Generation and characterization of induced pluripotent stem cells from breast cancer patients carrying ATM mutations

We generated two induced pluripotent stem cell (iPSC) lines from peripheral blood mononuclear cells (PBMCs) of breast cancer patients carrying germline ATM mutations, a gene associated with a 7% prevalence in breast cancer. These iPSC lines displayed typical morphology, expressed pluripotency markers, maintained a stable karyotype, and retained the ability to differentiate into the three germ layers. These patient-specific iPSC lines hold great potential for mechanistic investigations and the development of drug screening strategies aimed at addressing ATM-related cancer.

Abstract 350: Immune Profiling and Causal Antigen Discovery in Mouse and Human Models of Immune Checkpoint Inhibitor-induced Myocarditis

Introduction: Immune checkpoint inhibitors (ICIs) are novel drugs that activate T cell-mediated anti-tumor response by blocking immune checkpoints such as PD-1 or CTLA-4, leading to improved cancer patient survival. Despite these benefits, ICIs can result in autoimmune side effects including fulminant myocarditis and heart failure. While ICI-induced myocarditis is characterized by myocardial T cell infiltration, the causal mechanisms remain unknown. We hypothesize that ICI-induced myocarditis is caused by cardiac-specific auto-antigens triggering clonal expansion of myocardial CD8+ T-cells, leading to T-cell mediated myocardial damage.

Methods/Results: We have explored the ICI-induced inflammatory response in a mouse model of myocarditis induced by PD-1 knockout and in patients with ICI-induced myocarditis. PD-1 deficient-mice on a lupus-like autoimmune background (i.e. MRL/Pcd1-/- mice) develop spontaneous fatal myocarditis in 70% of animals by 5 weeks of age, with massive cardiac infiltration of CD8>CD4+ T-cells. Likewise, patients with ICI-induced myocarditis have CD8>CD4+ T-cell infiltrate in the heart. We have performed time-of-flight mass cytometry (CyTOF) to immunophenotype the T-cell subsets in the blood/myocardium of MRL/Pcd1-/- mice and in ICI-myocarditis patients. We have also conducted single cell sequencing of T-cell receptors (TCRs) from the blood +/- myocardial-derived T-cell samples of the mice and patients. Our preliminary results in ICI-myocarditis patients confirmed the previously reported CD8+ T-cell expansion in the blood and myocardium of myocarditis patients compared with healthy control. We are currently identifying candidate cardiac auto-antigen(s) responsible for this disease by performing Grouping Lymphocyte Interactions by Paratope Hotspots (GLIPH).

Conclusion: Myocarditis is a serious and life-threatening complication of ICI treatment. By understanding the unique immune response present during ICI-induced myocarditis and the responsible cardiac auto-antigen(s) involved, we will pave the way for the development of adjuvant therapies that target these antigens and mitigate their deleterious effects.

Dipeptidyl peptidase 4 inhibition increases myocardial glucose uptake in nonischemic cardiomyopathy

BACKGROUND

Glucose and fatty acids comprise the primary substrates for myocardial energy metabolism. The normal myocardium switches toward glucose metabolism in the setting of stress; the inability to affect such a switch is a fundamental mechanism behind "diabetic" or "insulin-resistant" cardiomyopathy. The purpose of this mechanistic study was to evaluate the effects of treatment with the dipeptidyl peptidase (DPP) 4 inhibitor sitagliptin on myocardial glucose uptake in patients with nonischemic cardiomyopathy.

METHODS AND RESULTS

Twelve nondiabetic subjects with nonischemic cardiomyopathy underwent metabolic testing and assessment of myocardial glucose uptake by (18)F-fluorodeoxyglucose positron-emission tomographic/computerized tomographic imaging at baseline and after 4 weeks of sitagliptin therapy. Sitagliptin therapy resulted in a significant increase in myocardial glucose uptake (19% increase; P = .04). Although most patients had at least a slight increase in glucose uptake, there was an overall bimodal response, with 6 patients ("responders") demonstrating large increases (>20%) in glucose uptake and 6 patients ("nonresponders") demonstrating <5% increases or slight decreases. Triglyceride-high-density lipoprotein ratios significantly dropped in the 6 responders compared with the 6 nonresponders (P < .02).

CONCLUSIONS

Therapy with the DPP-4 inhibitor sitagliptin results in increased myocardial glucose uptake in nondiabetic patients with nonischemic cardiomyopathy.

Chemotherapy-associated cardiotoxicity: how often does it really occur and how can it be prevented?

