Patented biomarker for cardiac injury. 

cMyC to Diagnose Acute Myocardial Infarction in the Pre‐Hospital Setting

Background

Early triage is essential to improve outcomes in patients with suspected acute myocardial infarction (AMI). This study investigated whether cMyC (cardiac myosin‐binding protein), a novel biomarker of myocardial necrosis, can aid early diagnosis of AMI and risk stratification.

What is New?

In an observational, prospective diagnostic cohort study that included 776 individuals presenting with chest pain and suspected acute myocardial infarction (AMI), cMyC (cardiac myosin‐binding protein C) concentrations in blood draws obtained in the ambulance were significantly higher in patients with AMI than with other diagnoses.

Discrimination power was significantly better for cMyC than for high‐sensitivity cardiac troponin T, and cMyC at the previously published threshold of 10 ng/L for rule‐out of AMI reached 100% sensitivity and negative predictive value in patients with only 2 hours of symptoms.

What Are the Clinical Implications?

cMyC could significantly improve the early triage of patients with suspected AMI.

We have developed a diagnostic nomogram, translating the combination of clinical risk factors and cMyC concentration into a personalized probability of AMI.

Conclusions

In patients undergoing blood draws very early after symptom onset, cMyC demonstrates improved diagnostic discrimination of AMI and could significantly improve the early triage of patients with suspected AMI.
Discriminatory Power of cMyC at Different Thresholds.
Distribution of patients stratified by adjudicated diagnosis of AMI based on the prehospital cMyC concentration. x‐axis log10‐transformed. AMI indicates acute myocardial infarction; cMyC, cardiac myosin‐binding protein C; LoD, lower limit of detection.
Distribution of cMyC and hs‐cTnT concentrations in samples obtained in the ambulance, based on adjudicated final diagnosis. Boxes represent interquartile ranges; whiskers extend to 1.5×IQR from the hinges; light gray bullets are outliers. AMI indicates acute myocardial infarction; cMyC, cardiac myosin‐binding protein C; hs‐cTnT, high‐sensitivity cardiac troponin T; IQR, interquartile range; UA, unstable angina.