Prognostic value of late gadolinium enhancement cardiac MRI for ICD therapy in non-ischaemic cardiomyopathy: A 5-year cohort study

Aim: To evaluate the impact of the 2023 Dutch national guidelines for primary prevention implantable cardioverter-defibrillator (ICD) implantation on outcomes in non-ischaemic cardiomyopathy (NICM) patients and to assess the role of late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR) in predicting ICD therapy. Methods: This retrospective, single-centre observational exploratory cohort study included patients with NICM who received a primary prevention single-chamber, dual-chamber or subcutaneous ICD between January 2008 and April 2022 and underwent LGE-CMR prior to implantation. Patients were classified into LGE+ and LGE− groups based on the presence of late enhancement detected by CMR. The primary endpoint was time to first appropriate ICD therapy. The secondary endpoint was all-cause mortality. Results: Of the 258 NICM patients in the database, a total of 85 patients were included, of whom 41 had LGE on CMR. After a 5-year follow-up period, appropriate ICD therapy occurred in 20% of the patients in the LGE+ group and 14% of patients in the LGE− group (p = 0.37). All-cause mortality was 7% in the LGE+ group and 14% in the LGE− group (p = 0.46). Multivariable analysis showed no parameters significantly associated with appropriate ICD therapy. Conclusion: Applying the 2023 national guidelines retrospectively on a population of NICM patients with a primary prevention ICD indication demonstrated no significant association between LGE on CMR and appropriate ICD therapy over a follow-up period of 5 years. These findings underscore the need for further research and randomised trials to refine risk stratification and ICD implantation guidelines in NICM, ideally leveraging a multicentre approach to address current limitations in sample size and enhance the generalisability of the results.