Regression of left ventricular remodeling in chronic heart failure: Comparative and combined effects of captopril and carvedilol

Left ventricular reverse remodelling and its predictors in non-ischaemic cardiomyopathy

Adverse remodelling following an initial insult is the hallmark of heart failure (HF) development and progression. It is manifested as changes in size, shape, and function of the myocardium. While cardiac remodelling may be compensatory in the short term, further neurohumoral activation and haemodynamic overload drive this deleterious process that is associated with impaired prognosis. However, in some patients, the changes may be reversed. Left ventricular reverse remodelling (LVRR) is characterized as a decrease in chamber volume and normalization of shape associated with improvement in both systolic and diastolic function. LVRR might occur spontaneously or more often in response to therapeutic interventions that either remove the initial stressor or alleviate some of the mechanisms that contribute to further deterioration of the failing heart. Although the process of LVRR in patients with new‐onset HF may take up to 2 years after initiating treatment, there is a significant portion of patients who do not improve despite optimal therapy, which has serious clinical implications when considering treatment escalation towards more aggressive options. On the contrary, in patients that achieve delayed improvement in cardiac function and architecture, waiting might avoid untimely implantable cardioverter‐defibrillator implantation. Therefore, prognostication of successful LVRR based on clinical, imaging, and biomarker predictors is of utmost importance. LVRR has a positive impact on prognosis. However, reverse remodelled hearts continue to have abnormal features. In fact, most of the molecular, cellular, interstitial, and genome expression abnormalities remain and a susceptibility to dysfunction redevelopment under biomechanical stress persists in most patients. Hence, a distinction should be made between reverse remodelling and true myocardial recovery. In this comprehensive review, current evidence on LVRR, its predictors, and implications on prognostication, with a specific focus on HF patients with non‐ischaemic cardiomyopathy, as well as on novel drugs, is presented.

The pyruvate-lactate axis modulates cardiac hypertrophy and heart failure

The metabolic rewiring of cardiomyocytes is a widely accepted hallmark of heart failure (HF). These metabolic changes include a decrease in mitochondrial pyruvate oxidation and an increased export of lactate. We identify the mitochondrial pyruvate carrier (MPC) and the cellular lactate exporter monocarboxylate transporter 4 (MCT4) as pivotal nodes in this metabolic axis. We observed that cardiac assist device-induced myocardial recovery in chronic HF patients was coincident with increased myocardial expression of the MPC. Moreover, the genetic ablation of the MPC in cultured cardiomyocytes and in adult murine hearts was sufficient to induce hypertrophy and HF. Conversely, MPC overexpression attenuated drug-induced hypertrophy in a cell-autonomous manner. We also introduced a novel, highly potent MCT4 inhibitor that mitigated hypertrophy in cultured cardiomyocytes and in mice. Together, we find that alteration of the pyruvate-lactate axis is a fundamental and early feature of cardiac hypertrophy and failure.

Left ventricular reverse remodeling in patients with anterior wall ST-segment elevation acute myocardial infarction treated with primary percutaneous coronary intervention

Introduction

The study aimed to evaluate the prevalence and predictors of left ventricular (LV) reverse remodeling and its impact on long-term prognosis in patients with anterior ST-segment elevation myocardial infarction (STEMI).

Aim

To assess the percentage of reverse remodeling and its prognostic factors in anterior STEMI patients.

Material and methods

This observational study included 40 patients with first ever STEMI of the anterior wall. LV reverse remodeling was defined as the reduction of left ventricular end-systolic volume (ΔLVESV) by ≥ 10% in 3D transthoracic echocardiography (3D-TTE) at 3-month follow-up. 3D-TTE and speckle tracking imaging were performed during index hospitalization, while 3D-TTE and cardiac magnetic resonance (CMR) were performed at 3 months following the procedure. Patients were followed up for a median time of 3.4 years in order to evaluate major adverse cardiovascular events.

