Rapid Assessment of Possible ACS in the Emergency Department With High-Sensitivity Troponin T - RAPID-TnT

Contribution To Literature:

The RAPID-TnT trial showed that a rapid hs-TnT protocol is noninferior at preventing death or myocardial infarction.

Description:

The goal of the trial was to evaluate a 0/1 hour high-sensitivity troponin T (hs-TnT) protocol compared with a 0/3 hour hs-TnT protocol among patients presenting to the emergency department with a chest pain syndrome.

Study Design

  • Randomized
  • Parallel

Patients presenting to the emergency department with chest pain were randomized to a 0/1 hour hs-TnT protocol “intervention” (n = 1,689) versus a 0/3 hour hs-TnT protocol “standard of care” (n = 1,689).

In the 0/1 hour hs-TnT group, the lower level of detection was 5 ng/L. If baseline value was ≥52 ng/L or delta ≥5 ng/L, the patient ruled in. If baseline value was 13-51 ng/L or delta 3-4 ng/L, the patient was observed further. If baseline value was <5 ng/L or baseline value was ≤12 ng/L and delta <3 ng/L, the patient ruled out.

In the 0/3 hour hs-TnT group, the lower level of detection was masked to exclude values below 29 ng/L.

If any value was >29 ng/L, known coronary disease, or ongoing pain, the patient was admitted. If all values were ≤29 ng/L and no pain, the patient was discharged.

  • Total number of enrollees: 3,378
  • Duration of follow-up: 30 days
  • Mean patient age: 59 years
  • Percentage female: 47%
  • Percentage with diabetes: 17%

Inclusion criteria:

  • ≥18 years of age
  • Clinical features of chest pain or suspected acute coronary syndrome
  • Baseline electrocardiogram not definitive for coronary ischemia

Exclusion criteria:

  • Admission for nonchest pain reason
  • Transfer from another hospital
  • Chest pain within 30 days of last presentation
  • On permanent dialysis
  • Unable to complete clinical history questionnaire due to language or comorbidity

Principal Findings:

The primary net outcome, death or myocardial infarction at 30 days, occurred in 1.0% of the intervention group compared with 1.0% of the standard care group (p for noninferiority = 0.006).

Secondary outcomes:

  • Discharge from the emergency department: 45.1% in the intervention group vs. 32.3% in the standard care group (p < 0.001)
  • Functional cardiac testing: 7.5% in the intervention group vs. 11.0% in the standard care group (p < 0.001)
  • Myocardial infarction (type 4a or 5): 1.6% in the intervention group vs. 1.0% in the standard care group (p = 0.004)
  • Rehospitalization for coronary revascularization, heart failure, stroke, or arrhythmia at 30 days: 1.4% of the intervention group compared with 0.9% of the standard care group (p = 0.19)

Interpretation:

Among patients presenting to the emergency department with a chest pain syndrome, a 0 and 1-hour hs-TnT protocol was noninferior to standard of care. Rapid hs-TnT was associated with more discharges from the emergency department and need for less functional testing; however, there was a greater incidence of procedural-related myocardial infarction in the rapid hs-TnT group. While further study is needed, a rapid protocol utilizing hs-TnT appears to be a safe mechanism to allow for early discharge of low-risk patients from the emergency department.

References:

Chew DP, Lambrakis K, Blyth A, et al. A Randomized Trial of a 1-Hour Troponin T Protocol in Suspected Acute Coronary Syndromes: The Rapid Assessment of Possible ACS In the Emergency Department With High Sensitivity Troponin T (RAPID-TnT) Study. Circulation 2019;Sep 3:[Epub ahead of print].

Presented by Dr. Derek Chew at the European Society of Cardiology Congress, Paris, France, September 3, 2019.

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Clinical Topics: Acute Coronary Syndromes, Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Prevention, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Acute Heart Failure

Keywords: ESC Congress, ESC 19, Acute Coronary Syndrome, Arrhythmias, Cardiac, Cardiology Interventions, Chest Pain, Coronary Disease, Electrocardiography, Emergency Service, Hospital, Heart Failure, Myocardial Infarction, Secondary Prevention, Standard of Care, Stroke, Troponin, Troponin T


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