Novel scale for evaluating the therapeutic efficacy of per-oral endoscopic myotomy in achalasia.

Background: Symptom scales for achalasia after per-oral endoscopic myotomy (POEM) are lacking. This study aimed to propose a new scale based on the conventional Eckardt score (c-ES) and evaluate persistent symptoms that impair patients' quality of life (QOL) post-POEM.

Methods: Dysphagia, regurgitation, and chest pain frequencies were assessed using a 6-point scale modified-ES (m-ES) after POEM, with "occasional" symptoms on the c-ES further subdivided into three-period categories on m-ES. Symptom severity was further evaluated using a 5-point scale ranging from 1 to 5 points, with a score ≥ 3 points defined as persistent symptoms impairing QOL. We analyzed the correlation between the m-ES and severity score, diagnostic performance of the m-ES for persistent symptoms, and overlaps between each residual symptom.

Results: Overall, 536 patients (median follow-up period, 2.9 years) post-POEM were included in this multicenter study. Significant correlations were observed between the m-ES and severity scores for dysphagia (r = 0.67, p < 0.01), regurgitation (r = 0.73, p < 0.01), and chest pain (r = 0.85, p < 0.01). Twenty-six patients (4.9%) had persistent symptoms post-POEM, and 23 of them had m-ES-specific symptom frequency ≥ once a month, which was determined as the optimal frequency threshold for screening persistent symptoms. The total m-ES predicted persistent symptoms more accurately than the total c-ES (area under the curve: 0.95 vs. 0.79, p < 0.01). Furthermore, dysphagia and chest pain were the major residual symptoms post-POEM covering 91.4% of regurgitation.

Conclusions: The new post-POEM scale successfully evaluated the QOL-based patient symptom severities. Our study implied the possibility of a simpler scale using residual dysphagia and chest pain.