Association of echocardiography-derived hemodynamic force parameters with left ventricular reverse remodeling after cardiac resynchronization in non-ischemic cardiomyopathy

Abstract

Abstract Background Cardiac resynchronization therapy (CRT) improves outcome in selected heart failure patients and can induce left ventricular (LV) reverse remodeling. Echocardiography-derived hemodynamic forces (HDF) are a new clinical tool which provides insight in fluid dynamics. Purpose To evaluate whether baseline HDF parameters are associated with LV reverse remodeling at six months after CRT implantation in patients with non-ischemic cardiomyopathy. Methods From a CRT database, patients with LV ejection fraction <35%, QRS duration >130ms and left bundle branch block were included. At baseline, the following HDF parameters were measured for the complete heart cycle (Figure 1): 1) apical-basal strength, representing the magnitude of the longitudinal HDF, 2) lateral-septal strength, representing the magnitude of the transversal HDF and 3) the angle, representing the HDF orientation. In the systolic thrust (i.e. the positive part of systole in the apical-basal curve), the apical-basal impulse (AB impulse) and the systolic angle were measured. LV reverse remodeling was defined as a reduction of LV end-systolic volume ≥15% at six months. Results In total, 196 patients were included (age 64±11 years, 62% male). LV reverse remodeling was observed in 136 (69%) patients (i.e. responders). Baseline characteristics are presented in Table 1. Responders had a higher angle in the complete heart cycle (67.1 vs 64.1; p = 0.002) as compared to non-responders, indicating less deviation of HDF orientation in responders. Responders also had a higher AB impulse (5.0% vs. 3.4%, p = 0.012) and higher systolic angle (74.0 vs. 71.0), p<0.001), indicating larger magnitude of HDF and less deviation of HDF orientation in the systolic thrust. Univariable logistic regression showed a significant association of loop diuretic use, LV global longitudinal strain (LV GLS), left atrial volume index (LAVI), the angle, AB impulse and the systolic angle with LV reverse remodeling. To minimize collinearity, two multivariable models were built. Loop diuretic use, LV GLS, LAVI and AB impulse were inserted in both models, while the angle was inserted in the first model and the systolic angle in the second model. In the first model, the angle (HR 1.082 (95%CI 1.018, 1.150), p = 0.011) was independently associated with LV reverse remodeling while the systolic angle (HR 1.073 (95%CI 1.011, 1.140), p = 0.021) was independently associated with LV reverse remodeling in the second model. Conclusion At baseline, responders have better orientation of HDF in the complete heart cycle and larger magnitude and better orientation of HDF in the systolic thrust as compared to non-responders. The orientation of HDF in the complete heart cycle and systolic thrust is independently associated with LV reverse remodeling. As such, the angle and systolic angle of HDF have the potential to identify patients that are likely to experience LV reverse remodeling after CRT.Figure 1.HDF in non-ischemic CMPTable 1.Baseline characteristics