Spatial analysis and factors associated with transcatheter aortic valve implantation in Portugal: a retrospective analysis from 2015 to 2017

Objectives: To identify the factors associated with transcatheter aortic valve implantation (TAVI) use of TAVI in inpatients with aortic stenosis (AS) in Portugal and its geographical distribution. Methods: A quantitative, observational and retrospective study using the Portuguese National Health Service inpatient discharge database from 2015 to 2017. Surgical aortic valve replacement (SAVR) and TAVI procedures were selected using the International Classification of Diseases. First, we mapped the yearly age-standardised rate for each procedure using QGIS. Then, we performed χ2 tests, independent t-tests and logistic regressions to study the factors associated with TAVI use. Results: From 2015 to 2017, 8398 hospitalisations were selected, 88.5% SAVR and 11.5% TAVI. From 2015 to 2017, SAVR use increased in the Northern region and decreased in the Lisbon region, while the opposite was observed for TAVI. TAVI was performed among the most complex (p<0.001) and older patients (the mean (SD) age for SAVR was 70 (±11) years old and 81 (±7) years old for TAVI, p<0.001). The results for the logistic regressions showed that, more recent hospitalisations, being older, living in the Lisbon region and having a higher Charlson Comorbidity Index was associated with an increased likelihood of undergoing TAVI (p<0.001). Conclusions: TAVI increased over the years. TAVI is more often performed in more severe patients as an alternative to SAVR with similar discharge outcomes. These results suggest the existence of geographic disparities in the availability and access to healthcare services and technologies.