In Reply: Dr Soliman agrees that risk-benefit ratios need to be established for ICDs for primary prevention in the Medicare population and extends this quandary to the entire population.
He outlines the challenges of defining a population at high enough risk of sudden cardiac death so that the benefit of an ICD will outweigh the risks. Current risk-prediction models are not precise, and in general, the risk of sudden cardiac death is much lower for primary prevention than for secondary prevention. Thus, about 17% to 25% of primary prevention ICD recipients receive any shock, and they are twice as likely to receive an inappropriate shock as an appropriate shock.1
The benefit of appropriate shock must be balanced against the risks of implantation and of inappropriate shock, the decrement in quality of life,2
and the anxiety engendered in healthy patients who learn that their implanted lead had been recalled, an increasingly common issue.3 Unfortunately, there are no reliable ways to improve precision in predicting which patients among the large population of primary prevention will experience a life-threatening arrhythmia. I agree that such tools are necessary for determining the appropriate use of ICDs.
Redberg RF. Predicting Benefit for Implantable Cardioverter-Defibrillator Use—Reply. JAMA. 2008;299(3):286-287. doi:10.1001/jama.299.3.287-a