Results

Left ventricular reverse remodeling at 3-month follow-up was confirmed in 15 (37.5%) patients. The presence of reverse remodeling was predicted by lower troponin levels (unit OR = 0.86, p = 0.02), lower sum of ST-segment elevations before (unit OR = 0.87, p = 0.03) and after PCI (unit OR = 0.40, p = 0.03), lower maximal ST-segment elevation after PCI (unit OR = 0.01, p = 0.03), lower wall motion score index (unit OR 0.40, p = 0.03) and more negative anterior wall global longitudinal strain (unit OR = 0.88, p = 0.045). Nine MACE were reported in the without reverse remodeling group only. Non-significantly better event-free survival in the reverse remodeling group was demonstrated (log-rank p = 0.07).

Conclusions

Development of reverse modeling in patients with optimal revascularization and tailored pharmacotherapy is relatively high. Further studies are warranted in order to adjudicate its prognostic role for the prediction of adverse events.

Peripheral vasoconstriction induced by β-adrenoceptor blockers: a systematic review and a network meta-analysis

AIM

Peripheral vasoconstriction has long been described as a vascular adverse effect of β-adrenoceptor blockers. Whether β-adrenoceptor blockers should be avoided in patients with peripheral vascular disease depends on pharmacological properties (e.g. preferential binding to β1 -adrenoreceptors or intrinsic sympathomimetic activity). However, this has not been confirmed in experimental studies. We performed a network meta-analysis in order to assess the comparative risk of peripheral vasoconstriction of different β-adrenoceptor blockers.

METHOD

We searched for randomized controlled trials (RCTs) including β-adrenoceptor blockers that were published in core clinical journals in the Pubmed database. All RCTs reporting peripheral vasoconstriction as an adverse effect of β-adrenoceptor blockers and controls were included. Sensitivity analyses were conducted including possibly confounding covariates (latitude, properties of the β-adrenoceptor blockers, e.g. intrinsic sympathomimetic activity, vasodilation, drug indication, drug doses). The protocol and the detailed search strategy are available online (PROSPERO registry CRD42014014374).

RESULTS

Among 2238 records screened, 38 studies including 57 026 patients were selected. Overall, peripheral vasoconstriction was reported in 7% of patients with β-adrenoceptor blockers and 4.6% in the control groups (P < 0.001), with heterogeneity among drugs. Atenolol and propranolol had a significantly higher risk than placebo, whereas pindolol, acebutolol and oxprenolol had not.

CONCLUSION

Our results suggest that β-adrenoceptor blockers have variable propensity to enhance peripheral vasoconstriction and that it is not related to preferential binding to β1 -adrenoceptors. These findings challenge FDA and European recommendations regarding precautions and contra-indications of use of β-adrenoceptor blockers and suggest that β-adrenoceptor blockers with intrinsic sympathomimetic activity could be safely used in patients with peripheral vascular disease.

Use of carvedilol in hypertension: an update

β-blockers are effective antihypertensive agents and, together with diuretics, have been the cornerstone of pioneering studies showing their benefits on cardiovascular morbidity and mortality as a consequence of blood pressure reduction in patients with hypertension. However, evidence from recent meta-analyses have demonstrated no benefit afforded by atenolol compared with placebo in risk of mortality, myocardial infarction, or stroke, and a higher risk of mortality and stroke with atenolol/propranolol compared with other antihypertensive drug classes. Thus, the effect of these agents on cardiovascular morbidity and mortality in hypertensive patients, especially their use in uncomplicated hypertension, has remained largely controversial. However, it is recognized that the clinical studies used in these meta-analyses were mainly based on the older second-generation β-blockers, such as atenolol and metoprolol. Actually, considerable heterogeneity in, eg, pharmacokinetic, pharmacological, and physicochemical properties exists across the different classes of β-blockers, particularly between the second-generation and newer third-generation agents. Carvedilol is a vasodilating noncardioselective third-generation β-blocker, without the negative hemodynamic and metabolic effects of traditional β-blockers, which can be used as a cardioprotective agent. Compared with conventional β-blockers, carvedilol maintains cardiac output, has a reduced prolonged effect on heart rate, and reduces blood pressure by decreasing vascular resistance. Studies have also shown that carvedilol exhibits favorable effects on metabolic parameters, eg, glycemic control, insulin sensitivity, and lipid metabolism, suggesting that it could be considered in the treatment of patients with metabolic syndrome or diabetes. The present report provides an overview of the main clinical studies concerning carvedilol administered as either monotherapy or in combination with another antihypertensive or more frequently a diuretic agent, with particular focus on the additional benefits beyond blood pressure reduction.

