Novel Risk Prediction Scores for ED Patients with Suspected Coronary Disease

Each year, Canadian Emergency Departments (EDs) see over 600,000 patients with chest pain or other symptoms of coronary artery disease (CAD)¹. Of these patients, only ~15% are diagnosed with myocardial infarction (MI, also known as a heart attack) or are admitted for further testing ². The remaining 85% who have had MI and other high-risk diagnoses ruled out in the ED, have a short-term risk of Major Adverse Cardiac Events (MACE) being at 2.5% or less ^3,4,5. Yet, over 40% or ~204,000 of these patients are sent for extensive outpatient testing each year to identify only 6.1% of patients at risk for MACE.

This is an ineffective use of healthcare resources.

To derive, and internally validate, a novel risk prediction tool to accurately predict 30-day MACE among ED patients with chest pain in whom MI has been ruled out and who are considered for ED discharge. This risk prediction tool will guide rational, cost-effective decisions around which patients should be referred for additional cardiovascular testing after a thorough ED evaluation for chest pain. Even a modest 10% improvement in specificity of referral practices, while maintaining acceptable sensitivity, could safely translate to an annual reduction of over 50,000 unnecessary outpatient consultations and tests in Canada, thus improving access to care for patients with higher pre-test probability of coronary disease and reducing costs.

While referral to outpatient cardiology and/or testing has been associated with a 50% reduction in 1-year mortality and fewer re-hospitalizations, this phenomenon is likely due to poor clinical risk stratification^6,7. Patients who are referred to outpatient cardiology tend to be younger, have fewer comorbidities, and a lower probability of coronary disease. In contrast, the patients who do not receive cardiology follow-up are older, have multiple comorbidities, and have a higher risk of all-cause mortality ⁶. This sort of over-referral for low-risk patients burdens the healthcare system and reduces access for higher-risk patients who are most likely to benefit from such tests. 

There are several risk score assessments, including those created by Diamond and Forrster^8,9, the HEART score, Manchester Acute Coronary Syndrome (MACS) Rule, Emergency Department Assessment of Chest pain Score (EDACS)^10-14, and The Australian No Objective Testing Rule15. However, all the above assessments were created prior to the widespread availability of high-sensitivity cardiac troponin (hs-cTn) assays, which are now the gold standard^15,16. They also do not account for differences in short-term MACE risk between male and female patients, who often present with different symptoms and severity^17-21. 

This study aims to prospectively develop a risk prediction tool to accurately estimate the risk of 30-day MACE in ED patients presenting with chest pain who are eligible for discharge after having MI ruled out. This will improve on existing tools in several ways: 

1. Developed on a contemporary Canadian patient population
2. Patients are recruited AFTER MI is ruled out
3. Improved accounting for sex-related MACE risk
4. Use of high-sensitivity cardiac troponin assays
5. Integration of multiple laboratory markers to enhance risk prediction

Data is collected on patients in the EDs of academic hospitals across Canada:

• Calgary, AB: Foothills Medical Centre, South Health Campus, Rockyview General Hospital
• Vancouver, BC: Vancouver General Hospital, St. Paul’s Hospital
• Halifax, NS: QEII Health Sciences Centre
• London, ON: London Health Sciences Centre (University and Victoria Campuses)
• Kingston, ON: Kingston Health Services
• Toronto, ON: Sinai Health, Sunnybrook Research Institute
• Ottawa, ON: The Ottawa Hospital (Civic and General Campuses)

At most sites, patients will be recruited from 8am-8pm, 7 days/week while research staff are present. Eligible patients receive normal care provided by ED clinicians, including ECG and laboratory testing as per usual clinical practice. The eligible patients ED physician will fill out an online form with pertinent information for the creation of the risk assessment tool. This information includes the patient’s age, biological sex, gender, and clinical characteristics of their chest pain including the pattern, provoking and relieving factors, radiation locations, associated signs, risk factors, etc. 

For patients to be eligible for the study, they must fulfill all the following inclusion criteria and must not fulfill any of the exclusion criteria, as seen below.

Think your patient might be eligible? 

→ Click here to fill out a patient enrollment form or copy/paste this link into your browser: https://rc.med.ubc.ca/redcap/surveys/?s=MCCDJWXMDRFADE43
 

Patient Information: 

If you present to a participating ED in Canada with chest pain or suspected cardiac ischemia, you may be enrolled into this study. Participants do not need to do anything to be enrolled.

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