Abstract
Introduction
Current ESC guidelines have introduced a 0h/1h algorithm for accelerated rule-in or rule-out of acute myocardial infarction (MI) when using assay specific high-sensitive cardiac troponin I (hs-cTnI). Several studies have investigated the diagnostic performance and safety of this approach using different hs-cTnI assays. However, little is known of the diagnostic performance of a 0h/30min algorithm.
Purpose
To evaluate the diagnostic accuracy of early rule-in or rule-out of MI after 30 minutes by applying assay specific hs-cTnI cut-off values from a recently validated 0h/1h algorithm.
Methods
We prospectively enrolled chest pain patients suggestive of MI admitted to the Emergency Department. Patients underwent serial hs-cTnI measurements at admission (0 hour) and after 3 hours according to clinical practice. In addition, hs-cTnI measurements were performed after 30 minutes. The assay specific cut-off values from the 0h/1h algorithm were applied to the 30 minute cohort (figure 1). Final diagnosis was adjudicated independently by two physicians.
Results
In total, 943 patients were included. MI was the final diagnosis in 67 (7.1%) patients. Overall, absolute hs-cTnI values after 30 minutes were significantly higher in the MI group than in the non-MI group (19.2 (Q1:Q3) 2.7–75.3) ng/L versus 0.1 (0.2–0.7) ng/L, p<0.001). When applying the assay-specific hs-cTnI cut-off valuesfor the 0h/1h algorithmto the 30 minute patient cohort, 52.4% of patients were classified as rule-out with a negative predictive value of 100% (95% CI: 99.2–100). In total, 8.5% were classified as rule-in with a positive predictive value of 83.8% (95% CI: 74.2–90.3). Sensitivity was 100% (95% CI: 94.6–100) and specificity was 97.4% (95% CI: 95.7–98.6). Overall, 39.1% were assigned to the observational zone with a 3.5% prevalence of MI.
Conclusions
The use of assay specific hs-cTnI measurement at admission (0h) and 30 min later can be used to safely rule-out MI. This indicates that it might be safe to develop a 0h/30min algorithm and hereby reduce time to diagnosis even further. NCT03634384.
Acknowledgement/Funding
Randers Regional Hospital, A.P Møller Foundation, Boserup Foundation, Korning Foundation, Højmosegård Grant, Siemens Healthcare (TNIH assays), etc.
Acceptable Analytical Variation May Exceed High-Sensitivity Cardiac Troponin I Cutoffs in Early Rule-Out and Rule-In Acute Myocardial Infarction Algorithms