Methods and Results: Data from 11,088 pts with a de novo implantation or upgrade from a previous device between 2015 and 2017 have been collected. Baseline QRSw was available in 7,481 pts. QRSw <120 ms at implant was present in 9.5%, 120-129 ms in 6.8%, 130-149 ms in 23.7% and of >150 ms in 60%. The table shows information on baseline characteristics and indication. In patients with a QRSw <130 ms CRT indication was most often HF with a primary indication for implantable cardioverter-defibrillator (ICD) or a pacemaker (pm) indication with expected high rate of right ventricular (RV) pacing. Implant success and complications did not differ between groups. At discharge, pts were more likely to receive loop diuretics, ACE inhibitors and aldosterone antagonists with increasing QRS width (p<0.00001 each).
Conclusion: More than 15% of pts in Europe receive a CRT device despite a baseline QRSw < 130 ms which is currently not a guideline-recommended CRT indication. In most of these pts CRT is implanted because of a primary ICD indication or presumed necessity of ventricular pacing in pts with a reduced LV function either because of AV conduction disturbances or atrial fibrillation (AF) requiring AV node ablation.