Left Ventricular Myocardial Work for Predicting Response to Cardiac Resynchronization Therapy (CRT): A Multi-Center Study

This study aims to establish the normal reference values for left ventricular myocardial work in healthy Chinese adults and the influencing factors. Non-invasive myocardial work serves as a new parameter for identifying CRT responders and provides a scoring system for predicting the efficacy of CRT in clinical practice. CRT can improve cardiac function and quality of life, and reduce mortality and hospitalization rates due to heart failure (HF). Currently, the number of CRT treatments is increasing year by year, but even when strictly following the indications, approximately 30% of patients do not respond. Therefore, precise prediction of CRT efficacy is of great clinical significance for improving prognosis. Currently, the indications for CRT mainly rely on clinical, electrocardiogram (CLBBB), and LVEF. By correcting ventricular contraction asynchrony to improve systolic function, however, CLBBB indicates electrical asynchrony, and LVEF improvement depends on mechanical synchrony. If the mechanical asynchrony of the ventricles can be evaluated directly before surgery, it will help predict the efficacy of CRT. Myocardial work is a recently developed non-invasive method that combines LV afterload with the overall longitudinal strain (GLS) analysis of echocardiography. Myocardial work reflects the contraction ability of the heart, stroke work, residual myocardial contraction ability, myocardial oxygen consumption, useless work, useful work, etc., and is represented by the pressure-volume loop analysis, thus having the potential to predict the efficacy of CRT. Therefore, this study intends to adopt the left ventricular myocardial work technique, combined with the current indication criteria, to predict the long-term efficacy of patients with heart failure who are scheduled for CRT treatment, thereby increasing the response rate of CRT and improving the prognosis of patients. Currently, there are no normal reference values for left ventricular myocardial work in healthy Chinese adults. Therefore, our center has initiated this multicenter clinical research project, collaborating with multiple ultrasound centers across the country, aiming to establish the normal ultrasound values for left ventricular myocardial work in healthy Chinese adults, providing new quantitative reference basis for the diagnosis of myocardial function, assessment of the severity of myocardial lesions, and efficacy observation.