Exercise training and heart failure: a systematic review of current evidence

Chronic heart failure (CHEF) is a growing public health problem. Current guidelines provide detailed information regarding pharmacotherapy but little guidance about the value of exercise/cardiac rehabilitation programmes for individuals with this condition. To investigate the effects of exercise training upon CHF patients, a systematic literature review was carried out of trials (from 1966 to December 2000) which used as their main outcome measures the effects of exercise training upon: (a) physical performance; or (b) quality of life; or (c) morbidity/mortality. Databases searched include: MedLine; Science Citation Index; Social Sciences Citation Index; BIDS, Bandolier; Cochrane Database of Systematic Reviews (CDSR); NHS National Research Register (NRR); and Current Research in Britain (CRIB). Relevant bibliographic references from identified articles were also reviewed. Thirty-one trials were identified, comprising randomised controlled trials (RCTs) (14/31), randomised crossover trials (8/31), non-RCTs (2/31), and pre-test/post-test (7/31). Sample sizes were: 25 participants or fewer (20/31); 26 to 50 participants (7/31); 51 to 150 participants (4/31). Participants were predominantly younger with a mean age in 23/31 studies of 65 years or less, and male. Patients with comorbidities were often excluded. Positive effects were reported on physical performance (27/31), quality of life (11/16), mortality (1/31), and readmission rates (1/31). No cost-effectiveness analyses were identfied. We conclude that short-term physical exercise training in selected subgroups of patients with CHF has physiological benefits and positive effects on quality of life. This review highlights the continuing problem of clinical trials that include participants who are not representative of the general population of CHF patients seen in primary care. Further investigation of the utility and applicability of exercise training is essential.

A review of telemedicine cost-effectiveness studies

As interest in telemedicine grows, many of its proponents and vendors increasingly suggest that it is now time to move to full-scale implementation of telemedicine services in a variety of contexts throughout the world, and question the need for further evidence of its utility and cost-effectiveness. We have reviewed the published literature relating to cost-effectiveness studies in telemedicine and have identified some important weaknesses. Ten recommendations regarding the design of economic evaluations of telemedicine are suggested.

The role of telecare in the management of exacerbations of chronic obstructive pulmonary disease in the home

We examined home care as an alternative to hospital admission in exacerbations of chronic obstructive pulmonary disease (COPD). We performed a pilot study to investigate the feasibility of using telecommunications technology to assist in the support of acutely ill patients with exacerbations of COPD at home. Realtime, interactive video, via an analogue video-phone, was used to allow patients in their own homes to obtain nursing support from a nurse located at a distant base station. Six individuals, four male and two female, had video-phones installed in their homes by members of the nursing intervention team. The age range was 52-72 years, mean 61.5. These patients used the system on 18 occasions. Experience in home telecare, via interactive video, has been limited to provision of ongoing support for relatively stable individuals with chronic illness. This pilot project represents the first attempt at providing home telecare in the UK to those experiencing an acute exacerbation of their chronic illness, who would otherwise have merited acute hospital admission.

Clinical applications of thrombolytic therapy

Although thrombolytic therapy is used in a variety of settings, it has gained the most prominence in the treatment of myocardial infarction. The effectiveness of thrombolytic agents in reducing mortality in patients who present with myocardial infarction has been clearly demonstrated by large-scale studies. Unfortunately, only a minority of patients who present with myocardial infarction are currently receiving thrombolytic therapy. Many patients who could benefit from thrombolysis are unnecessarily excluded from treatment. It is now recommended that all patients who have appropriate electrocardiographic changes and present within 12 hours of the onset of acute myocardial infarction be considered for thrombolytic therapy. Factors such as age and history of previous myocardial infarction are no longer viewed as barriers to treatment.

Management of heart failure

Heart failure is associated with high rates of morbidity and mortality. Because heart failure is difficult to diagnose accurately on the basis of the history and physical examination alone, It is vital that clinical evaluation such as echocardiography be used to confirm the diagnosis. In addition, it is important to identify etiologic or predisposing factors that may be reversible. Angiotensin-converting enzyme inhibitors should be considered in all patients with a diagnosis of left ventricular systolic dysfunction, unless contraindications exist. Diuretics and digoxin are helpful in specific circumstances. Comorbid factors such as excessive alcohol intake and coronary artery insufficiency should be addressed. Patient and family education and cooperation with medical regimens can reduce morbidity and mortality.

Prevalence, aetiology and management of heart failure in general practice

BACKGROUND

There is a high level of morbidity and mortality among patients with heart failure. Management of the condition has changed substantially in recent years. However, there is little information on the management of heart failure in general practice.

AIM

A study was carried out in 1994 to assess the prevalence, aetiology and management of heart failure in a general practice setting.

METHOD

A retrospective review was undertaken of the manual and computerized medical records of patients in two group practices in Liverpool (combined patient population of 17 400).

RESULTS

A total of 266 patients with heart failure were identified (a prevalence of 15 per 1000). The two practices had 2747 patients who were aged 65 years and over and 221 of these had heart failure (prevalence of 80 per 1000). The principal aetiological factor considered responsible for heart failure was: coronary heart disease in 45% of patients, hypertension 18%, valve disease 9%, cor pulmonale 7%, cardiomyopathy 2% and a metabolic problem 2% (aetiology unknown in 17% of cases). Urea and electrolytes had been checked in the last year in 59% of patients. Chest x-ray and electrocardiography had been performed in 89% and 80% of patients, respectively, and echocardiography in 30%. Angiotensin converting enzyme (ACE) inhibitors were being prescribed to 33% of patients.

CONCLUSION

The study found a high prevalence of heart failure among patients aged 65 years and over. Coronary heart disease was considered to be the main aetiological factor. Patients were being investigated mainly by means of chest x-ray and electrocardiography. Most patients with heart failure were not receiving treatment with ACE inhibitors. Evaluation of heart failure by clinical criteria alone is now deemed insufficient. Echocardiography should be used routinely to assess cardiac dysfunction. Patients with confirmed left ventricular dysfunction will benefit from treatment with ACE inhibitors unless contraindications exist. The study suggests that there is a need to explore ways of optimizing the management of patients with heart failure.

Pharmacokinetics of human insulin zinc suspension (recombinant DNA) in normal man: a comparison with porcine insulin zinc suspension

A single dose crossover study in 10 fasting, non-diabetic men compared the 24-hour profiles of blood glucose, plasma insulin, and C-peptide following a single subcutaneous injection of either human insulin zinc suspension crystalline (recombinant DNA), or highly purified porcine insulin zinc suspension (mixed), in a standard dose of 0.2 U/kg. Both insulins produced moderate hypoglycaemia within 3 hours which persisted for 24 hours after administration. The rate of fall of blood glucose was similar from 0-3 hours but was significantly lower after the porcine insulin at 4 and 7 hours (p less than 0.05). Mean plasma insulin values were higher after porcine insulin between 2 and 6 hours (p less than 0.05) and a biphasic pattern was observed following injection of both insulins. Plasma C-peptide declined after each insulin was administered, and was significantly lower between 2 and 7 hours after porcine insulin. The duration of the hypoglycaemic action of human crystalline insulin (recombinant DNA), assessed by blood glucose measurements and C-peptide suppression, was equivalent to porcine insulin zinc suspension (mixed) (Monotard MC, Novo) over 24 hours.