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.

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.

Electrocardiographic Diagnosis of Acute Coronary Occlusion Myocardial Infarction in Ventricular Paced Rhythm Using the Modified Sgarbossa Criteria.

STUDY OBJECTIVE: Ventricular paced rhythm is thought to obscure the electrocardiographic diagnosis of acute coronary occlusion myocardial infarction. Our primary aim was to compare the sensitivity of the modified Sgarbossa criteria (MSC) to that of the original Sgarbossa criteria for the diagnosis of occlusion myocardial infarction in patients with ventricular paced rhythm. METHODS: In this retrospective case-control investigation, we studied adult patients with ventricular paced rhythm and symptoms of acute coronary syndrome who presented in an emergency manner to 16 international cardiac referral centers between January 2008 and January 2018. The occlusion myocardial infarction group was defined angiographically as thrombolysis in myocardial infarction grade 0 to 1 flow or angiographic evidence of coronary thrombosis and peak cardiac troponin I ≥10.0 ng/mL or troponin T ≥1.0 ng/mL. There were 2 control groups: the "non-occlusion myocardial infarction-angio" group consisted of patients who underwent coronary angiography for presumed type I myocardial infarction but did not meet the definition of occlusion myocardial infarction; the "no occlusion myocardial infarction" control group consisted of randomly selected emergency department patients without occlusion myocardial infarction. RESULTS: There were 59 occlusion myocardial infarction, 90 non-occlusion myocardial infarction-angio, and 102 no occlusion myocardial infarction subjects (mean age, 72.0 years; 168 [66.9%] men). For the diagnosis of occlusion myocardial infarction, the MSC were more sensitive than the original Sgarbossa criteria (sensitivity 81% [95% confidence interval [CI] 69 to 90] versus 56% [95% CI 42 to 69]). Adding concordant ST-depression in V4 to V6 to the MSC yielded 86% (95% CI 75 to 94) sensitivity. For the no occlusion myocardial infarction control group of ED patients, additional test characteristics of MSC and original Sgarbossa criteria, respectively, were as follows: specificity 96% (95% CI 90 to 99) versus 97% (95% CI 92 to 99); negative likelihood ratio (LR) 0.19 (95% CI 0.11 to 0.33) versus 0.45 (95% CI 0.34 to 0.65); and positive LR 21 (95% CI 7.9 to 55) versus 19 (95% CI 6.1 to 59). For the non-occlusion myocardial infarction-angio control group, additional test characteristics of MSC and original Sgarbossa criteria, respectively, were as follows: specificity 84% (95% CI 76 to 91) versus 90% (95% CI 82 to 95); negative LR 0.22 (95% CI 0.13 to 0.38) versus 0.49 (95% CI 0.35 to 0.66); and positive LR 5.2 (95% CI 3.2 to 8.6) versus 5.6 (95% CI 2.9 to 11). CONCLUSION: For the diagnosis of occlusion myocardial infarction in the presence of ventricular paced rhythm, the MSC were more sensitive than the original Sgarbossa criteria; specificity was high for both rules. The MSC may contribute to clinical decisionmaking for patients with ventricular paced rhythm.

Post-arrest wide complex rhythm: What is the cause of death?

A 72-year-old man presented to the ED following witnessed cardiac arrest. After return of spontaneous circulation, an ECG was performed which demonstrated a wide complex rhythm with "shark fin" morphology. With careful examination it is possible to identify the J point and determine that the electrocardiogram (ECG) findings actually represent massive ST-elevation indicative of occlusion myocardial infarction (OMI). Initial troponin was undetectable. The patient underwent emergent cardiac catheterization and had a 100% proximal LAD occlusion that was successfully stented. The patient was discharged home neurologically intact several days later. This case highlights the importance of careful ECG interpretation and the limitations of troponin assays in the evaluation of acute coronary syndrome. Most importantly, we demonstrate how to evaluate for ST elevation in the context of a widened QRS complex.

Comparison of the ST-Elevation Myocardial Infarction (STEMI) vs. NSTEMI and Occlusion MI (OMI) vs. NOMI Paradigms of Acute MI.

