Outcomes of patients with antiphospholipid syndrome after pulmonary endarterectomy.

OBJECTIVES: Antiphospholipid syndrome (APS) is a risk factor for chronic thromboembolic pulmonary hypertension, for which the treatment of choice is pulmonary endarterectomy. The increased risk of postoperative thrombotic complications in patients with APS may complicate the perioperative management. The primary objective of this study was to investigate the impact of APS on mortality and morbidity rates after pulmonary endarterectomy. The secondary objective was to describe platelet count changes after pulmonary endarterectomy in patients with APS. METHODS: Data were collected prospectively for consecutive patients with APS who underwent pulmonary endarterectomy over a 5-year period [2007-2011] and for consecutive patients without APS who underwent pulmonary endarterectomy at the same centre during 2008-2011 [controls]. Major complications and daily platelet counts were collected. Haemodynamic parameters obtained by right heart catheterisation were recorded preoperatively and on the day after surgery. RESULTS: We identified 17 patients with APS [3.6% of all pulmonary endarterectomies] and 190 controls. Early haemodynamic results after pulmonary endarterectomy were similar in the two groups, with a greater than 35% decrease in pulmonary vascular resistance. Significantly higher proportions of patients with APS than of controls experienced stroke [11.8 vs 1.0%, P= 0.03] and delirium [47 vs 20%; P = 0.02]. Compared with the controls, the patients with APS had significantly lower platelet counts and had a higher occurrence rate of platelet counts of ≤ 50 g/l (71 vs 4%; P < 0.0001). Intensive care unit (ICU) mortality was not significantly different between the two groups [0/17 vs 7/190 (3.7%), P = 0.49]. CONCLUSIONS: Neurological complications and severe thrombocytopenia were more common after pulmonary endarterectomy in patients with than without APS. Haemodynamic results and ICU mortality rate were similar in the two groups.

Continuous or discontinuous tranexamic acid effectively inhibits fibrinolysis in children undergoing cardiac surgery with cardiopulmonary bypass.

Tranexamic acid is given continuously or discontinuously as an anti-fibrinolytic therapy during cardiac surgery, but the effects on fibrinolysis parameters remain poorly investigated. We sought to assess the effects of continuous and discontinuous tranexamic acid on fibrinolysis parameters in children undergoing cardiac surgery with cardiopulmonary bypass (CPB). Children requiring cardiac surgery or repeat surgery by sternotomy with CPB for congenital heart disease were randomized to receive either continuous or discontinuous tranexamic acid. Blood tranexamic acid, D-dimers, tissue plasminogen activator (tPA), tPA-plasminogen activator inhibitor 1 (tPA-PAI1) complexes, fibrinogen and fibrin monomers were measured and compared to values obtained from children who did not receive tranexamic acid. Tranexamic acid inhibited the CPB-induced increase in D-dimers, with a similar potency between continuous and discontinuous regimens. Time courses for tPA, fibrin monomers, and fibrinogen were also similar for both regimen, and there was a significant difference in tPA-PAI1 complex concentrations at the end of surgery, which may be related to a significantly higher tranexamic acid concentration. Continuous and discontinuous regimen are suitable for an effective inhibition of fibrinolysis in children undergoing cardiac surgery with CPB, but the continuous regimen was previously shown to be more effective to maintain stable tranexamic acid concentrations.

Clinical and biologic features of patients suspected or confirmed to have heparin-induced thrombocytopenia in a cardiothoracic surgical ICU.

BACKGROUND: The diagnosis of heparin-induced thrombocytopenia (HIT) is problematic in the surgical ICU, as there are multiple potential explanations for thrombocytopenia. We conducted a study to assess the incidence, clinical presentation, and outcome of HIT in a cardiothoracic surgical ICU. METHODS: From January 2005 to December 2010, all patients with suspicion of HIT were prospectively identified, and data were collected retrospectively. Detection of anti-PF4/heparin antibodies and functional assays were systematically performed. RESULTS: During the study period, 5,949 patients were admitted to the ICU (2,751 after cardiac surgery and 3,198 after thoracic surgery), of whom 101 were suspected to have HIT(1.7% [95% CI, 1.4%-2.0%]). Suspicion of HIT occurred at a median of 5 (4-9) days after ICU admission. Diagnosis was confirmed in 28 of 5,949 patients (0.47% [95% CI, 0.33%-0.68%]).Thrombosis was detected in 14 patients with HIT (50%) and in 12 patients without HIT (16%)( P 5 .0006). After receiver operating characteristic analysis (area under curve 5 0.78 0.06),a 4Ts score ≥ 5 had a sensitivity of 86% and a specificity of 70%. Course of platelet count was similar between the two groups. Six patients (21%) with HIT and 20 (27%) without died( P 5 .77). CONCLUSIONS: Even with a prospective platelet monitoring protocol, suspicion for HIT arose in <2% of patients in a cardiothoracic ICU. Most were found to have other causes of thrombocytopenia,with HIT confirmed in 28 of 101 suspected cases (0.47% of all patients in the ICU). The 4Ts score may have value by identifying patients who should have laboratory testing performed.The mortality of patients with HIT was not different from other very ill thrombocytopenic patients in the ICU.

Predictive factors for thrombosis and major bleeding in an observational study in 181 patients with heparin-induced thrombocytopenia treated with lepirudin.

The antithrombotic efficacy of lepirudin in patients with heparin-induced thrombocytopenia (HIT) is compromised by an increased risk for bleeding. A retrospective observational analysis in 181 patients (median age, 67 years) with confirmed HIT treated in routine practice with lepirudin was performed to identify predictive factors for thrombotic and bleeding complications. Lepirudin was administered at a mean (+/- SD) dose of 0.06 +/- 0.04 mg/kg/h (compared with a recommended initial dose of 0.15 mg/kg/h). Mean activated partial thromboplastin time was greater than 1.5 times baseline value in 99.4% of patients. Median treatment duration was 7.7 days. Until discharge from the hospital, 13.8% and 20.4% of patients experienced a thrombotic or a major bleeding event, respectively. On multivariate analysis, mean lepirudin dose was not a significant predictive factor for thrombosis. In contrast, mean lepirudin dose greater than 0.07 mg/kg/h, long duration of lepirudin treatment, and moderate to severe renal impairment were significant positive factors for major bleeding. Overall, these results suggest that the recommended dose of lepirudin in patients with HIT is too high; the use of reduced doses may be safer with regard to bleeding risk and does not compromise antithrombotic efficacy.