β-Adrenergic receptor antagonists ameliorate myocyte T-tubule remodeling following myocardial infarction

β-Adrenergic receptor (AR) blockers provide substantial clinical benefits, including improving overall survival and left ventricular (LV) function following myocardial infarction (MI), though the mechanisms remain incompletely defined. The transverse-tubule (T-tubule) system of ventricular myocytes is an important determinant of cardiac excitation-contraction function. T-tubule remodeling occurs early during LV failure. We hypothesized that β-AR blockers prevent T-tubule remodeling and thereby provide therapeutic benefits. A murine model of MI was utilized to examine the effect of β-AR blockers on T-tubule remodeling following LV MI. We applied the in situ imaging of T-tubule structure from Langendorff-perfused intact hearts with laser scanning confocal microscopy. We found that MI caused remarkable T-tubule remodeling near the infarction border zone and moderate LV remodeling remote from the MI. Metoprolol and carvedilol administered 6 d after MI for 4 wk each increased the T-tubule integrity at the remote and border zones. At the molecular level, both β-AR blockers restored border and remote zone expression of junctophilin-2 (JP-2), which is involved in T-tubule organization and formation of the T-tubule/sarcoplasmic reticulum junctions. In contrast, β-AR blockers had no significant effects on caveolin-3 expression. In summary, our data show that β-AR antagonists can protect against T-tubule remodeling after MI, suggesting a novel therapeutic mechanism of action for this drug class. Preservation of JP-2 expression may contribute to the beneficial effects of metoprolol and carvedilol on T-tubule remodeling.

Progression of Left Ventricular Dysfunction and Remodelling under Optimal Medical Therapy in CHF Patients: Role of Individual Genetic Background

Background. Neurohormonal systems play an important role in chronic heart failure (CHF). Due to interindividual heterogeneity in the benefits of therapy, it may be hypothesized that polymorphisms of neurohormonal systems may affect left ventricular (LV) remodelling and systolic function. We aimed to assess whether genetic background of maximally treated CHF patients predicts variations in LV systolic function and volumes. Methods and Results. We prospectively studied 131 CHF outpatients on optimal treatment for at least six months. Echocardiographic evaluations were performed at baseline and after 12 months. Genotype analysis for ACE I/D, β1adrenergic receptor (AR) Arg389Gly, β2AR Arg16Gly, and β2AR Gln27Glu polymorphisms was performed. No differences in baseline characteristics were detected among subgroups. ACE II was a significant predictor of improvement of LV end-diastolic and end-systolic volume (P = .003 and P = .002, respectively) but not of LV ejection fraction (LVEF); β1AR389 GlyGly was related to improvement of LVEF (P = .02) and LV end-systolic volume (P = .01). The predictive value of polymorphisms remained after adjustment for other clinically significant predictors (P < .05 for all). Conclusions. ACE I/D and β1AR Arg389Gly polymorphisms are independent predictors of reverse remodeling and systolic function recovery in CHF patients under optimal treatment.

Usefulness of left ventricular conic index measured by real-time three-dimensional echocardiography to predict left ventricular remodeling after acute myocardial infarction

