Abstract
IntroductionHeart failure (HF) and breast cancer are highly prevalent and are two of the leading causes of death in postmenopausal women. Few studies to date have examined the impact of HF and breast cancer on outcomes in postmenopausal women.ObjectivesWe seek to examine the impact of incident breast cancer and incident HF on survival in patients with background prevalent HF and breast cancer, respectively.MethodsWe 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, breast cancer, and survival outcomes were centrally adjudicated through 2017. Cox proportional hazards model adjusting for age was performed.ResultsAmong a cohort of 44,174 (mean age63±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-up14 years and 15 years, respectively). Prognosis of incident HF was worse than that of incident invasive breast cancer (median survival5.3 and 18.5 years, respectively). In patients with incident invasive breast cancer, prevalent HF was associated with an increased risk of all-cause mortality [adjusted hazard ratio (HR) 2.32; 95% CI 1.34-4.02]. In patients with incident HF, prevalent breast cancer was associated with an increased risk of all-cause mortality (adjusted HR 1.66; 95% CI 1.03-2.68).ConclusionsAmong a large cohort of postmenopausal women, the presence of incident invasive breast cancer or incident HF in those with prevalent HF or prevalent breast cancer, respectively, was associated with an increased risk of all-cause mortality. Importantly, mortality after incident HF was much higher compared with mortality after incident invasive breast cancer.