Ann Thorac Surg 2009;88:669-671. doi:10.1016/j.athoracsur.2008.11.074
© 2009 The Society of Thoracic Surgeons
Case Reports
Aortic Valve Replacement for Libman-Sacks Endocarditis
Uday P. Dandekar, FRCS (CTh)*,
Richard Watkin, MRCP,
Navin Chandra, MRCP,
Kirkpatrick C. Santo, FRCS,
Sunil Bhudia, FRCS,
Michael Pitt, MRCP,
Stephen J. Rooney, FRCS (CTh)
Department of Cardiothoracic Surgery, Queen Elizabeth Hospital, Edgbaston, Birmingham, United Kingdom
Accepted for publication November 10, 2008.
* Address correspondence to Dr Dandekar, Department of Cardiothoracic Surgery, Queen Elizabeth Hospital, Edgbaston, Birmingham, B15 2TH, United Kingdom (Email: uday.dandekar{at}uhb.nhs.uk).
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Abstract
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Cardiac involvement is a recognized complication of systemic lupus erythematosus (SLE), which can involve most cardiac components, including pericardium, conduction system, myocardium, heart valves, and coronaries. Libman-Sacks (verrucous) endocarditis is the characteristic cardiac valvular manifestation. We report a patient with SLE who had severe aortic regurgitation caused by Libman-Sacks endocarditis. The patient underwent successful mechanical aortic valve replacement.
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Introduction
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Cardiac involvement in systemic lupus erythematosus (SLE) has been recognized since the early 20th century. SLE can involve most cardiac components, including the pericardium, conduction system, myocardium, heart valves, and coronaries [1]. Libman-Sacks (verrucous) endocarditis is the characteristic cardiac valvular manifestation. Libman and Sacks first published a description of these atypical, sterile, verrucous vegetations in 1924 [2]. A significant proportion of SLE patients with valvular involvement need surgical intervention, which carries a high morbidity and mortality due to multisystem involvement.
A 35-year-old woman presented 2 years earlier with a persistent occipital headache. Results of investigations, including computed tomography scan of the head and lumbar puncture, were reported as normal. An incidental early diastolic murmur was detected, and transthoracic echocardiography demonstrated mild aortic regurgitation with preserved left ventricular (LV) systolic function. Mild aortic valve leaflet thickening was noted. She was discharged and monitored for increased symptoms or worsening echocardiographic features.
She presented 18 months later with complaints of dyspnea (New York Heart Association functional class III). Echocardiography showed severe aortic regurgitation with thickened aortic valve cusps and a dilated ventricle (Fig 1). The level of C-reactive protein was less than 1 mg/dL, but the erythrocyte sedimentation rate was 113 mm/h. The result of double-stranded DNA serology was negative, but antinuclear antibodies were detected (1:100) with diminished serum C3 and C4.
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Fig 1. (Right) Explanted aortic valve has multiple verrucous vegetations on all its leaflets. (Left) Echocardiography shows thickened aortic valve leaflets.
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Because the patient had a previous episode of nephritic syndrome, a renal biopsy was performed. Renal histology confirmed lupus nephritis; on this basis and the presence of polyarthralgia, the diagnosis of SLE with valvular involvement was established. Despite treatment with systemic steroids and immunosuppression, the dyspnea worsened and right upper limb weakness developed because of multiple, small cerebral cortical infarcts, confirmed on magnetic resonance image. Coronary angiography was normal, and a right heart catheter showed normal pulmonary artery pressure. Results of blood cultures remained negative throughout. She was referred for an urgent aortic valve operation.
The patient underwent a successful aortic valve replacement using a mechanical 21-mm Carbomedics Top-Hat supraannular aortic prosthesis (Sulzer; Carbomedics, Austin, TX). Myocardial protection was with intermittent antegrade cold blood cardioplegia. The operation revealed fibrinous pericardial adhesions. The aortic valve showed multiple verrucous vegetations on all its leaflets (Fig 1). Histologic findings of the aortic valve were consistent with Libman-Sacks endocarditis (Fig 2). Photomicrographs showed sections of the heart valve with extensive deposition of fibrin and other blood elements. The features are of bland vegetation consistent with Libman-Sacks endocarditis. The patient had an uneventful postoperative recovery and was discharged home on the day 7.
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Fig 2. Photomicrograph shows section of heart valve with extensive deposition of fibrin and other blood elements. Features of bland vegetation are consistent with Libman-Sacks endocarditis. (Hematoxylin and eosin stain, x100.)
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Comment
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Cardiac involvement in SLE is common. All SLE patients will have involvement of the heart at some stage during their illness [3]. Cardiac manifestations may be numerous and can involve many components of the heart, including the pericardium, conduction system, myocardium, heart valves, and coronary arteries [1].