Cardiotoxicity remains the limiting factor for many forms of cancer therapy and is the focus of growing research and clinical emphasis. This article outlines the current clinical evidence for left ventricular dysfunction and heart failure for the two most important classes of cardiotoxic chemotherapeutic agents, examines the potential pitfalls that have led to underestimated rates of left ventricular dysfunction from these agents, and reviews strategies for screening for and providing prophylaxis against chemotherapy-associated left ventricular dysfunction.

Dyssynchrony Assessment with Tissue Doppler Imaging and Regional Volumetric Analysis by 3D Echocardiography Do Not Predict Long-Term Response to Cardiac Resynchronization Therapy

Background. Currently there are no reliable predictors of response to cardiac resynchronization therapy (CRT) before implantation. We compared pre-CRT left ventricular (LV) dyssynchrony by tissue Doppler imaging (TDI) and regional volumetric analysis by 3-dimensional transthoracic echocardiography (3DTTE) in predicting response to CRT. Methods. Thirty-eight patients (79% nonischemic cardiomyopathy) with symptomatic heart failure who underwent CRT were enrolled. Clinical and echocardiographic responses were defined as improvement in one NYHA class and reduction in LV end-systolic volume by ≥15% respectively. Functional status was assessed by Minnesota Living with Heart Failure questionnaire and 6-minute walk distance. Results. In 33 patients, after CRT for 7.86 ± 2.27 months, there were 24 (73%) clinical and 19 (58%) echocardiographic responders. Functional parameters, LV dimensions, volumes and synchrony by TDI and 3DTTE improved significantly in responders. There was no difference in the number of responders and nonresponders when cut-off values for dyssynchrony by different measurements validated in other trials were applied. Area under receiver-operating-characteristic curve ranged from 0.4 to 0.6. Conclusion. CRT improves clinical and echocardiographic parameters in patients with systolic heart failure. The dyssynchrony measurements by TDI and 3DTTE are not comparable and are unable to predict response to CRT.

Measurement precision in the optimization of cardiac resynchronization therapy

BACKGROUND

Cardiac resynchronization therapy improves morbidity and mortality in appropriately selected patients. Whether atrioventricular (AV) and interventricular (VV) pacing interval optimization confers further clinical improvement remains unclear. A variety of techniques are used to estimate optimum AV/VV intervals; however, the precision of their estimates and the ramifications of an imprecise estimate have not been characterized previously.

METHODS AND RESULTS

An objective methodology for quantifying the precision of estimated optimum AV/VV intervals was developed, allowing physiologic effects to be distinguished from measurement variability. Optimization using multiple conventional techniques was conducted in individual sessions with 20 patients. Measures of stroke volume and dyssynchrony were obtained using impedance cardiography and echocardiographic methods, specifically, aortic velocity-time integral, mitral velocity-time integral, A-wave truncation, and septal-posterior wall motion delay. Echocardiographic methods yielded statistically insignificant data in the majority of patients (62%-82%). In contrast, impedance cardiography yielded statistically significant results in 84% and 75% of patients for AV and VV interval optimization, respectively. Individual cases demonstrated that accepting a plausible but statistically insignificant estimated optimum AV or VV interval can result in worse cardiac function than default values.

CONCLUSIONS

Consideration of statistical significance is critical for validating clinical optimization data in individual patients and for comparing competing optimization techniques. Accepting an estimated optimum without knowledge of its precision can result in worse cardiac function than default settings and a misinterpretation of observed changes over time. In this study, only impedance cardiography yielded statistically significant AV and VV interval optimization data in the majority of patients.

Insulin-resistant cardiomyopathy clinical evidence, mechanisms, and treatment options

Increasing evidence points to insulin resistance as a primary etiologic factor in the development of nonischemic heart failure (HF). The myocardium normally responds to injury by altering substrate metabolism to increase energy efficiency. Insulin resistance prevents this adaptive response and can lead to further injury by contributing to lipotoxicity, sympathetic up-regulation, inflammation, oxidative stress, and fibrosis. Animal models have repeatedly demonstrated the existence of an insulin-resistant cardiomyopathy, one that is characterized by inefficient energy metabolism and is reversible by improving energy use. Clinical studies in humans strongly support the link between insulin resistance and nonischemic HF. Insulin resistance is highly prevalent in the nonischemic HF population, predates the development of HF, independently defines a worse prognosis, and predicts response to antiadrenergic therapy. Potential options for treatment include metabolic-modulating agents and antidiabetic drugs. This article reviews the basic science evidence, animal experiments, and human clinical data supporting the existence of an "insulin-resistant cardiomyopathy" and proposes specific potential therapeutic approaches.

