Cardiovascular Manifestations in Systemic Lupus Erythematosus—Focus on Valvular Heart Disease and Non-Bacterial Thrombotic Endocarditis

We thank Drs Yavuz and Engin for their interest in our work, especially regarding the valvular manifestations of systemic lupus erythematosus (SLE).^1,2 It is important to note that SLE and antiphospholipid antibody syndrome (APS) are not mutually exclusive. ³ The diagnosis of APS relies on the revised Sapporo APS Classification Criteria (also called the Sydney criteria), whereas SLE diagnosis is based on either the American College of Rheumatology (ACR) or Systemic Lupus International Collaborating Clinics Criteria (SLICC).^4-7 Nonbacterial thrombotic endocarditis (NBTE) can be associated with either condition. ⁸

Although NBTE has commonly been referred to as “Libman-Sacks endocarditis,” the condition was identified before Libman and Sacks described four cases in 1924. ⁹ In 1888, Ziegler ¹⁰ identified sterile thrombi on cardiac valvular structures and named this finding thromboendocarditis. In 1899, Harbitz ¹¹ noticed the association of this finding with advanced stages of chronic illnesses including malignancies. The condition was thus referred to as terminal endocarditis. Thereafter, the condition has been named after Libman and Sacks following their detailed description of four cases with NBTE.^9,12

Our experience with NBTE, spanning over 20 years, has been recently published. ¹³ We presented the largest contemporary clinical cohort of NBTE patients (n = 42), highlighting the risk factors, symptomatic manifestations, laboratory and imaging evaluation, medical and surgical management, and clinical outcomes. ¹³ Despite the imperfect understanding of pathogenesis, multiple triggering factors with resultant endothelial injury and activation of inflammatory pathways have been proposed to lead to involvement of cardiac structures. ⁸ In line with the available literature, we found that the most common structure to be involved with NBTE is the mitral valve, followed by the aortic valve. ¹³ Clinical presentation varies widely and disease manifestations reflect primary valvular pathology or systemic thromboembolism.^13,14 Management is focused on therapeutic anticoagulation and, whenever appropriate in selected patients, operative valvular intervention.^13,15

There is a paucity of data on surgical management of NBTE, with no formal specific guideline recommendations on timing and choice of surgical strategy. We believe that surgical management should be individualized, and cases selected for valve repair vs replacement should be carefully scrutinized, taking into consideration patient-related factors, extent of valve involvement, underlying disease activity, and feasibility of valve repair. Patients with otherwise well-controlled systemic disease activity and repairable significant valve pathology, should be considered for valve repair at experienced centers. This is especially important in young patients where preservation of native valvular structures is desirable, if feasible. There are reported cases of repaired mitral valve insufficiency caused by NBTE that demonstrated no significant valvular pathology upon follow-up of up to almost 10 years. ¹⁶ Favoring mechanical over bioprosthetic prosthesis, when a native valve structure cannot be salvaged due to a concern of accelerated bioprosthetic valve inflammation and degeneration is based on limited data from case reports. ¹⁷ Despite this, if long-term anticoagulation therapy cannot be safely administered, and there is well-controlled concomitant disease activity, bioprosthetic valve replacement may be considered with careful follow-up.

Advanced evaluation, multi-specialty collaborative management, and mitigation of underlying systemic disease activity cannot be overemphasized to minimize the risk of future complications or prosthetic valve failure. Also important is the overall prognosis and the nature of the associated systemic condition. Patients with underlying malignancies tend to have poor prognosis, and thus, their management strategies are often different, including specific treatment of the underlying malignancies, where possible. ¹³ Therefore, a multidisciplinary approach with comprehensive assessment and tailored therapy should be practiced in evaluating and managing patients with SLE complicated by NBTE.