Related Experiment Videos
Vascular effects of systemic hypertension
1Whitaker Cardiovascular Institute, Boston University School of Medicine, Massachusetts 02118.
Insights
Hypertension significantly increases cardiovascular risks like stroke and coronary artery disease (CAD). While lowering blood pressure reduces stroke risk, its effect on CAD is less pronounced, potentially due to factors beyond blood pressure control.
Area of Science:
- Cardiology
- Nephrology
- Vascular Biology
Background:
- Hypertension is a primary risk factor for numerous cardiovascular diseases, including coronary artery disease (CAD), stroke, and heart failure.
- It also significantly promotes atherosclerosis and is a leading cause of renal failure, particularly in Black males.
- Observational data show a direct correlation between elevated blood pressure and increased risk for CAD and stroke.
Purpose of the Study:
- To review the impact of hypertension on cardiovascular and renal health.
- To analyze the effectiveness of hypertension reduction on stroke and CAD incidence.
- To explore potential mechanisms behind the modest effects of antihypertensive drugs on CAD and renal function.
Main Methods:
- Review of observational studies and clinical trials on hypertension and cardiovascular outcomes.
- Analysis of factors influencing the relationship between blood pressure and disease risk.
- Examination of the direct vascular effects of antihypertensive medications.
Main Results:
- Hypertension reduction effectively lowers stroke incidence but has a lesser impact on CAD incidence than predicted.
- Factors like unaddressed atherosclerosis, metabolic side effects of drugs, and inadequate myocardial perfusion may limit CAD benefits.
- Hypertension control does not always prevent renal function decline, with increased glomerular pressure implicated in hypertensive and diabetic kidney disease.
Conclusions:
- While hypertension is a major cardiovascular and renal risk factor, its management requires a comprehensive approach beyond just blood pressure reduction.
- Antihypertensive agents may possess direct vascular protective effects independent of their blood pressure-lowering action.
- Further research is needed to determine the clinical significance of these direct vascular effects of medications like beta-blockers, calcium antagonists, and ACE inhibitors.
Abstract:
Hypertension is a major risk factor for cardiovascular diseases, including coronary artery disease (CAD), stroke, left ventricular hypertrophy (LVH), congestive heart failure, peripheral vascular disease, renal failure, and aortic aneurysms. It is also a potent promoter of atherosclerosis. Observational studies have shown a linear relationship between a wide range of blood pressures and the risk for CAD and stroke. Clinical trials have indicated that hypertension reduction leads to the predicted reduction in stroke incidence, but that CAD incidence is affected to a lesser extent than predicted. The modest effect of traditional antihypertensive drugs on CAD may be due to several factors, including failure to reverse well-established coronary atherosclerosis, particularly if multiple risk factors are not reduced as well. Metabolic side effects of antihypertensive drugs or excessive lowering of blood pressure leading to inadequate myocardial perfusion, especially in patients with increased left ventricular (LV) mass, also may play important roles. Hypertension is a major cause of renal failure, particularly in black males, but control of the hypertension does not necessarily prevent deterioration of renal function. Increased glomerular pressure is thought to play a causative role in the development of renal failure in hypertensive and diabetic patients. Antihypertensive drugs may have a direct effect on the arterial wall, which may be independent of their antihypertensive action. Beta-adrenergic blockers, calcium antagonists, and angiotensin-converting enzyme (ACE) inhibitors inhibit the development of vascular lesions in response to hypercholesterolemia or to iatrogenic balloon injury, but the clinical importance of these observations remains to be determined.