Abstract 12556: Coronary Microvascular Dysfunction in Patients With Acromegaly: A Hint for their Increased Cardiovascular Risk
Background: Acromegaly (AC) increases the risk of cardiovascular diseases. We evaluated coronary flow reserve (CFR) by transthoracic Doppler echocardiography (TDE), as an index of coronary microvascular function, in AC.
Methods: 40 AC patients (pts) (23 M, aged 52±11 years) without clinical evidence of heart disease, and 40 controls matched for age and gender were studied. Coronary flow velocity in the left anterior descending coronary artery was detected by TDE at rest and during adenosine infusion. CFR was the ratio of hyperaemic diastolic flow velocity (DFV) to resting DFV. A CFR≤2.5 was considered abnormal. The median time between the onset of symptoms and CFR assessment was 5 years (interquartile range 2-10 years).
Results: In AC pts, CFR was lower than in controls (2.9±0.8 vs 3.8±0.7, p≤0.0001) (Figure A). CFR was ≤2.5 in 13 (32.3%) pts compared with controls (0%) (p≤0.0001). CFR was inversely related to insulin-like growth factor 1 (IGF-1) levels (Figure B). In pts with CFR≤2.5, IGF-1 was higher (756 [381-898] vs 246 [186-484] μg/L, p≤0.004) while growth hormone (GH) levels were similar (6.3 [2.8-13.7] vs 5 [2.8-8.9] μg/L, p=0.8). At multivariable analysis adjusted for age, gender and other cardiovascular risk factors, IGF-1 was an independent determinant of CFR (β=-0.527, p≤0.0001) and a predictor of CFR≤2.5 (p=0.01).
Conclusions: Microvascular function is impaired in AC and is correlated with IGF-1 independently of GH levels, suggesting a negative effect of IGF-1 on coronary microcirculation that may contribute to the increased cardiovascular risk in AC.
- © 2013 by American Heart Association, Inc.