Hypoattenuated Leaflet Thickening After TAVR: Incidence, Predictors, and the Role of Platelet Reactivity: A Prospective Multicenter Observational Study.

Background/

Objectives

Hypoattenuated leaflet thrombosis (HALT) is a frequent finding after transcatheter aortic valve replacement (TAVR). Although high residual platelet reactivity (HPR) increases thrombotic risk after coronary stent implantation, its role in HALT remains unclear. This study aimed to determine the incidence and predictors of HALT in TAVR patients treated with dual antiplatelet therapy, focusing on the impact of HPR.

Methods

This was a prospective, multicenter observational study. Between June 2018 and February 2022 patients with symptomatic severe aortic stenosis undergoing successful TAVR and treated with dual antiplatelet therapy for 3 months were included. Platelet reactivity was assessed 1-3 months post-TAVR using either VerifyNow (72%) or the Multiplate Analyzer (28%). HALT was evaluated using contrast-enhanced multidetector computed tomography.

Results

A total of 169 patients were included (mean age 81.5 ± 5 years; 51% female). The incidence of HALT was 22%. Independent predictors of HALT were self-expanding valve (OR 3.05; 95% CI, 1.30-7.14; p = 0.010). Protective factors included larger prosthesis size (OR 0.78; 95% CI, 0.65-0.93; p = 0.007), statin-treated dyslipidemia (OR 0.37; 95% CI, 0.16-0.88; p = 0.024), and higher creatinine clearance (OR 0.98; 95% CI, 0.96-1.00; p = 0.035). HALT incidence was similar in patients with and without HPR (23.7% vs. 33.6%; p = 0.29). No differences in clinical outcomes were observed at 1 year.

Conclusions

HALT occurred in nearly one-quarter of TAVR patients treated with dual antiplatelet therapy and was unrelated to platelet reactivity. Valve characteristics, renal function, and statin-treated dyslipidemia were associated with HALT, highlighting the multifactorial nature of its development.