Compared with a sham procedure, pulmonary vein isolation resulted in a statistically significant and clinically important decrease in atrial fibrillation (AFib) burden at six months, according to results from the SHAM-PVI trial presented at ESC Congress 2024 in London and simultaneously published in JAMA. Researchers also noted substantial improvements in symptoms and quality of life.

SHAM-PVI involved 126 participants with symptomatic paroxysmal or persistent AFib who were randomly assigned to pulmonary vein isolation with cryoablation (n=64) or sham procedure with phrenic nerve pacing (n=62). The mean patient age was 66.8 years and 70.63% were men.

Results showed an average change in AFib burden from the start of the trial through six months of follow-up was 60% in the ablation group and 35% in the sham intervention group. Additionally, among patients with persistent AFib, researchers saw an average reduction in AFib burden of 71% in the ablation group and 45%in the sham intervention group. In those with intermittent AFib, an average reduction in AFib burden of 16% was observed, compared with an average increase of nearly 3% in the sham intervention group.

In other findings, overall quality of life scores substantially favored ablation and researchers said scores based on symptoms, daily activities, etc., were also better among those patients in the ablation group. Measures of health-related quality of life at six months, including physical and social functioning and emotional well-being were much improved in the ablation group vs. the sham group, researchers said.

"Despite being widely performed in clinical practice, pulmonary vein isolation ablation has never been compared with a sham procedure," said Principal Investigator Rick Veasey, MD. "Our results provide conclusive evidence for the benefit of pulmonary vein isolation ablation in individuals with symptomatic AFib, putting concerns about a substantial placebo effect to rest."