Etiology and management of chronic valve disease in antiphospholipid antibody syndrome and systemic lupus erythematosus

Arterial thrombosis in antiphospholipid syndrome (APS): Clinical approach and treatment. A systematic review

Thrombotic Antiphospholipid Syndrome (APS) is a condition affecting young individuals in whom a thromboembolic event occurs in the presence of circulating antiphospholipid antibodies (aPL). An extensive body of literature has covered the most common clinical presentation of the syndrome, venous thromboembolism. Arterial thrombosis in APS, a lesser clinical expression, is less studied. This review will concentrate on the body of literature concerning pathogenesis, clinical presentation and management of arterial thrombosis in APS.

Cardiac involvement in the antiphospholipid syndrome

Antiphospholipid syndrome (APS) is a systemic autoimmune disease, associated with a hypercoagulable state and fetal loss and with other clinical manifestations including cardiac involvement. Cardiac manifestations of APS are valve abnormalities (valve thickening and vegetations), occlusive arterial disease (atherosclerosis and myocardial infarction), intracardiac emboli, ventricular dysfunction, and pulmonary hypertension. Antiphospholipid antibodies (aPLs) may have a role in the accelerated atherosclerotic arterial disease observed in APS, related to their ability to induce endothelial activation. aPLs have been incriminated in the pathogenesis of heart valve lesions in APS patients. Markers of endothelial cell activation are up-regulated with prominent deposition of aPL in heart valves, suggesting aPL deposition initiates an inflammatory process that recruits complement leading to the valve lesion. Autoantibody-mediated endothelial cell activation probably plays a role in sustaining a proadhesive, proinflammatory, and procoagulant phenotype. The heterogeneity of APS clinical manifestations is likely linked to the varied effects that aPL can induce on endothelial cells and to the different functions that endothelial cells display depending on the anatomic localization.

Current treatment of antiphospholipid syndrome: lights and shadows

For patients with antiphospholipid syndrome (APS), the consensus is to treat those who develop thrombosis with long-term oral anticoagulation therapy and to prevent obstetric manifestations by use of aspirin and heparin. These recommendations are based on data from randomized controlled trials and observational studies. Despite this body of knowledge, areas of uncertainty regarding the management of APS exist where evidence is scarce or nonexistent. In other words, for a subset of patients the course of management is unclear. Some examples are patients with 'seronegative' APS, those who do not fulfil the formal (clinical or serological) classification criteria for definite APS, and those with recurrent thrombotic events despite optimal anticoagulation. Other challenges include the treatment of clinical manifestations not included in the classification criteria, such as haematologic manifestations (thrombocytopenia and haemolytic anaemia), neurologic manifestations (chorea, myelitis and multiple sclerosis-like lesions), and nephropathy and heart valve disease associated with antiphospholipid antibodies (aPL), as well as the possible withdrawal of anticoagulation treatment in selected cases of thrombotic APS in which assays for aPL become persistently negative. This Review focuses on the current recommendations for thrombotic and obstetric manifestations of APS, as well as the management of difficult cases. Some aspects of treatment, such as secondary prophylaxis of venous thrombosis, are based on strong evidence--the 'lights' of APS treatment. Conversely, other areas, such as the treatment of non-criteria manifestations of APS, are based only on expert consensus or common sense and remain the 'shadows' of APS therapy.

Pulmonary arterial hypertension in systemic lupus erythematosus: current status and future direction

Pulmonary arterial hypertension (PAH) is commonly associated with connective tissue diseases (CTDs) including systemic sclerosis and systemic lupus erythematosus (SLE). The prevalence of PAH in SLE is estimated to be 0.5% to 17.5%. The pathophysiology of PAH involves multiple mechanisms from vasculitis and in-situ thrombosis to interstitial pulmonary fibrosis which increases pulmonary vascular resistance, potentially leading to right heart failure. Immune and inflammatory mechanisms may play a significant role in the pathogenesis or progression of PAH in patients with CTDs, establishing a role for anti-inflammatory and immunosuppressive therapies. The leading predictors of PAH in SLE are Raynaud phenomenon, anti-U1RNP antibody, and anticardiolipin antibody positivity. The first-line of diagnostic testing for patients with suspected SLE-associated PAH (SLE-aPAH) involves obtaining a Doppler echocardiogram. Once the diagnosis is confirmed by right heart catheterization, SLE-aPAH patients are generally treated with oxygen, anticoagulants, and vasodilators. Although the prognosis and therapeutic responsiveness of these patients have improved with the addition of intensive immunosuppressive therapies, these treatments are still largely unproven. Recent data put the one-year survival rate for SLE-aPAH patients at 94%. Pregnant women are most at risk of dying due to undiagnosed SLE-aPAH, and screening should be considered essential in this population.

Systemic lupus erythematosus and systemic autoimmune connective tissue disorders behind recurrent diastolic heart failure

Diastolic heart failure (DHF) remains unexplained in some patients with recurrent admissions after full investigation. A study was directed for screening SLE and systemic autoimmune connective tissue disorders in recurrent unexplained DHF patients admitted at a short-stay and intermediate care unit. It was found that systemic autoimmune conditions explained 11% from all of cases. Therapy also prevented new readmissions. Autoimmunity should be investigated in DHF.

