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Acute ST-segment elevation myocardial infarction requires prompt restoration of myocardial perfusion to salvage myocardium at risk of ischemic necrosis and improve clinical outcome. Early resolution of ST-segment elevation during the time after reperfusion has been associated with both these end points. From the ASsessment of the Safety and Efficacy of a New Thrombolytic regimen (ASSENT) 3 trial, 3,425 patients were analyzed to investigate whether the amount of ST-segment resolution, divided into 3 groups (complete, >70%; partial, 30% to 70%; and no resolution, <30%), in the first hour after initiation of therapy was a predictor of final infarct size, estimated by peak creatine kinase and Selvester QRS score on the discharge electrocardiogram. Complete compared with partial and no ST resolution resulted in significantly (p <0.001) smaller infarct sizes of 10.5%, 13.2%, and 15.0% of the left ventricle and significantly (p = 0.001) fewer patients with peak creatine >5 times the upper reference level at 50.3%, 71.8%, and 76.3%, respectively. In conclusion, our findings supported previous smaller studies suggesting that early resolution of ST elevation, as a sign of early myocardial reperfusion, resulted in less myocardial damage and preservation of left ventricular function. [Copyright &y& Elsevier]

We compared combination fibrinolytic plus glycoprotein IIb/IIIa inhibitor therapy with stand-alone fibrinolysis with respect to speed and stability of reperfusion in patients who had acute ST-segment elevation myocardial infarction; data were obtained from 654 patients in 4 trials (Integrilin to Manage Platelet Aggregation to Combat Thrombosis in Acute Myocardial Infarction, Platelet Aggregation Receptor Antagonist Dose Investigation and Reperfusion Gain in Myocardial Infarction, Integrilin and Tenecteplase in Acute Myocardial Infarction, and the Fifth Global Use of Strategies to Open Occluded Coronary Arteries) that compared thrombolytics plus lamifiban, eptifibatide, or abciximab with standard thrombolysis. We found significantly faster and more stable ST-segment recovery with combination therapy starting at 60 minutes (56.7% vs 48.0% with ≥50% ST-segment resolution, p = 0.03) and sustained over 180 minutes after drug administration; this transient benefit may suggest a time frame when more optimal percutaneous coronary intervention can be performed. [Copyright &y& Elsevier]

In patients with ST-segment elevation myocardial infarction treated with fibrinolytics, electrocardiogram-derived measures of ST-segment recovery guide therapy decisions and predict infarct size. The comprehension of these relationships in patients undergoing mechanical reperfusion is limited. We studied 144 patients treated with primary percutaneous coronary intervention. We aimed to define the association between infarct size as determined by cardiac magnetic resonance imaging and different metrics of ST-segment recovery. Electrocardiograms were assessed at baseline and 90 minutes after primary percutaneous coronary intervention. Three methods for calculating and categorizing ST-segment recovery were used: (1) summed ST-segment deviation (STD) resolution analyzed in 3 categories (≥70%, ≥30% to <70%, and <30%); (2) single-lead STD resolution analyzed in the same 3 categories; (3) worst-lead residual STD analyzed in 3 categories (<1 mm, 1 to <2 mm, and ≥2 mm). Infarct size and ejection fraction were assessed at 4 months by cardiac magnetic resonance imaging. All 3 ST-segment recovery algorithms predicted the final infarct size and cardiac function. Worst-lead residual STD performed the same as, or better than, the more complex methods and identified large subgroups at either end of the risk spectrum (median infarct size from the lowest to highest risk category (percentage of left ventricle: 7.7% [interquartile range 10.8], 13.1% [interquartile range 13.6]; 24.6% [interquartile range 21.1]); with adjusted odds ratios for infarct size greater than the median (reference <1 mm): 1 to <2 mm, odds ratio 2.3 (95% confidence interval 0.8 to 5.9); ≥2 mm, odds ratio 6.3 (95% confidence interval 1.7 to 23.7; c-index 0.781). In conclusion, an electrocardiogram obtained early after primary percutaneous coronary intervention analyzed by a simple algorithm provided prognostic information on the final infarct size and cardiac function. [Copyright &y& Elsevier]

Twelve-lead ST-segment monitoring is a widely used tool for capturing focal ischemia and transient intermittent episodes. However, continuous registration of all 10 electrodes is impractical in clinical settings. This study investigated the accuracy of 2 derived 12-lead strategies that required 6 electrodes, including all limb leads, and 2 precordial leads by using population-based (generalized) and individualized (patient-specific) reconstruction coefficients to derive the additional 4 chest leads. A total of 26,880 simultaneous digital conventional 12-lead generalized and patient-specific electrocardiograms were monitored over 112 hours in 39 patients during percutaneous coronary intervention, including 159 balloon occlusions in 63 arteries, to test accuracy at rest and during ischemia. Occlusion duration was 78 seconds (range 42 to 96) in the left main coronary in 2 patients, the left anterior descending artery in 15, the right coronary artery in 10, the circumflex artery in 2, and graft segments in 5 patients. Average summated 12-lead ST deviation over the study population at baseline was 377 μV (range 104 to 1,718), which increased at peak ischemia to an average of 1,086 μV (range 282 to 4,099). Median absolute differences at peak ischemic ST deviation were 25 μV in lead V1, 0 μV in lead V2, 35 μV in lead V3, 34 μV in lead V4, 0 μV in lead V5, 11 μV in lead V6, and 114 μV for summated 12-lead ST deviation with the generalized method and 7 μV in lead V1, 4 μV in lead V2, 1 μV in lead V3, 5μV in lead V4, 4 μV in lead V5, 9 μV in lead V6, and 83 μV for the summated 12-lead ST deviation with the patient-specific method. Limb leads (I, II, III, aVR, aVL, and aVF) were identical in all patients. Thus, generalized and patient-specific methods derived from 12-lead electrocardiography using actual limb and 2 precordial electrodes accurately derived the additional chest leads at rest and during ischemia. These approaches appear to be more practical than conventional 10-electrode monitoring but preserve high accuracy. [Copyright &y& Elsevier]