Prognostic implications of creatine kinase-MB measurements in ST-segment elevation myocardial infarction patients treated with primary percutaneous coronary intervention

Background Peak creatine kinase (CK)-MB concentration is related to reperfusion success and clinical outcomes after fibrinolytic therapy for acute myocardial infarction. However, prognostic implications of CK-MB measurements after primary percutaneous coronary intervention (PCI), which provides more predictable and consistent reperfusion, are unknown. Methods We pooled 2,042 primary PCI-treated ST-segment elevation myocardial infarction (STEMI) patients from 3 trials with serial core laboratory-determined CK-MB measurements; 1,799 patients (88.1%) who survived to 36 hours and had ≥4 CK-MB measurements were studied. Cox regression modeling was performed to quantify the association between peak CK-MB concentration (and area under the time-concentration curve [AUC]) and mortality at 6 months, and death or congestive heart failure at 90 days. Results The median (25th-75th percentiles) peak CK-MB concentration and AUC measurement through 36 hours were 239 (109-429) ng/mL and 4,263 (2,081-7,124) ng/(mL h), respectively. By multivariable analysis, peak CK-MB concentration and AUC measurement were independently associated with 6-month mortality (adjusted hazard ratio [HR] 1.15, 95% CI 1.05-1.25, per 100-ng/mL increase, P =.002; and adjusted HR 1.09, 95% CI 1.03-1.14, per 1,000-ng/[mL h] increase, P <.001, respectively) and 90-day death or congestive heart failure (adjusted HR 1.26, 95% CI 1.18-1.34, P <.001; and adjusted HR 1.15, 95% CI 1.11-1.19, P <.001, respectively). Conclusions Peak CK-MB concentration and AUC measurement are independent predictors of 3- to 6-month cardiovascular outcomes in primary PCI-treated STEMI patients. Our findings guide application of these measurements as efficacy end points in early-phase studies evaluating new therapies for STEMI.