Aortic regurgitation and left ventricle remodeling in cardiac magnetic resonance and transthoracic echocardiography

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Medical University of SIlesia Background Transthoracic echocardiography (TTE) is the main imaging modality used to assess patients with chronic aortic regurgitation (AR). However, it is not possible to provide a precise quantification in all patients. Our aim was to compare TTE and cardiovascular magnetic resonance (CMR) measurements in grading AR and left ventricle (LV) remodeling. Methods A total of 51 consecutive patients with isolated AR in TTE were enrolled into the study and finally forty nine individuals (age: 57.1 (14); 61% males) underwent a non-contrast CMR (2 pts excluded for CMR contraindications). AR severity grading and LV remodeling were assessed according to the current ASE guidelines, including a semi-quantitative and quantitative parameters. All CMR studies were obtained on ecg-gated cine images acquired on 1.5T system (GE Optima MR450w, GE Healthcare, Wisconsin, USA) with a dedicated cardiac coil using a non-contrast protocol, including a quantitative approach (phase-contrast velocity encoded imaging). Results Most of the study patients showed mild symptoms (NYHA I/II/III – 55%/38%/7%; CCS 0/I/II/III/IV – 79%/2%/12%/6%) and typical cardiovascular risk factors: hypertension (83%), dyslipidemia (91%), diabetes (12%) and obesity (16%). Twenty patients (40%) showed combined AV disease and 14 patients (28,5%) had a bicuspid AV. The AR jets were central (53%) or eccentric (47%) and multiple in 7 cases (14%). The inter-modality agreement (TTE-CMR) in AR grading was high in mild AR (91%) and low in mild-to-moderate (12%), moderate-to-severe (10%) and severe (20%) AR. The comprehensive quantitative grading with AR volume (AR vol) and regurgitant fraction (RF) were measurable in TTE in 24 cases and showed a significant association with CMR parameters (AR vol: r = 0.75; p < 0.001 and RF: r = 0.55; p < 0.01). Moreover, CMR revealed significantly larger LV end-diastolic volumes (EDV) (185,5 ± 61ml vs 158,4 ± 61ml; p = 0.03) and a trend towards higher left ventricle ejection fraction (59 ± 8 vs 56 ± 8%; p = 0.08). The association of AR vol and LV EDV was stronger in CMR (r = 0.85; p < 0.0001) compared to TTE (r = 0.6; p = 0.001). Conclusions CMR provides a comprehensive assessment of AR severity and LV remodeling with a moderate agreement with TTE.