Related Experiment Videos
Diuretic therapy for hypertension and the risk of primary cardiac arrest
D S Siscovick1, T E Raghunathan, B M Psaty
1Department of Medicine, University of Washington, Seattle.
Insights
Thiazide diuretic dosage and potassium-sparing drug use impact cardiac arrest risk in hypertension patients. Moderate to high thiazide doses increase risk, while adding potassium-sparing drugs may reduce it.
Area of Science:
- Cardiology
- Pharmacology
- Public Health
Background:
- High-dose thiazide diuretics for hypertension may increase sudden cardiac death risk.
- Low-dose thiazide treatment appears to reduce coronary heart disease risk.
Purpose of the Study:
- To investigate the association between thiazide treatment and primary cardiac arrest.
- To determine how thiazide dosage and potassium-sparing drug use affect cardiac arrest risk.
Main Methods:
- Population-based case-control study of health maintenance organization enrollees.
- 114 hypertensive patients with primary cardiac arrest (cases) and 535 controls.
- Assessed treatment via pharmacy database and reviewed ambulatory care records.
Main Results:
- Combined thiazide and potassium-sparing therapy showed lower cardiac arrest risk (OR, 0.3).
- Moderate (50mg) and high (100mg) thiazide doses increased risk (OR, 1.7 and 3.6).
- Adding potassium-sparing drugs to low-dose thiazides reduced risk (OR, 0.4).
Conclusions:
- Thiazide drug dosage critically influences primary cardiac arrest risk.
- Potassium-sparing drug addition modifies this risk, potentially explaining trial outcome variations.
- Findings highlight the importance of individualized antihypertensive therapy regimens.
Background:
The results of trials of the primary prevention of coronary heart disease have suggested that treating hypertension with high doses of thiazide diuretic drugs might increase the risk of sudden death from cardiac causes. In contrast, treatment with low doses of thiazide reduces the risk of coronary heart disease.
Methods:
To examine the association between thiazide treatment for hypertension and the occurrence of primary cardiac arrest, we conducted a population-based case-control study among enrollees of a health maintenance organization. The case patients were 114 persons with hypertension who had a primary cardiac arrest from 1977 through 1990. The control patients were a stratified random sample of 535 persons with hypertension. The patients' treatment was assessed with the use of a computerized pharmacy data base. Records of their ambulatory care were reviewed to determine other clinical characteristics.
Results:
The risk of primary cardiac arrest among patients receiving combined thiazide and potassium-sparing diuretic therapy was lower than that among patients treated with a thiazide without potassium-sparing therapy (odds ratio, 0.3; 95 percent confidence interval, 0.1 to 0.7). As compared with low-dose thiazide therapy (25 mg daily), moderate-dose therapy (50 mg daily) was associated with a moderate increase in risk (odds ratio, 1.7; 95 percent confidence interval, 0.7 to 4.5), and high-dose therapy (100 mg daily) was associated with a larger increase in risk (odds ratio, 3.6; 95 percent confidence interval, 1.2 to 10.8) (P value for trend, 0.02). The addition of a potassium-sparing drug to low-dose thiazide therapy was associated with a reduced risk of cardiac arrest (odds ratio, 0.4; 95 percent confidence interval, 0.1 to 1.5).
Conclusions:
Both the dose of thiazide drugs and the addition of potassium-sparing drugs influence the risk of primary cardiac arrest. These results may explain the differences in the effect of antihypertensive therapy on mortality from coronary heart disease in previous clinical trials.