The characteristic cardiac valvular manifestation in SLE is Libman-Sacks (verrucous) endocarditis, and its reported incidence varies widely. The use of steroids in the management of SLE seems to have decreased its prevalence. A large autopsy series showed the prevalence of Libman-Sacks endocarditis in SLE patients was 59% before corticosteroids began being used and 35% after their use [4]. Echocardiographic findings are nonspecific, and a definitive diagnosis can only be made on pathologic examination of the affected valves.
The mitral valve is the most frequently affected, but multivalvular involvement often occurs. The vegetations may occur near the edge of the valve or on both its surfaces. Rarely, the atrial or ventricular endocardium or the chordae tendinea and papillary muscles may be involved.
The vegetations maybe flat and only visible microscopically or can be raised, rounded, or verrucous. They are usually less than 0.5 cm in diameter. Vegetations consist of fibrin and thrombus with minimal inflammatory infiltrate. The presence of antiphospholipid and anticardiolipin antibodies may have a role in the pathogenesis of Libman-Sacks endocarditis through the initiation of nonbacterial thrombotic endocarditis; however, they were not identified in our patient.
The prevalence of significant valve dysfunction in SLE varies. In one prospective controlled study of 74 patients with SLE followed up by echocardiography for 5 years, 18% had clinically important valvular dysfunction, and 8% required surgical intervention [5]. Although valvular involvement is common in SLE, infective endocarditis is uncommon.
Data on surgical outcomes for valvular operations in patients with SLE is limited to case reports and small case series. One review of 12 patients with SLE who underwent valve replacement noted a 25% mortality rate [6]. The immediate mortality rate was 20% in patients with antiphospholipid syndrome undergoing valve replacement [7]. The high surgical mortality rate in this cohort may be partly due to multisystem involvement in SLE. Most patients are taking systemic corticosteroids and significant numbers of patients have renal impairment or require dialysis. Most patients show extensive tissue destruction with significant tissue thickening and verrucous vegetations. Valve repair therefore is often not feasible, and valve replacement remains the only option.
Valvular involvement in SLE is hypothesized to be immunologically mediated, there is therefore a theoretic risk that bioprosthetic or homograft replacements may be exposed to a similar immune response resulting in further prosthetic valve failure. Homograft mitral valve replacement, however, was successful in a young dialysis-dependent patient. This was done to avoid lifelong anticoagulation [8]; however, the long-term outcome is not known.
Mechanical prosthesis maybe the best option in these patients. Significant numbers of patients require anticoagulation owing to their hypercoagulable state from the antiphospholipid syndrome and thus it would seem reasonable to implant a mechanical prosthesis. Mechanical valve replacement also minimizes the need for repeat operations in these high-risk patients.
We used a mechanical prosthesis in our patient because of her young age, she had completed her family, and to avoid the need for repeat operation in the future. Long-term anticoagulation is managed with warfarin to achieve a target international normalized ratio of 2.5.
The medical management of patients with SLE has significantly improved, and more patients can be expected to survive long enough for significant valvular disease to develop. Because no therapy exists to prevent valvular involvement or slow its progression, more patients are likely to need valve replacements in the future. Importantly, aortic regurgitation in young patients is never normal, and an underlying cause should always be excluded.
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Acknowledgments
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We thank Dr Shalini Chaudhri for her help with histopathology.
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References
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- Moder KG, Miller TD, Tazelaar HD. Cardiac involvement in systemic lupus erythematosus Mayo Clin Proc 1999;74:275-284.[Abstract/Free Full Text]
- Libman E, Sacks B. A hitherto undescribed form of valvular and mural endocarditis Arch Intern Med 1924;33:701-737.[Abstract/Free Full Text]
- Bridgen W, Baywaters GL, Lessof MH, Ross IP. The heart in systemic lupus erythematosus Br Heart J 1960;22:1-16.[Free Full Text]
- Doherty NE, Siegel RJ. Cardiovascular manifestations of systemic lupus erythematosus Am Heart J 1985;110:1257-1265.[Medline]
- Galve E, Candell-Riera J, Pigrau C, Permanyer-Miralda G, Garcia-Del-Castillo H, Soler-Soler J. Prevalence, morphologic types, and evolution of cardiac valvular disease in systemic lupus erythematosus N Engl J Med 1988;319:817-823.[Medline]
- Dajee H, Hurley EJ, Szarnicki RJ. Cardiac valve replacement in systemic lupus erythematosus: a review J Thorac Cardiovasc Surg 1983;85:718-726.[Abstract]
- Berkun Y, Elami A, Meir K, Mevorach D, Naparstek Y. Increased morbidity and mortality in patients with antiphospholipid syndrome undergoing valve replacement surgery J Thorac Cardiovasc Surg 2004;127:414-420.[Abstract/Free Full Text]
- Chauvaud SM, Kalangos A, Berrebi A, Gaer J, Acar C, Carpentier A. Systemic lupus erythematosus valvulitis: mitral valve replacement with a homograft Ann Thorac Surg 1995;60:1803-1805.[Abstract/Free Full Text]
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Abstract
Introduction
