Coronary Artery Bypass Grafting (CABG) SurgeryENVNCT07853222
Vagus Nerve Stimulation for Autonomic Modulation After Coronary Artery Bypass Graft Surgery
A study testing Transcutaneous auricular vagus nerve stimulation in people with Coronary Artery Bypass Grafting (CABG) Surgery and Vagus Nerve Stimulations, run by Hospital de Clinicas de Porto Alegre at 2 sites in Brazil.
Trial summary
The objective of this randomized clinical trial is to investigate whether transcutaneous auricular vagus nerve stimulation (taVNS) can improve the recovery of patients undergoing coronary artery bypass grafting (CABG) through autonomic modulation, while also evaluating the safety of the intervention. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Coronary Artery Bypass Grafting (CABG) Surgery, Vagus Nerve Stimulations
- What is being tested?
- Transcutaneous auricular vagus nerve stimulation
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 58 participants
- Where
- 2 sitesBrazil
- Study dates
- 31 Aug 2025to 30 Jun 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
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
None listed.
Who cannot join
- History of severe cardiac arrhythmias or recent electrical instability, including permanent atrial fibrillation, tachyarrhythmias, or the presence of an implantable cardioverter-defibrillator (ICD).
- Presence of a pacemaker or other implanted electronic devices.
- Severe neurological or psychiatric disorders, such as epilepsy, schizophrenia, or recent stroke (within the past 6 months).
- Active chronic inflammatory or autoimmune diseases that may interfere with inflammatory markers (e.g., systemic lupus erythematosus or rheumatoid arthritis).
- Acute infection or fever at the time of screening.
- History of ear surgery or ear injury that would preclude the application of transcutaneous auricular vagus nerve stimulation (taVNS).
- Confirmed or suspected pregnancy (for female participants of childbearing potential).
Trial locations and contacts
2 sites in 1 country.
Brazil2 sites
Hospital de Clinicas de Ijuí
Ijuí, Rio Grande do Sul, 98700000
Hospital de Clinicas de Porto Alegre
Porto Alegre, Rio Grande do Sul, 90035-903
About this study
Official title: Vagus Nerve Stimulation for Autonomic Modulation in Patients Undergoing Coronary Artery Bypass Grafting: A Randomized Clinical Trial
The objective of this randomized clinical trial is to investigate whether transcutaneous auricular vagus nerve stimulation (taVNS) can improve the recovery of patients undergoing coronary artery bypass grafting (CABG) through autonomic modulation, while also evaluating the safety of the intervention.
The main questions this study aims to answer are:
Read more
- Does taVNS improve autonomic modulation, as assessed by heart rate variability, in patients undergoing CABG?
- Does taVNS reduce the inflammatory response and pain intensity while improving quality of life and functional capacity during the postoperative period?
- Is taVNS a safe and well-tolerated intervention during recovery after CABG? The researchers will compare taVNS with a control group (sham stimulation/placebo) to determine whether the intervention leads to better clinical and functional outcomes in patients undergoing coronary artery bypass grafting.
Participants will:
- Receive sessions of transcutaneous auricular vagus nerve stimulation (taVNS) or sham stimulation (placebo), according to the study randomization.
- Undergo assessments of autonomic modulation using heart rate variability before and after the intervention.
- Be evaluated for inflammatory markers, pain intensity, quality of life, and functional capacity at different time points during the postoperative period.
Read the detailed description
Coronary artery disease (CAD) is one of the leading causes of morbidity and mortality worldwide. Coronary artery bypass grafting (CABG) is frequently indicated in patients with advanced disease. However, the postoperative period is associated with autonomic dysfunction, characterized by increased sympathetic activity and reduced vagal tone, which may contribute to cardiovascular complications and prolonged recovery.
Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive technique that involves electrical stimulation of the auricular branch of the vagus nerve. By modulating autonomic activity, taVNS may represent a complementary approach to supporting postoperative recovery. However, evidence regarding its application in the immediate postoperative period following CABG remains limited.
This randomized controlled clinical trial aims to investigate the effects of taVNS on autonomic modulation in patients undergoing CABG, as well as to assess the safety and tolerability of the intervention.
The study will be coordinated by Hospital de Clínicas de Porto Alegre (HCPA), the sponsoring institution, while participant recruitment and data collection will be conducted at Hospital de Clínicas de Ijuí (HCI), the collaborating center.
