P2033 - Characterization of Gastric Contractility Using the Atmo Capsule: Differences in Contractile Amplitude Based on Gastric Phase and Transit Delay

Award: ACG Presidential Poster Award

William L.. Hasler, MD¹, Thomas Abell, MD², Ashok Attaluri, MD³, William Chey, MD, FACG⁴, Michael Cline, DO⁵, Vincent Ho, MD⁶, Allen Lee, MD, MS⁷, Anthony Lembo, MD, FACG⁸, Amir Masoud, MD⁹, Richard McCallum, MD, FACG¹⁰, Baha Moshiree, MD¹¹, Eamonn M.. Quigley, MD, MACG¹², Satish SC. Rao, MD, PhD, FACG¹³, Abigail Stocker, MD², Mayra Sanchez, MD¹⁴, Irene Sarosiek, MD¹⁰, Brian Surjanhata, MD¹⁵, Jerry Zhou, PhD⁶, Braden Kuo, MD¹⁶
1Mayo Clinic Arizona, Scottsdale, AZ; 2University of Louisville, Louisville, KY; 3University of Kansas Health System, Olathe, KS; 4University of Michigan Health, Ann Arbor, MI; 5Cleveland Clinic, Cleveland, OH; 6Western Sydney University, Campbelltown, New South Wales, Australia; 7University of Michigan Medical School, Ann Arbor, MI; 8Cleveland Clinic Foundation, Cleveland, OH; 9Hartford Healthcare/Connecticut GI, Fairfield, CT; 10Texas Tech University Health Sciences Center, El Paso, TX; 11Atrium Health Carolinas Medical Center, Charlotte, NC; 12Houston Methodist Hospital, Houston, TX; 13Augusta University Medical Center, Augusta, GA; 14Hartford HealthCare's Neurogastroenterology and Motility Center, Fairfield, CT; 15Massachusetts General Hospital, Harvard Medical School, Boston, MA; 16Center for Neurointestinal Health, Massachusetts General Hospital, Boston, MA

Introduction: Gastric contractions occur at a frequency of ~3 cycles per minute (cpm) in phase with gastric slow waves. These contractions occur at high amplitude in the fed state to aid digestion, and less frequently or at lower amplitudes in the fasted state, until progression toward phase III of the migrating motor complex. Weaker gastric contractions have been implicated in delayed gastric emptying. The Atmo Capsule possesses an onboard accelerometer that can detect contractions by measuring changes in capsule orientation. We analyzed the accelerometer data of the Atmo Capsule to interrogate its ability to measure gastric contractions in different gastric phases, and how they relate to delayed gastric transit.

Methods: Gut transit was measured by the Atmo Capsule in 209 patients with suspected dysmotility. This analysis utilized data from patients with valid transit and accelerometer measures in the stomach. Gastric emptying times (GET) ≥5h were considered delayed. Fast Fourier Transformation of the accelerometer data using 5min windows and a cutoff frequency of 4.5cpm allowed the dominant gastric contraction frequency and amplitudes to be identified. The contraction frequency and amplitudes (as arbitrary units) were assessed across 60min following meal ingestion and 60min before gastric emptying of the capsule indicative of early and late gastric phases, and in relation to GET delay.

Results: Delayed GET was observed in 57/187 (30%) patients. Contraction frequencies in early and late gastric phases were similar in patients with normal (3.1cpm for both) and delayed GET (3.0cpm for both) (p >0.05 for both) (Fig 1). Contraction amplitudes in the early gastric phase were similar between patients with normal (11.7 [9.1-14.4]) and delayed GET (12.5 [8.7-14.9]) (p >0.05). In the late gastric phase, contraction amplitudes were higher in patients with normal (9.2 [7.5-12.2]) compared with delayed GET (6.4 [4.2-8.7]) (p< 0.01).

Discussion: The Atmo Capsule accelerometer provided a reproducible characterization of the frequency and amplitude of gastric contractions in patients with suspected dysmotility, showing that contraction amplitude was lower in the late compared with early phase of gastric residence. This difference was more pronounced in those with delayed GET, suggesting there may be differences in fasting antral activity in relation to gastric transit. These findings indicate that the device may offer additional clinical utility for evaluating gastric physiology beyond assessment of transit time.


