Arrhythmic genotypes in dilated cardiomyopathy and risk of advanced heart failure

Abstract

BACKGROUND AND AIMS: Certain genetic forms of dilated cardiomyopathy (DCM) entail a higher arrhythmic risk. It is unknown whether DCM patients with high-risk arrhythmic genotypes also develop more advanced heart failure (AHF) complications. AHF events were studied according to DCM genotype. METHODS: Clinical data from 1203 genotyped DCM patients were collected from 19 Spanish centres. Patients were classified into high-risk arrhythmic genotypes (LMNA, FLNC, desmosomal genes, PLN, TMEM43, RBM20), TTN, other genes, and genotype negative (Gen-). The primary endpoint was a composite of AHF events (ventricular assist device implantation, heart transplant, and AHF-related mortality). The secondary endpoint was a combination of malignant ventricular arrhythmias (MVA). RESULTS: A DCM-causing variant was identified in a high-risk arrhythmic gene in 185 patients (15.4%), 193 (16.0%) had variants in TTN, 134 (11.1%) in other genes, and 691 (57.4%) were Gen-. After a median follow-up of 5.7 years (interquartile range 2.9-9.1 years), AHF events occurred in 45 (24.3%) patients in the high-risk arrhythmic group, while in 25 (18.7%), 25 (13.0%), and 70 (10.1%) patients with other genotypes, TTN, and Gen-, respectively (hazard ratio 1.85, 95% confidence interval 1.31-2.61 for high-risk arrhythmic genes compared with other groups). MVA occurred in 55 patients (29.7%) (hazard ratio 2.52, 95% confidence interval 1.81-3.51 for high-risk genotypes vs other groups). High-risk arrhythmic genotype was the main independent predictor of AHF in multivariate analysis. High-risk arrhythmic genotype and late gadolinium enhancement were independent predictors of MVA. CONCLUSIONS: Patients with high-risk arrhythmic genotypes also experience more AHF events, supporting a differential therapeutic approach in this group of patients beyond sudden death prevention.