Heart failure: the Cinderella of cardiology?

Profile of St. Jude Medical's Allure Quadra quadripolar pacemaker system for cardiac resynchronization therapy

Congestive heart failure is a major public health epidemic and economic burden in the USA and worldwide. Cardiac resynchronization therapy is an effective therapy for treating congestive heart failure in conjunction with pharmacologic therapy. The average congestive heart failure admission costs approximately US$ 8 billion annually. Current cardiac resynchronization therapy pacemaker systems from various manufacturers deliver therapy-utilizing bipolar leads including the left ventricle, with electrode spacing ranging from 8 to 22 mm. The Quartet LV™ lead model 1458Q (St. Jude Medical Sylmar, CA) is a quadripolar lead with a 4.0 Fr. tip electrode and three 4.7 Fr. ring electrodes located 20, 30 and 47 mm from the tip. The Quartet lead and Allure Quadra TM allows 14 pacing configurations, providing benefits, including reductions in phrenic nerve stimulation, reduced pacing thresholds, improved battery longevity and potential reductions, in non-responders to cardiac resynchronization therapy. In addition, there is cost benefit data from utilizing quadripolar technology compared with traditional bipolar cardiac resynchronization therapy.

Influence of sex on treatment and outcome in chronic heart failure

The population is aging, the prevalence of heart failure increases with age, and on average women live longer than men. There is evidence for sex-specific effects of individual, guideline-recommended drugs used for treatment of chronic heart failure. Women are underrepresented in most clinical trials and only a minority of drug applications to regulatory authorities have included sex analyses. The present review focuses on the potential female survival benefit in heart failure, the influence of sex on medical treatment in a broader sense, and the potential benefit to be derived from guideline recommended treatment and common adjunctive heart failure medication.

Utility of brain natriuritic peptide as a diagnostic tool for congestive heart failure in the elderly

We studied the performance characteristics of B-type natriuretic peptide (BNP) as a diagnostic test for congestive heart failure in the elderly dyspneic population. In a retrospective chart review study, dyspneic patients who had a BNP level drawn were included. To diagnose congestive heart failure (CHF), the Framingham Criteria were used. To diagnose pneumonia or a lower respiratory tract infection, the consensus development conference Criteria for Pneumonia/Lower Respiratory Tract Infection were used. Based on the criteria satisfied, the patients were categorized into one of 4 groups: group 1, pneumonia/lower respiratory tract infection; group 2, CHF; group 3, both; group 4, neither. Sensitivity, specificity, and positive and negative likelihood ratios were calculated for various BNP reference limits from 100 pg/ml upwards in increments of 100. A total of 70 patients (mean age 76.5) presenting with dyspnea were included in the study. Forty-six were females. The mean (+/-SD) BNP level for group 1 (n = 13) was 273 (+/-360) pg/ml, for group 2 (n = 30) it was 1394 (+/-934) pg/ml, for group 3 (n = 17) it was 1138 (+/-842) pg/ml, and for group 4 (n = 10) it was 403 (+/-362) pg/ml. Forty-seven patients (groups 2 and 3) met the Framingham criteria (CHF+). The other 23 (groups 1 and 4) did not (CHF-). The sensitivity and specificity of BNP for CHF at a cutoff of 100 pg/ml was 96% and 26%, respectively. The sensitivity (87%) and specificity (74%) were optimal at a cutoff of 400 pg/ml. Our study indicates that the specificity of a BNP level of > or = 100 pg/ml for diagnosing CHF in the elderly is poor. Our data suggest an optimal BNP value of > or = 400 pg/ml. Elderly patients frequently have multiple etiologies contributing to dyspnea. In our study, one-fourth of the patients satisfied the criteria for a dual diagnosis of CHF and pneumonia.

