Associations between body surface gastric mapping parameters and response to gastric peroral endoscopic myotomy for gastroparesis.

BACKGROUND AND AIMS: Gastric per oral endoscopic myotomy (GPOEM) is a promising therapy for refractory gastroparesis, but patient selection remains challenging. We evaluated body surface gastric mapping (BSGM) phenotypes to predict treatment response. METHODS: Patients were recruited at King's College Hospital (Nov 2022-July 2025). BSGM comprised 30 min fasting, standardized nutrient drink with oatmeal bar (482 kcal), and 4 h postprandial recording. Success was defined as ≥1 point reduction in Gastroparesis Cardinal Symptom Index or complete symptom resolution at follow-up. RESULTS: Among 30 patients that completed follow-up (median 7.1 months, IQR 4.3-10.1; 77% female; median age 38.5, IQR 30-52), 53% responded to GPOEM, including all patients with dysrhythmic or continuous phenotypes. Higher gastric frequencies predicted non-response (adjusted odds ratio 0.01, 95% confidence interval 0.00-0.39, p=0.03). CONCLUSIONS: Clinical response to GPOEM varied by BSGM phenotype, offering a novel tool to aid patient selection.