Primary prevention ICD in non-ischaemic cardiomyopathy: an ongoing search for improvement of current indications : A retrospective study analysing the impact of the new Dutch guideline on the use of ICDs.

Introduction: Patients with non-ischaemic cardiomyopathy (NICMP) have a class IIa primary prevention indication for an implantable cardioverter-defibrillator (ICD). Recent studies have shown that the evidence for a survival benefit following ICD implantation in this patient group is not particularly robust. In 2023, the Dutch Society of Cardiology published an update of the ESC guideline to better select patients with NICMP for ICD implantation. The objective of this study was to analyse the impact of this guideline on the number of indications in a retrospective cohort of patients who had received an ICD and whether the patients without an indication were also without appropriate ICD therapy.

Methods: A single-centre, retrospective observational study was performed in 134 patients with NICMP who underwent ICD implantation for primary prevention between 2015 and 2020.

Results: After applying the new Dutch guideline, 74 out of 134 patients with NICMP without a high-risk phenotype (35 patients) had no ICD indication (group 2). The remaining 25 patients were considered to have an ICD indication (group 1). During a median follow-up of 66 months (interquartile range 52-81) the incidence of appropriate ICD therapy (antitachycardia pacing and shock) was comparable in both groups: 4 patients in group 1 (16%) and 9 in group 2 (12%), p = 0.623.

Conclusion: The new 2023 guideline for ICD implantation in NICMP patients does indeed rule out a significant group of patients from ICD implantation. Nevertheless, our data show that patients without an indication still had comparable rates of appropriate ICD therapy.