Risk model for mortality in Japanese patients requiring dialysis undergoing transcatheter aortic valve implantation: A report from a Japanese nationwide study

<h2>Abstract</h2><h3>Objectives</h3> Transcatheter aortic valve implantation (TAVI) is widely performed. However, the prognosis of patients requiring dialysis undergoing TAVI remains guarded; therefore, we aimed to establish a risk model to predict their prognosis. <h3>Methods</h3> A total of 888 patients requiring dialysis underwent TAVI for severe aortic stenosis between February 2021 and March 2022 at 54 facilities in Japan. Patients from 44 randomly selected facilities were included in the development cohort, and the rest were included in the validation cohort. Based on clinical perspective and prior research, 15 preoperative background factors, including the grade of clinical frailty scale (1-3, 4-6, or 7-9) and serum albumin level, were selected and a prognostic model was constructed using Cox proportional hazards regression. <h3>Results</h3> The median age of the patients was 80 years (interquartile range, 75-85 years). Three hundred nineteen men (35.9%) and 587 high-risk (Society of Thoracic Surgeons predicted risk of mortality ≥8%) patients (66.1%) were enrolled. The cumulative overall survival rates at 30 days and 1 year after TAVI were 95.9% and 78.3%, respectively. The exacerbated clinical frailty scale was strongly associated with 1-year mortality in the development cohort (hazard ratio, 2.06; 95% CI, 1.47-2.87). Uno's concordance index in the validation cohort was 0.686 (95% CI, 0.588-0.783). Observed survival rates were 91.7% (95% CI, 53.9%-98.8%) in the group with ≥90% predicted survival, 84.8% (95% CI, 70.7%-92.5%) in the group with 80% to <90% predicted survival, and 64.4% (95% CI, 51.9%-74.5%) in the group with <80% predicted survival. <h3>Conclusions</h3> The model developed in this study predicts 1-year survival probability, which is useful in considering indications for TAVI in patients requiring dialysis with a poor prognosis.