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Implications of the primary prevention trials against coronary heart disease
1Section of Preventive Medicine and Epidemiology, Boston University, Massachusetts.
Insights
Antihypertensive drugs offer limited benefits for coronary heart disease outcomes, with some vascular events reduced. Lifestyle changes like smoking cessation and lipid control may be more effective for preventing coronary issues in hypertensive individuals.
Area of Science:
- Cardiology
- Pharmacology
- Public Health
Background:
- Hypertension significantly contributes to mortality, primarily through coronary heart disease.
- While drug therapy slows hypertension progression, its impact on coronary outcomes and overall mortality remains equivocal.
- Current antihypertensive therapies have shown only a small, statistically insignificant reduction in coronary heart disease morbidity and mortality.
Purpose of the Study:
- To evaluate the effectiveness of antihypertensive drug therapy in reducing coronary heart disease events.
- To explore reasons for the limited benefits of current therapies on coronary outcomes.
- To compare the efficacy of beta-blockers with other antihypertensive drugs in managing coronary heart disease.
Main Methods:
- Review of recent large clinical trials comparing different antihypertensive drug classes.
- Analysis of outcomes related to coronary heart disease morbidity and mortality.
- Exploration of potential factors influencing therapeutic outcomes, including trial duration, sample size, and impact on cardiovascular risk factors.
Main Results:
- Antihypertensive therapy has primarily reduced vascular events like renal failure, stroke, and cardiac failure.
- Recent trials comparing beta-blockers to other agents have not met expectations for coronary outcome benefits.
- Two trials suggest potential efficacy of beta-blockers in male non-smokers for coronary heart disease.
Conclusions:
- The benefits of antihypertensive therapy for coronary heart disease are limited and possibly offset by adverse effects on lipids and glucose metabolism.
- Factors such as trial duration, sample size, and attention to the overall cardiovascular risk profile may explain therapeutic failures.
- Lifestyle modifications, including smoking cessation and serum lipid control, are crucial and potentially more effective than blood pressure control alone in preventing coronary heart disease in hypertensive individuals.
Abstract:
The bulk of the mortality (60%) in hypertension occurs in those with mild to moderate elevations of blood pressure, and the chief hazard is coronary disease. Although progression in the severity of hypertension has been slowed with drug therapy, the benefits for coronary outcome and all-cause mortality have been equivocal. Only a 10% reduction in coronary heart disease morbidity and mortality has been shown, an improvement that is not only small, but is statistically insignificant. Only vascular events such as renal failure, stroke, aortic dissection and cardiac failure have been reduced by antihypertensive therapy. Recent trials comparing beta-blockers with other antihypertensive drugs have failed to show the expected promise based on their effectiveness following a myocardial infarction. However, two large trials suggest that they may be effective against coronary heart disease in male non-smokers. A number of possible reasons for this therapeutic failure to reduce coronary heart disease have been postulated. The trials may have been too short to significantly affect the atherosclerotic progression. Also, sample sizes were too small to detect a sizeable reduction in coronary heart disease events. Furthermore, no attention was paid to improvements in the coronary heart disease risk profile, since drugs currently in use are known to have adverse effects on blood lipids, glucose tolerance and uric acid. It is even possible that a predisposition to sudden death is associated with antihypertensive therapy. The trials suggest that in attempts to prevent coronary heart disease, control of smoking and of serum lipids are particularly important in hypertensive persons and may be more effective than controlling the blood pressure alone.(ABSTRACT TRUNCATED AT 250 WORDS)