Quantitative T-wave analysis predicts 1 year prognosis and benefit from early invasive treatment in the FRISC II study population

Risikostratifizierung des NSTE-ACS

Mit zunehmender Verbesserung der Prognose der NSTE-ACS-Patientenkollektive in den letzten Jahren spielt eine standardisierte, schnelle und gute diskriminierende Risikostratifizierung eine erhebliche Rolle. Verschiedene Merkmale des langfristig erwartbaren ischämischen Risikos, wie z.B. klinische Parameter, EKG-Indikatoren, Biomarker und klinische Scores, werden zusammen mit dem individuellen Blutungsrisiko erfasst und integriert. So ist z.B. die absolute Höhe der Troponin-Konzentration prädiktiv für die Gesamtletalität. Der GRACE-Risk-Score wird nicht nur zusätzlich zur objektiven Risikostratifizierung empfohlen, sondern ein Punktwert >140 ist eines der Kriterien für eine frühe Koronarangiografie innerhalb von 24 Stunden. Die Abschätzung des Blutungsrisikos entsprechend der ARC-HBR-Kriterien hat einen Einfluss auf das antithrombotische Therapieregime.

Prognostic value of admission electrocardiographic findings in non-ST-segment elevation myocardial infarction

BACKGROUND

Admission electrocardiographic (ECG) findings of non-ST-segment elevation myocardial infarction (NSTEMI) include transient ST-segment elevation (TSTE), ST-segment depression (STD), T-wave inversion (TWI), and no ischemic changes (NIC).

HYPOTHESIS

This study aimed to assess the prognostic value of qualitative ECG findings at presentation and to clarify the influence of invasive treatment on the prognostic value of admission ECG findings.

METHODS

We analyzed the Acute Coronary Syndrome Quality Improvement in Kerala (ACS QUIK) study post hoc. NSTEMI patients were included and classified into four groups per ECG findings. Study endpoints were in-hospital and 30-day mortality rates and major adverse events (MAE). We performed multivariate logistic regression, adjusting for covariates in the Global Registry of Acute Coronary Events risk model, with subset analyses of patients treated with or without invasive management.

RESULTS

STD patients had significantly higher in-hospital and 30-day mortality rates/MAE than TWI patients, which had lower in-hospital mortality rate/MAE than the NIC group. TSTE patients had intermediate outcomes. In multivariate logistic regression using the TWI group as the reference, STD and NIC remained independently associated with worse outcomes. Subset analysis showed prognostic value of admission ECG in non-invasively managed but not in invasively managed patients.

CONCLUSIONS

STD was associated with adverse outcomes, TWI with benign prognoses. NIC should not be taken to indicate low risk. Qualitative analysis of admission ECG is suitable for rapid risk stratification of NSTMI patients at presentation. However, it may not be predictive of short-term outcomes of NSTEMI patients after invasive management.

ECG analysis in patients with acute coronary syndrome undergoing invasive management: rationale and design of the electrocardiography sub-study of the MATRIX trial

BACKGROUND

The twelve‑lead electrocardiogram (ECG) has become an essential tool for the diagnosis, risk stratification, and management of patients with acute coronary syndromes (ACS). However, several areas of residual controversies or gaps in evidence exist. Among them, P-wave abnormalities identifying atrial ischemia/infarction are largely neglected in clinical practice, and their diagnostic and prognostic implications remain elusive; the value of ECG to identify the culprit lesion has been investigated, but validated criteria indicating the presence of coronary occlusion in patients without ST-elevation are lacking; finally, which criteria among the multiple proposed, better define pathological Q-waves or success of revascularisation deserve further investigations.

METHODS

The Minimizing Adverse hemorrhagic events via TRansradial access site and systemic Implementation of AngioX (MATRIX) trial was designed to test the impact of bleeding avoidance strategies on ischemic and bleeding outcomes across the whole spectrum of patients with ACS receiving invasive management. The ECG-MATRIX is a pre-specified sub-study of the MATRIX programme which aims at analyzing the clinical value of ECG metrics in 4516 ACS patients (with and without ST-segment elevation in 2212 and 2304 cases, respectively) with matched pre and post-treatment ECGs.

