Objectives: The aim of this study was to characterize progression of cardiac allograft vasculopathy (CAV) with special respect to coronary artery geometry.
Background: As previously shown by intravascular ultrasound (IVUS), CAV is characterized by a multifocal intimal hyperplasia. Little is known, however, about vascular remodeling processes influencing vessel geometry and luminal narrowing.
Methods: In 30 heart transplant recipients serial IVUS studies were performed at baseline (BL) and after a mean follow-up period of 12.5+/-2.5 months. Changes in plaque, lumen and vessel volume were assessed in the proximal left anterior descending artery. Pattern of remodeling was analyzed in patients "early" (n = 15, BL study 1.4+/-0.7 months after heart transplantation [HTX]) compared with "late" after HTX (n = 15, BL 46.1+/-29.1 months).
Results: Plaque volume was found to increase by a mean of 23.8+/-25.9 mm3, not significantly different within and beyond the 1st year after HTX. Significant differences, however, were observed in changes in vessel volume with a mean decrease of -52.8+/-70.9 mm3 in the early group, whereas late follow-up group presented with an enlargement of 32.3+/-46.0 mm3. Based on these changes, lumen volume decreased by -73.2+/-69.8 mm3 early, in contrast to a slight increase of 5.2+/-32.6 mm3 in the late group.
Conclusions: Progression of CAV is a complex process, modified by changes in the vascular geometry. Especially within the 1st year after HTX, luminal loss is influenced not only by an increase in plaque area but by a decrease in total vessel volume as well.