Withdrawal of Heart Failure Treatment Patients With Non-ischemic Cardiomyopathy Who Have Been Super-responders to Cardiac Resynchronization Therapy.

Multicenter, prospective, non-inferiority, randomized, single-blind (primary endpoint evaluators blinded, patients not blinded) clinical trial. We aim to evaluate if the withdrawal of heart failure treatment is safe in patients with non-ischemic cardiomyopathy, negative genetic test, no evidence of late gadolinium enhancement on cardiac MRI, who have been super-responders to cardiac resynchronization therapy and remain free of heart failure events for at least 6 months after device implantation.

Inclusion Criteria: * Diagnosis of non-ischemic cardiomyopathy * LBBB already present at the time of first diagnosis of LV dysfunction * Negative genetic test * Cardiac MRI with no evidence of late gadolinium enhancement (LGE at RV insertion points is acceptable) * Carrier of a resynchronization device (ICD or pacemaker, with LV epicardial pacing form a cardiac vein or left bundle area pacing), pacing percentage \>95% and paced QRS \150 ms * LVEF ≥50% and normal indexed LV volumes on echocardiogram performed at least 6 months after CRT implantation * No heart failure decompensations (no hospitalizations or urgent/day hospital visits) since CRT implantation * No need for loop diuretic treatment * NYHA class I or II * NT-proBNP \