Misdiagnosis of Myocardial Infarction | Journal Scan

Study Questions:

What are the sources for misdiagnosis of acute myocardial infarction (AMI) after the introduction of the universal definition of AMI?

Methods:

The investigators quantified the incidence of inconsistencies in the diagnosis of AMI using fully characterized and clinically available high-sensitivity cardiac troponin (hs-cTn) assays (hs-cTnI Abbott and hs-cTnT Roche) among 2,300 consecutive patients with suspected AMI in an international prospective multicenter study. The authors hypothesized that the approved clinical decision values (CDVs) for the two assays are not biologically equivalent and might therefore contribute to inconsistencies in the diagnosis of AMI. Findings were validated using gender-specific CDV as well as with parallel measurements of other hs-cTnI assays.

Results:

AMI was the adjudicated diagnosis in 473 patients (21%). Among these, 86 patients (18.2%) had inconsistent diagnoses using the approved uniform CDV. Using gender-specific CDV, 14.1% of female and 22.7% of male AMI patients had inconsistent diagnoses. Using biologically equivalent CDVs reduced inconsistencies to 10% (p < 0.001). These findings were confirmed with parallel measurements of other hs-cTn assays. The incidence of inconsistencies was only 7.0% for assays with CDVs that were nearly biologically equivalent. Patients with inconsistent AMI had comparable long-term mortality as compared to patients with consistent diagnoses (p = not significant), and a trend toward higher long-term mortality than patients diagnosed with unstable angina (p = 0.05).

Conclusions:

The authors concluded that the currently approved CDVs are not biologically equivalent and contribute to major inconsistencies in the diagnosis of AMI.

Perspective:

This study suggests that currently approved CDVs for cTn are not biologically equivalent, and therefore, contribute to major inconsistencies in the diagnosis of AMI. One out of five AMI patients will receive a diagnosis other than AMI if managed with the alternative hs-cTn assay. Inconsistencies seemed to be due to the fact that the approved CDV for hs-cTnI is not biologically equivalent to the approved CDV for hs-cTnT. Possible solutions include having all manufacturers use the same cohort of healthy individuals for the derivation of the respective 99th percentile of all clinical assays OR appropriately define the CDV (99th percentile) of one hs-cTn assay in a very large well-characterized cohort of healthy individuals, and to do parallel measurements with all other clinical hs-cTn assays in a disease cohort in order to establish biologically equivalent CDV.

Clinical Topics: Acute Coronary Syndromes, ACS and Cardiac Biomarkers

Keywords: Acute Coronary Syndrome, Angina, Unstable, Biological Markers, Decision Support Systems, Clinical, Diagnosis, Diagnostic Errors, Incidence, Mortality, Myocardial Infarction, Prospective Studies, Troponin, Troponin I


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