QRS Index as a Predictor of Response to Cardiac Resynchronization Therapy: A Systematic Review and Meta-Analysis. - Corrado, Egle; Stabile, Francesco; Jaramillo, Sebastian; Niño Lopez, Mariana; Mirabella, Marco; Madaudo, Cristina; Sucato, Vincenzo; Galassi, Alfredo Ruggero; De Ponti, Roberto; Coppola, Giuseppe (Journal of Clinical Medicine, 2026)