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Background: Using a comprehensive ST-segment-elevation myocardial infarction registry, we evaluated the relationships of baseline Q waves, time from symptom onset, and reperfusion strategy with in-hospital clinical outcomes., Methods and Results: Consecutive ST-segment-elevation myocardial infarction patients from a defined health region were classified by the presence of baseline Q waves and additionally into primary percutaneous coronary intervention, fibrinolysis, or no reperfusion. ECGs were collected at baseline, after reperfusion, and analyzed for the presence of Q waves using Selvester criteria. Among 2290 ST-segment-elevation myocardial infarction patients, 36.9% had Q waves on their baseline ECG. Patients with Q waves were older (median age, 59 versus 57), were more often male (82.0% versus 75.4%), had higher heart rate (80 versus 72), had higher Global Registry of Acute Coronary Events risk score (129 versus 127), and were with longer time to reperfusion (42 minutes longer). They had higher composite end points (16.3% versus 10.0%), consistent across times from symptom onset to presentation (15.4% versus 9.9% ≤3 hours; 18.5% versus 8.9% >3 to ≤6 hours; 15.9% versus 11.3% >6 hours; Q and no Q, respectively). Baseline Q waves, but not time to reperfusion, were associated with an increased odds of the in-hospital composite end point of death, congestive heart failure, cardiogenic shock, and reinfarction (adjusted odds ratio, 1.65; 95% confidence interval, 1.18-2.30; P =0.003). Type of reperfusion did not modify the association of baseline Q waves and in-hospital outcomes ( P interaction=0.918)., Conclusions: The presence of baseline Q waves, rather than time to treatment, was significantly associated with adverse in-hospital events in real-world patients, regardless of reperfusion strategy used., (© 2017 American Heart Association, Inc.)

Objective: Uncertainty exists concerning the relative merits of pharmacological versus mechanical coronary reperfusion in patients presenting early with ST-elevation myocardial infarction (STEMI) with extensive myocardium at risk. Accordingly, we investigated whether the extent of baseline ST-segment shift was related to the response of either reperfusion modality in patients with STEMI presenting within 3 h of symptoms., Methods: We analysed baseline ECGs from 1859 patients enrolled in the STrategic Reperfusion Early After Myocardial Infarction (STREAM) trial. The sum of ST-segment elevation (∑STE) and ST-segment deviation (∑STD) was categorised into quartiles and associations with the primary endpoint (30-day death/shock/congestive heart failure/re-myocardial infarction) for each reperfusion strategy (early fibrinolysis vs primary percutaneous coronary intervention) were explored., Results: Overall, there was a progressive rise in the 30-day primary endpoint according to quartiles of baseline ∑STE (10.3% (0-5 mm), 12.4% (5.5-8.5 mm), 12.1% (9-13.5 mm), 17.6% (> 14.0 mm), p = 0.008) and ∑STD (9.0% (0-9 mm), 13.5% (9.5-14 mm), 14.7% (14.5-20 mm), 15.3% (> 20 mm), p = 0.019). Both ∑STE and ∑STD were associated with the primary endpoint (∑STE: p = 0.071; ∑STD: p = 0.024). However, there was no interaction between quartiles of baseline ∑STE or ∑STD and efficacy of either reperfusion strategy on the 30-day clinical outcomes (∑STE: p (interaction) = 0.696; ∑STD: p (interaction) = 0.542)., Conclusions: These data demonstrate an association between ∑STE or ∑STD on the baseline ECG and clinical events at 30 days following reperfusion therapy in STEMI. More importantly, the response to different reperfusion strategies was not influenced by the extent of jeopardised myocardium., Trial Registration Number: NCT00623623; Post-results., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background: The prognostic value of time from symptom onset to reperfusion may be enhanced by the identification of Q waves on the presenting electrocardiogram (ECG) in patients with ST-segment elevation myocardial infarction (STEMI). We evaluated whether the relative prognostic utility of these 2 metrics was altered by sex., Methods: Q waves in the distribution of the ST-segment elevation on the baseline ECG were evaluated by a blinded core laboratory in 2838 STEMI patients (2163 men and 675 women) from the PLATelet inhibition and patient Outcomes (PLATO) trial who underwent percutaneous coronary intervention (PCI) within 12 hours of symptom onset., Results: Women were older (median 63 vs 57 years), more likely to be diabetic (24.1% vs 15.5%), hypertensive (69.2% vs 50.9%), and a higher Killip class > I (8.6% vs 5.9%), as compared with men. Whereas the Q waves frequency rose progressively over time to ECG in men, this relationship was attenuated in women (P = .057). Q waves on the baseline ECG were associated with a higher excess hazard of 1-year vascular death in men (hazard ratio [HR] 2.03; 95% confidence interval [CI], 1.13-3.72), and a similar trend existed in women (HR 1.97; 95% CI, 0.86-4.51). Women with baseline Q waves tended to