Many patients with chest pain who were discharged from the emergency department saw no benefit from subsequent stress testing

05/11/2019

When a patient suffering from chest pain is discharged from the emergency department, they are often sent for non-invasive testing. But according to researchers at ICES, a non-profit research institute that uses population-based health information to produce knowledge on a broad range of healthcare issues, many of those patients don’t benefit from the tests because they are at low risk of heart attack or cardiovascular death.

Non-invasive testing has historically been performed on patients with chest pain who are discharged from the emergency department because physicians believed that it may lead to improvements in downstream treatment and, most importantly, improved health outcomes.

“In our real-world, population-based study of adults discharged from the emergency department after evaluation for chest pain, the overall rate of heart attack and death were very low. Non-invasive testing was associated with a small reduction in rates of downstream heart attacks or death. That reduction was driven by high-risk patients,” says Dr. Idan Roifman, lead author on the study, an adjunct scientist at ICES and staff cardiologist at Schulich Heart Centre.

Chest pain is one of the most common reasons people visit Canadian emergency departments, with around 800,000 visits a year.

The study, published in the Journal of the American Heart Association (JAHA), is the first to compare strategies of no-testing to those who undergo any non-invasive diagnostic testing. The researchers found that non-invasive tests like the graded exercise stress test, stress echocardiography (echo), myocardial perfusion imaging or coronary computed tomography angiography (CT or CAT scan) after emergency department discharge may be overused in low and intermediate-risk patients.

More than 370,000 people who went to an emergency department in Ontario from 2010 to 2015 with chest pain, and were discharged home after evaluation were included in the study. The researchers then followed the patients for 30 days to determine if they received a non-invasive test or not. The patients were subsequently followed for one year to measure important clinical outcomes like heart attack or death.

“We found that for patients in our study, getting a non-invasive test meant they were more likely to have follow-ups with both family physicians and cardiologists in addition to further treatment such as angioplasty. However, this increased downstream use led to improved outcomes in the high risk patients only. Only approximately 10 per cent of the patients in our study were classified as high risk. Our study failed to report a significant improvement in outcomes in those who were at low and intermediate risk, which represented approximately 90 per cent of the patients that we studied,” adds Dr. Roifman.

The researchers add that fewer non-invasive tests should be performed on low and intermediate-risk patients and more tests could be performed on high-risk patients like those who have had previous heart conditions, to ensure that the non-invasive testing is optimally used in those patients discharged from the emergency department after evaluation for chest pain.

The study “Clinical effectiveness of cardiac non-invasive diagnostic testing in patients discharged from the emergency department for chest pain,” was published by Journal of the American Heart Association (JAHA).

Author block: Idan Roifman, Lu Han, Maria Koh, Harindra C. Wijeysundera, Peter C Austin, Pamela S. Douglas and Dennis T. Ko.

ICES is an independent, non-profit research institute that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy. In October 2018, the institute formerly known as the Institute for Clinical Evaluative Sciences formally adopted the initialism ICES as its official name. For the latest ICES news, follow us on Twitter: @ICESOntario