Related Experiment Videos
Creatine kinase subform analysis in hemodialysis patients without acute coronary syndromes
M J Robbins1, E M Epstein, S Shah
1Department of Medicine, St. John's-Queens Hospital, Elmhurst, N.Y., USA. mr7@doc.mssm.edu
Insights
New creatine kinase (CK) MB subform analysis, useful for diagnosing myocardial infarction, may lead to misdiagnosis in hemodialysis patients. This rapid test showed false positives in 29% of patients without cardiac symptoms.
Area of Science:
- Biochemistry
- Cardiology
- Nephrology
Background:
- Elevated creatine kinase (CK) and CK MB levels are crucial for diagnosing acute myocardial infarction (MI).
- Rapid CK MB subform analysis offers a sensitive and specific method for MI diagnosis in the general population.
- Standard CK and CK MB analyses are being replaced by rapid subform analysis in some centers for guiding chest pain patient therapy.
Purpose of the Study:
- To investigate whether CK MB subform analysis could yield abnormal results in hemodialysis patients without acute coronary syndromes.
- To determine the accuracy of CK MB subform analysis for diagnosing acute myocardial infarction in hemodialysis patients.
Main Methods:
- CK MB subforms were analyzed in 52 hemodialysis patients without recent cardiac symptoms undergoing routine treatment.
- Standard clinical criteria for diagnosing acute myocardial infarction were applied to the subform analysis results.
Main Results:
- CK MB subform analysis indicated myocardial infarction in approximately 29% of the hemodialysis patients studied.
- These patients had no recent cardiac symptoms, suggesting potential for false positive results.
Conclusions:
- CK MB subform analysis may lead to erroneous diagnosis of acute myocardial infarction in hemodialysis patients.
- Clinical application of this rapid diagnostic tool requires careful consideration in patients undergoing hemodialysis.
Abstract:
The finding of elevated levels of creatine kinase (CK) and its myocardial isoenzyme (CK MB) in the blood of patients with acute chest pain syndromes is a key factor in making the diagnosis of acute myocardial infarction. With the widespread use of thrombolytic therapy and emergency angioplasty, the ability to make a rapid and accurate diagnosis of myocardial infarction is critical. A new rapid method for analysis of the subforms of the MB isoenzyme has been shown to be sensitive and specific for the diagnosis of myocardial infarction in the general population. Because of its rapidity it has been replacing standard analyses of total CK and CK MB in some centers in guiding the initial therapy of patients with chest pain. Levels of CK MB can be abnormally elevated in hemodialysis patients even in the absence of acute myocardial necrosis. This study was undertaken in order to determine if subform analysis of the MB isoenzyme could similarly be abnormal in hemodialysis patients without acute coronary syndromes. CK MB subforms were analyzed in 52 patients without any recent cardiac symptoms who came into the dialysis unit for a routine hemodialysis treatment. We then applied the same criteria for the diagnosis of an acute myocardial infarction as would be used clinically. In this population, the subform analysis was surprisingly consistent with myocardial infarction in approximately 29% of the patients. Thus, subform analysis appears likely to result in an erroneous diagnosis of acute myocardial infarction in patients on hemodialysis.