Eligible participants will be randomly assigned to either an active stimulation group or a sham control group. Randomization will be performed using a random number sequence.
Participants assigned to the intervention group will receive transcutaneous auricular vagus nerve stimulation using the EL-30 device (NKL). The electrodes will be positioned on the left cymba conchae and the left earlobe. Stimulation will be delivered in daily 30-minute sessions throughout the hospital stay, using a pulse width of 250 μs, an intensity below the pain threshold, and alternating frequencies of 2 Hz and 15 Hz at 5-second intervals.
Participants in the control group will undergo the same procedure using the same device and electrode placement, but without active electrical stimulation. Each session will also last 30 minutes.
The intervention will begin during the postoperative period and will be administered under clinical supervision by trained healthcare professionals. Assessments will be conducted according to the study protocol, including measurements before and after stimulation sessions and at hospital discharge.
Heart rate variability (HRV) will be assessed using electrocardiography and a Polar H10 heart rate sensor. Recordings will be obtained with participants in the supine position after a 5-minute resting period, followed by 5-minute recordings.
The study will also include clinical and functional assessments during the postoperative period and at hospital discharge, according to the study protocol.
Potential risks associated with the intervention include mild discomfort, tingling, or itching at the stimulation site. Bradycardia may occur in susceptible individuals, who will be monitored during the procedure. Participants will be monitored throughout the intervention, and stimulation will be discontinued if clinically necessary.
The study will be conducted in accordance with applicable ethical standards and Brazilian regulations for research involving human participants. Written informed consent will be obtained before participation. Participant confidentiality and data privacy will be maintained throughout the study.
- Being tested
- Transcutaneous auricular vagus nerve stimulation
- Keywords
- Vagus Nerve Stimulation, Myocardial Revascularization, Autonomic Nervous System
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Transcutaneous auricular vagus nerve stimulationDevice
Transcutaneous auricular vagus nerve stimulation (taVNS) will be performed daily for 30 minutes until hospital discharge. One electrode will be placed on the auricular concha to stimulate the auricular branch of the vagus nerve, and the other electrode will be positioned on the left earlobe to stimulate the great auricular nerve. The stimulation will be delivered using the EL-30 device (NKL Produtos Eletrônicos, Brusque, SC, Brazil), with a pulse width of 250 μs, intensity below the pain threshold, and alternating frequencies of 2 Hz for 5 seconds and 15 Hz for 5 seconds. The stimulation sites were selected based on auricular innervation, technical feasibility, and treatment standardization.The control group will use the same device; however, no active electrical current will be delivered (placebo stimulation).
| Study group | Role | What they receive |
|---|---|---|
| Intervention Group | Active comparator | Transcutaneous auricular stimulation of the auricular branch of the vagus nerve with daily 30-minute sessions until hospital discharge.
A transcutaneous electrode will be positioned on the concha, and the other electrode on the left earlobe. In this manner, we will stimulate the vagus nerve at the concha and the great auricular nerve at the earlobe. These sites were selected based on the innervation of the ear, technical feasibility for electrode placement, and to standardize the treatment protocol.
In our study, the device used will be the EL-30 (NKL Produtos Eletrônicos, Brusque, SC, Brazil), with the following stimulation parameters: pulse width of 250 μs, intensity below the pain threshold, 5 seconds at 2 Hz / 5 seconds at 15 Hz. Recent studies have demonstrated that low frequencies have a greater effect on reducing sympathetic activity, whereas frequencies in the range of 10-25 Hz produce effective parasympathetic modulation. We selected a mixed mode, using both low (2 Hz) and me Receives: Device: Transcutaneous auricular vagus nerve stimulation |
| Control Group | Placebo comparator | The same device and electrodes used in the intervention group will be applied. No actual electrical current will be delivered. The session duration will be 30 minutes, with the same electrode placement and application positioning as the intervention group. Receives: Device: Transcutaneous auricular vagus nerve stimulation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Heart rate variability (HRV) assessed before and after each stimulation session until hospital discharge
Heart rate variability (HRV) measured immediately before and immediately after each daily stimulation session until hospital discharge.
Measured: Postoperative day 1 through hospital discharge. Stimulation will begin on postoperative day 1. HRV will be assessed immediately before and immediately after each daily stimulation session, from the first postoperative stimulation session until hospital
Secondary outcomes (6)
Quality of life assessed using the 36-Item Short Form Health Survey (SF-36).
