Exercise intolerance in chronic heart failure is not associated with impaired recovery of muscle function or submaximal exercise performance

Objectives.This study investigated whether recovery of skeletal muscle function is impaired in patients with heart failure and whether impaired recovery is associated with abnormal submaximal systemic exercise tolerance during repeated testing.Background.Patients with heart failure experience fatigue during daily activities. Because abnormalities of skeletal muscle play a role in their exercise intolerance, these symptoms may reflect a delay in muscle recovery and a resulting limitation in submaximal exercise tolerance.Methods.Two protocols were used. In protocol 1, knee extensor strength and endurance, and their recovery after fatiguing exercise, were evaluated in 11 patients (mean [±SEM] age 62 ± 5 years, New York Heart Association functional class 2.3 ± 0.2, ejection fraction 24 ± 5%) and in 10 age-matched sedentary control subjects. Protocol 2 examined the recovery of knee extensor endurance and submaximal exercise tolerance, as quantified on a self-powered treadmill, over 24 h in 18 patients (mean age 65 ± 3 years, functional class 2.4 ± 0.2, ejection fraction 23 ± 3%) and in 10 control subjects.Results.Peak oxygen consumption was reduced in both heart failure groups (15.4 ± 1.4 and 15.6 ± 1.0 ml/kg per min) compared with that in the respective control groups (23.1 ± 2.9 and 25.6 ± 1.0 ml/kg per min, both p < 0.05), as was muscle endurance but not muscle strength. In protocol 1, knee extensor endurance recovered more slowly in the patients than in control subjects (to 62 ± 4% and 87 ± 7% of the baseline value after 5 min, respectively, p < 0.05). In protocol 2, submaximal exercise tolerance was lower in the patients with heart failure than in control subjects (1,075 ± 116 vs. 1,390 ± 110 m), but knee extensor endurance and walking distance recovered fully by 10 and 30 min, respectively.Conclusions.Although these findings confirm earlier studies that demonstrated impaired muscle endurance in patients with heart failure, the results provide no evidence that recovery of either muscle function or submaximal exercise tolerance is delayed beyond the initial 5 to 10 min after exercise

Differences Between Primary Care Physicians and Cardiologists in Management of Congestive Heart Failure: Relation to Practice Guidelines 11This work was supported in part by unrestricted grants from Bristol-Myers Squibb Co., Princeton, New Jersey; Burroughs Wellcome Co., Research Triangle Park, North Carolina; Merck & Co., West Point, Pennsylvania; and the Department of Veterans Affairs Research Service.22All editorial decisions for this article, including selection of referees, were made by a Guest Editor. This policy applies to all articles with authors from the University of California in San Francisco.

AbstractObjectives. This study was designed to characterize physician practices in the management of congestive heart failure (CHF) and to determine whether these practices vary by specialty and how they relate to guideline recommendations.Background. Congestive heart failure is responsible for considerable mortality, morbidity and health care resource utilization. Although there have been important advances in the diagnostic evaluation and treatment of CHF, little information is available on physician practices in this area.Methods. We surveyed physicians concerning their management of patients with CHF. The results were analyzed in multivariate models to determine the relation of diagnostic and treatment approaches to physician specialty, time since training, board certification and volume of patients with CHF. Surveys were sent to a sample of 2,250 family and general practitioners (FP/GPs), internists and cardiologists. Responses were examined in relation to guidelines issued by the Agency for Health Care Policy and Research that had been released 9 months previously.Results. Significant differences were found between physician groups with regard to each of the major guideline recommendations. For example, routine evaluation of left ventricular function, a point of emphasis in the guideline, is performed by 87% of cardiologists, but by only 77% of internists and 63% of FP/GPs (p < 0.001 between groups). Angiotensin-converting enzyme inhibitors were used by cardiologists, internists and FP/GPs in 80%, 71% and 60% of patients with mild to moderate CHF, respectively (p < 0.001 between groups). Larger differences were reported in the prescribed dosages of these drugs and their use in patients with renal dysfunction.Conclusions. Cardiologists report practices more in conformity with published guidelines for CHF than do internists and FP/GPs. Because of the large numbers of patients with CHF and their substantial mortality, morbidity and cost of care, these differences may have a major impact on outcomes and health care costs

Importance of obesity, race and age to the cardiac structural and functional effects of hypertension

