A Bayesian approach to acute coronary occlusion.

In the STEMI paradigm, the disease (acute coronary occlusion) is defined and named after one element (ST elevation, without regard to the remainder of the QRST) of one imperfect test (the ECG). This leads to delayed reperfusion for patients with acute coronary occlusion whose ECGs don't meet STEMI criteria. In this editorial, we elaborate on the article by Jose Nunes de Alencar Neto about applying Bayesian reasoning to ECG interpretation. The Occlusion MI (OMI) paradigm offers evidencebased advances in ECG interpretation, expert-trained artificial intelligence, and a paradigm shift that incorporates a Bayesian approach to acute coronary occlusion.

Missing occlusions: Quality gaps for ED patients with occlusion MI.

BACKGROUND: ST-elevation Myocardial Infarction (STEMI) guidelines encourage monitoring of false positives (Code STEMI without culprit) but ignore false negatives (non-STEMI with occlusion myocardial infarction [OMI]). We evaluated the hospital course of emergency department (ED) patients with acute coronary syndrome (ACS) using STEMI vs OMI paradigms. METHODS: This retrospective chart review examined all ACS patients admitted through two academic EDs, from June 2021 to May 2022, categorized as 1) OMI (acute culprit lesion with TIMI 0-2 flow, or acute culprit lesion with TIMI 3 flow and peak troponin I >10,000 ng/L; or, if no angiogram, peak troponin >10,000 ng/L with new regional wall motion abnormality), 2) NOMI (Non-OMI, i.e. MI without OMI) or 3) MIRO (MI ruled out: no troponin elevation). Patients were stratified by admission for STEMI. Initial ECGs were reviewed for automated interpretation of "STEMI", and admission/discharge diagnoses were compared. RESULTS: Among 382 patients, there were 141 OMIs, 181 NOMIs, and 60 MIROs. Only 40.4% of OMIs were admitted as STEMI: 60.0% had "STEMI" on ECG, and median door-to-cath time was 103 min (IQR 71-149). But 59.6% of OMIs were not admitted as STEMI: 1.3% had "STEMI" on ECG (p < 0.001) and median door-to-cath time was 1712 min (IQR 1043-3960; p < 0.001). While 13.9% of STEMIs were false positive and had a different discharge diagnosis, 32.0% of Non-STEMIs had OMI but were still discharged as "Non-STEMI." CONCLUSIONS: STEMI criteria miss a majority of OMI, and discharge diagnoses highlight false positive STEMI but never false negative STEMI. The OMI paradigm reveals quality gaps and opportunities for improvement.

Chest Pain, Paced Rhythm, and 2 Missed Indications for Emergent Reperfusion.

This case report describes a 70-year-old patient with intermittent chest pain that developed into constant chest pain, sweating, and shortness of breath.

Kenichi Harumi Plenary Address at Annual Meeting of the International Society of Computers in Electrocardiology: "What Should ECG Deep Learning Focus on? The diagnosis of acute coronary occlusion!"

According to the STEMI paradigm, only patients whose ECGs meet STEMI criteria require immediate reperfusion. This leads to reperfusion delays and significantly increases the mortality for the quarter of "non-STEMI" patients with totally occluded arteries. The Occlusion MI (OMI) paradigm has developed advanced ECG interpretation to identify this high-risk group, including examining the ECG in totality and assessing ST/T changes in proportion to the QRS. If neural networks are only developed based on STEMI databases and to identify STEMI criteria, they will simply reinforce a failed paradigm. But if deep learning is trained to identify OMI it could revolutionize patient care. This article reviews the paradigm shift from STEMI and OMI, and examines the potential and pitfalls of deep learning. This is based on the Kenichi Harumi Plenary Address at the Annual Meeting of the International Society of Computers in Electrocardiology, given by OMI expert Dr. Stephen Smith.

