Assessment of Asymptomatic Severe Aortic Regurgitation by Doppler-Derived Echo Indices: Comparison with Magnetic Resonance Quantification.

Reliable quantification of aortic regurgitation (AR) severity is essential for clinical management. We aimed to compare quantitative and indirect echo-Doppler indices to quantitative cardiac magnetic resonance (CMR) parameters in asymptomatic chronic severe AR. Methods and Results: We evaluated 104 consecutive patients using echocardiography and CMR. A comprehensive 2D, 3D, and Doppler echocardiography was performed. The CMR was used to quantify regurgitation fraction (RF) and volume (RV) using the phase-contrast velocity mapping technique. Concordant grading of AR severity with both techniques was observed in 77 (74%) patients. Correlation between RV and RF as assessed by echocardiography and CMR was relatively good (rs = 0.50 for RV, rs = 0.40 for RF, p < 0.0001). The best correlation between indirect echo-Doppler and CMR parameters was found for diastolic flow reversal (DFR) velocity in descending aorta (rs = 0.62 for RV, rs = 0.50 for RF, p < 0.0001) and 3D vena contracta area (VCA) (rs = 0.48 for RV, rs = 0.38 for RF, p < 0.0001). Using receiver operating characteristic analysis, the largest area under curve (AUC) to predict severe AR by CMR RV was observed for DFR velocity (AUC = 0.79). DFR velocity of 19.5 cm/s provided 78% sensitivity and 80% specificity. The AUC for 3D VCA to predict severe AR by CMR RV was 0.73, with optimal cut-off of 26 mm2 (sensitivity 80% and specificity 66%). Conclusions: Out of the indirect echo-Doppler indices of AR severity, DFR velocity in descending aorta and 3D vena contracta area showed the best correlation with CMR-derived RV and RF in patients with chronic severe AR.

New Imaging Markers of Clinical Outcome in Asymptomatic Patients with Severe Aortic Regurgitation.

Background: Determining the value of new imaging markers to predict aortic valve (AV) surgery in asymptomatic patients with severe aortic regurgitation (AR) in a prospective, observational, multicenter study. Methods: Consecutive patients with chronic severe AR were enrolled between 2015-2018. Baseline examination included echocardiography (ECHO) with 2- and 3-dimensional (2D and 3D) vena contracta area (VCA), and magnetic resonance imaging (MRI) with regurgitant volume (RV) and fraction (RF) analyzed in CoreLab. Results: The mean follow-up was 587 days (interquartile range (IQR) 296-901) in a total of 104 patients. Twenty patients underwent AV surgery. Baseline clinical and laboratory data did not differ between surgically and medically treated patients. Surgically treated patients had larger left ventricular (LV) dimension, end-diastolic volume (all p < 0.05), and the LV ejection fraction was similar. The surgical group showed higher prevalence of severe AR (70% vs. 40%, p = 0.02). Out of all imaging markers 3D VCA, MRI-derived RV and RF were identified as the strongest independent predictors of AV surgery (all p < 0.001). Conclusions: Parameters related to LV morphology and function showed moderate accuracy to identify patients in need of early AV surgery at the early stage of the disease. 3D ECHO-derived VCA and MRI-derived RV and RF showed high accuracy and excellent sensitivity to identify patients in need of early surgery.

Cardiac resynchronization therapy guided by cardiac magnetic resonance imaging: A prospective, single-centre randomized study (CMR-CRT).

BACKGROUND: Cardiac resynchronization therapy (CRT) improves symptoms of heart failure (HF), morbidity and mortality in selected population. The aim of the study was to investigate the impact of cardiac magnetic resonance (CMR)-guided left ventricular (LV) lead placement on clinical outcomes and LV reverse remodelling in CRT recipients. METHODS: Patients with CRT indication were randomized for CMR-guided (CMR group) or electrophysiologically guided (EP group) LV lead placement between 2011 and 2014. The target site in the CMR group was defined as the most delayed, scar-free, in the EP group as the site with the longest interval between the QRS onset and local electrogram. The primary endpoint was a combination of cardiovascular death or HF hospitalization. Secondary endpoints were New York Heart Association (NYHA) Class improvement ≥1, LV endsystolic diameter reduction >10%, B-type natriuretic peptide reduction by ≥30%. RESULTS: A total of 99 patients (47 in the CMR and 52 in the EP group) were enrolled. During a median follow-up of 47 months, primary composite endpoint occurred in 5 patients in the CMR group and 14 patients in the EP group (HR = 0.46; 95% CI: 0.16-1.32). Patients with left bundle branch block and NYHA Class >2 had better clinical outcome in the CMR group (HR = 0.09; 95% CI: 0.01-0.75). CONCLUSIONS: The use of CMR did not result in significant reduction of combined endpoint of cardiovascular death or HF hospitalization in the total study population. Significant clinical benefit from CMR-guided procedure was observed in a subgroup of optimum CRT candidates with advanced HF.