Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease characterized by the immune system mistakenly attacking its own healthy tissues. This systemic attack generates chronic inflammation that can affect nearly any organ, and the heart is a frequent target. Cardiac involvement is common in SLE patients, and cardiovascular disease has become a leading cause of illness and death. Understanding how this inflammation manifests in the heart’s structure—from its outer sac to its valves and blood vessels—is important for early detection and effective management.
Damage to the Heart Sac and Muscle
The most frequent cardiac manifestation of lupus is pericarditis, which is the inflammation of the pericardium, the thin, fluid-filled sac surrounding the heart. This condition affects an estimated 20% to 40% of SLE patients and often presents with a distinctive sharp chest pain. The pain typically worsens when lying flat or taking a deep breath and may be relieved by leaning forward.
Inflammation can cause an excessive buildup of fluid within the sac, known as a pericardial effusion. If this fluid accumulates rapidly or in large amounts, it can put pressure on the heart, restricting its ability to fill with blood (cardiac tamponade). Treatment for pericarditis usually involves anti-inflammatory medications to reduce the swelling and manage the symptoms.
A less common but more severe complication is myocarditis, which involves inflammation of the myocardium, or the heart muscle itself. This inflammation can weaken the heart’s ability to pump effectively, potentially leading to heart failure or disturbances in heart rhythm. Damage to the muscle tissue can be permanent, requiring prompt diagnosis and intensive immunosuppressive treatment.
Valve and Inner Lining Inflammation
Lupus can also directly target the endocardium, the delicate inner lining of the heart, and the heart valves. The unique form of valve disease associated with SLE is known as Libman-Sacks endocarditis, also called nonbacterial thrombotic endocarditis. This condition is characterized by the growth of sterile, wart-like deposits, or vegetations, on the heart valves.
These growths are composed of immune complexes, fibrin, and blood platelets, developing in the absence of a bacterial infection. The vegetations most frequently appear on the left-sided valves, particularly the mitral valve and the aortic valve. While often clinically silent, these deposits can cause the valve leaflets to thicken, leading to dysfunction such as regurgitation (leaking) or, less often, stenosis (narrowing).
A significant risk associated with Libman-Sacks endocarditis is the potential for these vegetations to dislodge and travel through the bloodstream. These fragments, acting as emboli, can cause blockages in other organs, most notably leading to stroke if they travel to the brain. The presence of antiphospholipid antibodies, often found in SLE patients, is strongly associated with the development of these vegetations and the increased stroke risk.
Accelerated Vascular Disease
The most life-threatening cardiac complication for patients with lupus is the accelerated development of atherosclerosis, the hardening and narrowing of the arteries. This is the underlying cause of coronary artery disease (CAD), heart attacks, and stroke, and it is the leading cause of death in SLE survivors. Unlike the general population, where traditional risk factors primarily drive atherosclerosis, lupus-related inflammation is a major independent factor.
Chronic, systemic inflammation inherent to lupus disrupts the normal function of the endothelium, the inner lining of blood vessels, initiating rapid plaque formation. Lupus-specific factors, including the presence of autoantibodies and ongoing immune system activity, significantly contribute to this vascular damage. This process means that many SLE patients develop significant coronary artery disease at a much younger age than their peers without the condition.
The risk is particularly pronounced in younger women with lupus, who may face a risk of heart attack that is many times higher than that of age-matched women in the general population. This excess risk is not fully accounted for by factors like high blood pressure or high cholesterol alone, highlighting the unique inflammatory mechanism at play. Aggressive management of both lupus disease activity and cardiovascular risk factors is required to mitigate this heightened danger.
Screening and Management of Cardiac Complications
Given the high prevalence of heart involvement, regular cardiac screening is an important component of lupus care, even in patients without obvious symptoms. Diagnostic tools such as electrocardiograms (ECG), echocardiograms, and sometimes cardiac magnetic resonance imaging (MRI) are used to detect early signs of pericardial effusion, valve abnormalities, or changes in heart muscle function. Traditional cardiovascular risk calculators often underestimate the true risk in SLE patients, necessitating a more proactive approach.
The primary strategy for managing lupus-related heart complications is the aggressive control of the underlying systemic inflammation and disease activity. Many of the medications used to treat lupus also offer protection for the heart; for instance, hydroxychloroquine has been shown to reduce cardiovascular risk and improve survival in SLE patients. Beyond treating the lupus itself, physicians must also manage all traditional risk factors with greater intensity, including stringent control of blood pressure and cholesterol levels. This often requires medication and lifestyle modifications to achieve targets that are lower than those set for the general population.