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Two-Hour Algorithm for Rapid Triage of Suspected Acute Myocardial Infarction Using a High-Sensitivity Cardiac
Thomas Nestelberger1,2, Jasper Boeddinghaus1,2,3, Jaimi Greenslade4,5,6
1Cardiovascular Research Institute Basel (CRIB) and Department of Cardiology, University Hospital Basel, University of Basel, Basel, Switzerland.
Insights
This study developed a 0/2-hour algorithm using high-sensitivity cardiac troponin I (hs-cTnI) to rapidly rule out or rule in acute myocardial infarction (AMI). The algorithm demonstrates high safety and efficacy for patient triage in emergency settings.
Area of Science:
- Cardiology
- Biochemistry
- Emergency Medicine
Background:
- Acute myocardial infarction (AMI) diagnosis relies on serial cardiac troponin measurements.
- Early and accurate triage of patients with suspected AMI is crucial for timely treatment and resource allocation.
Purpose of the Study:
- To derive and externally validate a 0/2-hour algorithm using the high-sensitivity cardiac troponin I (hs-cTnI)-Access assay for AMI diagnosis.
- To assess the safety and efficacy of this algorithm in a real-world emergency department setting.
Main Methods:
- Prospective enrollment of patients presenting with symptoms suggestive of AMI.
- Central adjudication of final diagnosis by two independent cardiologists.
- Measurement of hs-cTnI-Access concentrations at presentation (0-h) and after 2 hours.
Main Results:
- The 0/2-h algorithm successfully ruled out AMI in 55% of the derivation cohort (NPV 99.8%) and 77.9% in the validation cohort (NPV 99.8%).
- The algorithm ruled in AMI in 30% of the derivation cohort (PPV 73%) and 5.8% in the validation cohort (PPV 77%).
- High sensitivity (99.4% derivation, 97.7% validation) and specificity were observed for the algorithm's rule-out and rule-in criteria.
Conclusions:
- The hs-cTnI-Access 0/2-h algorithm is highly safe and effective for triaging patients with suspected AMI.
- This algorithm facilitates rapid rule-out or rule-in of AMI, potentially improving emergency department workflow.
Background:
We aimed to derive and externally validate a 0/2-h algorithm using the high-sensitivity cardiac troponin I (hs-cTnI)-Access assay.
Methods:
We enrolled patients presenting to the emergency department with symptoms suggestive of acute myocardial infarction (AMI) in 2 prospective diagnostic studies using central adjudication. Two independent cardiologists adjudicated the final diagnosis, including all available medical information including cardiac imaging. hs-cTnI-Access concentrations were measured at presentation and after 2 h in a blinded fashion.
Results:
AMI was the adjudicated final diagnosis in 164 of 1131 (14.5%) patients in the derivation cohort. Rule-out by the hs-cTnI-Access 0/2-h algorithm was defined as 0-h hs-cTnI-Access concentration <4 ng/L in patients with an onset of chest pain >3 h (direct rule-out) or a 0-h hs-cTnI-Access concentration <5 ng/L and an absolute change within 2 h <5 ng/L in all other patients. Derived thresholds for rule-in were a 0-h hs-cTnI-Access concentration ≥50 ng/L (direct rule-in) or an absolute change within 2 h ≥20 ng/L. In the derivation cohort, these cutoffs ruled out 55% of patients with a negative predictive value (NPV) of 99.8% (95% CI, 99.3-100) and sensitivity of 99.4% (95% CI, 96.5-99.9), and ruled in 30% of patients with a positive predictive value (PPV) of 73% (95% CI, 66.1-79). In the validation cohort, AMI was the adjudicated final diagnosis in 88 of 1280 (6.9%) patients. These cutoffs ruled out 77.9% of patients with an NPV of 99.8% (95% CI, 99.3-100) and sensitivity of 97.7% (95% CI, 92.0-99.7), and ruled in 5.8% of patients with a PPV of 77% (95% CI, 65.8-86) in the validation cohort.
Conclusions:
Safety and efficacy of the l hs-cTnI-Access 0/2-h algorithm for triage toward rule-out or rule-in of AMI are very high.
Trial Registration:
APACE, NCT00470587; ADAPT, ACTRN1261100106994; IMPACT, ACTRN12611000206921.
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