4 September 2009
Nishizaka MK, Zaman MA, and Calhoun DA. Efficacy of Low-Dose Spironolactone in Subjects with Resistant Hypertension. American Journal of Hypertension 2003; 16: 925-930.
Objective: In patients with resistant hypertension, does addition of aldosterone inhibition lead to decreased systolic and diastolic blood pressure?
-Inclusion criteria: 1) Prior enrollment in a study of prevalence of primary aldosteronism (PA) in subjects with resistant hypertension. 2) Uncontrolled HTN at 2+ clinic visits despite 3+ agents including a diuretic and either ACE or ARB. 3) Secondary HTN previously ruled out (other than PA). Southern US city, university center.
-All subjects were tested for presence of PA, defined as suppressed plasma renin activity (<1.0 ng/mL/h) in setting of 24-hour urine collection for aldosterone being high (>12 μg/24 h) and 24-hour urine collection for sodium being high (>200 mEq/24 h).
-Randomization: None. Divided into presence or absence of primary aldosteronism.
-Intervention: Low-dose spironolactone 12.5 to 25 mg daily was added, with uptitration to 50 mg daily if BP uncontrolled. Reassessment for BP was done at 6 weeks, 3 months, and 6 months. Repeat lytes done at each f/u and 2 weeks post-uptitration as indicated.
-Primary outcome measure: Systolic and diastolic blood pressure.
-Statistical analysis: student’s t test, one-way ANOVA, linear regression.
-n=76; 34 with primary aldosteronism.
-Mean systolic blood pressure decrease was 25 +/- 20 mmHg. Mean diastolic blood pressure decrease was 12 +/- 12 mmHg.