Effect of angiotensin ii receptor blockade on arterial stiffness: beyond blood pressure reduction

Area of Science:

• Cardiovascular Medicine
• Pharmacology
• Hypertension Research

Background:

• Hypertension is a major risk factor for cardiovascular disease.
• Arterial stiffness contributes to increased blood pressure and cardiovascular events.
• Current antihypertensive medications vary in their effects on arterial properties.

Purpose of the Study:

• To compare the effects of losartan and hydrochlorothiazide on blood pressure and arterial stiffness.
• To investigate whether AT(1) receptor antagonism influences aortic stiffness independently of blood pressure reduction.

Main Methods:

• A 4-week single-blind randomized crossover study involving 11 untreated hypertensive patients.
• Patients received either losartan (50 mg/day) or hydrochlorothiazide (12.5 mg/day) with a 4-week washout period.
• Measurements included brachial blood pressure, arterial wave reflection, pulse pressure amplification, and pulse wave velocity.

Main Results:

• Both losartan and hydrochlorothiazide significantly reduced brachial blood pressure similarly.
• Losartan, but not hydrochlorothiazide, significantly decreased arterial wave reflection and aortic stiffness.
• Losartan also increased pulse pressure amplification and reduced pulse wave velocity.

Conclusions:

• AT(1) receptor antagonism with losartan improves aortic stiffness and reduces arterial wave reflection.
• These vascular benefits of losartan appear to be independent of its blood pressure-lowering effect.
• Losartan may offer advantages over diuretics like hydrochlorothiazide in managing arterial stiffness in hypertensive patients.