Usefulness of left ventricular diastolic function assessed by magnetic resonance imaging over invasive coronary flow reserve measurement for detecting cardiac allograft vasculopathy in heart transplant recipients.

Heart transplant recipients undergo annual screening of early-stage cardiac allograft vasculopathy (CAV) by invasive coronary flow reserve (CFR) measurement. We compared the sensitivity for CAV detection between the CFR measurement and noninvasive magnetic resonance (MR) assessment of left ventricular (LV) diastolic function. In 46 asymptomatic recipients (29 men, aged 35.2 ± 16.1 years) 7.9 ± 4.3 years after transplantation, we measured LV peak filling rate (PFR) using cine MR and CFR in the left anterior descending artery by Doppler guidewire; classified recipients of class 0-2 as negative for CAV and class 3-4, positive, according to Stanford classification assessed by IVUS; compared those values between the 2 groups; and calculated receiver operating characteristic curve in the relationship between PFR value and CAV. We classified 20 recipients (43%) positive and 26 (57%) negative for CAV. Although there was no significant difference in CFR value, the PFR value was significantly lower in the positive (3.54 ± 0.84 EDV/s) than in negative group (4.39 ± 0.85 EDV/s, P = 0.002). Area under the curve was 0.78, and the sensitivity was 78% and specificity, 61%, when PFR cut-off value was 4.20. MR PFR measurement provides noninvasive prediction of CAV, preceding impaired CFR in asymptomatic recipients.