0 h/1 h or 0 h/2 h rule-out and rule-in algorithms
Step1: Input the hs-cTn value (ng/L)
0/1 h hs-cTn
0/2 h hs-cTn
Select the assays
0/1 h hs-cTn
Very low initial hs-cTn
OR
Low initial hs-cTn and
no increase in 1h hs-cTn
Rule-out
Patients who do not meet the criteria for either of the other two pathways
Observe
High initial hs-cTn
OR
Increase in 1 h hs-Tn
Rule-in
0/2 h hs-cTn
Very low initial hs-cTn
OR
Low initial hs-cTn and
no increase in 2h hs-cTn
Rule-out
Patients who do not meet the criteria for either of the other two pathways
Observe
High initial hs-cTn
OR
Increase in 2 h hs-Tn
Rule-in
Assay specific cut-off levels in ng/L within the 0 h/1 h and 0 h/2 h algorithms

The table above is sourced from the 2023 ESC Guidelines for the management of acute coronary syndromes. For more detailed information, you can access the complete information at the following link: [2023 ESC Guidelines for the management of acute coronary syndromes Supplementary data]
How it work

References
Byrne RA, Rossello X, Coughlan JJ, Barbato E, Berry C, Chieffo A, Claeys MJ, Dan GA, Dweck MR, Galbraith M, Gilard M, Hinterbuchner L, Jankowska EA, Jüni P, Kimura T, Kunadian V, Leosdottir M, Lorusso R, Pedretti RFE, Rigopoulos AG, Rubini Gimenez M, Thiele H, Vranckx P, Wassmann S, Wenger NK, Ibanez B; ESC Scientific Document Group. 2023 ESC Guidelines for the management of acute coronary syndromes. Eur Heart J. 2023 Oct 12;44(38):3720-3826. doi: 10.1093/eurheartj/ehad191. Erratum in: Eur Heart J. 2024 Apr 1;45(13):1145. doi: 10.1093/eurheartj/ehad870. PMID: 37622654.