Assessment and Characterization of Time-related Differences in Plaque Composition by Intravascular Ultrasound–derived Radiofrequency Analysis in Heart Transplant Recipients

Abstract

The survival of heart transplant patients is limited by cardiac allograft vasculopathy (CAV). Intravascular ultrasound (IVUS) and IVUS-derived radiofrequency plaque composition analysis (IVUS-RF) provide further information about the process of coronary atherosclerosis. In this study we aimed to assess the time-dependent differences in disease progression in patients with CAV. Fifty-six patients were divided into three groups according to time interval after transplantation (Group I: 1 to 3 months, 18 patients; Group II, 1 to 5 years, 20 patients; Group III: 5 to 15 years, 18 patients). IVUS-RF revealed time-dependent increases in all plaque components. The largest increase was shown for fibrotic, fibrofatty and necrotic tissue between Groups I and II. Dense calcium area increased uniformly in all groups. IVUS-RF-derived plaque type analysis revealed predominantly fibrotic plaques in all groups with a decrease of frequency over time. Fibrolipidic and fibrotic-calcific plaques increased uniformly. High-risk lesions, such as thick-cap fibroatheromas (FAs), increased in Groups I and II and decreased in Group III. Thin-cap FAs were detected only in Group III. IVUS-RF, as compared with gray-scale IVUS, provides better detailed information about the development of CAV by plaque morphology and composition analysis in different stages after heart transplantation. Serial IVUS-RF analysis in these patients may improve the stratification of heart transplant recipients.