Are fast track protocols using highly sensitive troponin assays (0-1 h vs 0-3 h algorithms) valid and appropriately recommended by current guidelines for ruling in and ruling out NSTEMI?
The authors challenge recent ESC guidelines, arguing that the 0-1 h hsTn algorithm for NSTEMI rule-in lacks sufficient validation compared to the 0-3 h algorithm and warrants caution.
The introduction of "highly sensitive" cardiac troponin assays (hsTn) has reinforced the evidence that only serial testing incorporated in running algorithms allows a more accurate diagnosis of acute myocardial infarction. In this report, we consider the available evidence supporting the use of fast track protocols for ruling out and ruling in non-ST elevation myocardial infarction (NSTEMI) and compare it with the content of recently released guideline by the European Society of Cardiology, noting some uncomfortable aspects that need urgent clarification and/or revision. Firstly, the guideline drafters have to reconsider the available evidence that does not permit to assign the same class and level of evidence to the very well-validated 0-3 h algorithm and to the 0-1 h algorithm. In agreement with the validity of available data, the limitations of fast track protocols, in particular of the 0-1 h algorithm for NSTEMI rule-in, calls for caution. Secondly, as the current diagnostics guidance by the UK National Institute for Health and Care Excellence recommends, rapid diagnostic protocols should be performed only using well-validated hsTn; recommending the use of an assay before being commercially available is not fair and scientifically sound.
Ferraro et al. (Sun,) studied this question.