Are Serial Electrocardiograms Additive to SeriAl Second-generations Troponins in Predicting Acute CoronAry Syndromes in PatienTs With Undifferentiated cHest Pain

Chest pain is one of the most common symptoms evaluated in the Emergency Department (ED). One of the primary diagnostic concerns during the evaluation of this presentation is whether there is evidence of acute coronary syndromes (ACS) as ACS is a major risk factor for short- and long-term major adverse cardiovascular events (MACE, defined as acute myocardial infarction, revascularization, or all-cause death). Two of the cornerstones of the guidelines-based evaluation of this patient group are serial electrocardiograms (ECG) and troponin measurements (a serological marker of myocardial ischemia), which have shown to be both independently and incrementally predictive of ACS. Recently, second-generation troponin assays have been adopted into clinical practice as they have higher sensitivity and specificity for ACS compared to older assays. Given the increased diagnostic accuracy of these novel second-generation assays, the proposed study's research question is to investigate whether serial ECG changes significantly increase the diagnostic accuracy of serial second-generation troponin changes in predicting MACE in patients presenting with symptoms consistent with ACS. In order to investigate this question, we originally proposed an observational pilot study ancillary to the HEART Pathway trial (WFUHS IRB00021074), a funded randomized controlled trial investigating a recently developed decision aid tool (the HEART score) designed to identify patients being evaluated for chest pain that can safely forgo further objective testing. We proposed to add the collection of two additional 12-lead ECGs to the protocol in the HEART Pathway trial, which included serial second-generation troponin collection, in order to generate pilot data regarding the research question. As recruitment for the HEART Pathway trial ended in February 2014, we now propose to continue enrollment for the ASAP CATH study independently, as a prospective observational study evaluating the additional prognostic value of serial ECGs to standard care in patients with chest pain being evaluated for acute coronary syndromes in the Emergency Department.

Objective:

The goal of this project is to produce preliminary data to investigate whether the presence or absence of serial ECG changes suggestive of myocardial ischemia aids in reclassifying participants' risk for MACE and objective evidence of ACS over and above serial second-generation troponin testing.

Methods:

Adult patients, over 21 years old, presenting to WFBMC ED with chest pain or symptoms concerning for ACS, in which the provider orders cardiac biomarkers and an ECG will be eligible for enrollment. We aim to add serial ECG analysis (one at the time of study enrollment and a second at the time of the study blood draw) to the protocol in the proposed study. The primary outcomes are major adverse cardiovascular events (MACE) at 30 days and evidence of acute myocardial ischemia via objective cardiac testing performed during the index hospitalization.

Inclusion criteria

• Age greater than or equal to 21 years of age at the time of enrollment
• Chest discomfort or other symptoms consistent with possible ACS as indicated by the treating physician after obtaining an ECG and cardiac biomarkers for the patient's evaluation
• The treating physician feels the patient could be discharged home if cardiac disease was excluded

Exclusion criteria

• Evidence of ST-elevation myocardial infarction (STEMI) or left bundle branch block (LBBB) on initial ECG
• Left ventricular systolic dysfunction (history of left ventricular ejection fraction <40% or active symptoms of congestive heart failure)
• New or uncontrolled ventricular arrhythmias on initial ECG
• Hemodynamic instability: heart rate > 120 bpm or < 40 bpm and/or systolic blood pressure <100 mmHg
• Hypoxemia (oxygen saturation <90% on room air or normal home oxygen flow rate)
• Terminal diagnosis with life expectancy less than 1 year
• A non-cardiac medical, surgical, or psychiatric illness determined by the provider to require admission, increase risk of objective cardiac testing, or prevent immediate discharge following negative testing.
• Prior enrollment
• Incapacity or unwillingness to provide consent and comply with study procedures