What is the role of angiotensin-receptor blockade in cardiovascular protection?

Angiotensin receptor blockers: role in hypertension management, cardiovascular risk reduction, and nephropathy

BACKGROUND

The renin-angiotensin system (RAS) plays a central pathogenic role in the development of hypertension and associated vascular disorders. However, whether the two main classes of agents that blunt RAS activity-angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs)-yield comparable cardioprotective and renoprotective effects in high-risk patients is controversial.

METHOD

An analysis of several controlled clinical trials provides evidence that, in patients with or without heart failure, ARBs provide protective effects and improvements in prognosis compared with those achieved with ACEIs.

RESULTS

This article describes the critical studies that examine the cardioprotective and renoprotective efficacy of ARBs and identifies the populations and doses at which these agents are most effective.

DISCUSSION

In the clinical setting, ARBs may be a valuable alternative to ACEI therapy. Because of their tolerability profile, ARBs or ARB combination therapy may be an option for patients susceptible to ACEI-related adverse events.

Beneficial Effects of Valsartan in Asymptomatic Individuals With Vascular or Cardiac Abnormalities

OBJECTIVES

We studied the efficacy of valsartan (Val) to slow cardiovascular disease progression in asymptomatic high-risk prehypertensive or hypertensive patients with blood pressure (BP) controlled to <140/90 mm Hg and with evidence for functional or structural alterations in the cardiovascular system.

BACKGROUND

Identifying individuals with early markers for cardiovascular disease raises the possibility for pharmacotherapy to slow progression and delay or prevent future morbid events.

METHODS

Seventy-six subjects with a Rasmussen Disease Score (RDS) of 6 or higher were randomized double-blind to receive placebo (Plac) or Val 160 mg once daily for 6 months followed by 6 months of single-blind Val in both groups. A panel of 10 tests, including large and small artery elasticity, resting and treadmill exercise BP, carotid intimal-media thickness, retinal vascular photography, micro-albuminuria, electrocardiography, echocardiography, and plasma B-type natriuretic peptide, was performed at baseline and after 6 and 12 months of treatment. Each test result was scored as normal (0), borderline (1), or abnormal (2), and the total RDS was calculated by adding all the scores of the individual tests.

RESULTS

Valsartan significantly reduced the RDS after 6 months versus Plac (p < 0.03) and at 12 months (either 12 or 6 months of Val, p < 0.0001). The major contribution in risk score reduction was due to an increase in small artery elasticity and a decrease in BP, and after 12 months there was a reduction in left ventricular mass index (p < 0.03).

CONCLUSIONS

Valsartan can slow progression and/or reverse early cardiovascular disease in asymptomatic high-risk patients with prehypertension or BP controlled to <140/90 mm Hg.