Effect of Spironolactone in Resistant Arterial Hypertension: A Randomized, Double-Blind, Placebo-Controlled Trial (ASPIRANT-EXT)

This study was designed to assess the effect of the addition of low-dose spironolactone on blood pressure (BP) in patients with resistant arterial hypertension. Patients with office systolic blood pressure (SBP) >140 mm Hg or diastolic blood pressure (DBP) >90 mm Hg despite treatment with at least 3 antihypertensive drugs, including a diuretic, were enrolled in this double-blind, placebo-controlled, multicentre trial. One hundred sixty-one patients in outpatient internal medicine departments of 6 hospitals in the Czech Republic were randomly assigned to receive 25 mg of spironolactone (N = 81) or a placebo (N = 80) once daily as an add-on to their antihypertensive medication, using simple randomization. This study was registered with ClinicalTrials.gov, number NCT00524615. Analyses were done with 150 patients who finished the follow-up (74 in the spironolactone and 76 in the placebo group). At 8 weeks, BP values were decreased more by spironolactone, with differences in mean fall of SBP of −9.8, −13.0, −10.5, and −9.9 mm Hg (P < 0.001 for all) in daytime, nighttime, and 24-hour ambulatory BP monitoring and in the office. The respective DBP differences were −3.2, −6.4, −3.5, and −3.0 mm Hg (P = 0.013, P < 0.001, P = 0.005, and P = 0.003). Adverse events in both groups were comparable. The office SBP goal <140 mm Hg at 8 weeks was reached in 73% of patients using spironolactone and 41% using placebo (P = 0.001). Spironolactone in patients with resistant arterial hypertension leads to a significant decrease of both SBP and DBP and markedly improves BP control.