AnxietyNCT07381023
Using Breathing Techniques to Ease Anxiety in ICU Patients Awaiting Heart Transplants
A study testing Heart Rate Variability Biofeedback (HRVB) in people with Anxiety and Heart Transplant Patients, run by Hartford HealthCare.
Trial summary
The goal of this clinical trial is to learn whether a breathing-based relaxation technique called heart rate variability biofeedback (HRVB) can help reduce anxiety in adult patients who are in the intensive care unit (ICU) and waiting for a heart transplant. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Anxiety, Heart Transplant Patients
- What is being tested?
- Heart Rate Variability Biofeedback (HRVB)
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- No sites listed yet
- Study dates
- Mar 2026to Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- any gender
- any race/ethnicity
- ≥18 years old with no upper limit
- currently inpatient in the cardiac ICU, awaiting heart transplant
- elevated anxiety symptoms as evidenced by cut scores on the Depression, Anxiety and Stress Scale (DASS-21) and the Cardiac Anxiety Questionnaire (CAQ) (Lovibond \& Lovibond, 1995; Eifert et al., 2000).
- proficiency in speaking, reading and writing in English Participants in this study must be proficient in English due to the language limitations of the study administrator. The intervention includes a teaching component that requires verbal instruction, psychoeducation, and interactive engagement, all of which will be conducted exclusively in English. At this time, the study administrator is only proficient in English and is unable to reliably deliver the intervention or assess participant understanding in other languages. To ensure consistency, accuracy, and fidelity of the intervention, as well as to maintain ethical standards in informed consent and participant comprehension, only English-speaking individuals will be eligible to participate.
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- able/willing to consent to participate Exclusion Criteria
- <18 years of age
- active psychosis or delirium
- current neurological problems (e.g., stroke) at time of enrollment that would interfere with the ability to complete the practice
- on a ventilator at time of enrollment
- pregnancy
- unable or unwilling to consent to participate
Who cannot join
None listed.
About this study
Official title: Effectiveness of Heart Rate Variability in Reducing Anxiety in Pre-Heart Transplant Candidates in the ICU
The goal of this clinical trial is to learn whether a breathing-based relaxation technique called heart rate variability biofeedback (HRVB) can help reduce anxiety in adult patients who are in the intensive care unit (ICU) and waiting for a heart transplant. The main questions it aims to answer are:
Can HRVB reduce anxiety in patients awaiting heart transplantation in the ICU? Does HRVB help patients feel more in control of their emotions during this stressful time?
Participants will:
Complete a brief anxiety assessment before and after the intervention Participate in a guided HRVB session using a breathing device or app Learn how to use the technique on their own for future stress management
Read the detailed description
This is a single-group clinical trial designed to evaluate the effectiveness of heart rate variability biofeedback (HRVB) in reducing anxiety among adult patients who are currently admitted to the intensive care unit (ICU) and awaiting heart transplantation. Patients in this population often experience elevated levels of psychological distress, including anxiety and panic symptoms, due to the uncertainty of their medical condition, the high-stress ICU environment, and the emotional burden of awaiting a life-saving procedure.
Heart rate variability (HRV) is a physiological marker of autonomic nervous system function and emotional regulation. HRVB is a non-invasive intervention that teaches individuals to regulate their breathing in a way that promotes optimal HRV. This technique has been shown in prior research to reduce anxiety and improve emotional resilience in various populations, but its application in critically ill transplant candidates remains underexplored.
Participants in this study will complete a baseline assessment of anxiety using validated self-report measures. They will then participate in a guided HRVB session, which includes paced breathing instruction and the use of a biofeedback device or app that provides real-time feedback on heart rate and breathing patterns. Following the session, participants will complete a post-intervention assessment to evaluate changes in anxiety levels. Participants will also be encouraged to continue practicing the technique independently as appropriate.
This study aims to assess the feasibility and immediate psychological benefits of HRVB in a high-acuity medical setting and to inform future research on integrative behavioral health interventions for transplant candidates.
