The Clinical Impact of Psoas Muscle Cross-Sectional Area on Medium-Term Mortality After Transcatheter Aortic Valve Implantation

Abstract

Psoas muscle cross-sectional area (CSA) is a proposed marker of frailty associated with mortality after transcatheter aortic valve implantation (TAVI). We assessed the impact of psoas CSA on medium-term mortality over 5 years in a large cohort, adjusted for pre-procedural variables. This single-centre registry-derived analysis assessed 1,731 consecutive TAVI patients between 2007 and 31 April 2015 with available abdominal computed tomography scans. Sex-stratified, height-adjusted psoas CSA was measured mid-body of the fourth lumbar vertebra. Kaplan-Meier survival distributions across psoas CSA quartiles were compared. Cox and logistic regression models were used to assess baseline variables associated with the primary outcome, which was mortality within 5 years. Median age was 81 years (interquartile range, 77 - 85); 52.5% were women. The primary endpoint occurred in 555 patients over a mean follow-up of 775 days. Lower psoas CSA quartile patients were older, had a lower body mass index, lower creatinine clearance, and lower rates of previous cardiac surgery, with higher rates of diabetes, coronary artery disease, pacemaker, anaemia, hypoalbuminaemia, and higher European System for Cardiac Operative Risk Evaluation (EuroSCORE). Unadjusted survival by psoas CSA quartile was significantly different in men (log rank p=0.041) but not women (p=0.099). In Bonferroni-adjusted multivariate analysis, psoas CSA quartiles were not significantly associated with mortality. Hypoalbuminaemia (hazard ratio [HR], 2.10; 95% confidence interval [CI], 1.53 - 2.87 [p<0.001]) and increasing age (HR, 1.03 per year; 95% CI, 1.01 - 1.05 [p=0.002]) were associated with increased risk; female sex (HR, 0.63; 95% CI 0.51 - 0.78 [p<0.001]), and hypercholesterolaemia (HR, 0.67; 95%, CI 0.54 0.83 [p<0.001]) with reduced risk. Psoas CSA was not significantly associated with mortality after adjusting for pre-procedural variables. Hypoalbuminaemia, sex, hypercholesterolaemia, and age were significantly associated with mortality after TAVI.