MAGNETIC-RESONANCE CORONARY ANGIOGRAPHY IN HEART-TRANSPLANT RECIPIENTS

Background: Annual coronary angiography is routinely performed to eval uate cardiac allografts. Recently, magnetic resonance coronary angiogr aphy has been used to imagine native coronary arteries, but its use in transplant recipients, with rapid heart rates, metallic sternal sutur es, and altered cardiac orientation, has not been described. Our goal was to describe the feasibility of noninvasive magnetic resonance coro nary angiography in cardiac allograft recipients, detect flow-limiting focal stenoses, and quantify the altered coronary artery orientation. Methods and Results: We performed magnetic resonance coronary angiogr aphy in 18 adult heart transplant recipients (15 men and 3 women) with use of a breath-hold EGG-gated segmented k-space technique. Multiple transverse and oblique images were obtained in each subject. A control population of 16 adult patients without transplant and without angiog raphic evidence of coronary disease provided a reference for the coron ary artery length visualized by magnetic resonance coronary angiograph y. This technique identified the left main coronary artery in 15 of 15 transplant recipients with normal coronary anatomy. Magnetic resonanc e coronary angiography demonstrated a +25-degree anterior (clockwise) right coronary artery ostial rotation in transplant recipients (p = 0. 0001 versus control group) with corresponding realignment of the left main ostium. By magnetic resonance coronary angiography, the mean cont iguous length of coronary artery visualized in the transplant recipien ts was similar to that in the control subjects for all major vessels ( p = not significant). Five transplant recipients had nine discrete ste noses (50% or greater luminal diameter) identified by contrast angiogr aphy, of which seven stenoses were identified as signal voids by magne tic resonance coronary angiography. Coronary stenoses not seen by this technique were located in the distal one third of the artery. Conclus ions: These data confirm and for the first time quantify the previousl y observed anterior rotation of the coronary ostia, which may be used to guide coronary engagement for subsequent interventions. In addition , these data demonstrate the potential of magnetic resonance coronary angiography to image noninvasively the coronary arteries and identify focal stenoses in cardiac allograft recipients.