Myocardial Scar Identified by Magnetic Resonance Imaging Can Predict Left Ventricular Functional Improvement after Coronary Artery Bypass Grafting

Abstract

BackgroundPrevious studies have shown that viable myocardium predicts recovery of left ventricular (LV) dysfunction after revascularization. Our aim was to evaluate the prognostic value of myocardial scar assessed by late gadolinium-enhanced cardiovascular magnetic resonance imaging (LGE-CMR) on functional recovery in patients undergoing coronary artery bypass grafting (CABG).MethodsFrom November 2009 to September 2012, 63 patients with reduced left ventricular ejection fraction (LVEF) referred for first-time isolated CABG were prospectively enrolled, 52 were included in final analysis. LV functional parameters and scar tissue were assessed by LGE-CMR at baseline and 6 months after surgery. Patency of grafts was evaluated by computed tomography angiography (CTA) 6 months post-CABG. Predictors for global functional recovery were analyzed.ResultsThe baseline LVEF was 32.7±9.2%, which improved to 41.6±11.0% 6 months later and 32/52 patients improved LVEF by ≥5%. Multivariate logistic regression analysis showed that the most significant negative predictor for global functional recovery was the number of scar segments (Odds ratio 2.864, 95% Confidence Interval 1.172–6.996, p = 0.021). Receiver-Operator-Characteristic (ROC) analysis demonstrated that ≤4 scar segments predicted global functional recovery with a sensitivity and specificity of 85.0% and 87.5%, respectively (AUC = 0.91, p<0.001). Comparison of ROC curves also indicated that scar tissue was superior to viable myocardium in predicting cardiac functional recovery (p<0.001).ConclusionsOur findings indicated that scar tissue on LGE-CMR is an independent negative predictor of cardiac functional recovery in patients with impaired LV function undergoing CABG. These observations may be helpful for clinicians and cardiovascular surgeons to determine which patients are most likely to benefit from surgical revascularization.

Importance of baseline heart rate as a predictor of cardiac functional recovery in newly diagnosed heart failure with reduced ejection fraction

“…The presence of segmental wall‐motion abnormalities was a negative predictor of LVR. Scarring, fibrosis, and infarcted myocardium, as identified by various imaging modalities, have consistently shown to be negative predictors of functional recovery …”

Impact of Improved Left Ventricular Systolic Function on the Recurrence of Ventricular Arrhythmia in Heart Failure Patients With an Implantable Cardioverter‐Defibrillator

“…In this study, the extent of myocardial scarring was lower in the patients who presented with out-of-hospital cardiac arrest with VF than in those who presented with sustained monomorphic VT. Myocardial scarring is reportedly associated with functional nonrecovery from various conditions occurring after pharmacological or surgical treatments. [24][25][26] One plausible mechanism to explain why the HFrEF patients in our present population with an initial VF presentation were associated with late LVEF improvement was the presence of the lower extent of myocardial scarring. However, cardiac magnetic resonance imaging was not systemically performed in our present study patients.…”

Natural History and Implantable Cardioverter‐Defibrillator Implantation After Revascularization for Stable Coronary Artery Disease With Depressed Ejection Fraction

“…Yang demonstrated an absolute LVEF improvement of ≥5% in 32 of 52 (62%) patients with depressed LVEF after CABG, though only 58% of these patients had initial LVEF <35%. 11 Conflicting information in a similar population of patients with a depressed LVEF showed ''clinically significant'' LVEF improvement (again defined as a ≥5% increase) in only 39% of patients, and an average absolute improvement of only 3% (baseline 29 ± 7%, 32 ± 9% post-revascularization). 12 Of note, all these previously published data regarding LVEF response to revascularization refer to patients undergoing surgical revascularization.…”