Abstract 11831: Geographic Distribution of Cardiac Allograft Vasculopathy Associated With Acute Cellular Rejection: A Serial Three-Dimensional IVUS Study of Heart Transplant Recipients
Background: Cardiac allograft vasculopathy (CAV) results from cumulative arterial injury induced by a combination of alloimmune responses and non-specific insults in the context of impaired repair mechanisms. This study aimed to characterize early arterial responses and geographic distribution of CAV associated with acute cellular rejection in heart transplant recipients.
Methods: We studied 92 heart transplant recipients who underwent baseline (4-6 weeks post-transplant) and 1-year intravascular ultrasound (IVUS) in the first 50 mm of the left anterior descending (LAD) coronary artery. Average intimal thickness and volumetric IVUS indices for vessel and intima were obtained in 3 equally divided subsegments (proximal, middle, and distal), respectively. Paradoxical arterial remodeling over time was defined as [[Unable to Display Character: ∆]]vessel volume / [[Unable to Display Character: ∆]]intimal volume <0. Acute cellular rejection was defined by endomyocardial biopsy as ISHLT Grade ≥2R.
Results: During the first year after transplant, 28 patients (30%) had ≥1 episode of acute cellular rejection. Overall, patients with rejection showed greater intimal growth (p<0.01) but equivalent paradoxical remodeling compared with non-rejectors. In segmental analysis, intimal growth in rejection patients was diffusely distributed along the LAD artery, while non-rejectors showed a predilection toward the proximal segment (left figure). As a result, a significant difference in intimal thickening was observed predominantly at the distal segment. In contrast, paradoxical remodeling significantly differed exclusively at the proximal segment of the LAD artery (right figure).
Conclusions: Despite the diffuse vessel involvement of CAV with respect to intimal growth, the pathological arterial response to intimal growth associated with acute cell-mediated rejection appears to have geographic differences, predominantly affecting the proximal coronary artery.
Author Disclosures: K. Okada: None. H. Kitahara: None. H. Yang: None. H. Lim: None. K. Otagiri: None. S. Tanaka: None. Y. Kobayashi: None. P. Yock: None. A. Yeung: None. P. Fitzgerald: None. K. Khush: None. W. Fearon: None. Y. Honda: None.
- © 2014 by American Heart Association, Inc.