Regression of left ventricular hypertrophy in patients with primary aldosteronism/low-renin hypertension on low-dose spironolactone

Background. The incidence of left ventricular hypertrophy (LVH) in primary aldosteronism (PA) is higher than in essential hypertension. LVH is an independent cardiovascular risk factor. Treatment of PA with mineralocorticoid receptor blockers (MRBs) improves LVH. Previous studies included relatively small groups, low incidence of LVH and used high MRB dose. We tested the hypothesis that long-term regression of LVH in PA/low-renin hypertension may be achieved with low-dose MRB. Methods. Forty-eight patients (male/female 28/20, age 61.4 years, range 47-84) had PA (low renin, high aldosterone and high aldosterone/renin ratio, n = 24) or low-renin hypertension (low renin, normal aldosterone and high aldosterone/renin ratio, n = 24). All had either LVH or concentric remodelling. All had an echocardiogram both at baseline and at 1 year after the initiation of spironolactone. A subgroup of 29 patients had an echocardiogram at baseline, 1 year (range 0.5-1.5) and 3 years (range 1.8-7). Results. At baseline, spironolactone was commenced in all patients. The dose was 33.3 +/- 13.7 and 29.0 +/- 11.7 mg/day at 1 year and 3 years, respectively. A total of 73% of the patients received <= 37.5 mg/day. Introduction of spironolactone enabled the reduction of other antihypertensive medications (from 2.6 +/- 1.2 to 1.5 +/- 1.0 at 1 year). At 1 year, systolic and diastolic blood pressure decreased (149.3 +/- 14.1 to 126.2 +/- 12.0 mmHg, P < 0.001, and 88.2 +/- 9.8 to 78.3 +/- 7.1 mmHg, P < 0.001, respectively). At baseline, LVH was present in 39 of the 48 (81%) patients, and concentric remodelling, i.e. increased relative wall thickness (RWT) with a normal left ventricular mass index (LVMI), in 36 (75%). At 1 year, LVMI decreased in 44 of the 48 (92%) patients (142.9 +/- 25.4 versus 117.7 +/- 20.4 g/m(2), P < 0.001). LVH normalized in 16 of the 39 (41%) patients. RWT normalized in 36% of the patients. The changes in blood pressure and LVMI did not correlate. At 3 years, LVH decreased further and normalized in 57% of the patients. Conclusions. In patients with PA/low-renin hypertension, long-term regression of LVH may be achieved with low-dose MRB.