Tu1851

Increased Proximal Acid Reflux Is Associated With Early ReadmissionFollowing Lung TransplantationWai-Kit Lo, Robert Burakoff, Natan Feldman, Walter W. Chan

Background: Gastroesophageal reflux disease has been associated with poor long termoutcomes following lung transplantation. However, associations between pre-transplantreflux severity and early post-transplant outcomes, including time to readmission, have notbeen previously assessed. Aim: To evaluate the relationship between pre-transplant measuresof reflux severity and time to readmission following lung transplantation. Methods: Thiswas a retrospective cohort study of lung transplant recipients who underwent pre-transplantevaluation with multichannel intraluminal impedance and pH (MII-pH) study off acidsuppression medication at a tertiary care center since 2008. Subjects with pre-transplantNissen fundoplication were excluded. Time to readmission was defined as duration frompost-transplant discharge to the next hospital admission for any reason. Subgroup analysiswas performed to exclude re-admission dates for elective hospitalizations, including pulsesteroid initiation and observation after routine bronchoscopy. Time-to-event analysis usingCox proportional hazards model was applied to assess the relationship between MII-pHmeasures of reflux and time to readmission. Subjects not meeting this outcome were censoredat last pulmonary transplant clinic visit, or death, whichever was earliest. Fisher's exact testfor binary variables and student's t-test for continuous variables were performed to assessfor differences between readmission groups. Results: 33 subjects (58% men, mean age: 54,average follow-up: 1.7 years) met inclusion criteria for the study. Patient demographics andpre-transplant cardiopulmonary function were similar between rejection groups. Mean timeto readmission was 133 days. Time-to-event analysis revealed significant association betweentime to all-cause readmission and increased proximal acid episodes on impedance (HR 4.10,p=0.009), increased acid exposure time on pH monitoring (HR 1.09, p=0.03), and elevatedDemeester score (HR 1.03, p=0.02). When elective hospitalizations were excluded insubgroup analysis, early readmission remained significantly associated with proximal acidepisodes (HR 3.25, p=0.02), but not distal acid reflux parameters. Conclusion: Elevatedproximal acid reflux episodes on pre-transplant impedance assessment was associated withearly readmission following lung transplantation, even after excluding elective hospitaliza-tions for medication initiation or procedures. Exposure to acid reflux, even in the early post-operative phase, may have significant impact on the post-transplant clinical course. Aggressiveearly anti-reflux therapy should be considered in patients with significant reflux on pre-transplant testing. Impedance testing may have value as part of routine pre-transplantassessment given its association with early post-transplant outcomes.

Figure 1. Kaplan-Meier Analysis of time to readmission (all-cause) by proximal acid episodes.Increased proximal acid was associated with early readmission following transplantation.

S-855 AGA Abstracts

Figure 2. Kaplan-Meier Analysis of time to readmission (excluding elective hospitalization)by proximal acid episodes. Increased proximal acid was associated with early readmissionfollowing transplantation.

Tu1852

Jackhammer Esophagus Post-Lung Transplant: It's Not All Bad News for BolusClearanceCristina Almansa, Manuel Berzosa, Augustine Lee, Cesar A. Keller, Francisco G. Alvarez,David Erasmus, Jorge Mallea, Kenneth R. DeVault, Lesley A. Houghton

