Science Minutes – Cardiology

Methodology for diagnosing hypo-attenuated leaflet thickening (HALT) and assessing its clinical relevance

A publication in the European Heart Journal Cardiovascular Imaging addresses the issue of transcatheter aortic valve implantation (TAVI). The summary of Dr. Júlia Karády, PhD student at Semmelweis University and first author of the publication highlights diagnostics of the complication of TAVI. As a known complication of TAVI, thrombotic plaques may form on prosthetic valve leaflets, which is visualized as hypoattenuated-leaflet thickening (HALT) on CT scans. No standard quantitative measurement method is available to evaluate the extent of HALT, and the clinical relevance of the presence or amount of HALT is also unknown. The aim of the research was to establish an objective, quantitative methodology for diagnosing HALT and assessing its clinical significance.

As part of the RETORIC (RulE out Transcatheter aOrtic valve thRombosis with post-Implantation Computed tomography) prospective cohort study, patients with TAVI were examined by cardiac CT, cardiac ultrasound, and cranial MRI at the Heart and Vascular Centre. With the help of the measurement method used by the research team for the first time, it was found that the extent of HALT detected by cardiac CT after TAVI strongly correlates with the deterioration of prosthetic valve function diagnosed by cardiac ultrasound. However, the amount of HALT did not correlate with the ischaemic brain lesions identified by MRI and all-cause death (median follow-up time was 2.5 years).