Defining optimal muscle surface area thresholds for sarcopenia-related mortality after cardiovascular interventions

Abstract

Background and aims: Psoas muscle surface area (PMA) can estimate sarcopenia related long-term mortality risk. This study explored whether this association is linear or non-linear and if a meaningful threshold defines patients at high risk. Methods: This retrospective individual participant-level meta-analysis included four different cohorts of 3893 patients undergoing cardiovascular interventions: 1302 abdominal aortic aneurysm repairs (AAA), 1099 transcatheter aortic valve insertions (TAVI), 593 surgeries for thoracic aortic and aortic valve pathology (TA) and 899 procedures for peripheral artery disease (PAD). The association between PMA and mortality was visualized using pooled spline curves. Cox models were fitted separately within each cohort with three levels of adjustment, and hazard ratios were combined using inverse-variance meta-analysis. Results were replicated in a retrospective dataset of 561 patients undergoing carotid endarterectomy or thrombectomy for ischemic stroke, where sarcopenia status was estimated using masseter muscle surface area. Results: Age and sex were the most important features associating with PMA (p < 0.001), but significant variation between the cohorts was also observed (p < 0.001). The association between PMA and long-term mortality was inverse and linear (p < 0.001). Patients with poor muscle status (Z-values –1.5 or less for PMA) had significantly higher adjusted risk of death (hazard ratio (HR) of 1.6 with 95% confidence interval (CI) 1.3–2.0, p < 0.001) when compared to all other patients. Similar results were observed in the replication cohort (HR 1.7, 95% CI 1.0–2.82, p = 0.04). Conclusions: Long-term mortality after a cardiovascular intervention increases linearly as the PMA value decreases. Patients with poor muscle status (Z-values below –1.5) seem to have consistently elevated mortality risk independent of other risk factors.