Antihypertensive Drug Therapies and the Risk of Ischemic Stroke - Antihypertensive Drug Therapies and the Risk of Ischemic Stroke

Description:

Antihypertensive Drug Therapies and the Risk of Ischemic Stroke

Hypothesis:

There is accumulating evidence that when treating hypertension, drug class may influence event rates independent of blood pressure targets. This study sought to determine the association between stroke and use of antihypertensive drugs.

Study Design

Study Design:

Patients Enrolled: 380

Drug/Procedures Used:

This population case-controlled study used data from a staff model HMO in Western Washington to compare antihypertensive therapies pre stroke in 380 patients hospitalized with a first ischemic stroke with 2790 controls. Two hundred and thirty-one cases and 715 controls had been excluded because of congestive heart failure, drug non-compliance or drug inconsistency. Among the covariables assessed were smoking, medical history, history of cardiovascular disease (CVD) and individual combinations of antihypertensive drug classes, including diuretics (thiazide and non-thiazide), beta-blockers, angiotensin converting enzyme inhibitors and calcium-channel blockers.

Principal Findings:

Compared to the controls, the patients were older (70 vs. 66 years), more were women (54% vs. 33%) and systolic pressure was higher, as was sedentary life style, duration of treatment, number of antihypertensive drugs, and percentage with diabetes (31 vs. 11%) and CVD (60 vs. 38%). Among those without CVD, compared to those regimens that used a thiazide, the relative risk of an ischemic stroke was 2.4 in single drug and 1.4 in two-drug regimens, an 85% increase overall. The association persisted after adjustment for confounding factors including age and blood pressure and clinical subsets but was less pronounced in those with CVD.

Conclusions: Antihypertensive drug regimens that did not include a thiazide diuretic were associated with an increased risk of ischemic stroke compared to regimens that did include a thiazide. These results support the use of thiazide diuretics as first-line antihypertensive agents, particularly in the elderly.

Interpretation:

The findings from randomized controlled trials (RCT) of antihypertensive agents are not uniform, but several are in agreement with this case-controlled study. It is heartening that in older non-CVD patients, the cheapest antihypertensive drug for preventing strokes may also be very effective. Because the benefit of each agent in the prevention of coronary events and cardiovascular and total mortality in men and women of all ages cannot be gleaned from this study, the results should be interpreted with caution.

References:

1. Klungel OH, Heckbert SR, Longstreth WT, et al. Arch Int Med 2001;161:37-43.

Clinical Topics: Heart Failure and Cardiomyopathies, Prevention, Acute Heart Failure, Hypertension, Smoking

Keywords: Washington, Stroke, Life Style, Diuretics, Blood Pressure, Calcium Channel Blockers, Smoking, Thiazides, Heart Failure, Health Maintenance Organizations, Hypertension, Diabetes Mellitus, Sodium Chloride Symporter Inhibitors


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