Echocardiography-Derived Hemodynamic Forces in Cardiac Resynchronization Therapy: Association with Reverse Remodeling and Long-Term Outcomes

BACKGROUND: Cardiac resynchronization therapy (CRT) improves survival and symptoms in patients with heart failure with reduced ejection fraction and electromechanical dyssynchrony, yet up to 30% to 40% do not respond despite guideline-based selection. Hemodynamic forces (HDFs) quantify intraventricular pressure gradients and can be derived from routine echocardiographic images. The aim of this study was to assess the predictive and prognostic value of HDF parameters in patients undergoing CRT and to investigate changes in HDF after CRT implantation. METHODS: The following HDF parameters were assessed in 198 patients from the multicenter, prospective MARC study: (1) apical-basal force, (2) latero-septal force, (3) their ratio, (4) force vector angle, (5) systolic apical-basal force, and (6) systolic angle. Cardiac resynchronization therapy response was defined as ≥15% reduction in left ventricular end-systolic volume at 6 months. The composite outcome of all-cause mortality or cardiovascular hospitalization was analyzed using Cox regression models with long-term follow-up. RESULTS: A total of 120 patients (60.6%) demonstrated echocardiographic response to CRT at 6 months. The addition of baseline systolic angle to clinical, electrocardiographic, and conventional echocardiographic markers of dyssynchrony significantly improved model fit for CRT response, although discrimination was not significantly improved. Responders showed significant improvement in HDF parameters after CRT, whereas no significant changes were observed in nonresponders. During a median follow-up of 9.3 years, baseline systolic angle was independently associated with the composite endpoint of all-cause mortality or cardiovascular hospitalization and significantly improved risk stratification when added to established prognostic markers. CONCLUSION: Hemodynamic force parameters provide complementary descriptive insight into ventricular mechanics in patients undergoing CRT. Baseline systolic angle was independently associated with both reverse remodeling and long-term outcome, although discrimination was not significantly improved. Although these findings suggest potential value for HDF assessment, further research is warranted to determine the clinical relevance in CRT patients.