Direct measurement of atrioventricular valve regurgitant jets using 4D flow CMR accurately measured regurgitant fraction compared to the clinical standard volumetric method, with a median difference of -1.5%.
Cohort (n=44)
Blinded analysis
No
Does direct measurement of atrioventricular valve regurgitation using 4D flow CMR provide accurate and reliable results compared to the standard volumetric method in pediatric patients with congenital heart disease?
Direct measurement of atrioventricular valve regurgitation using 4D flow CMR is an accurate and reliable alternative to the standard 2D CMR volumetric method in pediatric congenital heart disease.
Effect estimate: Median difference -1.5% (95% CI -8.3-7.2)
p-value: p=0.624
BACKGROUND: 3D-time resolved flow (4DF) cardiovascular magnetic resonance (CMR) with retrospective analysis of atrioventricular valve regurgitation (AVVR) allows for internal validation by multiple direct and indirect methods. Limited data exist on direct measurement of AVVR by 4DF CMR in pediatric congenital heart disease (CHD). We aimed to validate direct measurement of the AVVR jet as accurate and reliable compared to the volumetric method (clinical standard by 2D CMR) and as a superior method of internal validation than the annular inflow method. METHODS: We identified 44 consecutive patients with diverse CHD referred for evaluation of AVVR by CMR. 1.5 T or 3 T scanners, intravenous contrast, and a combination of parallel imaging and compressed sensing were used. Four methods of measuring AVVR volume (RVol) were used: volumetric method (VOL; the clinical standard) = stroke volume by 2D balanced steady-state free precession - semilunar valve forward flow (SLFF); annular inflow method (AIM) = atrioventricular valve forward flow AVFF - semilunar valve net flow (SLNF); and direct measurement (JET). AVFF was measured using static and retrospective valve tracking planes. SLFF, SLNF, AVFF, and JET were measured by 4DF phase contrast. Regurgitant fraction was calculated as RVol/(RVol+SLNF)× 100. Statistical methods included Spearman, Wilcoxon rank sum test/Student paired t-test, Bland Altman analysis, and intra-class coefficient (ICC), where appropriate. RESULTS: Regurgitant fraction by JET strongly correlated with the indirect methods (VOL and AIM) (ρ = 0.73-0.80, p < 0.001) and was similar to VOL with a median difference (interquartile range) of - 1.5% (- 8.3-7.2%; p = 0.624). VOL had weaker correlations with AIM and JET (ρ = 0.69-0.73, p < 0.001). AIM underestimated RF by 3.6-6.9% compared to VOL and JET, p < 0.03. Intra- and inter- observer reliability were excellent for all methods (ICC 0.94-0.99). The mean (±standard deviation) inter-observer difference for VOL was 2.4% (±5.1%), p < 0.05. CONCLUSIONS: In a diverse cohort of pediatric CHD, measurement of AVVR using JET is accurate and reliable to VOL and is a superior method of internal validation compared to AIM. This study supports use of 4DF CMR for measurement of AVVR, obviating need for expert prospective prescription during image acquisition by 2D CMR.
Jacobs et al. (Wed,) conducted a cohort in Congenital heart disease with atrioventricular valve regurgitation (n=44). Direct measurement of atrioventricular valve regurgitant jets (JET) using 4D flow CMR vs. Volumetric method (VOL) and annular inflow method (AIM) was evaluated on Regurgitant fraction measured by JET compared to VOL (Median difference -1.5%, 95% CI -8.3-7.2, p=0.624). Direct measurement of atrioventricular valve regurgitant jets using 4D flow CMR accurately measured regurgitant fraction compared to the clinical standard volumetric method, with a median difference of -1.5%.