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AFI is clinically applicable and an effective means of assessing LV function due to its short acquisition time, feasibility and accuracy, whatever the experience of the operator.

Purpose: To determine the prognostic significance of systolic wall stress (SWS) after reperfused acute myocardial infarction (AMI) using MRI. Materials and Methods:A total of 105 patients underwent MRI 7.8 Ϯ 4.2 days after AMI reperfusion. SWS was calculated by using a three-dimensional (3D) MRI approach to left ventricular (LV) wall thickness and to the radius of curvature. Between hospital discharge and the end of follow-up, an average of 4.1 Ϯ 1.7 years after AMI, 19 patients experienced a major cardiac event, including cardiac death, nonfatal reinfarction or heart failure (18.3%). Results:The results were mainly driven by heart failure outcome. In univariate analysis the following factors were predictive of postdischarge major adverse cardiac events: 1) at the time of AMI: higher heart rate, previous calcium antagonist treatment, in-hospital congestive heart failure, proximal left anterior descending artery (LAD) occlusion, a lower ejection fraction, higher maximal ST segment elevation before reperfusion, and ST segment reduction lower than 50% after reperfusion; 2) MRI parameters: higher LV end-systolic volume, lower ejection fraction, higher global SWS, higher SWS in the infarcted area (SWS MI) and higher SWS in the remote myocardium (SWS remote). In the final multivariate model, only SWS MI (odds ratio [OR]: 1.62; 95% confidence interval [CI]: 1.01-2.60; P ϭ 0.046) and SWS remote (OR: 2.17; 95% CI: 1.02-4.65; P ϭ 0.046) were independent predictors. Conclusion:Regional SWS assessed by means of MRI a few days after AMI appears to be strong predictor of postdischarge cardiac events, identifying a subset of at risk patients who could qualify for more aggressive management. DESPITE ADVANCES IN acute reperfusion therapy and medical treatments, including angiotensin-convertingenzyme (ACE) inhibitors and ␤-blockers, extensive acute myocardial infarction (AMI) often causes progressive left ventricular (LV) volume enlargement and a gradual deterioration of cardiac function. Elongation and thinning of the infarcted myocardium occurs immediately after coronary occlusion (1,2), whereas expansion of the remote myocardium continues even after the initial infarct has healed (3-5). Natural history studies show that progressive LV remodeling is directly related to future deterioration of LV performance and to a less favorable clinical course after AMI (6 -8). LV wall stress is thought to be responsible for these morphological changes that occur in both infarcted and noninfarcted areas (9 -13). LV wall stress is the product of LV pressure and a geometric factor dependent on the shape of the left ventricle (14,15). Because of the difficulty of measuring regional wall stress after AMI in the complex geometry of the infarcted heart, the long-term prognostic significance of wall stress in the infarct area and in remote myocardium has not yet been analyzed.Offering three-dimensional (3D) images with high spatial resolution, without the need for geometric assumptions, magnetic resonance imaging (MRI) is the tool of choice for pre...

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