Effects of enoximone on quality of life

What is the methodological and reporting quality of health related quality of life in chronic heart failure clinical trials?

BACKGROUND

Although the number of clinical trials assessing health related quality of life (HRQoL) in chronic heart failure (CHF) has increased exponentially over the last decade, little is known about the quality of reporting. The purpose of this review was to assess the methodological and reporting rigor of HRQoL in RCTs of pharmacological therapy in CHF.

METHODS

The electronic data bases, Medline and EMBASE were searched from 1990 to 2009 using the key search terms 'heart failure' combined with 'quality of life', 'pharmacological therapy' and 'randomized controlled trials'. A total of 136 articles were identified and evaluated according to the "Minimum Standard Checklist (MSC) for Evaluating HRQoL Outcomes".

RESULTS

According to the MSC criteria, 26 (19.1%) studies were considered 'very limited', 91 (66.9%) were 'limited' and only 19 (14.0%) studies were considered to be of a 'probably robust' in terms of methodological and reporting rigor. In fact, the quality of HRQoL reporting has not improved over time.

CONCLUSION

HRQoL is a critical consideration in CHF management, yet reporting is highly variable. There is a need to develop a standardized method for measuring and reporting HRQoL measures in clinical trials to aid in the interpretation and application of findings.

Assessment of quality of life in severe heart failure

Improvement of health-related quality of life (HRQL) is increasingly recognized as a priority in the management of heart failure (HF). In this review, we highlight the dramatic improvement in HRQL often observed in patients with severe HF and give particular emphasis to the nonpharmacologic therapy of cardiac resynchronization therapy, left ventricular assist devices, and cardiac rehabilitation. We juxtapose this to the less consistent improvement in HRQL seen with interventions aimed at treatment of acute HF syndromes. Conflicting data wherein HRQL improves in parallel to a detrimental or neutral effect on cardiovascular morbidity and mortality are also presented. We conclude with future directions and make the case for HF-specific instruments intended for the assessment of HRQL in hospitalized patients, longitudinal studies in which HRQL is followed over time, and continued attention to the preferences of those with severe and acute HF.

Acute heart failure: inotropic agents and their clinical uses

Inotropic agents are indispensable for the improvement of cardiac contractile dysfunction in acute or decompensated heart failure. Clinically available agents, including sympathomimetic amines (dopamine, dobutamine, noradrenaline) and selective phosphodiesterase-3 inhibitors (amrinone, milrinone, olprinone and enoximone) act via cAMP/protein kinase A (PKA)-mediated facilitation of intracellular Ca2+ mobilisation. Phosphodiesterase-3 inhibitors also have a vasodilatory action, which plays a role in improving haemodynamic parameters in certain patients, and are termed inodilators. The available inotropic agents suffer from risks of Ca2+ overload leading to arrhythmias, myocardial cell injury and ultimately, cell death. In addition, they are energetically disadvantageous because of an increase in activation energy and cellular metabolism. Furthermore, they lose their effectiveness under pathophysiological conditions, such as acidosis, stunned myocardium and heart failure. Pimobendan and levosimendan (that act by a combination of an increase in Ca2+ sensitivity and phosphodiesterase-3 inhibition) appear to be more beneficial among existing agents. Novel Ca2+ sensitisers that are under basic research warrant clinical trials to replace available inotropic agents.

Health-related quality of life measurement in heart failure: challenges for the new millennium

Health-related quality of life (HRQL), representing a patient-driven end point, has been increasingly emphasized in randomized clinical trials of new heart failure therapies. Measurement of HRQL depends on the use of validated instruments, with attention paid to the timing of administration and analysis of data in the context of conventional morbidity and mortality end points. In a review of HRQL measurement in heart failure drug trials published from 1966 to 1999, we found that important data, such as the number of participating subjects, are often lacking. HRQL is analyzed as a stand-alone end point without consideration of the underlying clinical trajectory of the disease. Improvements in trials methodology are warranted if quality-of-life data are to be meaningful in the determination of drug efficacy in heart failure.

