BACKGROUND: The definition of a normal heart rate (HR) response to exercise stress testing in women is poorly understood, given that most studies describing a normative response were predominately based on male data. Measures of an attenuated HR response (chronotropic incompetence) and age-predicted HR have not been validated in asymptomatic women. We investigated the association between HR response to exercise testing and age with prognosis in 5437 asymptomatic women. METHODS AND RESULTS: Participants underwent a symptom-limited maximal stress test in 1992. HR reserve (change in HR from rest to peak), chronotropic index, and age-predicted peak HR were calculated. Deaths were identified to December 31, 2008. Mean age at baseline was 52+/-11 years, with 549 deaths (10%) over 15.9+/-2.2 years. Mean peak HR was inversely associated with age; mean peak HR=206-0.88(age). After adjusting for exercise capacity and traditional cardiac risk factors, risk of death was reduced by 3% for every 1-beat-per-minute increase in peak HR, and by 2% for every 1-beat-per-minute increase in HR reserve (P<0.001). Inability to achieve 85% age-predicted HR was not an independent predictor of mortality, but being >/=1 SD below the mean predicted HR or a chronotropic index <0.80 based on the prediction model established by this cohort were independent predictors of mortality (P<0.001 and P=0.023, respectively). CONCLUSIONS: Chronotropic incompetence is associated with an increased risk of death in asymptomatic women; however, the traditional male-based calculation overestimates the maximum HR for age in women. Sex-specific parameters of physiological HR response to exercise should be incorporated into clinical practice.
BACKGROUND: The definition of a normal heart rate (HR) response to exercise stress testing in women is poorly understood, given that most studies describing a normative response were predominately based on male data. Measures of an attenuated HR response (chronotropic incompetence) and age-predicted HR have not been validated in asymptomatic women. We investigated the association between HR response to exercise testing and age with prognosis in 5437 asymptomatic women. METHODS AND RESULTS:Participants underwent a symptom-limited maximal stress test in 1992. HR reserve (change in HR from rest to peak), chronotropic index, and age-predicted peak HR were calculated. Deaths were identified to December 31, 2008. Mean age at baseline was 52+/-11 years, with 549 deaths (10%) over 15.9+/-2.2 years. Mean peak HR was inversely associated with age; mean peak HR=206-0.88(age). After adjusting for exercise capacity and traditional cardiac risk factors, risk of death was reduced by 3% for every 1-beat-per-minute increase in peak HR, and by 2% for every 1-beat-per-minute increase in HR reserve (P<0.001). Inability to achieve 85% age-predicted HR was not an independent predictor of mortality, but being >/=1 SD below the mean predicted HR or a chronotropic index <0.80 based on the prediction model established by this cohort were independent predictors of mortality (P<0.001 and P=0.023, respectively). CONCLUSIONS: Chronotropic incompetence is associated with an increased risk of death in asymptomatic women; however, the traditional male-based calculation overestimates the maximum HR for age in women. Sex-specific parameters of physiological HR response to exercise should be incorporated into clinical practice.
Authors: Mouaz H Al-Mallah; Stephen P Juraschek; Seamus Whelton; Zeina A Dardari; Jonathan K Ehrman; Erin D Michos; Roger S Blumenthal; Khurram Nasir; Waqas T Qureshi; Clinton A Brawner; Steven J Keteyian; Michael J Blaha Journal: Mayo Clin Proc Date: 2016-05-06 Impact factor: 7.616
Authors: Tom Cole-Hunter; Scott Weichenthal; Nadine Kubesch; Maria Foraster; Glòria Carrasco-Turigas; Laura Bouso; David Martínez; Dane Westerdahl; Audrey de Nazelle; Mark Nieuwenhuijsen Journal: J Expo Sci Environ Epidemiol Date: 2015-10-21 Impact factor: 5.563
Authors: Leslee J Shaw; Joe X Xie; Lawrence M Phillips; Abhinav Goyal; Harmony R Reynolds; Daniel S Berman; Michael H Picard; Balram Bhargava; Gerard Devlin; Bernard R Chaitman Journal: Heart Asia Date: 2016-06-01