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We prospectively evaluated the diagnostic accuracy of a new rapid assay (STic Expert HIT) alone or in combination with a clinical score in 90 HIT-suspected patients. The 4Ts score was calculated, and ELISA and serotonin-release assay (SRA) were performed; the average time taken for test results were 2 and 5 days for ELISA and SRA, respectively. The STic test was performed in our laboratory as an evaluation exercise and the result was available in 1 hour, but results were not communicated to the clinicians so as to not influence management. Diagnostic performance of STic test was assessed, alone and in combination with 4Ts score. HIT was diagnosed in 19 patients. The sensitivity, specificity, and positive and negative predictive values for the STic test alone were 95%, 92%, 75%, and 98%, respectively, with an accuracy of 92%. The likelihood ratio for positive and negative results with the STic test was 11.2 and 0.06. The combination of the 4Ts score and the STic test results had a negative predictive value of 100% and a negative likelihood ratio of 0. The favorable performance of the STic test may allow for the rapid exclusion of HIT in combination with a low to intermediate pretest clinical probability. During the subsequent year, using the STic test in real time to rapidly exclude the diagnosis, we observed a 50% reduction in danaparoid administration in HIT-suspected patients.

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PURPOSE OF REVIEW: The management of atrial fibrillation has seen marked changes in recent years. This is the result of better knowledge of the pathophysiology and risks factors for atrial fibrillation, better stratification for thromboembolic and bleeding risks, changing practices in anticoagulation management, and the development of new antiarrhythmic drugs. This article focuses on these new issues, with particular attention to their relevance in the perioperative period. RECENT FINDINGS: Improved understanding of the interaction between predisposing factors and the pathophysiological mechanisms of atrial fibrillation is changing management strategies. Preoperative identification of patients at risk for postoperative atrial fibrillation (POAF) is important so that measures such as ß-blockade may be introduced to prevent its occurrence. When POAF does occur, cardioversion is preferred in unstable patients and amiodarone is the most commonly used drug. Owing to the transient nature of POAF and excessive bleeding risk immediately postsurgery, anticoagulation should be used with caution in these patients. The perioperative management of patients on chronic oral anticoagulants is guided by weighing the risk of thromboembolic complications against the risk surgical bleeding. Risk stratification scoring systems and published guidelines facilitate decision-making. New oral anticoagulants offer potentially improved safety profiles over traditional agents; however, their optimal management in the perioperative period remains unknown. SUMMARY: Better knowledge of the pathophysiology of atrial fibrillation and improved awareness of the risks associated with this frequent arrhythmia are continuing to improve the management of patients with chronic atrial fibrillation and new-onset atrial fibrillation in the perioperative period. As with most complex disease processes, treatment decisions must be individualized for each patient and clinical context.

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OBJECTIVES: To assess the characteristics and prognosis of patients in whom heparin-induced thrombocytopenia (HIT) was confirmed (HIT+) among suspected HIT patients after having cardiac surgery and to assess the accuracy of two HIT scoring systems. DESIGN: An observational prospective study. SETTING: A cardiac surgery unit of a tertiary center from November 2005 to September 2007. PARTICIPANTS: Of the 1,722 patients who underwent cardiac surgery, 63 were suspected of HIT based on a platelet count <100 × 10(9)/L, a decrease in platelet count of >30%, or the occurrence of a thrombotic event. INTERVENTION: The HIT criteria were as follows: (1) the absence of another cause of thrombocytopenia, (2) positive antiplatelet factor 4 (PF4) antibodies (>0.5 optical density [OD]/mn) on enzyme-linked immunoabsorbent assay, and (3) recovery in platelet count after the discontinuation of heparin and substitution by danaparoid sodium. MEASUREMENTS AND MAIN RESULTS: HIT was confirmed in 24 patients (1.4% [0.8%-1.9%]); 23 belonged to the 984 treated by intravenous unfractionated heparin (IVUH) (2.3% IQ [1.4%-3.3%]) and 1 to the 738 treated by low-molecularweight heparin (0.14% [0.13%-0.4%]) (OD = 17.6; 95% confidence interval, 2.4-131; p < 0.0001). In the HIT+ patients compared with the unconfirmed HIT patients, thrombocytopenia occurred 7 (range, 6-9) days after surgery versus 3 (range, 3-5) days (p < 0.0001), and kinetics of platelet count showed a biphasic pattern. Six HIT+ patients (25% [7.7-42.3]) presented with an arterial thromboembolic event. Diagnosis performances of HIT scoring systems were low. CONCLUSIONS: Confirmed HIT occurred predominantly in patients treated with IVUH. The timing of thrombocytopenia and the variation pattern of the postoperative platelet count are key factors in diagnosing HIT. The overall incidence of intracardiac thrombotic events was noted to be high.

