Thiazide Diuretics Proven to Help Prevent Heart Failure

Thiazide diuretics were first developed by Merck in the 1950s, and chlorothiazide marketed as Diuril became the first FDA-approved drug of this class in 1958. Following additional FDA approvals, the class expanded to include thiazide-type diuretics, like hydrochlorothiazide, as well as thiazide-like diuretics, like indapamide and chlorthalidone.

Use of thiazide diuretics to lower blood pressure and decrease edema is widespread. For the approximately 5.3 million Americans with heart failure, these drugs are often used with lifestyle modification and a set of other medications to reduce morbidity and mortality. Of note, thiazide diuretics are the least expensive antihypertensive drugs available in most countries.

A meta-analysis published in the April 2015 issue of the American Journal of Hypertension indicates the use of thiazide diuretics in hypertensive patients reduces the risk of cardiac events and can be considered cardioprotective. The researchers included 19 randomized clinical trials with a total of 112,113 patients—half in treatment arms and half in control arms—that examined thiazide diuretic use and health outcomes.

They found patients treated with thiazide diuretics had an incidence ratio of 34.3 cardiac events per 1,000 patient-years, compared with 37.8 cardiac events per 1,000 patient-years in the control arms—representing a 24% reduction.

Additionally, heart failure risk was 38% lower in thiazide diuretic-treated patients than control subjects. However, rates of stroke and coronary heart disease were similar in both treatment and control arms.

Beneficial effects were more likely to be seen in patients taking thiazide-like diuretics, especially those with heart failure, though the researchers observed a modest trend toward cardioprotection with thiazide-type diuretics. They interpreted this to mean thiazide-like diuretics offer greater cardioprotection.

The authors indicated clinicians might consider using thiazide-like diuretics rather than thiazide-type diuretics to increase cardiovascular benefits in hypertensive patients. They also note the use of this drug class is a cost-effective approach clearly associated with good clinical outcomes.