Creatine Kinase during Non-ST-Segment Elevation Acute Coronary Syndromes is Associated with Major Bleeding

Abstract

AbstractBackgroundIt was recently reported that highly elevated plasma activity of the ADP-scavenging enzyme creatine kinase (CK), to >10 times the upper reference limit (URL), is independently associated with fatal or non-fatal bleeding during treatment for ST-segment elevation myocardial infarction (OR 2.6 [95% CI, 1.8 to 2.7]/log CK increase). Evidence indicates that CK attenuates ADP-dependent platelet aggregation. This study investigates whether moderately elevated CK in non-ST-segment elevation acute coronary syndromes (NSTE-ACS) is associated with major bleeding.MethodsThe Thrombolysis In Myocardial Ischemia (TIMI) 3B trial compared rt-PA (35 to 80 mg) with placebo, and early catheterization with conservative management in patients with NSTE-ACS. Main outcomes of the current study are the independent association of peak plasma CK (CKmax) with adjudicated fatal or non-fatal major bleeding (primary), and with combined major bleeding, stroke, and all-cause mortality (secondary) in multivariable binomial logistic regression analysis, with co-variables including age, sex, BMI, SBP, creatinine, and treatment assignment. Discrimination was assessed with C-statistics.ResultsThe study included 1473 patients (66% men, 80% white, mean age 59 y, SE 0.3). CKmax ranged between 15 and 19045 IU/L (mean (SE), 450(24) IU/L; i.e. 2 times URL). Major bleeding occurred in 2.0% (mean age 65(1.3) y; mean CKmax 1015(318) IU/L; 6 times URL), and the combined outcome in 4.3% of the patients, adjusted OR per log CK increase respectively 3.1 [1.6 to 5.8] for major bleeding, and 3.9 [2.5 to 6.1] for the combined outcome; C-index 0.8 for both outcomes.DiscussionThe presented data add to the existing evidence that proportionate to its plasma activity, the ADP-binding enzyme CK is strongly and independently associated with non-fatal and fatal major bleeding during ACS treatment. CK might increase the accuracy of prediction models for major bleeding in patients treated with antithrombotic or thrombolytic drugs for ACS.ClinicalTrials.gov identifierNCT00000472