Association of Premature Ventricular Contraction Burden on Serial Holter Monitoring with Arrhythmic Risk in Patients with Arrhythmogenic Right Ventricular Cardiomyopathy

Importance: A high burden of premature ventricular contractions (PVCs) at disease diagnosis has been associated with an overall higher risk of ventricular arrhythmias in arrhythmogenic right ventricular cardiomyopathy (ARVC). Data regarding dynamic modification of PVC burden at follow-up with Holter monitoring and its impact on arrhythmic risk in ARVC are scarce. Objective: To describe changes in the PVC burden and to assess whether serial Holter monitoring is dynamically associated with sustained ventricular arrhythmias during follow-up in patients with ARVC. Design, Settings, and Participants: In this cohort study, patients with a definite ARVC diagnosis, available Holter monitoring results at disease diagnosis, and at least 2 additional results of Holter monitoring during follow-up were enrolled from 6 ARVC registries in North America and Europe. Data were collected from June 1 to September 15, 2021. Main Outcomes and Measures: The association between prespecified variables retrieved at each Holter monitoring follow-up (ie, overall PVC burden; presence of sudden PVC spikes, defined as absolute increase in PVC burden ≥5000 per 24 hours or a relative ≥75% increase, with an absolute increase of ≥1000 PVCs; presence of nonsustained ventricular tachycardia [NSVT]; and use of β-blockers and class III antiarrhythmic drugs) and sustained ventricular arrhythmias occurring within 12 months after that Holter examination was assessed using a mixed logistical model. Results: In 169 enrolled patients with ARVC (mean [SD] age, 36.3 [15.0] years; 95 men [56.2%]), a total of 723 Holter examinations (median, 4 [IQR, 4-5] per patient) were performed during a median follow-up of 54 (IQR, 42-63) months and detected 75 PVC spikes and 67 sustained ventricular arrhythmias. The PVC burden decreased significantly from the first to the second Holter examination (mean, 2906 [95% CI, 1581-4231] PVCs per 24 hours; P <.001). A model including 24-hour PVC burden (odds ratio [OR] 1.50 [95% CI, 1.10-2.03]; P =.01), PVC spikes (OR, 6.20 [95 CI, 2.74-13.99]; P <.001), and NSVT (OR, 2.29 [95% CI, 1.10-4.51]; P =.03) at each follow-up Holter examination was associated with sustained ventricular arrhythmia occurrence in the following 12 months. Conclusions and Relevance: These findings suggest that in patients with ARVC, changes in parameters derived from each Holter examination performed during follow-up are associated with the risk of sustained ventricular arrhythmias within 12 months of disease diagnosis.