Cost Analysis of Transfusion Therapy in Coronary Artery Surgery.

BACKGROUND: In patients undergoing coronary artery bypass grafting (CABG), wide variability in transfusion rate (7.8% to 92.8%) raises the question of the amount of unnecessary transfusions. The aim of the study was (1) to identify CABG patients at low risk of bleeding to whom transfusion treatment should be avoided and (2) to calculate the amount of possible cost savings that would be achieved by avoiding transfusion in low bleeding risk patients. METHODS: This retrospective observational study enrolled patients undergoing isolated elective CABG from January 2010 to January 2018. Patients were divided with respect to the presence of excessive bleeding and transfusion costs were compared between the two groups. Predictors for postoperative excessive bleeding were defined and multivariable logistic regression analysis and risk modeling were performed. The use of a model to predict patients at low risk of bleeding allowed for the estimation of transfusion cost savings assuming the patients who were found to be at low risk of bleeding should not be transfused. RESULTS: A total of 1,426 patients were enrolled in the analysis. Of those, 28.3% had excessive postoperative bleeding. The multivariate logistic regression analysis model was developed to identify/predict patients without excessive bleeding (receiver operating characteristic curve analysis, area under the curve 72.3%, p < 0.001). When applied to the existing database, the use of the developed model identifying patients at low risk of bleeding may result in a 39.1% reduction of transfusions. Specifically, cost savings would be 48.2% for packed red blood cells, 38.9% for fresh frozen plasma, 10.9% for platelets concentrate, and 17.9% for fibrinogen concentrate. CONCLUSION: The clinical and economic burdens associated with unnecessary transfusions are significant. Avoiding transfusion in CABG patients found to be at low risk of bleeding may result in significant reduction of transfusion rate and transfusion-associated costs.

Activated coagulation time vs. intrinsically activated modified rotational thromboelastometry in assessment of hemostatic disturbances and blood loss after protamine administration in elective cardiac surgery: analysis from the clinical trial (NCT01281397).

BACKGROUND: Excessive bleeding after cardiopulmonary bypass (CPB) is risk factor for adverse outcomes after elective cardiac surgery (ECS). Although many different point-of-care devices to diagnose hemostatic disturbances after CPB are available, the best test is still unclear. The study aim was to compare the accuracy of hemostatic disorder detection between two point-of-care devices. METHODS: We enrolled 148 patients (105 male and 43 female) undergoing ECS in a prospective observational study. Rotational thromboelastometry (TEM, with InTEM test), and Activated coagulation time (ACT) measurement were performed 15 min after protamine administration. The cohort group was divided into two subgroups according to occurrence of excessive postoperative bleeding. Endpoints were defined in two ways: as total amount of chest tube output (CTO) and blood product transfusion requirements. RESULTS: Total amount of CTO value of 1507,50 mL presented 75th percentile of distribution, thus cut-off value for bleeder category. InTEM parameters, but not ACT, correlated significantly with CTO. InTEM parameters with the strongest correlation to CTO were tested for accuracy in predicting excessive postoperative bleeding using ROC analysis. InTEM A 10 value of 38 mm, InTEM A 20 value of 49 mm and InTEM A 30 value of 51 mm delineated bleeding tendency. Patients with total amount of CTO exceeding 75th percentile were more frequently transfused with fresh frozen plasma (51.4% vs. 9.9%, p < 0.001), fibrinogen concentrate (21.6% vs. 2.7%, p = 0.001) and platelet concentrate (13.5% vs. 0.9%, p = 0.004). CONCLUSION: Our study showed that InTEM test, but not ACT is useful in prediction of bleeding tendency after protamine administration following weaning from CPB. InTEM test could be used as a first line test in screening of possible hemostatic disorder following protamine administration.

Bleeding risk assessment using whole blood impedance aggregometry and rotational thromboelastometry in patients following cardiac surgery.

Excessive bleeding after cardiopulmonary bypass (CPB) is risk factor for adverse outcomes after elective cardiac surgery (ECS). Differentiating between patients who bleed due to surgical issues and those whose excessive chest tube output (CTO) is due to coagulopathy, remains challenging. Bedside suitable tests to identify hemostatic disturbances and predict excessive bleeding are desirable. The study sought to evaluate prediction of excessive bleeding after ECS using two bedside suitable devices for platelet function and viscoelastic blood clot properties assessment. We enrolled 148 patients (105 male and 43 female) undergoing ECS in a prospective observational study. Patients were characterized as bleeders if their 24 h CTO exceeded the 75th percentile of distribution. Multiple electrode aggregometry (MEA, with ASPI, ADP and the TRAP test) and rotational thromboelastometry (TEM, with ExTEM, HepTEM and FibTEM test), were performed at three time points: preoperatively (T1), during CPB (T2), and after protamine administration (T3). The primary endpoint was CTO and the secondary endpoint was administration of blood products, 30-day and 1 year mortality. The best predictors of increased bleeding tendency were the tests performed after protamine administration (T3). At T3, patients characterized as bleeders had significantly lower MEA ASPI (median, 14 vs. 27 AUC, p = 0.004) and ADP test values (median, 22 vs. 41 AUC, p = 0.002) as well as TEM values expressed in maximum clot firmness after 30 min (MCF 30) for ExTEM (53 vs. 56 mm, p = 0.005), HepTEM (48 vs. 52 mm, p = 0.003) and FibTEM (8 vs. 11 mm, p < 0.001) test. 24 h CTO inversely correlated with both the MEA (ASPI test: r = -0.236, p = 0.004; ADP test: r = -0.299, p < 0.001), and TEM MCF 30 (ExTEM: r = -0.295, p < 0.001; HepTEM: -0.329, p < 0.001; FibTEM: -0.377, p < 0.001) test values. Our study showed that MEA and TEM are useful methods for prediction of excessive bleeding after ECS. In order to prevent excessive postoperative CTO, hemostatic interventions with timely and targeted blood component therapy according to MEA and TEM results should be considered.

