The Chicago Classification version 4 (CCv4) introduced stricter criteria for diagnosing Ineffective Esophageal Motility (IEM), raising the threshold to >70% ineffective swallows or ≥50% failed peristalsis. This study aimed to evaluate the demographic, clinical, endoscopic, and manometric differences between patients who retained the diagnosis of IEM under CCv4 criteria and those who were declassified from the previous CCv3 definition

We conducted a retrospective study of patients undergoing High-Resolution Manometry (HRM) at a tertiary care center in Western India between September 2020 and April 2024. Patients meeting CCv3 criteria for IEM were included and re-evaluated using CCv4 criteria. The cohort was divided into two groups: Group 1 (Retained IEM as per CCv4) and Group 2 (Declassified). We compared demographics, clinical symptoms, upper GI endoscopy findings, and HRM metrics—specifically analyzing failed versus weak swallows and peristaltic reserve—between the two groups.

Out of 101 patients meeting CCv3 IEM criteria, 80 (79%) retained the diagnosis under CCv4 (Group 1), while 21 (21%) were declassified (Group 2). There were no statistically significant differences between the groups regarding age, gender, comorbidities, clinical symptoms (dysphagia, regurgitation, chest pain), or endoscopic findings (hiatal hernia, erosive esophagitis).However, manometric profiles differed significantly. Group 1 had a significantly lower mean Distal Contractile Integral (DCI) compared to Group 2 (234.6 vs. 422.7 mmHg·s·cm; p<0.001). Notably, 64% of Group 1 patients exhibited failed swallows, whereas Group 2 had zero failed swallows, presenting exclusively with weak swallows (p<0.0001). Esophageal contraction reserve on multiple rapid swallows (MRS) was not significantly different between the groups (p=0.114).

Application of CCv4 criteria declassified 21% of patients previously diagnosed with IEM. While the new criteria did not correlate with distinct clinical or endoscopic presentations, they successfully identified a manometrically severe subgroup characterized by lower DCI and the presence of failed contractions. Since failed swallows are associated with poorer bolus clearance, CCv4 appears to select for patients with more profound peristaltic dysfunction who may require distinct management strategies.