Having dermatomyositis or polymyositis would, in itself, be a risk factor for coronary artery disease, even if the underlying physiopathological mechanisms remain to be precisely identified. This is the conclusion of a study conducted in Taiwan. It focused on the health insurance data of 1,145 adults with myositis, compared to those of 732,723 control patients matched in age and gender, but also in cardiovascular risk factors.
More common ischemic heart disease
Published in March 2019, its results show:
- an incidence of coronary artery disease for dermatomyositis and polymyositis of 15.1 and 30.1 per 1000 person-years, respectively, versus 8.4 and 10.5 per 1000 person-years in the control group;
- an adjusted risk (hazard ratio or HR) of coronary artery disease of 2.21 for the dermatomyositis subgroup and 3.73 for the polymyositis subgroup compared to the control population.
A second study, conducted in Sweden, assessed the risk of occurrence of a first acute coronary syndrome in a cohort of 655 patients with dermatomyositis, polymyositis or inclusion body myositis, compared to a cohort of 6,813 control subjects. Released in March 2019 as well, its results show:
- an incidence of first acute coronary syndrome of 15.6 per 1000 person-years in case of myositis, with a hazard ratio (HR) of 2.4 compared to the general population;
- maximum excess risk within one year of diagnosis (HR 3.6), possibly due to high disease activity or introduction of immunosuppressants during this period;
- a higher than average increased risk of acute coronary syndrome (HR of 3) for women and patients aged 69-90 years;
- a first acute coronary syndrome occurring earlier in the myositis group than in the control group.
Other vessels to watch
Published in 2021, a meta-analysis of 22 observational studies in dermatomyositis and polymyositis leads to comparable conclusions. It reports a significant increase in the occurrence of coronary artery disease, but also of ischemic stroke and, above all, of thromboembolic disease with a risk multiplied by 5.53 of phlebitis and by 5.26 pulmonary embolism.
All these elements provide strong evidence of strengthening cardiovascular monitoring and prevention in patients with idiopathic inflammatory myopathy.
