Porcelain aorta in TAVI: predictor of adverse outcomes or an overestimated risk factor?

Abstract Background Patients with a porcelain aorta (PA) present a significant surgical challenge when aortic valve replacement (AVR) is indicated, rendering transcatheter aortic valve implantation (TAVI) a preferable option to surgery. Few studies have described the impact of PA within the TAVI population; as such, we reviewed our institutional TAVI experience over 9 years and aimed to analyze whether PA is an independent risk factor for worse postoperative outcomes and prognosis in TAVI. Objective To characterize the outcomes of patients with PA undergoing TAVI as compared to the general TAVI population. Methods Consecutive patients undergoing TAVI at a single institution between 1/1/2012-1/1/2021 were included. Based on the extent of circumferential calcification of the ascending aorta, patients were classified as either porcelain aorta (PA) or no porcelain aorta (NP). The primary endpoints were in-hospital all-cause mortality and stroke. Secondary endpoints included: in-hospital length of stay (ihLOS), intensive care unit hours (ICUh), renal failure, aortic valve (AV) reintervention, and echo- and electrocardiographic data. To adjust for preoperative differences, inverse probability of treatment weighting (IPTW) was applied, and standardized mean differences (SMDs) were assessed to ensure adequate covariate balance, with a threshold of SMD0.1 indicating successful adjustment. Univariate logistic regression was performed for baseline characteristics with post-IPTW SMD0.1. Results A total of 2732 patients were identified, of whom 57 (2%) had PA. Table 1 shows patients’ baseline characteristics. Compared to the NP cohort, PA patients were more likely to be younger (p0.001), female (p=0.211), and have heart failure symptoms (p=0.022). Preoperatively, PA patients had a smaller AV annular size (p=0.017), and lower mean gradient (p=0.037). Following adjustment by IPTW and logistic regression (Table 2), no significant differences were observed in the rates of mortality (OR=0; p=0.984), stroke (OR=1.102; 95% CI: 0.148,8.169; p=0.924), postoperative creatinine (Coef. = -0.118; 95% CI: -0.497,0.261; p=0.543) or reintervention for AV disease (OR=0; p=0.991). Moreover, compared to NC, PA patients had similar rates of ihLOS (Coef. = 1.655; 95% CI: -1.124,4.433; p = 0.243) and ICUh (Coef. = 16.930; 95% CI: -12.264,46.120; p=0.256). Pre-discharge echocardiographic measurements demonstrated significantly higher peak velocity (Coef. = -0.222; 95% CI: -0.445,0.0; p=0.050) and mean AV gradient (Coef. = -2.506; 95% CI: -4.377,0.634; p=0.009). Conclusions In the setting of TAVI, PA does not appear to confer additional risk of mortality, stroke, or renal failure, nor longer postoperative in-hospital and ICU lengths of stays. However, PA was associated with differing echocardiographic results post-TAVI. This indicates that TAVI is a safe and effective method of AVR when significant circumferential atherosclerotic aortic calcification precludes a safe cross clamp.T1: Baseline characteristics. T2: Adjusted linear regression analysis.