Insulin-resistant cardiomyopathy clinical evidence, mechanisms, and treatment options

Increasing evidence points to insulin resistance as a primary etiologic factor in the development of nonischemic heart failure (HF). The myocardium normally responds to injury by altering substrate metabolism to increase energy efficiency. Insulin resistance prevents this adaptive response and can lead to further injury by contributing to lipotoxicity, sympathetic up-regulation, inflammation, oxidative stress, and fibrosis. Animal models have repeatedly demonstrated the existence of an insulin-resistant cardiomyopathy, one that is characterized by inefficient energy metabolism and is reversible by improving energy use. Clinical studies in humans strongly support the link between insulin resistance and nonischemic HF. Insulin resistance is highly prevalent in the nonischemic HF population, predates the development of HF, independently defines a worse prognosis, and predicts response to antiadrenergic therapy. Potential options for treatment include metabolic-modulating agents and antidiabetic drugs. This article reviews the basic science evidence, animal experiments, and human clinical data supporting the existence of an "insulin-resistant cardiomyopathy" and proposes specific potential therapeutic approaches.

Beta-blocker dosing in community-based treatment of heart failure

BACKGROUND

Community patients with heart failure (HF) are older, less often treated by HF specialists, and have more comorbidity than those in randomized clinical trials. These differences might affect beta-blocker prescribing in HF.

METHODS

To explore patterns of beta-blocker prescribing for HF in the community and their association with outcomes, we determined carvedilol doses at end titration in 4113 patients from a community-based beta-blocker HF registry according to physician and patient characteristics, HF severity, and rates of hospitalization and death.

RESULTS

Female sex, age > or = 65 years, and left ventricular ejection fraction > or = 35% were associated with lower beta-blocker doses. Average daily dose of beta-blocker was lower with worse baseline New York Heart Association class. More patients of cardiologists achieved carvedilol doses > or = 25 mg twice daily, whereas in those of noncardiologists lower doses were more common. Relative risk of HF hospitalizations or all-cause death was significantly lower with higher doses of beta-blocker.

CONCLUSIONS

Beta-blocker dosing in community HF appears lower than in randomized clinical trials, especially when prescribed by noncardiologists. At all doses, patients taking the beta-blocker carvedilol have a lower incidence of death and HF hospitalization than those discontinuing it, regardless of physician type in the community setting.

Comparison of outcomes and usefulness of carvedilol across a spectrum of left ventricular ejection fractions in patients with heart failure in clinical practice

Heart failure (HF) in the community differs meaningfully from that in clinical trials, particularly the higher prevalence of patients with preserved left ventricular (LV) ejection fraction (EF) typically excluded from clinical trials, thus limiting knowledge of their responsiveness to beta-blocker therapy. From a community-based registry of 4,280 patients with HF starting treatment with the beta blocker carvedilol, we compared characteristics, carvedilol titration, and outcomes of patients according to LVEF >40% or <40% (as in clinical trials) and across the spectrum of LVEF <21%, 21% to 30%, 31% to 40%, and >40%. Patients with preserved EF (LVEF >40%) were older and more often women and hypertensive. Lower LVEF was associated with worse functional class and more HF hospitalizations in the previous year. Carvedilol dose decreased with increasing LVEF. Hospitalization rates for HF related inversely to LVEF before starting carvedilol therapy and decreased from the previous year in all LVEF groups during follow-up. Although 1-year mortality rate decreased from 8% with LVEF < or =20% to 6% with LVEF >40%, adjusted hazard ratios were not significantly different across LVEF groups. Thus, characteristics of community patients with HF vary across the spectrum of LVEF. Patients with HF and preserved EF treated with carvedilol in the community improve symptomatically and experience fewer HF hospitalizations after initiating carvedilol. In conclusion, without a control group, the effect of carvedilol on outcomes is not conclusive and trials of carvedilol in patients with HF and preserved EF should be undertaken.

