Tolerability and efficacy of carvedilol in patients with New York Heart Association class IV heart failure

Adverse Drug Reactions to Guideline-Recommended Heart Failure Drugs in Women: A Systematic Review of the Literature

OBJECTIVES

This study sought to summarize all available evidence on sex differences in adverse drug reactions (ADRs) to heart failure (HF) medication.

BACKGROUND

Women are more likely to experience ADRs than men, and these reactions may negatively affect women's immediate and long-term health. HF in particular is associated with increased ADR risk because of the high number of comorbidities and older age. However, little is known about ADRs in women with HF who are treated with guideline-recommended drugs.

METHODS

A systematic search of PubMed and EMBASE was performed to collect all available information on ADRs to angiotensin-converting enzyme inhibitors, β-blockers, angiotensin II receptor blockers, mineralocorticoid receptor antagonists, ivabradine, and digoxin in both women and men with HF.

RESULTS

The search identified 155 eligible records, of which only 11 (7%) reported ADR data for women and men separately. Sex-stratified reporting of ADRs did not increase over the last decades. Six of the 11 studies did not report sex differences. Three studies reported a higher risk of angiotensin-converting enzyme inhibitor-related ADRs in women, 1 study showed higher digoxin-related mortality risk for women, and 1 study reported a higher risk of mineralocorticoid receptor antagonist-related ADRs in men. No sex differences in ADRs were reported for angiotensin II receptor blockers and β-blockers. Sex-stratified data were not available for ivabradine.

CONCLUSIONS

These results underline the scarcity of ADR data stratified by sex. The study investigators call for a change in standard scientific practice toward reporting of ADR data for women and men separately.

GDMT for heart failure and the clinician's conundrum

Therapeutic advances in management of CHF have decreased mortality and have impacted progression in patients with mild to moderate heart failure. Aggressive campaigns by cardiology societies aimed at increasing implementation of these measures in routine practices have almost generalized the treatment of heart failure irrespective of individual variations of clinical status of patients and stages of heart failure. This explains why morbidity compression and quality of life improvement have not been realized fully particularly in patients with advanced disease. To examine whether GDMT for CHF is backed by unambiguous evidence of clinical efficacy for its global implementation in every patient at all stages of the syndrome. ACC/AHA, ESC Guidelines for CHF, and their updates were reviewed. Clinical trial cited in the guideline documents and other pertaining published literatures were analyzed.

Findings

Many of the recommended GDMT for CHF lack unequivocal evidence of clinical efficacy in patients with diverge etiology of heart failure and concomitant comorbid conditions Some of the recommendations which are useful in early stages, lack evidence of efficacy in more advanced stages of heart failure. Application of results of research trials in patients beyond their inclusion and exclusion criteria, appears mere extrapolation, Clinicians are faced with the conundrum of implementing the recommendations without indubitable evidence of their efficacy in every patient of their practice.

Conclusion

A reappraisal of Guidelines is needed to address outstanding questions pertaining to the efficacy of recommendations and plug the knowledge gaps without assumption and extrapolation of results of RCTs beyond their inclusion and exclusion criteria.

Baroreflex activation therapy: a new approach to the management of advanced heart failure with reduced ejection fraction

Chronic heart failure is a common clinical condition characterized by persistent excessive sympathetic nervous system activation. The derangement of the sympathetic activity has relevant implications for disease progression and patient survival. Aiming to positively impact patient outcome, autonomic nervous system modulatory therapies have been developed and tested in animal and clinical studies. As a general gross assumption, direct vagal stimulation and baroreflex activation are considered equivalent. This assumption does not take into account the fact that direct cervical vagal nerve stimulation involves activation of both afferent and efferent fibers innervating not only the heart, but the entire visceral system, leading to undesired responses to and from this compartment. The different action of baroreflex activation is based on generating a centrally mediated reduction of sympathetic outflow and increasing parasympathetic activity to the heart via a physiological reflex pathway. Thus, baroreflex activation rebalances the unbalanced autonomic nervous system via a specific path. Independent and complementary investigations have shown that sympathetic nerve activity can be rebalanced via control of the arterial baroreflex in heart failure patients.

Results from recent pioneering research studies support the hypothesis that baroreflex activation can add significant therapeutic benefit on top of guideline-directed medical therapy in patients with advanced heart failure. In the present review, baroreflex activation therapy results are discussed, focusing on critical aspects like patient selection rationale to support clinician orientation in opting for baroreflex activation therapy when, on top of current guideline-directed medical treatment, other therapies are to be considered.

Effects of carvedilol on structural and functional outcomes and plasma biomarkers in the mouse transverse aortic constriction heart failure model

INTRODUCTION

Despite the widespread use of the mouse transverse aortic constriction heart failure model, there are no reports on the characterization of the standard-of-care agent carvedilol in this model.

METHODS

Left ventricular pressure overload was produced in mice by transverse aortic constriction between the innominate and left common carotid arteries. Carvedilol was administered at multiple dose levels (3, 10 and 30 mg/kg/day per os; yielding end-study mean plasma concentrations of 0.002, 0.015 and 0.044 µM, respectively) in a therapeutic design protocol with treatment initiated after the manifestation of left ventricular remodeling at 3 weeks post transverse aortic constriction and continued for 10 weeks.

RESULTS

Carvedilol treatment in transverse aortic constriction mice significantly decreased heart rate and left ventricular dP/dt (max) at all dose levels consistent with β-adrenoceptor blockade. The middle dose of carvedilol significantly decreased left ventricular weight, whereas the higher dose decreased total heart, left and right ventricular weight and wet lung weight compared to untreated transverse aortic constriction mice. The higher dose of carvedilol significantly increased cardiac performance as measured by ejection fraction and fractional shortening and decreased left ventricular end systolic volume consistent with the beneficial effect on cardiac function. End-study plasma sST-2 and Gal-3 levels did not differ among sham, transverse aortic constriction control and transverse aortic constriction carvedilol groups. Plasma brain natriuretic peptide concentrations were elevated significantly in transverse aortic constriction control animals (~150%) compared to shams in association with changes in ejection fraction and heart weight and tended to decrease (~30%, p = 0.10-0.12) with the mid- and high-dose carvedilol treatment.

CONCLUSION

A comparison of carvedilol hemodynamic and structural effects in the mouse transverse aortic constriction model versus clinical use indicates a strong agreement in effect profiles preclinical versus clinical, providing important translational validation for this widely used animal model. The present plasma brain natriuretic peptide biomarker findings support the measurement of plasma natriuretic peptides in the mouse transverse aortic constriction model to extend the translational utility of the model.

Novel role of phosphodiesterase inhibitors in the management of end-stage heart failure

In advanced heart failure (HF), chronic inotropic therapy with intravenous milrinone, a phosphodiesterase III inhibitor, is used as a bridge to advanced management that includes transplantation, ventricular assist device implantation, or palliation. This is especially true when repeated attempts to wean off inotropic support result in symptomatic hypotension, worsened symptoms, and/or progressive organ dysfunction. Unfortunately, patients in this clinical predicament are considered hemodynamically labile and may escape the benefits of guideline-directed HF therapy. In this scenario, chronic milrinone infusion may be beneficial as a bridge to introduction of evidence based HF therapy. However, this strategy is not well studied, and in general, chronic inotropic infusion is discouraged due to potential cardiotoxicity that accelerates disease progression and proarrhythmic effects that increase sudden death. Alternatively, chronic inotropic support with milrinone infusion is a unique opportunity in advanced HF. This review discusses evidence that long-term intravenous milrinone support may allow introduction of beta blocker (BB) therapy. When used together, milrinone does not attenuate the clinical benefits of BB therapy while BB mitigates cardiotoxic effects of milrinone. In addition, BB therapy decreases the risk of adverse arrhythmias associated with milrinone. We propose that advanced HF patients who are intolerant to BB therapy may benefit from a trial of intravenous milrinone as a bridge to BB initiation. The discussed clinical scenarios demonstrate that concomitant treatment with milrinone infusion and BB therapy does not adversely impact standard HF therapy and may improve left ventricular function and morbidity associated with advanced HF.

