The UNIFLECA study. prospective cohort study on flecainide impact on persistent high premature ventricular contraction burden and induced cardiomyopathy

Abstract Background/Introduction Persistent high Premature Ventricular Contraction (PVC) burden (>10%) may result in PVC-induced cardiomyopathy. Current guidelines, supported by limited evidence, recommend treatment with flecainide for PVCs originating in the ventricular outflow tract (Class IIa). Purpose UNIFLECA is a prospective cohort study aimed to assess the efficacy and safety of flecainide in PVC burden reduction in adults (irrespective of PVC origin), focusing secondarily on symptom relief and improvement in left ventricular ejection fraction (LVEF) in patients with PVC-induced cardiomyopathy. Methods Participants were adults with a PVC burden >5%, confirmed by two 24-hour Holter recordings taken at least one month apart, who denied catheter ablation treatment. Flecainide treatment was initiated with dosage adjustments based on follow-up Holter results and QRS increases. Changes in PVC burden, LVEF, symptoms, and treatment adherence were evaluated. Results As of September 2024, a cohort of 50 patients was screened. Persistent high PVC burden and eligibility criteria were met in 35 patients who initiated flecainide slow release treatment (Median time between Holter recordings: 162 days and 5 had previously undergone PVC ablation procedures). A daily dose of 100 mg slow-release flecainide was administered in 63.2% of patients, while the remaining patients were on a 200 mg daily regimen. Among them 19 were monitored over a one-month period following treatment initiation. A significant reduction was present in the mean PVC burden (mean decrease: 76.2% in the first month), with 63.1% of patients achieving a PVC reduction greater than 80%. Symptomatic improvement was observed in 74% of patients, with 25.8% reporting complete resolution of symptoms. Among those with baseline left ventricular ejection fraction (LVEF) impairment, functional improvement was noted, and 68% required dose adjustments to achieve optimal efficacy. No patients presented with QRS increase of >25% and no major adverse effects were observed. Conclusions Flecainide effectively reduces PVC burden and enhances symptomatic and functional outcomes in adults with persistent high PVC burden, irrespective of PVC origin, presenting a valuable alternative for patients ineligible or denying catheter ablation therapy.