New opportunities in cardiovascular patient management: a survey of clinical data on the combination of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers

Detecting low-abundance vasoactive peptides in plasma: progress toward absolute quantitation using nano liquid chromatography-mass spectrometry

Profiling changes in the concentration of functionally related peptide hormones is critical to understanding the etiology of many diseases and therapies. We present novel data using nano liquid chromatography-mass spectrometry (LC-MS) to simultaneously measure a select group of vasoactive peptides (angiotensin, bradykinin, and related hormones) in 50-microl plasma samples, enabling repeated sampling in rodent models. By chromatographically resolving target peptides and using multiple reaction monitoring to enhance MS sensitivity, linear responses down to 10(-17) mol were achieved. Purification of plasma peptides by either methanol precipitation or off-line high-performance liquid chromatography (HPLC) fractionation enabled the detection of endogenous peptides and revealed approaches for enhancing recovery. As proof of principle, seven vasoactive peptides were profiled before, during, and after acute angiotensin-converting enzyme (ACE) inhibition in an anesthetized rat. Of note was an apparent 10-fold increase in vasodilatory bradykinin that reversed after drug infusion but relatively minor changes in angiotensin II levels. Targeted MS analysis used to profile functionally related peptides or other analytes will greatly enhance our ability to define the sequence of events regulating complex and dynamic physiological processes.

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.

On target to dual block RAS?

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are thought to possess cardioprotective, cerebroprotective, and nephroprotective properties. Both classes of agents can prevent or reverse endothelial dysfunction and atherosclerosis, thereby potentially reducing the risk of cardiovascular events. Such a reduction has been shown with angiotensin-converting enzyme inhibitors in patients with coronary artery disease, but no such data are scarce with angiotensin receptor blockers (Valsartan in Acute Myocardial Infarction study). Both angiotensin-converting enzyme inhibitors and angiotensin receptor blockers have been shown to reduce damage in target organs, such as the heart and kidney, and to decrease cardiovascular mortality and morbidity in patients with congestive heart failure. These drugs (especially angiotensin receptor blockers) may successfully prevent atrial fibrillation and play a protective role in metabolic syndrome. In some clinical settings, combined therapy angiotensin-converting enzyme inhibitors with angiotensin receptor blocker (double blockade of the renin-angiotensin- aldosterone system) may appear the most effective.

Evaluation of recent fixed-dose combination therapies in the management of hypertension

PURPOSE OF REVIEW

Control of hypertension remains sub-optimal with only half of patients achieving adequate control. The Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure guidelines recommend initial use of two antihypertensive agents in patients with stage 2 hypertension. This review discusses the drug combinations that have additive effects and those that do not provide additional benefit while increasing the adverse events.

RECENT FINDINGS

Results from late-breaking trials have shown that combinations of a calcium channel blocker and angiotensin-converting enzyme inhibitor are superior to a diuretic with an angiotensin-converting enzyme inhibitor for reducing cardiovascular events. Additionally, in patients with vascular disease with relatively 'controlled' blood pressure at baseline, the combination of an angiotensin-converting enzyme inhibitor and angiotensin receptor blocker did not reduce cardiovascular endpoints compared with either monotherapy and modestly increased the incidence of adverse effects.

SUMMARY

Combination therapy of antihypertensive agents (e.g. angiotensin-converting enzyme inhibitor/calcium channel blocker, angiotensin-converting enzyme inhibitor/diuretics, and angiotensin receptor blocker/diuretics) as initial therapy in stage 2 hypertension can lead to markedly improved blood pressure control in patients compared with monotherapeutic regimens.