CONCLUSIONS

This study represents a unique opportunity to further investigate the role of ECGs in the diagnosis and risk stratification of ACS patients with or without ST-segment deviation, as well as to assess whether the radial approach and bivalirudin may affect post-treatment ECG metrics and patterns in a large contemporary ACS population.

Differences in negative T waves among acute coronary syndrome, acute pulmonary embolism, and Takotsubo cardiomyopathy

AIMS

Negative T waves in precordial leads often occur in patients with acute coronary syndrome (ACS), but are also found in acute pulmonary embolism (APE) and Takotsubo cardiomyopathy (TC). Because the clinical features of these two diseases mimic those of ACS, differential diagnosis is essential to select an appropriate treatment strategy improve outcomes. This study aimed to clarify the differences in negative T waves among ACS, APE and TC.

METHODS AND RESULTS

We studied admission ECGs in 300 patients (198 patients with ACS caused by the left anterior descending coronary artery disease, 81 with APE and 21 with TC). All patients were admitted within 48 h from symptom onset and had negative T waves ≥1.0 mm without ST-segment elevation in leads V1 to V4. The number and maximal amplitude of negative T waves were greatest in patients with TC, followed by in those with ACS, and were lowest in patients with APE (p < 0.001, respectively). The prevalence of negative T waves significantly differed in all 12 leads among the three groups (p < 0.01, respectively). Negative T waves in both leads III and V1 identified APE with 90% sensitivity and 97% specificity. Negative T waves in lead -aVR (i.e., positive T waves in lead aVR) and no negative T waves in lead V1 identified TC with 95% sensitivity and 97% specificity. These values represented the highest diagnostic accuracies.

CONCLUSION

The distributions of negative T waves differed among ACS, APE and TC, and these differences were useful for differentiating among these three diseases.

Comparative prognostic value of T-wave inversion and ST-segment depression on the admission electrocardiogram in non-ST-segment elevation acute coronary syndromes

BACKGROUND

ST-segment depression (STD) is predictive of adverse outcomes in non-ST-segment elevation acute coronary syndromes (NSTE-ACS), but there are conflicting data on the incremental prognostic value of T-wave inversions (TWIs) on the admission electrocardiogram.

METHODS

Admission electrocardiograms of 7,343 patients with NSTE-ACS from the Global Registry of Acute Coronary Events (GRACE) and ACS I registry were independently analyzed at a core laboratory and stratified by TWI and STD status. We performed multivariable analyses to determine the independent prognostic significance of TWI and tested for interaction between TWI and STD for adverse outcomes.

RESULTS

Patients with TWI and/or STD had a higher prevalence of cardiovascular risk factors, higher Killip class, and higher GRACE risk scores. Among the 2,708 patients with available angiographic data, rates of 3-vessel or left main disease were similar between patients with TWI and those without TWI/STD. After adjusting for other established prognosticators, TWI did not independently predict in-hospital (adjusted odds ratio 1.03, 95% CI 0.75-1.42, P = .85) or 6-month mortality (adjusted odds ratio 1.02, 95% CI 0.80-1.30, P = .88); STD remained a strong independent predictor. There was no interaction between TWI and STD for these outcomes. No contiguous lead groups or cumulative number of leads with TWI provided independent prognostic information.

CONCLUSIONS

TWI is associated with other high-risk clinical features but is not an independent predictor of adverse short- and long-term mortality in NSTE-ACS. T-wave inversion does not provide additional prognostication beyond the GRACE risk model, and its concomitant presence does not alter the prognostic value of STD.

