P608Exercise testing and multi-parametric CMR assessment in patients with Ebstein anomaly

Abstract

Abstract Background Ebstein anomaly (EA) is a rare congenital heart disease characterized by an apically displaced tricuspid valve. It is associated with tricuspid valve regurgitation and right heart dilatation leading to significant morbidity. While echocardiography remains the mainstay of routine outpatient cardiac imaging, assessment of right ventricular (RV) anatomy and function is still challenging. Cardiovascular magnetic resonance imaging (CMR) has been shown to be of advantage in these patients being free from acoustic window limitations and offering superior volume quantification. In the present study, parameters obtained from cardiopulmonary exercise testing (CPET) were compared to conventional and novel CMR parameters in patients with EA. Methods In this prospective single centre study, N=17 patients with EA (mean age = 33.8±12.7yrs; N=10 females) underwent clinical assessment, CPET and multi-parametric CMR. Maximal work load (maxWL) and peak oxygen uptake (maxO2) were derived from CPET. CMR studies were performed on a 1.5-T Philips scanner and respective CMR parameters comprised a) anatomical, b) functional and c) myocardial deformation values of both ventricles. Results The majority of patients presented in NYHA class I or II (mean NYHA = 1.6±0.7) and with normal or mildly elevated NT-proBNP values (mean NT-proBNP = 189±158pg/ml). CPET-based maxWL was 147.14±55 watts and maxO2 19.32±5 ml/kg/min. CMR-based mean LVEF was 57.1±6.4% and RVEF was 46.5±11.1%, respectively. Deformation imaging revealed (amongst others) a LV global longitudinal strain (LV-gLS) of −13.7±3.0 and a RV global longitudinal strain (RV-gLS) of −14.7±5.0. Non-ischemic presence of late-gadolinium-enhancement was documented in 36% of our patients. Comprehensive correlation analysis revealed a substantial correlation a) between LV-gLS and NYHA class (r=0.64, p=0.01), but not between RV-gLS and NYHA class (r=0.19, p=0.46), b) between serum NT-proBNP levels and maxO2 (r=−0.53, p=0.03) as well as maxWL (r=−0.63, p=0.02), and c) between LV-EF and LV-gLS (r=−0.64, p=0.01). Conclusion Our preliminary data suggest that serum markers such as NT-proBNP and novel CMR parameters such as LV-gLS – but not RV-gLS - correlate with CPET-derived exercise parameters in patients with EA. The predictive value of these parameters regarding cardiac disease progression in EA has to be evaluated in future follow-up studies.