Congestive heart failure in Latin America: the next epidemic

Coronary artery disease is the main cause of congestive heart failure (CHF) in all populations. Latin American countries (LAC) are undergoing the first phase of an epidemic of coronary artery disease that probably will lead to an increased incidence of CHF. The progressive implementation of successful interventions, such as early reperfusion and rehabilitation programs, should increase the survival of patients with acute myocardial infarction and the population at high risk of CHF. The increasing prevalence of risk factors, such as diabetes, hypertension, and obesity, and the ageing of the population may also contribute to a rising incidence of CHF in LAC. Moreover, infectious diseases such as Chagas disease and rheumatic heart disease, known causes of CHF, are still frequent in this population and additionally contribute to the incidence of CHF. If timely preventive interventions are not implemented, CHF could become one of the main contributors to the burden of morbidity, mortality, and health costs in LAC. Properly conducted clinical and epidemiologic studies are needed to identify, implement, and evaluate preventive strategies that are likely to succeed within the specific context of LAC.     

Effect of pimobendan on exercise capacity in patients with heart failure: main results from the Pimobendan in Congestive Heart Failure (PICO) trial.

PRIMARY OBJECTIVE: To determine the effects of pimobendan 2.5 and 5 mg daily on exercise capacity in patients with chronic heart failure. DESIGN: A randomised, double blind, placebo controlled trial of the addition of pimobendan to conventional treatment with a minimum follow up of 24 weeks. SETTING: Outpatient cardiology clinics in six European countries. PATIENTS: 317 patients with stable symptomatic heart failure, objectively impaired exercise capacity, and an ejection fraction of 45% or lower who were treated with at least an angiotensin converting enzyme inhibitor and a diuretic and who tolerated a test dose of pimobendan. RESULTS: Compared with placebo, both pimobendan 2.5 and 5 mg daily improved exercise duration (bicycle ergometry) by 6% (P = 0.03 and 0.05) after 24 weeks of treatment. At that time 63% of patients allocated to pimobendan and 59% of those allocated to placebo were alive and able to exercise to at least the same level as at entry (P = 0.5). No significant effects on oxygen consumption (assessed in a subgroup of patients) and on quality of life (assessed by questionnaire) were observed. Pimobendan was well tolerated. Proarrhythmic effects (24-hour electrocardiography) were not observed. In both pimobendan groups combined the hazard of death was 1.8 (95% confidence interval 0.9 to 3.5) times higher than in the placebo group. CONCLUSIONS: Pimobendan improves exercise capacity in patients with chronic heart failure who are also on conventional treatment. The balance between benefit and risk of treatment with this compound remains to be established however.     

Rationale and design of a study assessing treatment strategies of atrial fibrillation in patients with heart failure: the Atrial Fibrillation and Congestive Heart Failure (AF-CHF) trial

Background Nonrandomized studies suggest that atrial fibrillation is independently associated with increased mortality in patients with heart failure. Whether restoring and maintaining sinus rhythm will have a beneficial impact on cardiovascular mortality in patients with heart failure has never been tested in an adequately powered randomized trial. Objective The primary objective of the Atrial Fibrillation and Congestive Heart Failure (AF-CHF) trial is to determine whether restoring and maintaining sinus rhythm significantly reduces cardiovascular mortality compared with a rate-control strategy in patients with atrial fibrillation and CHF. Methods AF-CHF is a prospective multicenter trial (109 centers in Canada, United States, South America, Europe, and Israel), that will randomize 1450 patients with CHF with left ventricular ejection fraction ≤35% and atrial fibrillation to 1 of 2 treatment strategies: (1) rhythm control with the use of electrical cardioversion combined with antiarrhythmic drugs (amiodarone or other class III agents), (2) rate control with the use of β-blockers, digoxin, or pacemaker and AV nodal ablation. Cardiovascular mortality is the primary end point and the intention-to-treat approach the primary method of analysis. We anticipate an 18.75% 2-year cardiovascular mortality in the rate control arm with a 25% mortality reduction in the rhythm control group. Results As of August 13, 2002, 334 patients have been enrolled from 68 participating centers. Enrollment is expected to be concluded in May 2003 with a minimum follow-up of 2 years. Conclusion The results of this trial should provide definitive information concerning 2 widely applicable treatment strategies of atrial fibrillation in a large cohort of patients with CHF. (Am Heart J 2002;144:597-607.)     

Digoxin use and heart failure outcomes: results from the Valsartan Heart Failure Trial (Val-HeFT)

Several retrospective studies have raised concerns regarding digoxin therapy in select subgroups of heart failure patients. To assess the impact of digoxin therapy on outcomes in the current era of heart failure therapy, the authors analyzed data representing 5010 patients enrolled in the Valsartan Heart Failure Trial (Val-HeFT) to examine the relationship of baseline digoxin use and all-cause mortality, first morbid event, and heart failure hospitalizations. At baseline, 3374 patients (67%) were receiving digoxin therapy and 1636 (33%) were not. Patients receiving digoxin had features of worse heart failure with higher New York Heart Association class and lower blood pressure, ejection fraction, and β-blocker use (32.1% vs 40.8%). Digoxin use was associated with worse mortality (21.1 vs 15.0%, P<.001), first morbid event (34.6 vs 21.7, P<.001), and HF hospitalization rate (19.1 vs 10.1%, P<.001). After adjustment for baseline group differences including medical therapy and baseline rhythm, patients receiving digoxin remained at a higher risk for all-cause mortality (hazard ratio [HR], 1.28; 95% confidence interval [CI], 1.05-1.57), first morbid event (HR, 1.35; 95% CI, 1.15-1.59), and heart failure hospitalization (HR, 1.41; 95% CI, 1.12-1.78). These results remained materially unchanged with propensity matched analysis. No benefit with digoxin use was observed in this study, underscoring the need to reassess the role of digoxin in the contemporary management of heart failure.     

