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Literature ReviewLiterature Review

Peter R. McNally, DO, FACP, FACGPeter R. McNally, DO, FACP, FACGLone Tree, ColoradoLone Tree, Colorado

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Four-day Bravo pH capsule monitoring with and Four-day Bravo pH capsule monitoring with and

without proton pump inhibitor therapywithout proton pump inhibitor therapy.. Hirano I, Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.Gastroenterology and Hepatology 2005;3:1083-1088.

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IntroductionIntroduction

• Ambulatory pH testing is considered the most Ambulatory pH testing is considered the most objective means of diagnosing gastroesophageal objective means of diagnosing gastroesophageal reflux disease (GERD). reflux disease (GERD).

• Limitations of conventional catheter-based pH Limitations of conventional catheter-based pH testing include patient tolerance, potential for testing include patient tolerance, potential for catheter migration, and limitation of “usual” catheter migration, and limitation of “usual” patient physiologic and dietary activity. patient physiologic and dietary activity.

• The Bravo wireless pH capsule (Medtronic, The Bravo wireless pH capsule (Medtronic, Shoreview, MN) has overcome these barriers and Shoreview, MN) has overcome these barriers and has the additional advantage of allowing for 48has the additional advantage of allowing for 48++ hour recording periods.hour recording periods.

Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.

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Study PurposeStudy Purpose

• Ambulatory pH testing is often used to guide the Ambulatory pH testing is often used to guide the management of reflux symptoms that do not management of reflux symptoms that do not respond to proton pump inhibitor (PPI) therapy respond to proton pump inhibitor (PPI) therapy and to evaluate the contribution of acid reflux to and to evaluate the contribution of acid reflux to atypical reflux symptoms (chest pain, cough, atypical reflux symptoms (chest pain, cough, hoarseness, throat tightness and asthma).hoarseness, throat tightness and asthma).

• Controversy exists on whether such clinical Controversy exists on whether such clinical studies should be conducted on or off PPI. This studies should be conducted on or off PPI. This pilot study aimed to evaluate the feasibility of 4-pilot study aimed to evaluate the feasibility of 4-day pH recordings using a single Bravo pH day pH recordings using a single Bravo pH capsule, encompassing the pre and intra-capsule, encompassing the pre and intra-treatment periods with PPI.treatment periods with PPI.

Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.

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Study DesignStudy Design• 18 patients with variety of symptoms to 18 patients with variety of symptoms to

include refractory GERD, chest pain, or include refractory GERD, chest pain, or chronic cough were included in the study. chronic cough were included in the study.

• Using Using twotwo separate receivers calibrated to separate receivers calibrated to a single Bravo pH capsule -- 4 day a single Bravo pH capsule -- 4 day monitoring. monitoring.

• Rabeprazole was administered on days 2-Rabeprazole was administered on days 2-4 of the study (20 mg orally twice daily).4 of the study (20 mg orally twice daily).

Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.

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Study MeasurementsStudy Measurements

• % time pH < 4 per 24 hrs% time pH < 4 per 24 hrs• Symptom index scoreSymptom index score• Correlation symptoms & acid refluxCorrelation symptoms & acid reflux• Effect of Rabebrazole on acid Effect of Rabebrazole on acid

reflux events Day 2, 3, 4.reflux events Day 2, 3, 4.

Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.

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ResultsResults

• Bravo pH capsule functioned for 4 days in 16 of 18 Bravo pH capsule functioned for 4 days in 16 of 18 (89%) patients (capsule detachment at day-2 in (89%) patients (capsule detachment at day-2 in one patient and day-3 in another). one patient and day-3 in another).

• 9 of 16 (53%) of patients had acid exposure 9 of 16 (53%) of patients had acid exposure exceeding 4% on day-1.exceeding 4% on day-1.

• Patients showed significant and progressive Patients showed significant and progressive reductions in acid exposure on days 2-4 of the reductions in acid exposure on days 2-4 of the recording period.recording period.

• Six of 7 (87%) patients with abnormal acid reflux Six of 7 (87%) patients with abnormal acid reflux exposure on day-1, normalized by day-3. exposure on day-1, normalized by day-3.

Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.

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ResultsResults• 7 pts with chest pain7 pts with chest pain

– 1/7 had >50% correlation acid events and pain1/7 had >50% correlation acid events and pain

• 3 pts with chronic cough3 pts with chronic cough– 0/3 had correlation with acid events and cough0/3 had correlation with acid events and cough

• 7 pts with refractory heartburn7 pts with refractory heartburn– 1/7 patients failed to normalize acid exposure after 4 1/7 patients failed to normalize acid exposure after 4

days of Rabebrazoledays of Rabebrazole

Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.

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ConclusionsConclusions

• Prolonged esophageal pH Prolonged esophageal pH recording using the Bravo pH recording using the Bravo pH system is feasible.system is feasible.

• Prolonged pH recording will allow Prolonged pH recording will allow for testing both off and on a for testing both off and on a therapeutic trial of PPI. therapeutic trial of PPI.

Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.

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Reviewer CommentsReviewer Comments

We can anticipate more studies using this prolonged We can anticipate more studies using this prolonged pH capsule testing among patients with:pH capsule testing among patients with:

Persistent GERD symptoms despite use of PPIPersistent GERD symptoms despite use of PPIAtypical GERD (chest pain, asthma, hoarseness, Atypical GERD (chest pain, asthma, hoarseness, globus)globus)Severe erosive GERDSevere erosive GERDBarrett’s esophagusBarrett’s esophagusRecurrent Peptic strictureRecurrent Peptic stricture

Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:1083-1088.