Long-term outcomes after subcutaneous implantable cardioverter-defibrillator implantation in patients with genetic cardiac arrhythmias
Y Matsuda, K Kooiman, A De Weger, L Smeding, L R A Olde Nordkamp, R E KnopsAbstract
Background
The subcutaneous implantable cardioverter-defibrillator (S-ICD) is a well-established therapy for preventing sudden cardiac death and is an alternative to transvenous implantable cardioverter-defibrillator (TV-ICD). S-ICD has a lower risk of major and lead-related complications than TV-ICD; therefore, it could be a good option for patients with genetic cardiac arrhythmias, who tend to be younger than those without. However, there are few reports on the long-term follow-up of patients with genetic cardiac arrhythmias after S-ICD implantation.
Purpose
The purpose of this study was to investigate the long-term outcomes after index S-ICD implantation for genetic cardiac arrhythmias.
Methods
Between February 2009 and September 2024, 201 consecutive patients (dipeptidyl-peptidase 6 [DPP6] mutation 52, long QT syndrome 6, Brugada syndrome 18, hypertrophic cardiomyopathy [HCM] 78, arrhythmogenic cardiomyopathy [ACM] 34, others 13) who underwent index S-ICD implantation for genetic cardiac arrhythmias in our hospital were retrospectively enrolled. The main study endpoints were device-related complications, ventricular tachyarrhythmia which was defined as a composite of appropriate therapy and ventricular tachycardia without therapy, and inappropriate therapy after index S-ICD implantation.
Results
Mean age of the study population was 40 ± 15 years. During the follow-up period of 7.7 (3.8–12.0) years, 7 (3.5%) patients died. Device-related complications occurred in 42 (20.9%) patients, and freedom from device-related complications was similar for each genetic disease type (Figure 1). Ventricular tachyarrhythmia were observed in 38 (18.9%) patients, and there was a significant difference in freedom from ventricular tachyarrhythmia among each genetic disease type (p<0.01) (Figure 2A). Inappropriate therapy occurred in 35 (17.4%) patients. There was no significant difference in the number of patients with inappropriate therapy before and after 2018 (12 [6.0%] vs. 24 [11.9%]), and 9 (25.7% of inappropriate therapy) patients experienced recurrent inappropriate therapy. There was a significant difference in freedom from inappropriate therapy among each genetic disease type (p<0.01) (Figure 2B). In a multivariate analysis, DPP6 mutation was an independent negative predictor (hazard ratio [HR]: 0.242; 95% confidence interval [CI]: 0.084–0.702; p<0.01), and HCM (HR: 2.07; 95% CI: 1.06–4.02; p=0.033) and ACM (HR: 2.24; 95% CI: 1.11–4.54; p=0.024) were independent positive predictors of ventricular tachyarrhythmia. Regarding inappropriate therapy, QRS duration at index S-ICD implantation was an independent positive predictor (HR: 1.37 per 10 msec; 95% CI: 1.16–1.62; p<0.01).
Conclusion
In the long-term follow-up after index S-ICD implantation, the rates of freedom from ventricular tachyarrhythmia and inappropriate therapy differed significantly among each genetic disease type, however freedom from device-related complication was similar.Device-related complicationsClinical events