Weaning from inotropic support and concomitant beta-blocker therapy in severely ill heart failure patients: take the time in order to improve prognosis

AIMS

Beta-blockers improve the prognosis in heart failure (HF), but their introduction may seem impossible in patients dependent on inotropic support. However, many of these patients can be titrated on beta-blockers, but there is little evidence of successful clinical strategies.

METHODS AND RESULTS

We analysed the records of inotropy-dependent patients referred for assessment for heart transplantation. Thirty-six patients (45%) could not be weaned (NW) and underwent left ventricular assist device (LVAD) implantation or transplantation, or died. However, 44 (55%) were successfully weaned (SW). Neither the aetiology (ischaemic vs. non-ischaemic) nor cardiac indexes were different in the SW as compared with the NW group (2.27±0.5 vs. 2.15±0.6 L/min/m2). The NW patients had lower LVEF (15±5% vs. 19±5%, P=0.001), higher right atrial pressure (12±6 vs. 8±6 mmHg, P=0.02), and more severe mitral regurgitation (P<0.001) than the SW patients. At discharge, 35 of 44 SW patients were receiving beta-blockers. In 29 of them, a beta-blocker could only be initiated or continued during concomitant support with i.v. enoximone for a duration of 14.1±7.2 days. Patients discharged on a beta-blocker had an LVAD/transplantation-free cumulative survival of 71% during a follow-up of 2074±201 days (confidence interval 1679–2470).

CONCLUSION

It takes time to put severely ill HF patients on beta-blockers and it may require bridging with inotropes which are independent of beta-adrenergic receptors. Whether such a strategy may result in a better clinical outcome warrants further research.

Outpatient management of chronic heart failure

INTRODUCTION

Heart failure (HF) treatment attracts a share of intensive research because of its poor HF prognosis. In the past decades, the prognosis of HF has improved considerably, mainly as a consequence of the progress that has been made in the pharmacological management of HF.

AREAS COVERED

This article reviews the outpatient pharmacological management of chronic HF due to left ventricular systolic dysfunction and offers recommendations on the use of various drugs. In addition, the present article attempts to provide practical therapeutic algorithms based on current clinical strategies.

EXPERT OPINION

Continued research directed toward identifying factors associated with high pharmacotherapy guideline adherence and understanding of variants that influence response to drugs will hopefully halt or reverse the major pathophysiological mechanisms involved in this syndrome.

Beneficial association of β-blocker therapy on recovery from severe acute heart failure treatment: data from the Survival of Patients With Acute Heart Failure in Need of Intravenous Inotropic Support trial

OBJECTIVES

Beta-blocker therapy is recommended for most patients with chronic heart failure, although such therapy may be discontinued or reduced during hospitalizations. The aim is to determine whether β-blocker use at study entry and/or at discharge has an impact on 31- and 180-day survival.

DESIGN

Survival of Patients With Acute Heart Failure in Need of Intravenous Inotropic Support study was designed as a randomized, double-blind, active-controlled, multi-center study.

SETTING

Multinational.

PATIENTS

A total of 1,327 critically ill patients hospitalized with low-output heart failure in need of inotropic therapy.

INTERVENTION

Levosimendan versus dobutamine.

MEASUREMENTS

All-cause mortality at 31 and 180 days in patients who survived initial hospitalization with/without β-blocker use at entry and/or at discharge.

RESULTS

Patients on β-blockers at entry and at discharge had significantly lower 31-day (p < .0001) and 180-day (p < .0001) mortality compared to patients without β-blockers use at both time points. The association was robust when adjusted for age and co-morbidities (p = .006 at 31 days; p = .003 at 180 days).

CONCLUSIONS

Those results strongly suggest, in severe acutely decompensated heart failure patients, admitted on β-blockers, to continue on them at discharge.

A randomised, placebo-controlled trial of carvedilol in early familial dilated cardiomyopathy

BACKGROUND

Screening of asymptomatic relatives of patients with dilated cardiomyopathy (DCM) has identified a population of individuals with left ventricular dilatation and/or minimally impaired contraction who are believed to have early disease. A proportion of these individuals with early disease progress to overt cardiomyopathy, however to our knowledge there have been no studies that have examined the impact of early intervention on disease progression.

METHODS

We evaluated 424 asymptomatic relatives in 110 families of probands with DCM and identified 102 individuals (24%) with suspected "early disease" (EDCM). Thirty-two EDCM subjects were randomised into a six-month placebo-controlled trial of the β-blocker, carvedilol. Transthoracic echocardiography and plasma nt-proBNP levels were measured at baseline and repeated at six months. The primary trial endpoint was change in left ventricular end-systolic diameter after six months. Subjects completing six months of blinded trial therapy were offered open-label carvedilol and then observed over an extended period with repeated clinical evaluation and echocardiography.

RESULTS

At baseline, left ventricular dimensions, systolic function and plasma nt-proBNP levels were similar in carvedilol and placebo groups. There were no significant changes observed in these parameters in either treatment group after six months, however reductions in end-diastolic diameter (% predicted) were observed in carvedilol-treated subjects (P=0.002) during an open-label median follow-up of 32 months (range: 13-56 months).

CONCLUSIONS

In an asymptomatic population of individuals with EDCM, treatment with carvedilol for six months had no effect on echocardiographic left ventricular dimensions or systolic function, however longer-term treatment may reverse left ventricular remodelling (Australian Clinical Trials Registry N012605000204640).

Interest of β-blockers in patients with right ventricular systemic dysfunction

BACKGROUND

β-blockers improve the prognosis of patients with cardiac failure due to left ventricular systolic dysfunction. The aim of this study was to assess the efficacy of β-blockers in patients with dysfunctional systemic right ventricle.

METHODS

Fourteen patients with systemic right ventricle following a Mustard or a Senning operation for the transposition of the great arteries, or congenitally corrected transposition were included in the study. All had a decreased systemic right ventricular ejection fraction despite having standard cardiac failure therapy. Quality of life, New York Heart Association class, aerobic capacity, and systemic right ventricular function were assessed before treatment with β-blockers and at the end of the follow-up period, mean of 12.8 months with a range from 3 to 36 months.

RESULTS

Change in New York Heart Association class was significant (p = 0.016). Quality of life improved significantly throughout the study from a median grade 2 with a range from 1 to 3 to a median grade 1 with a range from 1 to 2 (p = 0.008). Systemic right ventricular ejection fraction assessed by radionuclide ventriculography improved significantly from a median of 41% (range: 29-53%) to 49% (range: 29-62%; p = 0.031). However, the change in thee ejection fraction assessed by magnetic resonance imaging was not significant from a median of 29% (range: 12-47%) to 32% (range: 22-63%; p = 0.063).

CONCLUSION

In patients with cardiac failure due to systemic right ventricular dysfunction, β-blockers improve New York Heart Association class, quality of life, and systemic right ventricular ejection fraction assessed by radionuclide ventriculography.

Differences between beta-blockers in patients with chronic heart failure and chronic obstructive pulmonary disease: a randomized crossover trial

OBJECTIVES

The purpose of this study was to determine the respiratory, hemodynamic, and clinical effects of switching between beta1-selective and nonselective beta-blockers in patients with chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD).

BACKGROUND

Carvedilol, metoprolol succinate, and bisoprolol are established beta-blockers for treating CHF. Whether differences in beta-receptor specificities affect lung or vascular function in CHF patients, particularly those with coexistent COPD, remains incompletely characterized.

METHODS

A randomized, open label, triple-crossover trial involving 51 subjects receiving optimal therapy for CHF was conducted in 2 Australian teaching hospitals. Subjects received each beta-blocker, dose-matched, for 6 weeks before resuming their original beta-blocker. Echocardiography, N-terminal pro-hormone brain natriuretic peptide, central augmented pressure from pulse waveform analysis, respiratory function testing, 6-min walk distance, and New York Heart Association (NYHA) functional class were assessed at each visit.