The economic burden of heart failure

Heart failure, a major cause of morbidity and mortality among the elderly, is a serious public health problem. As the population ages and the prevalence of heart failure increases, expenditures related to the care of these patients will climb dramatically. As a result, the health care industry must develop strategies to contain this staggering economic burden. Strategies may include adopting approaches for preventing heart failure and implementing new treatment modalities with proven efficacy into large-scale clinical practice. Successful implementation of these strategies will require intensive physician and patient education and development of innovative approaches to fund support services.

Epidemiology of congestive heart failure in three ethnic groups

Congestive heart failure (CHF) is a leading cause of morbidity, disability, and mortality in old age, but little is known about the epidemiology of this condition in free-living minority populations. To determine the prevalence of CHF and associated risk factors in a multiethnic community, a population sample of 2759 elderly (i.e., 65 years of age and older) African American (AA), Hispanic-Cuban (HC), and white non-Hispanic (WNH) men and women from Miami-Dade County, Florida, were examined. There were 153 (5.6%) cases of self-reported CHF in the sample. The unadjusted prevalence rate of CHF was virtually identical among elderly AA (4.8%) and WNH (4.9%) but was significantly (p=0.04) lower than the rate among HC (6.8%). Sex- and ethnic-specific analyses showed that the highest prevalence rate of CHF was among HC women (8.2%). A multiple logistic analysis was used to calculate the odds ratio (OR) and 95% confidence interval (CI) of CHF in relation to age, sex, ethnicity, medical history, and smoking and alcohol drinking habits. Age (65-74 vs. 75-84; OR 1.7; CI 1.2-2.4; p=0.01), HC ethnic group (OR 1.5; CI 1.0-2.4; p=0.05), history of hypertension (OR 1.5; CI 1.1-2.1; p=0.02), history of myocardial infarction (OR 2.3; CI 1.5-3.5; p=0.0001), and history of diabetes mellitus (OR 1.9; CI 1.3-2.8; p=0.001) were directly, significantly, and independently associated with the prevalence of self-reported CHF. The findings here confirm those of prior studies in elderly white US residents, which indicate that heart attack, hypertension, and diabetes mellitus are major risk factors for CHF. The results also show that elderly AA and WNH have similar CHF prevalence rates. The higher CHF prevalence in elderly HC women found in this study requires further investigation. (c)2001 by CHF, Inc.

Prevalence and clinical characteristics of left ventricular dysfunction among elderly patients in general practice setting: cross sectional survey

OBJECTIVE

To assess the prevalence and clinical characteristics of left ventricular dysfunction among elderly patients in the general practice setting by echocardiographic assessment of ventricular function.

DESIGN

Cross sectional survey.

SETTING

Four centre general practice in Poole, Dorset.

SUBJECTS

817 elderly patients aged 70-84 years.

MAIN OUTCOMES

Echocardiographic assessment of left ventricular systolic function including measurement of ejection fraction by biplane summation method where possible, clinical symptoms, and signs of left ventricular dysfunction.

RESULTS

The overall prevalence of left ventricular systolic dysfunction was 7.5% (95% confidence interval 5.8% to 9.5%); mild dysfunction (5.0%) was considerably more prevalent than moderate (1.6%) or severe dysfunction (0.7%). Measurement of ejection fraction was possible in 82% of patients (n=667): in patients categorised as having mild, moderate, or severe dysfunction, the mean ejection fraction was 48% (SD 12.0), 38% (8.1), and 26% (7.9) respectively. At all ages the prevalence was much higher in men than in women (odds ratio 5.1, 95% confidence interval 2.6 to 10.1). No clinical symptom or sign was both sensitive and specific. In around half the patients with ventricular dysfunction (52%, 32/61) heart failure had not been previously diagnosed.

CONCLUSIONS

Unrecognised left ventricular dysfunction is a common problem in elderly patients in the general practice setting. Appropriate treatment with angiotensin converting enzyme inhibitors has the potential to reduce hospitalisation and mortality in these patients, but diagnosis should not be based on clinical history and examination alone. Screening is feasible in general practice, but it should not be implemented until the optimum method of identifying left ventricular dysfunction is clarified, and the cost effectiveness of screening has been shown.