Abstract 18037: Early Coronary Microvascular Dysfunction Due to Primary Hyperparathyroidism: The First Step Leading to Their Increased Cardiovascular Risk?
Objective: Primary hyperparathyroidism (pHPT) increases the risk for myocardial infarction (MI). We evaluated coronary flow reserve (CFR) by transthoracic Doppler echocardiography (TDE), as an index of coronary microvascular function, in pHPT.
Methods: 100 pHPT patients (pts) (80 F, aged 58±12 years) without clinical evidence of heart disease, and 50 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 from pHPT diagnosis was 6 months (range 1–109).
Results: In pHPT pts, CFR was lower than in controls (3.0±0.8 vs 3.6±0.7, p<0.0001) (Figure A). CFR was ≤2.5 in 27 (27%) pts compared with controls (4%) (p<0.0001). CFR was inversely related to parathyroid hormone (PTH) levels (Figure B). In pts with CFR ≤2.5, PTH was higher (410 ±95 vs 207±16 ng/L, p=0.01) while calcium levels were similar (2.7±0.2 vs 2.9±1 mmol/L, p=0.7). At multivariable linear regression analysis adjusted for age, gender and cardiovascular risk factors, PHT and age were the only determinants of CFR (PHT β=−0.230, p=0.03; age β=−0.272, p=0.01 respectively). At multiple logistic regression analysis only PHT increased the probability of CFR ≤2.5 (OR 2.5, p=0.03). Out of 27 pHPT pts with pre-operative CFR ≤2.5, 19 pts evaluated 6months after parathyroidectomy showed a complete CFR normalization (CFR 2.1±0.5 vs 3.3±0.7 p<0.0001, respectively).
Conclusions: Coronary microvascular function is impaired by pHPT and promptly restored after parathyroidectomy. PTH independently correlates with abnormal CFR, suggesting a detrimental effect on coronary microcirculation that may contribute to the increased cardiovascular risk of pHPT.
- © 2010 by American Heart Association, Inc.