Predicting late myocardial recovery and outcomes in the early hours of ST-segment elevation myocardial infarction : traditional measures compared with microvascular obstruction, salvaged myocardium, and necrosis characteristics by cardiovascular magnetic resonance

Objectives : The aim of this study was to determine whether a very early imaging strategy improves the prediction of late systolic dysfunction and poor outcomes in ST-segment elevation myocardial infarction (STEMI) compared with traditional predictors. Background : Earlier prediction of poor outcomes after STEMI is desirable, because it will allow tailored therapy at the earliest possible time, when benefits might be greatest. Methods : One hundred and three patients with acute STEMI were studied by contrast-enhanced cardiovascular magnetic resonance within 12 h of primary angioplasty and at 6 months and followed >2 years. The primary end point was left ventricular (LV) dysfunction, whereas poor outcomes were a key secondary end point. Results : Traditional risk factors were only modest predictors of late LV dysfunction. Late gadolinium enhancement (LGE) volume maintained a stronger association to LV ejection fraction change than infarct transmurality, microvascular obstruction, or myocardial salvage during STEMI (p = 0.02). Multivariable logistic regression identified LGE volume during STEMI as the best predictor of late LV dysfunction (odds ratio: 1.36, p = 0.03). An LGE =23% of LV during STEMI accurately predicted late LV dysfunction (sensitivity 89%, specificity 74%). The LGE volume provided important incremental benefit for predicting late dysfunction (area under the curve = 0.92, p = 0.03 vs. traditional risk factors). Twenty-three patients developed poor outcomes (1 death, 2 myocardial infarctions, 5 malignant arrhythmias, 4 severe LV dysfunction <35%, 11 hospital stays for heart failure) over 2.6 ± 0.9 years; LGE volume remained a strong independent predictor of poor outcomes, whereas LGE =23% carried a hazard ratio of 6.1 for adverse events (p < 0.0001). Conclusions : During the hyperacute phase of STEMI, LGE volume provides the strongest association and incremental predictive value for late systolic dysfunction and discerns poor late outcomes