Cost-effectiveness of the transition from conventional to high-sensitivity troponin assay for the investigation and management of suspected acute coronary syndrome in the emergency department

Background: Switching from conventional to high-sensitivity cardiac troponin (hs-cTn) assays with sex-specific reference rates for threshold troponin levels enables detection of smaller amounts of myocardial damage. However, the real-world impact of these assays on patient outcomes and health service costs is poorly understood. We investigated the cost-effectiveness of switching to hs-cTn assays for patients presenting to Australian Emergency Departments (EDs) with suspected acute coronary syndrome (ACS) with a 12-month follow-up period. Methods: Using linked administrative data from 9 tertiary hospitals for patients aged 20 and above who presented to ED with suspected ACS between March 2011 and November 2015, we applied a difference-in-differences methodology to compare costs and major adverse cardiac events between hospitals switching to hs-cTn assays and hospitals continuing to use conventional assays. Results: We identified 179,681 consecutive patients, of whom 87,019 presented during the preperiod and 92,662 the postperiod. Switching to hs-cTn was associated with a reduction in the cost of the index event (-$1,022, 95% CI: -$1,034, -$1,009), a reduction in total costs at 12 months (-$1,373, 95% CI: -$1,387, -$1,360) and a reduction in the percentage of patients experiencing a MACE outcome within 12-months (-0.55%, 95% CI: -0.88%, -0.21%). The reduction in MACE outcomes was larger for female patients (-1.17%, 95% CI: -1.19%, -1.14%) than for all patients and for males. Conclusions: The switch to hs-cTn is highly cost-effective across all patients and for each sex. The reduction in MACE outcomes and costs within 12 months are greater for females than for males.