Chlorthalidone vs Hydrochlorothiazide for Hypertension Treatment After Myocardial Infarction or Stroke: A Secondary...

Area of Science:

• Cardiovascular Medicine
• Pharmacology
• Clinical Trials

Background:

• Patients with a history of myocardial infarction (MI) or stroke face an elevated risk of recurrent cardiovascular (CV) events.
• Hydrochlorothiazide (HCTZ) is a commonly prescribed diuretic for hypertension, but its comparative effectiveness against other diuretics in high-risk populations is of interest.

Purpose of the Study:

• To investigate the association of chlorthalidone (CTD) versus HCTZ with cardiovascular outcomes and noncancer deaths.
• To specifically evaluate these associations in patients with and without a prior history of MI or stroke.

Main Methods:

• A secondary analysis of the Diuretic Comparison Project (DCP), a pragmatic randomized clinical trial.
• Included patients aged 65+ with hypertension, randomized to continue HCTZ or switch to CTD at comparable doses.
• Evaluated treatment effects in subgroups based on the presence or absence of prior MI or stroke.

Main Results:

• A significant interaction was observed between treatment group and history of MI or stroke (P=.01).
• Patients with prior MI or stroke randomized to CTD showed a lower risk of primary composite CV outcomes (HR, 0.73; P=.01).
• In contrast, participants without prior MI or stroke had a slightly higher risk of primary outcomes with CTD (HR, 1.12; P=.054).

Conclusions:

• Chlorthalidone (CTD) may be associated with reduced major adverse cardiovascular events and noncancer deaths in patients with a history of MI or stroke compared to HCTZ.
• The findings suggest a potential differential benefit of CTD over HCTZ in high-risk cardiovascular patient populations.