Tolerability, safety, and efficacy of beta-blockade in black patients with heart failure in the community setting: insights from a large prospective beta-blocker registry

Heart failure (HF) clinical trials suggest different responses of blacks and whites to beta-blockers. Differences between clinical trial and community settings may also have an impact. The Carvedilol Heart Failure Registry (COHERE) observed experience with carvedilol in 4280 patients with HF in a community setting. This analysis compares characteristics, outcomes, and carvedilol dosing of blacks and whites in COHERE. Compared with whites (n=3433), blacks (n=523) had more severe HF symptoms despite similar systolic function. At similar carvedilol maintenance doses, symptoms improved in 33% of blacks vs 28% of whites, while worsening in 10% and 11%, respectively (both nonsignificant), and HF hospitalization rates were reduced comparably in both groups (-58% vs -56%, respectively; both P<.001). Incidence and hazard ratios of death were similar in blacks and whites (6.9% vs 7.5%, hazard ratio 1.2 vs 1.0, P=.276). Thus carvedilol was similarly effective in blacks and whites with HF in the community setting, consistent with carvedilol clinical trials.

Predictors of clinical outcomes in patients given carvedilol for heart failure

Risk factors for outcomes in heart failure (HF) were derived from populations in clinical trials, at hospital discharge, or in localized geographic or socioeconomic strata before the widespread use of beta blockers. This study observed 4,280 patients in a community-based HF registry for 1 year after completing carvedilol titration. Independent risk factors for death, hospitalization for HF, or hospitalization for cardiovascular reasons other than HF were first identified by age-, gender-, and race-adjusted analyses, then by multivariate analysis adjusted simultaneously for all factors. Over this period, 7% of patients died, 11% were hospitalized for HF, 12% were hospitalized for other cardiovascular reasons, and 27% had > or =1 of these events. The most significant outcome predictors were New York Heart Association class III or IV, history of hospitalization for HF or other cardiovascular reasons, and angina pectoris, all associated with increased odds of having an adverse outcome (all p < or =0.001). The left ventricular ejection fraction was not a significant outcome predictor by multivariate analysis. The odds ratio for an adverse outcome was significantly reduced for patients with hypertensive or idiopathic causes of HF and for those whose physicians had graduated from medical school > or =24 years earlier compared with <14 years earlier (all p <0.005). In conclusion, easily obtained historical information predicts clinical outcomes in patients with HF in the year after initiating carvedilol. In this unselected community population, these historical factors were better predictors of risk than the left ventricular ejection fraction.

Emerging therapies for the management of decompensated heart failure: from bench to bedside

While pharmaceutical innovation has been highly successful in reducing mortality in chronic heart failure, this has not been matched by similar success in decompensated heart failure syndromes. Despite outstanding issues over definitions and end points, we argue in this paper that an unprecedented wealth of pharmacologic innovation may soon transform the management of these challenging patients. Agents that target contractility, such as cardiac myosin activators and novel adenosine triphosphate-dependent transmembrane sodium-potassium pump inhibitors, provide inotropic support without arrhythmogenic increases in cytosolic calcium or side effects of more traditional agents. Adenosine receptor blockade may improve glomerular filtration and diuresis by exerting a direct beneficial effect on glomerular blood flow while vasopressin antagonists promote free water excretion without compromising renal function and may simultaneously inhibit myocardial remodeling. Urodilatin, the renally synthesized isoform of atrial natriuretic peptide, may improve pulmonary congestion via vasodilation and enhanced diuresis. Finally, metabolic modulators such as perhexiline may optimize myocardial energy utilization by shifting adenosine triphosphate production from free fatty acids to glucose, a unique and conceptually appealing approach to the management of heart failure. These advances allow optimism not only for the advancement of our understanding and management of decompensated heart failure syndromes but for the translational research effort in heart failure biology in general.

Heart Failure in Community Practice: Relationship to Age and Sex in a ?-Blocker Registry

Women and the elderly are underrepresented in clinical trials of heart failure (HF). The authors analyzed, by sex and age groups, a registry of 4280 community patients initiating carvedilol for HF. Women (n=1485) were older than men (n=2793) and had worse functional class with higher left ventricular ejection fraction and blood pressure. Women also had more HF hospitalizations, less use of angiotensin-converting enzyme inhibitors, and lower doses of carvedilol. Nevertheless, during 1-year follow-up, both groups experienced greater than 40% reductions in HF hospitalizations (P<.001), with mortality of 7.3% in women vs 9.1% in men (P=.085). With increasing age, left ventricular ejection fraction, blood pressure, and functional class increased, whereas angiotensin-converting enzyme inhibitor use and carvedilol doses decreased. HF hospitalizations fell at least 40% in all age groups after starting carvedilol (P<.001). Characteristics of women and the elderly with HF in the community suggest increased risk, but both populations respond well after initiating carvedilol.

