Abstract
BackgroundSerial conventional cardiac troponin (cTn) measurements 6–9 hours apart are recommended for non-ST-elevation MI (NSTEMI) diagnosis. We sought to develop a pathway with 3-hour changes for major adverse cardiac event (MACE) identification and assess the added value of the HEART [History, Electrocardiogram (ECG), Age, Risk factors, Troponin] score to the pathway.MethodsWe prospectively enrolled adults with NSTEMI symptoms at two-large emergency departments (EDs) over 32-months. Patients with STEMI, unstable angina and one cTn were excluded. We collected baseline characteristics, Siemens Vista conventional cTnI at 0, 3 or 6-hours after ED presentation; HEART score predictors; disposition and ED length of stay (LOS). Adjudicated primary outcome was 15-day MACE (acute MI, revascularization, or death due to cardiac ischemia/unknown cause). We analyzed multiples of 99th percentile cut-off cTnI values (45, 100 and 250ng/L).Results1,683 patients (mean age 64.7 years; 55.3% female; median LOS 7-hours; 88 patients with 15-day MACE) were included. 1,346 (80.0%) patients with both cTnI≤45 ng/L; and 155 (9.2%) of the 213 patients with one value≥100ng/L but both<250ng/L or ≤20% change did not suffer MACE. Among 124 patients (7.4%) with one of the two values>45ng/L but<100ng/L based on 3 or 6-hour cTnI, one patient with absolute change<10ng/L and 6 of the 19 patients with≥20ng/L were diagnosed with NSTEMI (patients with Δ10-19ng/L between first and second cTnI had third one at 6-hours). Based on the results, we developed the Ottawa Troponin Pathway (OTP) with a 98.9% sensitivity (95% CI 93.8–100%) and 94.6% specificity (95% CI 93.3–95.6%). Addition of the HEART score improved the sensitivity to 100% (95% CI 95.9–100%) and decreased the specificity to 26.5% (95% CI 24.3–28.7%).ConclusionThe OTP with conventional cTnI 3-hours apart, should lead to better NSTEMI identification particularly those with values >99th percentile, standardize management and reduce the ED LOS.
Highlights
Chest pain is the second most common emergency department (ED) presenting complaint.[1]
We chose stratification values of >45 ng/L (URL), >100ng/L and >250ng/ L, values of 10, 20 and 30 ng/L for absolute changes, and multiples of 10% for relative changes with 20% as the main relative change based on inhouse assay precision, review of guidelines, review of troponin reference change value (RCV) reported in the literature and international recommendations. [9, 12, 14] We developed the Ottawa Troponin Pathway to achieve highest sensitivity based on two troponin values three hours apart
Based on the above analysis, we developed the Ottawa Troponin Pathway (OTP; Fig 3) for troponin testing using the Siemens Vista conventional cardiac troponin I (cTnI) assay for patients with suspected non-ST-elevation MI (NSTEMI)
Summary
ACS caused by acute myocardial ischemia, includes unstable angina, ST-elevation and non-ST elevation myocardial infarction (STEMI, NSTEMI), and is associated with substantial morbidity and mortality. Among those diagnosed with ACS, 70% have NSTEMI which are diagnosed using cardiac troponin (cTn) assays.[4] Approximately 85% of all patients presenting to the ED with chest pain will be discharged home.[5] accurate yet quick disposition decision for this common condition is a critical issue that affects ED crowding. We sought to develop a pathway with 3-hour changes for major adverse cardiac event (MACE) identification and assess the added value of the HEART [History, Electrocardiogram (ECG), Age, Risk factors, Troponin] score to the pathway.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
