Reversal of myocardial fibrosis in patients with unilateral hyperaldosteronism receiving adrenalectomy

Abstract

Background: Primary aldosteronism is the most frequent cause of secondary hypertension and is associated with more prominent left ventricular hypertrophy and increased myocardial fibrosis. Unilateral hyperaldosteronism can be cured by adrenalectomy. However, the reversibility of cardiac fibrosis is still unclear.

Methods: We analyzed 11 patients prospectively with unilateral hyperaldosteronism (including 10 aldosterone-producing adenomas and 1 unilateral nodular hyperplasia) who received adrenalectomy from October 2006 to October 2007, and 17 patients with essential hypertension (EH) were enrolled as the control group. Echocardiography included ultrasonic tissue characterization by cyclic variation of integrated backscatter; it was performed in both groups and 1 year after operation in the unilateral hyperaldosteronism group.

Results: Patients with unilateral hyperaldosteronism had significantly higher diastolic blood pressure, higher plasma aldosterone concentration, lower serum potassium level, and lower plasma renin activity than patients with EH. In echocardiography, patients with unilateral hyperaldosteronism had thicker interventricular septal thickness, left ventricular posterior wall thickness, and higher left ventricular mass index than EH patients. Patients with unilateral hyperaldosteronism had significant lower cyclic variation of integrated backscatter than EH patients (7.1 ± 2.1 vs 8.7 ± 1.5 dB, P = .037). After analyzing the correlation of cyclic variation of integrated backscatter with clinical parameters for all participants, only log-transformed plasma renin activity was correlated significantly with cyclic variation of integrated backscatter. One year after adrenalectomy, interventricular septal thickness, left ventricular posterior wall thickness, and left ventricular mass index decreased significantly. In addition, cyclic variation of integrated backscatter increased significantly after adrenalectomy (7.1 ± 2.1 to 8.5 ± 1.5 dB, P = .02).

Conclusion: Adrenalectomy not only reversed left ventricular geometry but also altered myocardial texture in patients with unilateral hyperaldosteronism. This finding implies that increases in collagen content in the myocardium of patients with unilateral hyperaldosteronism might be reversed by adrenalectomy.