Stress Perfusion Cardiac Magnetic Resonance Imaging for the Diagnosis of Cardiac Allograft Vasculopathy

Cardiac allograft vasculopathy (CAV) is the leading cause of long-term mortality associated with heart transplantation (HTX). The early identification of CAV is imperative to prevent its onset and progression, as the only proven therapy for late stage CAV is re-transplantation. Because of the poor diagnostic performance of conventional noninvasive modalities for ischemia assessment (echocardiography, nuclear perfusion), current methods of CAV identification and monitoring rely primarily on invasive methods such as coronary angiography. Quantitative perfusion analysis using stress perfusion cardiac MRI (CMR) is a novel technique that can quantify myocardial blood flow (in mL/min/g) throughout the myocardium, making it a promising method for the noninvasive identification and serial monitoring of CAV. In addition to quantifying myocardial blood flow, a comprehensive CMR perfusion study can also quantify left ventricular function, myocardial edema (a marker of acute rejection), and myocardial fibrosis (a marker of irreversible myocardial injury). Using a single-center case control strategy, we will employ stress perfusion CMR to quantify myocardial blood flow in HTX patients with varying degrees of CAV. This project will be the first step towards developing and validating stress CMR perfusion for the early diagnosis and management of CAV to alter the natural history of the disease.