OBJECTIVE: To demonstrate that a positive CK-MB in the emergency department (ED) predicts an increased risk for complications of myocardial ischemia in patients admitted to the hospital for evaluation of chest pain. METHODS: 53 academic and community hospital EDs participated in this prospective observational cohort analysis of 5,120 patients with chest pain without ST-segment elevation on the initial ED 12-lead electrocardiogram. All patients were admitted for evaluation of chest pain in one of the participating hospitals as part of the National Cooperative CK-MB Project. Patients were stratified by whether or not they had an elevated CK-MB level in the ED. CK-MB measurements were made on ED presentation and two hours later. Patient medical records were reviewed for inpatient diagnoses--myocardial infarction (MI) or other diagnosis--and for ischemic complication--cardiac-related death, recurrent or delayed in-hospital MI, significant ventricular arrhythmias, new conduction defects, congestive heart failure, and cardiogenic shock. RESULTS: 369 (7.2%) of the 5,120 patients had MI. The proportion of patients with any complication in the MI group was 24%, while the complication rate in the non-MI group was 0.4%. In all patients, regardless of final diagnosis, the relative risk of any complication was 16.1 (95% CI 11.0-23.6) in those with a positive ED CK-MB versus negative ED CK-MB patients. Similarly, the relative risk of death was 25.4 (95% CI 10.8-60.2) in positive ED CK-MB versus negative ED CK-MB patients. CONCLUSIONS: Multicenter data support the hypothesis that CK-MB measurements can help risk-stratify ED chest pain patients whose initial ECGs are without diagnostic ST-segment elevation.
OBJECTIVE: To demonstrate that a positive CK-MB in the emergency department (ED) predicts an increased risk for complications of myocardial ischemia in patients admitted to the hospital for evaluation of chest pain. METHODS: 53 academic and community hospital EDs participated in this prospective observational cohort analysis of 5,120 patients with chest pain without ST-segment elevation on the initial ED 12-lead electrocardiogram. All patients were admitted for evaluation of chest pain in one of the participating hospitals as part of the National Cooperative CK-MB Project. Patients were stratified by whether or not they had an elevated CK-MB level in the ED. CK-MB measurements were made on ED presentation and two hours later. Patient medical records were reviewed for inpatient diagnoses--myocardial infarction (MI) or other diagnosis--and for ischemic complication--cardiac-related death, recurrent or delayed in-hospital MI, significant ventricular arrhythmias, new conduction defects, congestive heart failure, and cardiogenic shock. RESULTS: 369 (7.2%) of the 5,120 patients had MI. The proportion of patients with any complication in the MI group was 24%, while the complication rate in the non-MI group was 0.4%. In all patients, regardless of final diagnosis, the relative risk of any complication was 16.1 (95% CI 11.0-23.6) in those with a positive ED CK-MB versus negative ED CK-MB patients. Similarly, the relative risk of death was 25.4 (95% CI 10.8-60.2) in positive ED CK-MB versus negative ED CK-MB patients. CONCLUSIONS: Multicenter data support the hypothesis that CK-MB measurements can help risk-stratify ED chest painpatients whose initial ECGs are without diagnostic ST-segment elevation.