A larger preimplant QRS area (HR, 0.89 p = <0.0001 adjusted HR, 0.93 p = 0.011) and a larger QRS area reduction (HR, 0.92 p = <0.0001 adjusted HR, 0.95 p = 0.042) postimplant correlated with a reduced risk of reaching the primary endpoint. Results: 147 patients (33%) reached the primary endpoint (93 deaths and 103 heart failure hospitalizations) over a median follow-up time of 2.7 years. Digital ECG before and after CRT implantation were collected, and ECG parameters were analyzed in relation to a primary composite endpoint of heart failure hospitalization or death from any cause. Methods: Medical records of 445 patients receiving CRT implants at a large-volume tertiary care center in Sweden were retrospectively evaluated. This study evaluates the incremental value of using QRS area derived from digital electrocardiogram (ECG) recordings, preoperatively and during CRT pacing. Previous studies have shown that QRS area reduction following CRT is associated with improved survival. However, current guideline indications do not accurately predict individual prognosis with CRT, and up to 30% are nonresponders. Introduction: Cardiac resynchronization therapy (CRT) is an established treatment for heart failure in selected patients.

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