Abstract
Gimenez MR, Twerenbold R, Jaeger C, et al.
Am J Med 2015; 128: 861–870.
Suspected acute myocardial infarction (MI) still presents a significant diagnostic problem in the emergency department. Delays in diagnosis can increase morbidity and mortality or lead to unnecessary further investigation. Cardiac troponin (cTn) measurement has enabled more effective triage of patients, and recent high-sensitivity cTn (hs-cTn) assays allow measurement of very low levels if cTn with greater precision.
This study investigated the use of hs-cTnI at presentation and 1 h to produce an algorithm that could triage patients into MI ‘rule-in’, ‘rule-out’, or ‘observe’ groups. Of 1811 patients included, half were randomly selected as a derivation cohort in which the algorithm was developed, and the remaining half were assigned as a validation cohort. The algorithm was based on baseline and absolute change of hs-cTnI at 1 h.
The algorithm in the validation cohort classified 50.5% of patients as ‘rule-out’, 19% as ‘rule-in’ and 30.5% as ‘observe’, allowing more rapid triage than that by current guidance. The authors suggest that the negative and positive predictive values determined are higher than the current algorithms in clinical use. The use of such hs-cTnI algorithms in other clinical settings requires investigation, and validation of other hs-cTnI assays is necessary. However, this study indicates that earlier diagnosis of suspected MI is indeed feasible.