Reliable exclusion of acute coronary syndrome among hospitalized patients with elevated troponin.

ABSTRACT

BACKGROUND: Elevated cardiac troponin I (cTnI) occurs in acute coronary syndrome (ACS) as well as various scenarios not associated with ACS. HYPOTHESIS: Simple clinical criteria can reliably exclude ACS among hospitalized patients with elevated cTnI. METHODS: Records for patients hospitalized from January to April 2011 with elevated cTnI (>0.29 ng/dL) and an available echocardiogram were retrospectively reviewed. Patients with ST-segment elevation myocardial infarction were excluded. Based on available clinical data, patients were classified as having ACS or elevation of cTnI unrelated to ACS (non-ACS). Median follow-up was 365 days. RESULTS: Of 265 records meeting inclusion criteria, 82 (31%) had ACS and 183 (69%) had non-ACS. In multivariable analysis, odds ratios for non-ACS were 7.6 (95% confidence interval [CI] 3.8-15.3) for peak cTnI <2 ng/dL, 6.3 (95% CI 3.1-13.0) for absent wall-motion abnormality, and 4.4 (95% CI 2.2-8.6) for no prior coronary artery disease history. The area under the receiver operating curve for amodel using these 3 variables was 0.86, with a 98% negative predictive value for excluding ACS. Patients who met these 3 criteria had no ACS-related deaths over 1-year follow-up. CONCLUSIONS: Hospitalized patients with peak Tn level<2 ng/dL, no prior history of coronary artery disease, and no new echocardiographic wall-motion abnormality appear to have a very low likelihood of ACS. Prospective validation of these results is needed to determine whether additional diagnostic testing could be safely avoided in hospitalized patients meeting these simple clinical criteria.