Magnetic resonance assessment of left ventricular diastolic dysfunction for detecting cardiac allograft vasculopathy in recipients of heart transplants

Cardiac allograft vasculopathy (CAV) is a major late complication in heart transplant recipients, graded based on intravascular ultrasound (IVUS), and accelerates left ventricular (LV) diastolic dysfunction. We investigated the clinical feasibility of using magnetic resonance (MR) to assess LV diastolic dysfunction noninvasively in transplant recipients. Thirty-eight asymptomatic recipients (25 men, 37.2 ± 14.9 years) underwent both IVUS and cardiac MR. Based on IVUS, we divided the individuals into 2 groups using Stanford classification to categorize CAV development as either nonsignificant or advanced. We measured LV peak filling rate (PFR) and systolic function parameters, including LV ejection fraction (EF), stroke volume (SV), and cardiac output (CO) using cine MR; compared those values between groups; calculated receiver operating characteristic curve in the relationship between PFR value and CAV; and assessed myocardial late gadolinium enhancement (LGE) on contrast-enhanced MR. We classified CAV as advanced in 20 patients (53%) and nonsignificant in 18 (47%). LV EF, SV, and CO values were not significantly different. PFR was significantly lower in the advanced (3.63 ± 0.90 EDV/s) than nonsignificant group (4.43 ± 0.84 EDV/s, P = 0.01). The area under the curve was 0.76. We observed no myocardial LGE. MR measurement of PFR may permit noninvasive assessment of diastolic dysfunction associated with CAV before LV systolic dysfunction and myocardial infarction or scar formation develop.