Clinicopathological Significance of Microvasculopathy after Heart Transplantation.
Li Li, Hongyue Wang, Laifeng Song, Yong Guo, Jian Zhang, Jie Huang, Hong Zhao. Chinese Academy of Medical Sciences, Peking Union Medical College, Cardiovascular Institute, Fu Wai Hospital, Beijing, China
Background: Stenotic microvasculopathy is common after heart transplantation; however, the associated risk factors and predictive value of stenotic microvasculopathy after heart transplantation for the development of cardiac allograft epicardial vasculopathy and reduced cardiac function are still unclear and controversial.
Design: 278 endomyocardial biopsy specimens were harvested from 64 patients one year later after heart transplantation. Light microscopic evaluations were performed for microvasculopathy, defined as stenotic endothelial and/or medial disease. Epicardial vasculopathy was evaluated by coronary angiography, and/or intravascular ultrasound. The relationship between stenotic microvasculopathy and eipcardial vasculopathy, cardiac function, recipient age, times of acute cellular rejection and grade, Quilty lesion, coronary atherosclerosis, and diabetes mellitus was also investigated.
Results: Stenotic microvasculopathy was present in 38 of 64 patients (59%) and was due to medial (30/38; 79%) rather than endothelial disease (2/38; 5%) or a combination of both (6/38; 16%, P<0.001). Patients with stenotic microvasculopathy were younger than that without stenotic microvasculopathy (40.68±15.85 vs 49.42±8.67, P=0.013). The numbers of acute cellular rejection (0.64±0.43 vs 0.37±0.32, P<0.001) and ≥ grade 2 acute rejection (0.84±0.16 vs 0.23±0.10, P=0.007) were greater in stenotic microvasculopathy group compared to that of non-stenotic group. Multivariate regression analysis demonstrated that the recipient age (r=-0.05, P<0.001) and acute rejection grade (r=3.40, P<0.001), rather than Quilty lesion, coronary atherosclerosis, and diabetes mellitus are significant risk factors for developing microvasculopathy after heart transplantation. Microvasculopathy observed in endomyocardial biopsies after heart transplantation was not related to epicardial vasculopathy and reduced cardiac dysfunction.
Conclusions: Microvasculopathy is a frequent immune-mediated event after heart transplantation. The occurrence of microvasculopathy is not a predictive index for developing allograft epicardial vasculopathy and worsening cardiac function. The clinicopathological significance of long term observation of microvasculopathy after heart transplantation is warranted.
Wednesday, March 2, 2011 1:00 PM
Poster Session VI # 48, Wednesday Afternoon