Julian W.E. Jarman, MBBS, MRCP, St. Mary’s Hospital and Imperial College, London, UK.
Tom Wong, MBChB, MRCP, St. Mary’s Hospital and Imperial College, London, UK.

The prevalence of cardiac arrhythmia increases within a continuously aging population. This is illustrated by the projection of a 2.5-fold increase in the number of cases of atrial fibrillation (AF) in the United States by 2050. Approaches to arrhythmia management have changed considerably in recent years; this is, in part, related to the better understanding of effects of the existing drug therapy in patients with arrhythmia, and the advances of catheter ablation and complex device therapies for selected older patients.
In this review, we have broadly classified arrhythmias into brady- and tachyarrhythmias (AF, paroxysmal supraventricular tachycardias, and ventricular arrhythmias) and followed by highlighting the contemporary therapies for these arrhythmias in older adults.
Key words: aging, arrhythmia, drug, ablation, devices.

Sophie Jamal, MD, FRCPC, Osteoporosis Research Fellow, Sunnybrook and Women's College Health Sciences Centre, Toronto, ON.

Osteoporosis, defined as a reduction in bone mass leading to an increased susceptibility to fracture with minimal trauma, affects 1.4 million Canadians.¹ Osteoporotic hip and vertebral fractures are major causes of disability and premature death. For example, the average length of stay in an acute care hospital after a hip fracture is three weeks, and one in four patients must remain in long-term care institutions for at least one year. Furthermore, patients with hip and vertebral fractures face a 20% increased risk of mortality.² Osteoporosis is also costly--in Canada, in 1993, the total expenditure for fractures was estimated to be 1.3 billion dollars.³ As the population of Canada ages, the impact of osteoporosis will increase. As such, health care providers should be aware of techniques to prevent fractures due to osteoporosis.

In addition to encouraging physical activity and ensuring adequate calcium and vitamin D intake, several medications can be used to prevent osteoporotic fractures. These drugs, which have been studied predominantly in postmenopausal women, include bisphosphonates, estrogen, selective estrogen receptor modulators and calcitonin. The evidence that supports the use of these agents to prevent bone loss and fractures in postmenopausal women is reviewed below.

A Review of Efficacy, Toxicity and Safety Considerations

Charles L Bennett, MD, PhD
The Chicago VA Healthcare
System/Lakeside Division, the Robert H Lurie Comprehensive Cancer Center and
the Division of Hematology/Oncology of the Department of Medicine,
Northwestern University,
Chicago, IL, USA.

Richard H Bennett, MD
Department of Neurology,
Albert Einstein Northern Hospital and
the Medical School of the University of Pennsylvania,
Philadelphia, PA, USA.

Introduction
Stroke is a common cause of morbidity and mortality in older adults in the United States and Canada. Fortunately, in both countries, the age-adjusted national death rate for stroke has declined, reflecting increasingly widespread use of primary and secondary prophylaxis efforts. The mainstay of stroke prevention is the use of antiplatelet agents which interfere with thrombus formation by platelets in diseased or damaged blood vessels (see Figure 1). While aspirin has been the primary antiplatelet agent, over the past ten years, ticlopidine (Ticlid), clopidogrel (Plavix) and extended release dipyridamole plus aspirin (Aggrenox) have been approved for use in this setting.

The Mayo Clinic has reported that patients taking a commonly prescribed treatment for colon cancer are dying at almost three times the rate of patients who took other medications for the same disease. The chemotherapy drug, irinotecan, has been shown to increase life expectancy by about two months for patients with advanced colorectal cancer. However, in the first two months of receiving the drug, 33 out of 1,199 patients died, among patients taking different drugs, only 10 out of 905 patients died within the same period.

The drug is manufactured by Pharmacia and marketed under the name Camptosar. Although the findings are preliminary and not statistically significant, the company has sent letters to doctors in the US advising them of the results. The finding is somewhat controversial, as this effect of the drug has not been seen previously. However, the research group at the Mayo Clinic explains that this may result from the fact that the deaths were spread out among different medical centres, and when data were pooled the effect was seen; it might not have been obvious to individual physicians. Doctors who are conducting the study will be giving the drug in lower doses and will be more aggressive about looking for warning signs of toxicity, including diarrhea, nausea, vomiting and a low white blood cell count.

The results of the study will be published in a letter in an upcoming issue of the New England Journal of Medicine.

Barry Goldlist, MD, FRCPC, FACP

The issue of drug use in the elderly is extraordinarily important. All physicians know that medications in older patients are a two edged sword: the elderly have many more diseases that potentially benefit from medications, but they are also prone to more adverse effects from those same medications. The increased burden of disease in the elderly is the major reason for the high drug utilization in the elderly, but in the clinical practice of geriatric medicine, it is almost as common to see potentially beneficial medications withheld, as it is to see unnecessary polypharmacy. Of the many reasons for this, I would like to discuss two physician-related factors, excessive fear of side effects, and a flawed understanding of cost effectiveness.

There is no doubt that the elderly are prone to drug side effects. However, withholding effective treatment because of a fear of side effects is often an example of flawed reasoning. All treatments, regardless of the age of the patient, require that the risks and benefits are evaluated and a judgement regarding the balance is then made. To withhold anticoagulants from an elderly patient with atrial fibrillation because age increases the risk of bleeding is assessing only one side of the equation. The number of strokes prevented by anticoagulation is greater in older patients, and if anything the risk/benefit ratio is more favorable for seniors. Similarly, withholding anticoagulants because a patient has fallen once or twice, means a definite benefit is lost to prevent a theoretical complication of traumatic bleeding. Current evidence does not warrant the common perception that recurrent falls are an absolute contraindication to anticoagulation.

Many new pharmaceuticals are quite expensive, and there is a feeling among some physicians that they are too expensive for the elderly. While pharmacoeconomics is a crucial new discipline, none of the experts in the field would eliminate the elderly from potentially beneficial treatments. Decisions not to use expensive medications when cheaper efficacious therapies are available are an appropriate approach regardless of age. Once again, because of the higher event rates for the elderly, treatments are generally more cost effective in the elderly. The best example of this is the use of thrombolytic therapy in those over 70. The cost per life year saved is much less in the elderly than in younger patients with myocardial infarction.

In summary, we do want to avoid polypharmacy in the elderly, and the prescribing cascade that can result, as more drugs are prescribed to relieve side effects of prior medications. However, it is just as important to ensure that therapies of proven value are not withheld from older patients.