Prediction of mitral regurgitation resolution after coronary bypass graft surgery and cardiac resynchronization therapy by late gadolinium enhancement magnetic resonance imaging: A case report

Abstract

Background Appropriate surgical management of moderate functional mitral regurgitation (MR) at the time of coronary artery bypass graft (CABG) surgery remains controversial. A recent study demonstrated no survival benefit from adding mitral repair to CABG for patients with moderate functional MR. Preoperative prediction of reverse remodelling is crucial in making the decision to add mitral valve repair to CABG. Late gadolinium-enhanced magnetic resonance imaging (LGE MRI) offers a reference method to assess myocardial viability. Case summary A 60-year-old man with ischaemic cardiomyopathy was admitted to our hospital with exacerbation of heart failure symptoms. Left ventricular (LV) dilatation, severe impairment of LV systolic function, and moderate MR due to tethering were noted on transthoracic echocardiography. The mitral regurgitant jet was central. Intravenous administration of furosemide and human atrial natriuretic peptide was initiated. The patient experienced an episode of ventricular tachycardia, and coronary angiography demonstrated triple-vessel disease. On LGE MRI, subendocardial infarction with a transmural extent of 25-50% was revealed in the inferior, posterior, and lateral walls. Findings from LGE MRI suggested that myocardial viability had been preserved. After performing CABG and cardiac resynchronization therapy, LV volume was substantially decreased and moderate MR was significantly improved without surgical mitral repair. On speckle tracking echocardiography before surgery, a significant difference in the times to peak radial strain between the lateral wall (462 ms) and inferior wall (17 ms) indicated the presence of LV dyssynchrony. Left ventricular dyssynchrony was substantially improved after CABG and cardiac resynchronization therapy defibrillator implantation. Discussion In patients with ischaemic cardiomyopathy and moderate functional MR, acquisition of LGE MRI of the LV should be considered to evaluate the viability of LV myocardium. Findings from LGE MRI of the LV can potentially influence the surgical strategy. In patients with preserved viability of LV myocardium, functional MR could be improved after CABG without any surgical repair.