Efficacy of autologous plateletpheresis in adult aortic surgery: study protocol for a randomised controlled trial.

INTRODUCTION: Perioperative coagulopathy is common in patients undergoing aortic surgery, increasing the risk of excessive blood loss and subsequent allogeneic transfusion. Blood conservation has become a vital part of cardiovascular surgery, but measures to protect platelets from destruction by cardiopulmonary bypass (CPB) are still lacking. Autologous platelet concentrate (APC) may have potential benefits for intraoperative blood preservation, but its efficacy has not been studied extensively. This study aims to evaluate the efficacy of APC as a blood conservation technique to reduce blood transfusion in adult aortic surgery. METHODS AND ANALYSIS: This is a prospective, single-centre, single-blind randomised controlled trial. A total of 344 adult patients undergoing aortic surgery with CPB will be enrolled and randomised to either the APC group or the control group with a 1:1 randomisation ratio. Patients in the APC group will receive autologous plateletpheresis before heparinisation, while those in the control group will not. The primary outcome is the perioperative packed red blood cell (pRBC) transfusion rate. Secondary endpoints include the volume of perioperative pRBC transfusion; drainage volume within 72 hours post-surgery; postoperative coagulation and platelet function; and the incidence of adverse events. Data will be analysed according to the intention-to-treat principle. ETHICS AND DISSEMINATION: This study was approved by the institutional review board of Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College (no. 2022-1806). All procedures included in this study will be performed in adherence to the Helsinki Declaration. The results of the trial will be published in an international peer-reviewed journal. TRIAL REGISTRATION NUMBER: Chinese Clinical Trial Register (ChiCTR2200065834).

Association of Adenosine Diphosphate-Induced Platelet Maximum Amplitude With Postoperative Bleeding and Blood Transfusions in Patients Undergoing Coronary Artery Bypass Grafting.

OBJECTIVES: To investigate the association of adenosine diphosphate (ADP)-induced platelet maximum amplitude (MAADP) with postoperative bleeding and blood product transfusions in patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). DESIGN: This single-center observational study recruited 200 patients who underwent elective, first-time, isolated CABG with CPB. A rapid thromboelastography with platelet mapping test was conducted for all patients before the surgery. Patients were categorized by the preoperative MAADP into ≤50 mm (MAADP ≤50 group [n = 87]) and MAADP >50 mm (MAADP >50 group [n = 113]). The primary outcome was postoperative bleeding at 6 and 24 hours as measured by chest tube drainage volume. The perioperative blood product transfusions, postoperative complications, postoperative time course, and in-hospital mortality also were evaluated. SETTING: University hospital. PARTICIPANTS: Adult patients scheduled to undergo isolated primary CABG with CPB. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The study included 200 patients who underwent CABG with CPB. MAADP was >50 mm in 113 (56.5%) patients (MAADP >50 group). Compared with the MAADP >50 group, the postoperative chest tube drainage volume at 6 and 24 hours was significantly greater in the patients with MAADP ≤50 mm (476.90 ± 156.36 mL v 403.36 ± 133.24 mL; p < 0.001 and 935.86 ± 318.43 mL v 667.21 ± 222.75 mL; p < 0.001, respectively). The consumption of blood products in patients with MAADP ≤50 mm was significantly more than those with MAADP >50 mm. The durations of intensive care unit stay and length of postoperative hospital stay were markedly longer in the MAADP ≤50 group than in the MAADP >50 group (p = 0.001 and p = 0.005; respectively). There were no significant differences in adverse outcomes between the 2 groups except for the postoperative atrial fibrillation, which occurred more in the MAADP ≤50 group than in the MAADP >50 group (8.05% v 1.77%; p = 0.043). MAADP (area under the receiver operating characteristic curve of 0.767; p < 0.001) was demonstrated to have significant ability to predict bleeding tendency, with a sensitivity of 76.2% and a specificity of 69.0%. CONCLUSIONS: Preoperative MAADP may play a potential role in the prediction of postoperative bleeding and allogeneic blood transfusions and guide clinicians in perioperative management of patients undergoing CABG with CPB.

Different dose regimes and administration methods of tranexamic acid in cardiac surgery: a meta-analysis of randomized trials.

