Comparison of effects on peak oxygen consumption, quality of life, and neurohormones of felodipine and enalapril in patients with congestive heart failure

Defining the role of calcium channel antagonists in heart failure due to systolic dysfunction

Calcium channel antagonists (CCAs) may either be divided into the dihydropyridines (e.g. amlodipine, felodipine, isradipine, lacidipine, nilvadipine, nifedipine, nicardipine etc.), the phenylalkylamines (e.g. verapamil) and the benzothiazepines (e.g. diltiazem) according to their chemical structure, or into first generation agents (nifedipine, verapamil and diltiazem) and second generation agents (subsequently developed dihydropyridine-derivatives). Second generation CCAs are characterized by greater selectivity for calcium channels in vascular smooth muscle cells than the myocardium, a longer duration of action and a small trough-to-peak variation in plasma concentrations. Heart failure is characterized by decreased cardiac output resulting in inadequate oxygen delivery to peripheral tissues. Although the accompanying neurohormonal activation, leading to vasoconstriction and increased blood pressure, is initially beneficial in increasing tissue perfusion, prolonged activation is detrimental because it increases afterload and further reduces cardiac output. At the level of the myocyte, heart failure is associated with increased intracellular calcium levels which are thought to impair diastolic function. These changes indicate that the CCAs would be beneficial in patients with heart failure. There has been a strong interest and increasing experience in the use of CCAs in patients with heart failure. Despite potential beneficial effects in initial small trials, findings from larger trials suggest that CCA may have detrimental effects upon survival and cardiovascular events. However, this may not necessarily be a 'class b' effect of the CCAs as there is considerable heterogeneity in the chemical structure of individual agents. Clinical experience with different CCAs in patients with heart failure includes trials that evaluated their effects on hemodynamic parameters, exercise tolerance and on symptomatology. However, the most relevant results are those from randomized clinical trials that assessed mortality as the primary endpoint. First generation CCAs have direct negative inotropic effects and even sustained release formulations have not proved any beneficial effect upon survival. With second generation CCAs, some benefit on hemodynamic parameters has been observed but none on survival, alone or in combination with ACE inhibitors. It is noteworthy that although amlodipine had a neutral effect on morbidity and mortality in large, randomized, placebo-controlled trials in patients with heart failure, the drug was well tolerated. There is no specific indication for CCAs (first or second generation) in patients with systolic heart failure, alone or in combination with ACE inhibitors, but amlodipine may be a considered in the management of hypertension or coronary artery disease in patients with heart failure.

[Head-to-head comparison of clinical, biochemical and functional effects of fosinopril and enalapril in patients with systolic heart failure]

INTRODUCTION

The aim of this study was to evaluate short-term clinical, biochemical and functional effects of fosinopril versus enalapril in patients with heart failure.

MATERIAL AND METHODS

59 consecutive patients (mean age 57 +/- 8 years, EF 18.9 +/- 6.3%, NYHA III or IV class 19/59) were randomized to receive fosinopril or enalapril for three months. All patients underwent echocardiography, metabolic testing, and a 6-minute walk test and completed the Minnesota questionnaire on inclusion and three months later. Additionally, serum creatinine, BUN, total cholesterol and triglycerides were measured. Kaplan-Meier curve was created to assess event-free survival for cardiac death and hospitalization for heart failure.

RESULTS

There was no statistically significant difference in event-free survival between patients on fosinopril and enalapril (86.7% vs. 82.8%, log rank 4.21 p=0.43). However, time to the event was longer in patients on fosinopril (77.0 +/- 25.35 vs. 40.2 +/- 6.8 days, p=0.04). At the end of the study, no difference between fosinopril and enalapril group existed with respect to maximal oxygen consumption (20.90 +/- 4.47 vs. 20.89 +/- 6.86 ml/kg/min), ejection fraction (20.5 +/- 7.4 vs. 21.4 +/- 7.8%), distance during the 6-minute test walk (313 +/- 74 vs. 352 +/- 129 meters) and quality of life (23.8 +/- 15.8 vs. 25.6 +/- 20.3 points), but patients on enalapril had higher creatinine (99 +/- 13 vs. 113 +/- 17 micromol/L, p=0.002) and BUN (7.28 +/- 1.7 vs. 8.89 +/- 2.39 mmol/L, p=0.01) levels. Increase in fosinopril dose during the study was higher than increase in enalapril dose (24.1% +/- 23.8% vs. 9.5 +/- 24.5%, p=0.04).

