Usefulness of a New Transthoracic Echocardiography Score to Assess Right Ventricular Volumes in Patients with Repaired Tetralogy of Fallot.

Quantification of right ventricular (RV) volumes is essential in the follow-up of patients with a repaired tetralogy of Fallot (TOF). Cardiac magnetic resonance imaging (MRI) is the gold standard for RV assessment. However, given its cost and availability, the systematic use of MRI for serial longitudinal follow-up is limited. Herein, we examined the utility of a new two-dimensional (2D) transthoracic echocardiography (TTE) score (the RVDi score), which includes a compilation of 2D RV dimensions indexed to the body surface area, for predicting MRI-derived RV end-diastolic volume (RVEDV) in patients with a repaired TOF. Using our congenital heart clinic database, we retrospectively included 29 adult patients with a repaired TOF between February 2015 and July 2019. The 2D TTE RVDi score was compared with the MRI-derived RVEDV. Sensitivity and specificity values for predicting an RVEDVi > 150 ml/m2 were calculated. The TTE RVDi score was highly correlated (r = 0.944) with MRI RVEDVi. A cut-off RVDi score set at 120 mm/m2 predicted an RVEDVi > 150 ml/m2 with a sensitivity of 83% and specificity of 94%. Use of a simple echocardiographic score based on indexed RV dimensions from 2D standard TTE imaging may complement the assessment of RV volumes in TOF patients.

Clinical outcomes after primary prevention defibrillator implantation are better predicted when the left ventricular ejection fraction is assessed by cardiovascular magnetic resonance.

BACKGROUND: The left ventricular ejection fraction (LVEF) is the key selection criterion for an implanted cardioverter defibrillator (ICD) in primary prevention of sudden cardiac death. LVEF is usually assessed by two-dimensional echocardiography, but cardiovascular magnetic resonance (CMR) imaging is increasingly used. The aim of our study was to evaluate whether LVEF assessment using CMR imaging (CMR-LVEF) or two-dimensional echocardiography (2D echo-LVEF) may predict differently the occurrence of clinical outcomes. METHODS: In this retrospective study, we reviewed patients referred for primary prevention ICD implantation to Caen University Hospital from 2005 to 2014. We included 173 patients with either ischemic (n = 120) or dilated cardiomyopathy (n = 53) and who had undergone pre-ICD CMR imaging. The primary composite end point was the time to death from any cause or first appropriate device therapy. RESULTS: The mean CMR-LVEF was significantly lower than the mean 2D echo-LVEF (24% ± 6 vs 28% ± 6, respectively; p < 0.001). CMR-LVEF was a better independent predictive factor for the occurrence of the primary composite endpoint with a cut-off value of 22% (Hazard Ratio [HR] = 2.22; 95% CI [1.34-3.69]; p = 0.002) than 2D echo-LVEF with a cut-off value of 26% (HR = 1.61; 95% CI [0.99-2.61]; p = 0.056). Combination of the presence of scar with CMR-LVEF< 22% improved the predictive value for the occurrence of the primary outcome (HR = 2.58; 95% CI [1.54-4.30]; p < 0.001). The overall survival was higher among patients with CMR-LVEF≥22% than among patients with CMR-LVEF< 22% (p = 0.026), whereas 2D echo-LVEF was not associated with death. CONCLUSIONS: CMR-LVEF is better associated with clinical outcomes than 2D echo-LVEF in primary prevention using an ICD. Scar identification further improved the outcome prediction. The combination of CMR imaging and echocardiography should be encouraged in addition to other risk markers to better select patients.