The effect of carvedilol on mortality risk in heart failure patients with diabetes: results of a meta-analysis

BACKGROUND

Although beta-blocker therapy has been shown to improve survival in patients with chronic heart failure, this class of drugs tends to be underutilized in diabetic patients due to concerns about adverse metabolic effects, especially on glycemic control. No randomized clinical trial has specifically evaluated the effect of beta-blocker therapy on mortality in diabetic patients with heart failure. Previous meta-analyses combining results of heart failure trials with pharmacologically diverse beta-blockers suggest that the survival benefit in diabetic patients may be diminished compared to benefits in non-diabetic patients. However, some trial results indicate that carvedilol, which blocks beta1-, beta2-, and alpha1-receptors and is a potent antioxidant, may produce at least comparable effects in both patient groups.

OBJECTIVES

To evaluate the effect of carvedilol in patients with heart failure and diabetes, specifically to determine if the survival benefit of carvedilol demonstrated in heart failure trials was as great in the subgroups of patients with diabetes.

METHODS

A meta-analysis was performed that included 5757 patients with heart failure, 25% of whom had diabetes, from seven large placebo-controlled randomized trials with carvedilol. All large (> 100 patients) placebo-controlled, randomized trials with carvedilol in heart failure were included. The endpoint of all-cause mortality was examined in the overall population, patients without diabetes, and patients with diabetes. The number of patients needed to treat (NNT) for 1 year to prevent one death associated with carvedilol use in diabetic versus non-diabetic patients was also calculated. The log-rank test and the Cox proportional hazards regression were used to compare the event time distributions of carvedilol versus placebo with respect to the outcome of mortality.

RESULTS

Similar survival benefits were seen with carvedilol use in diabetic and non-diabetic patients (relative risk reductions of 28% [95% confidence interval (CI) 3-46%; p = 0.03] and 37% [95% CI 22-48%; p < 0.001], respectively). There were no significant differences between the relative mortality risk reductions or the NNT with carvedilol use in diabetic versus non-diabetic patients. The NNT for 1 year to prevent one death was 23 for all patients, as well as for non-diabetic patients, and 25 for the diabetic group.

CONCLUSIONS

This meta-analysis provides evidence that the same survival benefit may occur with carvedilol in heart failure patients with and without diabetes. The low NNT in the severe heart failure trial, COPERNICUS, and the diabetic subgroup in this meta-analysis suggests that severe heart failure patients and heart failure patients with diabetes may particularly derive benefit from therapy with carvedilol.

Are beta-blockers needed in patients receiving spironolactone for severe chronic heart failure? An analysis of the COPERNICUS study

BACKGROUND

The beneficial effects of beta-blockers and aldosterone receptor antagonists are now well established in patients with severe systolic chronic heart failure (CHF). However, it is unclear whether beta-blockers are able to provide additional benefit in patients already receiving aldosterone antagonists. We therefore examined this question in the COPERNICUS study of 2289 patients with severe CHF receiving the beta1-beta2/alpha1 blocker carvedilol compared with placebo.

METHODS

Patients were divided post hoc into subgroups according to whether they were receiving spironolactone (n = 445) or not (n = 1844) at baseline. Consistency of the effect of carvedilol versus placebo was examined for these subgroups with respect to the predefined end points of all-cause mortality, death or CHF-related hospitalizations, death or cardiovascular hospitalizations, and death or all-cause hospitalizations.

RESULTS

The beneficial effect of carvedilol was similar among patients who were or were not receiving spironolactone for each of the 4 efficacy measures. For all-cause mortality, the Cox model hazard ratio for carvedilol compared with placebo was 0.65 (95% CI 0.36-1.15) in patients receiving spironolactone and 0.65 (0.51-0.83) in patients not receiving spironolactone. Hazard ratios for death or all-cause hospitalization were 0.76 (0.55-1.05) versus 0.76 (0.66-0.88); for death or cardiovascular hospitalization, 0.61 (0.42-0.89) versus 0.75 (0.64-0.88); and for death or CHF hospitalization, 0.63 (0.43-0.94) versus 0.70 (0.59-0.84), in patients receiving and not receiving spironolactone, respectively. The safety and tolerability of treatment with carvedilol were also similar, regardless of background spironolactone.

