It helps patients with moderate to severe heart failure -- those who experience symptoms at rest or with mild exertion. And there's strong evidence that it can prevent first-time heart failure in some high-risk patients.
The pacing device -- introduced in the U.S. six months ago -- helps the heart's main pumping chambers get back in step with one another. The treatment is called cardiac resynchronization therapy, or CRT. It calls for tiny electrodes to be threaded through veins into two chambers of the heart.
A report here at an annual meeting of heart specialists shows it cuts rates of hospitalization for heart failure. It seems to reduce the risk of death, too -- but only a larger trial will tell.
"CRT significantly reduces the risk of hospitalization and other measures of worsening heart failure," says lead study author William T. Abraham, MD. "From 500,000 to more than a million patients would be candidates for this treatment. I believe the cardiology community already has embraced the use of CRT."
The study looked at more than 500 patients who received the device. Half the patients had the device turned on, the others didn't. After six months, all patients were switched on. The results:
- CRT patients had worsening heart failure only half as often.
- When CRT patients did go back to the hospital, their stay was cut from 7.0 to 3.4 days.
- The risk of death or worsening heart failure dropped by 40% in the CRT group.
- CRT patients had a 57% lower chance of worsening heart failure requiring intravenous heart medication.
Medtronic Inc. makes the device, called InSync. Medtronic is a WebMD sponsor.
Abraham says that the success rate for implanting the InSync device is higher than 90% and should get much better as doctors become more familiar with the still-new technique.
Another conference presentation suggests that upgrading from a conventional pacemaker to the InSync device makes good sense for many patients.
Jean-Claude Daubert, MD, of University Hospital in Rennes, France, looked at patients who were candidates for getting pacemakers.
"This is an important group, because a fourth to a third of patients develop heart failure," Daubert says.
Treating these patients with CRT yielded encouraging long-term results.
"If larger, ongoing studies turn out OK, we can expect expansion of the number of patients who can use this therapy," Daubert says. "There will be an evolution towards using CRT for prevention in patients [who qualify for a pacemaker] and have evidence of heart dysfunction but do not yet have clinical heart failure."