Implantable cardioverter-defibrillator (ICD) devices are associated with lower rates of risk-adjusted mortality at 2 years in older patients, but a study led by Duke researchers showed that fewer than 10% of eligible patients receive them within 1 year following myocardial infarction (MI). And, each year, more than 300,000 Americans die from sudden cardiac arrest.
The study, published in the Journal of the American Medical Association, looked at 10,318 study patients with MI. Data were collected from 441 hospitals across the country between the years 2007 and 2010.
On average, the study patients were 78 years of age; 44% were older than 80 years. They were also Medicare beneficiaries with an ejection fraction of 35% or lower following MI.
According to the study authors, advanced age, transitions in care between hospitals and outpatient clinics, and a mandatory waiting period to receive an ICD following MI contributed to low usage rates. In the study, patients with ICDs had a one-third lower risk of death after 2 years than those without an ICD.
“Not every older patient wants an ICD, but current data suggest that we are grossly underutilizing this therapy,” says Tracy Wang, MD, associate professor of cardiology at Duke Medicine and senior author of the study.
Wang explains that quality of life and trade-offs between the risks and benefits of an ICD should be considered. “The decision about defibrillators has to be individualized. For older, debilitated patients, providing a defibrillator could simply extend a low quality of life,” she comments.
Sean Pokorney, MD, a cardiology fellow at Duke Medicine and lead author of the study, explains that age alone should not prevent eligible patients from receiving an ICD. Although it cannot be expected to be used in 100% of cases, he advises patients to make an informed decision with their health care provider.
“We should try to understand how to refine patient selection toward those who are most likely to benefit from the device,” he says, “and close any system-level gaps that present a barrier to optimal defibrillator use.”
For example, gaps can occur after patients are discharged from the hospital, Pokorney points out, because they may not seek outpatient care. Patients who see a cardiologist and attend follow-up appointments are more likely to receive an ICD than their counterparts.
Although the optimal timing for implanting a defibrillator is not yet known, current guidelines recommend that patients wait at least 40 days following MI, explains Pokorney. “If, despite good medical therapy, the patient’s heart is still having trouble pumping blood after 40 days, the patient is eligible. “But,” he underscores, "a lot can happen in that 40 days.”