A randomized sham-controlled study of pulmonary vein isolation in symptomatic atrial fibrillation (The SHAM-PVI study): Study design and rationale.

Introduction: Pulmonary vein (PV) isolation has been shown to reduce atrial fibrillation (AF) burden and symptoms in patients. However, to date previous studies have been unblinded raising the possibility of a placebo effect to account for differences in outcomes.

Hypothesis & Methods: The objective of this study is to compare PV isolation to a sham procedure in patients with symptomatic AF. The SHAM-PVI study is a double blind randomized controlled clinical trial. 140 patients with symptomatic paroxysmal or persistent AF will be randomized to either PV isolation (with cryoballoon ablation) or a sham procedure (with phrenic nerve pacing). All patients will receive an implantable loop recorder. The primary outcome is total AF burden at 6 months postrandomisation (excluding the 3 month blanking period). Key secondary outcomes include (1) time to symptomatic and asymptomatic atrial tachyarrhythmia (2) total atrial tachyarrhythmia episodes and (3) patient reported outcome measures.

Results: Enrollment was initiated in January 2020. Through April 2023 119 patients have been recruited. Results are expected to be disseminated in 2024.

Conclusion: This study compares PV isolation using cryoablation to a sham procedure. The study will estimate the effect of PV isolation on AF burden.