Early identification of left ventricular (LV) remodeling after acute myocardial infarction (AMI) is of clinical importance. The predictive value of real-time 3-dimensional echocardiography (RT-3DE) for LV remodeling after AMI is unknown. We prospectively studied 62 patients with AMI who underwent RT-3DE at baseline (72 +/- 5 hours) and 1 month and 6 months after AMI. LV remodeling was defined as a >20% increase from baseline in LV end-diastolic volume (LVEDV) at 6 months. At 6 months, 20 patients (32%) with and 42 (68%) without LV remodeling were identified. Patients with remodeling showed increased LVEDV, from 112.6 +/- 17.2 to 138 +/- 31 ml (p <0.001), and decreased LV ejection fraction (LVEF), from 0.50 +/- 0.07 to 0.44 +/- 0.10 (p <0.01). Changes in LVEDV from baseline to 6-month follow-up were positively correlated with peak creatine kinase-MB, LVEDV, LVEF, wall motion score, deceleration time of E wave, LV sphericity index (LVEDV divided by the volume of a sphere whose diameter is the LV end-diastolic long axis), and LV conic index (LVEDV divided by the volume of a cone whose bottom diameter is the internal diameter of the mitral annulus and height is the LV long axis). LV conic index at baseline was found to be the best predictor of LV remodeling, with a sensitivity and specificity of 100% and 90.9%, respectively, and a cut-off value of >3.87. In conclusion, LV conic index measured by RT-3DE in the early phase after AMI can accurately predict LV remodeling over 6-month follow-up.

Time course of echocardiographic and electrocardiographic parameters in myocardial infarct in rats

In animal models the evaluation of myocardial infarct size in vivo and its relation to the actual lesion found post mortem is still a challenge. The purpose of the current study was to address if the conventional electrocardiogram (ECG) and/or echocardiogram (ECHO) could be used to adequately predict the size of the infarct in rats. Wistar rats were infarcted by left coronary ligation and then ECG, ECHO and histopathology were performed at 1, 7 and 28 days after surgery. Correlation between infarct size by histology and Q wave amplitude in lead L1 was only found when ECGs were performed one day post-surgery. Left ventricular diastolic and systolic dimensions correlated with infarct size by ECHO on day 7 post-infarction. On days 7 and 28 post-infarction, ejection indexes estimated by M-mode also correlated with infarct size. In summary we show that conventional ECG and ECHO methods can be used to estimate infarct size in rats. Our data suggest that the 7-day interval is actually the most accurate for estimation of infarct size by ECHO.

Pharmacological left ventricular reverse remodeling in elderly patients receiving optimal therapy for chronic heart failure

BACKGROUND AND AIMS

In recent years, reversal of established left ventricular (LV) dilatation has been increasingly recognized in middle-aged patients with dilated cardiomyopathy receiving angiotensin-converting enzyme (ACE) inhibitors and/or beta-blockers. We performed this prospective study to evaluate whether optimized therapy for heart failure also induces LV reverse remodeling in older patients.

METHODS

One hundred and twenty-four patients aged >70 years with LV ejection fraction <40% underwent clinical and echocardiographic evaluation at baseline and after 1 year. During the early stage of follow-up, pharmacological therapy was optimized. LV reverse remodeling was defined as a reduction in LV end-diastolic volume >25% from baseline to final evaluation.

RESULTS

LV reverse remodeling was recognized in 32 patients (26%). Compared to the subjects who did not improve LV geometry, those with reverse remodeling had, at baseline, higher arterial blood pressure, lower serum creatinine levels, shorter duration of symptoms of heart failure, more frequently received beta-blocker therapy and had predominantly nonischemic aetiology. The variables associated with the development of reverse remodeling in the multivariate analysis were shorter duration of symptoms of heart failure (Odds ratio: 7.7; CI: 2.5-23.3, p=0.0001) and beta-blocker therapy (Odds ratio: 6.0; CI: 1.6-23.3, p=0.01).

CONCLUSIONS

LV reverse remodeling takes place in elderly as well as in younger heart failure patients. A significant proportion of elderly patients undergoes this favourable process which occurs prevalently in patients receiving beta-blocker therapy with a short history of cardiac disease.