Ineffective esophageal motility (IEM) and gastroesophageal reflux are often seen in patientspost lung transplant (LTX) and are considered indirect risk factors for microaspiration andallograft failure. Thus, prophylactic fundoplication is sometimes considered post and evenpre-LTX. However, the relationship between motility and bolus clearance in these patientsremains unclear, and no study has explored this using the Chicago criteria. Aim: To assessesophageal motility in patients post-LTX using the Chicago criteria, and to investigate anyrelationship to swallowed bolus transit and reflux clearance. Methods: High resolutionesophageal manometry/impedance along with 24hr impedance/pH was performed on 30consecutive patients post LTX (aged 64yr(23-73),median(range);16 females); 70% of whomunderwent bilateral transplantation, mainly for pulmonary fibrosis (60%) and chronicobstructive pulmonary disease(28%). Median time from LTX to esophageal evaluation was3 months(2-4,IQR) and 74% were on PPIs at the time of study. Results: The most commonfinding was Jackhammer esophagus(12/30,40%), with the remaining showing IEM (2,7%),weak peristalsis with large/small breaks (WPL/SB;3,10%), absent peristalsis (AP;1,3%), distalesophageal spasm (2,7%), achalasia (2,7%), esophageal-gastric junction obstruction only(1,3%), and 7(23%) were classified as normal. Those who underwent single transplant weremore likely to exhibit normal motility (67%) than jackhammer (33%) or weak peristalsis(0%)(p=0.039). As expected those with hypo-contractility (IEM, WPL/SB, AP combined, n=6) tended to have a lower distal contractile integral (DCI)(p=0.073), a higher percentage ofswallows with incomplete bolus transit (IBT)(p=0.001) and a tendency for increased numberof reflux events compared with those with normal motility (Table). In contrast, those withJackhammer had increased both DCI (p<0.0001) and lower esophageal sphincter (LES)pressure (p<0.05), together with shorter reflux clearance times (RCT)(p=0.035) but similarpercentage of swallows with IBT and number of reflux events to those with normal motility.Thus compared with hypo-contractility, those with Jackhammer had significantly reducedpercentage of swallows with IBT (p<0.0001), increased LES pressure (p<0.07), reducednumber of proximal(p<0.05) and total (p<0.05) reflux events, and shorter RCT (p<0.07).Conclusion: These data show for the first time that Jackhammer is a significant finding post-LTX and that this is associated with both more effective swallowed bolus and reflux clearancetimes, together with reduced reflux episodes compared with hypo-contractility patterns. Thecause of Jackhammer and if there is any relationship with allograph failure still remains tobe elucidated but these data should be borne in mind when considering fundoplication.

Date expressed as median (IQR) except *mean (SD) . a1 p<0.10, a2<0.0001,a3p<0.07,a4<0.05 compared with normal; b1 p<0.001, b2 p<0.10, b3 p<0.05, b4 p<0.07compared with hypo-contractility

Tu1853

Idiopathic Pulmonary Fibrosis Is Associated With Increased ImpedanceMeasures of Reflux Compared to Non-Fibrotic Disease Among Pre-LungTransplant PatientsSravanya Gavini, Raymond T. Finn, Wai-Kit Lo, Hilary J. Goldberg, Robert Burakoff,Natan Feldman, Walter W. Chan

Background: Gastroesophageal reflux (GER) has been associated with idiopathic pulmonaryfibrosis (IPF). The underlying mechanism for this association remains unclear, as bothmicroaspiration of refluxate and increased transdiaphragmatic pressure gradient due tofibrosis have been implicated. Moreover, acid suppression therapy has shown mixed effecton pulmonary function in these patients suggesting that non-acidic GER may play a role.Our aim was to characterize the GER profile and its role in the pathogenesis of IPF bycomparing patients with IPF to those with non-fibrotic disease (NF) with similar pulmonaryfunction, using multichannel intraluminal impedance and pH study (MII-pH). Aim: Tocompare measures of GER on MII-pH between IPF and NF patients undergoing pre-lungtransplant evaluation. Methods: We performed a retrospective cohort study of IPF and NFpatients who underwent pre-lung transplant evaluation with MII-pH off acid suppressionmedications at a tertiary care center from 6/2010-9/2013. Patients with fundoplication priorto MII-pH were excluded. Patient demographics, medication use, co-morbidities includingBMI, MII-pH parameters, and pulmonary function test (PFT) results at the time of MII-pHwere recorded. Fisher's exact test for binary variables and student's t-test for continuousvariables were performed to assess differences between diagnosis groups. Results: 60 subjects(40 IPF vs. 20 NF, mean age: 59.6 yrs, 61.4% male) met criteria for inclusion. Patientdemographics, medication use, and pulmonary function were similar between diagnosisgroups. Compared to NF, IPF subjects had significantly increased mean episodes of proximalbolus reflux (27 vs. 16.9, p<0.05), proximal acid reflux (14.8 vs. 5.7, p=0.01), distal bolusreflux (64.6 vs. 40.4, p=0.02), distal bolus reflux in recumbent position (12.4 vs. 6, p=0.02), and distal nonacid reflux in recumbent position (6.8 vs. 2.5, p=0.01). When reflux

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