Implementation of more sensitive cardiac troponin T assay in a state-wide health service

Aims: Explore the impact of deploying high-sensitivity (hs) cardiac troponin T (cTnT) assay across a state-wide health service. Methods and results: Presentations to emergency departments of six tertiary hospitals between January 2008 and August 2019 were included; standard cTnT assay was superseded by hs-cTnT in June 2011 without changing the reference range (>= 30 ng/L reported as elevated), despite cTnT level of 30 ng/L being equivalent to similar to 44 ng/L with hs-cTnT. Clinical outcomes were captured using state-wide linked health records. Interrupted time series analyses were used adjusted for seasonality and multiple co-morbidities using propensity score matching allowing for correlation within hospitals. In total, 614,847 presentations had >= 1 troponin measurement. Clinical ordering of troponin decreased throughout the study with no increase in elevated measurements amongst those tested with hs-cTnT. Small but statistically significant changes in index myocardial infarction (MI) diagnosis (-0.36%/year, 95%CI [confidence interval]:-0.48, -0.24,p < 0.001) and invasive coronary angiography (0.12%/year, 95%CI:0, 0.24,p = 0.02) were seen, with no impact on death/MI at 30 days or 3-year survival in episodes of care (EOCs) with elevated cTnT after hs-cTnT implementation. Length of stay (LOS) was shorter among those with an elevated hs-cTnT (-4.44 h/year, 95%CI:-5.27, -3.60, p < 0.001). Non-elevated cTnT EOCs demonstrated shorter total LOS and improved 3-year survival (adjusted hazard ratio:0.90, 95%CI:0.83, 0.97,p = 0.008) although death/MI at 30 days was unchanged using hs-cTnT. Conclusion: Widespread implementation of hs-cTnT without altering clinical thresholds reported to clinicians provided significantly shorter LOS without a clinically significant impact on clinical outcomes. A safer cohort with non-elevated cTnT was identified by hs-cTnT compared to the standard cTnT assay.

Automated summary

The study found that the widespread implementation of high-sensitivity cardiac troponin T (hs-cTnT) assay in medical services can significantly reduce patients' length of stay without causing a significant impact on clinical outcomes. Compared to the standard testing method, hs-cTnT can more accurately identify a safer cohort with non-elevated cTnT.