Cochrane for Clinicians

Putting Evidence into Practice

This clinical content conforms to AAFP criteria for evidence-based continuing medical education (EB CME). EB CME is clinical content presented with practice recommendations supported by evidence that has been systematically reviewed by an AAFP-approved source. The practice recommendations in this activity are available online at http://www.cochrane.org/cochrane/revabstr/AB001800.htm.

The Cochrane Abstract below is a summary of a review from the Cochrane Library. It is accompanied by an interpretation that will help clinicians put evidence into practice. Jasmine Chen Gatti, M.D., presents a clinical scenario and question based on the Cochrane Abstract, along with the evidence-based answer and a full critique of the abstract.

Exercise-Based Rehabilitation for Coronary Heart Disease

JASMINE CHEN GATTI, M.D.
Hebrew Home of Greater Washington, Rockville, Maryland

Clinical Scenario

A 59-year-old man is admitted to the critical care unit and diagnosed with a myocardial infarction (MI). After an uneventful course, he is discharged to follow up with his family doctor.

Clinical Question

Does a comprehensive cardiac rehabilitation program or exercise-based cardiac rehabilitation program improve outcomes in patients with MI, coronary bypass graft, percutaneous transluminal coronary angioplasty, angina, or coronary artery disease?

Evidence-Based Answer

Cardiac rehabilitation based on exercise alone and comprehensive cardiac rehabilitation reduce all-cause mortality by about one third. It is unclear which type of rehabilitation is more beneficial.

Cochrane Abstract Background. The burden of cardiovascular disease worldwide is one of great concern to patients and health care agencies. Cardiac rehabilitation aims to restore patients with heart disease to health through exercise alone or comprehensive cardiac rehabilitation. Objectives. To determine the effectiveness of exercise alone or exercise as part of a comprehensive cardiac rehabilitation program on the mortality, morbidity, health-related quality of life, and modifiable cardiac risk factors in patients with coronary heart disease. Search Strategy. The authors1 searched electronic databases for randomized, controlled trials using standardized trial filters, from the earliest date available to December 31, 1998. Selection Criteria. Selected patients were men and women of all ages, in hospital or community settings, who had myocardial infarction, coronary artery bypass graft, or percutaneous transluminal coronary angioplasty, or who have angina pectoris or coronary artery disease (CAD) defined by angiography. Data Collection and Analysis. Studies were selected independently by two reviewers, and data were extracted independently. Authors were contacted when possible to obtain missing information. Primary Results. This systematic review increased the number of patients from approximately 4,500 in earlier meta-analyses to 8,440 (7,683 who contributed to the total mortality outcome). The pooled effect estimate for the total mortality for the exercise-only intervention shows a 27 percent reduction in all-cause mortality (random effects model odds ratio [OR], 0.73; 95 percent confidence interval [CI], 0.54 to 0.98). Comprehensive cardiac rehabilitation reduced all-cause mortality, but to a lesser degree (OR, 0.87; 95 percent CI, 0.71 to 1.05). Total cardiac mortality was reduced by 31 percent (random effects model OR, 0.69; 95 percent CI, 0.51 to 0.94) and 26 percent (random effects model OR, 0.74; 95 percent CI, 0.57 to 0.96) in the exercise-only and comprehensive cardiac rehabilitation groups, respectively. The authors found no evidence of an effect on the occurrence of nonfatal MI. There was a significant net reduction in total cholesterol level (pooled weighted mean difference [WMD] random effects model, -22.0 mg per dL [-0.57 mmol per L]; 95 percent CI, -0.83 to -0.31) and low-density lipoprotein (LDL) cholesterol level (pooled WMD random effects model, 19.7 mg per dL [-0.51 mmol per L]; 95 percent CI, -0.82 to -0.19) in the comprehensive cardiac rehabilitation group. Reviewers' Conclusions. Exercise-based cardiac rehabilitation is effective in reducing cardiac deaths. It is not clear from this review whether an exercise-only or comprehensive cardiac rehabilitation intervention is more beneficial. The study population is predominantly male, middle-aged, and with low risk factors. The ethnic origin of the participants was seldom reported. It is possible that patients who would have benefited most from the intervention were excluded from the trials on the basis of age, sex, or comorbidity.