RESULTS

Of 51 subjects with a mean age of 66 +/- 12 years, NYHA functional class I (n = 6), II (n = 29), or III (n = 16), and left ventricular ejection fraction mean of 37 +/- 10%, 35 had coexistent COPD. N-terminal pro-hormone brain natriuretic peptide was significantly lower with carvedilol than with metoprolol or bisoprolol (mean: carvedilol 1,001 [95% confidence interval (CI): 633 to 1,367] ng/l; metoprolol 1,371 [95% CI: 778 to 1,964] ng/l; bisoprolol 1,349 [95% CI: 782 to 1,916] ng/l; p < 0.01), and returned to baseline level on resumption of the initial beta-blocker. Central augmented pressure, a measure of pulsatile afterload, was lowest with carvedilol (carvedilol 9.9 [95% CI: 7.7 to 12.2] mm Hg; metoprolol 11.5 [95% CI: 9.3 to 13.8] mm Hg; bisoprolol 12.2 [95% CI: 9.6 to 14.7] mm Hg; p < 0.05). In subjects with COPD, forced expiratory volume in 1 s was lowest with carvedilol and highest with bisoprolol (carvedilol 1.85 [95% CI: 1.67 to 2.03] l/s; metoprolol 1.94 [95% CI: 1.73 to 2.14] l/s; bisoprolol 2.0 [95% CI: 1.79 to 2.22] l/s; p < 0.001). The NYHA functional class, 6-min walk distance, and left ventricular ejection fraction did not change. The beta-blocker switches were well tolerated.

CONCLUSIONS

Switching between beta1-selective beta-blockers and the nonselective beta-blocker carvedilol is well tolerated but results in demonstrable changes in airway function, most marked in patients with COPD. Switching from beta1-selective beta-blockers to carvedilol causes short-term reduction of central augmented pressure and N-terminal pro-hormone brain natriuretic peptide. (Comparison of Nonselective and Beta1-Selective Beta-Blockers on Respiratory and Arterial Function and Cardiac Chamber Dynamics in Patients With Chronic Stable Congestive Cardiac Failure; Australian New Zealand Clinical Trials Registry, ACTRN12605000504617).

Should beta-blocker therapy be reduced or withdrawn after an episode of decompensated heart failure? Results from COMET

BACKGROUND

It is unclear whether beta-blocker therapy should be reduced or withdrawn in patients who develop acute decompensated heart failure (HF). We studied the relationship between changes in beta-blocker dose and outcome in patients surviving a HF hospitalisation in COMET.

METHODS

Patients hospitalised for HF were subdivided on the basis of the beta-blocker dose administered at the visit following hospitalisation, compared to that administered before.

RESULTS

In COMET, 752/3029 patients (25%, 361 carvedilol and 391 metoprolol) had a non-fatal HF hospitalisation while on study treatment. Of these, 61 patients (8%) had beta-blocker treatment withdrawn, 162 (22%) had a dose reduction and 529 (70%) were maintained on the same dose. One-and two-year cumulative mortality rates were 28.7% and 44.6% for patients withdrawn from study medication, 37.4% and 51.4% for those with a reduced dosage (n.s.) and 19.1% and 32.5% for those maintained on the same dose (HR,1.59; 95%CI, 1.28-1.98; p<0.001, compared to the others). The result remained significant in a multivariable model: (HR, 1.30; 95%CI, 1.02-1.66; p=0.0318). No interaction with the beneficial effects of carvedilol, compared to metoprolol, on outcome was observed (p=0.8436).

CONCLUSIONS

HF hospitalisations are associated with a high subsequent mortality. The risk of death is higher in patients who discontinue beta-blocker therapy or have their dose reduced. The increase in mortality is only partially explained by the worse prognostic profile of these patients.

Tolerability and dose-related effects of nebivolol in elderly patients with heart failure: data from the Study of the Effects of Nebivolol Intervention on Outcomes and Rehospitalisation in Seniors with Heart Failure (SENIORS) trial

BACKGROUND

The SENIORS trial showed that nebivolol reduced the risk of death or cardiovascular (CV) hospitalization in elderly patients with heart failure (HF). We aimed to assess tolerability and dose-related effects of the beta-blocker nebivolol in elderly patients from the SENIORS trial.

METHODS

Patients assigned to nebivolol (n = 1031) were classified into 4 groups, according to the dose achieved at the end of titration phase (maintenance dose): 0 mg (n = 74), low dose (1.25 or 2.5 mg, n = 142), medium dose (5 mg, n = 127), and target dose (10 mg, n = 688) and compared with those allocated to placebo (n = 1030). Age, sex and ejection fraction were similar between the groups, but prior myocardial infarction, coronary revascularization, and serum creatinine levels were lower in patients who achieved higher maintenance doses of nebivolol.

RESULTS

After adjustment, all-cause mortality or CV hospitalization was significantly reduced in the 10 mg dose group compared with placebo (hazard ratio [HR] 0.75, 95% CI 0.63-0.90) which was similar to the medium dose group (HR 0.73, 95% CI 0.52-1.02). The low dose group had an apparently lower benefit (HR 0.88, 95% CI 0.64-1.20), whereas patients unable to tolerate any dose of nebivolol had an increased risk of death or CV hospitalization (HR 1.95, 95% CI 1.38-2.75).

CONCLUSIONS

The benefits of nebivolol in elderly patients with HF appear to be related to the maintenance dose achieved. Patients unable to tolerate any dose have the worst prognosis.

Diagnostic and therapeutic challenges in patients with coexistent chronic obstructive pulmonary disease and chronic heart failure

Chronic obstructive pulmonary disease (COPD) and heart failure (CHF) are common conditions. The prevalence of COPD ranges from 20% to 30% in patients with CHF. The diagnosis of CHF can remain unsuspected in patients with COPD, because shortness of breath is attributed to COPD. Measurement of plasma B-type natriuretic peptide (BNP) levels helps to uncover unsuspected CHF in patients with COPD and clinical deterioration. Noninvasive assessment of cardiac function may be preferable to BNP to uncover unsuspected left ventricular (LV) systolic dysfunction in patients with stable COPD. Patients with COPD or CHF develop skeletal muscle alterations that are strikingly similar. Functional intolerance correlates with severity of skeletal muscle alterations but not with severity of pulmonary or cardiac impairment in COPD and CHF, respectively. Improvement of pulmonary or cardiac function does not translate into relief of functional intolerance in patients with COPD or CHF unless skeletal muscle alterations concomitantly regress. The mechanisms responsible for skeletal muscle alterations are incompletely understood in COPD and in CHF. Disuse and low-level systemic inflammation leading to protein synthesis/degradation imbalance are likely to contribute. The presence of COPD impacts on the treatment of CHF, as COPD is still viewed as a contraindication to beta-blockade. Therefore, COPD often deprives patients with CHF due to LV systolic dysfunction of the most beneficial pharmacologic intervention. A large body of data indicates that patients with COPD tolerate well selective beta-blockade that should not be denied to CHF patients with concomitant COPD.

Novel use of a short-acting intravenous beta blocker in combination with inotropic therapy as a bridge to chronic oral beta blockade in patients with advanced heart failure

The role for beta blockers in advanced heart failure (New York Heart Association class IV) remains undefined because of concerns about tolerability and uncertainty about efficacy. We report the use of a short-acting intravenous beta blocker in combination with inotropic therapy as a means to bridge five patients with advanced heart failure to chronic oral beta blockade; two of these patients had been chronically managed with intravenous inotrope. At 4 months' follow-up, all patients remained on beta-blocker therapy and none was hospitalized for heart failure or had received intravenous diuretics. Given the early separation of survival curves in the randomized clinical trials of beta blockers in heart failure, it is possible that these patients will accrue a survival benefit. We conclude that some patients with advanced heart failure can be offered oral beta-blocker therapy by bridging with a combination of intravenous inotrope and short-acting intravenous beta blocker.

Does atrial fibrillation in very elderly patients with chronic systolic heart failure limit the use of carvedilol?

