CHICAGO (AP) _ Special pacemakers designed to correct a defect that affects close to 2 million heart failure patients in the United States can also prolong their lives, an analysis found.
While such pacemakers have been shown to improve quality of life and exercise capacity, their effects on survival had been unclear.
``I was surprised by the magnitude'' of the effects, said lead author Dr. David Bradley, a Johns Hopkins Hospital cardiologist.
Industry-funded studies have shown that the special devices improve the heart's pumping action in a process called cardiac resynchronization. Some studies had hinted that they might also extend lives but lacked the statistical power to make that link.
By pooling the results of four recent studies involving 1,634 patients, the researchers found that the devices reduced the death rate from heart failure by 51 percent among heart failure patients. Of these, 1.7 percent died within three to six months of getting the special pacemakers, compared with 3.5 percent of patients who got similar pacemakers but had the special feature inactivated.
The activated devices also were linked to a 29 percent reduction in hospitalization for complications related to heart failure.
The results appear in Wednesday's Journal of the American Medical Association.
Patients were mostly men in their 60s with moderate to severe heart failure. All also received heart failure medication such as beta blockers and ACE inhibitors.
The American Heart Association's Dr. Clyde Yancy called the results ``phenomenal'' and said they could lead to a substantial change in practice. Currently, only about 2 percent of eligible patients get the special devices, Yancy said.
The devices are intended for about one-third of the 5 million Americans with heart failure who also have pumping problems caused by an electrical ``short-circuit'' in the heart, said Dr. William Abraham, chief of cardiology at Ohio State University and an author of one of the studies analyzed. The abnormality prevents the heart's pumping chambers from squeezing at the same time.
While regular pacemakers speed up hearts that beat too slowly, the special devices use an electrical charge to synchronize the pumping action to make the heart beat more effectively.
Cardiac synchronization devices cost roughly $20,000 to $50,000, plus doctors' and hospital fees, Bradley said. Whether those costs are offset by the reduced hospitalization found in the study is unclear, he said.