These summaries have been derived from Cochrane reviews published in the Cochrane Database of Systematic Reviews in The Cochrane Library. Their content has, as far as possible, been checked with the authors of the original reviews, but the summaries should not be regarded as an official product of the Cochrane Collaboration; minor editing changes have been made to the text (www.cochrane.org).

Practice Pointers

Adult cardiac disease is the leading cause of morbidity and mortality in the United States. Although CAD rates are declining, it remains one of the leading causes of disability (approximately 19 percent of all conditions). Of 1 million U.S. survivors of acute MI, only about 10 to 15 percent make use of cardiac rehabilitation programs, which cost an estimated $160 to $240 million annually.1

The goals of cardiac rehabilitation are simply to restore and improve cardiac function, diminish disability, improve cardiac conditioning, and identify and modify cardiac risk factors. There was a wide variation in exercise-only programs. Some lasted as little as six months, while others lasted five years. The interventions included everything from mailed information on diet and exercise to daily exercise and support groups, and four-stage interventions lasting 30 months that included inpatient stays. In comprehensive programs for secondary prevention, techniques for blood pressure control, smoking cessation, lipid lowering, and diabetes control are addressed. Modifiable risk factors include smoking, hypertension, high low-density lipoprotein cholesterol levels, hypercholesterolemia, abdominal obesity, hypertriglyceridemia, hyperinsulinemia, diabetes, and sedentary lifestyle. The irreversible risk factors include male sex, family history of premature heart disease, age, and history of coronary artery disease, occlusive peripheral vascular disease, and cardiovascular disease.2

Although exercise-only rehabilitation and comprehensive cardiac rehabilitation reduced mortality, neither had an effect on recurrent, nonfatal MI, or rates of percutaneous transluminal coronary angioplasty and revascularization. There was a trend toward reduced all-cause mortality in patients in exercise-based programs compared with more comprehensive programs. There were insufficient data to determine if exercise-only programs are significantly better. Furthermore, most of the patients were middle-aged, low-risk men. In this population, it is reasonable to recommend exercise-based cardiac rehabilitation for patients with coronary artery disease.

The Author

Jasmine Chen Gatti, M.D., is a geriatrician setting up a home visit program at Hebrew Home of Greater Washington, Rockville, Md. Dr. Gatti completed a fellowship and worked as a consultant at the Australasian Cochrane Collaboration.

Address correspondence to Jasmine Chen Gatti, M.D., Hebrew Home of Greater Washington, 6121 Montrose Rd., Rockville, MD 20852-4856. (e-mail: gatti@hebrew-home.org). Reprints are not available from the author.

References

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Cochrane Briefs

Antihistamines for the Common Cold

Clinical Question

How effective are antihistamines for treatment of the common cold?

Evidence-Based Answer

Antihistamines are of minimal to no benefit as monotherapy for the common cold, and first-generation antihistamines may increase sedation in patients with a cold. Antihistamine-decongestant combinations reduce nasal symptoms and improve the recovery rate in older children and adults, but these combinations are not effective in younger children.

Practice Pointers

Although antihistamines are widely used in the treatment of the common cold, particularly as part of decongestant-antihistamine combinations, there is little evidence of benefit. De Sutter and colleagues reviewed 22 randomized, controlled trials (RCTs) of antihistamines as monotherapy and 13 RCTs of antihistamines combined with another medication, usually a decongestant. Most studies excluded patients with allergic rhinitis.

There was some evidence of a small beneficial effect of first-generation antihistamines as monotherapy for rhinorrhea and sneezing and a small short-term benefit in terms of overall recovery (number needed to treat, 14). However, more patients taking a first-generation antihistamine experienced sedation (7.9 versus 4.4 percent; absolute risk increase, 3.5 percent; number needed to harm, 29). No studies found a benefit for second-generation, nonsedating antihistamines.

Antihistamine-decongestant combinations were not effective in younger children but did improve general recovery and nasal symptoms in older children and adults. However, the latter studies did not report the magnitude of benefit, so it was difficult to tell if the benefit was clinically and not just statistically significant. Of course, the benefit may have been largely due to the decongestant alone.

MARK H. EBELL, M.D., M.S.

De Sutter AI, et al. Antihistamines for the common cold. Cochrane Database Syst Rev 2003;3:CD001267.

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