title: Reliability of thromboelastometry for detecting the safe coagulation threshold in patients taking acenocoumarol after elective heart valve replacement.
abstract: BACKGROUND
  Reversal of anticoagulation can be needed in patients undergoing heart valve surgery. ROTEM® has been correlated with international normalized ratio (INR) in patients on warfarin but not with patients on acenocoumarol. This study investigates the reliability of ROTEM® for detecting INR values below the 1.5 threshold in patients on acenocoumarol therapy.
  
  
  METHODS
  Patients on oral anticoagulation with acenocoumarol after elective heart valve replacement were prospectively included in the study. INR and the ROTEM® were measured simultaneously. ROTEM® parameters included coagulation time, clot formation time, alpha angle, and maximal clot firmness after tissue factor activation (EXTEM). Concordance between INR and ROTEM® was analyzed by Lin's concordance coefficient (LCC) and the correlation with Spearman's rho.
  
  
  RESULTS
  Fifty-four consecutive patients (40 female; median age 67years) were included. Clotting time (CT) was the parameter that best correlated with INR (r=0.81, p<0,001), and LCC was substantial (0.67). CT was able to predict INR values above or below 1.5: area under curve=0.998. CT≥84seconds, corresponding to a cut-off for likelihood ratio (LR+)=5, had a sensitivity and specificity of 100% and 80%, respectively, to detect an INR below 1.5. For the same INR threshold, CT≥84seconds had a predictive positive value of 92.9% and a predictive negative value of 100%.
  
  
  CONCLUSIONS
  Our preliminary results suggest that CT≥84seconds in the EXTEM ROTEM® test is a feasible method for predicting an insufficient reversion of oral anticoagulant therapy in patients taking acenocoumarol after elective heart valve surgery.
authors.affiliation: Anesthesia Department, IDIBAPS, Hospital Clinic of Barcelona, Villaroel, 170, Barcelona, Spain. Electronic address: ablasi@clinic.ub.es.
authors.forename: Annabel
authors.initials: A
authors.lastname: Blasi
authors.affiliation: Anesthesia Department, Hospital Clinic of Barcelona, Villaroel, 170, Barcelona, Spain. Electronic address: gamunoz@clinic.ub.es.
authors.forename: Guido
authors.initials: G
authors.lastname: Muñoz
authors.affiliation: Anesthesia Department, Hospital Clinic of Barcelona, Villaroel, 170, Barcelona, Spain. Electronic address: desoto@clinic.ub.es.
authors.forename: Ines
authors.initials: I
authors.lastname: de Soto
authors.affiliation: Anesthesia Department, Hospital Clinic of Barcelona, Villaroel, 170, Barcelona, Spain. Electronic address: rmellado@clinic.ub.es.
authors.forename: Ricard
authors.initials: R
authors.lastname: Mellado
authors.affiliation: Anesthesia Department, Hospital Clinic of Barcelona, Villaroel, 170, Barcelona, Spain. Electronic address: ptaura@clinic.ub.es.
authors.forename: Pilar
authors.initials: P
authors.lastname: Taura
authors.affiliation: Biostatistics and Data Management Core Facility, IDIBAPS, Biostatistics Unit, Faculty of Medicine, Universitat Autònoma de Barcelona, Hospital Clinic, Villaroel, 170, Barcelona, Spain. Electronic address: jose.rios@uab.cat.
authors.forename: Jose
authors.initials: J
authors.lastname: Rios
authors.affiliation: Anesthesia Department, Hospital Clinic of Barcelona, Villaroel, 170, Barcelona, Spain. Electronic address: jbalust@clinic.ub.es.
authors.forename: Jaume
authors.initials: J
authors.lastname: Balust
authors.affiliation: Anesthesia Department, Hospital Clinic of Barcelona, Villaroel, 170, Barcelona, Spain. Electronic address: jbeltran@clinic.ub.es.
authors.forename: Joan
authors.initials: J
authors.lastname: Beltran
mesh_terms: D000074:Acenocoumarol / Q000008:administration & dosage* / Q000009:adverse effects; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects; D004334:Drug Administration Schedule; D016903:Drug Monitoring / Q000379:methods; D004361:Drug Tolerance; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D019106:Postoperative Hemorrhage / Q000097:blood* / Q000517:prevention & control*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013916:Thrombelastography / Q000379:methods*; D013923:Thromboembolism / Q000097:blood / Q000175:diagnosis / Q000517:prevention & control*; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants; D000074:Acenocoumarol
keywords: acenocumarol; thromboelastometry