Outcomes of patients admitted with limit of blank high-sensitive cardiac troponin T levels versus those with levels under the limit of detection

Abstract

Abstract Background Patients with suspected non-ST-elevation acute coronary syndrome (NSTE-ACS) and high-sensitive cardiac troponin T (hs-cTnT) values below the level of detection (5 ng/L) in a single test have a high negative predictive value for myocardial infarction (MI). Purpose We compared the clinical outcomes and resource utilization of suspected NSTE-ACS patients who were admitted despite hs-cTnT values below the limit of detection (5 ng/L) versus those with values ≤ the limit of blank (3 ng/L). Methods This single center retrospective cohort analysis included 2,081 emergency room (ER) visits for suspected NSTE-ACS that manifested single hs-cTnT value <5 ng/L (limit of detection) - 624 with single hs-cTnT ≤3 ng/L (limit of blank) and 1,457 with single hs-cTnT values >3 ng/L and <5 ng/L, and yet were admitted (Figure 1). Routine quality control and dedicated tests proved a coefficient of variance of <10% for hs-cTnT values <99th percentile (14 ng/L). Results There were no in-hospital or 30-day deaths in both groups. Discharge diagnosis of MI was documented only in the 3–5 ng/L hs-cTnT group – 3 cases (∼0.2%). Median ER stay were 5 and 6 hours for ≤3 ng/L and 3–5 ng/L groups, respectively. Median hospital stay was 3 days for both groups. Coronary angiographies culminating in interventions were documented in 1 case (∼0.2%) and 24 cases (∼1.6%) for ≤3 ng/L and 3–5 ng/L groups, respectively. Conclusion Suspected NSTE-ACS patients with hs-cTnT values ≤ the limit of blank are at very low risk and may not need any further evaluation. Funding Acknowledgement Type of funding sources: None. Figure 1