BACKGROUND: The efficacy of tranexamic acid (TXA) to reduce perioperative blood loss and allogeneic blood transfusion in cardiac surgeries has been proved in previous studies, but its adverse effects especially seizure has always been a problem of concern. This meta-analysis aims to provide information on the optimal dosage and delivery method which is effective with the least adverse outcomes. METHODS: We searched Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE for all relevant articles published before 2018/12/31. Inclusion criteria were adult patients undergoing elective heart surgeries, and only randomized control trials comparing TXA with placebo were considered. Two authors independently assessed trial quality and extracted relevant data. RESULTS: We included 49 studies with 10,591 patients into analysis. TXA significantly reduced transfusion rate (RR 0.71, 95% CI 0.65 to 0.78, P<0.00001). The overall transfusion rate was 35%(1573/4477) for patients using TXA and 49%(2190/4408) for patients in the control group. Peri-operative blood loss (MD - 246.98 ml, 95% CI - 287.89 to - 206.06 ml, P<0.00001) and re-operation rate (RR 0.62, 95% CI 0.49 to 0.79, P<0.0001) were also reduced significantly. TXA usage did not increase risk of mortality, myocardial infarction, stroke, pulmonary embolism and renal dysfunction, but was associated with a significantly increase in seizure attack (RR 3.21, 95% CI 1.04 to 9.90, P = 0.04).The overall rate of seizure attack was 0.62%(21/3378) for patients using TXA and 0.15%(5/3406) for patients in the control group. In subgroup analysis, TXA was effective for both on-pump and off-pump surgeries. Topical application didn't reduce the need for transfusion requirement, while intravenous delivery no matter as bolus injection alone or bolus plus continuous infusion were effective. Intravenous high-dose TXA didn't further decrease transfusion rate compared with low-dose regimen, and increased the risk of seizure by 4.83 times. No patients in the low-dose group had seizure attack. CONCLUSIONS: TXA was effective in reducing transfusion requirement in all kinds of cardiac surgeries. Low-dose intravenous infusion was the most preferable delivery method which was as effective as high-dose regimen in reducing transfusion rate without increasing the risk of seizure.

Effects of tranexamic acid on short-term and long-term outcomes of on-pump coronary artery bypass grafting: Randomized trial and 7-year follow-up.

AIMS: Safety evaluations of tranexamic acid (TXA) remain sparse, especially with respect to its impact on long-term outcomes in patients undergoing on-pump coronary artery bypass grafting (CABG). We hypothesized that the effects of TXA on perioperative bleeding and allogeneic transfusion and its impact on long-term clinical outcomes of patients receiving on-pump CABG are superior to those in the control group. METHODS: In this prospective, randomized, placebo-controlled trial, 210 patients undergoing primary and isolated on-pump CABG were randomly assigned to receive TXA or a corresponding volume of saline solution. Randomly assigned patients were followed up at 1, 3, 5, and 7 years after hospital discharge. Finally, 163 patients fulfilled the 7-year follow-up. The primary outcome was allogeneic red blood cell (RBC) transfusion. Long-term mortality and morbidity were also evaluated. RESULTS: Compared with placebo, TXA reduced the allogeneic RBC requirement in terms of the volume transfused (4.20 ± 4.06 vs 6.25 ± 4.86 units; P < 0.01), ratio exposed (52.0% vs 71.6%; P < 0.01), and blood loss volume (879.0 ± 392.5 vs 1154.0 ± 582.8 mL; P < 0.01). Except for myocardial infarction, there were no significant differences in mortality or morbidity between the two groups during the 7-year follow-up. The TXA group had a lower rate of myocardial infarction than did the placebo group (0.0% vs 4.9% at 84 months; P = 0.03). CONCLUSIONS: Tranexamic acid significantly decreased postoperative bleeding and allogeneic transfusion in patients undergoing on-pump CABG. The 7-year follow-up suggested that the use of TXA was safe and might play a potential role in the prevention of long-term myocardial infarction.

[Establishment of normal reference values for thromboelastography on Chinese population in Beijing].

OBJECTIVE: To determine the normal values for thromboelastography (TEG) in Chinese healthy adult volunteers residing in Beijing for over three years and compare them with those of the manufacturer's. METHODS: A total of 137 healthy adult volunteers were enrolled from June 2010 to August 2010. The technique was standardized with citrated blood and kaolin activator. And a Haemoscope 5000 device was employed. The TEG parameters analyzed were R, K, α, maximal amplitude (MA), LY30 and coagulation index (CI). All volunteers underwent the tests of prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and plasma fibrinogen level with the same blood sample. RESULTS: The reference ranges of 95% for 137 volunteers were R: 3.8 - 8.4 min, K: 0.8 - 3.3 min, α-Angle: 46.2 - 76.2°, MA: 50.0 - 70.8 mm, LY30: -3.3% - 4.0% and CI: -3.8 - 2.9. Overall, 24.1% (33/137) of the volunteers had at least one abnormal parameter while 7.3% (10/137) would have been considered coagulopathy had the manufacturer's reference values been used, resulting in a test specificity of 76.0%. As compared with the western ethnicity (the manufacturer's reference values), Chinese healthy volunteers were associated with lower fibrinogen functions. There were significantly different in R, K, α-Angle, MA and CI between men and women groups (all P < 0.01). CONCLUSION: This study supports the manufacturer's recommendation that each institute should determine its own normal reference values.