Abstract
IntroductionHeart failure (HF) and breast cancer are two of the leading causes of death in postmenopausal women. The temporal association between HF and breast cancer in a cohort of postmenopausal women has not been described.ObjectivesWe seek to examine the temporal association between HF and breast cancer incidencesMethodsWe studied postmenopausal women within the 40 participating centers of the Women’s Health Initiative (WHI) who were enrolled between 1993 and 1998. All incident hospitalized HF and breast cancer outcomes were centrally adjudicated through 2017. The associations between prevalent HF and incident breast cancer and prevalent breast cancer and incident HF were determined using the Kaplan Meier estimate and Cox proportional hazards model.ResultsAmong a cohort of 44,174 (mean age, 63±7 years) within the 161,808 women in the WHI, 2,688 participants developed incident breast cancer (of which 2,188 were invasive) and 2,417 developed incident HF (median follow-up 14 years and 15 years, respectively). When compared to a breast cancer- and HF-free cohort, there was no association between prevalent HF and incident breast cancer (p=0.98) or incident invasive breast cancer (p=0.27). Similarly, there was no association between prevalent breast cancer and incident HF (p=0.46). Shared risk factors for breast cancer and HF include age, obesity, alcohol use, physical inactivity, and elevated resting heart rate.ConclusionsAmong a large cohort of post-menopausal women, prevalent HF was not associated with a higher incidence of breast cancer and similarly, prevalent breast cancer was not associated with a higher incidence of incident HF. The lack of association suggests a distinct pathophysiology that defines each condition.