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The superiority of the left internal mammary artery (LIMA) graft over autogenous saphenous vein as a bypass conduit in coronary artery bypass surgery has been well established. Early and late patency rates of bilateral internal mammary artery (BIMA) grafts exceed those of vein grafts, and patients who receive BIMA have improved long-term survival rates and more freedom from reoperations and other cardiac events. But because of other concerns, particularly the question of increased risk of postoperative bleeding, controversy still surrounds the perioperative period. In the present study we sought to determine whether BIMA grafting was an independent risk factor of postoperative bleeding and of blood product use in patients undergoing primary elective coronary artery revascularization. For this purpose, 33 consecutive patients scheduled for BIMA grafting were matched with 66 patients operated on by single LIMA grafting. Patients in the LIMA group had significantly less postoperative mediastinal drainage than those in the BIMA group (median: 722 vs 920 mL, P = 0.0001). Fifty-six patients received blood products (56% vs 51% in LIMA and BIMA groups, respectively; P = 0.67). In multivariate analysis, BIMA and operative duration were independent predictors of increased postoperative drainage. Nevertheless, in logistic regression, BIMA was not significantly associated with blood product use, unlike precardiopulmonary bypass hematocrit and duration of surgery (OR and 95% CI: 0.89 [0.80-0.96] P = 0.01; 1.009 [1.001-1.019] P = 0.04, for an increase of 1% in hematocrit and 1 min in duration of surgery, respectively). In conclusion, these data support the idea that BIMA graft slightly increases postoperative drainage but not transfusion requirement.

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OBJECTIVE: The purpose of the present study was to evaluate the prognostic implications of perioperative B-type natriuretic peptide (BNP) and cardiac troponin I concentrations in patients undergoing cardiopulmonary bypass for cardiac surgery. DESIGN: Prospective observational study. SETTING: Biochemistry laboratory and surgical care unit in a university hospital. PATIENTS: A total of 92 consecutive patients undergoing elective coronary artery (43 patients) or valve surgery (49 patients). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: BNP and cardiac troponin I concentrations were measured before surgery (day 0), and at day 1 after surgery. Postoperative cardiac dysfunction was defined as low cardiac output or hemodynamic instability requiring inotropic support for >24 hrs or congestive heart failure until day 5. One-year survival was also evaluated. Univariate and multivariate analyses were performed. An important BNP secretion was systematically observed after cardiac surgery. Independent predictors of cardiac dysfunction were preoperative New York Health Association class and BNP and cardiac troponin I concentrations measured at day 1. Patients with an elevation of both markers have a 12-fold increased risk of postoperative heart failure. The use of both markers in combination predicted better postoperative heart failure than each one separately. Age, low preoperative left ventricular ejection fraction, and elevated BNP at day 1 (>352 pg/mL) were associated with an increased mortality rate at 1 yr. In multivariate analysis, only left ventricular ejection fraction was significantly associated with 1-yr survival. CONCLUSIONS: Postoperative plasma BNP and cardiac troponin I levels are independent predictors of postoperative cardiac dysfunction after cardiac surgery. Simultaneous measurement of BNP and cardiac troponin I improve the risk assessment of postoperative cardiac dysfunction. However, the association between BNP levels and 1-yr outcome was no longer significant after adjustment on left ventricular ejection fraction.

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OBJECTIVE: Platelet adhesion to the subendothelial tissue via the collagen receptor alpha2beta1 is a crucial event in vascular biology. Although evidence has been provided that the number of platelets alpha2beta1 copies is genetically determined, the molecular change primary responsible has not been yet elucidated. The aim of our present study was to investigate the effect of combined polymorphisms within both regulatory (-52C/T and -92C/G) and coding regions (807C/T and 1648A/G) of the alpha2 subunit gene on human platelets alpha2beta1 receptor density and/or susceptibility to coronary artery disease (CAD). METHODS AND RESULTS: Among 254 cardiac surgery patients, no evidence was found for an association between the alpha2 subunit gene polymorphisms and CAD. In contrast, in a subgroup of 113 patients, we observed a significant association between all polymorphisms except -52C/T and alpha2beta1 receptor level. Furthermore, when 3 groups of patients were defined according to the tertiles of platelets alpha2beta1 copies, the -92C/807T haplotype was more frequent in the group of patients with high alpha2beta1 receptor level. CONCLUSIONS: These results suggest that an individual effect of each polymorphism located either in the coding or promoter sequence of the alpha2 gene may act in combination to modulate variations in platelets alpha2beta1 receptor density.

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