THE IMPORTANCE OF TRANS-ESOPHAGEAL ECHOCARDIOGRAPHY IN DIAGNOSING LIBMAN-SACKS ENDOCARDITIS IN SYSTEMIC LUPUS ERYTHEMATOSUS: A CASE REPORT

PV304 / #276 Case Report Poster Topic: AS23 - SLE-Diagnosis, Manifestations, & Outcomes Introduction Libman-Sacks endocarditis (LSE), a form of nonbacterial thrombotic endocarditis (NBTE), is characterized by fibrinous, sterile vegetations, favoring the mitral and aortic valves. LSE is observed in up to 11% of patients with systemic lupus erythematosus (SLE) as 1 of 2 major valvular manifestations, the other being thickening, with both mechanisms contributing to valvular dysfunction. LSE may typically be clinically silent, but predisposes to greater risk of cerebrovascular disease, underpinning the importance of its recognition. Complicating this, LSE may be clinically mimicked by infectious endocarditis; both may present with arterial embolism and may share elevated inflammatory markers and positive autoantibodies. Here, we present a complex first presentation of SLE with LSE resulting in cerebrovascular disease in a young patient. This case reinforces the importance of trans-esophageal echocardiography (TEE) in differentiating morphological features of NBTE from infectious endocarditis to guide timely management. Case Presentation With Investigation A 22-year-old male of fit-and-well background presented with progressive lower limb swelling and right upper limb weakness. Broad-spectrum intravenous antibiotics were commenced for suspected infectious endocarditis, given trans-thoracic echocardiography (TTE) findings of moderate mitral regurgitation, magnetic resonance imaging (MRI) brain evidence of multiple embolic strokes (Figure 1), and progressive kidney injury with microscopic hematuria. Characteristic findings of LSE unseen on TTE were visualized by TEE: sessile posterior mitral valve leaflet tip lesions and thickening of the leaflets (Figure 2). This supported the clinical suspicion of NBTE, reinforced by persistent culture negativity. Laboratory tests confirmed positive antinuclear and double-stranded DNA antibodies, compatible with a first presentation of SLE, featuring cerebrovascular disease, LSE and lupus nephritis. Early TEE findings supported multidisciplinary team agreement to switch from intravenous antibiotics to high-dose corticosteroids. Figure 1. Figure 2. Literature Review LSE is an under-reported manifestation of SLE and is 1 of 2 mechanisms whereby lupus may affect the heart valves, alongside valvular thickening. SLE patients with neurological sequelae and high index of suspicion for NBTE should first undergo TTE to assess for valvular thickening or vegetations, as their presence relates to 3-fold greater numbers of circulating cerebral microemboli and subsequent cerebrovascular disease.[1] Trans-thoracic imaging, however, underestimates lupus-associated valve disease, and poorly differentiates NBTE from infective endocarditis. No individual biochemical test can confirm LSE; imaging must therefore play a vital role in differentiation. Importantly, 3-dimensional TEE possesses greater sensitivity and specificity than TTE and 2-dimensional TEE for visualization of LSE vegetations.[2] LSE-related valvular masses may be differentiated from bacterial vegetations based on their appearance, mobility, and location. Libman-Sacks vegetations are sessile, typically smaller (<10mm), are heterogeneous in echotexture, may show central calcification, and are visualized at the leaflet base. Conversely, bacterial lesions are homogenous in echotexture, are found at the line of leaflet closure, and move independently from the motion of the valve.[3] In our patient, we observed typical features of NBTE, namely valvular thickening (Figure 2a) and multiple small, sessile lesions (Figure 2b) correlating with his extracardiac manifestations of lupus including cerebrovascular disease (Figure 1). Discussion Our case highlights the importance of trans-esophageal echocardiography in the diagnosis of SLE-related LSE and differentiation from infective endocarditis, which may mimic NBTE clinically and biochemically. TEE may complement trans-thoracic imaging in diagnosing NBTE to identify a subset of patients with SLE at greatest risk of cerebrovascular disease who may benefit from intensive immunosuppression. References: [1.] Roldan CA. JACC Cardiovasc Imaging 2013;6(9):973-83. [2.] Roldan CA. J Am Soc Echocardiogr 2015;28(7):770-9. [3.] Kato T. CASE (Phila) 2020;4(6):507-511.