Abstract 4168: Prediction of Global Left Ventricular Functional Recovery in Patients With Heart Failure Undergoing Surgical Revascularization, Based on the Number of Viable Segments Assessed by Late Gadolinium Enhancement Cardiovascular Magnetic Resonance
Background: The new gold standard for myocardial viability assessment is late gadolinium enhancement-cardiac magnetic resonance (LGE-CMR); this technique has demonstrated that the transmural extent of myocardial scar predicts segmental functional recovery. We now asked whether the number of viable segments predicted recovery of global left ventricular (LV) function in patients undergoing CABG. In addition, we examined which segmental transmural threshold of scarring best predicted global LV recovery.
Methods: Fifty patients with reduced LV ejection fraction (EF) referred for CABG were recruited, and 33 included in this analysis. Patients underwent CMR to assess LV function and viability pre-operatively, at 6 days and 6 months, based on a 16 segment model.
Results: Mean LVEF was 38%±11, which improved to 43%±12 after surgery. Importantly, 21/33 patients improved EF by at least 3% (EF before 38%±12, after 47%±13), while 12/33 did not (EF before 39%±6, after 37%±8). The only independent predictor for global functional recovery after revascularization was the total number of all viable segments (including those normally contracting segments): Based on a segmental transmural viability cutoff of <50%, ROC analysis demonstrated ≥10 viable segments predicted ≥3% improvement in LVEF with a sensitivity of 95% and specificity of 75% (AUC=0.9, p<0.001). Transmural viability cutoffs of <25 and <75% were less useful predictors of global LV recovery.
Conclusion: Based on a 50% transmural viability cutoff, patients with ≥10 viable segments improve global LV function post revascularization, while patients with fewer viable segments do not. LGE-CMR is a simple and powerful tool for identifying which coronary artery disease patients with impaired LV function will benefit from CABG.