Impact of catheter ablation on ventricular arrhythmias in left ventricular assist device patients: findings from the MUST-LVAD-VT international registry

Background Ventricular arrhythmias (VAs) have been reported as factors that worsen the prognosis of patients undergoing left ventricular assist device (LVAD) implantation. Previous studies have identified a history of VAs before implantation as a risk factor for electrical storms and poor outcomes. However, the impact of perioperative catheter ablation on early recurrence of VAs and clinical outcomes after LVAD implantation remains controversial. In addition, no comprehensive report has examined cases managed without ablation therapy, and the optimal strategy for managing VAs in LVAD patients has yet to be established. Purpose To investigate the clinical outcomes of patients with VAs who underwent LVAD implantation. Methods This was an international, multicentre, observational cohort study conducted at 23 institutions in Japan and Korea. Patients who experienced VAs and underwent LVAD implantation between January 2018 and December 2022 were retrospectively enrolled. Those with VAs prior to LVAD implantation were divided into two groups: patients who underwent catheter ablation before implantation (Group A) and those who did not (Group B). Patients without pre-implantation VAs who developed VAs only after LVAD implantation were classified as Group C. Patient characteristics and clinical outcomes were compared according to the presence or absence of early-phase VAs and pre-implantation ablation, and the effect of post-implantation ablation was also assessed. Results A total of 174 patients were included (Group A, n=47; Group B, n=108; Group C, n=19). The mean age was 51 years (interquartile range [IQR]: 40-59), and 74% were male. The underlying aetiology was ischaemic cardiomyopathy (11%), non-ischaemic cardiomyopathy (81%), and mixed (7%). The mean follow-up duration was 1171 (IQR: 954-1486) days. There was no significant difference in survival among the three groups. In Cox regression analysis, early-phase VAs (<3 months post-implantation) and modifier A were independent predictors of survival (hazard ratio [HR]:2.19, 95% confidence interval [CI] 1.34-3.58, p=0.002; HR 2.82, 95%CI 1.73-4.60, p<0.001, respectively). In Group A, comprising patients who underwent catheter ablation prior to LVAD implantation, early-phase VAs did not adversely affect survival, as rates were comparable between those with and without early-phase VAs (88% vs. 87%). In contrast, in Group B, comprising patients without pre-implantation ablation, survival was significantly lower in those with early-phase VAs compared with those without (64% vs. 87%, p=0.0083). Conclusions Early-phase VAs are a risk factor for all-cause mortality in patients undergoing LVAD implantation, as previously reported. However, pre-implantation catheter ablation may mitigate this risk, potentially improving survival in patients with a history of VAs prior to LVAD implantation.