Background and study aims. To evaluate the impact of power setting and proton pump inhibitor (PPI) dose on the efficacy and safety of argon plasma coagulation (APC) of Barrett's esophagus (BE) with low-grade dysplasia (LGD).

Patients and methods. Investigator initiated, single-center, parallel-group randomized controlled trial (RCT) conducted in a tertiary referral center in Poland. Consecutive patients with BE and LGD were randomly assigned to APC with power set at 90 Watt (90W) or 60 Watt (60W) followed by 120 mg or 40 mg omeprazole for six weeks. The primary outcome of the study was the rate of complete (endoscopic and histologic) ablation of BE at six weeks. Secondary outcomes included safety and long-term efficacy (at two years and at the end of a long-term follow-up of over 4 years.

Inclusion Criteria:

• consecutive adult patients with low-grade dysplasia in flat Barrett's mucosa referred for endoscopic treatment,
• signed an informed consent to participate in the study.

Exclusion Criteria:

• high-grade dysplasia or adenocarcinoma,
• visible lesions (nodules, ulcerations) in Barrett's mucosa,
• serious comorbidities and short life expectancy,
• coagulopathy,
• pregnancy or lactation,
• psychiatric disorders.

Patients were blinded to the power settings used for APC, but they knew the PPI dose they received. The endoscopist performing APC ablation was blinded to participant allocation and APC power setting (the power was set up by an assistant who knew the group allocation and the power display remained covered during the entire procedure). The endoscopist and pathologist involved in efficacy assessment were blinded to participant allocation.