- Conditions
- Anxiety, Heart Transplant Patients
- Being tested
- Heart Rate Variability Biofeedback (HRVB)
- Keywords
- Heart Transplant Candidates, Heart Rate Variability Biofeedback, Anxiety, Breathing techniques, Behavioral Health in Transplant, Cardiac Anxiety, Biofeedback Therapy
- Medical subject headings
- Anxiety Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Heart Rate Variability Biofeedback (HRVB)Behavioural
Participants will receive a single-session heart rate variability biofeedback (HRVB) intervention while admitted to the intensive care unit (ICU) as candidates for heart transplantation. The intervention involves guided paced breathing using a biofeedback device or app that provides real-time feedback on heart rate and breathing patterns. A trained clinician will lead the session, which is designed to promote autonomic regulation and reduce anxiety. Participants will complete pre- and post-intervention self-report assessments to evaluate changes in anxiety levels. They will also receive brief instruction on how to continue using the breathing technique independently.
| Study group | Role | What they receive |
|---|---|---|
| Heart Rate Variability Biofeedback for Anxiety Reduction in ICU Heart Transplant Candidates" | Experimental | Participants in this arm will receive a single-session heart rate variability biofeedback (HRVB) intervention while admitted to the intensive care unit (ICU) as candidates for heart transplantation. The intervention includes a guided breathing exercise using a biofeedback device or app that provides real-time feedback on heart rate and breathing patterns. A trained clinician will lead the session, which is designed to promote autonomic regulation and reduce anxiety. Participants will complete self-report anxiety assessments immediately before and after the session to evaluate changes in psychological distress. They will also receive brief instruction on how to continue using the breathing technique independently as appropriate. Receives: Behavioral: Heart Rate Variability Biofeedback (HRVB) |
What is being measured
The primary outcome is the main question the study is designed to answer.
DASS-21 Anxiety Scale (Depression Anxiety Stress Scales - 21-item short form)
Standardized self-report measure of anxiety Each item is scored 0-3. Each subscale (Depression, Anxiety, Stress) has 7 items → raw score 0-21, then multiplied by 2 to align with DASS-42 scoring.
Final score range per subscale: 0-42 (after multiplying) Higher scores = more severe symptoms.
Measured: Baseline (pre-intervention) and after 2 weeks (post-intervention)
Secondary outcomes (1)
Cardiac Anxiety Questionnaire
Standardized self-report measure of anxiety Contains 18 items, each rated on a 0-5 Likert scale (0 = never, 5 = always). Total score is the mean of all items. Minimum possible mean score: 0 Maximum possible mean score: 5 Higher CAQ scores = greater cardiac anxiety (worse outcome)
Measured: Baseline (pre-intervention) and after 2 weeks (post-intervention)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Feb 2026
- Study startMar 2026 (estimated)
- Primary completionNov 2027 (estimated)
- Study completionDec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AnxietyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hartford HealthCare
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Rachel Cavallaro, Hartford HealthCare
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07381023
- Sponsor's protocol ID
- HHC-2025-0188
- Status last verified
- Mar 2026
- First submitted
- 1 Oct 2025
- Last updated
- 27 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Only IPD used in the results publication
Study at a glance
From the registry record, last updated by the sponsor on 27 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effectiveness of Heart Rate Variability in Reducing Anxiety in Pre-Heart Transplant Candidates in the ICU
- ClinicalTrials.gov ID
- NCT07381023
- Acronym / sponsor ID
- HHC-2025-0188
- Conditions
- Anxiety, Heart Transplant Patients
- Keywords
- Heart Transplant Candidates, Heart Rate Variability Biofeedback, Anxiety, Breathing techniques, Behavioral Health in Transplant, Cardiac Anxiety, Biofeedback Therapy
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Hartford HealthCareUniversity, hospital or other
- Study start
- Mar 2026 (estimated)
- Primary completion
- Nov 2027 (estimated)
- Study completion
- Dec 2027 (estimated)
- First posted
- 2 Feb 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical trial is to learn whether a breathing-based relaxation technique called heart rate variability biofeedback (HRVB) can help reduce anxiety in adult patients who are in the intensive care unit (ICU) and waiting for a heart transplant. The main questions it aims to answer are:
Can HRVB reduce anxiety in patients awaiting heart transplantation in the ICU? Does HRVB help patients feel more in control of their emotions during this stressful time?