The 36-Item Short Form Health Survey (SF-36) is used to assess health-related quality of life across eight domains: physical functioning, role limitations due to physical health, bodily pain, general health perceptions, vitality, social functioning, role limitations due to emotional problems, and mental health. Each domain is scored on a scale from 0 to 100, with 0 representing the worst health status and 100 representing the best health status. Higher scores indicate better health-related quality of life.
Measured: At hospital discharge following CABG.
Hospital complications (arrhythmias)
Occurrence of arrhythmias during the hospital stay following coronary artery bypass grafting (CABG), based on medical record documentation and/or cardiac monitoring during hospitalization.
Measured: From postoperative day 1 (POD 1) until hospital discharge.
Inflammatory Markers (C-Reactive Protein [CRP])
C-reactive protein (CRP) levels will be assessed as a marker of systemic inflammation following coronary artery bypass grafting (CABG). Measurements will be obtained once daily during the postoperative period.
Measured: From postoperative day 1 (POD 1) until hospital discharge, with daily measurements.
Pain Assessed Using the Visual Analog Scale (VAS)
Pain intensity will be assessed using the Visual Analog Scale (VAS), ranging from 0 to 10 points, where 0 = no pain (best outcome) and 10 = worst possible pain (worst outcome). Higher scores indicate greater pain intensity and a worse outcome, whereas lower scores indicate less pain and a better outcome.
Measured: From postoperative day 1 (POD 1) until hospital discharge, with daily assessments.
Functional Capacity Assessed by the Six-Minute Walk Test (6MWT)
Functional capacity will be assessed using the Six-Minute Walk Test (6MWT). The primary measure will be the distance walked, recorded in meters. A greater distance walked indicates better functional capacity.
Measured: At hospital discharge following coronary artery bypass grafting (CABG).
Hospital Length of Stay
Hospital length of stay will be calculated as the number of days from the date of coronary artery bypass grafting (CABG) to the date of hospital discharge.
Measured: From the date of coronary artery bypass grafting (CABG) until hospital discharge.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Oct 2026
- Study start31 Aug 2025
- Primary completion15 Jun 2026
- Study completion30 Jun 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (23)Papers the sponsor has linked to this study.
- Other trials for Coronary Artery Bypass Grafting (CABG) SurgeryStudies 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
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 58 participants (actual)
Sponsor and investigators
- Lead sponsor
- Hospital de Clinicas de Porto Alegre
- Sponsor type
- University, hospital or other
- Collaborators
- Hospital de Clinicas de Ijuí
- Responsible party
- Sponsor
- Investigators
- Ricardo Stein, Principal investigator, Hospital de Clínicas de Porto Alegre (HCPA)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07853222
- Sponsor's protocol ID
- 2025-0338
- Other IDs
- 90487825.4.1001.5327, 7.780.341
- Acronym
- ENV
- Status last verified
- Sep 2026
- First submitted
- 18 Sep 2026
- Last updated
- 1 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Couceiro SM, Sant'Anna LB, Sant'Anna MB, Menezes RSM, Mesquita ET, Sant'Anna FM. Auricular Vagal Neuromodulation and its Application in Patients with Heart Failure and Reduced Ejection Fraction. Arq Bras Cardiol. 2023 May 15;120(5):e20220581. doi: 10.36660/abc.20220581. eCollection 2023. English, Portuguese.
PubMed 37194830Harris PA, Taylor R, Minor BL, Elliott V, Fernandez M, O'Neal L, McLeod L, Delacqua G, Delacqua F, Kirby J, Duda SN; REDCap Consortium. The REDCap consortium: Building an international community of software platform partners. J Biomed Inform. 2019 Jul;95:103208. doi: 10.1016/j.jbi.2019.103208. Epub 2019 May 9.
PubMed 3107866021 DA SILVA, Roberto Léo et al. Avaliação da dor durante o cateterismo por via transradial utilizando Escala Visual Analógica. Revista Brasileira de Cardiologia Invasiva, v. 23, n. 3, p. 207- 210, 2015.
20 Kubios HRV - Software de análise de variabilidade da frequência cardíaca Tarvainen MP , Niskanen J.PLipponen JA , Ranta-aho PO , Karjalainen PA (2014) Métodos e Programas de Computador em Biomedicina , 113 (1), pp.
Himariotis AT, Coffey KF, Noel SE, Cornell DJ. Validity of a Smartphone Application in Calculating Measures of Heart Rate Variability. Sensors (Basel). 2022 Dec 15;22(24):9883. doi: 10.3390/s22249883.
