Combining magnetic resonance viability variables better predicts improvement of myocardial function prior to percutaneous coronary intervention

Objective To optimize the predictive value of cardiac magnetic resonance imaging (MRI) for improvement of myocardial dysfunction prior to percutaneous coronary intervention (PCI). Methods We performed cardiac MRI in 72 patients (male 87%, age 60years) before and 6months after successful PCI (43/72) or unsuccessful PCI (29/72) of a chronic total coronary occlusion (CTO). Before PCI, 5 viability parameters were evaluated: transmural extent of infarction (TEI), contractile reserve during dobutamine, end diastolic wall thickness, unenhanced rim thickness and segmental wall thickening of the unenhanced rim (SWTur). Multivariate analysis was performed and based on the regression coefficient (RC) a predictive score was constructed. Diagnostic performance to predict improvement in myocardial function for each parameter and for the viability score was determined. Results The predictive value of a combination of contractile reserve, SWTur and TEI was incremental to TEI alone (AUROC 0.91 vs. 0.77; p<0.001). A viability score of ≥5 based on contractile reserve (RC=4), SWTur (RC=1) and TEI (RC=2) was 91% sensitive and 84% specific in predicting improvement of myocardial function. Conclusion Combining viability parameters results in a better prediction of improvement of dysfunctional myocardial segments after a successful PCI.