The survival benefit of an implantable defibrillator for heart failure lasts at least 10 years

closeup image of a pacemaker

People with heart failure who received an implantable cardioverter-defibrillator (ICD) are more likely to be alive more than a decade later compared with those who didn’t, according to an NHLBI-funded study published in the Journal of the American College of Cardiology.

A previous study called the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) found the survival benefit of an ICD persisted for up to 5 years. This new analysis looked at the 1,855 people alive at the end of the SCD-HeFT trial 11 years later. Those who had received an ICD had a 13% decreased risk of death than those who received a placebo medication.

The researchers said the analysis shows that people who get the most benefit from an ICD are those with mild heart failure symptoms, such as shortness of breath and angina or chest pain, and those with ischemic cardiomyopathy or a weakened heart muscle due to blockages in blood vessels.

However, there was no survival advantage for people with nonischemic cardiomyopathy (NICM), a weakened heart muscle that isn’t caused by blocked blood vessels. People with NICM had a survival advantage at 5 years, but by 11 years, they were no better off than those who didn’t get an ICD. Researchers aren’t sure why the survival benefit in people with NICM dropped off by the 11-year mark.