S124 Abstracts of the XVII National Congress of Digestive Diseases / Digestive and Liver Disease 43S (2011) S115–S264 since they cause underestimation of GERD patients and overestimation of FH patients. Impedance-pH monitoring is more accurate in identifying GERD or FH and should be included in the future iteration of Rome criteria. OC.03.4 PATIENTS WITH EXTRA-ESOPHAGEAL SYMPTOMS, COMPARED TO NERD PATIENTS WITH TYPICAL SYMPTOMS AND HEALTHY VOLUNTEERS, ARE CHARACTERIZED BY A HIGHER NUMBER OF REFLUX EPISODES AND HIGHER PROPORTION OF WEAKLY ACIDIC AND MIXED REFLUX M. Ribolsi ∗ ,1 , P. Balestrieri 1 , M.C. Addarii 1 , S. Emerenziani 1 , F. Greco 1 , M. Casale 1 , F. Salvinelli 1 , F. Pace 2 , M. Cicala 1 1 Università Campus Bio Medico, Roma, Italy; 2 Ospedale Bolognini, Bergamo, Italy Background and aim: Although extra-esophageal symptoms are present in >30% of GERD patients, the role of gastric refluxate still remains unclear. In patients with extra-esophageal symptoms, pH monitoring is often in the normal range and the response to PPI therapy is poor. Few data are currently available concerning the properties of reflux in these patients when compared to those in patients with typical or combined typical and atypical symp- toms, as well as concerning the predictive value of esophageal multichannel impedance-pH (MI-pH) monitoring for the PPI response. Material and methods: 61 NERD patients presenting with extra-esophageal symptoms underwent, following a 3-week pharmacological washout, MI-pH following stationary manometry (EE group). Patients filled out a question- naire with symptom score. 32 of the 61 EE presented only extra-esophageal symptoms (EE only), the remaining 29 patients also presented typical GERD symptoms (EE+T). 36 of the 61 EE had not shown a satisfactory response to 8 weeks double dose PPI therapy (<50% improvement). MI-pH findings were compared to those obtained in 54 NERD patients with typical symptoms responding to PPI and to normal values reported in an Italian population of healthy volunteers (HV). Results: 19/61 EE (31%) and 24/54 NERD (44%) patients presented patho- logical acid exposure time (AET). AET was positive in 10/33 patients of the EE only group and in 9/30 patients of EE+T group. AET was positive in 13/36 Abstract OC.03.5 – Table 1. Reflux parameters in subgroups of NERD patients and HV patients pH-POS/SAP+ pH-POS/SAP- pH-NEG/SAP+ pH-NEG/SAP- HV p-value (ANOVA) % pH <4 total 6.2 (4.6-9) b,c,d 4.5 (4.4-6.3) e,f,g 1.7 (0.7-2.7) b,e,h,i 0.8 (0.3-1.8) c,f,h 0.7 (0.1-1.4) d,g,i <0.01 MACT total 136 (88-181) a,b,c,d 85 (78-269) a,e,f,g 43 (27-67) b,e 41 (22-70) c,f 32 (16-50) d,g <0.01 MBCT total 16 (13-22) b,c,d 15 (13-21) e,f,g 13 (10-18) b,e, 12 (10-19) c,f 12 (8-16) d,g <0.01 Prox. extent (%) 52 (39-62) a,c,d 33 (22-55) a,e 57 (42-69) e,h,i 33 (23-49) c,h 33 (18-46) d,i <0.01 Data are presented as median (25th-75th percentile). Post-hoc analysis. a pH-POS/SAP+ vs. pH-POS/SAP-, p<0.05; b pH-POS/SAP+ vs. pH-NEG/SAP+, p<0.05; c pH-POS/SAP+ vs. pH-NEG/SAP-, p<0.05; d pH-POS/SAP+ vs. HV, p<0.05; e pH-POS/SAP- vs. pH-NEG/SAP+, p<0.05; f pH-POS/SAP- vs. pH-NEG/SAP-, p<0.05; g pH-POS/SAP- vs. HV, p<0.05; h pH-NEG/SAP+ vs. pH-NEG/SAP-, p<0.05; i pH-NEG/SAP+ vs. HV, p<0.05. PPI non