Electrocardiographic measurement of infarct size compared to cardiac MRI in reperfused first time ST-segment elevation myocardial infarction

Predictive role of Frontal QRS-T angle and Selvester QRS Score in determining angiographic slow flow phenomenon following percutaneous coronary intervention in patients with Non-ST elevation myocardial infarction

AIM

Slow flow (SF) that develops after percutaneous coronary intervention (PCI) is significantly associated with poor prognosis in Non-ST elevation myocardial infarction (Non-STEMI) patients. Increased Selvester QRS score and Frontal QRS-T angle [f(QRS-T)] are related to adverse cardiovascular outcomes. We aimed to investigate the predictive role of the Selvester QRS score and f(QRS-T) for the development of post-PCI SF in patients with Non-STEMI.

METHOD AND RESULTS

In a retrospective study, 210 patients with Non-STEMI were divided into two groups as SF (29) and Non-SF (181) according to their TIMI coronary flow grade. For all patients the Selvester QRS score and f(QRS-T) were calculated from automatic electrocardiography (ECG) reports. The mean age of the study population was 63 (55-75) years and 102 (68.6%) of patients were male. The Selvester QRS score and f(QRS-T) were higher in the SF group than in the Non-SF group [(5[3-8], 3[2-5]); (67° [42°-88°], 39° [24°-59°]), respectively, all p <0.01]. In a logistic regression analysis, the Selvester QRS score (OR = 4,862; 95% (CI) = 1,131-20,904, p =0.03) and f(QRS-T) (OR = 5,489; 95% (CI)= 11,433-21,034, p =0.01) were found independent predictors of post-PCI SF in Non-STEMI patients. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic values of the Selvester QRS score [86% sensitivity; 44% specificity; cut off 2; (AUC, 0.693)] and f(QRS-T) [62% sensitivity; 73% specificity; cut off 58°; (AUC, 0.778)].

CONCLUSION

The Selvester QRS score and f(QRS-T), both easy-to-calculate ECG parameters, are predictors of post-PCI SF in Non-STEMI patients.

Electrocardiographic criteria for anterior STEMI - Does the cut-off point affect treatment delay?

BACKGROUND

Diagnostic criteria for anterior STEMI differ between the European Society of Cardiology (ESC) and the European Resuscitation Council (ERC). A greater degree of ST-segment elevation is required to meet ERC criteria compared to ESC criteria. This may potentially lead to discrepancies in management between emergency teams and cardiologists, subsequent delay in reperfusion therapy and worse prognosis.

METHODS

We performed an observational study in patients with anterior STEMI routinely treated with primary PCI and assessed whether differing electrocardiographic diagnostic criteria could impact treatment and short-term prognosis. All patients in the study had anterior STEMI confirmed by electrocardiographic ESC criteria and subsequent coronary angiography. Patients were divided into two groups. Those who did not meet ERC criteria in the index ECG were assigned to the "non-ERC" group and were compared with those who met them - the "ERC" group.

RESULTS

Out of 60 patients with anterior STEMI based on ESC criteria (mean age 66.9 ± 13.6 years, 70% males), 26 patients (44%) did not meet ERC criteria ("non-ERC" group) for STEMI. There were no significant differences in age, gender distribution or clinical characteristics between "ERC" and "non-ERC" patients. Total-Ischemic-Time, Patient-Delay, and System-Delay times were significantly longer in "non-ERC" group (433.1 ± 389.9 min vs. 264.2 ± 229.6 min, p = 0.03; 290.8 ± 337.6 min vs. 129.5 ± 144.9 min; p < 0.05 and 158.8 ± 158 vs 134.6 ± 191 min, p < 0.02 respectively). There were no differences in In-Hospital-Delay, procedure duration, and success rate of PCI. Proximal LAD occlusion (64.7%) and TIMI = 0 flow (73.5%) tended to be more frequently observed in "ERC" than in the "non-ERC" group (53.8% and 65.4%, respectively). Hospitalization time and LVEF (44.4 ± 8.7 vs 42.8 ± 9.5%, p = 0.53) were similar between groups.

CONCLUSIONS

Differences in electrocardiographic criteria for anterior STEMI leave a significant proportion of patients undiagnosed. Patients with STEMI who failed to meet less strict ERC criteria had more distal LAD disease with better TIMI flow but received reperfusion therapy later. Thus, character of the disease may compensate for treatment delay but this needs to be further evaluated. Finally, lowering the cut-off point with stricter criteria compromises specificity and is expected to increase the false positive rate, however there were no false positives in this study as all patients were angiographically confirmed to have acute coronary obstruction.

Complete versus simplified Selvester QRS score for infarct severity assessment in ST-elevation myocardial infarction

Background

Complete and simplified Selvester QRS score have been proposed as valuable clinical tool for estimating myocardial damage in patients with ST-elevation myocardial infarction (STEMI). We sought to comprehensively compare both scoring systems for the prediction of myocardial and microvascular injury assessed by cardiac magnetic resonance (CMR) imaging in patients with acute STEMI.