BACKGROUND: The current ST-elevation myocardial infarction (STEMI) vs. non-STEMI (NSTEMI) paradigm prevents some NSTEMI patients with acute coronary occlusion from receiving emergent reperfusion, in spite of their known increased mortality compared with NSTEMI without occlusion. We have proposed a new paradigm known as occlusion MI vs. nonocclusion MI (OMI vs. NOMI). OBJECTIVE: We aimed to compare the two paradigms within a single population. We hypothesized that STEMI(-) OMI would have characteristics similar to STEMI(+) OMI but longer time to catheterization. METHODS: We performed a retrospective review of a prospectively collected acute coronary syndrome population. OMI was defined as an acute culprit and either TIMI 0-2 flow or TIMI 3 flow plus peak troponin T > 1.0 ng/mL. We collected electrocardiograms, demographic characteristics, laboratory results, angiographic data, and outcomes. RESULTS: Among 467 patients, there were 108 OMIs, with only 60% (67 of 108) meeting STEMI criteria. Median peak troponin T for the STEMI(+) OMI, STEMI(-) OMI, and no occlusion groups were 3.78 (interquartile range [IQR] 2.18-7.63), 1.87 (IQR 1.12-5.48), and 0.00 (IQR 0.00-0.08). Median time from arrival to catheterization was 41 min (IQR 23-86 min) for STEMI(+) OMI compared with 437 min (IQR 85-1590 min) for STEMI(-) OMI (p < 0.001). STEMI(+) OMI was more likely than STEMI(-) OMI to undergo catheterization within 90 min (76% vs. 28%; p < 0.001). CONCLUSIONS: STEMI(-) OMI patients had significant delays to catheterization but adverse outcomes more similar to STEMI(+) OMI than those with no occlusion. These data support the OMI/NOMI paradigm and the importance of further research into emergent reperfusion for STEMI(-) OMI.

Dynamic T-wave inversions in the setting of left bundle branch block.

We illustrate the case a patient with left bundle branch block (LBBB) and electrocardiogram (ECG) changes consistent with those described in Wellens' syndrome. The characteristic ECG findings of Wellens' syndrome identify patients who have a particularly high rate of important coronary events in the near future, however these findings have previously been described only in the setting of normal conduction. A review of Wellens' syndrome, its criteria and pathophysiology, and its proposed appearance in the setting of LBBB is presented.

Evaluation of T-Wave Morphology in Patients With Left Bundle Branch Block and Suspected Acute Coronary Syndrome.

BACKGROUND: T-wave morphology in the setting of left bundle branch block (LBBB) has been proposed as an indicator of myocardial ischemia. OBJECTIVES: We sought to identify T-wave morphology findings in patients with LBBB that predict non-ST-segment elevation myocardial infarction (NSTEMI). We hypothesized that two or more contiguous leads with concordant T waves would be predictive of NSTEMI. METHODS: This was a retrospective cohort study performed by chart review in a tertiary care center emergency department. We identified a consecutive cohort who presented with LBBB and symptoms consistent with acute coronary syndrome. Exclusion criteria were diastolic blood pressure > 120 mm Hg, heart rate > 130 beats/min, positive pressure ventilation, potassium > 5.5 mEq/L, and cardiac arrest without prearrest electrocardiogram (ECG) available. We collected ECGs and classified T waves into five categories based on morphology, blinded to clinical outcome. Clinical outcome data were collected blinded to ECG findings. Those with ECG diagnostic of STEMI by modified Sgarbossa criteria were excluded from the primary analysis, which was sensitivity and specificity of two or more contiguous leads with concordant T waves for NSTEMI. RESULTS: There were 246 patients included. Mean age was 73 years; 160 (65%) were female, and 32 had myocardial infarction. Thirty percent had two or more contiguous precordial leads with partially or completely concordant T waves. For NSTEMI, the sensitivity and specificity of this finding were 19% (95% confidence interval [CI] 8-37) and 68% (95% CI 61-74). CONCLUSIONS: We found no clinically useful relationship between T-wave concordance and myocardial infarction in our patient population. Future investigation of LBBB T-wave morphology should focus on alternative populations and findings.

