Clinical Implications of Leaflet Thrombosis After Percutaneous Pulmonary Valve Implantation With the Pulsta Valve: Life-Long Aspirin Is Necessary?

Background: Hypo-attenuated leaflet thickening (HALT) is a subclinical finding on cardiac computed tomography (CT) associated with leaflet thrombosis in bioprosthetic valves. However, its incidence and risk factors following percutaneous pulmonary valve implantation (PPVI) remain poorly characterized.

Aims: This study aimed to determine the incidence of HALT after PPVI and to identify clinical and procedural factors associated with its occurrence.

Methods: We conducted a retrospective review of patients who underwent PPVI with the Pulsta valve between January 2016 and December 2024 and underwent at least one follow-up cardiac CT by January 2025. Patients were stratified by the presence or absence of HALT. Clinical, procedural, and echocardiographic characteristics were compared, and multivariable logistic regression was performed to identify independent predictors of HALT.

Results: A total of 76 CT scans from 70 patients were analyzed. HALT was identified in 28 scans (36.8%) at a median of 3.1 years post-PPVI. Most cases were mild (≤ 25% leaflet thickening in 71.4%). Leaflet calcification was infrequent (2.6%). The majority of patients (82.9%) received aspirin monotherapy for 12 months, while 17.1% underwent prolonged dual antiplatelet therapy followed by long-term aspirin. Although not statistically significant, the prolonged regimen was associated with a numerically lower incidence of HALT. Larger valve size was independently associated with HALT (odds ratio 7.180; 95% confidence interval 1.054-48.891; p = 0.044).

Conclusions: HALT is a relatively common finding following PPVI, particularly in patients receiving short-term antiplatelet therapy and larger valve sizes. These findings support routine imaging surveillance and consideration of individualized antithrombotic strategies in post-PPVI management.