083 Annulo-apical angles and tapse to rapidly assess right ventricular systolic function: a cardiac magnetic resonance study

• Published in: Heart (British Cardiac Society) Vol. 98; no. Suppl 1; pp. A46 - A47
• Main Authors: Zakeri, S A, Borg, A N, Schmitt, M
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd and British Cardiovascular Society 01.05.2012; BMJ Publishing Group LTD
• Subjects: annulo-apical angle; right ventricular ejection fraction; Tricuspid annulus peak systolic excursion
• ISSN: 1355-6037; 1468-201X
• DOI: 10.1136/heartjnl-2012-301877b.83

BackgroundVolumetric assessment of the right ventricle (RV) by Cardiac Magnetic Resonance (CMR), albeit time-consuming, provides accurate and reproducible measurement of RV ejection fraction (RVEF). Tricuspid annulus peak systolic excursion (TAPSE) is a predominantly Echo-validated rapidly—derived surrogate of RV function. Correlations between RVEF and systolic changes in annulo-apical angles (AAAs) have not previously been evaluated.ObjectiveTo assess the use of changes in AAAs and TAPSE as rapidly-derived surrogate markers of RV systolic function using CMR.MethodsWe measured RV volumes from short-axis bSSFP stacks in patients undergoing clinically indicated CMR scans. RVEF was calculated from volumes derived by semi-automated endocardial contouring (QMass®MR 7.2). AAAs (α, β, θ angles—see Abstract 083 figure 1), subtended by a triangle connecting the medial and lateral extent of the tricuspid valve annulus and RV apex, and fractional changes in AAAs (ΔAAA/EDAAA×100, whereby ΔAAA=EDAAA−ESAAA) were measured from end-diastolic (ED) and end-systolic (ES) 4chamber SSFP cine still frames. TAPSE was measured as the change in length of a line connecting the lateral tricuspid valve annulus with the RV apex from ED to ES. Parameters were compared with RVEF using Spearman rank correlations; ROC curves constructed to assess accuracy of the parameters in predicting an RVEF<50%.Abstract 083 Figure 1Top: AAAs in ED on a 4 chamber view. Bottom: ROC curve analysis.Results40 subjects were included: 10 normals, 10 mildly-impaired, 10 moderately-impaired, and 10 with severely-impaired RV systolic function. Median (25th–75th percentile) RVEF for each subgroup was 53.5% (51.4%–55.7%), 41.5% (38.1%–47.2%), 30.0% (21.7%–33.5%), and 15.8% (9.6%–21.2%), respectively. Correlations with RVEF: TAPSE (0.74, p<0.001), fractional changes of α angle (0.64, p<0.001), β angle (–0.39, p<0.05), and θ angle, which had the highest correlation (–0.77, p<0.001). Smaller increases or a decrease in magnitude of the θ angle from ED to ES are associated with lower RVEFs, whereby a fractional θ angle change of ≥ –25.5% predicts RVEF<50% [97% sensitivity, 91% specificity, AUC=0.98]. The cut-off for TAPSE is ≤1.87 cm [100% sensitivity, 82% specificity, AUC=0.98]. Intra- and inter-observer reproducibility is excellent as shown by intra-class correlation coefficients for TAPSE (0.98 and 0.87, respectively) and fractional θ angle change (0.96 and 0.94, respectively).ConclusionBoth fractional θ angle change and TAPSE strongly correlate with RVEF, and are accurate predictors of RVEF<50%. These measurements provide an excellent alternative to the more time-consuming derivation of RVEF obtained volumetrically by endocardial chamber tracing.Abstract 083 Figure 2Scatter graphs for fractional θ angle change and TAPSE, both plotted against RVEF. Dotted vertical lines represent the ROC cut-offs of RVEF<50%. Dashed horizontal lines represent cut-offs of ≥ –25.5% and ≤1.87 cm for fractional θ angle change and TAPSE, respectively.