BACKGROUND AND AIMS

It is well known that beta-blockers are useful in patients with chronic heart failure (CHF). These favourable effects have recently been observed even in elderly CHF patients. Objectives of the present study were to evaluate the feasibility, tolerability and safety of carvedilol therapy in a cohort of patients > 70 years of age with CHF and left ventricular ejection fraction < 40% with chronic atrial fibrillation. For this purpose, we designed an observational, 12-month prospective study.

RESULTS

Among 240 patients who were referred to our centers and met inclusion criteria, 64 had chronic atrial fibrillation (27%). Thirty-nine out of these 64 subjects (61%) were treated with carvedilol, while 25 patients (39%) had contraindications to such treatment. In the cohort of 176 patients with stable sinus rhythm (control group), carvedilol could be administered in 121 patients (69%), while it was not given in 55 (31%, p=ns). Airways disease was the main reason for exclusion from carvedilol in this setting of patients. No difference in 1-year tolerability of study drug was observed among patients with chronic atrial fibrillation (29 of 33 patients=87.9%) and stable sinus rhythm (95 of 102=93.1%). Adverse events leading to the discontinuation of carvedilol in these two populations were rare and never resulted in any disability, death or were life-threatening.

CONCLUSION

In over-70 patients with systolic CHF, chronic atrial fibrillation does not limit the possibility of testing beta-blocker therapy. Carvedilol was equally tolerated and safe in patients with atrial fibrillation and sinus rhythm.

Left ventricular diastolic function improvement by carvedilol therapy in advanced heart failure

Carvedilol treatment in chronic heart failure (CHF) patients has been demonstrated to reduce mortality by improving cardiac systolic function and reducing left ventricular adverse remodeling. However, the effects of the drug on left ventricular (LV) filling are less studied. In this study we evaluated early and long-term diastolic cardiac modifications by an echo-Doppler method during carvedilol therapy in patients with advanced CHF and pseudonormal or restrictive filling pattern. We studied 58 patients with severe but stable CHF (39 in class NYHA III and 19 in IV) having systolic and diastolic dysfunction caused by idiopathic or ischemic cardiomyopathy. Thirty-two patients were randomized to receive previous treatment plus carvedilol (group 1) and 26 continued standard therapy (group 2). In all subjects we evaluated LV volumes, LV mass, LV ejection fraction (EF), and the following transmitral filling parameters: early wave (E), atrial wave (A), E/A ratio, deceleration time (DT), and isovolumetric releasing time (IVRT). After 4 months of therapy, the carvedilol group showed a significant increase of A wave (P < 0.001), DT (P < 0.0001), IVRT (P < 0.0001), and a significant reduction of E/A ratio (P < 0.0005) with respect to group 2. Further improvement was observed at 12 months (A P < 0.0005; DT P < 0.00002; IVRT P < 0.000004; E/A P < 0.0008), although an E wave reduction was observed in group 1 with respect to controls (P < 0.001). Moreover, after 1 year of follow-up a reduction of systolic volume (P < 0.001) and pulmonary pressure (P < 0.0001) and consequent increase of EF (P < 0.001) was observed in the carvedilol group. Carvedilol treatment improved diastolic function in CHF with severe diastolic and systolic impairment at early time, converting a restrictive or pseudonormal filling pattern into an altered pattern. These changes remained significant after 1 year of therapy together with improvement in systolic function.

The impact of baseline HR and BP on the tolerability of carvedilol in the elderly: the COLA (Carvedilol Open Label Assessment) II Study

BACKGROUND

The COLA (Carvedilol Open Label Assessment) II Study prospectively evaluated the tolerability of carvedilol in 1030 patients >70 years of age with chronic heart failure (CHF). Tolerability, defined as patients receiving > or =3 months of carvedilol and achieving a maintenance dosage > or =12.5 mg/day, was 80%. In a multivariate analysis, advanced age, low DBP, left ventricular ejection fraction, obstructive airways disease, and a presence of diabetes mellitus were predictors of tolerability. The aim of this analysis was to evaluate further the relationship between baseline HR, SBP, DBP and tolerability in COLA II.

METHODS

Baseline HR, SBP and DBP data were available in 1009 patients (98%). These data were analyzed as both continuous and categorical variables. For the latter analysis, the following categories were created: HR <70, 70 < or = HR <90, HR > or =90 bpm; SBP <120, 120 < or = SBP <160, SBP > or =160 mm Hg; DBP <70, 70 < or = DBP <90, DBP > or =90 mm Hg.

RESULTS

Baseline HR did not differ between patients who tolerated carvedilol (T) and those who did not (non-T) [81 +/- 16 vs 79 +/- 16 bpm]. However, SBP and DBP were significantly lower in the non-T versus the T group (131 +/- 20 vs 139 +/- 22 mm Hg for SBP [p < 0.001] and 77 +/- 11 vs 81 +/- 12 mm Hg for DBP [p < 0.001]). Seventy-four percent of patients in the lowest category for baseline HR (<70 bpm tolerated carvedilol versus 82% and 79% of those in the higher categories (p = not significant). Seventy percent of patients in the lowest category of baseline SBP (<120 mm Hg) tolerated carvedilol versus 80% and 89% of those in the upper categories (p < 0.001). Similarly, 73% of patients in the lowest category for DBP (<70 mm Hg) tolerated carvedilol versus 78% and 87% of those in the upper categories (p < 0.005).

CONCLUSIONS

Carvedilol is generally well tolerated by elderly patients with CHF, even in those with low baseline BP or HR. However, a low baseline SBP or DBP does identify patients who are less likely to tolerate the drug. Baseline HR does not appear to significantly affect tolerability in this population.

Impact of a standardized titration protocol with carvedilol in heart failure: safety, tolerability, and efficacy-a report from the GESICA registry

Grupo de Estudio de la Sobrevida en la Insuficiencia Cardiaca en Argentina (GESICA) studied whether a standardized protocol for the initiation and titration of the beta-blocker carvedilol in a multicenter, open-label program would optimize beta-blocker use in heart failure (HF) patients. The program included: (1) the carvedilol initiation and titration period, and (2) long-term follow-up at 6 and 12 months. Of 1299 patients in the registry, 504 were excluded due to current therapy; of the remaining 795 eligible patients, 293 were excluded due to contraindications. Of the included patients with follow-up data (n = 316), 93.3% tolerated carvedilol initiation and 47.7% of the patients reached the target dose of 50 mg/day for a mean dose of 39 mg/day. Rates were comparable in the elderly (n = 83), of which 53% achieved a target dose for a mean dose of 43.08 mg/day. This protocol improved therapy rates and achieved target doses quickly (average of 4 visits). Concomitant medications did not have to be adjusted and there were low withdrawal rates (10%) and hospital admissions (7.2%) for HF. Patients were able to maintain carvedilol therapy at 6 and 12 months. These results indicate that a standardized titration protocol, as used in GESICA, for the initiation and titration of beta-blockers is well tolerated and may improve beta-blocker use in carefully selected heart failure patients.

Contractile responses to selective phosphodiesterase inhibitors following chronic beta-adrenoreceptor activation

Contractile responses to phosphodiesterase (PDE) inhibitors are attenuated in heart failure, an effect limiting the clinical value of these agents. In this study, we sought to determine whether abnormalities in the beta-adrenoreceptor (beta-AR)-cyclic adenosine monophosphate (cAMP) signal transduction are sufficient to account for downregulation of PDE inhibitor-induced inotropic responses following chronic sympathetic activation. Sustained beta-AR activation produced by administration of isoproterenol (ISO) (50 microg kg(-1) day(-1) i.p. for 1 month) to rats resulted in cardiac hypertrophy, but did not affect baseline cardiac systolic function, as assessed in vivo by echocardiography and ex vivo under controlled loading conditions and heart rate (left ventricular systolic pressure-volume and stress-strain relations). Moreover, chronic ISO administration did not alter the baseline myocardial norepinephrine release or inotropic responses to incremental concentrations of Ca(2+) in isolated, perfused heart preparations. However, left ventricular contractile responses to ISO, the PDE III inhibitor amrinone, and the PDE IV inhibitor rolipram were attenuated following chronic beta-AR activation. Myocardial cAMP concentrations after stimulation with amrinone and rolipram were similar in ISO-treated and control rats. However, in ISO-treated rats, a marked decrease in contractile responsiveness to the cell-permeable, PDE-resistant cAMP analogue, 8-bromoadenosine cAMP, was noted. In conclusion, these data suggest that in cardiac disease, sustained beta-AR activation, without producing ventricular systolic dysfunction or enhanced myocardial norepinephrine release, is sufficient to account for the downregulation of contractile responses to PDE inhibitors. This effect appears to be largely mediated through abnormalities in signal transduction between cAMP and Ca(2+)-induced Ca(2+) release.