Prognostic value of heart rate variability in chronic congestive heart failure (Veterans Affairs' Survival Trial of Antiarrhythmic Therapy in Congestive Heart Failure)

Although the value of heart rate variability (HRV) for risk stratification after acute myocardial infarction has been demonstrated, the value of low HRV as a predictor of sudden cardiac death in patients with ischemic cardiomyopathy has not been shown convincingly to date. We retrospectively analyzed electrocardiographic data from 179 patients in the Veterans Affairs' Survival Trial of Antiarrhythmic Therapy in Congestive Heart Failure to determine if HRV (expressed as the SD of the normal-to-normal RR intervals [SDNN]) would be useful as a predictor of overall mortality and sudden death. Because our goal was to identify high-risk patients, we compared patients in the lowest quartile of HRV with the remaining patients. Among the 127 patients meeting inclusion criteria, SDNN <65.3 ms (the lowest quartile) was the sole independent factor predictive of survival in a multivariate model (p = 0.0001). A Cox proportional-hazards model revealed that each increase of 10 ms in SDNN conferred a 20% decrease in risk of mortality (p = 0.0001). Furthermore, patients with SDNN <65.3 ms had a significantly increased risk of sudden death (p = 0.016). Thus, HRV was the sole independent predictor of overall mortality and was significantly associated with sudden death in this population.     

Ultrafiltration versus usual care for hospitalized patients with heart failure: the Relief for Acutely Fluid-Overloaded Patients With Decompensated Congestive Heart Failure (RAPID-CHF) trial.

OBJECTIVES: The purpose of this research was to assess the safety and efficacy of ultrafiltration (UF) in patients admitted with decompensated congestive heart failure (CHF). BACKGROUND: Ultrafiltration for CHF is usually reserved for patients with renal failure or those unresponsive to pharmacologic management. We performed a randomized trial of UF versus usual medical care using a simple UF device that does not require special monitoring or central intravenous access. METHODS: Patients admitted for CHF with evidence of volume overload were randomized to a single, 8 h UF session in addition to usual care or usual care alone. The primary end point was weight loss 24 h after the time of enrollment. RESULTS: Forty patients were enrolled (20 UF, 20 usual care). Ultrafiltration was successful in 18 of the 20 patients in the UF group. Fluid removal after 24 h was 4,650 ml and 2,838 ml in the UF and usual care groups, respectively (p = 0.001). Weight loss after 24 h, the primary end point, was 2.5 kg and 1.86 kg in the UF and usual care groups, respectively (p = 0.240). Patients tolerated UF well. CONCLUSIONS: The early application of UF for patients with CHF was feasible, well-tolerated, and resulted in significant weight loss and fluid removal. A larger trial is underway to determine the relative efficacy of UF versus standard care in acute decompensated heart failure.     

Overview of Acutely Decompensated Congestive Heart Failure (ADHF): A Report from the ADHERE Registry

Acute decompensated heart failure (ADHF) has emerged as a major public health problem, and HF has become the leading cause of hospitalization in persons over 65 years of age. It is estimated that there are 6.5 million hospital days attributed to ADHF each year. Patients hospitalized with ADHF face a substantial risk of readmission, as high as 50% by 6 months after discharge. Despite the large number of patients hospitalized and this substantial risk, data on these patients have been limited and there has been little effort to improve the quality of care for patients hospitalized with ADHF. The Acute Decompensated Heart Failure National Registry (ADHERE®) was designed to bridge this gap in knowledge and care by prospectively studying the characteristics, management, and outcomes of a broad spectrum of patients hospitalized with ADHF. Participating community and university hospitals identified patients with a primary or secondary discharge diagnosis of HF and collected medical history, management, treatments, and health outcomes via secure Web browser technology. As of October 2004, more than 160,000 patients from 281 hospitals have been enrolled. These patients differ substantially from those typically enrolled in randomized clinical trials. Initial data from the ADHERE registry have provided important insights into the clinical characteristics, patterns of care, and outcomes of patients with ADHF. ADHERE has documented significant delays in diagnosis and initiation of ADHF therapies as well as a substantial under-use of evidenced-based, guideline-recommended chronic HF therapies at hospital discharge. As such, there are substantial opportunities to improve the quality of care for ADHF patients in the nations hospitals.Dr. Fonarow has received research grants, is a consultant for, and is a member of the Speakers Bureau of, Scios Inc. ADHERE is sponsored by Scios Inc., Fremont, CA.