CONCLUSIONS

Fosinopril and enalapril have similar short-term effects on event-free survival, ejection fraction, functional capacity and quality of life in patients with heart failure. Patients on fosinopril presented with longer survival without event and had lower creatinine and BUN at the end-of the follow-up. Additionally, fosinopril can be easily titrated to the maximum therapeutic dose.

Effects of low-dose treatment with felodipine versus fosinopril in Chinese patients with nonischemic heart failure and normal blood pressure: A double-blind, randomized, crossover study

BACKGROUND

Two second-generation calcium channel blockers, felodipine and amlodipine besylate, have been associated with similar high mortality rates in patients with ischemic heart failure (HF) but not in patients with nonischemic causes of HF. In patients with nonischemic HF, amlodipine might have a beneficial effect on survival. However, no difference in mortality rates was found between felodipine and placebo in a nonischemic HF group. Felodipine 10 mg/d was used in 1 large study, a dose considered high for nonischemic HF usually associated with normal blood pressure (BP).

OBJECTIVE

The aim of this study was to compare the effects of 12-week, low-dose treatment with felodipine versus those of an angiotensin-converting enzyme inhibitor, fosinopril sodium, in patients with nonischemic HF and normal BP.

METHODS

This double-blind, randomized, crossover trial was conducted at Taipei Medical University Hospital (Taipei, Taiwan). Patients aged ≥ 18 years with angiographically proved, nonischemic HF and normal BP who were being treated with an optimal regimen of digitalis and diuretics were enrolled. After a 2-week run-in period, patients were randomized to first receive 12 weeks of treatment with felodipine tablets (2.5 mg/d) or fosinopril tablets (7.5 mg/d) and, after a 2-week washout period, were crossed over to the opposite treatment. Efficacy analysis was performed before (baseline) and after treatment and included symptomatic assessment using a 7-grade clinical scale; 2-dimensional echocardiography (2-D echo); exercise tests; and neurohumoral data, including plasma renin activity, plasma aldosterone, and 24-hour urinary epinephrine (E) and norepinephrine (NE) measurements. The primary end point was death due to HF, and the secondary end point was hospital admission due to worsening HF. Compliance was measured using a pill count at the end of each treatment period.

RESULTS

We enrolled 33 patients. One developed worsening HF during the run-in period and was admitted. A total of 32 patients entered the study (18 men, 14 women; mean [SD] age, 48.2 [6.3] years [range, 34-56 years]; mean [SD] systolic BP, 117.2 [9.8] mm Hg [range, 100-138 mm Hg]; mean [SD] diastolic BP, 59.4 [5.7] mm Hg [range, 50-72 mm Hg]). No hospital admission or cardiac death due to HF occurred during 12 weeks of treatment. Twenty-seven patients were included in the felodipine assessment, and 30 patients were included in the fosinopril assessment. Significant improvement in clinical score was noted in both treatment groups (both P < 0.01). The clinical scores did not differ significantly between the 2 treatments. No significant differences were found in 2-D echo parameters between treatments or within groups after treatment versus baseline. Significant improvement in exercise duration was noted with both study drugs after treatment versus baseline (both P < 0.01). No significant difference in exercise duration was found between the 2 treatments. Urinary E and NE were not significantly different between treatments or after treatment with either study drug compared with baseline.

CONCLUSION

The present findings suggest that, in Chinese patients with moderate to severe HF who have normal BP and insignificant coronary artery disease and were being treated with diuretics and digitalis, a 12-week, low-dose course of felodipine (2.5 mg/d) as a vasodilator was associated with as satisfactory an outcome as standard treatment with fosinopril (7.5 mg/d).

