Myocardial Fibrosis Identified by Cardiac Magnetic Resonance Late Gadolinium Enhancement Is Associated With Adverse Ventricular Mechanics and Ventricular Tachycardia Late After Fontan Operation

Abstract

Objectives To evaluate the relationship between myocardial fibrosis identified by cardiac magnetic resonance (CMR) and ventricular performance and arrhythmias in patients late after the Fontan operation. Background Patients who have undergone the Fontan palliation may develop ventricular dysfunction and arrhythmias, but the mechanisms and risk factors are poorly defined. Methods All patients who have had a Fontan operation and a CMR study with the myocardial delayed enhancement technique from January 2002 to November 2008 were retrospectively identified. Results Of 90 patients (mean age at study 23.1 ± 10.9 years), 25 (28%) had positive late gadolinium enhancement (LGE) in the ventricular myocardium. Patients with positive LGE had lower mean ejection fraction (EF) (45% v. 56%, P<0.001), increased median end-diastolic volume (EDVi) (100 mL/BSA1.3 v. 82 mL/BSA1.3, P=0.004), increased median ventricular massi (63 g/BSA1.3 v. 45 g/BSA1.3, P<0.001), higher frequency of regional wall motion abnormalities (52% v. 28%, P=0.05), and higher frequency of non-sustained ventricular tachycardia (NSVT) (36% v. 11%, P=0.01). Multivariate regression analysis demonstrated that more extensive positive LGE, expressed as percent LGE of total myocardial mass, was associated with lower EF (P=0.002), increased EDVi (P<0.001), increased massi (P<0.001), and a higher frequency of NSVT (OR 1.2, 95% CI 1.1 to 1.4, P=0.006). Conclusions In this cohort of late Fontan survivors, myocardial fibrosis was common and associated with adverse ventricular mechanics and higher prevalence of NSVT. Further studies are warranted to examine the utility of LGE for risk stratification and treatment of ventricular arrhythmia and dysfunction in Fontan patients.

Three-Dimensional Mechanical Dyssynchrony and Myocardial Deformation of the Left Ventricle in Patients with Tricuspid Atresia after Fontan Procedure

“…Recently, in vivo evidence of myocardial fibrosis in Fontan patients has been provided by late gadolinium enhancement (LGE) cardiac magnetic resonance, which showed a higher prevalence of LGE involving the systemic ventricular free wall than the septum. 28 Indeed, associations between LGE and regional wall motion abnormalities and dyskinesia reported in the aforementioned study corroborate our finding of a relationship between cIB and SDI. It is noteworthy, however, that alteration of fiber structure, orientation, and contractile performance may also affect cIB intensity.…”

Role of cardiac MRI and CT in Fontan circulation

“…Areas of scar appear bright on delayed enhancement imaging due to slower extra-cellular gadolinium contrast clearance kinetics in scar tissue. Recently, the presence and extent of delayed enhancement in the myocardium correlated with regional and global ventricular dysfunction as well as non-sustained ventricular tachycardia in these patients [35].…”

Chronic Heart Failure in Congenital Heart Disease

“…This method has been used to demonstrate macroscopic areas of fibrosis in several different CHD subgroups, including TOF (53%), 71 systemic RV (61%), 72 Eisenmenger syndrome (73%), 73 and Fontan palliation (26%). 74 Collectively, these studies demonstrate that the presence of LGE is associated with poorer functional class, lower ventricular systolic function, reduced exercise capacity, and arrhythmia, although the quantity of enhancement is often small and sparse (apart from less common large subendocardial infarcts or surgical scars).…”