Optical coherence tomographic evaluation of transplant coronary artery vasculopathy with correlation to cellular rejection

Background-Cardiac allograft vasculopathy is an accelerated fibroproliferative process that affects the coronary arteries of transplanted hearts. Intracoronary imaging with optical coherence tomography enables detection of subangiographic cardiac allograft vasculopathy. Methods and Results-At the time of routine surveillance coronary angiography, 48 consecutive heart transplant recipients underwent optical coherence tomographic imaging of 1 coronary artery. Imaging findings were compared per rejection history that was graded according to the International Society of Heart and Lung Transplantation classification as none/ mild (International Society of Heart and Lung Transplantation 0, 1A/1B, or 2) or high-grade rejection (=3A). Compared with the none/mild rejection group (37 patients) using Mann-Whitney U test, patients in the high-grade rejection group (11 patients) had a thicker intima in all coronary segments (distal: 0.22 mm [0.09-0.41] versus 0.09 mm [0.06-0.17], P=0.02; middle: 0.35 mm [0.00-0.45] versus 0.14 mm [0.08-0.24], P=0.002; and proximal: 0.34 mm [0.21-0.44] versus 0.15 mm [0.11-0.21], P=0.005) and a higher prevalence of foamy macrophages (distal: 55% versus 9%, P=0.003; middle: 55% versus 22%, P=0.004; and proximal: 44% versus 13%, P=0.05) using ?2 statistics. Side branches in the high-grade rejection group had smaller lumen diameters and a higher prevalence of intimal thickening (54% versus 36%; P=0.01). Intimal microvessels were also more prevalent in the high-grade rejection group versus the none/mild rejection group (46% versus 11%; P=0.02). Conclusions-Coronary optical coherence tomographic evaluation revealed that patients with a history of high-grade cellular rejection, compared with those with none/mild rejection, had more coronary artery intimal thickening with macrophage infiltration, involving all coronary segments and side branches. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01403142.