Comparison between human and automated electrocardiographic waveform measurements for calculating the Anderson-Wilkins acuteness score in patients with acute myocardial infarction

The high-risk ECG pattern of ST-elevation myocardial infarction: A substudy of the randomized trial of primary PCI with or without routine manual thrombectomy (TOTAL trial)

BACKGROUND

Useful tools for risk assessment in patients with STEMI are needed. We evaluated the prognostic impact of the evolving myocardial infarction (EMI) and the preinfarction syndrome (PIS) ECG patterns and determined their correlation with angiographic findings and treatment strategy.

METHODS

This substudy of the randomized Trial of Routine Aspiration Thrombectomy with PCI versus PCI Alone in Patients with STEMI (TOTAL) included 7860 patients with STEMI and either the EMI or the PIS ECG pattern. The primary outcome was a composite of death from cardiovascular causes, recurrent MI, cardiogenic shock, or New York Heart Association (NYHA) class IV heart failure within one year.

RESULTS

The primary outcome occurred in 271 of 2618 patients (10.4%) in the EMI group vs. 322 of 5242 patients (6.1%) in the PIS group [AdjustedHR, 1.54; 95% CI, 1.30 to 1.82; p < .001]. The primary outcome occurred in the thrombectomy and PCI alone groups in 131 of 1306 (10.0%) and 140 of 1312 (10.7%) patients with EMI [HR 0.94; 95% CI, 0.74-1.19] and 162 of 2633 (6.2%) and 160 of 2609 (6.1%) patients with PIS [HR 1.00; 95% CI, 0.81-1.25], respectively (p_interaction = 0.679).

CONCLUSIONS

Patients with the EMI ECG pattern proved to have an increased rate of the primary outcome within one year compared to the PIS pattern. Routine manual thrombectomy did not reduce the risk of primary outcome within the different dynamic ECG patterns. The PIS/EMI dynamic ECG classification could help to triage patients in case of simultaneous STEMI patients with immediate need for pPCI.

Agreement between cardiologists and fellows in interpretation of ischemic electrocardiographic changes in acute myocardial infarction

BACKGROUND

Time from symptom onset may not be the best indicator for choosing reperfusion therapy for patients presenting with acute ST-elevation myocardial infarction (STEMI); consequently ECG-based methods have been developed.

METHODS

This study evaluated the inter-observer agreement between experienced cardiologists and junior doctors in identifying the ECG findings of the pre-infarction syndrome (PIS) and evolving myocardial infarction (EMI). The ECGs of 353 STEMI patients were independently analyzed by two cardiologists, one fellow in cardiology, one fellow in internal medicine and a medical student. The last two were given a half-hour introduction of the PIS/EMI-algorithm.

RESULTS

The inter-observer reliability between all the investigators was found to be good according to kappa statistics (κ 0.632-0.790) for the whole study population. When divided into different subgroups, the inter-observer agreements were from good to very good between the cardiologists and the fellow in cardiology (κ 0.652 -0.813) and from moderate to good (κ 0.464-0.784) between the fellow in internal medicine, medical student and the others.

CONCLUSIONS

The PIS and EMI ECG patterns are reliably identified by experienced cardiologists and can be easily adopted by junior doctors.

Comparison of an automated algorithm to expert physician interpretation of 80-lead body surface mapping in the evaluation of acute myocardial ischemia and infarction in patients presenting to the emergency department with chest pain: results from the Optimal Cardiovascular Diagnostic Evaluation Enabling Faster Treatment of Myocardial Infarction trial

INTRODUCTION/BACKGROUND

Eighty-lead (80 L) body surface map (BSM) technology provides electrocardiogram data for the clinician to interpret. A BSM device also offers an automated interpretation. Little information is available about the performance of automated algorithm interpretation in comparison to human interpretation of the 80 L BSM.

METHODS

Interpretations of BSMs by automated algorithm and a core laboratory of physician readers from The Optimal Cardiovascular Diagnostic Evaluation Enabling Faster Treatment of Myocardial Infarction trial were compared. The κ statistic and its 95% confidence interval for concordance were calculated. The effect of BSM quality on concordance was also analyzed.

