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Arterial compliance in hypertension
G M London1, S J Marchais, M E Safar
1Diagnostic Centre, Hôpital Broussais, Paris, France.
Insights
Arterial stiffness, measured by pulse wave velocity (PWV), is reduced in hypertension. Some blood pressure drugs improve arterial compliance, while others do not, indicating effects beyond blood pressure reduction.
Area of Science:
- Cardiovascular Physiology
- Vascular Biology
- Hypertension Research
Background:
- The arterial system performs conduit and cushioning functions, essential for tissue perfusion and cardiac health.
- Reduced arterial lumen diameter causes ischemia, while arterial stiffening increases cardiac workload.
- Arterial compliance, assessed via pulse wave velocity (PWV), is notably lower in hypertensive individuals.
Purpose of the Study:
- To investigate the impact of antihypertensive drugs on arterial compliance.
- To determine if blood pressure-lowering effects correlate with improvements in arterial structure and function.
- To explore the dissociation between blood pressure reduction and vascular changes.
Main Methods:
- Evaluation of arterial compliance using propagative models of the pulse and pulse wave velocity (PWV).
- Comparison of PWV in hypertensive patients versus age-matched controls.
- Assessment of the effects of different antihypertensive drug classes on PWV.
Main Results:
- Hypertensive patients exhibit significantly reduced arterial compliance compared to controls.
- Calcium channel blockers and ACE inhibitors decrease PWV, improving arterial compliance.
- Dihydralazine-like drugs do not modify PWV, despite lowering blood pressure.
Conclusions:
- Antihypertensive drug efficacy extends beyond blood pressure reduction, impacting arterial compliance differently.
- Vascular effects of antihypertensive medications are not solely dependent on their blood pressure-lowering capacity.
- Therapeutic strategies should consider the distinct effects of drugs on arterial structure and function.
Abstract:
The arterial system has two distinct functions: to deliver an adequate supply of blood to body tissues (conduit function) and to smooth the pulsations resulting from intermittent ventricular ejection. A reduction in lumen diameter leads to an abnormal conduit function and has adverse effects (ischaemia) downstream, whilst stiffening of the vessel wall results in abnormal cushioning function and has adverse effects on the heart (increased ventricular stress and myocardial oxygen consumption). Arterial compliance, which may be evaluated using propagative models of the pulse and pulse wave velocity (PWV), is significantly reduced in hypertensive patients compared with age-matched control subjects. The use of antihypertensive drugs is not always associated with differing effects on arterial compliance. Whereas calcium channel blockers and ACE inhibitors decrease PWV for an equivalent fall in blood pressure, dihydralazine-like drugs are unable to modify PWV. This suggests that effects on the structure and function of the heart and blood vessels are dissociated from blood pressure lowering effects.