Prospective Assessment of Premature Ventricular Contractions Suppression in Cardiomyopathy(PAPS): A Pilot Study

Rationale. Frequent PVCs have shown to induce a reversible cardiomyopathy (PVC-CM). Yet, it is unclear why some patients develop PVC-CM, while others do not. Appropriate diagnosis and treatment of patients with PVC-CM is believed to carry significant benefits, improving quality of life (QOL), HF symptoms / admissions and life expectancy. Currently, these patients are offered radiofrequency ablation (RFA), antiarrhythmic drugs (AADs) or no treatment depending on physician's experience and resources. Nevertheless, no randomized-prospective study exists to support the benefit of RFA. Thus, a large-scale multicenter randomized clinical trial entitled "Prospective Assessment of PVC Suppression in Cardiomyopathy (PAPS)"' study has been planned to compare these treatment strategies. However, a PAPS pilot study is proposed to better estimate the potential affected patient population, limitations of enrollment, rate of clinical outcomes, potential crossover and drop out. This pilot study is key to better design and power the large-scale multicenter PAPS trial.

Objective. PAPS pilot study is a randomized clinical trial to assess the feasibility of enrolling, randomizing treatment strategies and retaining participants with frequent PVCs and associated CM.

Hypotheses. Our main hypotheses of the PAPS pilot study are:

1. A large-scale randomized PAPS clinical study is feasible with minimal barriers of enrollment, treatment crossover and drop out due to a unique design including a short observation period and PVC suppression strategy in all participants.
2. The rate of responders (defined as improvement of LVEF ≥ 10% points) with HF medical therapy alone during observation period will be less than 15%. In contrast, RFA and AADs will have a responder rate of at least 35% in the same population. Furthermore, RFA will have a greater 1-year response rate when compared to AAD therapy.
3. RFA will have a lower rate of composite adverse events (worsening NYHA class, HF admission, treatment side effects & complications, and death), arrhythmia burden and a better long-term tolerance than AADs.

Methods. A prospective clinical pilot study is planned to prove the feasibility of a large-scale multicenter clinical trial (PAPS study) of patients with probable PVC-CM. This pilot study will enroll 36 patients with frequent PVCs (burden ≥10%) and CM (LVEF ≤45%) and randomize them to either: 1) RFA or 2) AADs. Prior to treatment, all patients will undergo a baseline cardiac MR if clinically indicated and be allowed a 3-month observation period (optimal HF medical therapy). To assess the effects of PVC suppression, changes in LV function, rate of responders (defined above), PVC burden/arrhythmias and clinical/functional status (QOL, HF symptoms and admissions, NYHA class) and adverse events will be compared between observation period and both PVC suppression strategies (RFA or AAD). To identify the best PVC suppression strategy, similar comparisons between RFA and AAD treatment groups will be performed at 12-month follow up using a Prospective Randomized Open, Blinded End-point (PROBE) study design. The treatment regimens will be compared in an intention-to-treat analysis.