Validation of the modified Sgarbossa criteria for acute coronary occlusion in the setting of left bundle branch block: A retrospective case-control study.

BACKGROUND: The modified Sgarbossa criteria were proposed in a derivation study to be superior to the original criteria for diagnosing acute coronary occlusion (ACO) in left bundle branch block (LBBB). The new rule replaces the third criterion (5 mm of excessively discordant ST elevation [STE]) with a proportion (at least 1 mm STE and STE/S wave ≤-0.25). We sought to validate the modified criteria. METHODS: This retrospective case-control study was performed by chart review in 2 tertiary care center emergency departments (EDs) and 1 regional referral center. A billing database was used at 1 site to identify all ED patients with LBBB and ischemic symptoms between May 2009 and June 2012. In addition, all 3 sites identified LBBB ACO patients who underwent emergent catheterization. We measured QRS amplitude and J-point deviation in all leads, blinded to outcomes. Acute coronary occlusion was determined by angiographic findings and cardiac biomarker levels, which were collected blinded to electrocardiograms. Diagnostic statistics of each rule were calculated and compared using McNemar's test. RESULTS: Our consecutive cohort search identified 258 patients: 9 had ACO, and 249 were controls. Among the 3 sites, an additional 36 cases of ACO were identified, for a total of 45 ACO cases and 249 controls. The modified criteria were significantly more sensitive than the original weighted criteria (80% vs 49%, P < .001) and unweighted criteria (80% vs 56%, P < .001). Specificity of the modified criteria was not statistically different from the original weighted criteria (99% vs 100%, P = .5) but was significantly greater than the original unweighted criteria (99% vs 94%, P = .004). CONCLUSIONS: The modified Sgarbossa criteria were superior to the original criteria for identifying ACO in LBBB.

Quantifying Patient-Physician Communication and Perceptions of Risk During Admissions for Possible Acute Coronary Syndromes.

STUDY OBJECTIVE: Disposition decision for patients with possible acute coronary syndrome in the emergency department (ED) is driven primarily by perception of short-term risks. We sought to evaluate communication between patient and physician about these risks by ascertaining the content of discussions surrounding disposition decision. METHODS: We conducted matched-pair surveys of patients admitted for possible acute coronary syndrome and their physicians in 2 academic, inner-city EDs. After disposition conversation, trained research assistants administered surveys querying perceived and communicated risk estimates and purpose of admission. Primary exclusion criteria were ECG or troponin value diagnostic of acute coronary syndrome. The primary outcome measure was agreement in assessment of the risk of myocardial infarction, defined as the proportion of patient-physician pairs whose risk estimates were within 10% of each other. RESULTS: A total of 425 patient-physician survey pairs were collected. Fifty-three percent of patients were men. Patients reported discussing the likelihood of their symptoms' being due to myocardial infarction in 65% of cases, whereas physicians reported this in 46%. After their discussion, physicians' (n=415) median estimate of short-term risk was 5% (95% confidence interval [CI] 3% to 7%), whereas patients' (n=401) was 8% (95% CI 5% to 11%). Most patients (63%; 95% CI 57% to 67%) reported that this estimate remained the same or increased after their conversation. Risk agreement within 10% occurred in 36% of cases (n=404; 95% CI 32% to 41%). Patients' median estimates of the mortality of myocardial infarction at home versus in the hospital were 80% (n=398; 95% CI 76% to 84%) and 10% (n=390; 95% CI 7% to 13%), respectively, whereas physician estimates were 15% (n=403; 95% CI 12% to 18%) and 10% (n=398; 95% CI 7% to 13%). CONCLUSION: Our survey demonstrates poor communication, with overestimation of both the risks of myocardial infarction and potential benefit of hospital admission. These findings suggest that communication surrounding disposition decisions in chest pain patients may at times be ineffective or misleading.

Bizarre T Waves: What Do They Mean?