PubMed 36560256Yang J, Ben-Menachem E. Accuracy and clinical utility of heart rate variability derived from a wearable heart rate monitor in patients undergoing major abdominal surgery. J Clin Monit Comput. 2024 Apr;38(2):433-443. doi: 10.1007/s10877-023-01080-8. Epub 2023 Oct 13.
PubMed 37831376Thygesen K, Alpert JS, Jaffe AS, Simoons ML, Chaitman BR, White HD; Joint ESC/ACCF/AHA/WHF Task Force for Universal Definition of Myocardial Infarction; Authors/Task Force Members Chairpersons; Thygesen K, Alpert JS, White HD; Biomarker Subcommittee; Jaffe AS, Katus HA, Apple FS, Lindahl B, Morrow DA; ECG Subcommittee; Chaitman BR, Clemmensen PM, Johanson P, Hod H; Imaging Subcommittee; Underwood R, Bax JJ, Bonow JJ, Pinto F, Gibbons RJ; Classification Subcommittee; Fox KA, Atar D, Newby LK, Galvani M, Hamm CW; Intervention Subcommittee; Uretsky BF, Steg PG, Wijns W, Bassand JP, Menasche P, Ravkilde J; Trials & Registries Subcommittee; Ohman EM, Antman EM, Wallentin LC, Armstrong PW, Simoons ML; Trials & Registries Subcommittee; Januzzi JL, Nieminen MS, Gheorghiade M, Filippatos G; Trials & Registries Subcommittee; Luepker RV, Fortmann SP, Rosamond WD, Levy D, Wood D; Trials & Registries Subcommittee; Smith SC, Hu D, Lopez-Sendon JL, Robertson RM, Weaver D, Tendera M, Bove AA, Parkhomenko AN, Vasilieva EJ, Mendis S; ESC Committee for Practice Guidelines (CPG); Bax JJ, Baumgartner H, Ceconi C, Dean V, Deaton C, Fagard R, Funck-Brentano C, Hasdai D, Hoes A, Kirchhof P, Knuuti J, Kolh P, McDonagh T, Moulin C, Popescu BA, Reiner Z, Sechtem U, Sirnes PA, Tendera M, Torbicki A, Vahanian A, Windecker S; Document Reviewers; Morais J, Aguiar C, Almahmeed W, Arnar DO, Barili F, Bloch KD, Bolger AF, Botker HE, Bozkurt B, Bugiardini R, Cannon C, de Lemos J, Eberli FR, Escobar E, Hlatky M, James S, Kern KB, Moliterno DJ, Mueller C, Neskovic AN, Pieske BM, Schulman SP, Storey RF, Taubert KA, Vranckx P, Wagner DR. Third universal definition of myocardial infarction. J Am Coll Cardiol. 2012 Oct 16;60(16):1581-98. doi: 10.1016/j.jacc.2012.08.001. Epub 2012 Sep 5. No abstract available.
PubMed 22958960Prasad K, Sharma V, Lackore K, Jenkins SM, Prasad A, Sood A. Use of complementary therapies in cardiovascular disease. Am J Cardiol. 2013 Feb 1;111(3):339-45. doi: 10.1016/j.amjcard.2012.10.010. Epub 2012 Nov 24.
PubMed 23186602Pires IM, Denysyuk HV, Villasana MV, Sa J, Marques DL, Morgado JF, Albuquerque C, Zdravevski E. Development Technologies for the Monitoring of Six-Minute Walk Test: A Systematic Review. Sensors (Basel). 2022 Jan 12;22(2):581. doi: 10.3390/s22020581.
PubMed 3506254214 Ciconelli, R M. Tradução para o português e validação do questionário genérico de avaliação de qualidade de vida "Medical Outcomes Study 36-Item Short- Form Health Survey (SF-36)". 1997. 148 p. Tese (Doutorado em Medicina) - Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, 1997.
13 PSS Health. Cálculo do tamanho amostral. Medidas. Acesso em: 22/04/2025. Disponível em:<https://hcpa-unidade-bioestatistica.shinyapps.io/PSS_Health/>
12 Villani, V., Tsagkaris, C., Dimitriadis, D., Zito, M., Anastasiou, A., & Giannopoulos, S. (2022). Effects of auricular vagus nerve stimulation on heart rate variability and autonomic balance. Autonomic Neuroscience, 240, 102964.