AbstractObjectives. The purpose of this study was to determine the effects of obesity and its interaction with age, race and the magnitude of blood pressure elevation in a large cohort of patients with mild to moderate hypertension and a high prevalence of left ventricular hypertrophy.Background. Obesity, race and age each have important effects on the incidence and severity of hypertension and may contribute to the effects of blood pressure elevation on the cardiac manifestations of hypertension.Methods. Left ventricular structure and function were assessed with two-dimensional targeted M-mode echocardiography in 692 men with mild to moderate hypertension (average blood pressure 153/100 mm Hg), and the data were compared in relation to obesity (determined from body mass index), age, race, blood pressure, physical activity, plasma renin activity, urinary sodium excretion, hematocrit, heart rate and serum lipids.Results. Left ventricular hypertrophy was common (630% with increased left ventricular mass, 22% with left ventricular hypertrophy on the electrocardiogram [ECG]). On multivariable regression analysis, body mass index was the strongest predictor of left ventricular mass and magnified the slope relation of blood pressure to left ventricular mass. Despite a greater prevalence of ECG left ventricular hypertrophy in blacks (31%) than in whites (10%), left ventricular mass and echocardiographic prevalence of left ventricular hypertrophy did not differ by race. However, septal, posterior left ventricular and relative wall thickness were greater in black than in white men.Conclusions. Obesity is the strongest clinical predictor of left ventricular mass and left ventricular hypertrophy la men, even in those with mild to moderate hypertension of sufficient severity to be associated with a high prevalence of left ventricular hypertrophy. Moreover, independent effects of systolic blood pressure on left ventricular mass an amplified by obesity. Although race does not affect left ventricular mass or the prevalence of left ventricular hypertrophy, black race is associated with greater relative wall thickness, itself a predictor of unfavorable cardiovascular outcome

The Irbesartan in Heart Failure With Preserved Systolic Function (I-PRESERVE) Trial: Rationale and Design

Background: Although 40% to 50% of patients with chronic heart failure (HF) have relatively preserved systolic function (PSF), few trials have been conducted in this population and treatment guidelines do not include evidence-based recommendations. Methods and Results: The Irbesartan in Heart Failure with Preserved Systolic Function (I-PRESERVE) is enrolling 4100 subjects with HF-PSF to evaluate whether 300 mg irbesartan is superior to placebo in reducing mortality and prespecified categories of cardiovascular hospitalizations. The principal inclusion criteria are age ≥60 years, heart failure symptoms, an ejection fraction ≥45%, and either hospitalization for heart failure within 6 months or corroborative evidence of heart failure or the substrate for diastolic heart failure. Additional secondary end points include cardiovascular mortality, cause-specific mortality and morbidity, change in New York Heart Association functional class, quality of life, and N-terminal pro-BNP measurements. Follow-up will continue until 1440 patients experience a primary end point. Substudies will evaluate changes in echocardiographic measurements and serum collagen markers. Conclusion: I-PRESERVE is the largest trial in this understudied area and will provide crucial information on the characteristics and course of the syndrome, as well as the efficacy of the angiotensin receptor blocker irbesartan

The Irbesartan in Heart Failure With Preserved Systolic Function (I-PRESERVE) Trial: Rationale and Design

Background: Although 40% to 50% of patients with chronic heart failure (HF) have relatively preserved systolic function (PSF), few trials have been conducted in this population and treatment guidelines do not include evidence-based recommendations. Methods and Results: The Irbesartan in Heart Failure with Preserved Systolic Function (I-PRESERVE) is enrolling 4100 subjects with HF-PSF to evaluate whether 300 mg irbesartan is superior to placebo in reducing mortality and prespecified categories of cardiovascular hospitalizations. The principal inclusion criteria are age ≥60 years, heart failure symptoms, an ejection fraction ≥45%, and either hospitalization for heart failure within 6 months or corroborative evidence of heart failure or the substrate for diastolic heart failure. Additional secondary end points include cardiovascular mortality, cause-specific mortality and morbidity, change in New York Heart Association functional class, quality of life, and N-terminal pro-BNP measurements. Follow-up will continue until 1440 patients experience a primary end point. Substudies will evaluate changes in echocardiographic measurements and serum collagen markers. Conclusion: I-PRESERVE is the largest trial in this understudied area and will provide crucial information on the characteristics and course of the syndrome, as well as the efficacy of the angiotensin receptor blocker irbesartan

