A team of scientists analyzed records of 129,135 postmenopausal women who had no history of heart problems. Their pulse rates were measured at the start of the study. The researchers found that during almost eight years of follow-up, women with the highest heart rates -- at or above 76 beats per minute -- were much more likely to suffer a heart attack than the women with the lowest resting pulse rates, 62 beats per minute or less.
This association held true regardless of factors such as physical activity levels and did not differ between races or women with or without diabetes, high blood pressure, or cholesterol abnormalities, according to the study authors, led by Judith Hsia, MD, a professor at George Washington University School of Medicine and senior director of clinical research for the pharmaceutical company AstraZeneca.
Even after adjusting for factors which might affect resting heart rate, including nervousness, depression, tobacco use, alcohol use, and body mass index, women with higher baseline heart rates were still at greater risk for heart attack during follow-up. The relationship between resting heart rate and coronary risk was stronger in women less than 65 years old than in women over 65.
The data for the study came from the Women's Health Initiative. Women with a history of heart attack, stroke, or similar serious problems were excluded. Resting heart rate was obtained by trained observers after the women sat "quietly" for five minutes.
Although more expensive and elaborate methods are available to assess risk, Hsia and colleagues "found that simple measurement of resting pulse independently predicts coronary events, but not stroke, in post-menopausal women."
The study appears in the Feb. 4 issue of BMJ.