Impact of balloon-expandable valve asymmetry index on heart failure following transcatheter aortic valve replacement

Abstract Backgrounds Asymmetrical expansion of balloon-expandable valve (BEV) has been linked with impaired hemodynamic valve performance following transcatheter aortic valve replacement (TAVR). However, the impact of asymmetrical expansion on heart failure (HF) following TAVR remains unknown. Purpose This study aimed to evaluate the association between asymmetrical expansion of BEV and HF following TAVR. Methods Among 607 patients who undergoing TAVR with BEV between February 2015 and May 2019 in our prospective registry, 589 were included in the analysis. Asymmetry index was defined as: (longer height/shorter height of BEV) − 1 × 100, which was measured using freeze-frame fluoroscopic images after the deployment of BEV (Figure 1). The primary endpoint was 2-year HF following TAVR, which was further classified as early (≤30 days) and late events (30 days post-TAVR). Receiver operating characteristic curve analysis was used to derive the cut-off value of asymmetry index for the prediction of 2-year HF. Patients were assigned to two groups according to the cut-off value of asymmetry index. Results Ninety-nine patients (17%) experienced HF at 2 years post-TAVR. The optimal threshold of asymmetry index for predicting 2-year HF was 7.48. Patients with asymmetry index 7.48 had larger aortic annulus (diameter, 25.1 ± 2.6 mm vs. 24.5 ± 2.3 mm, p=0.0049; area, 502 ± 105 mm2 vs. 475 ± 92 mm2, p=0.0039) and higher aortic calcium score (3812 ± 1988 AU vs. 3057 ± 1374 AU, p=0.0008) compared with those without. In our population, there was no significant difference in impaired valve performance at discharge, which was defined as mean transvalvular gradient ≥20 mmHg and/or ≥moderate aortic valve regurgitation, between the two groups (7% vs. 8%, p=0.58). Patients with an asymmetry index 7.48 had a higher cumulative incidence of 2-year HF compared to those without (23.6% vs. 15.8%, log-rank p=0.043), primarily driven by an increased incidence of late HF (22.7% vs. 14.1%, log-rank p=0.019), rather than early HF (1.2% vs. 2.0%, log-rank p=0.52) (Figure 2A and 2B). In multivariate Cox regression analysis, adjusted for chronic kidney disease, atrial fibrillation, left ventricular ejection fraction 40%, and HF medications, an asymmetry index 7.48 was independently associated with late HF (hazard ratio, 1.63; 95% CI, 1.06–2.51). Conclusions Asymmetrical expansion of BEV was strongly associated with late HF following TAVR. While this asymmetry has been linked to structural valve deterioration and leaflet thrombosis in previous studies, further investigation is needed to fully delineate the precise pathophysiological mechanisms involved.Figure 1 Figure 2