Background

Certain autoimmune diseases are associated with an increased risk of cardiovascular disease. We sought to determine whether or not this is true, and to what extent, for a wide range of autoimmune diseases.

Methods

In this population-based study, we used linked primary and secondary care records from the Clinical Practice Research Datalink (CPRD), GOLD and Aurum datasets, to assemble a cohort of individuals across the UK who have been newly diagnosed with one of 19 autoimmune diseases between January 1, 2000 and December 31, 2017, under the age of 80 at diagnosis, and free of cardiovascular disease until 12 months after diagnosis. We also assembled a matched cohort with up to five individuals matched on age, sex, socioeconomic status, region, and calendar year, who were free of autoimmune disease and free of cardiovascular disease until at 12 months after entry into the study. Both cohorts were followed until June 30, 2019. We studied the incidence of 12 cardiovascular outcomes and used Cox proportional hazards models to examine differences between patients with and without autoimmune diseases.

Results

Of 22,009,375 individuals identified from CPRD databases, we identified 446,449 eligible individuals with autoimmune diseases and 2,102,830 matched controls. In the autoimmune cohort, the mean age at diagnosis was 46 2 years (SD 19 8), and 271,410 (60 8%) were female and 175,039 (39 2%) were men. 68,413 (15 3%) people with and 231,410 (11 0%) without autoimmune diseases developed incident cardiovascular disease over a median of 6 2 years (IQR 2 7–10 8 ) feedback. The incidence rate of cardiovascular disease was 23 3 events per 1000 patient-years in patients with autoimmune disease and 15 0 events per 1000 patient-years in those without autoimmune disease (risk relative [HR] 1 56 [95% CI 1·52–1·59]). An increased risk of cardiovascular disease with autoimmune disease was observed for each individual cardiovascular disease and increased progressively with the number of autoimmune diseases present (a disease: HR 1 41
[95% CI 1·37–1·45]; two diseases: 2 63 [2·49–2·78]); three or more illnesses: 3 79
[3·36–4·27]), and in younger age groups (age

Interpretation

These results warrant targeted cardiovascular preventive measures, particularly in young patients with autoimmune diseases, and further research into the pathophysiological mechanisms underlying these complications.

Funding

Horizon 2020 Marie Skłodowska-Curie Actions and European Society of Cardiology.