Utility of Serial Troponin Testing for Emergency Department Patients with Syncope

Utility of Serial Troponin Testing for Emergency Department Patients with Syncope

Authors: Cameron W Leafloor, Andrew D McRae, Eric Mercier, Justin W Yan, Paul Huang, Muhammad Mukarram, Brian H Rowe, Aline C Ishimwe, Mona Hegdekar, Marco L A Sivilotti, Monica Taljaard, Marie-Joe Nemnom, Venkatesh Thiruganasambandamoorthy

Published in: CJEM, 2024

Conclusions: The initial troponin measurement was found to be sufficient for detecting serious adverse events and for in-ED risk stratification in patients presenting with syncope. Serial troponin testing did not improve diagnostic yield or prognostication and should be reserved for patients with ongoing symptoms or ECG findings indicative of cardiac ischemia.

Methods: This study is a secondary analysis of data from two prospective studies designed to develop the Canadian Syncope Risk Score. The study included adults aged 16 years and older who presented with syncope. Data collected included patient characteristics, vital signs, physician diagnostic impression, electrocardiogram (ECG) findings, troponin results, and 30-day serious adverse events. The primary outcome was the detection of a serious adverse event within 30 days of ED disposition. The secondary outcome compared ED length of stay between patients with single versus serial troponin measurements.

Results: A total of 4,996 patients were included in the analysis, with a mean age of 64.5 years, and 52.2% were male. Among these, 4,397 patients (89.8%) had a single troponin measurement, while 499 patients (10.2%) had serial troponin measurements. Serious adverse events occurred in 5.3% of patients with a single troponin measurement in the ED and in 4.6% after ED disposition. For those with serial troponin measurements, 7.8% had serious adverse events in the ED, and 12.0% after ED disposition. Only 10 patients (2.0%) with serial measurements had a rise from below to above the 99th percentile threshold, and only four of these patients (0.8%) suffered a serious adverse event, including two with arrhythmias, one with ACS, and one with respiratory failure. Serial testing resulted in risk reclassification for nine patients (1.8%), but none of these patients experienced a 30-day serious adverse event. The median ED length of stay was significantly longer for patients with serial troponin testing compared to those with a single measurement (5.6 hours vs. 3.8 hours, p < 0.001).