Cardiomyopathy among first- and second-generation immigrants in Sweden: a nationwide total population study

Purpose: We aimed to analyze the risk of cardiomyopathies (CMPs) among first-generation and second-generation immigrants. Methods: All individuals aged 18 years of age and older, n = 6,123,661 in the first-generation study, and n = 4,587,764 in the second-generation study were analyzed. CMP was defined as at least one registered diagnosis in the National Patient Register between January 1, 1998 and December 31, 2018. Cox regression analysis was used to estimate the relative risk (hazard ratios (HR) with 99% confidence intervals (CI)) of incident CMP with adjustments made for age, cancer, other comorbidities, and sociodemographic factors. Results: In the first-generation study, a total of 33,321 CMP cases were registered, 20,780 men and 12,541 women, where the fully adjusted models showed HRs (99% CI) for all foreign-born men of 0.92 (0.86–0.98) and for women of 0.90 (0.83–0.98). For dilated CMP, the risk was higher for men from Nordic countries, more specifically men from Finland, and lower for men and women from Asia. For hypertrophic CMP, the risk was higher for men from Africa and Asia. For other types of CMPs, the risk was lower in men and women from Asia. In the second-generation study, a total of 26,559 cases were registered (17,620 men and 8939 women), with no significant differences overall or among specific groups, when Swedish-born with foreign-born parents were compared to Swedish-born with Swedish-born parents. Conclusions: We observed a generally lower risk of CMPs among foreign-born individuals, but with a higher risk especially for hypertrophic CMPs for men from Africa and Asia, and a higher risk of dilated CMP for men from Nordic countries.