BACKGROUND: The clinical implications of hypoattenuating leaflet thickening (HALT) and its potential link to thrombosis detected via computed tomography (CT) scans in post transcatheter pulmonary valve replacement (TPVR) patients are unknown. In this study we aimed to explore the prevalence, heart function, valvular hemodynamics, and early outcomes of HALT after TPVR. METHODS: We studied 64 of 76 consecutive multicentre patients who underwent TPVR, with the implantation of a Venus-P device (Venus MedTech Inc, Hangzhou, China). CT characteristics within a year, echocardiographic data, and early-term clinical end points were analyzed in patients with and without HALT. RESULTS: CT scans revealed HALT in 28 patients (56%) and reduced leaflet motion in 11 patients (20.8%) within 1 year (median interval, 184 [interquartile range, 104-214] days). HALT patients exhibited a lower percentage of normal tricuspid annular plane systolic excursion at the CT scan time (58.3% vs 73.7%
P = 0.020), although valvular hemodynamics and clinical end points were similar. Older age at intervention (odds ratio, 1.05
95% confidence interval, 1.01-1.09) and larger body mass index (odds ratio, 1.17
95% confidence interval, 1.01-1.36) were associated with HALT, whereas the use of anticoagulation was not identified as a protective factor. The HALT severity was positively correlated with the degree of leaflet motion (r = 0.67 and 0.69, respectively). CONCLUSIONS: HALT was highly prevalent, although it was subclinical. Early follow-up showed uneventful valvular hemodynamics and clinical outcomes. However, the HALT group exhibited suboptimal right ventricular function during CT scans, with older age and higher body mass index linked to this issue.