ABSTRACTS FROM MEDICAL LITERATURE FOR THE GERIATRICS PRACTITIONER

ORAL ANTIPLATELETTHERAPY IN CVD, CAD, AND PAD
Atherothrombosis is a pathophysiologic process that results in clinical ischemic events affecting the cerebral, coronary, and peripheral arterial circulation. Antiplatelet agents, used alone or in combination, are effective in preventing recurrent vascular events among individuals with established vascular disease. The authors’ objective was to summarize the current state of evidence regarding oral antiplatelet treatment in patients with cerebrovascular disease (CVD), coronary artery disease (CAD), and peripheral arterial disease (PAD). Using the key terms acute coronary syndrome, atherothrombosis, ischemic stroke, myocardial infarction, MI, peripheral arterial disease, TIA, transient ischemic attack, unstable angina, aspirin, ticlopidine, dipyridamole, and clopidogrel, the authors searched the MEDLINE database as well as the trial register of the Cochrane Groups to identify studies published from 1960 to August 2004. They manually searched journals and abstract booklets; scrutinized reference lists of trials and review articles; and reviewed meta-analyses, scientific statements, and guidelines from official societies.

They found that appropriate oral first-line antiplatelet therapy is aspirin for individuals with ST-segment elevation myocardial infarction; aspirin or clopidogrel for those with TIA or stroke, chronic stable angina, or peripheral arterial disease; and aspirin combined with clopidogrel for those with non–ST-segment elevation acute coronary syndrome. Aspirin combined with dipyridamole is a possible alternative for patients who experience a first episode of TIA or stroke in the absence of clinically apparent CAD. Although ticlopidine has been shown to be of benefit in various vascular conditions, its adverse-effect profile has limited its use. The authors concluded that aspirin, ticlopidine, clopidogrel, aspirin combined with clopidogrel, and aspirin combined with dipyridamole are effective in preventing recurrent vascular events among various subgroups of patients with vascular disease. Current clinical trial evidence favors the use of aspirin or clopidogrel as first-line agents for the majority of patients with vascular disease. Clinical trials evaluating combination antiplatelet therapies will direct future practice.

Tran H, Anand SS. Oral antiplatelet therapy in cerebrovascular disease, coronary artery disease, and peripheral arterial disease. JAMA 2004;292:1867-1874.

MAINTAINING SINUS RHYTHM IN ATRIAL FIBRILLATION
Recent studies have indicated that outcomes in patients with atrial fibrillation who are managed with rate control and anticoagulation are similar to those in patients who have maintenance of sinus rhythm. These studies did not include important groups of patients with atrial fibrillation in whom anti-arrhythmic therapy may be appropriate. This perspective argues for the maintenance of sinus rhythm and for the use of antiarrhythmic therapy that includes medications, invasive procedures, and a combination of both in appropriate patients.

Zimetbaum P, Josephson ME. Is there a role for maintaining sinus rhythm in patients with atrial fibrillation? Ann Intern Med 2004;141:720-726.

RHYTHM VERSUS RATE CONTROL IN ATRIAL FIBRILLATION
Atrial fibrillation is the most common type of sustained cardiac arrhythmia, but recent trials have identified no clear advantage of rhythm control over rate control. Consequently, economic factors often play a role in guiding treatment selection.

The authors performed a retrospective economic evaluation to estimate the cost-effectiveness of rhythm-control versus rate-control strategies for atrial fibrillation in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM). They compiled data on survival and obtained use of health care resources were for all 4060 AFFIRM participants. Unit costs were estimated from various U.S. databases. The target population was patients with atrial fibrillation who were 65 years of age or who had other risk factors for stroke or death, similar to those enrolled in AFFIRM. Mean follow-up was 3.5 years. They compared management of patients with atrial fibrillation with antiarrhythmic drugs (rhythm control) compared with drugs that control heart rate (rate control). Outcome measures were mean survival, resource use, costs, and cost-effectiveness. A mean survival gain of 0.08 year (P = 0.10) was observed for rate control. Patients in the rate-control group used fewer resources (hospital days, pacemaker procedures, cardioversions, and short-stay and emergency department visits). Rate control cost $5077 less per person than rhythm control. Results of sensitivity analysis showed that cost savings ranged from $2189 to $5481 per person. Rhythm control was more costly and less effective than rate control in 95% of the bootstrap replicates over a wide range of cost assumptions. Resource use was limited to key items collected in AFFIRM, and the results are generalizable only to similar patient populations with atrial fibrillation. The investigators concluded that rate control is a cost-effective approach to the management of atrial fibrillation compared with maintenance of sinus rhythm in patients with atrial fibrillation similar to those enrolled in AFFIRM.

Marshall DA, Levy AR, Vidaillet H, et al, and the AFFIRM and CORE Investigators. Cost-effectiveness of rhythm versus rate control in atrial fibrillation. Ann Intern Med 2004; 141:653-661.

TOPICAL NSAIDS FOR OSTEOARTHRITIS
This meta-analysis sought to assess the efficacy of topical non-steroidal anti-inflammatory drugs (NSAIDs) in the treatment of osteoarthritis. Data sources used were MEDLINE, Embase, Scientific Citation Index, CINAHL, Cochrane Library, and abstracts from conferences. Inclusion criterion was randomised controlled trials comparing topical NSAIDs with placebo or oral NSAIDs in osteoarthritis. Effect size was calculated for pain, function, and stiffness. Rate ratio was calculated for dichotomous data such as clinical response rate and adverse event rate. Number needed to treat to obtain the clinical response was estimated. Quality of trial was assessed, and sensitivity analyses were undertaken. The meta-analysis found that topical NSAIDs were superior to placebo in relieving pain due to osteoarthritis only in the first 2 weeks of treatment. Effect sizes for weeks 1 and 2 were 0.41 (95% confidence interval, 0.16 to 0.66) and 0.40 (0.15 to 0.65), respectively. No benefit was observed over placebo in weeks 3 and 4. A similar pattern was observed for function, stiffness, and clinical response rate ratio and number needed to treat. Topical NSAIDs were inferior to oral NSAIDs in the first week of treatment and associated with more local side effects such as rash, itch, or burning (rate ratio 5.29, 1.14 to 24.51). The authors concluded that randomised controlled trials of short duration only (less than 4 weeks) have assessed the efficacy of topical NSAIDs in osteoarthritis. After 2 weeks there was no evidence of efficacy superior to placebo. No trial data support the long term use of topical NSAIDs in osteoarthritis.

Lin J, Zhang W, Jones A, Doherty M. Efficacy of topical non-steroidal anti-inflammatory drugs in the treatment of osteoarthritis: Meta-analysis of randomised controlled trials. BMJ 2004;329:324.