In this sub-study of the MADIT-CRT population, we investigate the predictive value of electrocardiographic scar burden estimation by Selvester QRS scoring.

Scar burden by QRS scoring predicts clinical prognosis in ICD and CRT receipients, but not CRT efficacy in preventing heart failure events or death, in the LBBB subgroup (no interaction between higher QRS score and CRT assignment).

Higher QRS score is associated with less LV remodeling and less recovery of LVEF by echocardiography at 6-month follow-up after CRT.