Intravascular Ultrasonic Imaging of Coronary Arterial Remodeling in Heart Transplant Recipients

The purpose of this study was to evaluate long-term changes of transplant coronary arteries, including vessel, plaque, and lumen areas. There are limited long-term data on vessel remodeling after heart transplantation. We analyzed serial intravascular ultrasound images of the left anterior descending coronary artery (LAD) in 54 heart transplantation recipients. Nine patients (16.7%) had a history of rejection. Proximal left anterior descending artery segments were matched among time points, a ≥20-mm long segment was analyzed every 1 mm, and results were normalized for analysis length and reported as mm³/mm. During follow-up, vessel area decreased (-0.48 ± 1.3 mm³/mm/year), and plaque area did not change (-0.01 ± 0.47 mm³/mm/year). As a result, lumen area decreased (-0.52 ± 1.34 mm³/mm/year). The change in mean lumen area was well correlated to the change in mean vessel area (r = 0.94, p <0.01) but not to the change in mean plaque area (r = -0.27, p = 0.05). In conclusion, lumen loss occurred during long-term follow-up of patients who underwent heart transplantation, primarily secondary to negative remodeling (decrease in vessel dimensions).