Out-patient management of chronic heart failure

Chronic heart failure is a clinical syndrome associated with an ominous long-term prognosis and major economic consequences for Western societies. In recent years, considerable progress has been made in the pharmacological management of heart failure, and several treatments have been confirmed to confer survival and symptomatic benefits. However, pharmaceuticals remain underutilised, and the combination of several different drugs present challenges for their optimal prescription, requiring a thorough knowledge of potential side effects and complex interactions. This article reviews in detail the evidence pertaining to the out-patient pharmacological management of chronic heart failure, and offers recommendations on the use of various drugs in complex clinical conditions, or in areas of ongoing controversy.

Beta-blocker therapy in patients with heart failure in the urban setting: moving beyond clinical trials

BACKGROUND

Despite their known benefits, beta-blockers (BBL) are not yet widely prescribed for heart failure, especially in the primary care setting. We wanted to identify patient characteristics that could guide primary care physicians in deciding whether they or a cardiologist should initiate BBL. A second objective was to determine the tolerability of BBL in clinical practice.

METHODS

A retrospective chart review was conducted on a consecutive series of 551 patients with systolic dysfunction referred to a heart failure clinic in an urban public hospital. Patient responses to BBL were stratified into three categories: favorable (improvement of left ventricular ejection fraction by serial echocardiography), unfavorable (development of decompensated heart failure), or neither. Tolerability of BBL was assessed by the need to permanently discontinue BBL.

RESULTS

Of 551 patients, 363 (66%) tolerated BBL. Among patients who had BBL initiated in the clinic, 48 had a favorable response, 34 had an unfavorable response, and 57 had neither a favorable or unfavorable response, as defined. A lower systolic blood pressure and higher diuretic dose were associated with development of decompensated heart failure as compared to improvement of ejection fraction.

CONCLUSIONS

A majority of patients with heart failure in an urban public hospital can tolerate BBL. Easily measurable characteristics such as lower systolic blood pressure and higher diuretic dose may assist primary care physicians in triaging patients for referral to cardiologists for beta-blocker initiation.

[Prediction of intolerance to beta blocker therapy in chronic heart failure patients using BNP]

Beta-blocker therapy is actually recommended as first line therapy for systolic heart failure. However, beta-blocker have a low prescription rate comparatively to ACEI. Beta-blocker potential side effects as bradycardia, hypotension and especially acute decompensation could explain this under prescription. Clinical data could easily identify high-risk patients for hypotension or bradycardia but not high-risk patients for induced decompensation linked to beta-blocker therapy. BNP could identify these patients with a high sensitivity. Patients with BNP above 1000 pg/ml had a 40% risk of acute decompensation after introduction or increase of beta-blocker therapy. As a conclusion, clinicians must be very cautious for introducing or increasing Carvedilol therapy in patients with high BNP levels.

Therapeutic Update: Non-Selective Beta- and Alpha-Adrenergic Blockade in Patients With Coexistent Chronic Obstructive Pulmonary Disease and Chronic Heart Failure

Patients with chronic heart failure (CHF) have a resting restrictive ventilatory defect. Any type of exercise requires patients with CHF to markedly increase their minute ventilation. Patients with chronic obstructive pulmonary disease (COPD) have airflow obstruction that leads to dynamic lung hyperinflation and reduced ventilatory response to exercise. Because exercise is associated with abnormally high minute ventilation in patients with CHF and with a limited minute ventilation increase in patients with COPD, functional capacity is severely impaired in patients with coexistent CHF and COPD. Optimal treatment of both conditions is a prerequisite to maximally improve functional capacity in patients with CHF and COPD. Unfortunately, beta-adrenergic blockade, the current cornerstone of CHF therapy, is frequently omitted in patients with CHF and COPD for fear of inducing bronchoconstriction. Furthermore, when prescribed, beta-adrenergic blockade is often attempted with a moderate dose of metoprolol tartrate, a beta-1-blocker that results in lesser clinical benefits than combined non-selective beta-blockade with carvedilol at the maximally recommended dose. Recent experience indicates that combined non-selective beta- and alpha-blockade with carvedilol is well tolerated in patients with COPD who do not have reversible airway obstruction. Alpha-adrenergic blockade may promote mild bronchodilation that offsets non-selective beta blockade-induced bronchoconstriction in patients with obstructive airway disease.

?-Adrenoceptor Blockers as Agonists: Coupling of ?2-Adrenoceptors to Multiple G-Proteins in the Failing Human Heart

Beta blockers have been shown in clinical trials to improve cardiac function and reduce mortality of heart failure patients. However, these agents require careful titration since they can produce an initial decrease in cardiac output. The authors have recently shown that beta blockers, including some used clinically, can directly depress contraction of myocardium from the failing (but not nonfailing) human heart. This occurs on single ventricular myocytes and is therefore completely independent of any inhibition of endogenous catecholamines. The effect appears to be mediated primarily by the beta2-adrenoceptor (AR) and is dependent on the inhibitory guanine nucleotide binding protein, Gi. Using a transgenic mouse model, as well as adenoviral vectors to overexpress Gi or the human beta2AR in adult myocytes of various species, the authors demonstrate that agents that are blockers for bAR/Gs coupling can be agonists at a beta2AR/Gi-coupled form of the receptor. The negative effect of beta blockers could contribute to the initial cardiodepression that is observed when introducing these agents in heart failure patients. However, in the long term, beta2AR/Gi coupling may enhance the ability of beta blockers to protect and improve the function of the failing heart.

Carvedilol: a review of its use in chronic heart failure

Carvedilol (Dilatrend) blocks beta(1)-, beta(2)- and alpha(1)-adrenoceptors, and has antioxidant and antiproliferative effects. Carvedilol improved left ventricular ejection fraction (LVEF) in patients with chronic heart failure (CHF) in numerous studies. Moreover, significantly greater increases from baseline in LVEF were seen with carvedilol than with metoprolol in a double-blind, randomised study and in a meta-analysis. Carvedilol also reversed or attenuated left ventricular remodelling in patients with CHF and in those with left ventricular dysfunction after acute myocardial infarction (MI). Combined analysis of studies in the US Carvedilol Heart Failure Trials Program (patients had varying severities of CHF; n = 1094) revealed that mortality was significantly lower in carvedilol than in placebo recipients. In addition, the risk of hospitalisation for any cardiovascular cause was significantly lower with carvedilol than with placebo. Mortality was significantly lower with carvedilol than with metoprolol in patients with mild to severe CHF in the Carvedilol Or Metoprolol European Trial (COMET) [n = 3029]. The Carvedilol Prospective Randomised Cumulative Survival (COPERNICUS) trial (n = 2289) demonstrated that compared with placebo, carvedilol was associated with significant reductions in all-cause mortality and the combined endpoint of death or hospitalisation for any reason in severe CHF. All-cause mortality was reduced in patients who received carvedilol in addition to conventional therapy compared with those who received placebo plus conventional therapy in the Carvedilol Post-Infarct Survival Control in LV Dysfunction (CAPRICORN) trial (enrolling 1959 patients with left ventricular dysfunction following acute MI). Carvedilol was generally well tolerated in patients with CHF. Adverse events associated with the alpha- and beta-blocking effects of the drug occurred more commonly with carvedilol than with placebo, whereas placebo recipients were more likely to experience worsening heart failure. In conclusion, carvedilol blocks beta(1)-, beta(2)- and alpha(1)-adrenoceptors and has a unique pharmacological profile. It is thought that additional properties of carvedilol (e.g. antioxidant and antiproliferative effects) contribute to its beneficial effects in CHF. Carvedilol improves ventricular function and reduces mortality and morbidity in patients with mild to severe CHF, and should be considered a standard treatment option in this setting. Administering carvedilol in addition to conventional therapy reduces mortality and attenuates myocardial remodelling in patients with left ventricular dysfunction following acute MI. Moreover, mortality was significantly lower with carvedilol than with metoprolol in patients with mild to severe CHF, suggesting that carvedilol may be the preferred beta-blocker.

