Abstract 327: The Choice of Diuretic is Important in the Treatment of Resistant Hypertension
Background: Diuretic therapy is a critical part of the antihypertensive regimen in patients with resistant HTN; however, the ideal diuretic regimen has not been defined. We hypothesized that BP response is dependent on diuretic type. In the current study, BP response with hydrochlorothiazide (HCTZ), chlorthalidone, and loop diuretics was compared for treatment of resistant HTN.
Methods: Data from clinic visits of adults who were referred for resistant HTN to the HTN Clinic at the University of Alabama at Birmingham between January 2008 and May 2013 were analyzed. Changes in office BP by diuretic type were assessed using a mixed linear model to account for multiple clinic visits with covariate adjustment. Aldosterone status and dietary sodium/potassium were tested for associations with response to diuretic therapy in a subset of patients with complete 24 hour urine collections (n = 131).
Results: The study population consisted of 342 patients with 963 clinic visits; 153 out of 342 patients were Black and 202 were women. The median BP on presentation was 152/83 mm Hg while taking 4 (median) classes of antihypertensive medications. Over the course of a median of 3 visits the presence of a diuretic was associated with a lowering in office systolic BP (p = 0.001) after adjusting for age, race, number of medication classes, time between visits, spironolactone use, and CKD stage. However, analyzed by diuretic type, chlorthalidone significantly reduced office BP (p < 0.0001) while HCTZ and loop diuretics did not (p = 0.6 and p = 0.9, respectively) after adjustment for covariates. In the adjusted model, an increase in chlorthalidone dose by 12.5mg was associated with a 5.0 mm Hg reduction in office systolic BP. The BP response to chlorthalidone did not vary by race (p = 0.3), dietary sodium-to-potassium intake (p= 0.3), or aldosterone status (p = 0.4), yet was reduced by increasing CKD stage (p = 0.01).
Conclusions: Chlorthalidone was shown to affect BP response in resistant HTN with significant reductions in BP, while HCTZ and loop diuretics were not. The response to chlorthalidone was not explained by race, dietary sodium-to-potassium ratio, or aldosterone status.
Author Disclosures: E. Judd: None. C.M. Colon: None. G. Cutter: None. D.A. Calhoun: None.
- © 2014 by American Heart Association, Inc.