Coronary Microvascular Dysfunction Induced by Primary Hyperparathyroidism is Restored after Parathyroidectomy
Background—Symptomatic primary hyperparathyroidism (PHPT) is associated with increased cardiovascular mortality. However, data on the association between asymptomatic PHPT and cardiovascular risk are lacking. We assessed coronary flow reserve (CFR), as a marker of coronary microvascular function, in asymptomatic PHPT of recent onset.
Methods and Results—We studied 100 PHPT patients (pts) (80 F, aged 58±12 years) without cardiovascular disease, and 50 controls matched for age and gender. CFR in the left anterior descending coronary artery was detected by transthoracic Doppler echocardiography, at rest and during adenosine infusion. CFR was the ratio of hyperemic diastolic flow velocity (DFV) to resting DFV. In PHPT, CFR was lower than in controls (3.0±0.8 vs 3.8±0.7, p<0.0001). CFR was abnormal (≤2.5) in 27 (27%) pts compared with controls (4%) (p=0.0008). CFR was inversely related to parathyroid hormone (PTH) levels (r=-0.3; p<0.004). In pts with CFR ≤2.5 PTH was higher (26.4 [16-37] vs18. [13-25] pmol/L, p<0.007) whereas calcium levels were similar (2.9±0.1 vs 2.8±0.3 mmol/L, p=0.2). At multivariable linear regression analysis, PTH, age and heart rate were the only factors associated with CFR (p=0.04, p=0.01 and p=0.006, respectively). At multiple logistic regression analysis only PTH increased the probability of CFR ≤2.5 (p=0.03). In all PHPT pts with CFR ≤2.5, parathyroidectomy normalized CFR (3.3±0.7 vs 2.1±0.5, p<0.0001).
Conclusions—PHPT pts have coronary microvascular dysfunction which is completely restored after parathyroidectomy. PTH independently correlates with the coronary microvascular impairment, suggesting a crucial role of the hormone to explain the increased cardiovascular risk in PHPT.
- Received November 21, 2011.
- Accepted June 29, 2012.
- Copyright © 2012, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited