People with autoimmune diseases have a higher risk of developing cardiovascular disease

People with autoimmune diseases have a higher risk of developing cardiovascular disease

Around ten percent of the population in high-income regions such as Europe and the United States have been diagnosed with one or more autoimmune diseases. Examples include rheumatoid arthritis, psoriasis, systemic sclerosis, lupus erythematosus and type I diabetes. Although previous research has suggested associations between some of these conditions and a higher risk of cardiovascular disease, these studies have often been too small and limited to selected autoimmune diseases or selected cardiovascular diseases to provide conclusive evidence for the need for cardiovascular disease prevention in patients with autoimmune diseases.

Until now. At the annual congress of the European Society of Cardiology, held this weekend in Barcelona, ​​an international research team led by KU Leuven presented the result of a thorough epidemiological investigation into possible links between nineteen of the most common autoimmune diseases and cardiovascular diseases. The results of the study show that patients with autoimmune diseases have a significantly higher risk (between 1.4 and 3.6 times, depending on the autoimmune disease) of developing cardiovascular diseases than people without autoimmune diseases. This increased risk is comparable to that of type 2 diabetes, a known risk factor for cardiovascular disease. Research shows for the first time that cardiovascular risks affect autoimmune diseases as a group of diseases and not just selected diseases individually.

The entire spectrum of cardiovascular diseases

In the research (published in The Lancet), the authors show that the group of nineteen autoimmune diseases they studied account for about 6 percent of cardiovascular events. Importantly, excess cardiovascular risk was evident across the spectrum of cardiovascular disease, beyond classic coronary artery disease, including infection-related heart disease, cardiac inflammation, and thromboembolic and degenerative heart disease, suggesting that the impact of autoimmunity on cardiovascular health is likely to be much broader than originally thought. Furthermore, the increased risk was not explained by traditional cardiovascular risk factors such as age, gender, socioeconomic status, blood pressure, BMI, smoking, cholesterol and type 2 diabetes. Another notable finding: the excess risk is particularly high in patients with autoimmune diseases under the age of 55, suggesting that autoimmune diseases are particularly important in the development of premature cardiovascular disease, with the potential to lead to disproportionate years of life lost and disability.

The study was based on electronic patient records from the UK's Clinical Practice Research Datalink (CPRD), a very large database containing anonymised patient data from around a fifth of the current UK population. From 22 million patient records, researchers assembled a cohort of patients newly diagnosed with one of nineteen autoimmune diseases. They then examined the incidence of 12 cardiovascular outcomes – an unprecedented level of granularity made possible by the very large size of the data set – over the following years and compared them to a matched control group. The risk of developing cardiovascular disease was on average 1.56 times higher in patients with one or more autoimmune diseases than in patients without autoimmune diseases. They also found that the risk of excess increased with the number of different autoimmune diseases in individual patients. The diseases with the highest excess risk included systemic sclerosis, Addison's disease, lupus and type I diabetes.

Need for targeted prevention measures

The results show a need for action, says Nathalie Conrad, lead author of the study. "We see that the additional risk is comparable to that of type 2 diabetes. But although we have specific interventions targeting diabetes patients to reduce their risk of developing cardiovascular disease (in terms of prevention and follow-up), we do not have similar interventions for patients with autoimmune diseases." Conrad mentions the European Society of Cardiology guidelines on cardiovascular disease prevention, which do not yet mention autoimmunity as a cardiovascular risk factor (the guidelines only mention some specific diseases such as Lupus) and also do not list specific preventive measures for patients with autoimmune disease.

Conrad hopes the study will raise awareness among patients with autoimmune diseases and clinicians involved in the care of these patients, including many different specialties such as cardiologists, rheumatologists or general practitioners. "We need to develop targeted prevention measures for these patients. And we need to do further research to help us understand why patients with an autoimmune disease develop more cardiovascular disease than others and how we can prevent this."

Speaking of pathophysiology, the underlying mechanisms are still poorly understood. Conrad: "The general hypothesis is that chronic and systemic inflammation, which is a common denominator in autoimmune diseases, can trigger all types of cardiovascular diseases. The effects of autoimmune diseases on connective tissue, small vessels and cardiomyocytes, and perhaps some of the treatments commonly used to treat autoimmune diseases, are also likely to contribute to patients' cardiovascular risk. This really needs to be thoroughly investigated."

Conrad, who holds an engineering degree and a doctorate in medical sciences (epidemiology), conducted the study during a two-year Marie Curie postdoctoral fellowship at KU Leuven. She worked closely with Professor Geert Verbeke (KU Leuven), Professor Geert Molenberghs (KU Leuven and Hasselt University) and Professor Jan Verbakel (KU Leuven), who assisted with the biostatistical and clinical side of the study. Also part of the team was John McMurray (University of Glasgow, UK), a world-renowned cardiologist. He praises the very broad spectrum of research. “This population-based study suggests that a much broader range of autoimmune diseases than previously thought are associated with a variety of different cardiovascular problems.” The cardiologist further mentions a possible short-term solution. “Some of these problems may be preventable through readily available treatments such as statins.”

Source:

KU Lions

Reference:

Conrad, N., et al. (2022) Autoimmune diseases and cardiovascular risk: a population-based study of 19 autoimmune diseases and 12 cardiovascular diseases in 22 million people in the UK. The lancet. doi.org/10.1016/S0140-6736(22)01349-6.

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