CONCLUSION

Carvedilol remained clinically efficacious in the COPERNICUS study of patients with severe CHF when added to background spironolactone in patients who were practically all receiving angiotensin-converting enzyme inhibitor (or angiotensin II antagonist) therapy. Therefore, the use of spironolactone in patients with severe CHF does not obviate the necessity of additional treatment that interferes with the adverse effects of sympathetic activation, specifically beta-blockade.

Impact of angiotensin-converting enzyme gene polymorphism on neurohormonal responses to high- versus low-dose enalapril in advanced heart failure

BACKGROUND

The impact of angiotensin-converting enzyme (ACE) gene polymorphism on neurohormonal dose response to ACE inhibitor therapy is unclear.

METHODS

ACE Insertion (I) or Deletion (D) genotype was determined in 74 patients with chronic heart failure who were randomly assigned to receive either high-dose or low-dose enalapril over a period of 6 months. Monthly pre-enalapril and post-enalapril neurohormone levels (serum ACE activity (sACE), plasma angiotensin II (A-II), plasma renin activity (PRA), and serum aldosterone (ALDO) were compared between genotype subgroups and between patients who received high- or low-dose enalapril within each genotype subgroup.

RESULTS

At baseline, predose/postdose sACE and postdose PRA were significantly higher in the DD genotype. At 6-month follow-up, postdose sACE was reduced in a dose-dependent fashion in all three genotypes (P < .05). However, predose and postdose ALDO and A-II levels did not differ between each genotype subgroup at baseline or by enalapril dose within each genotype subgroup. ALDO escape and A-II reactivation were not affected by ACE genotype or enalapril dosage.

CONCLUSIONS

Predose sACE were consistently higher in the DD genotype when compared with ID or II subgroups. Despite a dose-dependent suppression of sACE, there were no observed statistically significant differences in ALDO and A-II suppression or escape with escalating doses of enalapril within each subgroup.

The potential impact of soil ingestion on human mineral nutrition

Geophagia, the intentional and repeated ingestion of soil material, is a complex eating behaviour with incomprehensible aetiology. It is generally assumed that geophagia may help supplement mineral nutrients and thus should not be dissuaded, particularly in subsistence communities. This is largely based on the assumption that a large proportion of mineral nutrients in geophagic materials is potentially available for absorption in the body. We tested this hypothesis on five soils collected from geophagia-prevalent communities by using an in vitro soil ingestion simulation test that is broadly similar to the gastrointestinal (GI) tract. The results show that, despite the soils being rich in mineral nutrients, soil ingestion, inadvertent or through geophagia can potentially reduce the absorption of already bioavailable nutrients, particularly micronutrients such as Fe, Cu and Zn. These in vitro findings, while disagreeing with the commonly held view of geophagia as a source of nutrient supplementation, are consistent with micronutrient deficiency problems observed in clinical nutrition studies conducted amongst geophagic populations. The work also showed that, in some cases, the ingested soils may become a source of Ca, Mg and Mn, although it is not clear why other similar soils should not release any of these mineral nutrients.

Prognostic Impact of Plasma N-Terminal Pro–Brain Natriuretic Peptide in Severe Chronic Congestive Heart Failure

Background— The utility of N-terminal proBNP (NT-proBNP) to predict the occurrence of death and hospitalization was prospectively evaluated in the COPERNICUS study, which enrolled patients with an ejection fraction <25% and symptoms of chronic congestive heart failure at rest or on minimal exertion.

Methods and Results— Baseline plasma concentrations of NT-proBNP were measured in a subgroup of 814 men and 197 women with symptoms at rest or on minimal exertion who were enrolled in the COPERNICUS study and were randomized to placebo (n=506) or carvedilol (n=505). Values of NT-proBNP were markedly increased despite the requirement that patients be euvolemic before the start of treatment (mean±SD, 3235±4392 pg/mL; median, 1767 pg/mL). By univariate Cox regression analysis, NT-proBNP was found to be a powerful predictor of subsequent all-cause mortality (relative risk [RR], 2.7; 95% CI, 1.7 to 4.3; P =0.0001 for above versus below median) and all-cause mortality or hospitalization for heart failure (RR, 2.4; 95% CI, 1.8 to 3.4; P =0.0001 for above versus below median). The predictive value of NT-proBNP was similar when both placebo and carvedilol patients were analyzed separately. No significant interaction was found between NT-proBNP and treatment group ( P =0.93 for above- versus below-median NT-proBNP).

Conclusions— NT-proBNP was consistently associated with increased risk for all-cause mortality and for all-cause mortality or hospitalization for heart failure in patients with severe congestive heart failure, even in those who were clinically euvolemic. This marker therefore may be a useful tool in risk stratification of patients with severe congestive heart failure.

