Summary

Previously resting heart rate has been shown to be linked to increased heart attack risk in women. Now researchers for the long-running Women's Health Initiative find a similar relationship for women. Measuring heart rate might therefore be a low tech and simple way of pinpointing women at higher risk of heart attack.

Introduction

The resting heart rate, which has a value of between 60 and 80 beats per minute, is an indicator of the tone of the autonomic nervous system. As such, it has been found to predict coronary events in men - with high rates indicating higher risk. But studies in women have not shown this association, save for one report from the National Health And Nutrition Examination Survey which did show a link between heart rate and cardiovascular death among African-American women. The relationship between heart rate and stroke in women is also unclear.

What was done

Researchers at George Washington University and elsewhere carried out this study as part of the Women's Health Initiative which involves 161,808 postmenopausal women. They recorded cardiovascular events (heart attack and stroke) during eight years of follow up and searched for any relationship between these events and resting heart rate.

What was found

There were 2281 heart attacks and 1877 women with stroke during the follow up period. Women with a higher resting heart rate - more than 76 beats per minute - were more likely to have a heart attack than those with a lower rate, defined as less than 62 beats per minute. No such link was found with stroke.

What this study means

Resting heart rate has more clinical significance than previously believed. It could be a simple and low cost way of assessing a woman's heart attack risk, in conjunction with other assessments.

Source

Hsia J Larson JC et al Resting heart rate as a low tech predictor of coronary events in women: prospective cohort study British Medical Journal Online First February 2009 doi:10.1136/bmj.b219