The utility of the triage electrocardiogram for the detection of ST-segment elevation myocardial infarction

Factors for delays in door-to-balloon time ≤ 90 min in an electrocardiogram triage system among patients with ST-segment elevation myocardial infarction: a retrospective study

BACKGROUND

Door to balloon time is a crucial factor of mortality in patients with ST-segment elevation myocardial infarction. However, the factors that contribute to failure of achieving door to balloon time ≤ 90 min in an electrocardiogram triage system remain unknown.

METHODS

This single-center retrospective observational study collected data from consecutive patients with ST-segment elevation myocardial infarction from April 2016 to March 2021. The primary outcome was the failure to achieve door to balloon time ≤ 90 min. A multivariate logistic regression model was performed to predict factors associated with failure to achieve door to balloon time ≤ 90 min.

RESULTS

In total, 190 eligible patients were included. Of these, the 139 (73.2%) patients with door to balloon time ≤ 90 min were significantly younger compared to those with door to balloon time > 90 min (p = 0.02). However, there was no significant difference in sex and timing of hospital arrival between the door to balloon time ≤ 90 and > 90 min groups. Presence of chest pain and ambulance usage were significantly more frequent in patients with door to balloon time ≤ 90 min (p ≤ 0.01, p = 0.02, respectively). Multivariate analysis showed that absence of chest pain (adjusted odds ratio 4.76; 95% confidence interval, 2.04-11.1; p < 0.01) and non-ambulance usage (adjusted odds ratio 3.53; 95% confidence interval, 1.57-7.94; p < 0.01) are predictive factors of failure to achieve door to balloon time ≤ 90 min.

CONCLUSION

Patients without chest pain as the chief complaint or non-ambulance usage were significantly associated with the failure to achieve door to balloon time ≤ 90 min.

Compared with physician overread, computer is less accurate but helpful in interpretation of electrocardiography for ST-segment elevation myocardial infarction

INTRODUCTION

Previous studies have demonstrated varying sensitivity and specificity of computer-interpreted electrocardiography (CIE) in identifying ST-segment elevation myocardial infarction (STEMI). This study aims to evaluate the accuracy of contemporary computer software in recognizing electrocardiography (ECG) signs characteristic of STEMI compared to emergency physician overread in clinical practice.

MATERIAL AND METHODS

In this retrospective observational single-center study, we reviewed the records of patients in the emergency department (ED) who underwent ECGs and troponin tests. Both the Philips DXL 16-Lead ECG. Algorithm and on-duty emergency physicians interpreted each standard 12‑lead ECG. The sensitivity and specificity of computer interpretation and physician overread ECGs for the definite diagnosis of STEMI were calculated and compared.

RESULTS

Among the 9340 patients included in the final analysis, 133 were definitively diagnosed with STEMI. When "computer-reported infarct or injury" was used as the indicator, the sensitivity was 87.2% (95% CI 80.3% to 92.4%) and the specificity was 86.2% (95% CI 85.5% to 86.9%). When "physician-overread STEMI" was used as the indicator, the sensitivity was 88.0% (95% CI 81.2% to 93.0%) and the specificity was 99.9% (95% CI 99.8% to 99.9%). The area under the receiver operating characteristic curve for physician-overread STEMI and computer-reported infarct or injury were 0.939 (95% CI 0.907 to 0.972) and 0.867 (95% CI 0.834 to 0.900), respectively.

CONCLUSIONS

This study reveals that while the sensitivity of the computer in recognizing ECG signs of STEMI is similar to that of physicians, physician overread of ECGs is more specific and, therefore, more accurate than CIE.

Emergent cardiac outcomes in patients with normal electrocardiograms in the emergency department

BACKGROUND

Emergency physicians (EP) are frequently interrupted to screen electrocardiograms (ECG) from Emergency Department (ED) patients undergoing triage. Our objective was to identify discrepancies between the computer ECG interpretation and the cardiologist ECG interpretation and if any patients with normal ECGs underwent emergent cardiac intervention. We hypothesized that computer-interpreted normal ECGs do not require immediate review by an EP.

METHODS

This was a retrospective study of adult (≥ 18 years old) ED patients with computer-interpreted normal ECGs. Laboratory, diagnostic testing and clinical outcomes were abstracted following accepted methodologic guidelines. The primary outcome was emergent cardiac catheterization (within four hours of ED arrival). All ECGs underwent final cardiologist interpretation. When cardiology interpretation differed from the computer (discrepant ECG interpretation), the difference was classified as potentially clinically significant or not clinically significant. Data was described with simple descriptive statistics.