Drugs for left ventricular remodeling in heart failure

Left ventricular (LV) remodeling (ie, enlargement and functional deterioration occurring over time) is among the main mechanisms of progression in heart failure (HF). LV dilatation and dysfunction are major negative prognostic markers in patients with HF. Treatments that are effective in limiting or even reversing this process can be expected to provide clinical benefit. Changes in LV dimensions rather than in ejection fraction should be used to monitor remodeling. Ejection fraction can be influenced by transient loading conditions and by agents that stimulate contractility at the expense of increased oxygen demand, whereas dimensional changes probably reflect structural modifications occurring in the myocardium. The neurohormonal antagonists that have been demonstrated to reduce mortality and morbidity in HF (angiotensin-converting enzyme inhibitors [ACE], beta-blockers, angiotensin receptor blockers, and aldosterone antagonists) are also able to inhibit or reverse remodeling. In reverse remodeling, beta-blockers appear to be superior to the other classes of drugs, with a stronger correlation between dose and effect, but it must be remembered that they have been tested as an addition to background therapy that may include ACE inhibitors. With regard to nonpharmacologic strategies, biventricular pacing is associated with functional improvement and reverse remodeling in patients with advanced HF and electromechanical dyssynchrony, and it recently has been demonstrated to improve survival in a randomized clinical trial.

Carvedilol in chronic heart failure: past, present and future

Large randomized clinical trials of bisoprolol, carvedilol and metoprolol have conclusively demonstrated the efficacy and confirmed safety of β-blockers in patients with chronic heart failure. Recently, the beneficial effects of carvedilol in patients with heart failure soon after an acute myocardial infarction have also been shown. Despite this, β-blockers remain under-prescribed in this condition. This is of particular importance as heart failure is common and increasing in prevalence. In this article, when to start β-blockade and which β-blocker to use is considered. Since carvedilol is the most studied β-blocker in heart failure and has a broad range of activities that extend beyond β-blockade, whether it has possible advantages over other β-blockers is discussed. Also, how the use of β-blockade might evolve with the introduction of device-related therapy in heart failure is considered.

Genetic predictors and remodeling of dilated cardiomyopathy in muscular dystrophy

BACKGROUND

Dystrophin gene mutations cause 2 common muscular dystrophies, Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD). Both are frequently associated with dilated cardiomyopathy (DCM) and premature death. We hypothesized that early diagnosis and treatment of DCM in DMD/BMD patients would lead to ventricular remodeling and that specific dystrophin gene mutations would predict cardiac involvement.

METHODS AND RESULTS

Sixty-nine boys with DMD (n=62) and BMD (n=7) (mean age, 12.9 and 13.7 years, respectively) were referred to our Cardiovascular Genetics Clinic for evaluation, including echocardiography and DNA analysis. Follow-up evaluations were scheduled yearly until the first abnormal echocardiogram indicative of DCM and quarterly thereafter. After the first abnormal echocardiogram, angiotensin-converting enzyme inhibitor or beta-blocker therapy was started. beta-Blockers were added if echocardiography showed no ventricular remodeling in angiotensin-converting enzyme inhibitor-treated patients after 3 months. DCM was diagnosed in 31 subjects (DMD, 27/62, 44%; BMD, 4/7, 57%) (mean age at onset, 15.4+/-2.8 years; range, 10.4 to 21.2 years). All 31 subjects were begun on pharmacological therapy after diagnosis. On follow-up (n=29), 2 subjects (both DMD) showed stable DCM, 8 subjects (all DMD) showed improvement, and 19 subjects (16 DMD; 3 BMD) showed normalization of left ventricular size and function (total improvement, 27/29 [93%]). DNA analysis in 47 cases (68%) revealed a significant association between DCM and exon 12 and 14 to 17 mutations, possible protection against DCM by exon 51 to 52 mutations, and a trend toward significant association between onset of DCM and exon 31 to 42 mutations. Statistical significance was based on nominal probability values.

CONCLUSIONS

Early diagnosis and treatment of DCM may lead to ventricular remodeling in DMD/BMD patients. Specific dystrophin gene mutations appear to be predictive of cardiac involvement, while other mutations may protect against or inhibit development of DCM. Further studies evaluating the impact of early intervention strategies on left ventricular geometry and function in muscular dystrophy patients seem warranted.

