Cost Conscious Project: How Many Troponins Does It Take? Rola Khedraki

Study Question: Do we really need three troponins in low risk patients?

Who is low risk? Low-risk patients for ACS are those with no hemodynamic derangements or arrhythmias, a normal or near-normal ECG, and negative initial cardiac injury markers.

Objectives Purpose of the study was to ascertain whether troponin tests are requested appropriately.

What’s the Problem and What’s the Evidence? Housestaff often order 3 or sometimes even 4 troponin values to rule out MI in these low risk patients However, for patients who present early (within 6 hours of symptom onset), with negative initial troponin, a second negative measurement 6-8h later is adequate to exclude ACS. And in fact, patients who arrive >8h after symptom onset may only need one negative biomarker to exclude ACS. Amsterdam, et al. Testing of low risk patients presenting to the emergency department with chest pain. Circulation. 2010; 122:

Troponin Assay Occurrence of first increase values after MI symptom onset: 50% of patients at 3.5h75% of patients at 4.3h95% of patients at 7h Mair J, Morandell D, Genser N, Lechleitner P, Dienstl F, Puschendorf B: Equivalent early sensitivities of myoglobin, creatine kinase MB mass, creatine kinase isoform ratios, and cardiac troponins I and T for acute myocardial infarction. Clin Chem 1995;41: A negative troponin assay does not exclude diagnosis of unstable angina if obtained within less than 6h

Cost and Implications Healthcare Bluebook: $26 – Can cost 3-5x as much depending on the location Adds to length of stay Inappropriate utilization of resources: Someone has to check on the levels (overnight residents, etc.), nursing staff to draw level Add in cost of EKG with each troponin Pain to patient (frequent lab draw) Test not 100% specific  could result in minimally positive levels and starting antiplatelet therapy  possibly unnecessary complications (esp., in elderly or those with high risk of falls, aortic dissection)

Methods ED to general medicine admissions over time span of 6 days Patients who presented with chest pain (not necessarily chief complaint) All had normal EKG, hemodynamically stable, initial troponin negative

Results Presenting associated symptoms* Hours after symptom onset # of Troponins Final diagnosisAntiplatelets? Epigastric pain18h2 (0:00, 6:00) ConstipationNO Generalized fatigue 24h4 (0:00, 10:00, 16:00, 24:00) InfluenzaNO Syncope8h3 (0:00, 6:00, 12:00) DehydrationYES Fall1h3 (0:00, 4:00, 10:00) Femoral fractureNO Shortness of breath 36h3 (0:00, 6:00, 14:00) COPD exacerbationNO Fall18h2 (0:00, 12:00) Mechanical fallYES Palpitations48h3 (0:00, 6:00, 12:00) Atrial fibrillationNO *All patients presented with chest pain and the following associated symptoms

Discussion Management strategy should be individualized based on clinical presentation and assessment of risk There is little value in obtaining delayed troponin compared to testing at presentation.

Cost Effective Approaches Low risk patients are increasingly managed with accelerated diagnostic protocols. Patients with negative findings complete the protocol with a confirmatory test to exclude ischemia (exercise treadmill or cardiac imaging) done either inpatient or within 72h of discharge.