Usefulness of the admission electrocardiogram to predict long-term outcomes after non-ST-elevation acute coronary syndrome (from the FRISC II, ICTUS, and RITA-3 [FIR] Trials)

The aim of this study was to evaluate the independent prognostic value of qualitative and quantitative admission electrocardiographic (ECG) analysis regarding long-term outcomes after non-ST-segment elevation acute coronary syndromes (NSTE-ACS). From the Fragmin and Fast Revascularization During Instability in Coronary Artery Disease (FRISC II), Invasive Versus Conservative Treatment in Unstable Coronary Syndromes (ICTUS), and Randomized Intervention Trial of Unstable Angina 3 (RITA-3) patient-pooled database, 5,420 patients with NSTE-ACS with qualitative ECG data, of whom 2,901 had quantitative data, were included in this analysis. The main outcome was 5-year cardiovascular death or myocardial infarction. Hazard ratios (HRs) were calculated with Cox regression models, and adjustments were made for established outcome predictors. The additional discriminative value was assessed with the category-less net reclassification improvement and integrated discrimination improvement indexes. In the 5,420 patients, the presence of ST-segment depression (≥1 mm; adjusted HR 1.43, 95% confidence interval [CI] 1.25 to 1.63) and left bundle branch block (adjusted HR 1.64, 95% CI 1.18 to 2.28) were independently associated with long-term cardiovascular death or myocardial infarction. Risk increases were short and long term. On quantitative ECG analysis, cumulative ST-segment depression (≥5 mm; adjusted HR 1.34, 95% CI 1.05 to 1.70), the presence of left bundle branch block (adjusted HR 2.15, 95% CI 1.36 to 3.40) or ≥6 leads with inverse T waves (adjusted HR 1.22, 95% CI 0.97 to 1.55) was independently associated with long-term outcomes. No interaction was observed with treatment strategy. No improvements in net reclassification improvement and integrated discrimination improvement were observed after the addition of quantitative characteristics to a model including qualitative characteristics. In conclusion, in the FRISC II, ICTUS, and RITA-3 NSTE-ACS patient-pooled data set, admission ECG characteristics provided long-term prognostic value for cardiovascular death or myocardial infarction. Quantitative ECG characteristics provided no incremental discrimination compared to qualitative data.

Heritability of Tpeak-Tend interval and T-wave amplitude: a twin study

BACKGROUND

Tpeak-Tend interval (TpTe) and T-wave amplitude (Tamp) carry diagnostic and prognostic information regarding cardiac morbidity and mortality. Heart rate and QT interval are known to be heritable traits. The heritability of T-wave morphology parameters such as TpTe and Tamp is unknown. TpTe and Tamp were evaluated in a large sample of twins.

METHODS AND RESULTS

Twins from the GEMINAKAR study (611 pairs, 246 monozygotic, 365 dizygotic; mean age, 38±11 years; 49% men) who had an ECG performed during 1997 to 2000 were included. Tamp was measured in leads V1 and V5. Duration variables (RR interval, QTpeak and QTend interval) were measured and averaged over 3 consecutive beats in lead V5. TpTe was calculated as the QTend- and QTpeak-interval difference. Heritability was assessed using structural equation models adjusting for age, sex, and body mass index. All models were reducible to a model of additive genetics and unique environment. All variables had considerable genetic components. Adjusted heritability estimates were as follows: TpTe, 46%; Tamp lead V1, 34%; Tamp lead V5, 47%; RR interval, 55%; QT interval, 67%; and Bazett-corrected QT interval, 42%.

CONCLUSIONS

RR interval, QT interval, Tamp, and TpTe interval are heritable ECG parameters.

Prognostic implications of quantitative ST-segment characteristics and T-wave amplitude for cardiovascular mortality in a general population from the Health 2000 Survey

AIMS

We determined the gender-specific prognostic importance of quantitative measures of the ST segment and T wave in a community cohort.

METHODS

Data were collected from 5613 Finnish individuals. Four electrocardiogram (ECG) lead groups were used: anterior, lateral, inferior, and lead V5. ST-segment depression, determined at four points along the ST segment, and T-wave amplitude were treated as continuous variables in Cox regression analyses.

RESULTS

During a median follow-up period of 72.4 months, 120 cardiovascular deaths were registered. Among women, lateral lead group as well as lead V5 showed highly significant adjusted hazard ratios at all four ST-depression assessment points. This significance was lost in women ≥ 55 years when those with ECG-based criteria of left ventricular hypertrophy (LVH) were excluded. Results for ST-segment depression were not significant among men. As those with LVH were excluded, men ≥ 55 years showed borderline significance. T-wave amplitude did not reach significance among men, while lateral leads and lead V5 bore prognostic information among women.