Participants will:
Complete a brief anxiety assessment before and after the intervention Participate in a guided HRVB session using a breathing device or app Learn how to use the technique on their own for future stress management
Detailed description
This is a single-group clinical trial designed to evaluate the effectiveness of heart rate variability biofeedback (HRVB) in reducing anxiety among adult patients who are currently admitted to the intensive care unit (ICU) and awaiting heart transplantation. Patients in this population often experience elevated levels of psychological distress, including anxiety and panic symptoms, due to the uncertainty of their medical condition, the high-stress ICU environment, and the emotional burden of awaiting a life-saving procedure.
Heart rate variability (HRV) is a physiological marker of autonomic nervous system function and emotional regulation. HRVB is a non-invasive intervention that teaches individuals to regulate their breathing in a way that promotes optimal HRV. This technique has been shown in prior research to reduce anxiety and improve emotional resilience in various populations, but its application in critically ill transplant candidates remains underexplored.
Participants in this study will complete a baseline assessment of anxiety using validated self-report measures. They will then participate in a guided HRVB session, which includes paced breathing instruction and the use of a biofeedback device or app that provides real-time feedback on heart rate and breathing patterns. Following the session, participants will complete a post-intervention assessment to evaluate changes in anxiety levels. Participants will also be encouraged to continue practicing the technique independently as appropriate.
This study aims to assess the feasibility and immediate psychological benefits of HRVB in a high-acuity medical setting and to inform future research on integrative behavioral health interventions for transplant candidates.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Heart Rate Variability Biofeedback for Anxiety Reduction in ICU Heart Transplant Candidates" | Experimental | Behavioral: Heart Rate Variability Biofeedback (HRVB)Participants in this arm will receive a single-session heart rate variability biofeedback (HRVB) intervention while admitted to the intensive care unit (ICU) as candidates for heart transplantation. The intervention includes a guided breathing exercise using a biofeedback device or app that provides real-time feedback on heart rate and breathing patterns. A trained clinician will lead the session, which is designed to promote autonomic regulation and reduce anxiety. Participants will complete self-report anxiety assessments immediately before and after the session to evaluate changes in psychological distress. They will also receive brief instruction on how to continue using the breathing technique independently as appropriate. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (13 listed)
- any gender
- any race/ethnicity
- ≥18 years old with no upper limit
- currently inpatient in the cardiac ICU, awaiting heart transplant
- elevated anxiety symptoms as evidenced by cut scores on the Depression, Anxiety and Stress Scale (DASS-21) and the Cardiac Anxiety Questionnaire (CAQ) (Lovibond \& Lovibond, 1995; Eifert et al., 2000).
Key exclusion criteria (0 listed)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Heart Rate Variability Biofeedback (HRVB)Participants will receive a single-session heart rate variability biofeedback (HRVB) intervention while admitted to the intensive care unit (ICU) as candidates for heart transplantation. The intervention involves guided paced breathing using a biofeedback device or app that provides real-time feedback on heart rate and breathing patterns. A trained clinician will lead the session, which is designed to promote autonomic regulation and reduce anxiety. Participants will complete pre- and post-intervention self-report assessments to evaluate changes in anxiety levels. They will also receive brief instruction on how to continue using the breathing technique independently. | Behavioural | Heart Rate Variability Biofeedback for Anxiety Reduction in ICU Heart Transplant Candidates" |
Primary outcome
DASS-21 Anxiety Scale (Depression Anxiety Stress Scales - 21-item short form)
Time frame: Baseline (pre-intervention) and after 2 weeks (post-intervention)
Standardized self-report measure of anxiety Each item is scored 0-3. Each subscale (Depression, Anxiety, Stress) has 7 items → raw score 0-21, then multiplied by 2 to align with DASS-42 scoring. Final score range per subscale: 0-42 (after multiplying) Higher scores = more severe symptoms.
1 secondary outcome
Cardiac Anxiety Questionnaire
Time frame: Baseline (pre-intervention) and after 2 weeks (post-intervention)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Mar 2026.
- Individual participant dataSharing planned: Yes. Only IPD used in the results publication
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
The record lists no contact. Use the official record to reach the sponsor.
Questions about this trial
What is this clinical trial studying?
A study testing Heart Rate Variability Biofeedback (HRVB) in people with Anxiety and Heart Transplant Patients, run by Hartford HealthCare.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 13 inclusion and 0 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 27 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
DASS-21 Anxiety Scale (Depression Anxiety Stress Scales - 21-item short form) (time frame: Baseline (pre-intervention) and after 2 weeks (post-intervention)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Mar 2026.