Figure: Mean gastric contractile frequency (A-B; cycles per minute) and amplitude (C-D; arbitrary units) in early (60-min post-ingestion) and late (60-min pre-gastric emptying) gastric phases (as analyzed via Mann-Whitney).

Disclosures:
William Hasler: Alimetry Ltd. – Grant/Research Support. Atmo Biosciences – Grant/Research Support. Enterra Medical – Advisory Committee/Board Member, Grant/Research Support.
Thomas Abell: Adept gi – Owner/Ownership Interest. Enterra Medical – Consultant. Novo Nordsk – Consultant. Nuvaira – Consultant. Up To Date – Royalties. Vanda – Consultant.
Ashok Attaluri indicated no relevant financial relationships.
William Chey: Ardelyx – Consultant. Atmo – Consultant. Biomerica – Consultant. Commonwealth Diagnostics International – Grant/Research Support. Coprata – Stock Options. Dieta – Stock Options. Digital Manometry – Intellectual Property/Patents. Evinature – Stock Options. FoodMarble – Stock Options. Gemelli – Consultant. Kiwi BioScience – Stock Options. Modify Health – Stock Options. My Nutrition Health – Intellectual Property/Patents. Phathom – Consultant. Rectal Expulsion Device – Intellectual Property/Patents. Redhill – Consultant. Salix – Consultant, Grant/Research Support. Takeda – Consultant. Vibrant – Consultant.
Michael Cline: EVOKE Pharmaceuticals – Key Opinion Leader. Kate Farms – Key Opinion Leader.
Vincent Ho indicated no relevant financial relationships.
Allen Lee: Atmo Biosciences – Consultant.
Anthony Lembo: Allurion – Stock-publicly held company(excluding mutual/index funds). Ardeylx – Consultant. Atmo – Advisory Committee/Board Member. Bristol Myer Squibb – Stock-publicly held company(excluding mutual/index funds). GSK – Consultant. Ironwood – DSMB. J&J – Stock-publicly held company(excluding mutual/index funds). Salix – Consultant. Takeda – Consultant. Vibrant – Consultant.
Amir Masoud indicated no relevant financial relationships.
Richard McCallum indicated no relevant financial relationships.
Baha Moshiree indicated no relevant financial relationships.
Eamonn Quigley: Food Marble – Advisor or Review Panel Member.
Satish Rao: Laborie Medical Technologies – Grant/Research Support. Vibrant Ltd – Advisory Committee/Board Member.
Abigail Stocker: Atmos – Grant/Research Support. CinDome – Grant/Research Support. Enterra Medical – Grant/Research Support. Vanda Pharmaceuticals – Grant/Research Support.
Mayra Sanchez indicated no relevant financial relationships.
Irene Sarosiek indicated no relevant financial relationships.
Brian Surjanhata indicated no relevant financial relationships.
Jerry Zhou indicated no relevant financial relationships.
Braden Kuo: Atmo – Consultant. Cindome – Consultant. ClinRx Pharma – Consultant. Evoke – Consultant. Genzynme – Consultant. GI Foundation – Consultant. Ironwood – Consultant. Medtronic – Consultant. Neurogastrx – Consultant. Novo – Consultant. Phathom – Consultant. Takeda – Consultant.

William L.. Hasler, MD¹, Thomas Abell, MD², Ashok Attaluri, MD³, William Chey, MD, FACG⁴, Michael Cline, DO⁵, Vincent Ho, MD⁶, Allen Lee, MD, MS⁷, Anthony Lembo, MD, FACG⁸, Amir Masoud, MD⁹, Richard McCallum, MD, FACG¹⁰, Baha Moshiree, MD¹¹, Eamonn M.. Quigley, MD, MACG¹², Satish SC. Rao, MD, PhD, FACG¹³, Abigail Stocker, MD², Mayra Sanchez, MD¹⁴, Irene Sarosiek, MD¹⁰, Brian Surjanhata, MD¹⁵, Jerry Zhou, PhD⁶, Braden Kuo, MD¹⁶. P2033 - Characterization of Gastric Contractility Using the Atmo Capsule: Differences in Contractile Amplitude Based on Gastric Phase and Transit Delay, ACG 2025 Annual Scientific Meeting Abstracts. Phoenix, AZ: American College of Gastroenterology.