CONCLUSION

Quantitative ST-segment depression, regardless of the measurement point, allows prediction of cardiovascular death in women within a general population. However, the effect disappears as those with LVH are excluded. This observation highlights the need for consideration of LVH when depressed ST segments are clinically observed.

Complementary prognostic values of ST segment deviation and Thrombolysis In Myocardial Infarction (TIMI) risk score in non-ST elevation acute coronary syndromes: Insights from the Platelet Receptor Inhibition in Ischemic Syndrome Management in Patients Limited by Unstable Signs and Symptoms (PRISM-PLUS) study

BACKGROUND

Although the Thrombolysis In Myocardial Infarction (TIMI) score incorporates ST deviation, it does not account for characteristics of the ST deviations. In the present study, it was hypothesized that the magnitude and characteristics of ST deviation may add to the prognostic values of the TIMI risk score in acute coronary syndrome (ACS) patients, particularly in lower-risk patients with a TIMI risk score of less than 5.

OBJECTIVE

To evaluate the prognostic value of combining the TIMI risk score and characteristics of ST deviation in patients with non-ST elevation ACS and a TIMI risk score of less than 5.

METHODS

The death/myocardial infarction (MI) rates of 1296 patients enrolled in the Platelet Receptor Inhibition in Ischemic Syndrome Management in Patients Limited by Unstable Signs and Symptoms (PRISM-PLUS) angiographic substudy were examined.

RESULTS

Patients without a TIMI risk score of 5 or greater, and without an ST deviation of 1 mm or greater had the lowest six-month rate of death/ MI (5%). In patients with a TIMI risk score of less than 5, the six-month death/MI rate was increased in those with ST depression of 2 mm or greater compared with patients with a similar TIMI risk score and without ST deviation of 1 mm or greater (24% versus 5%, P<0.001). The presence of ST deviation of 2 mm or greater identified an additional 15% of patients with an increased six-month death/MI rate in patients with a TIMI risk score of less than 5.

CONCLUSION

ST segment deviation of 2 mm or greater confers additional prognostic information in non-ST elevation ACS patients with a TIMI risk score of less than 5. Patients with a TIMI risk score of less than 5 and ST deviation of 2 mm or less had the lowest risk of six-month death/MI.

Significance of T-wave amplitude and dynamics at the time of reperfusion in patients with acute ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention

BACKGROUND

Peri-interventional T-wave changes may reflect the microvascular reperfusion status and potentially carry early independent, prognostic information in patients with ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI).

METHODS

The first available electrocardiogram (ECG) (index ECG) and the ECG recorded immediately post-PCI were analyzed for T-wave morphology in 207 patients with STEMI. Absolute T-wave amplitude was recorded and any change in T-wave amplitude from index ECG to post-PCI ECG was calculated. Continuous ST monitoring was performed from hospital arrival until 90 minutes after PCI. Maximum troponin level and left ventricular ejection fraction were evaluated before discharge. Final infarct size was assessed by myocardial perfusion imaging after 1 month.

RESULTS

Large, positive T-wave amplitude in the index ECG and the post-PCI ECG was associated with delayed ST resolution after PCI. In the post-PCI ECG, T-wave amplitude was positively associated with troponin-T value (P < .001) and final infarct size (P = .036), and inversely associated with left ventricular ejection fraction (P < .001). However, T-wave amplitude in the post-PCI ECG was also associated with procedural increase in ST elevation (P < .001) and inversely associated with spontaneous ST resolution (P < .017). A net decrease in T-wave amplitude during reperfusion therapy was associated with faster microvascular reperfusion as evaluated by time to ST resolution.

CONCLUSION

Large T-wave amplitudes in static pre- and post-PCI ECGs are associated with delayed microvascular reperfusion, whereas the dynamic development of more negative T waves during PCI is associated with earlier microvascular reperfusion. However, in the acute setting, T waves provide little incremental information when compared to ST parameters available in the per-interventional phase.