have higher risk of 1-year vascular death than men as continuous time from symptom onset to PCI increased (P[interaction] = .182)., Conclusions: These differences in the evolution of baseline Q waves and relationship between time from symptom onset and vascular death in women and men deserve recognition in future studies of STEMI., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objectives: To evaluate quantitative relationships between baseline Q-wave width and 90-day outcomes in ST-segment elevation myocardial infarction (STEMI)., Background: Baseline Q-waves are useful in predicting clinical outcomes after MI., Methods: 3589 STEMI patients were assessed from a multi-centre study., Results: 1156 patients of the overall cohort had pathologic Q-waves. The 90-day mortality and the composite of mortality, congestive heart failure (CHF), or cardiogenic shock (p<0.001 for both outcomes) rose as Q-wave width increased. After adapting a threshold ≥40ms for inferior and ≥20ms for lateral/apical MI in all patients (n=3065) with any measureable Q-wave we found hazard ratios (HR) for mortality (HR: 2.44, 95% confidence interval (CI) (1.54-3.85), p<0.001) and the composite (HR: 2.32, 95% CI (1.70-3.16), p<0.001). This improved reclassification of patients experiencing the composite endpoint versus the conventional definition (net reclassification index (NRI): 0.23, 95% CI (0.09-0.36), p<0.001) and universal MI definition (NRI: 0.15, 95% CI (0.02-0.29), p=0.027)., Conclusions: The width of the baseline Q-wave in STEMI adds prognostic value in predicting 90-day clinical outcomes. A threshold of ≥40ms in inferior and ≥20ms for lateral/apical MI enhances prognostic insight beyond current criteria., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Objectives: We evaluated inter-reader agreement of the ST-segment between two electrocardiogram (ECG) core laboratories., Background: Accurate measurement of the ST-segment is key to diagnosis and management of acute coronary syndromes (ACS). Clinical trials also rely on adherence to the pre-specified ECG eligibility criteria., Methods: 150 patients (100 ST-segment elevation (STE)-ACS, 50 non-STE-ACS) were selected. An experienced ECG reader from each laboratory measured ST-segment deviation on the baseline ECGs (nearest 0.1mm)., Results: ∑ST-segment deviation showed excellent inter-reader agreement (R=0.965, intraclass correlation coefficient (ICC) 0.949, 95% CI (0.930-0.963)). Similar agreement was observed when ∑ST-segment elevation (∑STE) and ∑ST-segment depression (∑STD) were assessed separately. Better agreement was evident in STE-ACS cohort (ICC (95% CI): 0.968 (0.953-0.978, 0.969 (0.954-0.979), 0.931 (0.899-0.953)) compared to NSTE-ACS patients (ICC (95% CI): 0.860 (0.768-0.917), 0.816 (0.699-0.890), 0.753 (0.605-0.851) across measurement of ∑ST-segment deviation, ∑STE, and ∑STD., Conclusions: We demonstrated excellent agreement on ST-segment measurements between two experienced readers from two ECG core laboratories., (© 2013.)

Background: Baseline Q waves may provide additional value compared with time from the onset of symptoms in predicting outcomes for patients with ST-segment elevation. We evaluated whether baseline Q waves superseded time from symptom onset as a prognostic marker of one-year mortality in patients with ST-segment elevation acute coronary syndrome. Our study was derived from data from patients undergoing primary percutaneous coronary intervention within 24 hours in the PLATelet inhibition and patient Outcomes trial, Methods: Q waves on the baseline electrocardiogram were evaluated by a blinded core laboratory. We assessed the associations between baseline Q waves and time from symptom onset to percutaneous coronary intervention with peak biomarkers, ST-segment resolution on the discharge electrocardiogram, and one-year all-cause and vascular mortality., Results: Of 4341 patients with ST-segment elevation, 46% had baseline Q waves. Compared to those without Q waves, those with baseline Q waves were older, more frequently male, had higher heart rates, more advanced Killip class and had a longer time between the onset of symptoms and percutaneous coronary intervention. They also had higher one-year all-cause mortality than patients without baseline Q waves (baseline Q waves: 4.9%; no baseline Q waves: 2.8%; hazard ratio [HR] 1.78, 95% confidence interval [CI] 1.29-2.45, p < 0.001). Complete ST-segment resolution was greatest and all-cause mortality lowest among those with symptom onset three hours or less before percutaneous coronary intervention and no baseline Q waves. After multivariable adjustment, baseline Q waves, but not time from symptom onset, were associated with a significant increase in all-cause mortality (adjusted HR 1.42, 95% CI 1.10-2.01, p = 0.046) and vascular mortality (adjusted HR 1.58, 95% CI 1.09-2.28, p = 0.02)., Interpretation: The presence of baseline Q waves provides useful additional prognostic insight into the clinical outcome of patients with ST-segment elevation. Clinical Trials.gov registration no. NCT00391872.