The added diagnostic value of postreflux swallow-induced peristaltic wave index and nocturnal baseline impedance in refractory reflux disease studied with on-therapy impedance-pH monitoring.
BACKGROUND
On-therapy impedance-pH monitoring in proton pump inhibitor (PPI)-refractory gastroesophageal reflux disease (GERD) yielded conflicting results. We aimed to assess the diagnostic value of postreflux swallow-induced peristaltic wave (PSPW) index and mean nocturnal baseline impedance (MNBI) in PPI-refractory heartburn.


METHODS
On-therapy impedance-pH tracings from 189 consecutive patients with PPI-refractory heartburn were blindly reviewed. Patients were subdivided into refractory reflux esophagitis (RRE), healed reflux esophagitis (HRE), non-erosive reflux disease (NERD), and functional heartburn (FH) according to endoscopic and conventional impedance-pH findings. The diagnostic accuracy of PSPW index and MNBI in separating NERD from FH was assessed with receiver-operating-characteristic (ROC) analysis. Objectively documented persistent reflux remission at 3-year follow-up in 53 patients who underwent laparoscopic fundoplication served to evaluate PSPW index and MNBI as independent predictors of PPI-refractory GERD confirmed by positive surgical outcome.


RESULTS
Median PSPW index and MNBI values were significantly lower in 39 RRE (16%; 1145 Ω) than in 41 HRE (25%; 1741 Ω) and in 68 NERD (29%; 2374 Ω) patients, and in all three GERD subgroups compared to 41 FH cases (67%; 3488 Ω) (P<.008). At ROC analysis, comparing NERD to FH the area under the curve was 0.886 with PSPW index and 0.677 with MNBI (P=.005). PSPW index was an independent predictor of PPI-refractory GERD (odds ratio 0.6983, P=.012).


CONCLUSIONS
At on-therapy impedance-pH monitoring, PSPW index and MNBI efficiently distinguish PPI-refractory NERD from FH. The PSPW index represents an independent predictor of PPI-refractory GERD.
Digestive Pathophysiology Unit, Baggiovara Hospital, Modena, Italy.
M
M
Frazzoni
Department of Translational Research and New Technology in Medicine and Surgery, University of Pisa, Pisa, Italy.
N
N
de Bortoli
Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy.
L
L
Frazzoni
General and Bariatric Surgery Unit, Department of Surgery, 2nd University of Napoli, Naples, Italy.
S
S
Tolone
Gastroenterology Unit, Department of Internal Medicine, University of Genova, Genova, Italy.
M
M
Furnari
Department of Translational Research and New Technology in Medicine and Surgery, University of Pisa, Pisa, Italy.
I
I
Martinucci
Digestive Pathophysiology Unit, Baggiovara Hospital, Modena, Italy.
V G
VG
Mirante
Department of Translational Research and New Technology in Medicine and Surgery, University of Pisa, Pisa, Italy.
S
S
Marchi
Gastroenterology Unit, Department of Internal Medicine, University of Genova, Genova, Italy.
V
V
Savarino
Gastroenterology Unit, Department of Surgery, Oncology and Gastroenterology, University of Padova, Padova, Italy.
E
E
Savarino
D000328:Adult; D003679:Deglutition / Q000502:physiology*; D017097:Electric Impedance; D050782:Esophageal pH Monitoring / Q000379:methods*; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis / Q000503:physiopathology*; D006356:Heartburn / Q000175:diagnosis / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010528:Peristalsis / Q000502:physiology*; D012189:Retrospective Studies
esophageal baseline impedance; esophageal chemical clearance; impedance-pH monitoring; refractory GERD