Libman-Sacks endocarditis in a Bangladeshi patient suffering from rhupus

Introduction

In Libman-Sacks endocarditis (LSE), the mitral and aortic valves are commonly involved, but any valve as well as endocardial surfaces may be affected. ¹ Asymptomatic cases may be discovered at routine echocardiography. Treatment is directed towards the underlying cause, preventing embolism and may require surgery.^1,2

Case report

A 34-year-old Bangladeshi woman, diagnosed with rheumatoid arthritis (RA), who had a previous cerebral infarction (Figure 1), was referred for echocardiography. During evaluation at our centre, she had no specific complaints. She was not taking contraceptive medications nor recreational drugs. She had no adverse pregnancy outcomes nor thrombotic episodes; she had no known valvular heart disease or family history of such. OPEN IN VIEWER

On examination she was pale with evidence of left hemi-paresis. She had grade 3/5 tenderness in all metacarpo-phalangeal and proximal inter-phalangeal joints. Precordial findings were essentially normal.

Investigations revealed a low haemoglobin (Hb = 10.5 g), normal white cell counts and slightly reduced platelet count (130 × 10⁹/L). Erythrocyte sedimentation rate (ESR) was 30 mm/1st h and C-reactive protein (CRP) was 6 mg/L, neither being significant.

Electrocardiography and postero-anterior chest radiography were normal. Transthoracic echocardiogram revealed an intra-cardiac mass in the right ventricle arising from the inter-ventricular septum (Figure 2) without any pedicular structure or valvular involvement. Transoesophageal echocardiogram confirmed the presence of the mass but excluded any shunting (Figure 3). As non-infectious endocarditis was considered, she was evaluated in more detail. OPEN IN VIEWER

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Figure 3.

Transoesophageal echocardiogram confirmed right ventricular mass.

Blood cultures appeared sterile. Urine routine examination revealed no red cells or protein. Rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP), anti-nuclear antibody (ANA) and anti-double stranded deoxyribonucleic acid (anti-dsDNA) were positive but anti-ribonucleoprotein particles (anti-RNP) and anti-neutrophil cytoplasmic antibodies (ANCAs) were negative (Table 1). The fasting blood glucose, lipid profile and serum creatinine were normal. The venereal disease research laboratory (VDRL) test was non-reactive. Anti-phospholipid antibody (aPA, IgM and IgG) appeared negative. Serum homocysteine, protein C and protein S levels were normal, as were prothrombin time and activated partial thromboplastin time. A Doppler study of neck vessels was normal.

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Table 1.

Relevant test reports of the patient with rhupus.

Laboratory reports	During diagnosis of RA	During diagnosis of rhupus	Reference values
ESR	110	30	<20 mm/1st h
CRP	38.3	6	<6 mg/L
RF	104.1	53.9	<21 IU/mL
Anti-CCP	–	56	>25 IU/mL
ANA	–	59.5	>10 U/mL
Anti-ds DNA	–	120.5	>75 U/mL

Thus, a diagnosis of rhupus complicated by LSE that had provoked a previous cerebral infarction with left sided hemi-paresis was made. Treatment included aspirin, hydroxychloroquine and atorvastatin; the patient was regularly followed up.

Discussion

Rhupus is an uncommon clinical condition; some authors consider it as a subset of systemic lupus erythematosus (SLE) while others consider it as an overlap of RA and SLE. Up to 20% of patients with RA may have positive ANA, 17% of SLE patients may have positive RF but only 1.3–2% fulfil the criteria for rhupus.^3,4 In most cases, RA precedes the manifestation of SLE by several years, but not always, and simultaneous onset of both RA and SLE may occur; organ involvement in rhupus is less common and less severe than SLE.^3,4

Central nervous system (CNS) involvement in rhupus may occur in 7% cases and includes venous sinus thrombosis, CNS vasculitis, thromboembolic stroke and cerebritis.^2,4 Thrombosis and emboli are usually associated with positive aPA. Embolic events may result from Libman-Sacks vegetations. ²

Absence of fever and stigmata of infective endocarditis, negative blood cultures, underlying rhupus and the echocardiographic characteristics of a cardiac mass suggested LSE in our case. The exact cause for cerebral infarction in our patient was not determined; this may be result of thrombosis, vasculitis or cardiac embolisation.

Rheumatological diseases evolve over time and every new feature should be taken into account during evaluation and follow-up, as management and prognosis vary with each different diagnosis.^3,4 Every patient with connective tissue disease merits cardiac evaluation including echocardiography ⁵ which may unveil LSE. Measures may then be taken to prevent life-threatening systemic or pulmonary embolism.