Predictive value of T-wave abnormalities at the time of emergency department presentation in patients with potential acute coronary syndromes

OBJECTIVES

T-wave abnormalities on electrocardiograms (ECGs) are common, but their ability to predict 30-day cardiovascular outcomes at the time of emergency department (ED) presentation is unknown. The authors determined the association between T-wave abnormalities on the presenting ECG and cardiovascular outcomes within 30 days of presentation in patients with potential acute coronary syndromes (ACSs).

METHODS

This was a secondary analysis of a prospective cohort study of ED patients that presented with a potential ACS. Patients were excluded if they had a prior myocardial infarction, ST-segment elevation or depressions, right or left bundle branch block, or Q-waves on the initial ECG. Data included demographics, medical and cardiac history, and ECG findings including the presence or absence of T-wave flattening, inversions of 1-5 mm, and inversions >5 mm. Investigators followed the hospital course for admitted patients, and 30-day follow-up was performed on all patients. The main outcome was a composite of death, acute myocardial infarction, revascularization, coronary stenosis greater than 50%, or a stress test with reversible ischemia.

RESULTS

Of 8,298 patient visits, 5,582 met criteria for inclusion: 4,166 (74.6%) had no T-wave abnormalities, 721 (12.9%) had T-wave flattening in two or more leads, 659 (11.8%) had T-wave inversions of 1-5 mm, and 36 (0.64%) had T-wave inversions >5 mm. The composite endpoint was more common in patients with T-wave flattening (8.2% vs. 5.7%; p = 0.0001; relative risk [RR] = 1.4; 95% confidence interval [CI] = 1.1 to 1.9), T-wave inversions 1-5 mm (13.2% vs. 5.7%; p = 0.0001; RR = 2.4; 95% CI = 1.8 to 3.1), and T-wave inversions >5 mm (19.4% vs. 5.7%; p = 0.0001; RR = 3.4; 95% CI = 1.7 to 6.1), or any T-wave abnormality (10.8% vs. 5.7%; p = 0.0001; RR = 1.9; 95% CI = 1.6 to 2.3), even after adjustment for initial troponin. This association also existed in the subset of patients without known coronary artery disease.

CONCLUSIONS

In patients with potential ACS presenting to the ED, T-wave abnormalities are associated with higher rates of 30-day cardiovascular events.

Usefulness of ST depression with T-wave inversion in leads V(4) to V(6) for predicting one-year mortality in non-ST-elevation acute coronary syndrome (from the Electrocardiographic Analysis of the Global Use of Strategies to Open Occluded Coronary Arteries IIB Trial)

ST-segment depression (ST-D) on the admission electrocardiogram of patients with non-ST-elevation acute coronary syndromes (NSTEACSs) is associated with higher mortality. However, few studies have evaluated the effect of location of ST-D and T-wave polarity on long-term prognosis of patients with NSTEACS. Electrocardiographic (ECG) and clinical data from 6,770 patients with NSTEACS randomly assigned in the Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO) IIB trial were analyzed retrospectively. One-year mortality was correlated with location of ST-D (leads I and aVL; II, III, and aVF; V1 to V3; or V4 to V6) and T-wave polarity. ST-D in any of the ECG locations was associated with higher mortality compared with patients without ST-D. Patients with ST-D and T-wave inversion in leads V4 to V6 had the highest 1-year mortality rate of all groups (16.2%), significantly higher compared with patients with ST-D without T-wave inversion in those leads (9.0%, p=0.001). Logistic regression analysis showed that age, hyperlipidemia, Killip class>I, history of myocardial infarction, history of heart failure, history of angina pectoris, systolic blood pressure, heart rate, sum of ST-D (odds ratio 1.061, 95% confidence interval 1.035 to 1.087, p<0.001), and ST-D with T-wave inversion in leads V4 to V6 (odds ratio 1.374, 95% CI 1.023 to 1.844, p=0.035) were independent predictors of 1-year mortality. Conversely, ST-D without T-wave inversion in leads V4 to V6 or other ECG presentations were not independent predictors of high 1-year mortality. In conclusion, ST-D with T-wave inversion in leads V4 to V6 on the admission electrocardiogram in patients with NSTEACS identifies those with higher 1-year mortality than for patients with any other ECG presentation.