Pre-interventional renal artery calcification and survival after transcatheter aortic valve implantation.

Abstract

The prognostic significance of renal artery calcification (RAC) is unknown in patients with severe aortic stenosis (AS) eligible for transcatheter aortic valve implantation (TAVI). RAC can be assessed by computed tomography (CT) performed during pre-interventional planning for TAVI. This study aimed at investigating the utility of RAC for predicting survival after TAVI. In this longitudinal cohort study, RAC volume was measured by CT in 268 consecutive patients with severe AS undergoing TAVI. Association of RAC with mortality was assessed using Cox regression analysis. RAC was evaluated as a binary parameter and in a supplementary analysis as a logarithmically transformed continuous variable. Over a median follow-up time of 9.6 years, 237 (88.4%) patients died, with 174 (73.4%) deaths attributable to a cardiovascular cause. RAC was highly prevalent (N = 150 (86.2%)) among patients suffering cardiovascular death. Competing risk cumulative incidence curves revealed a higher occurrence of cardiovascular death in patients with RAC (P-value = 0.008), while this was not the case for non-cardiovascular death (P-value = 0.71). RAC was independently associated with cardiovascular death (HR 1.61 [95% CI: 1.01-2.57]; P = 0.047) after adjustment for age, sex, cardiovascular risk factors, impaired renal function, and aortic valve calcification. The presence or absence of RAC rather than its volume was important in all the analyses. RAC is a strong and independent predictor of cardiovascular death in patients with severe AS undergoing TAVI. Given its favourable properties for event prediction, RAC may be considered valuable for prognostic assessment of TAVI patients.