BACKGROUND

Previous studies demonstrated that scar tissue assessed by late gadolinium enhancement cardiovascular magnetic resonance imaging (LGE-CMR) is associated with recovery of cardiac function after coronary artery bypass graft (CABG) in patients with a history of myocardial infarction (MI). However, information on the association between myocardial scar at baseline and long-term survival after CABG in these patients is lacking.

METHODS

From April 2010 to May 2013, consecutive patients with multivessel coronary artery disease (CAD, > 70% stenosis in ≥2 vessels) and MI (> 3 months) who underwent LGE-CMR within 1 month prior to isolated CABG were enrolled. Left ventricular functional parameters and scar tissue were assessed by LGE-CMR before surgery. A standard 17-segment model was used for scar quantification. Predictors for cardiovascular events (CVEs) were analyzed.

RESULTS

Of 148 patients who met the study inclusion/exclusion criteria, 140 cases had follow-up data and were included in final analysis. Of the latter, 27 (19.3%) patients suffered CVEs perioperatively or during mean 89.6 ± 12.0 months follow-up. In Cox proportional hazard regression model, the most significant predictor for CVEs after CABG was the number of scar segments on LGE-CMR (Hazard ratio 2.078, 95% Confidence Interval 1.133-3.814, P= 0.018). In Receiver-Operator-Characteristic (ROC) analysis, number of scar segments ≥6 predicted CVEs (sensitivity, 74.1%; specificity, 95.6%; area under the curve [AUC] = 0.934, P < 0.001).

CONCLUSIONS

Scar tissue identified by LGE-CMR appears to be an independent predictor of CVEs after CABG in patients with a history of MI, which might allow preoperative risk stratification.