responder and 6/25 responder patients. Findings of MI-pH are shown in the table. The total reflux number and the proportions of weakly acidic, mixed and proximal reflux did not differ between EE patients (PPI responders and non-responders). Number of refluxes Weakly acidic Mixed reflux Proximal (%) (%) (%) EE 62 (39-113)* 51% (34-64%)* 71% (43-84%)* 68% (59-80%) EE only/ 56 (37-105)/ 51% (35-68%)/ 70% (43-84%)/ 68% (61-78%)/ EE+T 66 (46-134) 50% (31-63%) 75% (54-84%) 67% (53-82%) NERD 28 (20-41) 32% (16-42%) 54% (45-70%) 64% (30-78%) HV 16 (9-27) 43% 58% 62% *p< 0.05. Data are expressed as median and 25th–75th percentile values. Conclusions: Patients with extra-esophageal symptoms, compared to NERD patients with typical symptoms and HV, are characterized by a higher number of reflux episodes and higher proportion of weakly acidic and mixed refluxes. Although this reflux pattern could explain the reduced response to PPI treat- ment, MI-pH findings do not seem to predict the PPI response in this group of patients. OC.03.5 REFLUX PATTERNS DIFFER AMONG PATIENTS WITH NON-EROSIVE REFLUX DISEASE (NERD), HYPERSENSITIVE ESOPHAGUS (HE) AND FUNCTIONAL HEARTBURN (FH) E. Savarino ∗ , P. Zentilin, E. Marabotto, M. Furnari, G. Sammito, L. Gemignani, A. Malesci, C. Mansi, V. Savarino Division of Gastroenterology, Department of Internal Medicine, University of Genoa, Genoa, Italy Background and aim: Non-erosive reflux disease (NERD) is an heteroge- neous condition including patients with different pathophysiological character- istics. There are limited data on reflux patterns in them. To compare reflux pat- terns in NERD patients subclassified by impedance-pH monitoring (MII-pH). Material and methods: Patients with typical reflux symptoms and normal endoscopy underwent MII-pH off-PPI therapy. PPI therapy was discontinued >30 days prior to testing. Forty-eight healthy volunteers (27F; mean age 42yrs; HV) served as controls. Esophageal acid exposure time (AET), charac- teristics of reflux episodes (acid/nonacid), mean acid clearance time (MACT), median bolus clearance time (MBCT), proximal migration of refluxate and symptom association probability (SAP) were measured. Results: Of 251 NERD patients (118M; mean age 47yrs), 92 (37%) were pH-POS/SAP+, 10 (4%) pH-POS/SAP-, 86 (34%) were pH-NEG/SAP+ (Hypersensitive Esophagus) and 63 (25%) were pH-NEG/SAP- (Functional Heartburn). The total and acid reflux episodes were significantly higher (p<0.01) in pH-POS/SAP+ (median 60 [25th-75th perc. 45-94] and 44 [33-59]) and pH-POS/SAP- (58 [54-87] and 44 [42-65]) compared to pH- NEG/SAP+ (43 [26-64] and 25 [11-37]), pH-NEG/SAP- (30 [17-43] and 16 [8-27]) and HV (32 [19-43] and 17 [8-31]). Patients pH-NEG/SAP+ had a significantly increased number of weakly acidic reflux episodes compared to pH-POS/SAP+, pH-POS/SAP-, pH-NEG/SAP- and HV (27 [15-41] vs. 19 [13-26] vs. 20 [13-57] vs. 22 [15-28] vs. 18 [14-26]; p<0.01). Differences in AET, acid and bolus clearance times and percentage of proximal reflux episode are shown in Table 1. Conclusions: Patients with abnormal AET have the most severe degree of reflux disease. In patients with normal AET and SAP+, an increased num- ber of weakly acidic reflux and a high rate of proximal reflux are the main