Randomised comparison of losartan vs. captopril on quality of life in elderly patients with symptomatic heart failure: the losartan heart failure ELITE quality of life substudy

OBJECTIVE

To measure health-related quality-of-life (HRQoL) in elderly symptomatic heart failure patients following treatment with an angiotensin II receptor antagonist (losartan) vs. an angiotensin-converting-enzyme (ACE) inhibitor (captopril).

METHODS

Patients (age > or = 65 years) were randomised to losartan, titrated to 50 mg once daily, or captopril, titrated to 50 mg three times daily, as tolerated. Sickness Impact Profile (SIP) and Minnesota Living with Heart Failure (LIhFE) questionnaires were administered at baseline, weeks 12 and 48. Composite hypothesis testing of change in HRQoL from baseline for completers, and withdrawal for unfavourable events (death, clinical/laboratory adverse experience) was used to account for differential dropout rates.

RESULTS

In 203 patients completing the substudy (week 48), significant and comparable improvements in HRQoL from baseline were observed for both treatment groups (p < or = 0.001). Although there was a trend favouring losartan vs. captopril for the composite HRQoL endpoint (unadjusted p = 0.018, one-sided), this was not considered significant after adjusting for multiple testing. Significantly more captopril patients in the substudy subset withdrew for unfavourable reasons (19.6 vs. 10.9%, p = 0.038).

CONCLUSIONS

Significant improvements in HRQoL were observed in elderly patients with symptomatic heart failure treated with losartan and captopril long-term. A trend favouring losartan in the composite measure of drug tolerability/quality of life was not significant, but losartan was generally better tolerated than captopril in that significantly fewer losartan patients discontinued therapy.

Low-dose enoximone improves exercise capacity in chronic heart failure. Enoximone Study Group

OBJECTIVES

This study was designed to evaluate the effects of low-dose enoximone on exercise capacity.

BACKGROUND

At higher doses the phosphodiesterase inhibitor, enoximone, has been shown to increase exercise capacity and decrease symptoms in heart failure patients but also to increase mortality. The effects of lower doses of enoximone on exercise capacity and adverse events have not been evaluated.

METHODS

This is a prospective, double-blind, placebo-controlled, multicenter trial (nine U.S. centers) conducted in 105 patients with New York Heart Association class II to III, ischemic or nonischemic chronic heart failure (CHF). Patients were randomized to placebo or enoximone at 25 or 50 mg orally three times a day. Treadmill maximal exercise testing was done at baseline and after 4, 8 and 12 weeks of treatment, using a modified Naughton protocol. Patients were also evaluated for changes in quality of life and for increased arrhythmias by Holter monitoring.

RESULTS

By the protocol-specified method of statistical analysis (the last observation carried-forward method), enoximone at 50 mg three times a day improved exercise capacity by 117 s at 12 weeks (p = 0.003). Enoximone at 25 mg three times a day also improved exercise capacity at 12 weeks by 115 s (p = 0.013). No increases in ventricular arrhythmias were noted. There were four deaths in the placebo group and 2 and 0 deaths in the enoximone 25 mg three times a day and enoximone 50 mg three times a day groups, respectively. Effects on degree of dyspnea and patient and physician assessments of clinical status favored the enoximone groups.

CONCLUSIONS

Twelve weeks of treatment with low-dose enoximone improves exercise capacity in patients with CHF, without increasing adverse events.

Quality of life in chronic heart failure: cilazapril and captopril versus placebo. Cilazapril-Captopril Multicentre Group

OBJECTIVE

To measure quality of life (QOL) in patients with mild to moderate heart failure treated with angiotensin converting enzyme (ACE) inhibitors cilazapril or captopril.

DESIGN

Randomised, double blind, placebo controlled, parallel groups trial.

SUBJECTS

367 patients with New York Heart Association (NYHA) heart failure class II (62%), III (36%) or IV (1%).

METHODS

Patients were randomised to receive cilazapril 1 mg daily (n = 191) or captopril 25 mg three times daily (n = 90) for 24 weeks, or placebo for 12 weeks followed by cilazapril 1 mg daily for a further 12 weeks (n = 86). If patients had not responded after four weeks cilazapril was increased to 2.5 mg daily and captopril to 50 mg three times daily. QOL was assessed at baseline, 12, and 24 weeks using the sickness impact profile (SIP), the profile of mood states (POMS), the Mahler index of dyspnoea-fatigue, and a health status index (HSI).

