Abstract
BACKGROUND: Recent evidence has shown that reproductive factors are associated with an increased risk of heart failure with preserved ejection fraction in women. However, the pathogenic pathways underlying this relationship are unclear. Subclinical myocardial fibrosis has been found to be a common pathway in a large proportion of patients with heart failure with preserved ejection fraction. OBJECTIVES: This study examined the relationship between vital reproductive factors (parity, pregnancy, age at menopause, and use of hormone replacement therapy [HRT]) with interstitial myocardial fibrosis (IMF) and myocardial scar measured by cardiac magnetic resonance imaging (CMR) T1 mapping and late gadolinium enhancement, respectively. METHODS: There were 596 female participants (mean age 67 ± 8 years) enrolled in MESA (Multi-Ethnic Study of Atherosclerosis) who had complete parity data and underwent CMR. Parity was categorized as 0 live births, 1 to 2, 3 to 4, and ≥5 live births. Multivariable regression models were constructed to assess the associations of parity status, history of null gravidity, age at menopause and HRT with CMR obtained measures of IMF (extracellular volume [ECV], native-T1 time) and myocardial scar. RESULTS: Women with a history of nulliparity had greater ECV% (β = 0.95 ± 0.28, P = 0.001) and native-T1 ms (β = 10.6 ± 4.9, P = 0.03) than those who had 1 to 2 live births. These associations were independent of age, traditional cardiovascular risk factors, and interim cardiovascular events. Similar associations were found for women with a history of null gravidity compared to those with a history of pregnancy (ECV% [β = 0.7 ± 0.3, P = 0.02] and native-T1 ms [β = 10.6 ± 5.2, P = 0.04]). There was no association between age at menopause and HRT with markers of IMF. There were no associations between parity status, null gravidity, and age of menopause with the presence of myocardial scar; however, those who used HRT were independently associated with a lesser risk of myocardial scar (OR: 0.20; 95% CI: 0.05-0.82). CONCLUSIONS: In a multiethnic cohort, women with a history of nulliparity or null gravidity had greater IMF defined by CMR, while those who used HRT were less likely to have myocardial scar.