Patients with known coronary artery disease who are ruled out for acute myocardial infarction using a high sensitivity troponin T 0/1-hour algorithm have increased 30-day major adverse cardiac events
Authors: Nowak R M , O'Neill J C , Ashburn N P , Snavely A C , Paradee B E , Allen B R , Christenson R H , Mumma B E , Madsen T , Stopyra J P , Mahler S A 
Published: October 2022

Abstract

Background
The European Society of Cardiology (ESC) 0/1-hour high sensitivity troponin (hs-cTn) algorithm is widely used in the evaluation of patients presenting to the Emergency Department (ED) with symptoms suspicious for non ST-segment elevation myocardial infarction (NSTEMI). There is limited data available for the use of this algorithm comparing NSTEMI rule-out rates and 30-day adverse outcomes in patients with and without known coronary artery disease (CA), defined as prior myocardial infarction [MI], coronary revascularization, or ≥70% coronary stenosis.

Purpose
The objective of this secondary analysis of the STOP-CP (High Sensitivity Cardiac Troponin T to Optimize Chest Pain Risk Stratification) United States (US) multicenter study was to compare the ESC 0/1-hour algorithm for rapid NSTEMI rule-out and 30-day adverse outcomes in patients with and without known CAD.

Methods
Patients (≥21 years old) presenting to the (ED) with symptoms suggestive of NSTEMI were enrolled (1/25/2017–9/6/2018) at 8 US medical centers. The ESC hs-cTnT 0/1-hour hs-cTnT algorithm was used to stratify patients into rule-out, observe, and rule-in zones. Algorithm performance for 30-day adverse outcomes was analyzed in patients with or without known CAD. Major adverse cardiovascular events (MACE) consisted of cardiac death, MI, or coronary revascularization. Fisher's exact tests were used to compare NSTEMI rule-out and 30-day MACE rates in patients with and without known CAD. Negative likelihood ratios (NLR) with a 95% confidence interval (CI) were calculated for 30-day MACE.

Results
Overall 1430 patients were enrolled. Of these 31.4% (449/1430) had known CAD while 14.2% (203 /1430) experienced 30-day MACE. Using the ESC 0/1-hour hs-cTnT algorithm 39.6% (178/449) of patients with known CAD were placed in the rule-out zone compared to 66.1% (648/981) without CAD (p&lt;0.0001). Of patients with known CAD 23.2% (104/449) had 30-day MACE compared to 10.1% (99/981) of those without known CAD (p&lt;0.0001). Additionally, amongst those patients placed in the rule-out zone, 30-day MACE occurred in 7.9% (14/178) of individuals with known CAD and 1.4% (9/648) of those without known CAD (p&lt;0.0001). NLR for 30-day MACE was 0.28 (95% CI 0.17–0.47) in patients with known CAD and 0.13 (95% CI 0.07–0.23) in those without CAD.

Conclusions
In the multicenter US STOP-CP study patients with known CAD were less often rapidly ruled out for NSTEMI and had higher 30-day MACE rates than those without known CAD. Patients with known CAD who were rapidly ruled out for NSTEMI had a higher 30-day MACE rate compared to those without known CAD. Our analysis suggests that patients with known CAD require further cardiac reevaluations whether they are ruled out for NSTEMI by the ESC 0/1 hour hs-cTnT algorithm or not.

Funding Acknowledgement
Type of funding sources: Private company. Main funding source(s): Roche, Basel, Switzerland