Different Loop Gain Phenotypes in Patients With Chronic Systolic Heart Failure and Periodic Breathing

Sponsor
Wissenschaftliches Institut Bethanien e.V (Other)
Overall Status
Completed
CT.gov ID
NCT03532412
Collaborator
(none)
12
1
4.6
2.6

Study Details

Study Description

Brief Summary

Central sleep apnoea (CSA) is common in patients with chronic systolic heart failure (HFrEF). Various trials have shown a prevalence of 21 - 37% in this group of people. Up to 66% of patients with CSA and HFrEF present with periodic breathing (PB), which is considered being a marker of HF severity and poor prognosis. Brack et al. summarized data from cohorts, longitudinal studies and retrospective analyses showing an independently increased risk of death in HF patients with PB (HR 2.1-5.7 in five of seven studies). Furthermore, PB in HF patients is known to reduce quality of life and exercise performance and to increase sympathetic nerve activity as well as the probability of malignant cardiac arrhythmias.

The pathogenesis of PB is characterized by an instability of ventilatory drive. The level of carbon dioxide (CO2) in blood and cerebrospinal fluid correlates linearly with minute ventilation. A high level of CO2 increases ventilation while hypocapnia dampens it. This control theory is based on the loop gain (LG), which represents the sensitivity and reactivity of the ventilatory system and comprises three components: The plant gain defines the capacity of the system to change PaCO2 in response to a change in ventilation (metabolic response). It is influenced by the lung volume as well as the anatomy of the thorax and the upper airways. The feedback gain is defined by the chemoreceptor responsiveness in reaction to blood gas changes. The controller gain is represented by the respiratory control center in the brain stem and defines the capacity of the system to change ventilation in response to a change in PaCO2 (ventilatory response).

Sands et al. proposed and validated a mathematical model based on the ventilatory cycle pattern that quantifies the feedback loop. The ratio of ventilatory and cycle duration within the PB pattern is defined as the duty ratio (DR), which is the basis to calculate the LG. Any temporary breathing disturbance causing a PB pattern with a LG < 1 stabilizes within a few breathing cycles. A LG > 1 represents an unstable ventilatory response and slight changes of CO2 are accompanied by overshooting and undershooting of the ventilation. In that case, the polysomnography shows the typical pattern of waxing and waning of the tidal volume and effort.

HF patients typically present with an increased LG due to an impaired left ventricular function and a hyperstimulation of pulmonary vagal receptors. Furthermore, Khoo showed an increased chemosensitivity (controller gain) as well as a decreased ventilatory capacity (plant gain) in this group of people.

Sands and colleagues characterized PB considering the mean LG derived from several ventilatory cycles during non-REM sleep. This retrospective study of PB in HFrEF patients addresses the following questions:

  1. Is a single LG value appropriate to characterize the individual PB?

  2. Does the LG depend on sleep stage and body position?

  3. Does the intraindividual LG variability allow for the discrimination of different PB phenotypes and, if so, do these phenotypes differ in further characteristics?

Condition or Disease Intervention/Treatment Phase

    Study Design

    Study Type:
    Observational
    Actual Enrollment :
    12 participants
    Observational Model:
    Cohort
    Time Perspective:
    Retrospective
    Official Title:
    Different Loop Gain Phenotypes in Patients With Chronic Systolic Heart Failure and Periodic Breathing
    Actual Study Start Date :
    Jun 28, 2016
    Actual Primary Completion Date :
    Nov 14, 2016
    Actual Study Completion Date :
    Nov 14, 2016

    Arms and Interventions

    Arm Intervention/Treatment
    HF+CSA+PB

    Systolic heart failure with predominant central sleep apnea and periodic breathing

    Outcome Measures

    Primary Outcome Measures

    1. Loop Gain [During one day of diagnostic polysomnography]

      Mathematically determined loop gain of periodic breathing according to Sands et al. [10] based on diagnostic polysomnography

    Eligibility Criteria

    Criteria

    Ages Eligible for Study:
    N/A and Older
    Sexes Eligible for Study:
    All
    Accepts Healthy Volunteers:
    No
    Inclusion Criteria:
    • Systolic heart failure with left-ventricular ejection fraction <45%

    • Apnea-Hypopnea index >15 per hour as determined by diagnostic polysomnography

    • Predominant central sleep apnea as defined by >50% central respiratory events

    Exclusion Criteria:
    • <50 evaluable respiratory events for loop gain analysis during diagnostic polysomnography

    Contacts and Locations

    Locations

    Site City State Country Postal Code
    1 Wissenschaftliches Institut Bethanien für Pneumologie e.V. Solingen Germany 42699

    Sponsors and Collaborators

    • Wissenschaftliches Institut Bethanien e.V

    Investigators

    • Principal Investigator: Winfried J Randerath, Prof. Dr., Director

    Study Documents (Full-Text)

    None provided.

    More Information

    Publications

    Responsible Party:
    Wissenschaftliches Institut Bethanien e.V
    ClinicalTrials.gov Identifier:
    NCT03532412
    Other Study ID Numbers:
    • WI_LoopGain
    First Posted:
    May 22, 2018
    Last Update Posted:
    May 22, 2018
    Last Verified:
    May 1, 2018
    Individual Participant Data (IPD) Sharing Statement:
    No
    Plan to Share IPD:
    No
    Studies a U.S. FDA-regulated Drug Product:
    No
    Studies a U.S. FDA-regulated Device Product:
    No
    Keywords provided by Wissenschaftliches Institut Bethanien e.V
    Additional relevant MeSH terms:

    Study Results

    No Results Posted as of May 22, 2018