11 BAUER, S. et al. Transcutaneous vagus nerve stimulation (tVNS) in the treatment of depression: A randomized, double-blind, placebo-controlled pilot study. European Archives of Psychiatry and Clinical Neuroscience, v. 266, n. 8, p. 681-688, 2016.
Stavrakis S, Humphrey MB, Scherlag BJ, Hu Y, Jackman WM, Nakagawa H, Lockwood D, Lazzara R, Po SS. Low-level transcutaneous electrical vagus nerve stimulation suppresses atrial fibrillation. J Am Coll Cardiol. 2015 Mar 10;65(9):867-75. doi: 10.1016/j.jacc.2014.12.026.
PubMed 25744003Tracey KJ. The inflammatory reflex. Nature. 2002 Dec 19-26;420(6917):853-9. doi: 10.1038/nature01321.
PubMed 12490958
Study at a glance
From the registry record, last updated by the sponsor on 1 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Vagus Nerve Stimulation for Autonomic Modulation in Patients Undergoing Coronary Artery Bypass Grafting: A Randomized Clinical Trial
- ClinicalTrials.gov ID
- NCT07853222
- Acronym / sponsor ID
- ENV / 2025-0338
- Keywords
- Vagus Nerve Stimulation, Myocardial Revascularization, Autonomic Nervous System
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 58 participants (actual)
- Lead sponsor
- Hospital de Clinicas de Porto AlegreUniversity, hospital or other
- Collaborators
- Hospital de Clinicas de Ijuí
- Study start
- 31 Aug 2025 (actual)
- Primary completion
- 15 Jun 2026 (actual)
- Study completion
- 30 Jun 2026 (actual)
- First posted
- 1 Oct 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 objective of this randomized clinical trial is to investigate whether transcutaneous auricular vagus nerve stimulation (taVNS) can improve the recovery of patients undergoing coronary artery bypass grafting (CABG) through autonomic modulation, while also evaluating the safety of the intervention.
The main questions this study aims to answer are:
- Does taVNS improve autonomic modulation, as assessed by heart rate variability, in patients undergoing CABG?
- Does taVNS reduce the inflammatory response and pain intensity while improving quality of life and functional capacity during the postoperative period?
- Is taVNS a safe and well-tolerated intervention during recovery after CABG? The researchers will compare taVNS with a control group (sham stimulation/placebo) to determine whether the intervention leads to better clinical and functional outcomes in patients undergoing coronary artery bypass grafting.
Participants will:
- Receive sessions of transcutaneous auricular vagus nerve stimulation (taVNS) or sham stimulation (placebo), according to the study randomization.
- Undergo assessments of autonomic modulation using heart rate variability before and after the intervention.
- Be evaluated for inflammatory markers, pain intensity, quality of life, and functional capacity at different time points during the postoperative period.
Detailed description
Coronary artery disease (CAD) is one of the leading causes of morbidity and mortality worldwide. Coronary artery bypass grafting (CABG) is frequently indicated in patients with advanced disease. However, the postoperative period is associated with autonomic dysfunction, characterized by increased sympathetic activity and reduced vagal tone, which may contribute to cardiovascular complications and prolonged recovery.
Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive technique that involves electrical stimulation of the auricular branch of the vagus nerve. By modulating autonomic activity, taVNS may represent a complementary approach to supporting postoperative recovery. However, evidence regarding its application in the immediate postoperative period following CABG remains limited.
This randomized controlled clinical trial aims to investigate the effects of taVNS on autonomic modulation in patients undergoing CABG, as well as to assess the safety and tolerability of the intervention.
The study will be coordinated by Hospital de Clínicas de Porto Alegre (HCPA), the sponsoring institution, while participant recruitment and data collection will be conducted at Hospital de Clínicas de Ijuí (HCI), the collaborating center.
Eligible participants will be randomly assigned to either an active stimulation group or a sham control group. Randomization will be performed using a random number sequence.
Participants assigned to the intervention group will receive transcutaneous auricular vagus nerve stimulation using the EL-30 device (NKL). The electrodes will be positioned on the left cymba conchae and the left earlobe. Stimulation will be delivered in daily 30-minute sessions throughout the hospital stay, using a pulse width of 250 μs, an intensity below the pain threshold, and alternating frequencies of 2 Hz and 15 Hz at 5-second intervals.