Assessment of platelet function by whole blood impedance aggregometry in coronary artery bypass grafting patients on acetylsalicylic acid treatment may prompt a switch to dual antiplatelet therapy.

Residual platelet reactivity (RPR) following coronary artery bypass grafting (CABG) might be related to thrombotic complications and major ischemic cardiac events. The aim of this study was to evaluate the changes in platelet reactivity monitored pre- and postoperatively using multiple-electrode aggregometry (MEA) and to propose an alternative therapeutic approach in a subgroup of patients with postoperative RPR. Ninety-nine patients undergoing elective CABG were enrolled in the study, of whom 41 (41.4%) were diabetic. Preoperatively, all patients received 100 mg acetylsalicylic acid (ASA), with 47 of 99 (47.4%) patients receiving an additional 75 mg clopidogrel (CLO). The blood samples were drawn the day before surgery, and on the first and 4th postoperative day. Platelet count and fibrinogen level were documented, as well as type and daily dose of antiplatelet therapy (APT) received pre- and postoperatively. Multiple-electrode aggregometry using tests based on arachidonic acid (ASPI test) and adenosine diphosphate (ADP test) was performed on the day before and 4 days after surgery. Preoperatively, we detected 31 of 99 (31.3%) patients with RPR (ASPI > 30 AUC). Platelet count correlated with both the ASPI (P = 0.03) and ADP (0.002) tests. Fibrinogen correlated with ADP test values (P < 0.001) and was found to have a higher level in the diabetic subgroup (P = 0.01). In comparison with preoperative results, we detected higher values of ASPI test postoperatively (P = 0.04), with 46 of 99 (46.5%) patients having RPR despite a higher dose of 300 mg ASA being administered. Postoperatively, diabetic patients had higher ASPI test values (P = 0.01), and a higher proportion of patients with RPR compared with the nondiabetic subgroup (58.5 vs 38%, P = 0.04). The subgroup of patients with detected ASPI >30 AUC at the 4th postoperative day consequently received as a part of our clinical routine an additional 75 mg CLO per day, in terms of platelet inhibition optimization. Multiple-electrode aggregometry can recognize patients with RPR during both the pre- and post-CABG period. Postoperatively administered ASA (300 mg) did not sufficiently inhibit platelet aggregation in 46.5% of post-CABG patients. In this group of patients a switch to dual APT should be considered.

Bleeding risk assessment using multiple electrode aggregometry in patients following coronary artery bypass surgery.

Individual variability in the response to antiplatelet therapy (APT), frequently administered preoperatively, has been established by various platelet function assays and could reflect bleeding tendency after coronary artery bypass surgery (CABG). Our hypothesis is that multiple electrode whole-blood aggregometry (MEA) can identify patients at risk for excessive bleeding. We enrolled 211 patients (155 male and 56 female) undergoing isolated CABG in a prospective observational study. Patients were divided into four groups with respect to their preoperative APT management. MEA, using the ASPI and the ADP test, was performed prior to surgery. The primary endpoint was chest tube output (CTO) and the secondary endpoint was perioperative packed red blood cell concentrate (PRBC) administration. Patients were characterized as bleeders if their 24 h CTO exceeded the 75th percentile of distribution. 24 h CTO value of 11.33 ml/kg presented 75th percentile of distribution, thus cut-off value for "bleeder category". The proportion of patients characterized as bleeders was significantly different among the groups in regard to preoperative APT (p = 0.039). Significant differences in both ASPI (p < 0.001) and ADP (p = 0.038) tests were observed between different preoperative APT groups. Significant correlations between the ASPI test (r = -0.170, p = 0.014) and ADP test (r = -0.206, p = 0.003) with 24 h CTO were found. The receiver operating curve revealed an ASPI test value of <20 area under curve (AUC) units (AUC 0.603, p = 0.023) and an ADP test <73 AUC (AUC 0.611, p = 0.009) as a "bleeder" determinant. The proportion of patients transfused with PRBC did not significantly differ among the groups in regard to preoperative APT (p = 0.636). Comparison of the ASPI test values between patients with respect to PRBC administration revealed lower values in the ASPI test in a group of patients transfused with PRBC (mean, 27.88 vs. 40.32 AUC, p = 0.002). Our study showed that MEA is a useful method of predicting CABG patients with excessive postoperative bleeding.