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Longer or additional hospitalization (possibly for right ventricular pacing) on driving. Driving is typically not restricted among patients who receive defibrillators for primary prevention, because such patients have no history of an arrhythmia that might cause loss of control of a vehicle.
Factors affecting use o high-technology devices, the availability of trained electrophysiologists, and market penetration by manufacturers of cardioverter–defibrillators.
Estimates of the costs of implantable-defibrillator therapy depend strongly on the design used in the analysis. Implantable-defibrillator therapy has both a large up-front cost and considerable additional costs throughout the life of the device. If the estimates of costs and benefits used in a clinical trial are truncated at the close of the study, the result will overestimate the cost per year of life saved. Long-term data from the meta-analysis of the results of the AVID, CASH, and CIDS trials suggest that the survival benefits of defibrillator therapy for secondary prevention, in comparison with those of drug therapy, decrease over time and are negligible after about six years. Long-term economic data from trials on the primary prevention of sudden death are not yet available.
Although complex models for the economic assessment of defibrillator therapy have been described, the results have varied, owing to the wide range of assumptions made regarding the risk of death from arrhythmias in the patient population and the relative effectiveness of the therapies examined.
Summary
Implantable cardioverter–defibrillator therapy has been established as an effective method of preventing sudden death from cardiac causes. Few other interventions have been shown as consistently to have equivalent absolute and relative effects on survival among high-risk patients. New models of cardioverter–defibrillators may improve the functional status and quality of life of selected patients who are likely to benefit from biventricular pacing. The implantable defibrillator, however, is invasive and expensive and may expose patients to complications. Optimal use of implantable defibrillators in populations and in individual patients will depend on careful decision making by managers of health care systems, clinicians, and patients.
R e f e r e n c e s
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