Cardiovascular magnetic resonance validation of fractional changes in annulo-apical angles and tricuspid annular plane systolic excursion for rapid assessment of right ventricular systolic function.

ABSTRACT

PURPOSE: To evaluate the use of right ventricular (RV) annulo-apical angle (AA) changes acquired by magnetic resonance imaging (MRI), alongside tricuspid annular plane systolic excursion (TAPSE), for its association with RV systolic function. MATERIALS AND METHODS: Thirty patients with varying RV dysfunction and 10 normal controls were enrolled and scanned after obtaining written consent. Systolic change in AAs, alpha (α), beta (ß), and theta (θ), subtended by a triangle connecting the septal and lateral extent of the tricuspid valve annulus and RV apex, and TAPSE were measured. Spearman rank correlations of parameters with RV ejection fraction (RVEF) were performed. Receiver operating characteristic (ROC) analysis was used to determine accuracy of these surrogate markers for detecting abnormal RVEF. RESULTS: Correlations with RVEF included TAPSE (r = 0.74 P < 0.001), fractional systolic changes in α angle (0.64, P < 0.001), ß angle (-0.39, P < 0.05), and θ angle (-0.77, P < 0.001). The best markers for RVEF <50% were fractional θ angle change ≥ -25.5% (eg, -24%) (sensitivity of 97% and specificity of 91%), and TAPSE ≤1.87 cm (sensitivity of 100% and specificity of 82%). Intra- and inter-observer agreement was excellent, with intraclass correlation coefficients for fractional θ angle change (intra = 0.96, inter = 0.94) and TAPSE (intra = 0.98, inter = 0.87). CONCLUSION: Fractional θ angle change is a useful semiquantitative parameter associated with the presence and severity of RV systolic dysfunction, with high observer agreement.