Elevations in heart rate are generally higher in women than in men, with little risk being associated with this difference. However, older women are more likely to have a disability or chronic disease that affects their daily function. Among this specific population, heart rate may have a stronger association with poor outcomes and may be a simple indicator of mortality, regardless of the presence of heart disease. Chang and associates evaluated the association of elevated heart rate with three-year mortality in women living with moderate to severe disability.
Women enrolled in the Women’s Health and Aging Study I conducted by the Johns Hopkins Medical Institutions made up the study population. The study population included 1,002 disabled women who were at least 65 years of age living in Maryland, who reported difficulties in at least two domains of physical disability, and who scored 18 or better on the Mini-Mental State Examination. Functional and physical status were evaluated in all participants. Heart rate was determined by electrocardiography after a five- to seven-minute rest period.
Adequate three-year mortality and heart rate data were available for 942 women. The mean heart rate in the total population, including those with and those without heart disease, was 71 to 72 beats per minute. A heart rate of 90 beats per minute or greater was associated with younger age, lower summary performance score, and lower forced expiratory volume in one second.
Over the three years of follow-up, the survival rate was lower among women with heart rates of 90 beats per minute or greater, even when participants receiving beta blockers were excluded; however, this difference did not quite reach statistical significance. Among women with no evidence of heart disease, a heart rate of 90 beats per minute or greater proffered a twofold increased risk of mortality over the three-year period compared with the group having heart rates of 60 to 89 beats per minute, even after adjusting for activity and cardiovascular risk factors.
The authors conclude that an elevated heart rate in a disabled older woman is associated with increased mortality risk. The latter may be caused by increased mechanical stress on the arterial wall and heart or by autonomic nervous system influences on the heart resulting in atherogenesis. Women with elevated heart rates might benefit from more intensive clinical evaluation.