People with heart failure can get delayed benefits from biventricular pacing

23rd November 2015

Many heart failure patients who initially get no benefit from having a biventricular pacemaker can still go on to do better later, says a new study.

In some people with heart failure, their hearts beat in an uncoordinated way, leaving them with many symptoms. Biventricular pacing (also called cardiac resynchronisation therapy or CRT) can help the different chambers of the heartbeat in unison and ease symptoms. But some people see no improvement in the early months after having the heart device fitted.

But now a new study, led by Dr Kevin Burns from the United Heart and Vascual Clinic in St Paul, Minnesota, America, showed that many patients who do not get early benefit from the device can do so later on. And survival and hospital admission rates among the late responders were similar to those with earlier improvements.

The study looked at 300 people given a biventricular pacemaker three years previously. A total of 120 were considered non-responders a year after having the device fitted. But 52 (43 per cent) had a delayed positive response, said the researchers in a report in the Journal of the American College of Cardiology.

The researchers said that up to a third of people who had the device saw now improvement after a year, but more than three out of four got a response after three years survival.

Dr Burns said: "The therapy appears to help more people than we originally thought. While many patients get a lot better immediately after CRT, a significant number appear to have delayed remodeling. This is important because over time even small improvements may have a big impact."

The study included 790 patients with heart failure who received a biventricular pacemaker at one heart centre from 2003 to 2011.

"We demonstrated in this study that nearly half of patients who are not echocardiographic responders after 6-12 months of CRT become responders long term," the researchers wrote.

They noted that while research is needed to better understand the reasons for delayed CRT response, the findings do have immediate clinical significance for patients considered CRT nonresponders.