Cardiac resynchronization may help some (but not all) heart failure patients live longer.

The news is reported by John Cleland, MD, and colleagues in The New England Journal of Medicine. They saw fewer deaths and bigger improvements in symptoms and quality of life in certain heart failure patients who got cardiac resynchronization plus standard medication, compared with those who just got the medications.

"The implantation of a cardiac resynchronization device should routinely be considered in such patients," writes Cleland, who works in the cardiology department of England's Castle Hill Hospital.

Who Got Tested

Because the findings focus on a specific type of heart failure, they don't necessarily apply to other heart failure cases.

Up to a third of heart failure patients have abnormal timing in the pumping action between the lower chambers of the heart. That makes it harder for the heart to pump blood effectively, which can worsen heart failure symptoms.

The researchers demonstrated that resynchronizing the lower chambers' pumping action can improve survival in patients with severe heart failure.

There were 813 participants. All had severe heart failure; their average age was about 66.

All patients got routine medical care for their condition. Half of the group also had a cardiac resynchronization device implanted in their heart. The device stimulated the heart's lower chambers to stay in synch.

Fewer Deaths With Cardiac Resynchronization

The patients were followed for 2.5 years, on average. During that time, there were 82 deaths in the cardiac resynchronization group (20 percent) and 120 in the group that didn't get cardiac resynchronization (30 percent).

That included deaths of any cause, but heart trouble was the most common cause of death (83 percent for all of the patients who died). Death due to worsening of heart failure accounted for 40 percent of deaths in the cardiac resynchronization group and 47 percent of the comparison group.

Sudden death was seen in 35 percent of those who got cardiac resynchronization and 32 percent of those who didn't.

Unplanned Hospitalizations Down, Quality of Life Up

The cardiac resynchronization group also had 162 fewer unplanned hospitalizations for major heart disease complications.

Heart function also improved more with cardiac resynchronization; so did quality of life 90 days after the procedure, the study shows.

The researchers say their findings on heart function, symptoms, quality of life, and blood pressure are similar to those reported in similar trials.

Side Effects

One device-related death was reported in each group. The most common device- or procedure-related side effect in the cardiac resynchronization group was displacement of the device's electrical lead (24 patients).

The study was funded by Medtronic, the device's maker. Medtronic did not have access to the study's database and wasn't involved in analyzing the results or writing the article, say researchers.

Several researchers had received speaker's fees or consulted for Medtronic and/or other health care companies, notes the journal's April 14 edition.

By Miranda Hitti, reviewed by Brunilda Nazario, MD

SOURCES: Cleland, J. The New England Journal of Medicine, April 14, 2005; vol 352: pp 1539-1549. WebMD Medical Reference provided in collaboration with The Cleveland Clinic: "Heart Disease: Biventricular Pacing to Treat Heart Failure (Cardiac Resynchronization Therapy)."