Electrocardiographic artifacts are common and may often interfere with interpretation. We describe a case of bizarre appearing T waves. The left arm electrode was placed near a pulsatile fistula, which created an artery pulse tapping artifact. When encountering unexpected electrocardiographic findings, inspection of the electrocardiogram and lead placement may identify the cause. (Level of Difficulty: Intermediate.).

Time for a new paradigm shift in myocardial infarction.

The ST-elevation myocardial infarction (STEMI)/non-STEMI paradigm per the current guidelines has important limitations. It misses a substantial proportion of acute coronary occlusions (ACO) and results in a significant amount of unnecessary catheterization laboratory activations. It is not widely appreciated how poor is the evidence base for the STEMI criteria; the recommended STEMI cutoffs were not derived by comparing those with ACO with those without and not specifically designed for distinguishing patients who would benefit from emergency reperfusion. This review aimed to discuss the origins, evidence base, and limitations of STEMI/non-STEMI paradigm and to call for a new paradigm shift to the occlusion MI (OMI)/non-OMI.

Recognizing electrocardiographically subtle occlusion myocardial infarction and differentiating it from mimics: Ten steps to or away from cath lab.

It is increasingly evident that the ST-segment elevation (STE) myocardial infarction (MI)/non-STEMI paradigm that equates STEMI with acute coronary occlusion (ACO) is deceptive. This unfortunate paradigm, adhered to by the current guidelines, misses at least one-fourth of the ACOs, and unnecessarily over-triages a similar fraction of the patients to the catheterization laboratory. Accordingly, we have been calling for a new paradigm, the occlusion/nonocclusion MI (OMI/NOMI). Although this new OMI/NOMI paradigm is not limited to an electrocardiogram (ECG), the ECG will remain the cornerstone of this new paradigm because of its speed, repeatability, noninvasive nature, wide availability, and high diagnostic power for OMI. This review provides a step-by-step approach to ECG for the diagnosis of OMI.

Ischemic ST-Segment Depression Maximal in V1-V4 (Versus V5-V6) of Any Amplitude Is Specific for Occlusion Myocardial Infarction (Versus Nonocclusive Ischemia).

Background Occlusion myocardial infarctions (OMIs) of the posterolateral walls are commonly missed by ST-segment-elevation myocardial infarction (STEMI) criteria, with >50% of patients with circumflex occlusion not receiving emergent reperfusion and experiencing increased mortality. ST-segment depression maximal in leads V1-V4 (STDmaxV1-4) has been suggested as an indicator of posterior OMI. Methods and Results We retrospectively reviewed a high-risk population with acute coronary syndrome. OMI was defined from prior studies as a culprit lesion with TIMI (Thrombolysis in Myocardial Infarction) 0 to 2 flow or TIMI 3 flow plus peak troponin T >1.0 ng/mL or troponin I >10 ng/mL. STEMI was defined by the Fourth Universal Definition of Myocardial Infarction. ECGs were interpreted blinded to outcomes. Among 808 patients, there were 265 OMIs, 108 (41%) meeting STEMI criteria. A total of 118 (15%) patients had "suspected ischemic" STDmaxV1-4, of whom 106 (90%) had an acute culprit lesion, 99 (84%) had OMI, and 95 (81%) underwent percutaneous coronary intervention. Suspected ischemic STDmaxV1-4 had 97% specificity and 37% sensitivity for OMI. Of the 99 OMIs detected by STDmaxV1-4, 34% had <1 mm ST-segment depression, and only 47 (47%) had accompanying STEMI criteria, of which 17 (36%) were identified a median 1.00 hour earlier by STDmaxV1-4 than STEMI criteria. Despite similar infarct size, TIMI flow, and coronary interventions, patients with STEMI(-) OMI and STDmaxV1-4 were less likely than STEMI(+) patients to undergo catheterization within 90 minutes (46% versus 68%; P=0.028). Conclusions Among patients with high-risk acute coronary syndrome, the specificity of ischemic STDmaxV1-4 was 97% for OMI and 96% for OMI requiring emergent percutaneous coronary intervention. STEMI criteria missed half of OMIs detected by STDmaxV1-4. Ischemic STDmaxV1-V4 in acute coronary syndrome should be considered OMI until proven otherwise.