RESULTS

The physical dimension of the SIP averaged 7 units at baseline and improved after 12 weeks by 2.24 units in the cilazapril group, 2.38 units in the captopril group, and 1.51 units in the placebo group. The difference between drug and placebo was therefore 0.73 units (95% CI -0.86 to 2.32) for cilazapril, and 0.87 units (95% CI -0.96 to 2.70) for captopril, with small non-significant effect sizes (a statistical method for estimating the importance of a treatment related change) of 0.12 and 0.14. Similar results were observed for the total POMS and HSI scores. Although QOL improved more on the ACE inhibitors than on placebo, the effect sizes were not significant (< or = 0.26).

CONCLUSIONS

Improvements in QOL in mild to moderate heart failure were small when treated with cilazapril or captopril compared with placebo.

Quality of life in cardiac patient research: a meta-analysis

This article reports a meta-analysis of 84 studies of quality of life (QOL) in cardiac patient populations published in the 5-year period 1987-1991. Selected methodologies and substantive characteristics of the studies are described. An overall effect size of .31 indicated a small but significant positive effect of pharmacologic, mechanical, surgical, nursing, or other treatment on QOL. No negative effect of treatment was found for any cardiovascular diagnostic category. Homogeneity analysis revealed eight potential moderators of the overall effect size: quality of study, gender of sample, time dimension, sampling method, intervention, marital status of subjects, quality-of-life dimension measured, and sample size.

Quality of life with ACE inhibitors in chronic heart failure

The randomized trials assessing the effect of angiotensin-converting enzyme (ACE) inhibitors in chronic heart failure (CHF) are reviewed. The Minnesota Living with Heart Failure Questionnaire has demonstrated the benefits of enalapril in some but not all circumstances and the Yale Dyspnea-Fatigue Index improves with lisinopril. A recent trial of both cilazapril and captopril vs. placebo employed the Sickness Impact Profile and supports the concept that ACE inhibitors have a small (and in this trial nonsignificant) beneficial effect on mobility. Other vasodilators and inotropes may also have small benefits on quality of life, such that comparisons of an ACE inhibitor with vasodilators, as was done in the V-HeFT II trial, fail to reveal any different effects on quality of life.

Assessment of patient outcome with the Minnesota Living with Heart Failure questionnaire: reliability and validity during a randomized, double-blind, placebo-controlled trial of pimobendan. Pimobendan Multicenter Research Group

To determine the reliability and validity of a patient outcome questionnaire for chronic heart failure, a randomized, double-blind, placebo-controlled, 3-month trial of pimobendan, an investigational medication with inotropic and vasodilator activities, was performed. Evaluated were 198 ambulatory patients with primarily New York Heart Association (NYHA) class III heart failure from 20 referral centers. Baseline therapy included digoxin, diuretics and, in 80%, a converting enzyme inhibitor. Oral pimobendan at 2.5 (n = 49), 5.0 (n = 51), or 10 (n = 49) mg daily or matching placebo (n = 49) was administered. The Minnesota Living with Heart Failure (LIhFE) questionnaire was a primary outcome measure, along with an exercise test. Interitem correlations identified subgroups of questions representing physical and emotional dimensions. Repeated baseline scores were highly correlated (r = 0.93), as were the physical (r = 0.89) and emotional (r = 0.88) dimension scores. Placebo did not have a significant effect with median (25th, 75th percentile) changes from baseline scores of 1 (-3, 5), 1 (-2, 3), and 0 (-1, 2), respectively (all p values greater than 0.10). The 5 mg dose significantly improved the total score, 7.5 (0, 18; p = 0.01) and the physical dimension, 4 (0, 8; p = 0.01), compared with placebo. Changes in the total (r = 0.33; p less than 0.01) and physical (r = 0.35; p less than 0.01) scores were weakly related to changes in exercise times, but corresponded well with changes in patients' ratings of dyspnea and fatigue.(ABSTRACT TRUNCATED AT 250 WORDS)