Participants in the control group will undergo the same procedure using the same device and electrode placement, but without active electrical stimulation. Each session will also last 30 minutes.
The intervention will begin during the postoperative period and will be administered under clinical supervision by trained healthcare professionals. Assessments will be conducted according to the study protocol, including measurements before and after stimulation sessions and at hospital discharge.
Heart rate variability (HRV) will be assessed using electrocardiography and a Polar H10 heart rate sensor. Recordings will be obtained with participants in the supine position after a 5-minute resting period, followed by 5-minute recordings.
The study will also include clinical and functional assessments during the postoperative period and at hospital discharge, according to the study protocol.
Potential risks associated with the intervention include mild discomfort, tingling, or itching at the stimulation site. Bradycardia may occur in susceptible individuals, who will be monitored during the procedure. Participants will be monitored throughout the intervention, and stimulation will be discontinued if clinically necessary.
The study will be conducted in accordance with applicable ethical standards and Brazilian regulations for research involving human participants. Written informed consent will be obtained before participation. Participant confidentiality and data privacy will be maintained throughout the study.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Intervention Group | Active comparator | Device: Transcutaneous auricular vagus nerve stimulationTranscutaneous auricular stimulation of the auricular branch of the vagus nerve with daily 30-minute sessions until hospital discharge. A transcutaneous electrode will be positioned on the concha, and the other electrode on the left earlobe. In this manner, we will stimulate the vagus nerve at the concha and the great auricular nerve at the earlobe. These sites were selected based on the innervation of the ear, technical feasibility for electrode placement, and to standardize the treatment protocol. In our study, the device used will be the EL-30 (NKL Produtos Eletrônicos, Brusque, SC, Brazil), with the following stimulation parameters: pulse width of 250 μs, intensity below the pain threshold, 5 seconds at 2 Hz / 5 seconds at 15 Hz. Recent studies have demonstrated that low frequencies have a greater effect on reducing sympathetic activity, whereas frequencies in the range of 10-25 Hz produce effective parasympathetic modulation. We selected a mixed mode, using both low (2 Hz) and me |
| Control Group | Placebo comparator | Device: Transcutaneous auricular vagus nerve stimulationThe same device and electrodes used in the intervention group will be applied. No actual electrical current will be delivered. The session duration will be 30 minutes, with the same electrode placement and application positioning as the intervention group. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (0 listed)
Key exclusion criteria (7 listed)
- History of severe cardiac arrhythmias or recent electrical instability, including permanent atrial fibrillation, tachyarrhythmias, or the presence of an implantable cardioverter-defibrillator (ICD).
- Presence of a pacemaker or other implanted electronic devices.
- Severe neurological or psychiatric disorders, such as epilepsy, schizophrenia, or recent stroke (within the past 6 months).
- Active chronic inflammatory or autoimmune diseases that may interfere with inflammatory markers (e.g., systemic lupus erythematosus or rheumatoid arthritis).
- Acute infection or fever at the time of screening.
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 |
|---|---|---|
| Transcutaneous auricular vagus nerve stimulationTranscutaneous auricular vagus nerve stimulation (taVNS) will be performed daily for 30 minutes until hospital discharge. One electrode will be placed on the auricular concha to stimulate the auricular branch of the vagus nerve, and the other electrode will be positioned on the left earlobe to stimulate the great auricular nerve. The stimulation will be delivered using the EL-30 device (NKL Produtos Eletrônicos, Brusque, SC, Brazil), with a pulse width of 250 μs, intensity below the pain threshold, and alternating frequencies of 2 Hz for 5 seconds and 15 Hz for 5 seconds. The stimulation sites were selected based on auricular innervation, technical feasibility, and treatment standardization.The control group will use the same device; however, no active electrical current will be delivered (placebo stimulation). | Device | Control Group, Intervention Group |
Primary outcome
Heart rate variability (HRV) assessed before and after each stimulation session until hospital discharge
Time frame: Postoperative day 1 through hospital discharge. Stimulation will begin on postoperative day 1. HRV will be assessed immediately before and immediately after each daily stimulation session, from the first postoperative stimulation session until hospital
Heart rate variability (HRV) measured immediately before and immediately after each daily stimulation session until hospital discharge.
6 secondary outcomes
Quality of life assessed using the 36-Item Short Form Health Survey (SF-36).
Time frame: At hospital discharge following CABG.
Hospital complications (arrhythmias)
Time frame: From postoperative day 1 (POD 1) until hospital discharge.
