Factors contributing to thrombocytopenia after cardiac surgery; towards defining coagulation-friendly cardiac surgery

IntroductionThe anticoagulation strategy and the cardiopulmonary bypass management represent two core elements of the intraoperative care of the cardiac surgery patient. The ideal approach remains an issue of debate, though data encourage the development of a coagulation friendly environment. Our aim was to investigate the effect of intraoperative management on postoperative thrombocytopenia in cardiac surgery patients.MethodsThis is a retrospective study set at a tertiary university hospital. Patients who underwent valve and complex cardiac surgery from January 2019 to December 2021 were included. All patients were managed with Minimally Invasive Extracorporeal Circulation. Platelet count, the anticoagulation technique, hemoglobin, transfusion and bleeding data were recorded perioperatively.ResultsA total of 65 patients met the inclusion criteria and were analysed. Postoperatively platelet count decreased from 208 (84) to 169 (63) (p < 0.001), while at 48 hours 7 patients had a platelet count <80 × 10⁹.l^-1. According to regression analysis, CPB duration and total heparin dose were independent predictors of platelet count whereas no significant correlation was found for protamine dose. After selecting for the anticoagulation technique, patients who received heparin concentration monitoring had significantly lower relative decline in platelet count at 48 hours (p = 0.04), received a higher total heparin dose (p = 0.03) but were given less protamine (p < 0.001). Overall, the frequency of transfusion was low and a trend toward less RBC transfusion was recorded when heparin-level concentration was used (p = 0.051).ConclusionsStrict heparin-level concentration monitoring combined with Minimally Invasive Extracorporeal circulation may have contributed to a coagulation-friendly cardiac surgery translating into a low incidence of thrombocytopenia and transfusions.