- The excess risk of cardiovascular (CV) events in idiopathic inflammatory myopathy (IIM) during the first 5 years following the diagnosis is similar to that found in rheumatoid arthritis (RA).
- The risk appears to return to that of the general population in IIM but not RA beyond the first 5 years.
Why this matters
- Guidelines on the assessment and management need to be developed to consider CV risk in IIM. This will reduce mortality in IIM, which remains high despite immunosuppressive treatment, with cardiac disease being a major cause of death.
- This retrospective, matched, population-based cohort study included 603 patients with IIM, 4047 with RA, and 4061 control participants using data from the UK Clinical Practice Research Datalink (CPRD) from 1987 to 2013.
- Main outcome: fatal and non-fatal first incident major CV events, including myocardial infarction (MI), acute coronary syndrome, unstable angina, or stroke.
- Funding: Medical Research Council.
- Compared with the control group, IIM and RA groups had a significantly higher risk of all CV events (HR, 1.47; 95% CI, 1.18-1.83 and HR, 1.36; 95% CI, 1.22-1.52, respectively)
- After adjustment for CV risk factors, CV events showed similar trends in IIM (aHR, 1.38; 95% CI, 1.11-1.72) and RA (aHR, 1.26; 95% CI, 1.12-1.41), with a non-significant difference between the two diseases.
- The risk of CV events in IIM was most apparent in the first 5 years (HR, 1.32; 95% CI, 0.90-1.95), and reduced in the 5-10 (HR, 0.74; 95% CI, 0.32-1.69) and 10-15 year period (HR, 1.03; 95% CI, 0.57-1.84).
- In patients with RA, the risk difference was more stable over time:
- first 5 years (HR, 1.22; 95% CI, 0.91-1.65);
- 5-10 years (HR, 1.22; 95% CI, 0.92-1.63); and
- 10-15 years (HR, 1.31; 95% CI, 1.05-1.65).
- The risk of MI (HR, 1.61; 95% CI, 1.27-2.04) but not stroke (HR, 0.88; 95% CI, 0.56-1.39) was significantly higher in the IIM vs control group.
- Retrospective design.
- Risk of case ascertainment and survivorship bias.