RESULTS

3405 maps for 1601 subjects were reviewed by the core laboratory and automated algorithm. There was a combined concordance rate of 87.3% (κ = 0.46; 95% confidence interval, 0.40-0.52). A decrease in signal quality was associated with a decrease in concordance between human and automated algorithm interpretation (κ = 0.52 for good quality vs κ = 0.30 for poor quality).

CONCLUSION

A moderate degree of concordance was noted between physician and automated algorithm interpretation of 80 L BSMs. Signal quality of 80 L electrocardiographic BSM directly affected concordance.

Timing of ischemic onset estimated from the electrocardiogram is better than historical timing for predicting outcome after reperfusion therapy for acute anterior myocardial infarction: a DANish trial in Acute Myocardial Infarction 2 (DANAMI-2) substudy

BACKGROUND

Acute treatment strategy and subsequently prognosis are influenced by the duration of ischemia in patients with ST-elevation acute myocardial infarction (AMI). However, timing of ischemia may be difficult to access by patient history (historical timing) alone. We hypothesized that an electrocardiographic acuteness score is better than historical timing for predicting myocardial salvage and prognosis in patients with anterior AMI treated with fibrinolysis or primary percutaneous coronary intervention.

METHODS

One hundred seventy-five patients with anterior infarct without electrocardiogram (ECG) confounding factors were included. The ECG method for estimating timing of AMI was calculated using core laboratory measurements from the initial 12-lead ECG. Historical timing was recorded as time from symptom onset to initiation of reperfusion therapy. Myocardial salvage was determined by ECG, using the Aldrich score to determine the initially predicted myocardial infarct size and the Selvester score to determine the final QRS-estimated myocardial infarct size.

RESULTS

The mean amount of myocardium salvage depended on ECG timing (43% [+/-38%] for "early" vs 1% [+/-56%] for "late"; P < .001), whereas myocardial salvage was independent of historical timing (P = .9). One-year mortality was predicted from ECG timing (P = .04).

CONCLUSIONS

The ECG method of timing was superior to historical timing in predicting myocardial salvage and prognosis after reperfusion therapy. This study suggests that ECG estimated duration of ischemia might provide a better and objective means to select acute reperfusion therapy rather than the subjective patient history, which could preclude proper reperfusion in some patients with salvageable myocardium.

Electrocardiogram dynamics for risk stratification in ST-segment elevation myocardial infarction—immediate and serially updated information on outcome

Early and serially updated predictions of final infarct-size and clinical outcome--before, during and after reperfusion treatment of ST-elevation myocardial infarction might allow a more individualized treatment: High-risk patients with a predicted major loss of viable myocardium can be identified immediately or during therapy, at a stage when treatment may still be modified; and low-risk patients with predictions of small infarcts and good outcome already after standard primary reperfusion therapy can be identified and thereby avoid a possibly harmful intensified treatment. The necessary information for such predictions seem to be available from the standard 12-lead ECG and from ST-segment monitoring. Today this information, however, is not readily available in clinical practice. Automated algorithms need to be engineered for a broader use and for possibilities of a refined triage and thus for a more individualized strategy of reperfusion therapy.

Electrocardiogram of acute ST-elevation myocardial infarction: the significance of the various "scores"

The Electrocardiogram has extensively been used for evaluation and triage of patients with acute chest pain. The clinician admitting a patient with ST elevation acute myocardial infarction should be able to estimate the size and location of the ischemic area at risk, how much of the ischemic myocardium has already undergone irreversible necrosis by the time of presentation, and the "severity of ischemia" (or what is the rate of progression of necrosis as long as ischemia continues). The electrocardiographic variables that are used to make these estimates are the initial portion of the QRS (Q and R waves), the terminal portion of the QRS (the S waves and the J-point), the ST segment, and the configuration of the T waves. This editorial discuss the ability to predict each of the "physiological" parameters using the above mentioned electrocardiographic variables.