A cardiologist's perspective on evolving concepts in the management of congestive heart failure

Clinical characteristics of vesnarinone

Congestive heart failure is a common condition with a poor prognosis. Its high rates of morbidity and mortality produce a huge societal burden. Current pharmacological treatment approaches are based on angiotensin-converting enzyme inhibitors, diuretics and digoxin, but up to 5% of patients may have refractory disease with persistent symptoms at rest. Such patients with advanced-stage disease may be candidates for treatment with the novel agent vesnarinone, a mixed phosphodiesterase inhibitor and ion-channel modifier that has modest, dose-dependent, positive inotropic activity, but minimal negative chronotropic activity. Vesnarinone improves ventricular performance most in patients with the worst degree of heart failure. However, before the initiation of vesnarinone therapy, risk-benefit profiles in individual patients should be considered, because in two large-scale studies [i.e. of the high dosage used in the Vesnarinone Study Group Trial (VSGT), and of both dosages used in the Vesnarinone Trial (VEST)] a dose-dependent increase in mortality was identified for vesnarinone 30-120 mg/day. The two studies also found significant vesnarinone-induced, short-term improvements in quality of life (QOL) in patients with refractory end-stage heart failure. Such patients are the most willing to trade-off a slightly increased risk of mortality for improved QOL. It is thus in these patients with refractory end-stage heart failure that vesnarinone may ultimately establish an important treatment role. However, detailed further investigation of the overall place of vesnarinone in heart failure management, with particular reference to the clinical potential of vesnarinone plus beta-blocker combination therapy, for example, is certainly warranted.

Determinants of angiotensin-converting enzyme inhibitor prescription in severe heart failure with left ventricular systolic dysfunction: the EPICAL study

BACKGROUND

Angiotensin-converting enzyme (ACE) inhibitors have been demonstrated to reduce morbidity and mortality rates in patients with heart failure with left ventricular systolic dysfunction. Nevertheless, these drugs are underutilized in current practice and prescribed at doses below those usually recommended. The aim of this work was to identify the social, demographic, laboratory, clinical, and therapeutic factors associated with nonprescription of ACE inhibitors and/or their prescription at doses below those recommended in the treatment of severe long-term congestive heart failure (CHF).

METHODS AND RESULTS

An epidemiologic observational study, EPICAL (EPidémiologie de l'Insuffisance Cardiaque Avancée en Lorraine), studied 417 patients with severe CHF surviving after the index hospitalization. Multivariate logistic regression determined the factors associated with ACE inhibitor nonprescription and with their prescription at lower-than-recommended doses. ACE inhibitors were taken by 75% of the patients but 38% took lower-than-recommended doses. Factors shown to be associated with nonprescription included patients >65 years of age with renal impairment (odds ratio 19.5, confidence interval [CI] 7.9-48.0), nonsinus cardiac rhythm (odds ratio 2.0, CI 1.2-3.2), and prescription of potassium-sparing diuretics (odds ratio 2.4, CI 1. 2-4.7). Renal impairment was the single most important factor associated with prescription of lower-than-recommended doses, particularly in elderly patients.

CONCLUSIONS

Our results underline the need for optimal and better use of ACE inhibitor therapy. CHF treatment guidelines must be more uniformly applied by all physicians caring for patients with heart failure.

Effect of increasing gastric pH with famotidine on the absorption and oral pharmacokinetics of the inotropic agent vesnarinone

The effect of famotidine, an H2 receptor blocker, on the oral absorption and pharmacokinetics of the novel agent vesnarinone was investigated after oral administration of 60 mg vesnarinone with and without pretreatment with intravenous famotidine. The single-blind, randomized, two-way crossover study was conducted in 12 volunteers, with a washout period of 7 days between the two treatments. A pH monitor was used to ensure that gastric pH of the subjects was < or = 3 in the absence of and > or = 5 in the presence of famotidine. A significant decrease in maximum concentration (Cmax) and increase in time to Cmax (tmax) was observed for vesnarinone during treatment with famotidine, whereas area under the concentration-time curve (AUC) was similar for both treatments. The physicochemical properties of the drug support the above observations. Therefore, therapies that increase gastric pH will affect the rate but not the extent of absorption of vesnarinone or the safety or efficacy profile of vesnarinone.