Ventricular remodeling in children with left ventricular dysfunction secondary to various cardiomyopathies

The ventricular remodeling that occurs in adults with left ventricular (LV) dysfunction is characterized by a change in LV shape from an ellipse to more of a sphere and is associated with increased functional mitral regurgitation (MR), decreased exercise tolerance, and poor outcome. There are limited data on the occurrence and importance of LV remodeling in children with LV dysfunction. The purposes of this study were to evaluate in children with LV dysfunction (1) LV shape, (2) changes in LV shape as LV function improves, and (3) the relation between LV shape and functional MR. Children with LV dysfunction were identified and compared with controls. Patient demographics, treatment, and outcomes were noted. Echocardiograms were reviewed for LV function and shape (sphericity index). The echos of a subset of children whose LV ejection fractions (LVEFs) increased by >10% over a follow-up of >6 months were analyzed for changes in sphericity, mitral annulus size, and the degree of MR. Twenty-five children with LV dysfunction were compared with 37 age-matched controls. LV remodeling to a more spherical shape was inversely related to LVEF but was not associated with clinical outcome. In a subset of patients (n = 17) whose LVEFs improved, the reversal of remodeling (decrease in sphericity index) was associated with a decrease in MR and mitral annulus size. In conclusion, LV remodeling occurs in children with LV dysfunction. The reversal of this remodeling with a decrease in the degree of MR and the size of the mitral annulus occurs as systolic function improves.

Betablockers in heart failure: Carvedilol Safety Assessment (CASA 2-trial)

BACKGROUND

Betablockers are a cornerstone in the treatment of patients with chronic heart failure (CHF). The purpose of the present study was to assess safety and tolerability of carvedilol in CHF-patients.

METHODS

66 general practitioners, who were supervised by a local cardiologist, enrolled 151 CHF-patients. All patients were on standard therapy with ACE-inhibitors and diuretics. Carvedilol treatment was started with 3.125 mg twice daily and slowly uptitrated in 2-week intervals to 2x25 mg per day. Mean follow-up was 12 weeks.

RESULTS

145 of the 151 patients (96%) finished the study according to protocol, six patients were lost to follow-up (4%). 59 patients (41%) experienced minor and nine (6%) serious adverse events. 68 were under maximal therapy with 50 mg daily, 33 received 25 mg, and 15 12.5 mg. Overall tolerability was good and NYHA-class fell significantly from 2.2 to 1.8 (P<0.001). Mean heart rate decreased from 78 to 69 bpm (P<0.001), mean systolic blood pressure from 137 to 132 mmHg (P<0.001) and mean diastolic blood pressure from 80 to 76 mmHg (P<0.001). Quality of life significantly improved under carvedilol with a reduction in the Minnesota living with heart failure score from 1.28 to 0.88 (P<0.001).

CONCLUSIONS

Carvedilol is well tolerated in CHF-patients treated by general practitioners. Serious adverse events and hospitalisations are rare. Thus, carvedilol is a safe drug in the treatment of CHF-patients and can be easily initiated and managed by the general practitioner.

Effects of carvedilol on left ventricular remodelling in chronic stable heart failure: a cardiovascular magnetic resonance study

BACKGROUND

The ability of beta blockers to improve left ventricular function has been demonstrated, but data on the effects on cardiac remodelling are limited.

OBJECTIVE

To investigate, using cardiovascular magnetic resonance (CMR), the effects of carvedilol on left ventricular remodelling in patients with chronic stable heart failure and left ventricular systolic dysfunction caused by coronary artery disease.

DESIGN

Randomised, double blind, placebo controlled study.

SETTING

Chronic stable heart failure.

PATIENTS AND INTERVENTION

34 patients with chronic stable heart failure and left ventricular systolic function taking part in the CHRISTMAS trial (double blind carvedilol v placebo) underwent CMR before randomisation and after six months of treatment.

MAIN OUTCOME MEASURE

Left ventricular remodelling at six months.

RESULTS

The carvedilol and placebo groups were well balanced at baseline, with no significant intergroup differences. Over the study period, there was a significant reduction in end systolic volume index (ESV(I)) and end diastolic volume index (EDV(I)) between the carvedilol and the placebo group (carvedilol -9 v placebo +3 ml/m2, p = 0.0004; carvedilol -8 v placebo 0 ml/m2, p = 0.05). The ejection fraction increased significantly between the groups (carvedilol +3% v placebo -2%, p = 0.003).

