Big News for Implantable Defibrillators: Indications Expanding

The principal investigator of this trial was Arthur J. Moss, MD, from the University of Rochester Medical Center, Rochester, New York (also the principal investigator of MADIT I). The study, which was sponsored by Guidant Corporation in St. Paul, Minnesota, demonstrated a 30% reduction in mortality in those who received an ICD compared with conventional medical therapy. This was the first completed prophylactic ICD trial which did not have an arrhythmia as an indication for implanting the device. This study randomized patients who had experienced a myocardial infarction at least 30 days prior and had a left ventricular ejection fraction of 30% or less to conventional medical therapy plus an ICD or conventional medical therapy alone. The positive results of this trial will expand device implantations to patients who meet the MADIT II studies entry criteria. The United States Food and Drug Administration will consider this information in order to modify the indications for implantable defibrillators. This will have profound implications. Preliminary market analysis has suggested that an additional $1.9 billion in growth in the ICD market will occur annually (with a doubling of ICD implants). This study is quite exciting for those in the field of electrophysiology; however, many questions still remain unanswered: What about those patients who have a left ventricular ejection fraction slightly above 30%? Are these patients at any less risk than those whose ejection fraction is 30%? What about patients with dilated cardiomyopathy? Certainly, the results of the Sudden Cardiac Death Heart Failure trial (SCDHeFT) will hopefully soon follow. This study has completed its enrollment phase and now is in the follow-up phase of the trial. This trial is looking at patients with mild to moderate congestive heart failure (New York Heart Association Class II or III with no arrhythmia, and an ejection fraction less than 36%.) Patients were randomized to placebo, amiodarone, or an ICD. What about the role for EP testing? As electrophysiologists, do we aggressively look for bundle branch re-entrant VT to ablate? Electrophysiologists need to define the conduction system prior to device implants. What about HCFA and reimbursement? The cost of devices ($20-30,000) can certainly tax the health care system. Less expensive devices might need to be produced as fail safe for each patient s status post-MI with severe LV dysfunction. Remember, if we can prevent sudden death, we will ensure a longer, more productive life for many high-risk patients.