Thread by @yadersandoval

1/ See below summary/thread of the background & rationale and other insights from our study and future directions re hs #troponin

2/ Hs #troponin assays have been clinically used outside the US since 2010-11. The 1st of these assays received FDA 510k clearance until 2017 bit.ly/2TUAXEa. Limited US-based data exists on real-life clinical hs #troponin use.

3/ European data from the APACE @CRIBasel group bit.ly/3vL9iTn showed an improved MI rule-out process using hs-assays, and that the implementation of hs assays was associated w/ ⬇️ in ED LOS & stress testing and no adverse impact on downstream resource utilization.

4/ Questions & concerns on US implementation of hs #troponin assays existed, however, given cardiac biomarkers are often used more broadly in the US, i.e. frequent biomarker use in pts. without chest pain bit.ly/3j4Bk9B, and the potential for downstream ⬆️ resource use

5/ In this context the MCHS study goals were mainly to assess the impact of transitioning from 4th to 5th Gen cTnT on the incidence of myocardial injury and MI diagnoses using the 4th UDMI and resource utilization @iam_olatunde @LauraDemichieli @JonathanKnottMD

6/ This observational study involved consecutive encounters of adult patients presenting to the ED with at least one cTnT measurement and addressed the transition from 4th cTnT (6m pre) to 5th Gen cTnT (6m post).

7/ The transition involved the shift from an overall 99th percentile URL (cTnT<0.01 ng/mL) to sex-specific 99th percentile URLs (hs-cTnT F 10 M1 15 ng/L). Most normality studies bit.ly/3qwu3Bv show that men have higher 99th URLs than women bit.ly/35HykIH

8/ Re diagnoses: 32%⬆️ in the proportion of pts. w/ ≥1 cTnT ⬆️>99th percentile URL following hs-cTnT implementation. Almost 50% during the post-implementation period had ⬆️ >99th percentile URL. Following 4UDMI: marked ⬆️in myocardial injury & acute MI, in particular type 2 MI.

9/ Resource use: except for a small ⬆️in coronary angiography, there were no significant downstream increases. There was an overall small ⬇️ LOS & ⬇️ stress tests. Among hs-cTnT<URL, there was marked ⬆️ in ED discharges (60% vs. 74%), as well echocardiography & stress testing⬇️

10/ An important observation from our study is re sex differences in diagnoses using 4th Gen cTnT overall 99th URL vs. 5th Gen cTnT sex-specific 99th URLs. Women were less likely to be diagnosed using 4th Gen cTnT w/ overall 99th URL, not 5th Gen cTnT with sex-specific 99th URLs.

11/ Our findings complement the work from @anoopshah17 @HighSTEACS et al who demonstrated that the use of a hs-cTnI assay with sex-specific 99th percentiles improved MI diagnosis in women bit.ly/3qj5IyR

12/ 4UDMI recommends sex-specific 99th URLs using hs-assays and normality studies show clear differences between men/women. CODE-MI RCT bit.ly/3d6fS0j is evaluating such within a multicenter, stepped-wedge RCT bit.ly/35HG9Ov @CodeMICanada

13/ Critical to place our findings within context that there was multidisciplinary collaboration, preparation, & extensive educational efforts (in-person/online lectures, dissemination of forms, peer-reviewed material, pocket cards, slide presentations, podcasts, etc.)

14/ Study addressed cTnT-to-hs-cTnT. Numerous cTn assays/manufacturers exist. Impact upon hs implementation appears influenced by pre-implementation assay. Several cTnI to hs-cTnI comparisons have not shown ⬆️ in cTn>URL w/ hs-cTnI bit.ly/35JGgc6 bit.ly/3j4IV89

End/ Kudos to our entire research team that made incredible efforts to make these analyses and publication possible jacc.org/doi/10.1016/j.… @JACCJournals ! @iam_olatunde @LauraDemichieli @JonathanKnottMD