Rolofylline, an adenosine A1−receptor antagonist, in acute heart failure

Background: Worsening renal function, which is associated with adverse outcomes, often develops in patients with acute heart failure. Experimental and clinical studies suggest that counterregulatory responses mediated by adenosine may be involved. We tested the hypothesis that the use of rolofylline, an adenosine A1−receptor antagonist, would improve dyspnea, reduce the risk of worsening renal function, and lead to a more favorable clinical course in patients with acute heart failure. Methods: We conducted a multicenter, double-blind, placebo-controlled trial involving patients hospitalized for acute heart failure with impaired renal function. Within 24 hours after presentation, 2033 patients were randomly assigned, in a 2:1 ratio, to receive daily intravenous rolofylline (30 mg) or placebo for up to 3 days. The primary end point was treatment success, treatment failure, or no change in the patient’s clinical condition; this end point was defined according to survival, heart-failure status, and changes in renal function. Secondary end points were the post-treatment development of persistent renal impairment and the 60-day rate of death or readmission for cardiovascular or renal causes. Results: Rolofylline, as compared with placebo, did not provide a benefit with respect to the primary end point (odds ratio, 0.92; 95% confidence interval, 0.78 to 1.09; P=0.35). Persistent renal impairment developed in 15.0% of patients in the rolofylline group and in 13.7% of patients in the placebo group (P=0.44). By 60 days, death or readmission for cardiovascular or renal causes had occurred in similar proportions of patients assigned to rolofylline and placebo (30.7% and 31.9%, respectively; P=0.86). Adverse-event rates were similar overall; however, only patients in the rolofylline group had seizures, a known potential adverse effect of A1-receptor antagonists. Conclusions: Rolofylline did not have a favorable effect with respect to the primary clinical composite end point, nor did it improve renal function or 60-day outcomes. It does not show promise in the treatment of acute heart failure with renal dysfunction. (Funded by NovaCardia, a subsidiary of Merck; ClinicalTrials.gov numbers, NCT00328692 and NCT00354458.

Aliskiren, enalapril, or aliskiren and enalapril in heart failure

BACKGROUND Among patients with chronic heart failure, angiotensin-converting–enzyme (ACE) inhibitors reduce mortality and hospitalization, but the role of a renin inhibitor in such patients is unknown. We compared the ACE inhibitor enalapril with the renin inhibitor aliskiren (to test superiority or at least noninferiority) and with the combination of the two treatments (to test superiority) in patients with heart failure and a reduced ejection fraction. METHODS After a single-blind run-in period, we assigned patients, in a double-blind fashion, to one of three groups: 2336 patients were assigned to receive enalapril at a dose of 5 or 10 mg twice daily, 2340 to receive aliskiren at a dose of 300 mg once daily, and 2340 to receive both treatments (combination therapy). The primary composite outcome was death from cardiovascular causes or hospitalization for heart failure. RESULTS After a median follow-up of 36.6 months, the primary outcome occurred in 770 patients (32.9%) in the combination-therapy group and in 808 (34.6%) in the enalapril group (hazard ratio, 0.93; 95% confidence interval [CI], 0.85 to 1.03). The primary outcome occurred in 791 patients (33.8%) in the aliskiren group (hazard ratio vs. enalapril, 0.99; 95% CI, 0.90 to 1.10); the prespecified test for noninferiority was not met. There was a higher risk of hypotensive symptoms in the combination-therapy group than in the enalapril group (13.8% vs. 11.0%, P=0.005), as well as higher risks of an elevated serum creatinine level (4.1% vs. 2.7%, P=0.009) and an elevated potassium level (17.1% vs. 12.5%, P&lt;0.001). CONCLUSIONS In patients with chronic heart failure, the addition of aliskiren to enalapril led to more adverse events without an increase in benefit. Noninferiority was not shown for aliskiren as compared with enalapri

Irbesartan in patients with heart failure and preserved ejection fraction

Background: Approximately 50% of patients with heart failure have a left ventricular ejection fraction of at least 45%, but no therapies have been shown to improve the outcome of these patients. Therefore, we studied the effects of irbesartan in patients with this syndrome. Methods: We enrolled 4128 patients who were at least 60 years of age and had New York Heart Association class II, III, or IV heart failure and an ejection fraction of at least 45% and randomly assigned them to receive 300 mg of irbesartan or placebo per day. The primary composite outcome was death from any cause or hospitalization for a cardiovascular cause (heart failure, myocardial infarction, unstable angina, arrhythmia, or stroke). Secondary outcomes included death from heart failure or hospitalization for heart failure, death from any cause and from cardiovascular causes, and quality of life. Results: During a mean follow-up of 49.5 months, the primary outcome occurred in 742 patients in the irbesartan group and 763 in the placebo group. Primary event rates in the irbesartan and placebo groups were 100.4 and 105.4 per 1000 patient-years, respectively (hazard ratio, 0.95; 95% confidence interval [CI], 0.86 to 1.05; P=0.35). Overall rates of death were 52.6 and 52.3 per 1000 patient-years, respectively (hazard ratio, 1.00; 95% CI, 0.88 to 1.14; P=0.98). Rates of hospitalization for cardiovascular causes that contributed to the primary outcome were 70.6 and 74.3 per 1000 patient-years, respectively (hazard ratio, 0.95; 95% CI, 0.85 to 1.08; P=0.44). There were no significant differences in the other prespecified outcomes. Conclusions: Irbesartan did not improve the outcomes of patients with heart failure and a preserved left ventricular ejection fraction. (ClinicalTrials.gov number, NCT00095238.)