Prophylactic antithrombotic therapy for patients with systemic lupus erythematosus with or without antiphospholipid antibodies: do the benefits outweigh the risks? A decision analysis.

BACKGROUND: A high incidence of both arterial and venous thromboembolic events has been reported in patients with systemic lupus erythematosus (SLE), but the risks and benefits of primary prophylactic antithrombotic therapy have not been assessed. We measured the clinical benefit of 3 antithrombotic regimens in patients with SLE without antiphospholipid antibodies, with anticardiolipin antibodies, or with lupus anticoagulant. METHODS: A Markov decision analysis was used to evaluate prophylactic aspirin therapy, prophylactic oral anticoagulant therapy, and observation. Input data were obtained by literature review. Clinical practice was simulated in a hypothetical cohort of patients with SLE who had not experienced any previous episode of arterial or venous thromboembolic events. For each strategy, we measured numbers of thromboembolic events prevented and major bleeding episodes induced, and quality-adjusted survival years. RESULTS: Prophylactic aspirin therapy was the preferred strategy in all settings, the number of prevented thrombotic events exceeding that of induced bleeding episodes. In the baseline analysis (40-year-old patients with SLE), the gain in quality-adjusted survival years achieved by prophylactic aspirin compared with observation ranged from 3 months in patients without antiphospholipid antibodies to 11 months in patients with anticardiolipin antibodies or lupus anticoagulant. Prophylactic oral anticoagulant therapy provided better results than prophylactic aspirin only in patients with lupus anticoagulant and an estimated bleeding risk of 1% per year or less. CONCLUSIONS: Prophylactic aspirin should be given to all patients with SLE to prevent both arterial and venous thrombotic manifestations, especially in patients with antiphospholipid antibodies. In selected patients with lupus anticoagulant and a low bleeding risk, prophylactic oral anticoagulant therapy may provide a higher utility.

Antibodies against phospholipids and beta 2-glycoprotein I increase the risk of recurrent venous thromboembolism in patients without systemic lupus erythematosus.

We studied the prognostic significance of antiphospholipid antibodies for recurrence of venous thromboembolism (VTE), in 71 patients admitted for acute VTE (deep-vein thrombosis or pulmonary embolism) in a single internal medicine unit. Lupus anticoagulant (LA), antibodies directed against beta 2-glycoprotein I (beta 2GPI) and antibodies against both beta 2GPI and a mixture of phospholipids (cardiolipin, phosphatidylserine and phosphatidic acid) (APAs) were measured. The patients were followed-up (mean 4.9 years) to determine the time to the next VTE. We found LA in nine patients, anti-beta 2GPI antibodies in seven patients and APAs in six patients. The cumulative risk of recurring VTE was higher in patients with beta 2GPI-binding antibodies (hazard ratio 12.6, 95% CI 1.5-104.9; p = 0.0029). The risk associated with APAs was 11.5 (95% CI 1.3-98.9; p = 0.0049) and that for LA was 3.7 (95% CI 0.9-15.6; p = 0.055). The risk of VTE recurring was higher both in patients with antibodies directed against beta 2GPI, and in patients with antibodies directed against beta 2GPI and a mixture of phospholipids, than in patients without these antibodies.

Phosphorus magnetic resonance spectroscopy: a noninvasive technique for the study of occlusive arterial leg disease and peripheral vasodilator therapy.

Using 31P nuclear magnetic resonance spectroscopy of the calf muscle, the authors studied patients with peripheral arterial occlusive disease. They studied PCr depletion and intracellular pH during aerobic exercise in patients and controls. The phosphocreatine (PCr) index ([PCr]/([PCr] + [Pi])) at rest was correlated with blood flow measured by plethysmography. During aerobic exercise a greater decrease in pH was obtained in patients (p < 0.03). They also studied the work necessary to reach a PCr index = 0.5 during ischemic exercise. This workload was lower in patients than in controls: 32.99 +/- 3.04 J vs 58.89 +/- 8.55 J, p < 0.05. After vasodilator therapy the workload was improved in patients: 32.99 +/- 3.04 J vs 38.85 +/- 3.54 J, p < 0.05. These results suggest that therapy resulted in improved tissue perfusion in patients.

Risk for venous thrombosis related to antiphospholipid antibodies in systemic lupus erythematosus--a meta-analysis.