PDE3 inhibition in dilated cardiomyopathy: reasons to reconsider

BACKGROUND

PDE3 cyclic nucleotide phosphodiesterases have important roles in regulating cAMP- and cGMP-mediated signaling. Drugs that inhibit these enzymes raise cAMP and cGMP content in cardiac and vascular smooth muscle and increase the phosphorylation of proteins by cAMP- and cGMP-dependent protein kinases (PK-A and PK-G), thereby eliciting inotropic and vasodilatory responses.

METHODS

Although these actions are beneficial acutely in patients with dilated cardiomyopathy, long-term use of these agents was shown in several clinical trials to increase mortality. Several new clinical studies, however, suggest PDE3 inhibitors may be safe and effective when used in conjunction with beta-adrenergic receptor antagonists, whereas new studies at the cellular and molecular levels indicate that there are several isoforms of these enzymes in cardiac and vascular myocytes that are likely to regulate cAMP content in different intracellular compartments.

CONCLUSIONS

Both sets of observations suggest that PDE3 inhibition may be refined to allow more selective effects on phosphorylation of PK-A substrates, possibly allowing the beneficial effects of PDE3 inhibition to be separated from the adverse long-term consequences of their use.

Beta-blocker therapy and severe heart failure: myth or reality?

The medical management of heart failure has undergone remarkable progress in the past 10 years. The paradigm shift is toward long-term reparative strategies that help in altering the biologic properties of the failing heart. Together with angiotensin-converting enzyme inhibitors, beta blockers have emerged as standard therapy for heart failure, especially for patients with mild to moderate heart failure. Since most of the clinical trials demonstrating the benefits of betablockers have been done in patients with mild to moderate heart failure, some controversy exists about the utility of beta-blocking agents in patients with advanced heart failure. This review will summarize the rationale and the use of beta blockers, a very challenging therapeutic strategy, in patients with severe heart failure.

Relation between heart rate, heart rhythm, and reverse left ventricular remodelling in response to carvedilol in patients with chronic heart failure: a single centre, observational study

OBJECTIVE

To determine whether the process of reverse left ventricular remodelling in response to carvedilol is dependent on baseline heart rate (BHR), heart rhythm, or heart rate reduction (HRR) in response to carvedilol.

DESIGN

Retrospective analysis of serial echocardiograms in 257 patients with chronic systolic heart failure at baseline and at 12-18 months after starting carvedilol. Reverse left ventricular remodelling was determined by changes in left ventricular end diastolic dimension (LVEDD), end systolic dimension (LVESD), and fractional shortening (LVFS).

SETTING

Heart failure clinic within a university teaching hospital.

MAIN OUTCOME MEASURES

Changes in LVEDD, LVESD, and LVFS.

RESULTS

LVEDD and LVESD decreased by 2.6 (0.4) mm and 4.9 (0.5) mm, respectively (mean (SEM)), and LVFS increased by 4.3 (0.5)% (all p < 0.0001 v baseline). Simple regression revealed no significant relation between BHR or HRR and the changes in LVEDD, LVESD, or LVFS. Stratification of patients into high and low BHR groups (above and below the mean) or according to the baseline heart rhythm (sinus rhythm v atrial fibrillation) showed no differences between groups in the extent of reverse left ventricular remodelling. Improvements in left ventricular function and dimensions were associated with significant improvements in New York Heart Association functional class.

CONCLUSIONS

The benefits of carvedilol in terms of reverse left ventricular remodelling and symptomatic improvement in patients with chronic heart failure are independent of BHR, heart rhythm, and the HRR that occurs in response to carvedilol.

Tolerability of carvedilol in patients with heart failure and concomitant chronic obstructive pulmonary disease or asthma

BACKGROUND

A substantial proportion of the population with congestive heart failure (CHF) has concomitant airway disease. Little information exists on the tolerability of carvedilol in patients with chronic obstructive pulmonary disease (COPD). In this study, we assessed the tolerability and efficacy of carvedilol in patients with CHF and concomitant COPD or asthma.

METHODS

Between 1996 and 2000, a total of 487 patients began receiving open-label carvedilol. Forty-three (9%) had COPD (n = 31) or asthma (n = 12). Spirometry supported clinical diagnosis in all, and full pulmonary function testing supported diagnosis in 71%. Sixty percent began carvedilol therapy in the hospital and underwent measurement of peak expiratory flow rates (PEFR) before and after dosing.

RESULTS

In patients with COPD, mean forced expiratory volume in one second (FEV(1)) was 62% +/- 13% predicted, reversibility was 4% +/- 4% with bronchodilators, and FEV(1)/FVC was 62% +/- 8%. Mean PEFR was 325 +/- 115 liter/min before the dose and increased by 17% 2 hours after the carvedilol dose (p = 0.04). In patients with asthma, mean FEV(1) was 80% +/- 17% predicted, reversibility was 13% +/- 7%, and FEV(1)/FVC was 74% +/- 11%. Mean PEFR was 407 +/- 161 liter/min before the dose with no significant change 2 hours after the dose. Carvedilol was introduced safely in 84% of patients with COPD, with only 1 patient withdrawn from therapy for wheezing. In contrast, only 50% of patients with asthma tolerated carvedilol. Survival at 2.5 years was 72%. In survivors, left ventricular end-diastolic diameter decreased from 76 +/- 11 mm to 72 +/- 14 mm (p = 0.01), left ventricular end-systolic diameter decreased from 65 +/- 13 mm to 60 +/- 15 mm (p = 0.01), and fractional shortening increased from 14% +/- 7% to 17% +/- 7% (p = 0.05) at 12 months.

CONCLUSIONS

Patients with CHF and COPD tolerated carvedilol well with no significant reversible airflow limitation, but patients with CHF and asthma tolerated carvedilol poorly. The effect of carvedilol on left ventricular dimensions and function in patients with concomitant airway diseases was similar to that seen in our general group of patients. Asthma remains a contraindication to beta-blockade.

Effects of carvedilol on left ventricular remodeling and systolic function in elderly patients with heart failure

BACKGROUND

Recent studies have shown that carvedilol therapy in patients with heart failure improves clinical outcome and survival, however, the effects of such treatment on left cardiac morphology and function in elderly patients with severe heart failure has not been widely studied.

AIM

The purpose of this study was to establish the effect of carvedilol at short- and long-term on left ventricular size and performance with mono- and two-dimensional echocardiography, in subjects with dilated cardiomyopathy, NYHA III functional class, low LV ejection fraction (EF < 35%) and mean age of > 70 years.

METHODS

We studied 48 patients, previously randomized to treatment with either carvedilol or placebo, and we performed echocardiographic evaluation at the start, and after 3 and 12 months. Left ventricular diameters, LV mass and fractional shortening were calculated by Deveraux formula; left ventricular volumes and ejection fraction were measured by area-length formula; pulmonary pressure was calculated by tricuspid reflow.

RESULTS

After 3 months, only LV end-diastolic diameter was lower in the carvedilol group compared to the placebo group. Nevertheless, after 12 months, patients on carvedilol treatment showed a LV geometric and functional improvement compared to placebo. We found significant differences in: diastolic (P < 0.01) and systolic diameters (P < 0.001); on LV mass (P < 0.002); on LV systolic volume (P < 0.03); and on LV ejection fraction (P<0.01). Pulmonary pressure was also reduced in beta-blocker subjects (P < 0.001).

