TRACKing or TRUSTing transfusion prediction:Validation of Red blood cell transfusion prediction models for low transfusion rate cardiac surgery and high transfusion rate post-cardiotomy veno-arterial extracorporeal life support

Abstract bodyPreoperative identification of patients at risk of red blood cell (RBC) transfusion is necessary to prevent adverse outcomes. Several models can determine this risk. Models like TRACK, TRUST and ACTA-PORT differ in complexity and performance. Some models outperform TRACK, but their complexity limits clinical application. In 2009, the TRACK model was developed with criteria for everyday practice, simplicity and easy clinical implementation. Advances in hemodilution management in Europe has reduced transfusion rates in adult cardiac surgery, necessitating re-evaluation of the TRACK model in low transfusion rate populations.MethodsThe TRACK model was validated using 4053 adult patients who underwent cardiac surgery between 2015 and 2022. Subsequently, the database was divided at random into a derivation and validation data set. Original coefficients of the TRACK model were updated in the derivation data set and validated in a validation data set on accuracy and discriminative ability. Model calibration and discriminative ability were assessed as measures of model performance. Further, the TRACK model will be validated and updated in the same way for predicting blood transfusion in post-cardiotomy ECLS patients.ResultsAll variables but age remained significant in the external validation of the TRACK model. The odds ratio of female sex on blood transfusion increased from 1.42 to 2.42 (95% CI, 1.94 – 3.02). The original TRACK model demonstrated an area under the curve (AUC) of 0.76 (95% CI, 0.74 – 0.78) while showing poor calibration indicating overoptimistic estimation of RBC transfusion risk (p &lt; 0.05). The updated TRACK model demonstrated a slightly higher AUC of 0.78 (95% CI,0.75 – 0.81) and showed good calibration over all risk strata (p = 0.19).ConclusionsRefining the TRACK coefficients improved preoperative at-risk identification. The updated TRACK model improves predicted accuracy and may help clinicians make better discissions, especially in low-transfusion adult cardiac surgery. This study demonstrates the feasibility of RBC transfusion prediction models for adult cardiac surgery. Our ongoing study is evaluating RBC transfusion prediction models for post-cardiotomy ECLS. These results will also be presented at the conference.<br/

Anticoagulation management during pulmonary endarterectomy with cardiopulmonary bypass and deep hypothermic circulatory arrest

INTRODUCTION: Pulmonary endarterectomy requires cardiopulmonary bypass and deep hypothermic circulatory arrest, which may prolong the activated clotting time. We investigated whether activated clotting time-guided anticoagulation under these circumstances suppresses hemostatic activation. METHODS: Individual heparin sensitivity was determined by the heparin dose-response test, and anticoagulation was monitored by the activated clotting time and heparin concentration. Perioperative hemostasis was evaluated by thromboelastometry, platelet aggregation, and several plasma coagulation markers. RESULTS: Eighteen patients were included in this study. During cooling, tube-based activated clotting time increased from 719 (95% confidence interval = 566-872 seconds) to 1,273 (95% confidence interval = 1,136-1,410 seconds; p 240 seconds. Platelet aggregation through activation of the P2Y12 (adenosine diphosphate test) and thrombin receptor (thrombin receptor activating peptide-6 test) decreased (both -33%) and PF4 levels almost doubled (from 48 (95% confidence interval = 42-53 ng/mL) to 77 (95% confidence interval = 71-82 ng/mL); p < 0.01) between weaning from cardiopulmonary bypass and 3 minutes after protamine administration. CONCLUSION: This study shows a wide variation in individual heparin sensitivity in patients undergoing pulmonary endarterectomy with deep hypothermic circulatory arrest. Although activated clotting time-guided anticoagulation management may underestimate the level of anticoagulation and consequently result in a less profound inhibition of hemostatic activation, this study lacked power to detect adverse outcomes

Goal-directed perfusion to reduce acute kidney injury: a randomized trial

This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/ which permits use, distribution and reproduction in any medium, provided the original work is properly cited. This author accepted manuscript is made available following 12 month embargo from date of publication (April 2018) in accordance with the publisher’s archiving policyObjective To determine whether a goal-directed perfusion (GDP) strategy aimed at maintaining oxygen delivery (DO2) at ≥280 mL·min−1·m−2 reduces the incidence of acute kidney injury (AKI). Methods This multicenter randomized trial enrolled a total of 350 patients undergoing cardiac surgery in 9 institutions. Patients were randomized to receive either GDP or conventional perfusion. A total of 326 patients completed the study and were analyzed. Patients in the treatment arm were treated with a GDP strategy during cardiopulmonary bypass (CPB) aimed to maintain DO2 at ≥280 mL·min−1·m−2. The perfusion strategy for patients in the control arm was factored on body surface area and temperature. The primary endpoint was the rate of AKI. Secondary endpoints were intensive care unit length of stay, major morbidity, red blood cell transfusions, and operative mortality. Results Acute Kidney Injury Network (AKIN) stage 1 was reduced in patients treated with GDP (relative risk [RR], 0.45; 95% confidence interval [CI], 0.25-0.83; P = .01). AKIN stage 2-3 did not differ between the 2 study arms (RR, 1.66; 95% CI, 0.46-6.0; P = .528). There were no significant differences in secondary outcomes. In a prespecified analysis of patients with a CPB time between 1 and 3 hours, the differences in favor of the treatment arm were more pronounced, with an RR for AKI of 0.49 (95% CI, 0.27-0.89; P = .017). Conclusions A GDP strategy is effective in reducing AKIN stage 1 AKI. Further studies are needed to define perfusion interventions that may reduce more severe levels of renal injury (AKIN stage 2 or 3).Parke received a research grant from Green Lane Research and Education Board for this study