Valvular heart diseases in immigrants and Swedish-born individuals: a national cohort study

Objectives. The aim of this study was to analyse the risk of valvular heart diseases among foreign-born individuals in Sweden. Design. This was a nationwide study of individuals aged 18 years of age and older (N = 6,118,649; 2,970,055 men and 3,148,594 women). Valvular heart diseases were defined as at least one registered diagnosis in the National Patient Register between 1 January 1998 and 31 December 2012. Cox regression analysis was used to estimate hazard ratios (HR) with 99% confidence intervals (CI) of incident valvular heart diseases in foreign-born individuals compared to Swedish natives. The Cox regression models were adjusted for age, co-morbidities, and sociodemographic factors. Sub-categories were chronic rheumatic valvular heart diseases and non-rheumatic valvular heart diseases. Results. There were 64,979 male cases and 59,075 female cases. Fully adjusted HRs (99% CI) were among immigrant men 0.86 (0.82–0.89) and immigrant women 0.96 (0.92–1.00). For chronic rheumatic valvular disease among immigrant men and women, the HRs were 1.62 (1.37–1.92) and 1.75 (1.52–2.00), respectively, and, for non-rheumatic valvular disease among immigrant men 0.83 (0.80–0.87) and immigrant women 0.92 (0.88–0.96). Increased risks for chronic rheumatic valvular disease were found among men from Southern, Eastern and Central Europe, Africa and Asia and among women from Western, Eastern and Central Europe and Africa, Latin America and Asia. Conclusions. We observed lower risks in general of valvular heart disease, but higher risks of chronic rheumatic valvular heart disease in immigrants, which is important in the clinical situation.