CONCLUSIONS

Treatment of chronic stable heart failure with carvedilol results in significant improvement in left ventricular volumes and function. These effects might contribute to the benefits of carvedilol on mortality and morbidity in patients with chronic heart failure.

Effects of passive cardiac containment on left ventricular structure and function: verification by volume and flow measurements

BACKGROUND

The cardiac support device (CSD, Acorn) is a compliant, textile-mesh graft placed around the ventricles to prevent further dilatation and to improve function in congestive heart failure. The aim of this study was to verify post-operative changes in left ventricular volumes, ejection fraction, blood flow, and myocardial mass.

METHODS

Fourteen patients underwent contrast-enhanced, electrocardiography-triggered electron-beam computerized tomography before and 6 to 9 months after CSD implantation. We measured volume and flow using the slice-summation method and the indicator-dilution technique.

RESULTS

We found significant changes for the following parameters: end-diastolic volume decreased from 382.9 +/- 140.2 ml to 311.3 +/- 138.7 ml, end-systolic volume from 310.4 +/- 132.4 ml to 237.4 +/- 133.8 ml, end-diastolic diameter from 75.3 +/- 7.8 mm to 70.7 +/- 11.6 mm, end-systolic diameter from 65.8 +/- 7.8 mm to 60.0 +/- 14.0 mm, and myocardial mass from 298.6 +/- 79.6 g to 263.1 +/- 76.8 g. Ejection fraction increased from 20.3% +/- 6.4% to 27.8% +/- 13.1%. We found no significant differences for stroke volume (from 72.5 +/- 24.6 ml to 73.8 +/- 23.6 ml), heart rate (from 80.5 +/- 11.0 beats per minute to 76.5 +/- 6.8 beats per minute), and total cardiac output (from 5.8 +/- 1.9 liter/min to 5.6 +/- 1.8 liter/min). Mitral regurgitation fraction decreased from 30.5% +/- 15.5% to 15.6% +/- 12.8%, increasing antegrade cardiac output from 3.8 +/- 0.9 liter/min to 4.7+/-1.5 liter/min. For most parameters, pre- and post-operative values in these patients differed significantly from those in an age- and gender-matched control group. In each patient, we observed a small hyperdense stripe along the pericardium after surgery, but we observed no local complications.

CONCLUSION

Three-dimensional structural and functional data obtained by computerized tomography volume and flow measurements confirm the safety and efficacy of CSD implantation.

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.

Increased exercise ejection fraction and reversed remodeling after long-term treatment with metoprolol in congestive heart failure: a randomized, stratified, double-blind, placebo-controlled trial in mild to moderate heart failure due to ischemic or idiop

BACKGROUND

the effects of long-term administration of beta-blockers on left ventricular (LV) function during exercise in patients with ischemic heart disease (IHD) and idiopathic dilated cardiomyopathy (DCM) are controversial.

PATIENTS AND METHODS

patients with stable congestive heart failure (CHF) (New York heart association [NYHA] class II and III) and ejection fraction (EF) < or =0.40 were randomized to metoprolol, 50 mg t.i.d. or placebo for 6 months. Patients were divided into two groups: ischemic heart disease (IHD) and idiopathic dilated cardiomyopathy (DCM). The mean EF was 0.29 in both groups and 92% were taking angiotensin-converting enzyme (ACE) inhibitors. In the IHD group, 84% had suffered a myocardial infarction (MI) and 64% had undergone revascularization at least 6 months before the study. LV volumes were measured by equilibrium radionuclide angiography. Mitral regurgitation was assessed by Doppler echocardiography. All values are changes for metoprolol subtracted by changes for placebo.

RESULTS

metoprolol improved LV function markedly both at rest and during sub-maximal exercise in both groups. The mean increase in EF was 0.069 at rest (P<0.001) and 0.078 during submaximal exercise (P<0.001). LV end-diastolic volume decreased by 22 ml at rest (P=0.006) and by 15 ml during exercise (P=0.006). LV end-systolic volume decreased by 23 ml both at rest (P=0.001) and during exercise (P=0.004). Exercise time increased by 39 s (P=0.08). In the metoprolol group, mitral regurgitation decreased (P=0.0026) and only one patient developed atrial fibrillation vs. eight in the placebo group (P=0.01).

