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Introduction: The activity of direct oral anticoagulants (DOAC) is important in acute clinical situations. Recent studies have suggested a strong influence of DOAC on the diluted Russel's Viper Venom Time (dRVVT). Therefore, it may be a suitable screening parameter for antithrombotic plasma activity of different DOAC. This prospective study aims to evaluate the sensitivity and specificity of dRVVT to detect residual DOAC activity at recommended plasma level thresholds. Methods: A total of 80 patients were recruited, with 20 each treated with one of the four approved DOAC (apixaban, edoxaban, rivaroxaban or dabigatran), respectively. Blood plasma was collected before (baseline), at plasma peak time, and 6 and 12 h after DOAC. DRVVT was measured using the screen (LA1) and confirm (LA2) assay for lupus anticoagulant and compared with DOAC plasma levels. A reference range was calculated based on the dRVVT values of 61 healthy blood donors. Results: All DOAC significantly prolonged the dRVVT especially at higher DOAC plasma levels. The LA1 time ≥41 s had a sensitivity ≥98% to detect edoxaban, dabigatran and rivaroxaban plasma levels ≥30 ng/mL but it was only 87% for apixaban. Sensitivity was ≥98% for all DOAC with the LA2 assay ≥36 s. The negative predictive value of a DOAC plasma level <30 ng/mL and dRVVT LA2 <36 s was 99%. Conclusions: The dRVVT confirm assay (LA2) reliably detects residual DOAC plasma levels ≥30 ng/mL and could be useful to rapidly rule out relevant DOAC activity in emergency situations and to guide treatment decisions. [ABSTRACT FROM AUTHOR]

Background Acute coronary syndrome (ACS) is primarily due to obstructive coronary artery disease (CAD). Nevertheless, in 1–14% of cases, ACS is present without evidence of obstructive CAD. Coronary artery spasm is an uncommon cause of ACS. Diagnostic work-up includes acute invasive coronary angiography and afterwards provocation testing. The optimal patient management is for patients presenting with cardiogenic shock due to ACS caused by coronary artery spasm is unclear. Case summary A 67-year-old Caucasian, who underwent elective revision of hip arthroplasty, presented with ST elevations with circulatory collapse, leading to resuscitation due to anaesthesia induction. Extracorporeal membrane oxygenation (ECMO) implantation led to restoration of spontaneous circulation. Coronary angiography revealed coronary vasospasm, which was successfully treated with nitrates i.c. Later, despite of implanted ECMO, recurring haemodynamic deterioration required continuous administration of nitrates i.v. which finally resulted in the stabilization of circulatory system. Extracorporeal membrane oxygenation removal was possible 48 h after implantation and another 12 h later we extubated the patient. Furthermore, we administered calcium antagonists and an intra-cardiac defibrillator was implanted. Finally, the patient was discharged 12 days after admission with no physical or neurological restrictions after resuscitation. Discussion This unique case highlights that rare causes of severe ACS with cardiogenic shock need to be considered. Administration of vasodilators, which are not part of the standard care in cardiogenic shock, represents the adequate treatment of a patient with spasm of coronary arteries. Furthermore, the recurrence of acute coronary events must be prevented by drug and device therapy in these patients. [ABSTRACT FROM AUTHOR]

The article focuses on the dose-response relationship of direct oral anticoagulants (DOACs) at plasma levels below 100 nanograms (ng) per milliliter (mL). It describes a study that investigated the thrombin generation (TG) profiles of different DOACs at various plasma drug levels and highlights the non-linear dose-response relationship, with higher inhibition of thrombin generation observed at lower plasma levels.