Early Post Heart Transplant Coronary Anatomic-Physiologic Characterization: ECAV Study

Abstract

<h3>Purpose</h3> Cardiac allograft vasculopathy (CAV) is a leading cause of mortality and graft failure after heart transplantation. Early detection of CAV and accurate prognostication are essential for development of novel therapies and tailored patient management. The goal of this prospective study is to characterize anatomic-physiologic alterations in the coronary vasculature in the first year of heart transplantation to determine coronary phenotypes and predictors of early CAV. <h3>Methods</h3> Consecutive adult heart transplant (HT) recipients were enrolled from 2 Canadian institutions between January 2018-March 2021 (NCT03217786). Participants underwent comprehensive coronary evaluation at 3- and 12- months post HT with invasive coronary angiography (ICA), intravascular ultrasound (IVUS), optical coherence tomography and measurements of fractional flow reserve, coronary flow reserve and the index of microcirculatory resistance. Additional assessments included serum biomarker testing, microvasculopathy evaluation on endomyocardial biopsy and myocardial blood flow quantification by cardiac positron emission tomography. CAV was defined on ICA according to the ISHLT CAV_0-3 grading scale. Rapidly progressive CAV was defined on IVUS as ≥0.5 mm increase in maximal intimal thickness between baseline and 12-month follow-up studies. <h3>Endpoints</h3> We will present data from 86 HT patients (baseline demographics in Table), phenotyping early post transplant longitudinal changes in the coronary intima (intimal volume, percentage intimal volume, plaque characteristics), vessel remodeling and hemodynamics. Regression analysis will be performed to identify coronary anatomic-physiologic predictors of rapidly progressive CAV. This data will determine the role of early post transplant invasive coronary assessments for early CAV detection and identify high-risk patients who may benefit from early therapeutic intervention and intensive surveillance.