CONCLUSION

metoprolol improves EF both at rest and during submaximal exercise and prevents LV dilatation in mild to moderate CHF due to IHD or DCM.

The non-invasive assessment of hibernating myocardium in ischaemic cardiomyopathy--a myriad of techniques

Heart failure is placing an ever-increasing burden on society. Many subjects with heart failure and underlying coronary artery disease have a significant amount of akinetic but viable myocardium that is able to contract should myocardial perfusion improve (hibernating myocardium). Non-randomised studies have shown prognostic benefit in subjects with hibernating myocardium undergoing revascularisation. Several non-invasive techniques have been developed to assess the presence or absence of hibernating myocardium. This review will examine the epidemiology and underlying pathogenesis of hibernating myocardium; evaluate the non-invasive techniques for diagnosing hibernating myocardium, and look at therapeutic intervention in subjects with hibernating myocardium.

Heart failure: a hemodynamic disorder complicated by maladaptive proliferative responses

Heart failure has traditionally been viewed as a hemodynamic syndrome characterized by fluid retention, high venous pressure, and low cardiac output. Over the past decade, however, it has become clear that because of deterioration and progressive dilatation (remodeling) of the diseased heart, this is also a rapidly fatal syndrome. The importance of prognosis came to be appreciated when clinical trials showed that therapy which initially improves such functional abnormalities, as high venous pressure and low cardiac output, often fail to improve survival, and that some drugs which improve hemodynamics worsen long-term prognosis. The latter is true for most vasodilators which, in spite of alleviating the adverse short-term consequences of high afterload, shorten survival. Notable exceptions are ACE inhibitors, whose vasodilator effects do not explain their ability to prolong survival; instead, these drugs slow both deterioration and remodeling of the failing heart. Inotropic agents, while providing immediate relief of symptoms, generally shorten long-term survival, whereas beta-blockers slow deterioration and remodeling, and reduce mortality. Aldosterone antagonists exert beneficial effects on prognosis that are not easily explained by their diuretic effects, but instead can be explained by their ability to inhibit signaling pathways that stimulate maladaptive hypertrophy, remodeling, apoptosis and other deleterious responses that cause deterioration of the failing heart. These and other findings demonstrate that heart failure is more than a hemodynamic disorder; these patients suffer from maladaptive proliferative responses that cause cardiac cell death and progressive dilatation that play a key role in determining the poor prognosis in this syndrome.

Proliferative signaling and disease progression in heart failure

Therapy for heart failure has traditionally been directed to such short-term functional abnormalities as low cardiac output, high filling pressures, and fluid retention. More recently, it has become clear that therapy must also inhibit the proliferative responses that contribute to the progressive deterioration of the failing heart. That heart failure is more than a hemodynamic disorder became apparent when clinical trials showed that drugs that improve such functional abnormalities as high venous pressure and low cardiac output failed to improve long-term prognosis. Most vasodilators, in spite of alleviating short-term problems caused by excessive afterload, increase long-term mortality; the notable exceptions are ACE inhibitors, the ability of which to prolong survival and inhibit remodeling can be attributed to inhibition of proliferative signaling. Other clinical trials showed that inotropic drugs, while providing immediate relief of symptoms, generally shorten long-term survival, whereas beta-adrenergic receptor blockers, which inhibit proliferative signaling by norepinephrine, improve prognosis. These findings can be explained by crossovers between functional and proliferative signaling, among the most important of which is the ability of neurohumoral mediators, such as norepinephrine and angiotensin II, to stimulate maladaptive hypertrophy, remodeling, apoptosis and other deleterious proliferative responses in the failing heart. The emerging understanding of the role of cytoskeletal and cell adhesion molecules in activating maladaptive proliferative responses suggests additional targets for therapy, and the rapid pace of discovery in molecular biology promises additional opportunities to inhibit this abnormal signaling, which causes progressive ventricular dilatation (remodeling) and cardiac cell death, now recognized to be major problems in this syndrome.