Impact of skeletal muscle mass on clinical outcomes in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement

Low skeletal muscle mass is one of the components of sarcopenia. However, the prognostic impact of skeletal muscle mass on clinical outcomes in patients after transcatheter aortic valve replacement (TAVR) remains unclear. Therefore, we assessed the impact of skeletal muscle mass on future cardiovascular events in patients undergoing TAVR. We enrolled 71 consecutive patients who underwent TAVR for symptomatic severe aortic stenosis. We applied bilateral psoas muscles as an indicator of skeletal muscle mass. Psoas muscle volumes were measured from the origin of psoas at the level of the lumbar vertebrae to its insertion in the lesser trochanter on three-dimensional computed tomography datasets. Psoas muscle mass index (PMI) was calculated as psoas muscle volume/height(2) (cm(3)/m(2)). According to the median value of PMIs (79.8 and 60.0 cm(3)/m(2) for men and women), the enrolled patients were divided into two groups. During the follow-up, 11 (31.4%) patients in low PMI group and 4 (11.1%) in high PMI group experienced major adverse cardiovascular events (MACE) defined as a composite of death from any cause, myocardial infarction, heart failure hospitalization, and stroke. The proportion of MACE-free survival was significantly lower in low PMI group (log-rank P = 0.033), mainly due to the difference of hospital readmission for congestive heart failure. On multivariate Cox proportional hazard analysis, PMI remained an independent negative predictor of MACE [hazard ratio 0.95 (95% confidence interval 0.92-0.98, P = 0.002)]. In conclusion, low skeletal muscle mass independently predicted MACE in patients undergoing TAVR.