Single-Molecule hsTnI and Short-Term Risk in Stable Patients With Chest Pain.
BACKGROUND
Evaluation of stable symptomatic outpatients with suspected coronary artery disease (CAD) may be challenging because they have a wide range of cardiovascular risk. The role of troponin testing to assist clinical decision making in this setting is unexplored.


OBJECTIVES
This study sought to evaluate the prognostic meaning of single-molecule counting high-sensitivity troponin I (hsTnI) (normal range <6 ng/l) among outpatients with stable chest symptoms and suspected CAD.


METHODS
Participants with available blood samples in PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) were studied, and hsTnI results were analyzed relative to the primary outcome of death, acute myocardial infarction (MI), or hospitalization for unstable angina by 1 year. The secondary outcome was the composite of cardiovascular death or acute MI.


RESULTS
The study sample consisted of 4,021 participants; 98.6% had measurable hsTnI concentrations. The median hsTnI value was 1.6 ng/l. In upper hsTnI quartiles, patients had higher-risk clinical profiles. Higher hsTnI concentrations were associated with greater event probabilities for death, acute MI, or hospitalization for unstable angina. In multivariable models, hsTnI concentrations independently predicted death, acute MI, or hospitalization for unstable angina (hazard ratio: 1.54 per increase in log-hsTnI interquartile range; p < 0.001) and cardiovascular death or acute MI (hazard ratio: 1.52 per increase in log-hsTnI interquartile range; p < 0.001) and were particularly associated with near-term events, compared with longer follow-up.


CONCLUSIONS
In symptomatic outpatients with suspected CAD, higher concentrations of hsTnI within the normal range were associated with heightened near-term risk for death, acute MI, or hospitalization. (Prospective Multicenter Imaging Study for Evaluation of Chest Pain [PROMISE]; NCT01174550).
['Januzzi|James L|JL|', 'Suchindran|Sunil|S|', 'Hoffmann|Udo|U|', 'Patel|Manesh R|MR|', 'Ferencik|Maros|M|', 'Coles|Adrian|A|', 'Tardif|Jean-Claude|JC|', 'Ginsburg|Geoffrey S|GS|', 'Douglas|Pamela S|PS|', '|||']
D000368:Aged D060050:Angina, Stable D015415:Biomarkers D005260:Female D006801:Humans D008297:Male D008875:Middle Aged D009656:North America D011446:Prospective Studies D019210:Troponin I
chest pain troponin stable angina