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.

Meta-analysis of efficacy and safety of second-generation dihydropyridine calcium channel blockers in heart failure

Second-generation dihydropyridine calcium channel blockers slightly increase cardiac index, left ventricular ejection fraction, and exercise treadmill tests in patients with chronic heart failure, and do not increase norepinephrine levels; these drugs seem to be safe and beneficial in this category of patients. A 6% reduction in mortality was found, which, although not significantly different from 0%, does indicate that these drugs do not increase mortality in this category of patients.

Diastolic dysfunction in the elderly. Genesis and diagnostic and therapeutic implications

Diastolic left ventricular function is altered substantially with advancing age in healthy persons, and diastolic dysfunction impacts most cardiovascular disorders in the elderly. Older, healthy persons have a delayed relaxation Doppler filling pattern and their early deceleration time is similar to, or modestly lengthened, compared with younger, healthy persons. Two abnormal Doppler filling patterns, the pseudo-normal and the restricted, are discerned more easily, and are more specific in the elderly than the young, because they are the opposite (reverse) of the normal elderly pattern. Most heart failure in the elderly occurs in the presence of preserved systolic function (presumed diastolic heart failure). Elderly patients with diastolic heart failure tend to be women with hypertrophied, hyperdynamic left ventricles, and chronic hypertension. Prognosis may be somewhat better than in systolic heart failure, but the difference diminishes when adjusted for gender and in the very elderly. The pathophysiology of this disorder is not well characterized, diagnostic criteria have not been standardized, and there are no large, multicenter, randomized trials to guide therapy. Further research in this area should be a high priority.

Heart failure with normal systolic function

Contrary to popular belief, population studies indicate that most elderly patients with heart failure have preserved left ventricular systolic function (i.e., presumed diastolic heart failure). Several normal aging changes may predispose older individuals to diastolic heart failure, including increased hypertrophy and stiffness of the left ventricle, increased vascular stiffness, and decreased cardiovascular reserve. Progress in diastolic heart failure has been hindered by a lack of standard case definition; absence of a readily available, reliable test to quantitate diastolic function; poor understanding of the pathophysiology of heart failure; and lack of data from randomized, controlled, multicenter trials. Typical patients are older women with chronic hypertension, left ventricular hypertrophy, chronic exercise intolerance, and occasional acute exacerbations (pulmonary edema). Although heart failure is a clinical, bedside diagnosis, echocardiography is helpful in differentiating diastolic from systolic heart failure and in ruling out other disorders. Although optimal pharmacologic therapy has not been clarified, control of blood pressure; exercise conditioning; and a multidisciplinary, case management approach seem beneficial.

The clinical significance of neurohormonal activation

Progressive heart disease after the onset of left ventricular dysfunction has typically been attributed to hemodynamic factors. As left ventricular function declines, decreased cardiac output and tissue hypoperfusion lead to compensatory increases in afterload, preload, and heart rate. The purpose of these compensatory responses is to increase cardiac output and maintain tissue perfusion; however, they may also create hemodynamic stress for the failing heart. However, this does not explain the progression of heart failure despite hemodynamic maintenance with pharmacologic therapy. Activation of neurohormonal systems that are essential for homeostasis in the normal heart plays a key role in the progression of heart failure. In acute heart failure, these systems have beneficial effects, but in chronic heart failure their activation produces deleterious effects by increasing the load on the left ventricle and promoting structural remodeling, which may further impair left ventricular function. The issue of neurohormonal activation is an important one in cardiovascular medicine, not only for patients with heart failure but also for patients with hypertension and ischemic heart disease when left ventricular dysfunction is present. As neurohormonal activation may play a pathogenic role in the long-term outcome of patients, interventions that have favorable hemodynamic but unfavorable neurohormonal effects can actually exacerbate cardiac disease and may increase cardiovascular morbidity and mortality. As neurohormonal activation appears to parallel the severity of heart failure, whether assessed according to symptoms or prognosis, an understanding of neurohormonal activation and its interaction with hemodynamic factors is essential for optimizing pharmacologic therapy for cardiovascular disease.

