Evaluating TAVI quality indicators: critical insights from the SWEDEHEART experience and future directions

Dear Editor We read with great interest the recent publication entitled ‘Association between quality of care indicators and clinical outcomes in patients undergoing transcatheter aortic valve implantation: insights from SWEDEHEART’ by Nilsson K et al.1 This study conducts validation of the 2023 ESC Quality Indicators (QIs) for the transcatheter aortic valve implantation (TAVI) Swedish registry study. As per the findings, most indicators can be feasibly extracted and would correlate with 1-year mortality. Still, the clinical applicability or external validity may be limited. First, registry-based retrospective data are prone to incomplete variable capture and reporting bias. Outcome misclassification may occur because clinical events are approximated through registry variables, and incomplete, inconsistently defined, or missing data can lead to incorrect classification of whether an outcome truly occurred. Causal relationships cannot be established through observational designs. Propensity score-based matching may offer better confounding adjustment than traditional methods.2 Second, the authors report high overall attainment of quality indicators with low inter-centre variability. This may imply measurement error and lack of sensitivity to detect real differences, rather than genuinely uniform care quality. In comparison to the Danish TAVI registry, which demonstrated high variability in longer-term prognosis, individuals less than 80 years of age had a higher associated risk of death compared to the general population, while those 80 years of age and older had a lower risk.3 This supports variety in TAVI outcomes across Europe.