Endometriosis, a prevalent disease, is associated with significant cardiac disease

Abstract Background Endometriosis, a chronic systemic gynecological disease affecting 10% of women in the reproductive age, shares pathophysiological characteristics with cardiovascular disease. However, data on the relationship between endometriosis and cardiac outcomes are scarce. Further research is needed to address this gap in knowledge as highlighted by recent calls from the European Heart Journal. Purpose To examine the incidence of the following outcomes both as a composite and individually: 1) ischemic events, 2) arrhythmias, and 3) heart failure among women with endometriosis compared with the background population. Methods Using Danish nationwide registries, all women with a diagnosis of endometriosis (1977-2021) were identified and matched with women from the background population in a 1:4 ratio based on year of birth. The incidence of 1) ischemic heart disease and ischemic stroke, 2) arrhythmias (including atrial flutter/fibrillation), and 3) heart failure were examined and compared between women with and without endometriosis. Results After exclusion of women with ischemic events/arrhythmias/heart failure prior to index, 59,194 women with endometriosis and 238,352 matched controls were included (median age 37.1 years [IQR 29.8-44.4 years]). The women were followed for a median of 17 years and a maximum of 45 years. Overall, women with endometriosis were more comorbid and used more medications than their matched controls. The 40-year cumulative incidences of the composite outcome were 36.2% (95%CI 35.4-37.1%) and 30.2% (95%CI 29.8-30.7%) among women with and without endometriosis, whereas it were 23.8% (95%CI 23.0%-24.5%) and 18.8% (95%CI 18.5%-19.1%) for ischemic events, 20.1% (95%CI 19.4%-20.9%) and 17.2% (95%CI 16.8%-17.5%) for arrhythmias, and 7.5% (95%CI 7.0-8.0%) and 6.6% (95%CI 6.3-6.8%) for heart failure, respectively (Figure 1). The most common arrhythmia was atrial fibrillation/flutter constituting more than half of the events in both groups. In both unadjusted and adjusted analyses, women with endometriosis compared with controls had a significantly higher associated risks of the composite outcome (unadjusted HR 1.30 [95%CI 1.27-1.34], adjusted HR 1.29 [95%CI 1.25-1.32]), ischemic events (unadjusted HR 1.32 [95%CI 1.28-1.37], adjusted HR 1.31 [95%CI 1.26-1.35]), arrhythmias (unadjusted HR 1.25 [95%CI 1.20-1.30], adjusted HR 1.24 [95%CI 1.19-1.29]), and heart failure (unadjusted HR 1.07 [95%CI 1.01-1.14]), adjusted analysis (HR 1.05