Rochester, NY - Following previous studies of the cost-effectiveness of implantable cardioverter defibrillators (ICDs) in "MADIT-2-like" patients, a new analysis does the same thing using the real McCoy [1].

Focusing solely on their US patients with complete cost-related data, Dr Jack Zwanziger (University of Illinois, Chicago) and colleagues of the second Multicenter Automatic Defibrillator Implantation Trial (MADIT-2) determined an ICD-related cost of $235 000 per year of life saved (YOLS) over the study's 3.5-year follow-up horizon. But estimates fell to the range of $78 600 to $114 000, depending on calculation methods, when the data were extrapolated to 12 years.

Although the analysis wasn't designed to show it, the group writes, cost-effectiveness was consistently better among certain higher-risk subgroups.

"Significant issues are certainly at stake," observe the authors. Based on Medicare statistics, extending ICD therapy to all MADIT-2-like patients in the US would cost more than $5 billion per year, they write in a Journal of the American College of Cardiology report released online May 5, 2006 and scheduled for the journal's June 6 issue.

Their costliness makes it essential that they be targeted to populations for whom they confer substantial benefits.

"Implantable cardioverter-defibrillators have been shown to substantially reduce the number of sudden cardiac deaths, but their costliness makes it essential that they be targeted to populations for whom they confer substantial benefits," according to the group.

Dr Daniel B Mark (Duke University, Durham, NC), who led the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) cost-effectiveness study, said that the MADIT-2 results are largely consistent with those of that trial, despite some differences in the assumptions on which the analyses are based. "They're just different versions of the same model. They've made somewhat more conservative extrapolations than we have, and we can get to their results by making more conservative extrapolations," he told heartwire.

MADIT-2 entered 1232 post-MI patients with an LVEF <30% who were randomized in the US and Europe to receive an ICD or conventional medical therapy only. Over an average 20-month follow-up, those with devices showed a 31% reduction in risk of sudden cardiac death.

In the current analysis of US participants, ICD cost-effectiveness appeared to vary substantially by certain risk factors. It seemed better among patients aged 65 years or older, in NYHA functional class 2 or higher, or with a QRS duration >120 ms or blood-urea nitrogen >25 mg/dL.

The findings are not far removed from a prior analysis of MADIT-2-like patients from a 15-year experience at Duke University Medical Center, one that used similar calculation methods [2]. As described by Al-Khatib et al in a 2005 publication and reported then by heartwire, ICD cost-effectiveness was found to be about $79 900/YOLS over 12 years and $50 505/YOLS over a patient's lifetime.

If you can go more than seven or eight years with benefit, the likelihood is that the cost-effectiveness ratio will be below $100 000 per added life-year. If you can get a few more years of benefit beyond that, you may approach $50 000.

In the 2521-patient SCD-HeFT trial, primary-prevention ICDs in patients with stable NYHA class 2-3 HF and an LVEF <35% were associated with a 23% drop in five-year all-cause mortality compared with standard medical therapy only. Its cost analysis, which Mark presented and heartwire covered at the American Heart Association 2004 scientific sessions, found that ICD therapy cost $33 192 per YOLS. There was little variation in cost-effectiveness in analyses that broke patients out by age, LV function, QRS duration, and cardiomyopathy etiology.

The MADIT-2 analysis, Mark said, appears to focus primarily on the short time horizon covered by the study and less so on the 12-year figures. But the SCD-HeFT analysis centered on cost-effectiveness over the patient cohort's lifetime, he said. And although there was considerable overlap in the two trials' patient populations, SCD-HeFT used only single-chamber, single-lead ICDs that delivered therapy only as shocks. "Shock-only" devices are rare in the US but far less costly than the multifunction devices typically used.

The MADIT-2 and SCD-HeFT cost analyses weren't intended to arrive at "an answer" but to provide more of "an understanding of the nature of the problem," Mark said. "If you can go more than seven or eight years with benefit, the likelihood is that the cost-effectiveness ratio will be below $100 000 per added life-year. If you can get a few more years of benefit beyond that, you may approach $50 000 per added life-year."