Usefulness and validation of the survival posT TAVI score for survival after transcatheter aortic valve implantation for aortic stenosis

Surgical risk scores fail to accurately predict mortality after transcatheter aortic valve implantation (TAVI). The aim of this study was to develop and validate a dedicated risk score for accurate estimation of mortality risk in these patients. All consecutive patients who underwent TAVI at 6 international institutions were enrolled. Predictors for 1-year all-cause mortality were identified by means of Cox multivariate analysis and incorporated in a prediction score. Accuracy of the score was derived and externally validated for 30-day and 1-year mortality. The net classification improvement compared with the Society of Thoracic Surgeons (STS) score was appraised. A total of 1,064 patients constituted the derivation cohort and 180 patients constituted the external validation cohort. A total of 165 patients (15%) died at 1-year follow-up. Previous stroke (odds ratio [OR] 1.80, 1.4 to 3), inverse of renal clearance (OR 8, 6 to 14), and systolic pulmonary arterial pressure ≥50 mm Hg (OR 2.10, 1.5 to 3) were independently related to 1-year mortality. Area under the curve (AUC) of the survival post TAVI (STT) for 1-year mortality was 0.68 (0.62 to 0.71). At 30 days, 65 patients (7%) had died and the AUC for the STT at this time point was 0.66 (0.64 to 0.75). In the external validation cohorts, the AUC of the STT were 0.66 (0.56 to 0.7) for 30-day and 0.67 (0.62 to 0.71) for 1-year mortality. Net reclassification improvement for STT compared with STS was 31% (p <0.001) for 30-day mortality and 14% (p <0.001) for 1-year mortality. In conclusion, the STT score represents an easy and accurate tool to assess the risk of short-term and mid-term mortality in patients undergoing TAVI.