Cardiac resynchronization therapy devices during hospital stays linked to better outcomes

Mar 14 2006

Placement of devices that synchronize the pumping chambers of the heart in patients while they're hospitalized for a congestive heart failure episode appears to lower patients' risk of death or rehospitalization during at least the next two to three months, new research suggests.

The observational study researchers presented Monday (3/13) at the annual meeting of the American College of Cardiology suggests that early placement of such cardiac resynchronization therapy (CRT) devices could prolong the lives of patients with congestive heart failure, said Dr. William Abraham, director of cardiovascular medicine at The Ohio State University Medical Center and the lead author of the presentation.

"The improvement in outcome with early device placement is striking," Abraham said. "Unfortunately, many practitioners wait to consider use of these devices until after patients have been out of the hospital for some time, and most patients are unaware that they are available."

Abraham and colleagues analyzed data on 5,791 patients who were follow-up participants in Optimize-HF, a national initiative designed to standardize and improve treatment of patients hospitalized with congestive heart failure (CHF) that initially tracked outcomes of almost 49,000 patients. Abraham was a member of the Optimize-HF national steering committee.

Of those evaluated in the follow-up group, 132 patients received the CRT devices while they were hospitalized for such symptoms associated with heart failure as shortness of breath and excessive fluid retention. A comparison of the outcomes of those patients and the remaining 5,659 patients in the follow-up group showed significantly fewer rehospitalizations among the group with the implanted devices as well as a trend toward fewer deaths, said Abraham, also associate director of the Davis Heart and Lung Research Institute at Ohio State.

Specifically, the death rate in the first 60 to 90 days after discharge of patients with CRT devices was 6.2 percent, vs. 8.3 percent of patients who did not receive the devices. Only 18.2 percent of CRT patients were rehospitalized after discharge, compared with 29.9 percent of patients who did not receive the devices. The percentage of patients who died during the initial hospitalization also appeared to be affected by placement of the devices: Only 1.3 percent of patients who received the devices died during the same hospitalization, compared to 3.8 percent of patient deaths among those who did not receive the devices.

The placement of the devices did, however, extend the average length of stay during the hospitalization in which the CRTs were implanted: The average was 6.4 days for patients who received the devices, compared to 5.6 days for other patients.

Congestive heart failure affects an estimated 5 million Americans, and is characterized by a reduced ejection fraction - a measurement of how well the heart is squeezing - and often by seepage of fluid into the lungs, feet, legs or abdominal cavity.

Hearts with unsynchronized chambers don't pump as well; the extra work enlarges the heart, and the resulting reduced oxygenation of the blood weakens the heart. Heart failure is the most common cause of hospitalization for older people.

Cardiac resynchronization therapy, also called biventricular pacing, coordinates the pumping action of both sides of the heart. Some CRT devices are combined with implantable cardioverter defibrillators, which can deliver a shock to stop cardiac arrest. The CRT devices are about the size of a pocket watch, placed under the skin in the chest, and are attached by leads to deliver electrical pulses to both sides of the heart.

Clinical trials to date, some led by Abraham, involving about 4,000 patients have demonstrated the devices offer consistent improvement in quality of life, functional status and exercise capacity in patients with CHF. The devices also appear to reverse some of the physical damage to the heart associated with the disease, and prolong survival.

The device therapy is currently recommended for patients with CHF whose left ventricular ejection fraction is below 35 percent and who exhibit classic symptoms and experience dyssynchrony among the pumping chambers despite optimal medical therapy. Clinical trials have evaluated device placement in outpatients on stable medical therapies rather than in hospitalized patients, Abraham said. What's new is the finding that placement of these devices during a heart failure hospitalization may improve outcomes, as well, suggesting that physicians should not wait until weeks or months later to recommend resynchronization therapy.

"It's already clear that these devices improve the quality of life for patients with congestive heart failure," he said. "If these results are supported by additional clinical research, it appears that earlier placement of these devices could further lower the risk of death associated with this disease."

http://medicalcenter.osu.edu/