Renal and cardiac effects of antihypertensive treatment with ramipril vs metoprolol in autosomal dominant polycystic kidney disease

Background. Hypertension is a common complication in autosomal dominant polycystic kidney disease (ADPKD). This prospective randomized double-blind study was performed to compare the renal and cardiac effects of the ACE inhibitor ramipril and the β-blocker metoprolol as first line therapy in ADPKD patients with hypertension. Methods. Forty-six hypertensive ADPKD patients were randomized to either ramipril (n = 23) or metoprolol (n = 23). Twenty-four hour (24-h) ambulatory blood pressure (BP), glomerular filtration rate (GFR) as calculated by the Cockcroft and Gault formula, urinary albumin excretion (albumin/creatinine ratio), and left ventricular mass index (LVMI) were established at baseline and at yearly intervals. The total follow-up was 3 years. Baseline characteristics were similar in both groups. Results. Mean arterial pressure (MAP) decreased significantly in both the ramipril and the metoprolol group (−8 ± 2 and −6 ± 2 mmHg; both P < 0.01). There was a significant decline in renal function during follow-up which was similar in patients treated with ramipril or metoprolol (−2.5 ± 0.7 vs −2.9 ± 0.8 ml/min/year; P = NS). After the 3 years follow-up, no differences in GFR, LVMI and urinary albumin excretion were observed between the ramipril and the metoprolol group (80.7 ± 10.7 vs 78.0 ± 7.6 ml/min, 102.6 ± 6.8 vs 100.3 ± 5.4 g/m2; and 42.6 ± 12.3 vs 70.3 ± 32.5 mg/g, respectively; all P = NS). A post-hoc analysis evaluating the effects of BP control, revealed that LVMI increased in patients with standard BP control while it remained stable in patients with rigorous BP control with a significant difference in LVMI between the groups after 3 years of follow-up (110.5 ± 6.3 vs 90.9 ± 4.7 g/m2; P = 0.017). Also, by the end of the study albuminuria was lower in patients with rigorous vs standard BP control (23.5 ± 6.7 vs 94.8 ± 35.4 mg/g; P = 0.05). Conclusions. In our study population of hypertensive ADPKD patients, no differences in renal function, urinary albumin excretion and LVMI were detected between those treated with ramipril or metoprolol, respectively, during a 3 years follow-up. Rigorous BP control prevented an increase in LVMI and reduced urinary albumin excretion, suggesting a crucial role of BP control for slowing progression of cardiac and renal organ damage in ADPKD.