OBJECTIVE: To describe the relative risk for venous thrombosis (VT) associated with antiphospholipid antibodies (aPL) in systemic lupus erythematosus (SLE). DESIGN: Systematic review and meta-analysis of 26 articles that examined the association between aPL and VT in SLE. SETTING: Mostly secondary and tertiary referral centres. PATIENTS: 2249 patients with SLE, 1120 tested for LA (lupus anticoagulant) and 1563 tested for aCL (anticardiolipin antibodies). MAIN OUTCOME MEASURES: A summary of study characteristics and a critical appraisal of study quality were done. Two statistical combinations of 18 primary studies that examined the association of VT and LA and of 14 studies that examined the association of VT and aCL were performed to estimate the risk for VT associated with aPL. RESULTS: The odds ratios of the risk of VT related to the LA summarized from 18 studies were 5.61 [95% CI; 3.80-8.27] overall, 6.32 [CI; 3.71-10.78] for deep venous thrombosis and pulmonary embolism, 11.6 [3.65-36.91] for recurrent venous thrombosis after the first event. The odds ratios of the risk of VT related to aCL summarized from 14 studies were 2.17 [95% CI; 1.51-3.11] overall, 2.50 [CI; 1.51-4.14] for deep venous thrombosis and pulmonary embolism, 3.91 [1.14-13.38] for recurrent venous thrombosis after the first event. CONCLUSIONS: Patients with SLE and LA are at approximately six times greater risk for VT than patients without LA, whereas patients with SLE and aCL are approximately two times greater risk for VT than patients without aCL. We have identified important methodologic limitations and differences in study characteristics. Other risk factors for VT have not been thoroughly evaluated in these studies. Further studies are needed that provide an accurate estimate of the absolute risk for aPL related VT.

Relationship of insulin resistance to protein-energy malnutrition in patients with alcoholic liver cirrhosis: effect of short-term nutritional support.

Protein-energy malnutrition (PEM) and insulin resistance (IR) are common features of alcoholic liver cirrhosis (ALC). In order to determine a relationship between them, nutritional status and glucose homeostasis were studied in 26 patients with ALC. Nutritional status was assessed through dietary, anthropometric, and biological parameters. An IR index (M/I) was obtained from the euglycemic insulin clamp technique. M/I was significantly correlated with accurate markers of PEM (albumin, transthyretin, and retinol-binding protein) but not with other markers of liver dysfunction. Nine patients were studied before and after nutritional support: M/I was significantly improved as were serum markers of PEM. Other markers of liver dysfunction were also significantly improved. These findings suggest that PEM could be responsible, in part, for IR in patients with ALC who are frequently malnourished. Moreover, nutritional support improved insulin sensitivity in these patients.

Meta-analysis of the risk of venous thrombosis in individuals with antiphospholipid antibodies without underlying autoimmune disease or previous thrombosis.

Patients with systemic lupus erythematosus (SLE) and antiphospholipid antibodies (aPL) are at a greater risk for venous thromboembolism (VTE) than SLE patients without these antibodies. For patients without SLE there is a controversy about the risk associated with these antibodies and about their prognostic significance. We reviewed the degree of evidence and describe the odds ratio for VTE associated with aPL, namely the lupus anticoagulant (LA) and anticardiolipin antibodies (aCL), in patients without SLE. The study was a meta-analysis of seven observational studies of risk for antiphospholipid associated venous thromboembolism (VTE), excluding SLE patients. The strategies to identify published research included a computerized literature search and the review of citations in primarily relevant articles for the period 1983 to 1997. A summary of study characteristics and a critical appraisal of study quality were done. Summary odds ratios were obtained conducted using a random and a fixed effects-model. The overall odds ratio for aCL associated VTE obtained by fixed-effects model was 1.56 (95% CI, 1.10-2.24) and 1.64 (95% CI, 0.93-2.89) by random-effects model. The heterogeneity of these results appeared to be due in part to the detection limit of the aCL assay: the odds ratio was 3.21 (95% CI, 1.11-9.28) with both models when high titres only were considered. The overall odds ratio for LA associated VTE was 11.1 (95% CI, 3.81-32.3). In conclusion meta-analysis of the risk for antiphospholipid associated thrombosis demonstrated a higher risk in patients with the LA than in other patients. This risk was also higher than in patients with aCL even when high titres only were considered.