Abstract 16540: Coronary Microvascular Dysfunction is an Independent Predictor of Epicardial Allograft Vasculopathy Onset and Mortality in Heart Transplant Patients With Normal Coronary Angiograms
Background: Cardiac allograft vasculopathy (CAV) continues to limit the long-term survival of heart transplant (HT) recipients. Microvascular dysfunction is emerging as a strong predictor of outcome in HT patients. Early detection of CAV is important because it may allow alterations in medical therapy. We aimed to assess the validity of microvascular dysfunction, defined as a reduced coronary flow reserve (CFR), as a predictor of epicardial allograft vasculopathy or death.
Methods: We studied 105 patients (pts) (78 males, aged 52±12 years at HT) at 4±1 years post-HT with normal coronary angiography (CA). CAV new onset was assessed by CA. CFR was assessed in the left anterior descending coronary artery by transthoracic Doppler echocardiography (TDE) and calculated as the ratio of hyperemic to basal blood flow velocity. CFR≤ 2.5 was considered abnormal. Follow up was 10 years, and CA was repeated every 2 years.
Results: CAV new onset was diagnosed in 30 pts (28.6%) (Group A), CA was normal in 75 pts (71.4%) (Group B). Group A had lower CFR than group B (2.4 ± 0.6 vs 3.2 ± 0.7, p<0.0001). CFR≤2.5 was independently associated with a higher probability of CAV new onset at 10 years after HT (HR 4.8, 95% CI 2.1-10.2, p<0.0001) (Figure A) and with a higher probability of death, regardless of CAV onset (HR 2.2, 95% CI 1.06-4.8, p<0.0008) (Figure B).
Conclusions: Microvascular dysfunction, defined as a CFR≤ 2.5 by TDE, is an independent predictor of epicardial allograft vasculopathy onset. Moreover, microvascular dysfunction seems to be associated with a higher likelihood of death, regardless of CAV onset.
- © 2013 by American Heart Association, Inc.