Abstract 10335: Systolic Motion of the Basal Right Ventricular Freewall is the Strongest Predictor of Global Function: A High Resolution 3D Cardiac Magnetic Resonance Study
Background: Right ventricular (RV) function has prognostic value in disease cohorts and the general population although its complex geometry and motion make rapid assessment difficult. Several two-dimensional regional measures are used to estimate global RV function, however the optimal measure is not known.
Methods: High-resolution 3-dimensional cardiac magnetic resonance (3D-CMR) cine imaging of the whole heart was acquired in 300 healthy volunteers and a computational model of RV motion created. From this model, points where regional function was significantly associated with global function were identified, and a two-dimensional, Optimized Single-Point Marker (SPM-O) of global function developed. This marker was prospectively compared with tricuspid annular plane systolic excursion (TAPSE), septum-freewall displacement (SFD) and their fractional derivatives (TAPSE-F, SFD-F) in a test cohort (n=300). Performance in predicting RVEF was compared by correlation, bootstrapped linear regression and mean absolute error.
Results: Three-dimensional imaging suggested that RVEF was significantly associated with systolic function in a contiguous 7.3cm2 patch of the basal RV freewall which combined components of transverse (38%), longitudinal (35%) and circumferential (27%) contraction. SPM-O was identified where this patch coincided with the four-chamber view and combined longitudinal and transverse contraction. In the test cohort, all single-point surrogates correlated with RVEF (p<0.01), but correlation was significantly higher for SPM-O (R = 0.44) than TAPSE (R = 0.24, p<0.002) and SFD (R = 0.22, p<0.001), and non-significantly higher than TAPSE-F (R = 0.40, p=0.50) and SFD-F (R = 0.43, p=0.86). SPM-O explained more of the observed variance in RVEF (19%) and predicted RVEF more accurately than any other 2D marker (median error 2.8 vs 3.6%, p<0.001).
Conclusions: Systolic motion of the basal RV freewall in the four-chamber plane is a more accurate surrogate of global function than other two-dimensional estimators. However, the performance of two-dimensional estimators is fundamentally limited by a failure to adequately summarize three-dimensional contractile patterns, such as those found in the right ventricle.
Author Disclosures: T. Dawes: None. A. de Marvao: None. W. Shi: None. D. Rueckert: None. S. Cook: None. D.P. O'Regan: None.
- © 2015 by American Heart Association, Inc.