Inflammatory Markers (C-Reactive Protein [CRP])
Time frame: From postoperative day 1 (POD 1) until hospital discharge, with daily measurements.
Pain Assessed Using the Visual Analog Scale (VAS)
Time frame: From postoperative day 1 (POD 1) until hospital discharge, with daily assessments.
Functional Capacity Assessed by the Six-Minute Walk Test (6MWT)
Time frame: At hospital discharge following coronary artery bypass grafting (CABG).
Hospital Length of Stay
Time frame: From the date of coronary artery bypass grafting (CABG) until hospital discharge.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Oct 2026.
- Background: PubMed 37194830Couceiro SM, Sant'Anna LB, Sant'Anna MB, Menezes RSM, Mesquita ET, Sant'Anna FM. Auricular Vagal Neuromodulation and its Application in Patients with Heart Failure and Reduced Ejection Fraction. Arq Bras Cardiol. 2023 May 15;120(5):e20220581. doi: 10.36660/abc.20220581. eCollection 2023. English, Portuguese.
- Background: PubMed 31078660Harris PA, Taylor R, Minor BL, Elliott V, Fernandez M, O'Neal L, McLeod L, Delacqua G, Delacqua F, Kirby J, Duda SN; REDCap Consortium. The REDCap consortium: Building an international community of software platform partners. J Biomed Inform. 2019 Jul;95:103208. doi: 10.1016/j.jbi.2019.103208. Epub 2019 May 9.
- Background21 DA SILVA, Roberto Léo et al. Avaliação da dor durante o cateterismo por via transradial utilizando Escala Visual Analógica. Revista Brasileira de Cardiologia Invasiva, v. 23, n. 3, p. 207- 210, 2015.
- Background20 Kubios HRV - Software de análise de variabilidade da frequência cardíaca Tarvainen MP , Niskanen J.PLipponen JA , Ranta-aho PO , Karjalainen PA (2014) Métodos e Programas de Computador em Biomedicina , 113 (1), pp.
- Background: PubMed 36560256Himariotis AT, Coffey KF, Noel SE, Cornell DJ. Validity of a Smartphone Application in Calculating Measures of Heart Rate Variability. Sensors (Basel). 2022 Dec 15;22(24):9883. doi: 10.3390/s22249883.
- Background: PubMed 37831376Yang J, Ben-Menachem E. Accuracy and clinical utility of heart rate variability derived from a wearable heart rate monitor in patients undergoing major abdominal surgery. J Clin Monit Comput. 2024 Apr;38(2):433-443. doi: 10.1007/s10877-023-01080-8. Epub 2023 Oct 13.
- Background: PubMed 22958960Thygesen K, Alpert JS, Jaffe AS, Simoons ML, Chaitman BR, White HD; Joint ESC/ACCF/AHA/WHF Task Force for Universal Definition of Myocardial Infarction; Authors/Task Force Members Chairpersons; Thygesen K, Alpert JS, White HD; Biomarker Subcommittee; Jaffe AS, Katus HA, Apple FS, Lindahl B, Morrow DA; ECG Subcommittee; Chaitman BR, Clemmensen PM, Johanson P, Hod H; Imaging Subcommittee; Underwood R, Bax JJ, Bonow JJ, Pinto F, Gibbons RJ; Classification Subcommittee; Fox KA, Atar D, Newby LK, Galvani M, Hamm CW; Intervention Subcommittee; Uretsky BF, Steg PG, Wijns W, Bassand JP, Menasche P, Ravkilde J; Trials & Registries Subcommittee; Ohman EM, Antman EM, Wallentin LC, Armstrong PW, Simoons ML; Trials & Registries Subcommittee; Januzzi JL, Nieminen MS, Gheorghiade M, Filippatos G; Trials & Registries Subcommittee; Luepker RV, Fortmann SP, Rosamond WD, Levy D, Wood D; Trials & Registries Subcommittee; Smith SC, Hu D, Lopez-Sendon JL, Robertson RM, Weaver D, Tendera M, Bove AA, Parkhomenko AN, Vasilieva EJ, Mendis S; ESC Committee for Practice Guidelines (CPG); Bax JJ, Baumgartner H, Ceconi C, Dean V, Deaton C, Fagard R, Funck-Brentano C, Hasdai D, Hoes A, Kirchhof P, Knuuti J, Kolh P, McDonagh T, Moulin C, Popescu BA, Reiner Z, Sechtem U, Sirnes PA, Tendera M, Torbicki A, Vahanian A, Windecker S; Document Reviewers; Morais J, Aguiar C, Almahmeed W, Arnar DO, Barili F, Bloch KD, Bolger AF, Botker HE, Bozkurt B, Bugiardini R, Cannon C, de Lemos J, Eberli FR, Escobar E, Hlatky M, James S, Kern KB, Moliterno DJ, Mueller C, Neskovic AN, Pieske BM, Schulman SP, Storey RF, Taubert KA, Vranckx P, Wagner DR. Third universal definition of myocardial infarction. J Am Coll Cardiol. 2012 Oct 16;60(16):1581-98. doi: 10.1016/j.jacc.2012.08.001. Epub 2012 Sep 5. No abstract available.
