Related Experiment Videos
Leukocytosis: a new look at an old marker for acute myocardial infarction
S M Green1, J Vowels, B Waterman
1Department of Emergency Medicine, Loma Linda University School of Medicine, CA, USA.
Insights
Elevated white blood cell count (leukocytosis) is linked to acute myocardial infarction (AMI) in patients with unclear ECGs. Combining leukocytosis with CK-MB testing may improve AMI diagnosis accuracy.
Area of Science:
- Cardiology
- Clinical Diagnostics
- Biomarker Analysis
Background:
- Acute myocardial infarction (AMI) diagnosis can be challenging with nondiagnostic electrocardiograms (ECGs).
- Biomarkers like creatine kinase-MB (CK-MB) are crucial, but their isolated use may have limitations.
- Leukocytosis, an elevated white blood cell count, is a common finding in acute illness and warrants investigation for its diagnostic role in AMI.
Purpose of the Study:
- To evaluate the diagnostic performance of leukocytosis for identifying AMI in patients presenting with nondiagnostic ECGs.
- To assess the independent predictive value of white blood cell (WBC) count for AMI.
- To determine if combining WBC count with CK-MB improves diagnostic accuracy for AMI.
Main Methods:
- Retrospective analysis of patients admitted for rule-out AMI with nondiagnostic ECGs.
- Calculation of sensitivity, specificity, and predictive values for total CK, CK-MB, WBC count, and absolute neutrophil count (ANC).
- Construction of receiver operating characteristic (ROC) curves and evaluation of marker combinations using logistic regression.
Main Results:
- Leukocytosis was significantly higher in patients with AMI (11.1 vs 8.8 x 10(9)/L).
- For nondiagnostic ECGs, CK-MB had 73% sensitivity and 93% specificity; WBC count had 35% sensitivity and 85% specificity.
- Combining elevated CK-MB or WBC count increased sensitivity to 88% (79% specificity); combining both increased specificity to 99% (20% sensitivity).
Conclusions:
- Leukocytosis is a significant, independent predictor of AMI, though a weak one on its own.
- The combination of WBC count and CK-MB may offer enhanced diagnostic value compared to CK-MB alone in suspected AMI.
- Further research is needed to define the prognostic role of WBC count in clinical decision-making for AMI.
Objective:
To determine the test performance of leukocytosis for identifying acute myocardial infarction (AMI) in patients with nondiagnostic ECGs, admitted to rule out AMI.
Methods:
A retrospective, comparative test performance study was conducted using patients admitted to a university teaching hospital to rule out AMI. Clinical and laboratory information was reviewed and hospital laboratory ranges were used to define threshold elevations: total creatine kinase (CK), 275 U/L; CK-MB, 7.5 micrograms/L ; white blood cell (WBC) count, 11.5 x 10(9)/L; and absolute neutrophil count (ANC), 8.0 x 10(9). Sensitivity, specificity, and predictive values of the total CK, CK-MB, WBC count, and ANC were calculated, and receiver operating characteristic (ROC) curves constructed. Test performances of marker combinations also were determined.
Results:
The initial WBC count was significantly higher for the subjects who had AMI (11.1 vs 8.8 x 10(9)/L, p < 0.001). For the 688 subjects who had nondiagnostic ECGs, sensitivities for the initial total CK, CK-MB, WBC, and ANC were 39%, 73%, 35%, and 36%, respectively, while the corresponding specificities were 94%, 93%, 85%, and 86%. Logistic regression analysis confirmed leukocytosis as an independent predictor of AMI (adjusted odds ratio 4.08, 95% CI 1.73-9.63). While CK-MB alone was 73% sensitive for AMI, the decision rule of either an elevated CK-MB or an elevated WBC count increased this sensitivity to 88% (corresponding specificity 79%). Similarly, while CK-MB alone was 93% specific for AMI, the combination of an elevated CK-MB and an elevated WBC count increased this specificity to 99% (corresponding sensitivity 20%).
Conclusions:
Leukocytosis is significantly associated with AMI, and is a weak but independent laboratory predictor of this condition. In this preliminary study of admitted patients suspected of AMI, the combination of the WBC and the CK-MB may have additional diagnostic value over an isolated CK-MB result. Neither parameter in isolation was satisfactorily sensitive for AMI. Prognostic assessment of the role of the WBC count in clinical decision making should address its complementary role to that of other clinical and ancillary test parameters.