505 SURPRISING LACK OF CORRELATION BETWEEN INTEGRATED RELAXATION PRESSURE LEVEL AND SYMPTOM SEVERITY IN PATIENTS WITH ACHALASIA

Abstract

Abstract With high resolution manometry (HRM), achalasia is defined as an elevated integrated relaxation pressure (IRP) and the absence of normal esophageal peristalsis. Since achalasia symptoms are attributed in part to incomplete LES relaxation, IRP values might be expected to directly correlate with symptom severity. The aim of this study was to evaluate the relationship between IRP values and symptom severity assessed by the Eckardt score in patients with achalasia. Methods We searched the database of our Center for Esophageal Diseases for patients who had HRM showing achalasia (IRP > 15 mmHg and absent peristalsis) between May 2017 and August 2019. All patients with achalasia seen in our Center routinely complete the Eckardt score questionnaire evaluating the severity of achalasia symptoms in each of four categories (dysphagia, chest pain, regurgitation and weight loss). Pearson correlation coefficient was used to assess the relationship between median IRP and Eckardt score; an R2 value >0.5 was considered clinically meaningful. Results We identified 91 subjects with achalasia (mean age 62.9 ± 16.5 years; 39 men, 52 women; 27 Type 1, 28 Type 2, 36 Type 3). We found no clinically meaningful correlation between median IRP and the total Eckardt score (R2 = 0.043) (Figure 1). Furthermore, we found no clinically meaningful correlation between median IRP and any individual component of the Eckardt score (dysphagia R2 = 0.008, chest pain R2 = 0.001, regurgitation R2 = 0.035, weight loss R2 = 0.049). Finally, in subgroup analyses we found no clinically meaningful correlation between median IRP and Eckardt scores (total or any of its individual components) for any of the 3 achalasia subtypes. Conclusion We found no clinically meaningful correlation between IRP and total Eckardt score, or between IRP and any individual component of the Eckardt score for patients with achalasia of any type. This suggests that once the IRP value exceeds 15 mmHg, further elevations in IRP have little effect on symptoms, and that factors other than IRP such as esophageal body dysmotility and hypersensitivity might contribute to symptom perception in achalasia.