Relationship between ST-segment resolution and anterior infarct size after primary percutaneous coronary intervention: analysis from the INFUSE-AMI trial

Abstract

Aims: ST-segment resolution (STR) after reperfusion therapy has been shown to correlate with prognosis in patients with ST-segment elevation myocardial infarction (STEMI). We investigated whether acute ECG measurements also correlate with ultimate infarct size. Methods and Results:The INFUSE-AMI trial randomized 452 patients with anterior STEMI to intracoronary bolus abciximab vs. no abciximab, and to thrombus aspiration vs. no aspiration. Infarct size as percentage of total LV mass was calculated by cardiac magnetic resonance imaging (MRI) 30 days post intervention. Five ECG methods were analysed for their ability to predict MRI infarct mass: (1) summed STR across all infarct-related ECG leads (ΣSTR); (2) STR in the single lead with maximum baseline ST-segment elevation (maxSTR); (3) summed residual ST-segment elevation across all infarct-related leads at 60 min post intervention (ΣST residual); (4) maximum residual ST-segment elevation in the worst single lead at 60 min post intervention (maxST residual); (5) number of new significant Q-waves (Qwave) at 60 min. All ECG methods strongly correlated with 30-day MRI infarct mass (all p<0.003). Simpler ECG measurements such as maxSTresidual and Qwave were as predictive as more complex measurements. A subset analysis of 158 patients who had microvascular obstruction (MVO) determined by MRI 5 days post intervention also showed strong correlations of MVO with the ECG measures. Conclusions: ST-segment and Q-wave changes after primary PCI in anterior STEMI strongly correlated with 30-day infarct size by MRI. In particular, maxST residual and Qwave at 60 min are simple ECG parameters that offer rapid analysis for prognostication.

Impact of Early ST-Segment Changes on Cardiac Magnetic Resonance-Verified Intramyocardial Haemorrhage and Microvascular Obstruction in ST-Elevation Myocardial Infarction Patients

“…Previous studies showed that poor STR is a good predictor of poor microvascular flow recovery and inferior clinical outcomes. 15 , 16 This was also confirmed by our findings that patients with CMR-MVO had worsened STR than those without MVO. In the meanwhile, we found that STE (ie, maximal STE and sum STE) was also correlated with MVO.…”

“…ST-segment changes are better indicators for myocardial rather than epicardial flow, thus help to enhance prognostic value of coronary angiography alone. 15 – 18 Several studies have suggested that a simple serial electrocardiogram (ECG) analysis could be very helpful to identify MVO in patients with STEMI treated with PCI. 19 – 22 However, the relationship between different parameters of ST-segment change and IMH still remains to be clarified and which parameter is the most practicable predictor for detecting cardiac magnetic resonance(CMR)-derived MVO or IMH is conflicting.…”

The impact of epicardial adipose tissue in patients with acute myocardial infarction

“…These findings are supported by the association of EAT with MVO and ST-deviation. Both parameters mirroring disturbed microcirculation [ 32 ], correlate with infarct size [ 30 , 33 ].…”

<p>Biomarkers in acute myocardial infarction: current perspectives</p>

“…However, the majority of cases without ST-segment elevation develop unstable angina pectoris or AMI without a Q wave, with a few developing AMI with a Q wave. ST-segment elevation changes into ST-segment depression when an oxygen-free environment persists 8…”