Methods

In this prospective observational study, 201 revascularized STEMI patients were included. Electrocardiography was conducted at a median of 2 (interquartile range 1–4) days after the index event to evaluate the complete and simplified QRS scores. CMR was performed within 1 week and 4 months thereafter to determine acute and chronic infarct size (IS) as well as microvascular obstruction (MVO).

Results

Complete and simplified QRS score showed comparable predictive value for acute (area under the curve (AUC) = 0.64 vs. 0.67) and chronic IS (AUC = 0.63 vs. 0.68) as well as for MVO (AUC = 0.64 vs. 0.66). Peak high sensitivity cardiac troponin T (hs-cTnT) showed an AUC of 0.88 for acute IS and 0.91 for chronic IS, respectively. For the prediction of MVO, peak hs-cTnT represented an AUC of 0.81.

Conclusions

In reperfused STEMI, complete and simplified QRS score displayed comparable value for the prediction of acute and chronic myocardial as well as microvascular damage. However, both QRS scoring systems provided inferior predictive validity, compared to peak hs-cTnT, the clinical reference method for IS estimation.

Differences in the Selvester QRS score after primary PCI strategy and conservative treatment for STEMI patients with negative T waves

BACKGROUND

According to current guidelines, the main indications for PCI in patients with STEMI are ST-segment deviations and defined time from the onset of symptoms. Negative T wave at admission can be a sign of prolonged ischemia or spontaneous reperfusion. In both situations, the urgent intervention is questionable. We evaluated the infarct size and in-hospital mortality in STEMI patients with negative T wave in cases of primary PCI strategy compared with conservative treatment.

METHODS

A retrospective analysis of 116 STEMI patients with negative T wave at the presenting ECG was performed. Sixty-eight patients (59%) underwent primary PCI strategy (PCI group), and 48 (41%) were treated conservatively (non-PCI group). The infarct size estimated by using the Selvester score, and in-hospital mortality were evaluated.

RESULTS

The difference between Selvester score values at admission and at discharge in the non-PCI group was statistically significant (1.48; 95% CI 0.694-2.27), while no significant difference was observed in the PCI group (-0.07; 95% CI -0.546-0.686). The in-hospital mortality was higher in the non-PCI group; however, the numbers were relatively small: PCI 2 (2.9%) and non-PCI 5 (10.4%).

CONCLUSION

In this study, we showed a reduction in the infarct size estimated by Selvester score in STEMI patients with negative T wave who were treated conservatively, while there was no significant change in the infarct size after primary PCI strategy. The higher mortality in patients treated conservatively could be attributed to higher age and comorbidities in the non-PCI group. It seems that conservative treatment strategy might be an option in STEMI patients with negative T wave.

Persistent T-wave inversion predicts myocardial damage after ST-elevation myocardial infarction

BACKGROUND

Persistent T-wave inversion (PTI) after ST-elevation myocardial infarction (STEMI) is associated with worse clinical outcome; however, the underlying mechanism between PTI and poor prognosis is incompletely understood. We sought to investigate the relationship between PTI and myocardial damage assessed by cardiac magnetic resonance (CMR) following STEMI.

METHODS

In this prospective observational study, we included 142 consecutive revascularized STEMI patients. Electrocardiography to determine the presence and amplitude of PTI and pathological Q-waves was conducted 4months after infarction. CMR was performed within 1week after infarction and at 4months follow-up to evaluate infarct characteristics and myocardial function.

RESULTS

Patients with PTI (n=103, 73%) showed a larger acute (21[11-29] vs. 6[1-13]%; p<0.001) and chronic infarct size (IS) (14[8-19] vs. 3[1-8]%; p<0.001) and more frequently microvascular obstruction (59 vs. 33%; p=0.02). The association between PTI and chronic IS remained significant (odds ratio: 9.02, 95%CI 3.49-23.35; p<0.001) after adjustment for pathological Q-wave and other IS estimators (high-sensitivity cardiac troponin T and C-reactive protein, N-terminal pro B-type natriuretic peptide, culprit vessel, pre-interventional TIMI flow). The value of PTI amplitude for the prediction of large chronic IS>11% (AUC: 0.84, 95%CI 0.77-0.90) was significantly higher compared to Q-wave amplitude (AUC: 0.72, 95%CI 0.63-0.80; p=0.009); the combination of PTI with pathological Q-wave (Q-wave/T-wave score) led to a net reclassification improvement of 0.43 (95% CI 0.29-0.57; p<0.001) as compared to PTI alone.

CONCLUSIONS

PTI following STEMI is independently and incrementally associated with more extensive myocardial damage as visualized by CMR. An electrocardiographic score combining PTI with pathological Q-wave allows for a highly accurate IS estimation post-STEMI.