- Background: PubMed 23186602Prasad K, Sharma V, Lackore K, Jenkins SM, Prasad A, Sood A. Use of complementary therapies in cardiovascular disease. Am J Cardiol. 2013 Feb 1;111(3):339-45. doi: 10.1016/j.amjcard.2012.10.010. Epub 2012 Nov 24.
- Background: PubMed 35062542Pires IM, Denysyuk HV, Villasana MV, Sa J, Marques DL, Morgado JF, Albuquerque C, Zdravevski E. Development Technologies for the Monitoring of Six-Minute Walk Test: A Systematic Review. Sensors (Basel). 2022 Jan 12;22(2):581. doi: 10.3390/s22020581.
- Background14 Ciconelli, R M. Tradução para o português e validação do questionário genérico de avaliação de qualidade de vida "Medical Outcomes Study 36-Item Short- Form Health Survey (SF-36)". 1997. 148 p. Tese (Doutorado em Medicina) - Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, 1997.
- Background13 PSS Health. Cálculo do tamanho amostral. Medidas. Acesso em: 22/04/2025. Disponível em:<https://hcpa-unidade-bioestatistica.shinyapps.io/PSS_Health/>
- Background12 Villani, V., Tsagkaris, C., Dimitriadis, D., Zito, M., Anastasiou, A., & Giannopoulos, S. (2022). Effects of auricular vagus nerve stimulation on heart rate variability and autonomic balance. Autonomic Neuroscience, 240, 102964.
- Individual participant dataSharing planned: No
Related trials for Coronary Artery Bypass Grafting (CABG) Surgery
RecruitingObservational study
Prospective Study Protocol for Multiparametric PCCT Assessment of Early Ventricular Outcomes After CABG
Coronary Artery Bypass Grafting (CABG) Surgery, Coronary Artery Disease
Recruiting
ESPB vs SPSIP for Postoperative Analgesia After CABG
Coronary Arterial Disease, Coronary Artery Bypass Grafting (CABG) Surgery
Not yet recruitingPhase 2/3
Adductor Canal Block: Efficacy in Postoperative Pain Management for Cardiac Surgery
Coronary Artery Bypass Grafting (CABG) Surgery, Saphenectomy
Not yet recruiting
From Prehabilitation to Rehabilitation (Prehab2Rehab): Digitally Supported Short-Term Prehabilitation Prior to Cardiac Surgery
Coronary Artery Bypass Grafting (CABG) Surgery, Heart Valve Surgery
RecruitingPhase 2
Intravenous Fish Oil Based Lipid Emulsion to Enhance Recovery in High-Risk Cardiac Surgery Patients
Intensive Care Unit, Coronary Artery Bypass Grafting (CABG)
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. This study is not recruiting at the moment.
Ricardo Stein principal investigator
Hospital de Clínicas de Porto Alegre (HCPA)
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Transcutaneous auricular vagus nerve stimulation in people with Coronary Artery Bypass Grafting (CABG) Surgery and Vagus Nerve Stimulations, run by Hospital de Clinicas de Porto Alegre at 2 sites in Brazil.
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 0 inclusion and 7 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: finished, as of the sponsor's last update on 1 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Brazil. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Heart rate variability (HRV) assessed before and after each stimulation session until hospital discharge (time frame: Postoperative day 1 through hospital discharge. Stimulation will begin on postoperative day 1. HRV will be assessed immediately before and immediately after each daily stimulation session, from the first postoperative stimulation session until hospital). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07853222, which also lists 23 linked publications.
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 1 Oct 2026; AzTrials last refreshed its copy on 26 Oct 2026.