Kaiser Permanente develops a more precise way to assess heart attack risk
By Sue Rochman
A risk-assessment tool developed by Kaiser Permanente Northern California researchers provides doctors with a more accurate way to assess how likely it is a patient who comes to the emergency department with chest pain will have or die from a heart attack, stroke, cardiac arrest, or other major heart-related problem within the next 60 days, a new study shows.
“The most commonly used tools that are available gave a binary decision — yes or no — as to whether a patient needed additional evaluation,” said the study’s lead author Dustin G. Mark, MD, an adjunct investigator with the Kaiser Permanente Division of Research and an emergency medicine physician with The Permanente Medical Group. “They perform well in identifying the patients who don’t need further evaluation. But they also put patients in the ‘yes’ group who may not actually need additional tests. We set out to try to improve upon that system by creating gradations of risk that can better guide care.”
The study, published in the Journal of the American Heart Association, compared the new tool called Risk Stratification-Acute Coronary Syndrome (RISTRA-ACS) with several other tools commonly used by emergency medicine physicians to produce heart attack risk scores. RISTRA-ACS generates a score that positions a patient on the spectrum of low-to-high risk, allowing for more personalized care. It is part of a suite of RISTRA tools the Kaiser Permanente Division of Research Clinical Research on Emergency Services & Treatment (CREST) Network are developing for real-time clinical decision support.
Chest pain is the second leading reason people go to the emergency room, behind stomach pain. However, only about 1 in 20 patients actually has a life-threatening heart problem. Doctors use medical tests, their clinical decision-making skills, and risk assessment calculators to determine who can safely go home, who needs additional testing, and who ought to be admitted into the hospital.
The study compared the accuracy and net benefits of the RISTRA-ACS calculator with the HEART (history, electrocardiogram, age, risk factors, and troponin blood test) Pathway, the HEART score, the Emergency Department of Chest pain Accelerated Diagnostic Protocol (EDACS-ADP), physician judgement, and blood tests alone for differentiating the patients who needed no further testing from those at risk of having a heart attack.
The analysis included all patients with chest pain who were seen at 1 of the 13 emergency departments that are part of the CREST Network between January 2018 and December 2019. Before the study started, emergency medicine physicians in these departments were educated about the new calculator, which was accessible to them through the hospital’s electronic medical records. During the study, they received an automated text message about the calculator each time troponin blood test results became available for a patient with chest pain. (When the heart muscle is injured, it releases the protein troponin into the blood stream; a high troponin level is a sign of a heart attack.)
Over the 2-year study, the emergency room physicians used the RISTRA-ACS risk score during their medical assessment for 13,192 patients who met the study criteria. Of these, 3.7% had a heart attack, stroke, cardiac arrest, or other major heart problem during their initial visit or within the next 60 days, and 85% were discharged home directly from the emergency department.
The study found that both the RISTRA-ACS and the HEART pathway risk scores accurately identified very low-risk patients. However, the RISTRA-ACS risk score was found to be better than the HEART score, troponin tests alone, and physician judgement in distinguishing which patients would experience a major heart problem within 60 days. In addition, the RISTRA-ACS tool accurately risk stratified more than 50% of the patients with only a single troponin measurement, whereas the EDACS-ADP and HEART pathway require multiple troponin tests.
“Our new tool outperformed everything else we compared it to,” said Mark. “It allows us to more accurately identify those who need further evaluation. It also allows us to change the messaging and not just say to a patient that your test was negative or positive, but explain that there is a spectrum of disease, and that we can make an informed estimate about where you are on that spectrum. The patient and the clinician can then make a joint decision about whether to pursue additional testing.”
The study’s senior author Mary E. Reed, DrPh, a research scientist at the Division of Research, said the team will continue to study the impact the new risk score has on patients. “This paper says the risk score works and is safe. The next step is to show the effect the risk score has on the decisions doctors make in the emergency department as well as how it affects patient outcomes.”
This project is supported by The Permanente Medical Group Delivery Science and Applied Research Initiative and Physician Researcher Program.
Coauthors include David R. Vinson, MD, and Dana R. Sax, MD, MPH, of the Division of Research and The Permanente Medical Group; Jie Huang, PhD, Judy Shan, BS, and Adina S. Rauchwerger, MPH, of the Division of Research; Mamata V. Kene MD, MPH, Dale M. Cotton, MD, James S. Lin, MD, Sean C. Bouvet, MD, Uli K. Chettipally, MD, MPH, Megan L. Anderson, MD, and Ian D. McLachlan, MD, of The Permanente Medical Group; and Laura E. Simon, BA, of the University of California, San Diego, for the Kaiser Permanente CREST Network Investigators.
About the Kaiser Permanente Division of Research
The Kaiser Permanente Division of Research conducts, publishes and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and society at large. It seeks to understand the determinants of illness and well-being, and to improve the quality and cost-effectiveness of health care. Currently, DOR’s 600-plus staff is working on more than 450 epidemiological and health services research projects. For more information, visit divisionofresearch.kaiserpermanente.org or follow us @KPDOR.