TAVI risk scoring using established versus new scoring systems: role of the new STS/ACC model

Aims: The aim of this study was to validate the recently developed STS/ACC TAVR in-hospital mortality risk score for predicting in-hospital mortality after transcatheter aotic valve implantation (TAVI) and to compare its ability to predict 30-day mortality with that of four other established risk models (EuroSCORE I, EuroSCORE II, STS-PROM, and German AV Score). Methods and results: The study cohort included 946 consecutive patients who underwent TAVI between 2013 and 2015. Each of the five scores was fitted as a continuous linear variable into a logistic regression model estimating 30-day mortality. The STS/ACC TAVR score was additionally analysed for in-hospital mortality. C-statistics and likelihood ratio (LR) test p-values were estimated for each model to describe the model fit. The ability of the STS/ACC score to predict in-hospital mortality was similar to the reported STS/ACC TVT registry data (this study's C-statistic 0.65 vs. STS/ACC TVT registry 0.66). The STS-PROM score (C-statistic=0.68; LR p<0.0001) and the new STS/ACC TAVR score (C-statistic=0.68; LR p<0.0001) were superior to the other scores (EuroSCORE I [C-statistic=0.55; LR p=0.02], EuroSCORE II [C-statistic= 0.58; LR p=0.02], German AV Score [C-statistic=0.62; LR p<0.01]) for prediction of 30-day mortality. Conclusions: These data show the superiority of the STS-PROM and STS/ACC TAVR scores compared with other existing risk calculation models in predicting 30-day mortality after TAVI in a German all-comers population. The STS/ACC TAVR score, however, is easier to calculate (12 vs. 28 variables), and may thus gain wider acceptance and be accompanied by improved inter-observer reliability.