < 0.512 for women. Myocardial injury was defined as any hs‑cTn assay result above the sex‑specific 99th percentile across the Roche hs‑cTnT, Abbott hs‑cTnI, Siemens hs‑cTnI, and Ortho hs‑cTnI platforms. Weighted Cox models yielded hazard ratios (HRs) and 95%CI, and Fine‑Gray models accounted for competing non‑CVD deaths. Sensitivity analyses were run to exclude baseline CVD cases or deaths within two years of enrollment. Sex, race, income, smoking, drinking, BMI, and education were used as stratification variables in subgroup analyses.

Results: Among 1061 sarcopenic adults, 306 had myocardial injury. These individuals were older with higher burdens of hypertension, diabetes, and prior CVD. Over median 188‑month follow‑up, the myocardial injury group showed lower survival probability (P < 0.001). After full adjustment, myocardial injury was independently associated with all‑cause (HR=1.88; 95%CI:1.41, 2.49) and CVD mortality (HR=2.19; 95%CI:1.34, 3.59). Excluding baseline CVD raised the CVD‑death HR to 2.64(1.48, 4.71); excluding 2‑year deaths yielded all‑cause HR = 1.68 (1.12, 2.53) and CVD‑death HR = 2.49 (1.33, 4.67). Subgroup analyses showed consistent effects across most strata (all P for interaction > 0.05), except for education (P for interaction=0.031).

Conclusions: Myocardial injury was present in approximately 27% of sarcopenic adults and was independently associated with increased risks of all-cause and cardiovascular mortality. The associations remained robust across sensitivity analyses and were generally consistent across subgroups. These findings suggest that myocardial injury may provide prognostic information beyond conventional risk factors in adults with sarcopenia.