Dysfunctional hemostasis in patients under extracorporeal life support. A rapid diagnostic approach with therapeutical guidance intentions

ABSTRACT

Background: Short-term cardiopulmonary extracorporeal life supports (ECLS) are invasive devices whose use has increased exponentially during the COVID-19 pandemic. Major bleeding is a main cause of morbi-mortality in ECLS patients and acquired von Willebrand disease (aVWD) could justify this complication. Aim(s) We aim at investigating the primary hemostasis alterations profile in ECLS patients, and to propose a potential treatment if bleeding. Method(s) Patients in ECLS at our center since June 2021 were included (n = 25). Primary hemostasis was evaluated by Von Willebrand Factor antigen (VWFAg) and activity (VWFGPIbM) measurement (immunoturbidimetry), VWF multimeric analysis (agarose-gels and immunoblotting), platelet function analysis (PFA-200), and platelet activation (CD62P and CD63 expression by flow cytometry). Studies were performed 24 h after implant, each 7 days, and in the first week after ECLS extraction. T-TAS was used for hemostasis analysis in samples from bleeding patients, before and after in vitro addition of purified VWF. This study was approved by the Hospital Clinic's Ethics Committee (HCB/2021/0200). Result(s) After 24 h of ECLS implant, increased VWFAg levels and prolonged PFA occlusion times. In 60% of patients, altered VWFGPIbM/VWFAg ratio ( < 0.7) and loss of VWF high molecular weight multimers (HMWM) were observed. CD62P expression was slightly higher in ECLS patients platelets than in controls (MFI+/-SD of 4.34 +/- 2.2 vs. 3.27 +/- 0.6, respectively;p = 0.3). Early after ECLS extraction, there was normalization of the VWF multimeric profile and PFA values. Interestingly, in samples from bleeding patients, addition of purified VWF reduced significantly the T-TAS occlusion times (776 s+/-207 s vs. 1161 s+/-251 s, Mean+/-SD, post vs. pre, respectively;p = 0.033). Conclusion(s) ECLS caused primary hemostasis alterations, leading to aVWD and platelet activation, solved early after support removal. Hemostatic efficiency in ECLS bleeding patients, with lack of HMWM, was corrected in vitro by providing functional purified VWF. (Figure Presented).