Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease where the immune system mistakenly attacks its own tissues. Because this condition is systemic, it can cause inflammation and damage in nearly any organ system, including the heart and the surrounding blood vessels. Cardiovascular complications represent a significant concern for individuals with SLE and have become a leading cause of illness and mortality within this patient population. Understanding how lupus affects the heart is important for both patients and healthcare providers to ensure early detection and management of these complications.
Pericarditis: The Most Frequent Cardiac Finding
The most commonly identified cardiac disorder associated with Systemic Lupus Erythematosus is pericarditis, which is the inflammation of the pericardium. The pericardium is a thin, two-layered sac surrounding the heart, helping to anchor and protect it within the chest cavity. When the immune system targets this structure, the inflammation causes irritation and swelling of the layers.
This inflammation can lead to an accumulation of excess fluid within the sac, a condition known as pericardial effusion. While many cases of pericarditis in lupus patients remain clinically silent, others can present with noticeable symptoms. Symptomatic pericarditis is reported in approximately 20 to 25% of SLE patients, though evidence of pericardial involvement may be found in over 50% of patients when using sensitive imaging techniques like echocardiography.
Pericarditis often develops early in the course of the disease and is frequently associated with heightened lupus activity. Although the condition is typically mild and resolves within a few months, a subset of patients may experience chronic or recurring episodes. In rare, severe instances, the rapid accumulation of fluid can compress the heart, leading to a life-threatening condition called cardiac tamponade.
Autoimmune Mechanisms of Cardiac Damage
The damage to the heart in SLE stems from the autoimmune process, which involves an immune response against the body’s own structures. The immune system produces autoantibodies, such as anti-double-stranded DNA (anti-dsDNA) and antiphospholipid antibodies, that circulate throughout the body. These autoantibodies combine with self-antigens to form immune complexes, which then deposit in different tissues of the heart, including the pericardium, myocardium, and heart valves.
This deposition triggers a localized inflammatory reaction, leading to damage in multiple cardiac structures. The chronic inflammation and immune complex deposition are thought to drive accelerated atherosclerosis, which is the premature buildup of plaque in the coronary arteries. This is a major long-term consequence of lupus, increasing the risk of heart attacks and strokes, particularly in younger women.
Furthermore, the deposition of immune complexes and the presence of antiphospholipid antibodies are closely linked to valvular heart disease, specifically Libman-Sacks endocarditis. This involves the formation of sterile, wart-like growths, called vegetations, on the heart valves, most often the mitral and aortic valves. Although these vegetations are often clinically silent, they can sometimes cause significant valve dysfunction, leading to leakage or narrowing. They may also increase the risk of blood clots traveling to the brain.
Recognizing Symptoms and Diagnostic Tools
Patients with SLE should be aware of symptoms that may signal cardiac involvement, though manifestations can be subtle or non-existent in many cases. The most characteristic symptom of acute pericarditis is sharp chest pain that may worsen with deep breathing, coughing, or when lying flat. Patients often find that the pain improves when they sit up and lean forward.
Other signs of heart trouble include shortness of breath, unusual fatigue, and a rapid or irregular heart rhythm, which can be associated with inflammation of the heart muscle (myocarditis). Any new or unexplained chest discomfort or change in exercise tolerance warrants prompt medical attention.
Clinicians use several diagnostic tools to assess the heart in lupus patients:
- A physical examination may reveal a pericardial friction rub, an audible sign of pericardial inflammation.
- An electrocardiogram (EKG) can show characteristic changes associated with pericarditis.
- A chest X-ray can detect a large pericardial effusion.
- The echocardiogram, an ultrasound of the heart, is the most commonly used tool to visualize the pericardium, measure the amount of fluid, and assess for valvular vegetations and heart muscle function.
- Blood tests, including markers of inflammation and lupus disease activity (like the SLEDAI-2K score) and specific autoantibody panels, help confirm the diagnosis and assess the severity of the underlying systemic disease.
Management of Lupus-Related Heart Conditions
The primary goal in managing lupus-related heart conditions is to control the underlying systemic inflammation that drives the cardiac damage. This involves the use of immunosuppressive and anti-inflammatory medications to dampen the immune response. Corticosteroids are frequently used to treat acute inflammation, particularly in cases of symptomatic pericarditis and myocarditis, often alongside nonsteroidal anti-inflammatory drugs (NSAIDs) for pain and inflammation control.
Long-term management often includes antimalarial drugs, such as hydroxychloroquine, which help control lupus disease activity and may offer protective cardiovascular benefits. For more severe or persistent inflammation, stronger immunosuppressants like azathioprine or mycophenolate mofetil may be incorporated into the treatment plan.
Managing the long-term risk of accelerated atherosclerosis requires diligent control of traditional cardiovascular risk factors, which are amplified by lupus. This includes strict blood pressure control, aggressive management of high cholesterol with statin medications, and lifestyle modifications such as maintaining a heart-healthy diet and regular physical activity. Patients with antiphospholipid antibodies or Libman-Sacks endocarditis may also require blood thinners to prevent dangerous clot formation and reduce the risk of stroke.