Introduction

What is Lupus?

Lupus, medically known as systemic lupus erythematosus (SLE), is a chronic autoimmune disease that can affect various parts of the body, including the skin, joints, kidneys, heart, lungs, and brain. In lupus, the immune system mistakenly attacks healthy tissues and organs, leading to inflammation, pain, and damage. This condition can vary widely in severity and can be challenging to diagnose due to its diverse range of symptoms and the fluctuating nature of the disease.¹

Different types of Lupus

• Systemic Lupus Erythematosus (SLE): This is the most common form of lupus and can affect multiple organs and systems within the body. Symptoms can range from mild to severe, including fatigue, joint pain, skin rashes, fever, and organ involvement. 
• Cutaneous Lupus Erythematosus (CLE): This type of lupus primarily affects the skin, causing various rashes and lesions. Subtypes of CLE include discoid lupus erythematosus (DLE), which typically involves coin-shaped lesions on the skin, and subacute cutaneous lupus erythematosus (SCLE), characterised by scaly patches or red circular lesions on sun-exposed areas.
• Drug-induced Lupus: Certain medications, particularly those used to treat conditions like hypertension and seizures, can trigger lupus-like symptoms in some individuals. These symptoms often resolve once the medication is discontinued. 
• Neonatal Lupus: This rare form of lupus occurs in newborn infants whose mothers have certain autoantibodies. Neonatal lupus can cause skin rashes, liver problems, and less commonly, heart defects in newborns. However, these symptoms usually disappear within a few months after birth, and the condition does not typically recur in subsequent pregnancies.

Understanding the different types of lupus is crucial for accurate diagnosis and appropriate management of the disease. Each type may present with distinct symptoms and require tailored treatment approaches.²

Prevalence of cardiovascular manifestations

Statistics and prevalence rates

Cardiovascular manifestations are a significant concern in lupus patients, contributing to increased morbidity and mortality rates. According to various studies, the prevalence of cardiovascular complications in systemic lupus erythematosus (SLE) patients ranges from 6% to 75%, depending on factors such as disease duration, severity, and patient demographics.³

Risk factors

Several risk factors contribute to the development of cardiovascular manifestations in lupus patients. These include traditional cardiovascular risk factors such as hypertension, hyperlipidemia, smoking, obesity, and diabetes mellitus. Additionally, lupus-specific factors such as disease activity, duration, and presence of lupus anticoagulant and anti-phospholipid antibodies play significant roles in predisposing patients to cardiovascular complications.⁴

Types of cardiovascular manifestations

• Pericarditis: The inflammation of the pericardium (the thin sac surrounding the heart), is a common cardiovascular manifestation in lupus patients. It can present with symptoms such as chest pain, which may worsen with deep breathing or lying flat, fever, and a friction rub heard on auscultation. Pericarditis in lupus can be acute or chronic and may lead to complications such as pericardial effusion and cardiac tamponade if left untreated⁵
•  Myocarditis: Inflammation of the myocardium (the muscular layer of the heart), is another cardiac manifestation observed in lupus patients. It can manifest with symptoms such as chest pain, shortness of breath, palpitations, and fatigue. Myocarditis in lupus may lead to impaired cardiac function and heart failure if not managed promptly⁶
• Endocarditis: Inflammation of the endocardium (the inner lining of the heart chambers and valves), can occur in lupus patients, particularly those with Libman-Sacks endocarditis. This condition is characterised by the formation of lumps on the heart valves, which may predispose individuals to valvular dysfunction, embolic events, and infective endocarditis⁷
• Coronary Artery Disease (CAD):  Characterised by the narrowing or blockage of coronary arteries supplying blood to the heart muscle. Chronic inflammation, endothelial dysfunction, and traditional cardiovascular risk factors contribute to the development of CAD in lupus. Patients may present with symptoms such as angina, shortness of breath, and in severe cases myocardial infarction (heart attack)⁸
• Vasculitis: Inflammation of blood vessels, which can affect both large and small vessels in lupus patients, leading to cardiovascular complications. This may include vasculitis of the coronary arteries, resulting in myocardial ischemia and infarction, as well as vasculitis of peripheral arteries and veins, causing peripheral vascular disease and thrombosis.

Understanding these cardiovascular manifestations is crucial for timely recognition, diagnosis, and management to prevent serious complications and improve outcomes in lupus patients.⁹

Mechanisms underlying cardiovascular involvement in Lupus

Immune dysregulation

Immune dysregulation plays a central role in the pathogenesis of cardiovascular involvement in lupus. In systemic lupus erythematosus (SLE), the immune system mistakenly targets self-antigens, leading to the production of autoantibodies and immune complex deposition in various tissues, including the cardiovascular system. Dysregulated immune responses, such as abnormal T and B cell activation, cytokine production, and complement activation, contribute to endothelial dysfunction, vasculitis, and tissue damage in the heart and blood vessels.¹⁰

Inflammation

Chronic inflammation is a hallmark feature of lupus and contributes to cardiovascular complications through multiple mechanisms. Inflammatory mediators, including cytokines, chemokines, and adhesion molecules, promote endothelial dysfunction, smooth muscle cell proliferation, and plaque formation in the arterial walls. Persistent inflammation also exacerbates atherosclerosis, destabilises atherosclerotic plaques, and increases the risk of acute cardiovascular events such as myocardial infarction and stroke in lupus patients.¹¹

