Lower-than-Standard Cutoff Number of Reflux Episodes is Associated with Worse Lung Transplant Outcomes

Abstract

Listen

Translate article

<h3>Purpose</h3> Gastroesophageal reflux disease (GERD) is a common condition in patients with end-stage lung disease. Previous cohorts have shown an association between GERD and chronic lung allograft dysfunction (CLAD), but these findings have not been consistent. Our previous studies show that GERD, defined as >48 total reflux episodes is not associated with CLAD. We hypothesized that the cutoff to define GERD in lung transplant recipients (LTRs) may be different from that of the general population and that lesser numbers of reflux episodes might be associated with CLAD or death/retransplant. <h3>Methods</h3> We retrospectively analyzed 750 LTRs between 2000-2018, who had 24h pH/impedance testing available within seven months post-transplantation. Univariable Cox proportional hazards models were used to assess the association between total and proximal reflux episodes with CLAD or death/retransplant. Using the highest tertile, we stratified patients as having significant reflux using a cutoff of 24 for total reflux episodes and 11 for proximal reflux. <h3>Results</h3> In our cohort, the median number of total reflux episodes and proximal reflux episodes/24h was 16 (IQR = 8-28) and 5 (IQR = 1-14), respectively. Total reflux episodes, when modeled as a continuous variable, were associated with CLAD [HR 1.005 (1.002-1.007); p<0.01] and death [HR 1.004 (1.001-1.007); p<0.01]. LTRs with >24 reflux episodes had a higher risk of CLAD [HR 1.53 (1.22-1.92); p<0.001], but not death/retransplant [HR 1.20 (0.97-1.50); p=0.09]. LTRs with >11 proximal reflux episodes were not at risk for CLAD [HR 1.26 (0.99-1.59); p=0.06] or death [HR 1.09 (0.87-1.38); p=0.44] <h3>Conclusion</h3> In a large single-center cohort, we observed that total reflux episodes are associated with an increased risk of CLAD and death/retransplant, with a cutoff of 24 reflux episodes portending an increased risk for CLAD. Our data suggests that LTRs with a number of reflux episodes that to do not meet the standard definition of GERD might still be at risk for adverse outcomes.