This article is more than 5 years old. Information may no longer be current.
Chronotropic incompetence increased death risk in women
Click Here to Manage Email Alerts
Chronotropic incompetence was linked with a heightened mortality risk in asymptomatic women, according to study data.
“The traditional estimate of the maximum heart rate for age with exercise, based on the male standard, appears to be an overestimate in women,” the researchers wrote in their study.
The study included asymptomatic women (n=5,437) from the Chicago area who underwent a symptom-limited maximal stress test in 1992 as part of the St. James Women Take Heart Project. Researchers determined heart rate reserve, chronotropic index and age-predicted peak heart rate. They calculated death up until Dec. 31, 2008, through a Social Security Death Index search.
The mean patient age at baseline was 52 ± 11 years, with 549 deaths during a period of 15.9 ± 2.2 years. Mean peak heart rate was inversely related with age (206 minus 88% of age). Once researchers adjusted for exercise capacity and traditional CV risk factors, every one-beat-per-minute increase in peak heart rate corresponded with a decrease in death risk by 3%, whereas that same increase in heart rate reserve lowered the death risk by 2%. Additionally, researchers found that the predominantly male-based estimate for maximum heart rate for age with exercise is an overestimate for women.
“We have demonstrated that sex-specific chronotropic incompetence is independently associated with an increased risk of all-cause mortality in women,” the researchers wrote. They also said it is important to incorporate sex-specific parameters of physiological heart rates response to exercise into clinical practice. – by Brian Ellis
Gulati M. Circulation. 2010;doi:10.1161/CIRCULATIONAHA.110.939249.
This study provides us with some important new information derived from a population of women, which allows for a better estimate of maximum heart rate in women. Perhaps even more importantly, with this better estimate, we can now more closely assess long-term risk in women. Now that we understand the equation is different for men and women, hopefully the equation put forth by Gulati et al can be replicated and validated in additional cohorts of women, and this equation will be incorporated clinically to provide a more accurate prediction of long-term prognosis to women.
– Rhonda Cooper-DeHoff, PharmD, MS
Cardiology Today Editorial Board member