Autoantibodies

The presence of autoantibodies targeting self-antigens is a characteristic feature of lupus and contributes to cardiovascular pathology. Autoantibodies such as anti-phospholipid antibodies (e.g., anti-cardiolipin antibodies, lupus anticoagulant) promote thrombosis, endothelial dysfunction, and accelerated atherosclerosis in lupus patients. Additionally, autoantibodies targeting components of the cardiac tissue, such as anti-endothelial cell antibodies and anti-myocardial antibodies, contribute to myocardial inflammation, fibrosis, and dysfunction.¹²

Signs and symptoms

The clinical presentation of cardiovascular involvement in lupus can vary widely and may include symptoms such as chest pain, shortness of breath, palpitations, fatigue, and peripheral oedema. These symptoms may result from various cardiac manifestations, including pericarditis, myocarditis, endocarditis, coronary artery disease, and vasculitis. Additionally, lupus patients may be asymptomatic or present with atypical symptoms, making the diagnosis challenging. A thorough clinical evaluation, including a detailed medical history, physical examination, and appropriate diagnostic tests (e.g. echocardiography, electrocardiography, cardiac biomarkers), is essential for the timely detection and management of cardiovascular complications in lupus.¹³

Treatment

Medications

• Immunosuppressants: Immunosuppressive medications play a crucial role in managing cardiovascular involvement in lupus by suppressing abnormal immune responses and reducing inflammation. Commonly used immunosuppressants in lupus include corticosteroids, which help control disease activity and alleviate symptoms of pericarditis, myocarditis, and vasculitis. Additionally, other immunosuppressive agents such as methotrexate, azathioprine, mycophenolate mofetil, and cyclophosphamide may be prescribed in severe cases of refractory disease to control inflammation and prevent organ damage.
• Anti-inflammatory drugs: Non-steroidal anti-inflammatory drugs (NSAIDs) are often used to relieve symptoms of pericarditis, arthritis, and pleurisy in lupus patients. However, caution should be exercised in their use due to the potential risk of adverse effects, particularly on the gastrointestinal and renal systems. Selective NSAIDs with lower gastrointestinal and renal toxicity profiles may be preferred in lupus patients with cardiovascular involvement¹⁴
• Antimalarial agents: Hydroxychloroquine, an antimalarial medication, has emerged as a cornerstone of therapy in lupus management due to its immunomodulatory and anti-inflammatory properties. Hydroxychloroquine has been shown to reduce disease activity, prevent flares, and improve long-term outcomes in lupus patients, including those with cardiovascular manifestations. It may also benefit lipid profiles and reduce the risk of thromboembolic events in lupus¹⁵
• Antiplatelet and anticoagulant therapy: Lupus patients with antiphospholipid syndrome (APS) or a history of thromboembolic events may require antiplatelet (e.g., aspirin) or anticoagulant therapy (e.g., warfarin, direct oral anticoagulants (DOACs)) to prevent thrombosis and thromboembolic complications. These medications help mitigate the prothrombotic state associated with APS and reduce the risk of myocardial infarction, stroke, and venous thromboembolism in lupus patients¹⁵

Lifestyle modifications

• Diet: A healthy, balanced diet is essential for managing cardiovascular risk factors and optimising overall health in lupus patients. Emphasis should be placed on consuming various nutrient-rich foods, including fruits, vegetables, whole grains, lean proteins, and healthy fats. Limiting the intake of processed foods, saturated fats, cholesterol, and sodium can help reduce the risk of hypertension, dyslipidemia, and obesity in lupus patients. Additionally, omega-3 fatty acids found in fatty fish, flaxseeds, and walnuts may have anti-inflammatory properties and cardiovascular benefits in lupus.
• Exercise: Regular physical activity is beneficial for cardiovascular health and can help improve muscle strength, endurance, and flexibility in lupus patients. Low-impact exercises such as walking, swimming, cycling, and yoga are generally well-tolerated and can be tailored to individual preferences and capabilities. Exercise programs should be started gradually and modified as needed based on disease activity, joint involvement, and overall functional status in lupus patients.
• Smoking cessation: Smoking is a major modifiable risk factor for cardiovascular disease and can exacerbate inflammation, endothelial dysfunction, and atherosclerosis in lupus patients. Smoking cessation interventions, including behavioural counselling, pharmacotherapy, and support groups, should be offered to lupus patients who smoke to reduce the risk of cardiovascular complications and improve long-term outcomes.¹⁶

Future directions

Further research is needed to elucidate the underlying pathophysiological mechanisms driving cardiovascular complications in lupus. Investigating the interplay between immune dysregulation, inflammation, endothelial dysfunction, and traditional cardiovascular risk factors may uncover novel therapeutic targets and biomarkers for early detection and intervention. Well-designed clinical trials are essential for evaluating the safety and efficacy of emerging treatments for lupus-related cardiovascular manifestations. Large-scale, multicenter trials with standardised endpoints and long-term follow-up are needed to establish evidence-based guidelines and advance clinical practice in this field. Translating basic science discoveries into clinical applications is critical for translating promising experimental therapies into effective treatments for lupus patients. Collaborative efforts between basic scientists, clinicians, and industry partners are necessary to bridge the gap between bench and bedside and accelerate the development of innovative therapies for lupus.