Diagnosis performance of high sensitivity troponin assay in out-of-hospital cardiac arrest patients

Purpose: Early identification of the cause of out-of-hospital cardiac arrest (OHCA) remains a challenge. Our aim was to determine whether high-sensitivity cardiac troponin T (HsTnT) was useful to diagnose a recent coronary artery occlusion as the cause of OHCA.

Methods: Retrospective study including OHCA patients evaluated by systematic coronary angiogram at hospital admission. HsTnT was assessed at ICU admission. Predictive factors of a recent coronary occlusion were identified by logistic regression. Net reclassification improvement (NRI) was calculated to estimate the potential enhancement of prediction with HsTnT.

Results: During the 5 year study period, 272 patients (median age 60 y, 76.5% men) were included, and a culprit coronary occlusion was found in 133 (48.9%). The optimum HsTnT cut-off to predict a recent coronary occlusion was 575 ng/l (sensitivity 65.4%, specificity 65.5%). In multivariate analysis, current smoking (OR 3.2 95%, 95%CI 1.62-6.33), time from collapse to BLS<3 min (OR 2.11, 95%CI 1.10-4.05), initial shockable rhythm (OR 5.29, 95%CI 2.06-13.62), ST-segment elevation (OR 2.44, 95%CI 1.18-5.03), post-resuscitation shock onset (OR 2.03, 95%CI 1.01-4.07) and HsTnT≥575 ng/l (OR 2.22, 95%CI 1.16-4.27) were associated with the presence of a recent coronary occlusion. Nevertheless, adding HsTnT to established risk factors of recent coronary occlusion identified above provided a non-significant NRI of -0.43%.

Conclusions: Admission HsTnT is increased after OHCA and is an independent factor of a recent coronary occlusion. However, HsTnT does not seem to be a strong enough diagnostic tool to select candidates for emergent coronary angiogram in OHCA survivors.