Head to head comparison of quantitative versus visual analysis of contrast CMR in the setting of myocardial stunning after STEMI: implications on late systolic function and patient outcome.

To compare a quantitative assessment of contrast cardiovascular magnetic resonance (CMR) after ST-segment elevation myocardial infarction (STEMI) with visual analysis for predicting depressed ejection fraction (dEF) and major adverse cardiac events (MACE). 192 patients underwent CMR at 1 week and 6 months after STEMI. Three quantitative (initial slope, maximal signal intensity and contrast delay in first-pass imaging) and 2 visual perfusion indexes (hypoenhancement in first-pass and microvascular obstruction in late enhancement imaging (LE)) were determined. Quantification of infarct mass and visual assessment of the extent of transmural necrosis (ETN) were also performed. At 6 months, 69 patients displayed dEF. During follow-up (mean 655 days) 20 MACE (death, re-infarction, re-admission for heart failure) occurred. Perfusion quantification took longer (P < 0.001) and, in ROC curve analyses and the C-statistic, was not superior to visual perfusion analysis for predicting late EF or MACE (P = ns). Similarly, infarct size quantification was not superior to visual assessment of ETN (P = ns). In multivariate analyses, only visual assessment of ETN (per segment) predicted dEF (OR 1.30 95%CI [1.04-1.61], P = 0.02) and MACE (HR 1.38 95%CI [1.19-1.60], P < 0.001). Visual analysis of CMR after STEMI is not time consuming and predicts dEF and MACE comparable to quantification. ETN was the strongest parameter.