Association of autoimmune diseases with cardiomyopathy: A nationwide follow-up study from Sweden

Aims: Certain autoimmune diseases (ADs), such as Crohn's disease and celiac diseases, have been linked to acute cardiovascular disorders. We examined whether there is an association between 43 different ADs and risk of subsequent hospitalization and mortality of cardiomyopathy in a nationwide follow-up study in Sweden. Methods and results: All individuals in Sweden hospitalized with a main diagnosis of an AD (n = 955 410) without previous or coexisting cardiomyopathy, between 1 January 1987 and 31 December 2018, were followed for hospitalization or mortality of cardiomyopathy. The reference population was the total population of Sweden. Standardized incidence ratios (SIRs) for cardiomyopathy were calculated. Overall risk of cardiomyopathy during the first year after hospitalization for an AD was 3.63 [99% confidence interval (CI) 3.29-4.00]. A total of 21 of the 43 ADs studied were associated with an increased risk of cardiomyopathy during the first year after hospitalization. The overall risk of cardiomyopathy decreased over time, from 1.18 (99% CI 1.12-1.25) after 1+ year to 1.07 (99% CI 0.96-1.19) after 5+ years. Females generally had higher SIRs than males. The ADs for which the SIRs of cardiomyopathy were highest after 1 year of hospitalization included Crohn's disease (1.92), rheumatoid arthritis (1.57), sarcoidosis (1.48), and psoriasis (1.31). Conclusion: Most ADs are associated with an increased risk of cardiomyopathy, particularly in the first year after hospital admission. Our findings show that many hospitalized ADs are tightly linked to cardiomyopathy but the mechanisms need to be further evaluated.