Predictors for heparin resistance in patients undergoing coronary artery bypass grafting.
Heparin resistance (HR) is a common event in cardiac operations. At present, no clear recognition of the risk factors for HR has been reached. The aim of this study was to determine a predictive model for HR, based on the preoperative patient's profile. Two hundred consecutive patients scheduled for elective coronary artery bypass operations were enrolled in a prospective trial. Demographics, type of preoperative anticoagulation therapy and preoperative coagulation profile were collected and statistically analysed with respect to the evidence of a HR. Heparin resistance was defined as at least one activated clotting time < 400 s after heparinization and/or the need for purified antithrombin III (AT-III) administration. With a multivariate analysis we could identify five predictors for HR: AT-III < or = 60%; preoperative subcutaneous heparin therapy; intravenous heparin therapy; platelet count > or = 300000 cells/mm3; age > or = 65 years. We conclude that HR is a predictable event. In the presence of all the risk factors, the likelihood of HR is 99%; in the absence of all of them, it is 10%. Predicting HR allows us to apply many possible therapeutic strategies.
Ranucci
M
M
Department of Cardiovascular Anaesthesia, University of Milan, San Donato Hospital, Italy. m.ranucci@galactica.it
Isgrò
G
G
Cazzaniga
A
A
Soro
G
G
Menicanti
L
L
Frigiola
A
A
D000368:Aged; D000990:Antithrombin III / Q000187:drug effects; D001777:Blood Coagulation / Q000187:drug effects; D001026:Coronary Artery Bypass; D004351:Drug Resistance; D005260:Female; D006493:Heparin / Q000627:therapeutic use*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010976:Platelet Count / Q000187:drug effects; D011446:Prospective Studies; D012307:Risk Factors; D014914:Whole Blood Coagulation Time
D000990:Antithrombin III; D006493:Heparin