Insulin resistance in idiopathic dilated cardiomyopathy

OBJECTIVES

This study was designed to quantify the prevalence of abnormal glucose tolerance and insulin resistance in patients with idiopathic dilated cardiomyopathy (IDCM).

BACKGROUND

Insulin resistance is an independent risk factor for mortality in patients with heart failure (HF) and is a known risk factor for ischemic cardiomyopathy. Though potential physiologic links between insulin resistance and HF have been hypothesized, the relationship between insulin resistance and IDCM remains unclear.

METHODS

A total of 230 consecutive patients from a university HF clinic were screened for IDCM, the absence of diabetes mellitus, and the lack of significant co-morbid conditions. Oral glucose tolerance tests were performed in the 43 patients with IDCM who met these criteria, and their plasma glucose and insulin responses were compared with those of 40 healthy volunteers, matched for age, gender, and body mass index.

RESULTS

Plasma glucose responses were higher during the oral glucose tolerance tests in patients with IDCM (p < 0.01), associated with significantly higher plasma insulin concentrations following the oral glucose challenge (p < 0.01). In addition, abnormalities of glucose tolerance were significantly (p < 0.05) more common in patients with IDCM (49% vs. 23%).

CONCLUSIONS

Insulin resistance and abnormal glucose tolerance are more prevalent in patients with IDCM and represent potentially reversible metabolic derangements in these individuals.

NT-proBNP in severe chronic heart failure: rationale, design and preliminary results of the COPERNICUS NT-proBNP substudy

BACKGROUND

Neither profiles nor prognostic value of cardiac N-terminal proBNP (NT-proBNP) have been prospectively evaluated in a sufficient number of patients with severe chronic heart failure (CHF) treated with carvedilol or placebo.

METHODS

Baseline and follow-up plasma concentrations of NT-proBNP were measured in the European part of the COPERNICUS Trial. This study enrolled patients with an ejection fraction <25% and symptoms of CHF at rest or on minimal exertion, equally randomized to placebo or carvedilol.

RESULTS

NT-proBNP concentrations were increased at baseline (mean+/-S.D.=579+/-822 pmol/l, median=322.5 pmol/l) with a marked decrease during follow-up in the carvedilol, but not in the placebo group. One-year mortality rates were 3.9, 12 and 27.9% in the lower, middle and upper tertiles of NT-proBNP, respectively. When mortality was calculated separately in the placebo and carvedilol group, rates were 0.8, 6.3 and 19.1% in the carvedilol treated but 6.7, 17.9 and 36.9% in the placebo treated patients.

CONCLUSIONS

NT-proBNP was a powerful predictor of subsequent all-cause mortality in patients with severe CHF. This marker should therefore be further evaluated for risk stratification and monitoring of therapy in CHF.

Influence of pretreatment systolic blood pressure on the effect of carvedilol in patients with severe chronic heart failure: the Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS) study

OBJECTIVES

We sought to evaluate the influence of pretreatment systolic blood pressure (SBP) on the efficacy and safety of carvedilol in patients with chronic heart failure (CHF).

BACKGROUND

Although beta-blockers reduce the risk of death in CHF, there is little reported experience with these drugs in patients with a low pretreatment SBP, who may respond poorly to beta-blockade.

METHODS

We studied 2,289 patients with severe CHF who participated in the Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS) trial.

RESULTS

Compared with placebo, carvedilol improved the clinical status and reduced the risk of death and the combined risk of death or hospitalization for any reason, for a cardiovascular reason, or for worsening heart failure (p < 0.001 for all). The relative magnitude of these benefits did not vary as a function of the pretreatment SBP (all interaction: p > 0.10). However, because patients with the lowest SBP were at highest risk of an event, they experienced the greatest absolute benefit from treatment with carvedilol. The lower the pretreatment SBP, the more likely that patients would report an adverse event, be intolerant of high doses of the study drug, or require permanent withdrawal of treatment (p < 0.001 for all). However, these risks were primarily related to the severity of the underlying illness and not to treatment with carvedilol.

CONCLUSIONS

The current study provides little support for concerns about using beta-blockers (particularly those with vasodilatory actions) in patients with severe CHF who have a low SBP. Pretreatment blood pressure can identify patients who have the greatest need for risk reduction with carvedilol.

