MI probability, outcomes may be predicted with high-sensitivity troponin
A risk assessment tool that incorporated high-sensitivity troponin I or troponin T concentrations determined which patients had an MI when presenting with symptoms at the ED in addition to outcomes at 30 days, according to a study published in The New England Journal of Medicine.
“The COMPASS-MI approach provides risk probabilities for myocardial infarction using a wide range of cutoff combinations of high-sensitivity troponin I or T concentrations, as well as thresholds that are based on either early or late serial sampling,” Johannes T. Neumann, MD, of the University Heart Center Hamburg in Germany, and colleagues wrote.
Researchers analyzed data from 22,651 patients (median age, 63 years; 62% men) from 15 international cohorts who presented to the ED with symptoms that were suggestive of MI. Patients were in the derivation data set (n = 9,604) or the validation data set (n = 13,047).
High-sensitivity troponin I and high-sensitivity troponin T were measured at ED presentation and after early (> 45 minutes to 120 minutes) or late serial sampling (> 120 minutes to 210 minutes) to identify patients who were at low or high risk for MI.
The short-term prognostic endpoint was a composite of all-cause death or subsequent MI at 30 days. The long-term prognostic endpoint was a composite of all-cause death or subsequent MI at 1 year and 2 years.
Of the patients in the study, 15.3% were diagnosed with MI.
The risk assessment tool had a high negative predictive value for MI. Patients who were at low risk for MI typically had very low concentrations of high-sensitivity troponin I or high-sensitivity troponin T at presentation and small absolute changes on serial sampling.
Patients who had high-sensitivity troponin I concentrations less than 6 ng/L when presenting with symptoms at the ED and an absolute change of less than 4 ng/L after 45 to 120 minutes had a negative predictive value for MI of 99.5% (95% CI, 99.2-99.7). The risk for MI or death at 30 days in these patients was 0.2% (95% CI, 0.1-0.4). Based on this, 56.5% of the acute study population would be considered low risk (95% CI, 55.4-57.6).
Results were confirmed by the external validation data set.
“The assignment of patients to the low-risk category may allow for the discharge of patients after other life-threatening causes of chest pain have been ruled out,” Neumann and colleagues wrote. “Patients assigned to the high-risk category have a high prevalence of myocardial infarction and a high risk of death. Therefore, the majority of these patients are candidates for early invasive strategies. It would be important for all of the remaining patients (those fulfilling neither the low-risk nor high-risk criteria) to undergo detailed clinical evaluation, monitoring, further diagnostic testing and invasive strategies as appropriate.” – by Darlene Dobkowski
Disclosures: High-sensitivity troponin I and high-sensitivity troponin T assays used in the study were partially donated by Roche and Abbott. Neumann reports he received grants from the German Heart Foundation/German Foundation of Heart Research and Else Kröner Fresenius Stiftung and personal fees from Abbott Diagnostics and Siemens. Please see the study for all other authors’ relevant financial disclosures.