Increased Heart Rate Boosts Heart Attack Risk in Women
According to the results of a new analysis from the Women's Health Initiative (WHI), increased heart rate is a definite risk factor for women that can increase risk of heart attack.
The findings, published February 3, 2009 in BMJ, looked at 2281 women with heart attack or death from heart attack over a period of 7.8 years. The researchers also looked at the incidence of stroke. After adjusting for factors such as exercise, cholesterol and blood pressure measurements, they found that increased heart rate alone boosted the women's risk of heart attack by 26 percent.
According to Dr Judith Hsia, "Multiple studies in men have previously shown that a high heart rate, after adjustment for other potential confounders such as blood pressure and cholesterol, is associated with an increased risk of heart attack and coronary death. But this is the first demonstration in women that having a high heart rate increases this risk."
Resting heart rate above 76 bpm predicted of heart attack among the women. The strongest association with increased heart rate and heart attack in the women was found after menopause, at age 50 to 64. The risk was the same regardless of ethnicity.
Dr. Hsia says the researchers are not certain why heart rate boosts heart attack risk in women. She explains, "Heart rate is thought to reflect a balance between the adrenaline side of the system and the vagal side, so it may be that the 'thermostat' is set on the high side for adrenaline in those women who have a higher heart rate.
The researchers say physical activity among the women had no impact on the analysis results. Diabetes and cigarette smoking were stronger predictors of heart attack risk in women, but the researchers say the findings "might be large enough to be clinically meaningful."
The study is important for women when making decisions about heart attack prevention. The combination of high cholesterol, high blood pressure, and increased heart rate can guide women and physicians in making choices about aggressive treatment to decrease women's risk of heart attack and death from heart disease.
The new research provides a non-invasive, low-tech means of measuring the risk of heart attack in women. Increased resting heart rate is easily measured during a routine exam at the doctor's office. The study shows a strong association between increased resting heart rate in women and increased risk of heart attack and death from heart attack, especially in younger postmenopausal women.