24-hour ambulatory pH-metry in patients with refractory heartburn: a prospective study

Gastroesophageal reflux disease (GERD) is a chronic condition that affects a large proportion of population. The aim of our study was to determine what percentages of patients with persistent heartburn on acid suppressive therapy have evidence of reflux disease while off acid suppressive therapy.

In a prospective study 48 patients with refractory heartburn from Taleghani Hospital were enrolled who had been on a double dose of proton pump inhibitor (PPI) for 8 weeks without improvement. Because of low index of suspicion for GERD as an etiology, all the patients underwent 24h pH-metry while off PPI. The variables of pH-metry such as the fraction time of pH <4 were evaluated by comparing to normal volunteers.

The mean "number of acid refluxes" was 49.98 in upright position and 6.29 in supine position. The mean "longest acid reflux" duration was 2.98 minutes in upright and 3.13 minutes in supine position. The total time fraction of pH <4 was 2.97% in upright position, 1.2 % in supine position and 2.74% in postprandial state. The mean DeMeester score was 10.06 (SD=10.48). However, the difference in the total fraction of time with pH <4 was not significant.

Our study showed that most of the patients with refractory heartburn did not have acid reflux. Patients with refractory heartburn often do not have evidence of reflux disease on pH monitoring, thus evaluating these patients should be performed while on acid suppressive therapy (using impedance-pH monitoring) in order to clarify the relationship between symptoms and acid and non-acid reflux.