The high initial cost of the ICD device and the implantation procedure leads to higher long- term costs, because there are few, if any, subsequent cost-savings from implanting an ICD. ICDs without resynchronization capability do not reduce hospital re- admissions and may increase late costs due to device monitoring, complications, and replacement. However, the cost of the device and the procedure may change significantly over time. The trial based assessments of the cost-effectiveness of the ICD are based on 3 to 6 years of follow-up, which is considerably shorter than the lifetime perspective that is standard in cost-effectiveness models. Because most of the incremental cost of the ICD is incurred imme- diately, while most of the potential effectiveness (life- years of survival added by the ICD) is accrued over many years, estimates of ICD cost-effectiveness based on lim- ited trial follow-up have a systematic bias toward show- ing lower value. Trial based economic studies that pro- jected long-term ICD outcomes have consistently found more favorable cost-effectiveness ratios than estimates restricted to the duration of trial follow-up.S16-4 S16-7 A CLINICAL STATEMENTS AND GUIDELINES lifetime simulation model applied to each major trial of primary prevention ICDs also reported consistently more favorable estimates of cost-effectiveness than the estimates based on limited trial follow-up.S16-11 Because the framework proposed for assessing value in ACC/ AHA clinical practice guidelines uses benchmarks based on lifetime estimates,S16-1 we have generally relied on the model-based estimates of ICD cost-effectiveness in applying value ratings to recommendations in this guideline. The initial cost of an ICD device is similar regardless of the clinical indication, so variations in ICD cost-ef- fectiveness are driven primarily by potential differences in clinical effectiveness in extending survival in differ- ent patient populations. 