About 10% of the population in the richest countries have been diagnosed with one or more autoimmune disorders, such as rheumatoid arthritis, psoriasis, systemic sclerosis, lupus erythematosus and type I diabetes. Although previous research had already suggested the existence of associations between some of these disorders and an increased risk of cardiovascular disease, these studies were often too small and limited to selected autoimmune or cardiovascular conditions to obtain conclusive evidence on the need to prevent cardiovascular disease among patients with autoimmune diseases, until now. At the annual congress of the European Society of Cardiology, held in Barcelona, a team led by the Catholic University of Louvain (Belgium) has presented the result of an exhaustive epidemiological investigation into the possible links between 19 of the most common autoimmune disorders and the sick cardiovascular diseases.
And their results show that patients with autoimmune diseases have a substantially higher risk (between 1.4 and 3.6 times, depending on which autoimmune disease) of developing cardiovascular disease than those without an autoimmune disorder. This increased risk is comparable to that of type 2 diabetes, a known risk factor for cardiovascular disease.
The research demonstrates for the first time that cardiovascular risks affect autoimmune diseases as a group of disorders, and not selected disorders individually.
The implications of autoimmunity for cardiovascular health are much broader than originally thought
The study, which will be published in the journal “The Lancet”, indicates that the group of 19 autoimmune disorders that have been studied represents around 6% of cardiovascular events.
Importantly, excess cardiovascular risk was visible across the spectrum of cardiovascular disease, beyond classic coronary heart disease, including infection-related cardiac disorders, heart inflammation, as well as thromboembolic heart disorders and degenerative, suggesting that the implications of autoimmunity on cardiovascular health are probably much broader than originally thought.
In addition, the excess risk was not explained by traditional cardiovascular risk factors, such as age, gender, socioeconomic status, blood pressure, body mass index (BMI), smoking, cholesterol, or type 2 diabetes. .
Another noteworthy finding is that the excess risk is especially high among patients with autoimmune disorders younger than 55 years and suggests that autoimmune diseases are especially important for the premature onset of cardiovascular disease, with the potential to cause a disproportionate loss of years of life and possible disability.
The study was based on electronic health records from the Clinical Practice Research Datalink (CPRD) of the United Kingdom, a very large database of anonymous patient data from around a fifth of the current UK population. From 22 million patient records, the researchers assembled a cohort of patients who had recently been diagnosed with one of 19 autoimmune disorders.
The excess risk is especially high among patients with autoimmune disorders younger than 55 years.
They then analyzed the incidence of 12 types of cardiovascular events – made possible by the large size of the data set – in the following years, and compared it with a matched control group.
They also found that the excess risk increased with the number of different autoimmune disorders in each patient. Among the disorders with the highest excess risk were systemic sclerosis, Addison’s disease, lupus and type I diabetes.
The results show that action is needed, says Nathalie Conrad, lead author of the study. “We see that the excess risk is comparable to that of type 2 diabetes. But although we have specific measures aimed at patients with diabetes to reduce their risk of developing cardiovascular disease (in terms of prevention and monitoring), we do not have any similar measures. for patients with autoimmune disorders.
Conrad mentions the European Society of Cardiology guidelines on the prevention of cardiovascular diseases, which still do not mention autoimmunity as a cardiovascular risk factor (the guidelines only mention a few specific disorders, such as lupus) nor do they list any specific prevention measures for patients with autoimmune diseases.
Chronic and systemic inflammation, which is a common denominator in autoimmune disorders, can trigger all kinds of cardiovascular diseases
Conrad hopes the study will serve to raise awareness among patients with autoimmune diseases and clinicians involved in caring for these patients, who include many different specialties, such as cardiologists, rheumatologists, or general practitioners. “We have to develop specific prevention measures for these patients. And we need further research to understand why patients with an autoimmune disorder develop more cardiovascular disease than others, and how we can prevent this from happening.”
Regarding the pathophysiology, the underlying mechanisms remain poorly understood.
According to Conrad, “The general hypothesis is that chronic and systemic inflammation, which is a common denominator in autoimmune disorders, can trigger all types of cardiovascular disease.” It is likely that the effects of autoimmune disease on connective tissues, small vessels, and cardiomyocytes, and possibly some of the therapies commonly used to treat autoimmunity, also contribute to patients’ cardiovascular risk. This needs to be thoroughly investigated.”