MAIN FINDINGS

989 ECGs interpreted as normal by the computer were analyzed with a mean age of 50.4 ± 16.8 years (range 18-96 years) and 527 (53%) female. Discrepant ECG interpretations were identified in 184 cases including 124 (12.5%, 95% CI 10.4, 14.7%) not clinically significant and 60 (6.1%, 95% CI 4.6, 7.7%) potentially clinically significant. The 60 potentially clinically significant changes included: ST/T wave changes 45 (75%), T wave inversions 6 (10%), prolonged QT 3 (5%), and possible ischemia 10 (17%). Of these 60, 21 (35%) patients were admitted. Six patients had potassium levels >6.0 mEq/L, with one having a potentially clinically significant ECG change. No patient (0%, 95% CI 0, 0.3%) underwent immediate (within four hours) cardiac catherization whereas two underwent delayed cardiac interventions.

CONCLUSIONS

Cardiologists frequently disagree with a computer-interpreted normal ECG. Patients with computer-interpreted normal ECGs, however, rarely had significant ischemic events. A rare number of patients will have important cardiac outcomes regardless of the computer-generated normal ECG interpretation. Immediate EP review of the ECG, however, would not have changed these patients' ED courses.

A modified cardiac triage strategy reduces door to ECG time in patients with ST elevation myocardial infarction

Timely performing electrocardiography (ECG) is crucial for early detection of ST-elevation myocardial infarction (STEMI). For shortening door-to-ECG time, a chief complaint-based “cardiac triage” protocol comprising (1) raising alert among medical staff with bedside triage tags, and (2) immediate bedside ECG after focused history-taking was implemented at the emergency department (ED) in a single tertiary referral center. All patients diagnosed with STEMI visiting the ED between November 2017 and January 2020 were retrospectively reviewed to investigate the effectiveness of strategy before and after implantation. Analysis of a total of 117 ED patients with STEMI (pre-intervention group, n = 57; post-intervention group, n = 60) showed significant overall improvements in median door-to-ECG time from 5 to 4 min (p = 0.02), achievement rate of door-to-ECG time < 10 min from 45 to 57% (p = 0.01), median door-to-balloon time from 81 to 70 min (p < 0.01). Significant trends of increase in achievement rates for door-to-ECG and door-to-balloon times (p = 0.032 and p = 0.002, respectively) was noted after strategy implementation. The incidences of door-to-ECG time > 10 min for those with initially underestimated disease severity (from 90 to 10%, p < 0.01) and walk-in (from 29.2 to 8.8%, p = 0.04) were both reduced. In conclusion, a chief complaint-based “cardiac triage” strategy successfully improved the quality of emergency care for STEMI patients through reducing delays in diagnosis and treatment.

A prospective analysis of time to screen protocol ECGs in adult Emergency Department triage patients

BACKGROUND

Early identification of ST elevation MI (STEMI) in emergency departments (ED) via electrocardiogram (ECG) expedites intervention. While screening of all ED chest pain ECGs should be obtained within 10 minutes per the American Heart Association, 40% of all ECGs are software-analyzed as "Normal" or "Otherwise Normal." However, the reliability of this analysis and the time for confirmation read are uncertain. This study investigates the time necessary for Patient Care Technicians (PCTs) to deliver ECGs to ED attendings to confirm automated interpretation.

METHODS

A prospective cohort study was conducted at a single academic ED. All patients ≥18 years who had a triage ECG were included. ECGs were obtained within 10 min of arrival, time-stamped, delivered for ED attending review and time-stamped upon PCT return to triage. Data were entered into REDCap and analyzed using StatPlus.

RESULTS

During the 4-month study, 1768 ECGs were collected. Distribution of automated readings was: "Normal ECG" 33.7%; "Otherwise Normal ECG" 11.2%; and "borderline/abnormal" 55.1%. The median time necessary for PCTs to confirm a screening ECG was 2.8 min (IQR 2,4) with attending physicians interrupted an average of 14.6 times per day.

CONCLUSION

Screening of triage ECGs is time-intensive and compounds the frequency of physician interruptions. Although findings are not generalizable, the impact of these interruptions on patient care and safety is paramount and universal. Future directions include validating the reliability of "Normal" and "Otherwise Normal" ECG automated readings to obviate the need to interrupt ED physician for expedited screening confirmation.