Comparison of fourteen rule-out strategies for acute myocardial infarction.

Background: The clinical availability of high-sensitivity cardiac troponin (hs-cTn) has enabled the development of several innovative strategies for the rapid rule-out of acute myocardial infarction (AMI). Due to the lack of direct comparisons, selection of the best strategy for clinical practice is challenging.

Methods: In a prospective international multicenter diagnostic study enrolling 3696 patients presenting with suspected AMI to the emergency department, we compared the safety and efficacy of 14 different hs-cTn-based strategies: hs-cTn concentrations below the limit of detection (LoD), dual-marker combining hs-cTn with copeptin, ESC 0 h/1 h-algorithm, 0 h/2 h-algorithm, 2 h-ADP-algorithm, NICE-algorithm, and ESC 0 h/3 h-algorithm, each using either hs-cTnT or hs-cTnI. The final diagnosis of AMI was adjudicated by two independent cardiologists using all available clinical information including cardiac imaging and serial hs-cTn concentrations.

Results: AMI was the final diagnosis in 16% of patients. Using hs-cTnT, safety quantified by the negative predictive value (NPV) and sensitivity was very high (99.8-100% and 99.5-100%) and comparable for all strategies, except the dual-marker approach (NPV 98.7%, sensitivity 96.7%). Similarly, using hs-cTnI, safety quantified by the NPV and sensitivity was very high (99.7-100% and 98.9-100%) and comparable for all strategies, except the dual-marker approach (NPV 96.9%, sensitivity 90.4%) and the NICE-algorithm (NPV 99.1%, sensitivity 94.7%). Efficacy, quantified by the percentage of patients eligible for rule-out, differed markedly, and was lowest for LoD-algorithm (15.7-26.8%).

Conclusion: All rapid rule-out algorithms, except the dual-marker strategy and the NICE-algorithm using hs-cTnI, favorably combine safety and efficacy, and can be considered for routine clinical practice.

Clinical Trial Registration: NCT00470587, http://clinicaltrials.gov/show/NCT00470587.