Usefulness of pH monitoring in predicting the survival status of patients with scleroderma awaiting lung transplantation.

BACKGROUND: Patients with scleroderma and end-stage lung disease (ESLD) have a very high prevalence of gastroesophageal reflux disease (GERD). Because GERD has been associated with aspiration in those with ESLD, and because those with scleroderma are particularly prone to develop severe GERD, there is some concern that GERD may contribute to shorten survival in patients with scleroderma awaiting lung transplantation. Therefore, we hypothesized that esophageal pH monitoring could predict survival of those with scleroderma and ESLD awaiting lung transplantation and that the severity of reflux can impact survival.
METHODS: We conducted a retrospective analysis of all scleroderma patients referred for lung transplantation who underwent esophageal manometry and pH monitoring since August 2008. We identified 10 patients in whom we calculated and compared the area under the curve for each receiver operating characteristic curve of the following variables: DeMeester score, forced expiratory volume in 1 s (FEV1), %predicted FEV1, forced vital capacity (FVC), %predicted FVC, diffusion capacity for carbon monoxide (DLco), and %predicted DLco.
RESULTS: The DeMeester score nominally outperformed FEV1, FVC, and DLco. Receiver operating characteristic curve analysis was also used to define the optimal DeMeester score (65.2) in differentiating survival status, as determined by maximizing sensitivity and specificity. Based on this value, we calculated the 1-y survival from the time of the esophageal function testing, which was 100% in seven patients with a DeMeester score of <65.2, and 33% in three patients with a score >65.2 (P = 0.01). The latter patients had greater total time pH < 4, greater time pH < 4 in the supine position, greater total episodes of reflux, and higher prevalence of absent peristalsis. The single survivor with a DeMeester score >70 had also proximal reflux, underwent antireflux surgery, and is alive 1201 d after transplant.
CONCLUSIONS: Our study shows that esophageal pH monitoring can predict survival status in patients with scleroderma awaiting lung transplantation and that the severity of reflux can impact the 1-y survival rate. Therefore, esophageal pH monitoring should be considered early in patients with scleroderma and ESLD, as this test could appropriately identify those in whom laparoscopic antireflux surgery should be performed quicker to prevent GERD and its detrimental effects in patients awaiting lung transplantation.