Residual shear stress following transcatheter aortic valve replacement is associated with rehospitalization for heart failure

Backgrounds Transcatheter aortic valve replacement (TAVR) improves hemodynamic disturbances in severe aortic stenosis (AS). Several translational studies have highlighted shear stress-induced inflammation, oxidative stress and primary hemostasis disorder in AS, as well as their improvement following TAVR. However, the relationship between residual shear stress and TAVR outcomes remains unclear. Purpose This study aimed to evaluate the impact of residual shear rate after the deployment of transcatheter heart valve (THV) on heart failure (HF) following TAVR. Methods A total of 939 patients with available data of shear rate after the THV deployment were included in the analysis from our prospective registry. Patients undergoing TAVR for aortic regurgitation and valve-in-valve procedures were excluded. Shear rate before and after the THV deployment were calculated using echocardiography as: 4×max aortic valve velocity/√(aortic valve area [AVA] or effective orifice area [EOA]/π). The primary endpoint was 2-year HF following TAVR, which was classified as early (≤30 days) and late events (>30 days). ROC curve analysis was used to derive the cut-off value of post-shear rate for the prediction of 2-year HF. Results Shear rate values significantly decreased from pre-TAVR to post-procedure (3634±865 s⁻¹ vs. 925±352 s⁻¹, p<0.0001). 147 patients (16%) experienced HF at 2 years following TAVR. The optimal threshold of post-shear rate for predicting 2-year HF was 822.4 s⁻¹. Patients with a post-shear rate >822.4 s⁻¹ (n=528, 56%) were more likely to be women, with a lower incidence of dyslipidemia, smaller aortic annulus and AVA, higher aortic gradient, and a higher proportion of balloon-expandable valve (BEV) use. These patients also had a smaller EOA and a higher rate of impaired THV performance at discharge compared to those with a lower post-shear rate (n=411, 44%). Patients with a post-shear rate >822.4 s⁻¹ had a higher incidence of 2-year HF (21.2% vs. 11.0%, log-rank p<0.0001), primarily driven by an increased incidence of late HF (20.0% vs. 10.1%, log-rank p<0.0001), rather than early HF (1.5% vs. 1.0%, log-rank p=0.49) (Fig. 1A and 1B). In multivariate analysis, adjusted for age, sex, CKD, atrial fibrillation, LVEF <40%, impaired THV performance, and HF medications, a post- TAVR shear rate >822.4 s⁻¹ was independently associated with late HF and 2-year HF (aHR, 2.23, 95% CI, 1.52–3.28 and aHR, 2.16, 95% CI, 1.50–3.12, respectively). In both patients receiving BEVs and those receiving self-expandable valves (SEVs), those with a post-shear rate >822.4 s⁻¹ had smaller THVs and a higher incidence of 2-year HF (21.0% vs. 12.5%, log-rank p=0.015 and 21.7% vs. 9.6%, log-rank p=0.0023, respectively) (Fig. 2A and 2B). Conclusions Post-TAVR residual shear rate, regardless of valve type, is a critical determinant of late HF. Potential pathophysiological mechanisms may include early structural valve deterioration due to subclinical thrombosis or inflammation.