CONCLUSIONS

Carvedilol therapy for 12 months reduced LV diameters and volumes. Thus, improving cardiac remodeling and LV systolic function in elderly patients with severe heart failure. Several months of therapy are required for these favorable effects to occur, as these changes do not occur in the short term.

Inhibitors of cyclic nucleotide phosphodiesterase PDE3 as adjunct therapy for dilated cardiomyopathy

PDE3 cyclic nucleotide phosphodiesterases are important in cyclic AMP (cAMP) and possibly cyclic GMP-mediated signalling in cardiac and vascular smooth muscle myocytes. Drugs that inhibit these enzymes have inotropic and vasodilatory actions that have proven useful in the short-term treatment of contractile failure and pulmonary hypertension in dilated cardiomyopathy (both ischaemic and idiopathic). With long-term usage, however, these drugs appear to increase mortality in treated patients through an as yet undetermined mechanism that is in some way attributable to an increase in intracellular cAMP content in cardiac myocytes. Several recent clinical trials have raised the possibility that these drugs may be used to advantage in dilated cardiomyopathy when they are administered in combination with beta-adrenoceptor antagonists, which act to lower intracellular cAMP content. In this review, the relevant basic and clinical data are examined and the possible justification for the combination of two therapies with seemingly opposite effects on intracellular cAMP content is considered.

Beta-blocker therapy influences the hemodynamic response to inotropic agents in patients with heart failure: a randomized comparison of dobutamine and enoximone before and after chronic treatment with metoprolol or carvedilol

OBJECTIVE

We compared the hemodynamic effects of dobutamine and enoximone administration before and after long-term beta-blocker therapy with metoprolol or carvedilol in patients with chronic heart failure (HF).

BACKGROUND

Patients with HF on beta-blocker therapy may need hemodynamic support with inotropic agents, and the hemodynamic response may be influenced by both the inotropic agent and the beta-blocker used.

METHODS

The hemodynamic effects of dobutamine (5 to 20 microg/kg/min intravenously) and enoximone (0.5 to 2 mg/kg intravenously) were assessed by pulmonary artery catheterization in 29 patients with chronic HF before and after 9 to 12 months of treatment with metoprolol or carvedilol at standard target maintenance oral doses. Hemodynamic studies were performed after >/=12 h of wash-out from all cardiovascular medications, except the beta-blockers that were administered 3 h before the second study.

RESULTS

Compared with before beta-blocker therapy, metoprolol treatment decreased the magnitude of mean pulmonary artery pressure (PAP) and pulmonary wedge pressure (PWP) decline during dobutamine infusion and increased the cardiac index (CI) and stroke volume index (SVI) response to enoximone administration, without any effect on other hemodynamic parameters. Carvedilol treatment abolished the increase in heart rate, SVI, and CI and caused a rise, rather than a decline, in PAP, PWP, systemic vascular resistance, and pulmonary vascular resistance during dobutamine infusion. The hemodynamic response to enoximone, however, was maintained or enhanced in the presence of carvedilol.

CONCLUSIONS

In contrast with its effects on enoximone, carvedilol and, to a lesser extent, metoprolol treatment may significantly inhibit the favorable hemodynamic response to dobutamine. No such beta-blocker-related attenuation of hemodynamic effects occurs with enoximone.

Myocardial contractile reserve under low doses of dobutamine and improvement of left ventricular ejection fraction with treatment by carvedilol

To examine the ability of myocardial contractile reserve (MCR) assessment to predict the improvement of left ventricular ejection fraction with treatment by carvedilol, a prospective study was undertaken in 85 patients with chronic heart failure and left ventricular ejection fraction < 45%. Low dose dobutamine echocardiography (DSE), a 6-min walk test and measured brain natriuretic peptide (BNP) were assessed in all the patients. Patients were separated into two groups. Group A were patients without any myocardial reserve and group B patients with a myocardial contractile reserve defined as an increment of more than 20% of the resting left ventricular ejection fraction during dobutamine infusion. The two groups differed for percentage of ischemic cardiomyopathy (67.8 in group A vs. 29.7% in group B P = 0.028), 6-min walk test performance (respectively, 343 vs. 415 meters P < 0.05) and BNP plasma levels (respectively, 184.5 vs. 70.1 P < 0.02) but not for left ventricular ejection fraction or NYHA class. During DSE, MCR and heart rate variation was higher in group B than in group A. At the end of the follow up, LVEF increased and NYHA class decreased in group B but not in group A. In multivariate analysis the existence of MCR could predict the improvement of LVEF with treatment by carvedilol. In our study, studying MCR could help to predict patients who will improve their LVEF with carvedilol prior to the administration of the treatment.

Low-dose amiodarone for patients with advanced heart failure who are intolerant of beta-blockers

The tolerability and effectiveness of amiodarone in patients with advanced heart failure (HF) who are intolerant of beta-blockers was investigated in 22 patients (13 with and 9 without 180+/-26 mg/day of amiodarone). Heart rate (HR), blood pressure (BP), left ventricular diastolic dimension and fractional shortening (FS) using echocardiography, plasma atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and norepinephrine concentrations were determined at baseline and after 1 and 3 months of therapy. Although 9 patients tolerated amiodarone without any signs of HF, it was exacerbated in 4 patients. In 10 patients taking amiodarone who could be followed medically for 3 months, HR decreased after 1 month and remained unchanged until after 3 months (81+/-12 vs 65+/-7 vs 65+/-7beats/min), accompanied by decreased concentration of BNP (688+/-485 vs 392+/-203 vs 261+/-192pg/ml). FS increased significantly only after 3 months (0.12+/-0.05 vs 0.14+/-0.05 vs 0.16+/-0.04). Amiodarone may be used in patients with advanced HF who are intolerant of beta-blockers.

Tolerability of beta-blocker initiation and titration in the Metoprolol CR/XL Randomized Intervention Trial in Congestive Heart Failure (MERIT-HF)

BACKGROUND

beta-Blockade improves survival when administered over a long period of time to patients with heart failure. However, the time course of any possible deterioration during the titration phase has not been reported.

METHODS AND RESULTS

We looked at evidence of clinical deterioration in the Metoprolol CR/XL Randomized Intervention Trial in Congestive Heart Failure (MERIT-HF) by analyzing events and symptoms during the first 90 days. During titration, the Kaplan-Meier curves for the combined end point of all-cause mortality/all-cause hospitalization were similar in all patients randomized, with no significant difference in favor of placebo at any visit or in any of the analyzed subgroups (New York Heart Association class II, III/IV, or III/IV with ejection fraction <0.25, heart rate less-than-or-equal 76 bpm, and systolic blood pressure less-than-or-equal 120 mm Hg). The curves started to diverge in favor of beta-blockade after 60 days. Low heart rate was the main factor that limited titration. In New York Heart Association class III/IV, 5.9% of the patients receiving placebo discontinued study medicine during the first 90 days compared with 8.1% of those receiving metoprolol CR/XL (P=0.037 unadjusted, P=NS adjusted); corresponding figures in those with New York Heart Association class III/IV and ejection fraction <0.25 were 7.1% and 8.0% (P=NS). From day 90 until the end of the study, more patients in the placebo group discontinued study medicine in all subgroups. There was no change in diuretic or ACE inhibitor dosing with beta-blocker titration. Most patients reported no change in symptoms of breathlessness or fatigue during the titration phase.

CONCLUSIONS

When carefully titrated, metoprolol CR/XL can be given safely to the overwhelming majority of patients with stable mild to moderate heart failure, with minimal side effects or deterioration.

