Sarcopenia predicts adverse outcomes in an elderly population with coronary artery disease: a systematic review and meta-analysis

BACKGROUND: The development of sarcopenia is attributed to normal aging and factors like type 2 diabetes, obesity, inactivity, reduced testosterone levels, and malnutrition, which are factors of poor prognosis in patients with coronary artery disease (CAD). This study aimed to perform a meta-analysis to assess whether preoperative sarcopenia can be used to predict the outcomes after cardiac surgery in elderly patients with CAD. METHODS: PubMed, Embase, the Cochrane library, and Web of Science were searched for available papers published up to December 2020. The primary outcome was major adverse cardiovascular outcomes (MACE). The secondary outcomes were mortality and heart failure (HF)-related hospitalization. The random-effects model was used. Hazard ratios (HRs) with 95% confidence intervals (95%CIs) were estimated. RESULTS: Ten studies were included, with 3707 patients followed for 6 months to 4.5 ± 2.3 years. The sarcopenia population had a higher rate of MACE compared to the non-sarcopenia population (HR = 2.27, 95%CI: 1.58–3.27, P < 0.001; I(2) = 60.0%, P(heterogeneity) = 0.02). The association between sarcopenia and MACE was significant when using the psoas muscle area index (PMI) to define sarcopenia (HR = 2.86, 95%CI: 1.84–4.46, P < 0.001; I(2) = 0%, P(heterogeneity) = 0.604). Sarcopenia was not associated with higher late mortality (HR = 2.15, 95%CI: 0.89–5.22, P = 0.090; I(2) = 91.0%, P(heterogeneity) < 0.001), all-cause mortality (HR = 1.35, 95%CI: 0.14–12.84, P = 0.792; I(2) = 90.5%, P(heterogeneity) = 0.001), and death, HF-related hospitalization (HR = 1.37, 95%CI: 0.59–3.16, P = 0.459; I(2) = 62.0%, P(heterogeneity) = 0.105). The sensitivity analysis revealed no outlying study in the analysis of the association between sarcopenia and MACE after coronary intervention. CONCLUSION: Sarcopenia is associated with poor MACE outcomes in patients with CAD. The results could help determine subpopulations of patients needing special monitoring after CAD surgery. The present study included several kinds of participants; although non-heterogeneity was found, interpretation should be cautious. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-021-02438-w.