# Comparative Effectiveness of Early Diagnostic and Disposition Strategies for Suspected Acute Coronary Syndrome

> **NIH NIH R01** · UNIVERSITY OF PENNSYLVANIA · 2020 · $759,051

## Abstract

Project Summary
The ultimate goal of this proposal is to improve outcomes after an emergency department (ED) evaluation for
suspected acute coronary syndrome (ACS). ACS includes acute myocardial infarction (AMI) and unstable
angina, and is the leading cause of worldwide mortality and morbidity. Suspected ACS is the second most
frequent reason for U.S. ED visits and accounts for over 7 million annual encounters. The minority (13%) of ED
chest pain visits are related to ACS, and diagnosis is challenging with high clinical and medico-legal stakes.
To minimize missed ACS, the American Heart Association suggests non-invasive cardiac testing (e.g. stress
electrocardiogram [ECG], stress echocardiogram [echo], stress myocardial perfusion [MP], or coronary
computed tomography angiogram [CCTA]) within 72 hours, after serial biomarkers have excluded AMI.
Furthermore, patients with suspected ACS are often admitted to an inpatient bed or observation unit to
facilitate early non-invasive testing and to mitigate the risk of dangerous complications of ischemic heart
disease. Evaluation of suspected ACS is the top reason for U.S. short-stay (<48 hrs) inpatient and observation
admissions, and accounts for $3-10 billion in hospital costs per year.
However, there is no evidence that early non-invasive testing or hospital based evaluation benefits
patients. Current use of early non-invasive tests increases rates of invasive coronary angiography and
revascularization without reducing AMI risk. The potential benefits of hospital admission in low-risk patients
appear to be marginal (<0.2% cardiac event rate during admission). The widely varying rates of non-invasive
testing (6x difference between top and bottom quartile hospitals) and hospitalization (7x difference between top
and bottom quartile hospitals) for suspected ACS suggest pervasive uncertainty about the optimal approach.
Using prospective observational data on ~170,000 patient encounters within an integrated health system, we
will assess five early diagnostic (stress ECG, stress echo, stress MP, CCTA, or NO non-invasive testing) and
three disposition (inpatient, observation, discharge) strategies:
Aim 1. Compare 30-day outcomes of early diagnostic testing strategies for suspected ACS
Aim 2. Compare 30-day outcomes of disposition strategies for suspected ACS
Aim 3. Assess whether pre-test risk affects the comparative effectiveness of early diagnostic and
 disposition strategies for suspected ACS
Aim 4. Compare cost-effectiveness of early diagnostic and disposition strategies for suspected ACS
The Aims address questions fundamental to any evaluation for suspected ACS: 1. What test if any is needed?
2. Is admission beneficial? 3. How does patient pre-test risk modify management? Aim 4 will inform policy
makers and payers about the comparative value of different strategies.

## Key facts

- **NIH application ID:** 9949775
- **Project number:** 5R01HL134647-05
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Benjamin C Sun
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $759,051
- **Award type:** 5
- **Project period:** 2017-08-18 → 2023-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9949775

## Citation

> US National Institutes of Health, RePORTER application 9949775, Comparative Effectiveness of Early Diagnostic and Disposition Strategies for Suspected Acute Coronary Syndrome (5R01HL134647-05). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/9949775. Licensed CC0.

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