Peripheral vessel tortuosity index and prognosis in patients undergoing transcatheter aortic valve implantation

The peripheral vessel tortuosity index (TI) was proposed to discriminate procedural success in patients undergoing transcatheter endovascular aortic replacement but not in those undergoing transcatheter aortic valve implantation (TAVI). We aimed to investigate the TI and its prognostic relevance in patients undergoing transfemoral (Tf) TAVI.

Retrospective, observational single-center study, including patients undergoing Tf-TAVI from April 2011 to January 2023 at the TUM University Hospital, German Heart Centre, and available computed tomography angiography (CTA). Peripheral vessel measurements were performed using dedicated software (3mensio, Pie Medical). TI was determined dividing true central lumen vessel length from centerline reconstruction and direct distance from the aorto-iliac bifurcation to the epigastric artery. TI was dichotomized based on severity according to EVAR guidelines, where a TI of 1.5 is considered discriminatory for nonsevere tortuosity [< 1.5 for low TI (LTI)] and > 1.5 for high TI (HTI)]. Valve Academic Research Consortium 3 definitions were applied to describe procedural and follow-up outcomes. Mortality at 6-month follow-up was evaluated.

We included 2002 patients. Overall age was 81 years [77, 85], 45.2% were female, EuroScore II was 4.22 [2.39, 7.60]. Age (p < 0.001), female sex (p < 0.001), diabetes (p < 0.001), peripheral artery disease (p = 0.002), myocardial infarction (p = 0.013), and creatinine (p = 0.001) were associated with tortuosity. Adjusted 6-month analysis showed that TI > 1.50 was associated with increased mortality [hazard ratio (HR) 1.679, 95% CI (1.098-2.567), p = 0.017].

TI > 1.50 may determine a higher-risk population in patients undergoing Tf-TAVI. Further study is required to validate our findings.