Safety of calcium antagonists in patients with congestive heart failure

Continuing high morbidity and mortality have spurred an ongoing search for new therapeutic agents for patients with congestive heart failure. Calcium antagonists (CAs) have been under active investigation in patients with heart failure since their introduction into clinical medicine, because their anti-ischemic and vasodilator properties were thought to be of potential benefit in this patient population. However, review of published clinical trials of CAs in patients with heart failure reveals that some of these drugs are associated with detrimental effects, including acute hemodynamic deterioration, increased symptoms of heart failure, and increased mortality. The adverse effects of short-acting CAs in patients with heart failure include negative inotropic effects and neurohormonal activation. Long-acting CAs, such as amlodipine and felodipine, had fewer negative inotropic effects, showed less evidence of neurohormonal activation, and were better tolerated in clinical trials. Amlodipine, in combination with an angiotensin-converting enzyme inhibitor, had a neutral effect in patients with ischemic heart failure and an unexplained benefit in a subgroup of patients with non-ischemic cardiomyopathy. Although the preliminary experience with long-acting dihydropyridine CAs in heart failure has been encouraging, safety concerns raised by past trials dictate that no CA can be recommended for the treatment of heart failure at this time.

Effects of amlodipine on endothelial function in rats with chronic heart failure after experimental myocardial infarction

In chronic heart failure, the role of endothelial dysfunction is not yet well established. As calcium metabolism plays an important role in the endothelium, it might be suggested that calcium channel blockers influence endothelial function. Although calcium channel blockers are generally contraindicated in chronic heart failure, because they are believed to stimulate neurohumoral mechanisms and to exert negative inotropic effects, recently it has been suggested that amlodipine might have a favorable affect on mortality in patients with heart failure. The mechanism of amlodipine that contributes to this beneficial effect is not known. Therefore we investigated whether 10 weeks of amlodipine treatment could influence endothelial function in rats with congestive heart failure induced by myocardial infarction. The main finding of our study was that amlodipine, when administered for 10 weeks to rats after a myocardial infarction had been induced, had no significant effects on in vitro and in vivo hemodynamics or neurohormones. The effect of amlodipine on endothelium-intact, norepinephrine-precontracted aortic rings appears to differ from the placebo treatment with respect to the endothelium-dependent relaxation, whereas no differences are seen in endothelium-independent relaxation. We conclude that our data do not support a beneficial role of amlodipine on endothelial function in chronic heart failure.

Long-term effects of angiotensin-converting enzyme inhibitors and calcium antagonists on the right and left ventricles in essential hypertension

To compare the effects of chronic antihypertensive treatment on left and right ventricular structure and function, 24 patients with mild to moderate, never-treated hypertension were randomized to receive fosinopril (20 mg daily) or amlodipine (10 mg daily) for 12 months. At baseline and subsequently at the end of third, sixth, and twelfth months, each patient underwent an integrated echocardiographic study and noninvasive ambulatory blood pressure monitoring. Both drugs significantly reduced blood pressure, casual or monitored (p < 0.01), and left ventricular mass index (from 125 +/- 32 to 100 +/- 12 gm/m2 [p < 0.02] with amlodipine and from 106 +/- 18 to 89 +/- 10 gm/m2 [p < 0.02] with fosinopril). The decrease in left ventricular mass was essentially caused by a reduction of ventricular thickness. Free right ventricular wall thickness was also lowered in both groups, more consistently with amlodipine (from 8.0 +/- 2.1 to 6.4 +/- 0.8 mm; p < 0.01), without an increase in plasma natriuretic peptide and insulin concentrations or heart rate. With both treatments, the decrease in ventricular mass was not associated with impairment of systolic function, whereas a trend toward an improvement of Doppler echocardiographic indexes of biventricular diastolic function was observed. In conclusion, both amlodipine and fosinopril induced similar qualitative effects on anatomy and function of both ventricles. The clinical meaning of these observations must be defined further by means of adequately sized prospective trials.