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In This Issue of Archives of Internal Medicine
Arch Intern Med. 2002;162:505.
Balancing the Risks of Stroke and Upper Gastrointestinal Tract Bleeding
in Older Patients With Atrial Fibrillation
Persons with atrial fibrillation are at increased risk of thromboembolic
stroke; long-term antithrombotic therapy (warfarin sodium or aspirin) reduces
this risk. Balanced against this benefit is the risk of antithrombotic-associated
upper gastrointestinal (GI) tract bleeding complications. Thus, many physicians
are reluctant to prescribe antithrombotic therapy to older patients with atrial
fibrillation whom they deem at increased risk of major upper GI tract hemorrhage.
Using Markov decision analytic modeling, this study determined how factors
that increase the risk of major upper GI tract hemorrhage should influence
the choice of antithrombotic therapy in older patients with atrial fibrillation.
For 65-year-old patients with average risks of stroke and upper GI tract bleeding,
warfarin therapy was associated with 12.2 quality-adjusted life-years (QALYs)
per patient; aspirin therapy, 10.8 QALYs; and no antithrombotic therapy, 10.1
QALYs. For persons with significantly higher risks of upper GI tract bleeding
and/or lower risks of stroke, warfarin was no longer clearly the optimal antithrombotic
therapy (eg, for 80-year-old persons with a baseline risk of stroke of 4.3%
per year and concurrently taking a conventional nonsteroidal anti-inflammatory
drug: warfarin, 7.44 QALYs; aspirin, 7.39 QALYs; and no treatment, 7.21 QALYs).
Thus, for older patients with atrial fibrillation and factors that place them
at higher than average risk of upper GI tract bleeding, the optimal choice
of antithrombotic therapy to prevent stroke can vary according to the magnitude
of these risks. Clinicians can use the treatment recommendations of this study
to provide rational stroke prevention therapy for older patients with atrial
fibrillation.
(SEE ARTICLE)
Effectiveness of Thrombolytic Therapy for Acute Myocardial Infarction
in the Elderly: Cause for Concern in the Old-Old
Soumerai and colleagues report the results of an observational study
regarding the use of thrombolytic agents in a large community population of
patients with acute myocardial infarction. The findings suggest that thrombolytic
use is associated with reduced mortality among eligible patients younger than
80 years, but increased mortality among the very old, even among those without
relative or absolute contraindications to therapy. A substantial proportion
of thrombolytic recipients in the study (38%) had relative and absolute contraindications
to treatment, and this was strongly associated with an increased risk of mortality.
(SEE ARTICLE)
Statin Use, Bone Mineral Density, and Fracture Risk: Geelong Osteoporosis
Study
Statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors)
stimulate bone formation in vitro and in rodents. Recent data from separate
studies suggest that statins used in the treatment of hypercholesterolemia
decrease fracture risk and increase bone mineral density (BMD). Current statin
use and BMD were evaluated in 573 women (aged 50-95 years) with incident fracture
and in a random sample of 802 women (aged 50-94 years) without incident fracture,
drawn from the same community. There were 16 statin users in the fracture
group and 53 in the nonfracture group. Unadjusted odds ratio (OR) for fracture
associated with statin use was 0.40 (95% confidence interval [CI], 0.23-0.71).
Adjusting for BMD at the femoral neck, spine, and whole body increased the
OR to 0.45 (95% CI, 0.25-0.80), 0.42 (95% CI, 0.24-0.75), and 0.43 (95% CI,
0.24-0.78), respectively; adjusting for the potential confounders age, weight,
dietary calcium intake, alcohol consumption, smoking, activity levels, and
exposure to hormone replacement therapy, glucocorticoids, or calcium and/or
vitamin D supplements had no effect on the OR. Statin use was associated with
a 3% greater age- and weight-adjusted BMD at the femoral neck (P = .08), and BMD tended to be greater but did not achieve statistical
significance at the spine and whole body. Results suggest that increases in
BMD associated with statin use are small and may be insufficient to account
for the observed 60% reduction in fracture risk. Unless confounded by unrecognized
factors, statin use is associated with substantial protection against fracture,
but the mechanisms of action remain unclear.
(SEE ARTICLE)
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