# Evaluation of Risk Score for Isolated Surgical Aortic Valve Replacement and Transcatheter Aortic Valve Replacement—Results from the German National Quality Database

## TL;DR

This study compares risk scores for predicting mortality in two aortic valve treatments, finding that newer scores are more accurate than the commonly used Euroscore II.

## Contribution

The study evaluates the accuracy of AKL-Cath and AKL-Chir scores over Euroscore II for predicting mortality in TAVI and SAVR patients.

## Key findings

- The number of SAVR procedures decreased by 37.6% from 2015 to 2020, while TAVI procedures increased by 37.3%.
- In-hospital mortality for TAVI dropped from 4% to 2.5%, while SAVR mortality remained stable at 3%.
- AKL-Cath and AKL-Chir scores better estimate mortality risk than Euroscore II for TAVI and SAVR patients.

## Abstract

For the treatment of aortic valve stenoses, both surgical aortic valve replacement (SAVR) and transcatheter aortic valve implantation (TAVI) are available. We compared the frequently used Euroscore with the AKL-Cath- and the AKL-Chir Score, describing the mortality risk of the 2 different treatment methods.

Based on a retrospective cohort study using mandatory quality assurance data, we analysed the frequency and the outcomes (primary end-point: in-hospital mortality) of all patients treated in Germany between 2015 and 2020. The observed results were compared to the predicted risk using the Euroscore, the AKL-Cath Score, and the AKL-Chir Score.

Our data show a reduction in the number of isolated SAVR procedures from 9790 in 2015 to 6106 in 2020, corresponding to a 37.6% decrease. Over the same period, the number of TAVI procedures increased from 15 653 to 21 501, an increase of 37.3%. Regarding in-hospital mortality following TAVI, there was a decline from 4% (2015) to 2.5% (2020), while in-hospital mortality following SAVR remained nearly constant at 3%. Over the study period, there is an overestimation of TAVI risk while simultaneously underestimating SAVR risk by EuroSCORE II. In contrast, the mortality risk of patients is well estimated using the AKL-Kath Score in the TAVI group and the AKL-Chir Score in the SAVR group. The AKL-Chir Score in TAVI patients overestimates their mortality, while the AKL-Kath Score underestimates the mortality of SAVR patients.

AKL-Chir score and AKL-Cath score estimate the mortality risk of SAVR and TAVI patients more precisely than the Euroscore II.

The invasive treatment of aortic valve diseases comprises 2 different methods: isolated surgical aortic valve replacement (SAVR) under general anaesthesia with the use of cardiopulmonary bypass (CPB) or transcatheter aortic valve implantation (TAVI), usually under conscious sedation and without CPB on the beating heart.