Comparison of cardiovascular outcomes between chlorthalidone and hydrochlorothiazide in hypertensive patients

Background Chlorthalidone and hydrochlorothiazide are widely used thiazide diuretics for hypertension management. This study aimed to evaluate and compare the cardiovascular outcomes of patients treated with chlorthalidone versus hydrochlorothiazide. Methods This multicenter retrospective cohort study utilized data from our medical center, derived from electronic health records. A total of 14,257 hypertensive patients treated with either chlorthalidone (n = 1,920) or hydrochlorothiazide (n = 12,337) were identified. Patients were matched 1:1 using propensity scores, resulting in 1,606 patients in each treatment group. Demographic and clinical characteristics, incidence of major adverse cardiovascular events (MACE), and safety profiles were analyzed. Results Baseline characteristics after propensity score matching were well balanced between the two groups. The average age was 61.8 ± 14.6 years for chlorthalidone users, with 59.3% being male. The 3-year MACE occurred in 1.2% of the chlorthalidone group compared with 1.4% of the hydrochlorothiazide group (hazard ratio 0.91, p = 0.77). For secondary outcomes, cardiovascular mortality was 0.2% in both groups (p = 0.92). Myocardial infarction occurred in 0.3% of chlorthalidone users and 0.4% of hydrochlorothiazide users (p = 0.65). The incidence of hypokalemia was 19.2% in the chlorthalidone group versus 16.7% in the hydrochlorothiazide group (p = 0.07). Conclusions In hypertensive patients, chlorthalidone and hydrochlorothiazide showed comparable cardiovascular outcomes and safety profiles.