Abstract 15998: Relation Between Periarterial Neovascularization and Progression of Coronary Allograft Vasculopathy: A Serial IVUS Study of Cardiac Transplant Patients
Background: A number of studies have correlated vasa vasorum proliferation with arterial inflammation and plaque progression. A recent study also reported that periarterial small vessels (PSV) were detected by IVUS more frequently in unstable vs. stable patients. This study aimed to evaluate the potential relationship between PSV assessed by IVUS and progression of coronary allograft vasculopathy after cardiac transplantation.
Methods: Serial (baseline and 2-year follow-up) IVUS was performed in 38 patients after successful cardiac transplantation. PSV were defined as echolucent luminal structures of <1 mm in diameter located within 2 mm from external elastic membrane (Figure A). The signal void structures were excluded when they connected to the coronary lumen (considered as side branches) or could not be followed in ≥3 contiguous frames. The number of PSV was counted in the first 30 mm of the left anterior descending artery at 1-mm intervals, and PSV score was calculated as the sum of cross-sectional values. Volume index (VI: volume/length, mm3/mm) was measured for vessel, lumen, and intima. Average intimal thickness (AIT) was also calculated for the entire analysis segment.
Results: Overall, 37 patients (97%) had PSV at either baseline or 2 years. PSV score at baseline was not significantly related to any IVUS parameters. At 2 years, however, the increase in PSV score from baseline to 2 years ([[Unable to Display Character: ⊿]]PSV score) positively correlated with the increase in intimal thickness ([[Unable to Display Character: ⊿]]AIT) (Figure B). Consequently, the higher [[Unable to Display Character: ⊿]]PSV score correlated with smaller lumen VI (r=-0.36, p=0.03) and greater intima VI (r=0.34, p=0.04) and AIT (r=0.44, p<0.01) at 2 years.
Conclusions: The increase in PSV from baseline to 2 years was related to progression of intimal thickening after cardiac transplantation. This may possibly represent an angioproliferative response around the coronary artery associated with coronary allograft vasculopathy.
- © 2013 by American Heart Association, Inc.