HiSTORIC: Troponin I-based risk stratification safely identifies low-risk patients
PARIS — An early rule-out pathway using high-sensitivity cardiac troponin I was able to safely and effectively identify MI in patients with suspected ACS, according to data from the HiSTORIC trial presented at the European Society of Cardiology Congress.
“Adoption of this approach will have major benefits for both patients and health care providers,” Nicholas L. Mills, MD, chair of cardiology, Butler BHF senior clinical research fellow and consultant cardiologist at The University of Edinburgh and principal investigator of the HiSTORIC trial, said during a press conference.
Researchers analyzed data from 32,837 patients (mean age, 61 years; 53% men) who presented to EDs in Scotland with suspected ACS between June 10, 2013 and March 3, 2016. The performance of high-sensitivity cardiac troponin I (Architect Stat, Abbott) was evaluated in patients without myocardial injury at presentation. In the standard care arm, cardiac troponin tests were performed at presentation and at 6 hours or 12 hours after symptom onset.
“The early rule-out pathway incorporates a single high-sensitivity cardiac troponin concentration at presentation,” Mills said during the press conference. “Unlike the guideline approach, we use a separate threshold to risk stratify and to diagnose patients.”
Patients were considered low risk if they had a high-sensitivity cardiac troponin I level less than 5 ng/L, intermediate risk if they had 5 ng/L to the 99th centile and high-risk if they had levels greater than the sex-specific 99th centile.
The primary safety outcome was type 1 or type 4b MI at index presentation, or subsequent type 1 or type 4b MI or cardiac death within 30 days of the initial presentation. The secondary safety outcome was defined as cardiac death or subsequent type 1 or 4b MI at 12 months.
The use of the early rule-out pathway reduced the length of stay by 3.3 hours compared with the standard care pathway. This also increased ED discharge by 57%.
“Overall, three-quarters of the patients were triaged to outpatient assessment within the implementation phase of the trial,” Mills said during the press conference.
Researchers were unable to conclude noninferiority at a margin of 0.5% at 30 days (adjusted risk difference, 0.02% to 0.7%) with regards to the primary safety endpoint of MI or cardiac death. However, there was no evidence of adverse cardiac events at 1 year (adjusted OR = 1.02; 95% CI, 0.74-1.4).
“We were able to conclude that discharging more patients from hospital was not associated with adverse outcomes,” Mills said during the press conference.
This study has the potential to help shift the clinician’s focus on who should receive immediate care.
“This helps clinicians to focus on the highest-risk patients,” Mills said during the Q&A portion of the press conference. “There are a lot of practical reasons why this is the way we treat our patients with acute chest pain. It is the most common presentation to hospital worldwide, with 20 million presentations in the U.S. alone every year. If we can make an evaluation that is safe with a single test on presentation to hospital, avoiding hospital admission and all the downstream investigation..., then the cost savings of this single test when used effectively could be absolutely enormous.” – by Darlene Dobkowski
Mills NL, et al. Hot Line 2. Presented at: European Society of Cardiology Congress; Aug. 31-Sept. 4, 2019; Paris.
Disclosures: The trial was funded by the British Heart Foundation. Mills reports he has research contracts with Abbott Diagnostics and Siemens Healthineers.
Editor's Note: This article was modified on Sept. 2, 2019 to reflect an update to the data.