Cardiac involvement in acromegaly: specific myocardiopathy or consequence of systemic hypertension?

Abstract

To evaluate the relative contributions of past or present GH hypersecretion and of hypertension to the cardiac abnormalities present in acromegaly, we have studied the serum GH and insulin-like growth factor I concentrations, systolic and diastolic blood pressures, and morphological and functional cardiac indexes as measured by echocardiography-Doppler, in 39 patients with active or cured acromegaly, 16 hypertensive controls, and 17 normotensive controls. Hypertension was present in 42.8% of patients with active acromegaly and in 28.0% of patients in which acromegaly was cured. Hypertension was independently related to an increase in indexes of cardiac morphology (left ventricular mass, left ventricular posterior wall thickness, interventricular septum thickness, relative wall thickness with respect to the diastolic diameter of the left ventricle, and left atrial end-systolic diameter), systolic function (stroke volume, fractional shortening, and end-systolic stress), and diastolic function (isovolumic relaxation time and maximal late diastolic flow velocity) and to a reduction in the early to late maximal diastolic flow velocity ratio. Acromegaly was related to an increase in left ventricular mass, stroke volume, cardiac output, and isovolumic relaxation time, which were independent from the presence of hypertension. End-systolic stress was reduced by acromegaly. In the five patients in which active acromegaly was successfully treated, left ventricular mass and left ventricular posterior wall thickness were reduced 1 yr later. In conclusion, the asymptomatic morphological and functional cardiac abnormalities present in acromegalic patients are independently related to acromegaly and hypertension, pointing to the existence to a specific acromegalic myocardiopathy that might be aggravated by the coexistence of hypertension.