Dr. Burak Kardeşler

Title:
Pulmonary Vein Isolation Versus Sham Intervention in Symptomatic Atrial Fibrillation - SHAM-PVI

Congress:
ESC 2024

LINK:
SHAM-PVI Study on JAMA Network

Introduction:
The SHAM-PVI study has demonstrated that cryoballoon PVI in symptomatic paroxysmal or persistent AF patients is associated with reduced AF burden and symptomatic improvement compared to a sham procedure.

Objective:
The aim of the study is to compare the clinical efficacy of cryoballoon PVI versus a sham procedure in symptomatic AF patients.

Method:
The study is a double-blind, randomized design. Participants were randomly assigned in a 1:1 ratio to receive either cryoballoon (n=64) or sham phrenic nerve stimulation (n=62) via the same femoral access. AF burden was assessed using an implantable loop recorder (ILR) that recorded AF episodes lasting longer than 2 minutes. The average follow-up period was 6 months.

Participants included those over 18 years old with symptomatic paroxysmal or persistent AF despite beta-blockers or class 1 and 3 antiarrhythmic drugs. Major exclusion criteria included a history of previous AF ablation, long-standing persistent AF, LA diameter >5.5 cm, LVEF <35%, and other arrhythmias requiring ablation.

Results:
In the SHAM-PVI study, 79% of patients had persistent AF, with an average CHA2DS2-VASc score of 2. The average time since AF diagnosis was 24.5 months, and the average LVEF was 55%.

In the primary endpoint of the SHAM-PVI study, the AF burden in the cryoballoon PVI group was 18.2% at 6 months, compared to 43.2% in the sham phrenic nerve stimulation group, showing a significant difference between the two groups (p<0.001).

Regarding secondary endpoints at 6 months, the AF Effect on Quality of Life (AFEQT) score, Mayo AF-Specific Symptom Inventory (MAFSI) score, and 36-Item Short Form Health Survey (SF-36) score were significantly higher in support of PVI.

Conclusion:
The SHAM-PVI study showed that PVI is associated with a reduction in AF burden and symptomatic improvement, either alone or compared to medical therapy. This study is the first to compare cryoballoon PVI with a sham procedure. The observed improvement in symptoms and quality of life at 6 months with PVI was compared to a placebo. The reduction in AF burden was objectively demonstrated with ILR. However, these findings may not be applicable to patients with long-standing persistent or paroxysmal AF, or those with advanced left atrial dilation.

Comment:
The SHAM-PVI study indicates that cryoballoon PVI, when selected for the right patient population, leads to improvements in symptoms and quality of life in patients with paroxysmal and persistent AF.