Sex Differences in Hospital Mortality in Adults With Congenital Heart Disease: The Impact of Reproductive Health

Abstract

The study objectives were to analyze sex differences in hospital mortality of adult patients with congenital heart disease (CHD) and to determine the impact of health services associated with pregnancy on outcomes in women. The determinants of sex differences in the demographic distribution of CHD are poorly understood. The Quebec CHD database and the Dutch CONCOR (CONgenital CORvitia) registry were used to identify patients with CHD aged 18 to 65 years who were hospitalized between 1996 and 2005. Regression analyses were used to compare 30-day in-hospital mortality in men versus women and in women aged 18 to 45 years with versus without a pregnancy history, after adjustment for age, CHD severity, comorbidities, and admission diagnosis. Of 39,776 patients followed for 259,741 patient years, 19,099 patients (48%) had 54,195 admissions (62% among women). In those aged 18 to 45 years, 30-day in-hospital mortality was higher in men compared with women with nonpregnancy admissions (adjusted rate ratio: 1.36; 95% confidence interval: 1.02 to 1.81). The adjusted rate ratio for 30-day in-hospital mortality in women with a pregnancy history compared with those without was 0.49 (95% confidence interval: 0.24 to 0.99). A history of pregnancy was not associated with an overall increase in medical encounters. We demonstrated a protective effect of sex on in-hospital mortality in women with CHD of reproductive age that did not correlate with increased medical surveillance. Future studies need to explore other mechanisms to account for our observations. Understanding the determinants of the sex distribution of adults with CHD is important for our ability to predict demographic changes in the population with CHD.