"We have been publishing for several years, because it became apparent that the potential importance of resting heart rate in determining prognosis is not so well understood," he said.
Perhaps the first study to indicate the possible importance of the resting heart rate was done during World War II, looking at the medical records of 25,000 army officers, Borer said. "Those with a resting heart rate above 100, about 300 of them, had a very poor long-term outcome," he noted.
In recent years, studies done in Norway have looked at possible beneficial effects of lowering the resting heart rate, using drugs such as beta blockers, Borer said. Studies of people with heart failure, the progressive loss of the heart's ability to pump blood, and of those who had suffered heart attacks, did show a benefit from slowing the heart rate, he added.
And a report on 25,000 cardiac patients done by Dr. Jean-Claude Tardif, of the Montreal Heart Institute, showed "a clear distinction in outcome based on resting heart rate," Borer added.
While there obviously are differences among individuals as to the best resting heart rate, "it is probably best if it is somewhat lower than 70" for an adult, he said.
Definitive evidence on the value of using a drug to lower the resting heart rate is expected from the two international trials now in progress, one including people with coronary artery disease, the other including people with heart failure, Borer said.
Results of those studies should be available by the late summer of 2008, he said.
Learn more about the resting heart rate from the U.S. National Library of Medicine.
SOURCES: Jeffrey S. Borer, professor, cardiovascu
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