Carvedilol prospective randomized cumulative survival (COPERNICUS) trial: carvedilol in severe heart failure

The impact of carvedilol on the survival of patients with severe heart failure was examined in the Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS) trial. The trial recruited 2,289 patients with symptoms at rest or on minimal exertion despite therapy with angiotensin-converting enzyme inhibitors and a left ventricular ejection fraction of < or = 0.25. After an average follow-up period of 10.4 months, mortality was reduced by 34% in the carvedilol group. Carvedilol also reduced the number of days spent in the hospital for any cause by 27% and the number of days spent in the hospital for heart failure by 40%. Patients in the carvedilol group felt better and were less likely to have a serious adverse event. The benefits of carvedilol appeared early and were detected during the up-titration period.

Effects of initiating carvedilol in patients with severe chronic heart failure: results from the COPERNICUS Study

CONTEXT

Beta-blockers remain underused despite their established utility for improving outcome in heart failure. Concerns that initiation of treatment produces few immediate benefits and may have important risks may be deterring widespread use.

OBJECTIVE

To evaluate the early effects of the beta-blocker carvedilol in patients with severe heart failure.

DESIGN, SETTING, AND PATIENTS

Randomized, double-blind, placebo-controlled trial conducted from October 28, 1997, to March 20, 2000, at 334 hospital centers in 21 countries among 2289 patients with symptoms of heart failure at rest or with minimal exertion who were clinically euvolemic and had a left ventricular ejection fraction of less than 25%.

INTERVENTION

Patients were randomly assigned to receive carvedilol, with start dosage of at 3.125 mg twice daily with uptitration to a target dosage of 25 mg twice daily (n = 1156), or placebo (n = 1133), in addition to their usual medications for heart failure.

MAIN OUTCOME MEASURES

Death, hospitalization, or permanent withdrawal from study drug, as well as adverse events during the first 8 weeks of treatment.

RESULTS

The carvedilol group experienced no increase in cardiovascular risk but instead had fewer patients who died (19 vs 25; hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.41-1.35); who died or were hospitalized (134 vs 153; HR, 0.85; 95% CI, 0.67-1.07); or who died, were hospitalized, or were permanently withdrawn from treatment (162 vs 188; HR, 0.83; 95% CI, 0.68-1.03). These effects were similar in direction and magnitude to those observed during the entire study, and were apparent particularly in the 624 patients with recent or recurrent decompensation or a very depressed left ventricular ejection fraction. Differences in favor of carvedilol became apparent as early as 14 to 21 days following initiation of treatment. Worsening heart failure was the only serious adverse event with a frequency greater than 2% and was reported with similar frequency in the placebo and carvedilol groups (6.4% vs 5.1%).

CONCLUSIONS

These data suggest that, in clinically euvolemic patients, the relation of benefit to risk during initiation of treatment with carvedilol is similar to that seen during long-term therapy with the drug. Our findings should provide the reassurance needed to encourage the high levels of use that are warranted by the results of long-term clinical trials.

Effect of carvedilol on the morbidity of patients with severe chronic heart failure: results of the carvedilol prospective randomized cumulative survival (COPERNICUS) study

BACKGROUND

Beta-blocking agents improve functional status and reduce morbidity in mild-to-moderate heart failure, but it is not known whether they produce such benefits in severe heart failure.

METHODS AND RESULTS

We randomly assigned 2289 patients with symptoms of heart failure at rest or on minimal exertion and with an ejection fraction <25% (but not volume-overloaded) to double-blind treatment with either placebo (n=1133) or carvedilol (n=1156) for an average of 10.4 months. Carvedilol reduced the combined risk of death or hospitalization for a cardiovascular reason by 27% (P=0.00002) and the combined risk of death or hospitalization for heart failure by 31% (P=0.000004). Patients in the carvedilol group also spent 27% fewer days in the hospital for any reason (P=0.0005) and 40% fewer days in the hospital for heart failure (P<0.0001). These differences were as a result of both a decrease in the number of hospitalizations and a shorter duration of each admission. More patients felt improved and fewer patients felt worse in the carvedilol group than in the placebo group after 6 months of maintenance therapy (P=0.0009). Carvedilol-treated patients were also less likely than placebo-treated patients to experience a serious adverse event (P=0.002), especially worsening heart failure, sudden death, cardiogenic shock, or ventricular tachycardia.

CONCLUSION

In euvolemic patients with symptoms at rest or on minimal exertion, the addition of carvedilol to conventional therapy ameliorates the severity of heart failure and reduces the risk of clinical deterioration, hospitalization, and other serious adverse clinical events.