Early real-world outcomes of the 2023 refined dutch guidelines for non-ischemic cardiomyopathy mandating CRT-P treatment
L Broers, L Almeida Carrion, R Evertz, L R A Olde Nordkamp, V P van Halm, C P Allaart, L H G A HopmanAbstract
Background
The benefit of implantable cardioverter-defibrillator (ICD) back-up for primary prevention in patients with non-ischemic cardiomyopathy (NICM) undergoing cardiac resynchronization therapy (CRT) remains controversial. Declining rates of sudden cardiac death (SCD), attributed to contemporary guideline-directed medical therapy (GDMT) and CRT-induced reverse remodeling, have prompted reconsideration of routine ICD implantation in this population. In 2023, the Netherlands introduced a paradigm shift by recommending CRT with pacing (CRT-P), rather than CRT with defibrillation (CRT-D), in NICM patients with a left ventricular ejection fraction (LVEF) below 35%. Real-world implementation of this recommendation and its early clinical consequences are unknown.
Purpose
To evaluate real-world adherence of the 2023 Dutch guidelines recommending CRT-P over CRT-D in NICM patients undergoing de novo CRT implantation, and to assess ventricular arrhythmia and mortality outcomes.
Methods
A retrospective multicenter cohort study was conducted across two academic hospitals in the Netherlands. Consecutive adult patients with NICM, LVEF <35% despite ≥3 months of GDMT, and CRT implanted between April 2023 and January 2026 were included. Exclusion criteria included ischemic cardiomyopathy, secondary-prevention ICD indication, prior cardiac implantable device, infiltrative cardiomyopathy, or known high-risk genetic variants associated with SCD. Outcomes were guideline adherence, documented reasons for non-adherence, sustained ventricular arrhythmias, appropriate ICD therapy, and all-cause mortality (Figure 1).
Results
A total of 69 patients (57% male) were included. Mean age was 70 ± 9 years, and mean LVEF was 24 ± 7%. Pre-implantation cardiac magnetic resonance (CMR) imaging was performed in the majority of patients (87%), with late gadolinium enhancement (LGE) present in 26 patients (43%). CRT-P was implanted in accordance with the Dutch guideline in 49 patients (71%), whereas 20 patients (29%) received CRT-D. Most common reason for non-adherence was the presence of LGE on CMR (65%), followed by long estimated life expectancy (10%), adherence to ESC guidelines (10%), and undocumented deviation (15%). During a median follow-up of 10 months (range: 0-31 months), no sustained ventricular arrhythmias occurred. No appropriate ICD therapies were delivered. Two patients died, due to a non-cardiovascular and an undocumented cause respectively (Figure 2).
Conclusions
In this real-world multicenter cohort, adherence to the 2023 Dutch guideline was moderate. Presence of LGE on CMR influenced deviation toward CRT-D implantation, underscoring persistent uncertainty regarding arrhythmic risk stratification in NICM. No sustained ventricular arrhythmias were observed during early follow-up. Larger prospective studies with longer follow-up are warranted to refine patient selection, and identify NICM patients who may still benefit from defibrillator therapy.Figure 1Figure 2