Effect of vasodilatory beta-adrenoceptor blockers on cardiovascular haemodynamics in anaesthetized rats

1. The effect of vasodilatory beta-adrenoceptor blockers on regional blood flow in the major organs of anaesthetized rats was investigated using radioactive microspheres. The administration of propranolol and saline was used as a control. 2. Intravenous injections of carvedilol (2 mg/rat), celiprolol (20 mg/rat) and bopindolol (1 mg/rat) equally decreased systemic blood pressure (SBP) by approximately 20 mmHg, whereas propranolol (1 mg/rat) decreased SBP only slightly but not significantly. 3. Heart rate was significantly decreased by carvedilol, celiprolol, bopindolol and propranolol. 4. Coronary blood flow was markedly increased by carvedilol, but not by the other three drugs. 5. Cardiac output tended to decrease following the administration of all four drugs. 6. Total peripheral vascular resistance was not significantly affected by carvedilol, celiprolol and bopindolol, but was markedly increased following propranolol. 7. Renal blood flow was markedly increased by carvedilol. 8. Blood flow in the brown fat was markedly increased by carvedilol and bopindolol, but not by celiprolol and propranolol. 9. These findings indicate that the newer vasodilatory beta-blockers, such as carvedilol and bopindolol, have a beneficial effect on the regional circulation in contrast with the classical beta-blocker propranolol. 10. The regional haemodynamic effects observed in the present study following intravenous injection of the beta-blockers may help explain the clinical experience that vasodilatory beta-blockers increase insulin sensitivity and decrease mortality in patients with congestive heart failure.

Carvedilol: molecular and cellular basis for its multifaceted therapeutic potential

Carvedilol is a unique cardiovascular drug of multifaceted therapeutic potential. Its major molecular targets recognized to date are membrane adrenoceptors (beta 1, beta 2, and alpha 1), reactive oxygen species, and ion channels (K+ and Ca2+). Carvedilol provides prominent hemodynamic benefits mainly through a balanced adrenoceptor blockade, which causes a reduction in cardiac work in association with peripheral vasodilation. This drug assures remarkable cardiovascular protection through its antiproliferative/atherogenic, antiischemic, antihypertrophic, and antiarrhythmic actions. These actions are a consequence of its potent antioxidant effects, amelioration of glucose/lipid metabolism, modulation of neurohumoral factors, and modulation of cardiac electrophysiologic properties. The usefulness of carvedilol in the treatment of hypertension, ischemic heart disease, and congestive heart failure is based on a combination of hemodynamic benefits and cardiovascular protection.

Predictors of medical events and of their competitive interactions in the Cardiac Insufficiency Bisoprolol Study 2 (CIBIS-2)

AIMS

Predictive factors for medical events and interactions between events were not reported in the Cardiac Insufficiency Bisoprolol Study 2 (CIBIS-2). We examined the interactions among death, permanent treatment withdrawals, nonlethal cardiovascular hospitalizations and their own occurrence in a given patient, the treatment received, and baseline variables during CIBIS-2.

METHODS AND RESULTS

A Cox model for censored data was used to analyze the relations among baseline variables, medical events, and their interactions with treatment. We used competitive risk analysis to examine the interactions between successive events in a given patient during follow-up. No baseline variable predicted the reduction of mortality with bisoprolol. Withdrawal from bisoprolol therapy was more frequent in patients whose baseline heart rate was in the lower tertile of the distribution (P =.0002) but otherwise was not different between patients randomized to bisoprolol and to placebo. Event history analysis revealed that bisoprolol reduced mortality (P =.0006) and hospitalizations for nonlethal cardiovascular events (P =.003) in patients in whom treatment was not permanently withdrawn. Analysis of survival curves in patients who permanently discontinued treatment showed that bisoprolol did not reduce mortality compared with placebo in this population (relative risk 1.03, 95% CI 0.67-1.59; P =.88). Recurrent nonlethal events were reduced by bisoprolol.

CONCLUSION

In CIBIS-2, medical events were significantly influenced by treatment withdrawal. Patients who derive benefit from bisoprolol therapy are those in whom treatment is not permanently withdrawn.

Echo-Doppler mitral flow monitoring: an operative tool to evaluate day-to-day tolerance to and effectiveness of beta-adrenergic blocking agent therapy in patients with chronic heart failure

OBJECTIVES

The goals of this study were: 1) to assess the predictive value of baseline mitral flow pattern (MFP) and its changes after loading manipulations as regards tolerance to and effectiveness of beta-adrenergic blocking agent treatment in patients with chronic heart failure (CHF); and 2) to analyze the prognostic implications of chronic MFP modifications after beta-blocker treatment.

BACKGROUND

In patients with CHF, carvedilol therapy induces clinical and hemodynamic improvements. Individual management, clinical effectiveness and prognostic implications, however, remain unclear. The MFP changes induced by loading manipulations provide independent prognostic information.

METHODS

Echo-Doppler was performed at baseline and after loading manipulations in 116 consecutive patients with CHF (left ventricular ejection fraction: 25 +/- 7%); 54 patients with a baseline restrictive MFP were given nitroprusside infusion; 62 patients with a baseline nonrestrictive MFP performed passive leg lifting. According to changes in MFP, we identified four groups: 17 with irreversible restrictive MFP (Irr-rMFP), 37 with reversible restrictive MFP (Rev-rMFP), 12 with unstable nonrestrictive MFP (Un-nrMFP) and 50 with stable nonrestrictive MFP (Sta-nrMFP). Carvedilol therapy (44 +/- 27 mg) was administered blind to results of loading maneuvers. After six months, MFP was reassessed and patients reclassified according to chronic MFP changes. During follow-up, tolerance to and effectiveness of treatment and major cardiac events (death, readmission and urgent transplantation) were considered.

RESULTS

Changes of MFP after loading manipulations were more accurate than baseline MFP in predicting both tolerance to (p < 0.01) and effectiveness of (p < 0.05) carvedilol. After 26 +/- 14 months of follow-up, cardiac events had occurred in 23/102 patients (23%). The event rate in patients with chronic Irr-rMFP or Un-nrMFP was markedly higher than it was in those with Rev-rMFP or Sta-nrMFP.

CONCLUSIONS

In our patients, tolerance to and effectiveness of carvedilol was predicted better by echo-Doppler MFP changes after loading manipulations than by baseline MFP. Chronic changes of MFP after therapy are strong predictors of major cardiac events.

Canine idiopathic dilated cardiomyopathy. Part II: pathophysiology and therapy

Dilated cardiomyopathy (DCM) in dogs is characterized by ventricular and atrial enlargement, and systolic and diastolic dysfunction, with congestive heart failure (CHF) often developing at some stage. With greater understanding of the impact of neuroendocrine stimulation in heart disease, the understanding of the pathophysiology for CHF has changed considerably. It is no longer considered only to be a simple haemodynamic consequence of pump dysfunction, but is now characterized as a complex clinical syndrome with release of many neurohormones, which are believed to have impact on the progression of disease. This change in our understanding of the pathophysiology of CHF has important therapeutic implications. There are strong indications, although not yet proven, that drugs designed to influence the neuroendocrine activity, such as Angiotensin Converting Enzyme (ACE) inhibitors and beta-receptors antagonists, are efficacious as adjunct therapy of heart failure attributable to DCM in dogs. The benefits of drugs designed to influence the myocardial contractile state (positive inotropes) have not been fully evaluated. However, evidence has emerged in recent years indicating that new types of positive inotropes may be beneficial in dogs with DCM. This review focuses on the neuroendocrine aspects of DCM and their possible therapeutic implications and the place for long-term inotropic support in dogs with DCM.

Polypharmacy of heart failure. Creating a rational pharmacotherapeutic protocol

In the management of chronic heart failure, polypharmacy is common, necessary, and often overlooked. The increasing costs of care, noncompliance, and frequent adverse drug interactions have led to diminishing benefits by simply adding additional drugs to the already complex regimen. This review outlines a rational pharmacotherapeutic protocol based on establishing overall therapeutic goals and confirming treatment targets, tailoring therapy to individual patients by balancing beneficial and adverse drug effects, and paying particular attention to patient education and other nonpharmacologic support.

Optimization of left ventricular function with carvedilol before high-risk cardiac surgery

Patients with severe left ventricular dysfunction and symptomatic heart failure caused by ischemic or valvular heart disease face a high morbidity and mortality risk from cardiac surgery. We present data showing that excellent surgical outcome can be achieved after pre-treatment of such patients with carvedilol.