Clinical Implications of Serial Changes in ST-Segment Elevation After Reperfusion in Patients With Anterior Acute Myocardial Infarction

Abstract

he main goals of reperfusion therapy for acute myocardial infarction (AMI) are early, sustained patency of the infarct-related artery (IRA) and optimal microvascular reperfusion. [1][2][3][4][5][6] Recent studies have shown that resolution of ST-segment elevation (ST resolution) on the 12-lead electrocardiogram (ECG) after reperfusion is associated with adequate microvascular perfusion in AMI and may predict smaller infarct size, better left ventricular (LV) function, and better outcomes. 7-10 However, we previously reported that some patients have a larger infarct size, LV dysfunction, and inadequate myocardial perfusion despite ST resolution, suggesting that ST resolution does not consistently predict myocardial salvage. 11 Moreover, Brodie et al reported a poorer correlation between ST resolution and late cardiac mortality in anterior myocardial infarction (MI) than in the non-anterior type. 12 To clarify the clinical significance of ST resolution in more detailed, we examined the relationship between ST-segment changes up to 24 h after reperfusion and LV function in patients with reperfused anterior wall AMI. Circulation Journal Vol.72, March 2008 Methods Study PopulationWe studied 164 consecutive patients (mean age 62±11 years, range 30-86; 134 men, 30 women) with anterior AMI who were admitted to hospital and fulfilled the following criteria: (1) reperfusion (defined as restoration of Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow) of the left anterior descending artery within 6 h of symptom onset and persistent patency of the IRA at a mean of 14 days and 6 months as confirmed by coronary angiography (CAG); (2) absence of conditions precluding the evaluation of ST-segment changes on ECG (eg, left or right bundle branch block, ventricular pacing); (3) ECG recorded on admission and at 1 h and 24 h after reperfusion; (4) absence of cardiogenic shock on admission. Patients with a re-elevation of serum creatine kinase (CK) (ie, re-infarction) during hospitalization were also excluded, because re-occlusion of the IRA could cause recurrent ST-segment elevation. The diagnosis of AMI was based on typical chest pain lasting ≥30 min, ST-segment elevation ≥2.0 mm in ≥2 contiguous precordial leads, and a typical increase in the serum CK level to more than twice the upper limit of normal. Pre-infarction angina was defined as the presence of typical chest pain occurring at rest or during exercise and persisting for less than 30 min within 24 h of the onset of AMI. 13 The protocol was approved by the hospital's internal review board and all patients gave informed consent. Background In patients with acute myocardial infarction (AMI), the relationship of serial changes in STsegment elevation after reperfusion to left ventricular (LV) function remains unclear. Methods and ResultsThe study group comprised 164 patients with reperfused anterior AMI within 6 h of symptom onset. The sum of ST-segment deviation was calculated on admission (∑ST-admission), and 1 h (∑ST-1 h) and 24 h (∑ST-24 h) after reperfusion. ST reso...

Incidence and Significance of Spontaneous ST Segment Re-elevation After Reperfused Anterior Acute Myocardial Infarction ― Relationship With Infarct Size, Adverse Remodeling, and Events at 1 Year―

“…In contrast, the results are not consistent with those reported by Okuda et al, 12 who found ST segment reelevation was associated with larger infarct size and poorer LVEF at 6 months. Okuda et al 12 even showed that ST segment re-elevation (after initial ST resolution) was worse than the absence of initial ST segment resolution.…”

“…There are few data regarding the significance of ST segment reelevation after reperfusion, with most data coming from small clinical studies that were performed before the PPCI reperfusion era. [10][11][12][13][14] In these small studies, the results are discordant, suggesting either increased severity in myocardial injury, 10 increased infarct size and poorer LV functional outcomes, 11,12 subclinical pericarditis, 13 or no significant effect on LV functional outcomes. 14 Moreover, there have been no studies examining the relationship between ST segment re-elevation and clinical outcomes.…”

“…Several clinical situations have been associated with ST segment reelevation, including subclinical pericarditis, 13 reinfarction or stent thrombosis, infarct expansion, 35 reperfusion injury, or an intense inflammatory response. 12 Zmyslinski et al 13 described ST segment re-elevation by ECG mapping in large groups of STEMI patients and found that its incidence was higher in case of pericarditis. The incidence of manifest pericarditis and stent thrombosis during the initial hospitalization did not differ between the 2 groups in the present study.…”

Presence of myocardial hypoenhancement on multidetector computed tomography after primary percutaneous coronary intervention in acute myocardial infarction predicts poor prognosis

“…Previous studies found that infarct regions are larger in patients without ST resolution upon electrocardiography, leading to decreased left ventricular function [13,14]. Based on those findings, we defined ST resolution on admission and immediately after PCI; the sum of ST segment deviation was calculated on admission (ΣST-admission), before PCI (ΣST-before-PCI), and soon after PCI (ΣST-after-PCI).…”

ST-segment re-elevation following primary angioplasty in acute myocardial infarction with patent infarct-related artery: impact on left ventricular function recovery and remodeling

“…It was found that ST-segment re-elevation (reSTE) following primary PCI observed in one fifth of patients with anterior STEMI with an occluded IRA on initial contrast injection was not associated with increased infarct size, left ventricular (LV) function or clinical outcomes at 1 year [9,10]. In contrast, lack of ST-segment resolution or reSTE within 24 h following PCI was associated with increased enzymatic injury and reduced LV function [11]. Moreover, in STEMI patients, microvascular obstruction and intramyocardial hemorrhage were more frequently observed in contrast-enhanced cardiac magnetic resonance of patients with reSTE during primary PCI [12].…”