Objectives To estimate the cost-effectiveness of delayed troponin testing for myocardial infarction compared with troponin testing at presentation.

Design Decision analysis modelling of cost-effectiveness using secondary data sources.

Setting Acute hospitals in the UK.

Population Patients attending hospital with suspected myocardial infarction but a normal or non-diagnostic ECG and no major comorbidities requiring admission.

Interventions Delayed troponin testing (10 h after symptom onset) compared with standard and high-sensitivity troponin testing at presentation and no testing. Sensitivity analysis evaluated high-sensitivity troponin testing 3 h after initial assessment.

Main outcome measures The incremental cost per quality-adjusted life year (QALY) gained by each strategy, compared with the next most effective alternative, and the probability of each strategy being cost-effective at varying willingness-to-pay per QALY gained.

Results In all scenarios tested, presentation high-sensitivity troponin testing was the most effective strategy with an incremental cost-effectiveness ratio below the £20 000/QALY threshold. 10 h troponin testing was only likely to be cost-effective if a discharge decision could be made as soon as a negative result was available and the £30 000/QALY threshold was used, or if a lower sensitivity estimate for presentation high-sensitivity troponin was assumed. Sensitivity analysis showed that including high-sensitivity troponin testing at presentation and 3 h in the analysis makes this the most cost-effective strategy.

Conclusions Delayed troponin testing is unlikely to be cost-effective compared with high-sensitivity troponin testing at presentation in most scenarios. Current NICE chest pain guidelines do not promote cost-effective care.