Suspected myocardial infarction in the emergency department: An evaluation of clinical thresholds for the Beckman Coulter Access hsTnI high-sensitivity cardiac troponin I assay.

OBJECTIVE: The primary objective was to determine rapid rule-out (RRO) criteria for the outcome of myocardial infarction (MI) using the Beckman Coulter Access high-sensitivity cardiac troponin I (hs-cTnI) assay. Secondary objectives were to explore cut-points for rapid rule-in (RRI) and amount of change at 3-h (3-h delta) indicative of MI. METHODS: A retrospective study included ED patients with suspected MI between June and September 2019. hs-cTnI levels were performed at baseline and after 3 h. The performance benchmark for RRO criteria was a negative predictive value (NPV) for MI with a lower 95% confidence limit >99%, and for RRI and 3-h delta cut-points was a positive predictive value (PPV) for MI >70%. Delta calculation required rising hs-cTnI levels, with at least one above the 99th percentile of the upper reference limit. Analyses utilised receiver operating characteristic (ROC) curves and contingency tables. RESULTS: Baseline hs-cTnI levels from 935 patients were available for RRO analyses. Of tested criteria, baseline hs-cTnI <6 ng/L (females) or <11 ng/L (males) plus symptom onset >2 h met the performance benchmark (NPV: 100% [95% confidence interval 99-100]). hs-cTnI levels were available for RRI and 3-h delta analyses from 935 and 52 patients, respectively. A 3-h delta cut-point >35 ng/L met the performance benchmark (PPV: 81% [95% confidence interval 58-95]) but no RRI cut-point did so. CONCLUSIONS: For the Beckman Coulter Access hs-cTnI assay, RRO criteria of baseline hs-cTnI <6 ng/L (females) or <11 ng/L (males) plus symptom onset >2 h met our performance benchmark. A 3-h delta cut-point >35 ng/L met the performance benchmark, but poor precision means further adequately powered research is required.

Potential impact of a novel pathway for suspected myocardial infarction utilising a new high-sensitivity cardiac troponin I assay.

BACKGROUND: High-sensitivity cardiac troponin I (hs-cTnI) assays promise high diagnostic accuracy for myocardial infarction (MI). In an ED where conventional cTnI was in use, we evaluated an assessment pathway using the new Access hsTnI assay. METHODS: This retrospective analysis recruited ED patients with suspected MI between June and September 2019. All patients received routine care with a conventional cTnI assay (AccuTnI +3: limit of detection (LoD) 10 ng/L, 99th centile upper reference limit (URL) 40 ng/L, abnormal elevation cut-point 80 ng/L). Arrival, then 90-minute or 360-minute cTnI levels for low and non-low risk patients, respectively (ED Assessment of Chest pain score) guided diagnosis and disposition which was at treating physician discretion. The same patients had arrival and 90-minute or 180-minute samples drawn for hs-cTnI levels (Access hsTnI: LoD 2 ng/L, 99th centile URL 10 ng/L (females) and 20 ng/L (males); abnormal elevation above the URL and delta >30%). Treating physicians were blinded to the hs-cTnI results. Using the hs-cTnI values, investigators retrospectively assigned likely diagnosis, disposition and likelihood of a 30-day major adverse cardiac event (MACE). Admission was recommended for significantly rising hs-cTnI elevations. The primary objective was to demonstrate an acceptable unexpected 30-day post-discharge MACE rate of <1%. cTnI elevation rates, diagnostic outcomes and ED disposition were also compared between pathways. RESULTS: For the 935 patients, unexpected 30-day post-discharge MACE rates were 0/935 (0%, 95% CI 0% to 0.4%) with the conventional or novel pathway. For the high-sensitivity and conventional assays, respectively, abnormal elevation rates were 29% (95% CI 26% to 32%) and 19% (95% CI 17% to 22%), for MI were 9% (95% CI 8% to 11%) and 8% (95% CI 6% to 10%), and for hospital admission were 42% (95% CI 39% to 45%) and 43% (95% CI 40% to 47%). CONCLUSION: The novel pathway using the Access hsTnI assay has an acceptably low 30-day MACE rate.

Development of a virtual reality clinically oriented temporal bone anatomy module with randomised control study of three-dimensional display technology.

Objective: To investigate the effectiveness of a virtual reality (VR), three-dimensional (3D) clinically orientated temporal bone anatomy module, including an assessment of different display technologies. Methods: A clinically orientated, procedural and interactive anatomy module was generated from a micro-CT of a cadaveric temporal bone. The module was given in three different display technologies; 2D, 3D with monoscopic vision, and 3D with stereoscopic vision. A randomised control trial assessed the knowledge acquisition and attitudes of 47 medical students though a pretutorial and post-tutorial questionnaire. The questionnaire included questions identifying anatomic structures as well as understanding structural relations and clinical relevance. Furthermore, a five-point Likert scale assessed the students' attitudes to the module and alternative learning outcomes, such as interest in otology and preparedness for clinical rotations. Results: As a whole cohort, the total test score improved significantly, with a large effect size (p≤0.005, Cohen's d=1.41). The 23 students who returned the retention questionnaire had a significant improvement in total test score compared with their pretutorial score, with a large effect size (p≤0.005, Cohen's d=0.83). Display technology did not influence the majority of learning outcomes, with the exception of 3D technologies, showing a significantly improvement in understanding of clinical relevance and structural relations (p=0.034). Students preferred 3D technologies for ease of use, perceived effectiveness and willingness to use again. Conclusions: The developed VR temporal bone anatomy tutor was an effective self-directed education tool. 3D technology remains valuable in facilitating spatial learning and superior user satisfaction.

Functional outcome and management pathways for adult patients presenting to an Australian health service with distal radius fracture.

OBJECTIVE: Primarily to determine mid-term functional outcome for patients with distal radius fracture (DRF) and to compare this between operative and conservatively managed patients. Secondarily to examine for differences in age, gender and number of instability factors between management groups. METHODS: Eligible patients (age 18 years or more, closed DRF managed to completion of care within Monash Health), presenting between 1 January and 31 December 2016. Completion of the patient-rated wrist evaluation (PRWE) questionnaire was sought at 6-12 months post-injury. Management was noted (operative or conservative). Age, sex and number of defined instability factors present (dorsal angulation >20°, intra-articular fracture, associated ulna fracture, dorsal comminution, radial shortening >2 mm) are reported and compared between management groups. RESULTS: Of 369 eligible patients, 199 (54%) completed a PRWE. Median age was 60 years (interquartile range [IQR] 45-71), 150 (75%) were women, median number of instability factors present was 2 (IQR 1-4) and 45 (23%) underwent operative management. Difference in PRWE scores between operative and conservatively managed patients was not significant (20 [IQR 7-36] vs 16 [IQR 5-35]). Differences in age and gender between management groups were not significant. Significantly more in the operative group had presence of four or more instability factors (44% [95% confidence interval 30-60] vs 20% [14-27]). CONCLUSION: The mid-term median PRWE score was 18 (IQR 5-36). This was not significantly different between operative and conservatively managed patients. Operation was more likely when four or more instability factors were present.