Task Force on Catastrophic Antiphospholipid Syndrome (APS) and Non-criteria APS Manifestations (I): catastrophic APS, APS nephropathy and heart valve lesions

The objectives of the 'Task Force on Catastrophic Antiphospholipid Syndrome (APS) and Non-criteria APS Manifestations' were to assess the clinical utility of the international consensus statement on classification criteria and treatment guidelines for the catastrophic APS, to identify and grade the studies that analyse the relationship between the antiphospholipid antibodies and the non-criteria APS manifestations and to present the current evidence regarding the accuracy of these non-criteria APS manifestations for the detection of patients with APS. This article summarizes the studies analysed on the catastrophic APS, APS nephropathy and heart valve lesions, and presents the recommendations elaborated by the Task Force after this analysis.

Mitral valve surgery for mitral regurgitation caused by Libman-Sacks endocarditis: a report of four cases and a systematic review of the literature

Libman-Sacks endocarditis of the mitral valve was first described by Libman and Sacks in 1924. Currently, the sterile verrucous vegetative lesions seen in Libman-Sacks endocarditis are regarded as a cardiac manifestation of both systemic lupus erythematosus (SLE) and the antiphospholipid syndrome (APS). Although typically mild and asymptomatic, complications of Libman-Sacks endocarditis may include superimposed bacterial endocarditis, thromboembolic events, and severe valvular regurgitation and/or stenosis requiring surgery. In this study we report two cases of mitral valve repair and two cases of mitral valve replacement for mitral regurgitation (MR) caused by Libman-Sacks endocarditis. In addition, we provide a systematic review of the English literature on mitral valve surgery for MR caused by Libman-Sacks endocarditis. This report shows that mitral valve repair is feasible and effective in young patients with relatively stable SLE and/or APS and only localized mitral valve abnormalities caused by Libman-Sacks endocarditis. Both clinical and echocardiographic follow-up after repair show excellent mid- and long-term results.

Cardiac manifestations in the antiphospholipid syndrome

Experimental evidence reveals that aPL are not only markers of APS, but also may play a causative role in the development of vascular thrombosis and pregnancy morbidity. The pathogenic mechanisms of aPL seem to be heterogeneous, including endothelial cell activation, the direct inhibition of the activated protein C pathway, abnormalities in platelet function, and in complement activation. aPLs induce proadhesive, proinflammatory, and procoagulant molecules that provide a persuasive explanation for induction of thrombosis in APS. Cardiac manifestations in APS include valve abnormalities (valve thickening and vegetations), occlusive arterial disease (atherosclerosis and myocardial infarction), intracardiac emboli, ventricular dysfunction, and pulmonary hypertension. aPL may be associated with accelerated atherosclerosis in APS patients. Valve disease is the most important and most common cardiac manifestation of APS. The precise mechanism by which valves become deformed is not yet fully known.

Morphology of vascular, renal, and heart lesions in the antiphospholipid syndrome: relationship to pathogenesis

A growing body of evidence suggests that aPL are not only serological markers of the antiphospholipid syndrome (APS), but may also directly contribute to the development of thrombosis and other manifestations, including the APS vasculopathy. The latter has been documented in leptmeninges, lung, skin, myocardium, peripheral arteries, and kidney. Renal lesions, a common feature of primary antiphospholipid syndrome (PAPS), include occlusion of principal renal arteries or their main branches, TMA, cortical ischemia, and renal vein thrombosis. Within the cardiac manifestations associated with aPL, valvular involvement is the most common. Histologic findings in valve specimens are consistent with a noninflammatory lesion characterized by intravalvular capillary thrombosis, laminar or verrucous superficial thrombosis, vascular proliferation, fibrosis, and calcification. Even though there is general consensus that endothelial damage triggers the chain of events that results in valve thickening, fusion, rigidity, and ultimately functional abnormalities, we believe that more experimental work remains to be done on the initial valve insult in APS.

Valvular dysfunction in antiphospholipid syndrome: prevalence, clinical features, and treatment

Valvular abnormalities develop in 36% and 35% of patients with primary antiphospholipid syndrome (PAPS) and with systemic lupus erythematosus (SLE) respectively, and in 48% of patients with SLE and antiphospholipid antibodies (aPL). Valvulopathy includes leaflet thickening, vegetations, regurgitation, and stenosis. A literature survey shows that significant morbidity from valvular dysfunction, mostly mitral regurgitation leading to congestive heart failure, occurs in 4% and 6% of SLE and PAPS patients, respectively. The pathogenesis of valvulopathy may involve interaction of aPL with antigens on the valve surface, resulting in valvulitis. Current therapy includes symptomatic measures and valve replacement. A novel approach for symptomatic antiphospholipid syndrome (APS) related valvulopathy involves treatment with systemic corticosteroid. We describe four such patients and their dramatic clinical and hemodynamic response to treatment with prednisone when symptomatic measures failed.