Chlorthalidone for Hypertension in Advanced Chronic Kidney Disease.

BACKGROUND: Little evidence has been available to support the use of thiazide diuretics to treat hypertension in patients with advanced chronic kidney disease. METHODS: We randomly assigned patients with stage 4 chronic kidney disease and poorly controlled hypertension, as confirmed by 24-hour ambulatory blood-pressure monitoring, in a 1:1 ratio to receive chlorthalidone at an initial dose of 12.5 mg per day, with increases every 4 weeks if needed to a maximum dose of 50 mg per day, or placebo; randomization was stratified according to previous use of loop diuretics. The primary outcome was the change in 24-hour ambulatory systolic blood pressure from baseline to 12 weeks. Secondary outcomes were the change from baseline to 12 weeks in the urinary albumin-to-creatinine ratio, N-terminal pro-B-type natriuretic peptide level, plasma renin and aldosterone levels, and total body volume. Safety was also assessed. RESULTS: A total of 160 patients underwent randomization, of whom 121 (76%) had diabetes mellitus and 96 (60%) were receiving loop diuretics. At baseline, the mean (±SD) estimated glomerular filtration rate was 23.2±4.2 ml per minute per 1.73 m2 of body-surface area and the mean number of antihypertensive medications prescribed was 3.4±1.4. At randomization, the mean 24-hour ambulatory systolic blood pressure was 142.6±8.1 mm Hg in the chlorthalidone group and 140.1±8.1 mm Hg in the placebo group and the mean 24-hour ambulatory diastolic blood pressure was 74.6±10.1 mm Hg and 72.8±9.3 mm Hg, respectively. The adjusted change in 24-hour systolic blood pressure from baseline to 12 weeks was -11.0 mm Hg (95% confidence interval [CI], -13.9 to -8.1) in the chlorthalidone group and -0.5 mm Hg (95% CI, -3.5 to 2.5) in the placebo group. The between-group difference was -10.5 mm Hg (95% CI, -14.6 to -6.4) (P<0.001). The percent change in the urinary albumin-to-creatinine ratio from baseline to 12 weeks was lower in the chlorthalidone group than in the placebo group by 50 percentage points (95% CI, 37 to 60). Hypokalemia, reversible increases in serum creatinine level, hyperglycemia, dizziness, and hyperuricemia occurred more frequently in the chlorthalidone group than in the placebo group. CONCLUSIONS: Among patients with advanced chronic kidney disease and poorly controlled hypertension, chlorthalidone therapy improved blood-pressure control at 12 weeks as compared with placebo. (Funded by the National Heart, Lung, and Blood Institute and the Indiana Institute of Medical Research; CLICK ClinicalTrials.gov number, NCT02841280.).

Design and Baseline Characteristics of the Chlorthalidone in Chronic Kidney Disease (CLICK) Trial.

BACKGROUND: Hypertension often accompanies chronic kidney disease (CKD), and diuretics are widely prescribed to reduce blood pressure (BP). Chlorthalidone (CTD) is a thiazide-like diuretic and an effective antihypertensive drug, yet little data exist to support its use in treating hypertension in individuals with advanced CKD. METHODS: Chlorthalidone in Chronic Kidney Disease (CLICK) is a phase II, single-institution, multicenter, double-blind randomized control trial to test the hypothesis that CTD improves BP, through reduction of extracellular fluid volume, and results in target organ protection in patients with stage 4 CKD and poorly controlled hypertension. After a single-blind placebo run-in for 2 weeks and confirmation of hypertension by 24-h ambulatory blood pressure (ABP), patients are randomized to either placebo or CTD 12.5 mg once daily (QD) followed by dose escalation. Randomization is stratified by prior loop diuretic use, and the double-blind phase lasts 12 weeks. With a total of 160 patients, the study will have ≥80% power to detect a 6 mm Hg difference in systolic 24-h ABP between the 2 treatment groups. RESULTS: Between June 2016 and October 2019, 131 patients have been randomized. The baseline characteristics are as follows: average age 65.8 years, 79% men, 36% Black, 79% with diabetes, mean eGFR 23.2 mL/min/1.73 m2, median urine albumin/creatinine ratio 923 mg/g, average number of BP medications 3.4, 60% on loop diuretics, and 24-h ABP averaged 141.7/73.8 mm Hg. CONCLUSION: Among patients with stage 4 CKD and uncontrolled hypertension, CLICK should answer the question whether CTD is safe and effective.