Endocrine Abstracts

There is evidence for a strong association between Cushing’s syndrome, characterized by a cluster of systemic complications, and increased cardiovascular risk. To our knowledge, coronary circulatory function has not been explored in Cushing’s syndrome. The aim of the study was to evaluate coronary flow reserve (CFR), an index of coronary microvascular function, in patients with Cushing’s syndrome. Thirteen newly diagnosed patients with Cushing’s syndrome (12 F/1M; mean age 42.3±9.9 years), were selected for having no clinical evidence of ischemic heart disease. There were 11 cases of pituitary-dependent Cushing’s disease and two of cortisol-producing adrenal adenoma. Thirteen subjects matched for age, sex, and major cardiovascular risk factors were used as controls. Coronary flow velocity in the left anterior descending coronary artery was investigated by transthoracic Doppler echocardiography at rest and during adenosine infusion. CFR was obtained as the ratio hyperaemic/resting diastolic flow velocity. Mean CFR was similar in patients with Cushing’s syndrome and controls (2.9±0.4 vs 3.1±1.4, P NS). A reduced coronary reserve (hyperaemic/resting ratio ≤2.5) was found in 4/12 (30.7%) Cushing patients and in 4/12 controls. In all patients with abnormal CFR epicardial coronary stenosis was excluded by multi-slice CT coronary angiography. CFR was inversely related to urinary cortisol levels in patients with endogenous hypercortisolism (Spearman’s ρ=−0.63, P=0.02) while no correlation was found in control subjects.

Conclusions: Coronary microvascular function, as assessed by CFR, is reduced in a considerable proportion of patients with Cushing’s syndrome without clinical evidence of ischemic heart disease. The relationship between CFR and cortisol may contribute to explain the increased risk of cardiovascular mortality in Cushing’s syndrome. Whether exposure to excess cortisol (possibly linked to duration of disease) may have per se a pathogenic role on coronary dysfunction, requires further studies.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.