Objectives: We report the results of an echocardiographic substudy carried out in a trial comparing the effects of two different treatment strategies - mineralocorticoid receptor blockade (MRB) and dual renin-angiotensin system blockade (RASB) - in patients with resistant hypertension. Both strategies reduce left ventricular mass index (LVMI), but they have not been compared in patients with resistant hypertension.
Methods: After 4-week treatment with 300 mg irbesartan + 12.5 mg hydrochorothiazide + 5 mg amlodipine, 86 patients with resistant hypertension were randomized to the add-on 25 mg spironolactone (MRB group, n = 46) or 5 mg ramipril (RASB group, n = 40) groups for 12 weeks. Treatment intensity was increased at week 4, 8 or 10 if home blood pressure (BP) was equal to or above 135/85 mmHg, by sequentially adding 20-40 mg furosemide and 5 mg amiloride (MRB group), or 10 mg ramipril and 5-10 mg bisoprolol (RASB group). Transthoracic echography was performed at baseline and week 12.
Results: Daytime ambulatory BP decreased by 19 ± 12/11 ± 8 mmHg in the MRB group and by 8 ± 13/7 ± 7 mmHg in the RASB group (P = 0.0003/0.03). LVMI decreased by 8.2 ± 18.9 g/m in the MRB group, whereas it increased by 1.8 ± 19.1 g/m in the RASB group (P = 0.03). The decreases in posterior wall thickness, left ventricular (LV) end-systolic diameter, E/e' ratio and left atrial area were significantly greater with MRB than with RASB. The difference between groups remained significant after adjustment for the decrease in ambulatory BP.
Conclusion: In patients with resistant hypertension, MRB-based treatment decreased both BP and LVMI more efficiently than a strategy based on dual RASB.