Introduction: Resistant hypertension (RH) is defined as a blood pressure (BP) reading that remains above goal despite concurrent use of three optimally dosed antihypertensives of different classes, including a diuretic. Spironolactone, a mineralocorticoid receptor antagonist, has shown significant benefit in reduction of BP in recent trials and is used empirically as an add-on therapy for RH. The researchers’ objective is to evaluate the BP-lowering efficacy of spironolactone in patients with resistant hypertension. Methods: A meta-analysis was performed on randomized controlled trials (RCTs) comparing office or home BP reduction using spironolactone with placebo or an alternative drug regimen on top of standard-triple drug therapy among patients with RH. The study was conducted in reference to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Results: Five RCTs were included comprising a total of 662 patients. Three of these studies were found to have low risk of bias while two had unclear risk of bias. Compared to placebo, the addition of spironolactone significantly decreased office systolic BP (weighted mean difference [WMD]= -16.33, 95% confidence interval [CI]=-24.68 to -7.97, P=0.0001) and office diastolic BP (WMD=-6.12, 95% CI= -9.35 to -2.89, P=0.0002). Compared to an alternative drug regimen, additional spironolactone resulted in a significantly greater reduction in office systolic BP (WMD=-4.58mmHg, 95% CI=-7.19, -1.97, P= 0.0006) and home systolic BP (WMD= -4.33, 95% CI= 5.55, -3.12, P< 0.00001); while the addition of spironolactone had no significant difference compared to an alternative drug regimen in reducing office diastolic BP (WMD=-3.35, 95% CI=-12.08 to +5.38, P=0.45) and home diastolic BP (WMD= 0.00, 95 % CI=-0.73 to 0.73, P=1.0). Conclusion Spironolactone, when added to triple-drug anti-hypertensive therapy, showed significant reduction of systolic office and home BP. It should be considered as the add-on medication of choice for BP reduction in patients with RH.
Antihypertensive Agents ; Spironolactone ; Blood Pressure