Flattening the other curve: Reducing emergency department STEMI delays during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic has been associated with ST-Elevation Myocardial Infarction (STEMI) reperfusion delays despite reduced emergency department (ED) volumes. However, little is known about ED contributions to these delays. We sought to measure STEMI delays and ED quality benchmarks over the course of the first two waves of the pandemic. STUDY: This study was a multi-centre, retrospective chart review from two urban, academic medical centres. We obtained ED volumes, COVID-19 tests and COVID-19 cases from the hospital databases and ED Code STEMIs with culprit lesions from the cath lab. We measured door-to-ECG (DTE) time and ECG-to-Activation (ETA) time during the phases of the pandemic in our jurisdiction: pre-first wave (Jan-Mar 2020), first wave (Apr-June 2020), post-first wave (July-Nov 2020), and second wave (Dec 2020 to Feb 2021). We calculated median DTE and ETA times and compared them to the 2019 baseline using Wilcox rank-sum test. We calculated the percentages of DTE ≤10 min and of ETA ≤10 min and compared them to baseline using chi-square test. We also utilized Statistical Process Control (SPC) Xbar-R charts to assess for special cause variation. RESULTS: COVID-19 cases began during the pre-wave phase, but there was no change in ED volumes or STEMI quality metrics. During the first wave ED volumes fell by 40%, DTE tripled (10.0 to 29.5 min, p = 0.016), ETA doubled (8.5 to 17.0 min, p = 0.04), and percentages for both DTE ≤10 min and ETA ≤10 min fell by three-quarters (each from more than 50%, to both 12.5%, both p < 0.05). After the first wave all STEMI quality benchmarks returned to baseline and did not significantly change during the second wave. A brief period of special cause variation was noted for DTE during the first wave. CONCLUSIONS: Both DTE and ETA metrics worsened during the first wave of the pandemic, revealing how it negatively impacted the triage and diagnosis of STEMI patients. But these normalized after the first wave and were unaffected by the second wave, indicating that nurses and physicians adapted to the pandemic to maintain STEMI quality of care. DTE and ETA metrics can help EDs identify delays to reperfusion during the pandemic and beyond.

Sharing and Teaching Electrocardiograms to Minimize Infarction (STEMI): reducing diagnostic time for acute coronary occlusion in the emergency department.

BACKGROUND: Limits to ST-Elevation Myocardial Infarction (STEMI) criteria may lead to prolonged diagnostic time for acute coronary occlusion. We aimed to reduce ECG-to-Activation (ETA) time through audit and feedback on STEMI-equivalents and subtle occlusions, without increasing Code STEMIs without culprit lesions. METHODS: This multi-centre, quality improvement initiative reviewed all Code STEMI patients from the emergency department (ED) over a one-year baseline and one-year intervention period. We measured ETA time, from the first ED ECG to the time a Code STEMI was activated. Our intervention strategy involved a grand rounds presentation and an internal website presenting weekly local challenging cases, along with literature on STEMI-equivalents and subtle occlusions. Our outcome measure was ETA time for culprit lesions, our process measure was website views/visits, and our balancing measure was the percentage of Code STEMIs without culprit lesions. RESULTS: There were 51 culprit lesions in the baseline period, and 64 in the intervention period. Median ETA declined from 28.0 min (95% confidence interval [CI] 15.0-45.0) to 8.0 min (95%CI 6.0-15.0). The website garnered 70.4 views/week and 27.7 visitors/week in a group of 80 physicians. There was no change in percentage of Code STEMIs without culprit lesions: 28.2% (95%CI 17.8-38.6) to 20.0% (95%CI 11.2-28.8%). Conclusions Our novel weekly web-based feedback to all emergency physicians was associated with a reduction in ETA time by 20 min, without increasing Code STEMIs without culprit lesions. Local ECG audit and feedback, guided by ETA as a quality metric for acute coronary occlusion, could be replicated in other settings to improve care.

Using ECG-To-Activation Time to Assess Emergency Physicians' Diagnostic Time for Acute Coronary Occlusion.

BACKGROUND: There is no quality metric for emergency physicians' diagnostic time for acute coronary occlusion. OBJECTIVE: We sought to quantify diagnostic time associated with automated interpretation, classic ST-elevation myocardial infarction (STEMI) criteria, STEMI-equivalents, and subtle occlusions, using electrocardiogram (ECG)-to-activation of catheterization laboratory time. METHODS: This multicenter retrospective study reviewed all code STEMI patients from the emergency department (ED) with confirmed culprit lesions from January 2016 to December 2018. We measured door-to-ECG (DTE) time and ECG-to-activation (ETA) time. We examined the first ED ECGs to determine whether automated interpretation labeled "STEMI," and they met classic STEMI criteria, STEMI-equivalents, or rules for subtle occlusion. ECG analysis was performed by two emergency physicians blinded to clinical scenario, automated interpretation, and angiographic outcome. RESULTS: There were 177 code STEMIs with culprit lesions, with a median DTE time of 9.0 min and a median ETA time of 16.0 min. Automated interpretation labeled 55.4% of first ECGs "STEMI" (ETA 6.5 min) and 44.6% not "STEMI" (ETA 66 min, p < 0.0001). Of first ECGs, 63.8% met classic STEMI criteria (ETA 8.0 min), 8.5% had STEMI-equivalents (ETA 32.0 min, p = 0.0026), 16.4% had subtle occlusions (ETA 89.0 min, p = 0.045), and 11.3% had no diagnostic sign of occlusion (ETA 68.0 min, p = 0.20). CONCLUSIONS: STEMI criteria missed more than one-third of occlusions on first ECG, but most had STEMI-equivalents or rules for subtle occlusion. ETA time can serve as a quality metric for emergency physicians to promote new ECG insights and assess quality improvement initiatives.