Defibrillators may have little benefit for older, sicker patients

Defibrillators are commonly recommended to patients with heart failure to prevent sudden cardiac death, but beyond having heart failure, there is a lack of criteria to identify the appropriate patients for this therapy.

Researchers at Brigham and Women’s Hospital (BWH) found that older people with comorbidities and those with multiple hospital admissions related to heart failure are unlikely to receive a meaningful survival benefit from implanted defibrillators. These findings appear in the March 17 issue of the Canadian Medical Association Journal.

Even if all out-of-hospital cardiac deaths were prevented by implanted defibrillators, the researchers found that survival was significantly lower in patients who were repeatedly hospitalized for heart failure. Similarly, survival was poor for older patients with comorbidities, such as cancer, dementia, and kidney disease. However, patients under 65 years of age and older patients without kidney disease, cancer, or dementia would be most likely to benefit from defibrillators to prevent sudden death. 

“Previous trials show significant benefits of defibrillators in patients with heart failure, but the study populations typically exclude elderly patients and those with comorbidities,” said Soko Setoguchi, of the department of medicine at Brigham and Women’s Hospital (BWH).

However, information from the U.S. National Cardiovascular Data Registry from 2006 through 2007 indicates that defibrillators are frequently implanted in patients with comorbidities, and 61 percent of implanted defibrillators go to people aged 65 or older.

The study looked at more than 14,000 patients admitted to a hospital for heart failure from an administrative database. The average age of the group was 77 years, and patients had a high prevalence of comorbidities such as other cardiovascular disease, diabetes, chronic pulmonary disease, and kidney disease. Researchers tracked the patients, recording the number of hospital admissions due to heart failure, the development of comorbidities, and the cause of death, when appropriate. 

“Patients at extremely high risk of death, including patients with prior heart failure hospitalizations and chronic disease, have such a high risk of all-cause death that even if the potentially treatable sudden cardiac deaths were prevented, the overall risk of death would remain prohibitively high,” notes Setoguchi.