Tragus Stimulation to Prevent Atrial Fibrillation After Cardiac Surgery

Tragus Stimulation to Prevent Atrial Fibrillation After Cardiac Surgery: The TraP-AF Study

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT03392649

Acronym

TraP-AF

Enrollment

Registered

2018-01-08

Start date

2018-03-09

Completion date

2021-07-31

Last updated

2022-08-04

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Atrial Fibrillation

Keywords

Postoperative Atrial Fibrillation, Tragus Stimulation

Brief summary

Patients undergoing cardiac surgery, specifically a coronary artery bypass graft and/or heart valve replacement surgery, are at a higher risk for post-procedure atrial fibrillation (AF). AF is a condition in which the upper chambers of the heart do not contract normally and results in an irregular heartbeat. Recent studies have shown that tragus stimulation decreases the likelihood of AF in animals and humans. It has also been shown to reduce inflammation which may be related to post-procedure AF. Tragus stimulation involves stimulating a part of the outer ear, called the tragus, by sending a microcurrent through a small alligator clip. It is believed that tragus stimulation can affect the nervous system, which may reduce heart rate and lead to prevention of AF. The purpose of this study is to determine whether tragus stimulation in subjects undergoing cardiac surgery will lead to shorter occurrences, or even prevention, of AF.

Detailed description

This was a single-blind study where patients were randomized tragus stimulation versus sham procedure and remained blinded to their treatment allocation. Both treatment options utilized similar equipment, namely the use of alligator clips which will be placed on the tragus and earlobe of the right ear for patients. Prior to cardiac surgery, the discomfort threshold of both left and right tragus stimulation was determined for all participating patients. Intermittent electrode signals, or microcurrents, were delivered at 20 Hz with100 µsec pulse width with variable microampere (mA) output. The discomfort threshold was defined as the stimulation intensity in mA at which point patients experience discomfort. The stimulation intensity used in the study was set below the sensation and discomfort threshold. The clip was placed on the patient's ear at the end of surgery. Stimulation then continued, one ear alternating with the other, every 4 hours for a total of 48 hours. If the patient showed any sign of discomfort from stimulation, the intensity of stimulation was reduced to a level at which signs of discomfort disappears. Follow-up was performed with a 14-day event monitor at the time of discharge, as clinically indicated. Echocardiography were assessed prior to study initiation and when clinically available in follow-up.

Interventions

DEVICEParasym

Tragus stimulation was done using the Parasym device.

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

PREVENTION

Masking

SINGLE (Subject)

Eligibility

Sex/Gender

ALL

Age

18 Years to 89 Years

Healthy volunteers

Inclusion criteria

1. Patients ≥18 years of age, \<90 years of age 2. Estimated life expectancy of at least 1 year at the time of enrollment 3. History of sinus rhythm or paroxysmal atrial fibrillation

Exclusion criteria

1. Patients ≥90 years of age, \<18 years 2. Patients with known prior history of persistent or permanent AF 3. Atrial Fibrillation occurrence within the last 24 hours of procedure 4. Urgent or Emergency cases 5. Pregnant patients 6. Patients undergoing the following cardiac procedures: heart transplant, pulmonary thromboendarterectomy, isolated aortic arch procedures, congenital hear disease, ventricular assist device insertion, extracorporeal membrane oxygenation insertion, and surgical AF ablation 7. Antiarrhythmics prior to surgery (Class I and Class III) 8. High degree atrioventricular block requiring temporary pacing 9. Prior maze procedure for the treatment of AF

Design outcomes

Primary

Measure	Time frame	Description
Time to the First Episode of Atrial Fibrillation (AF) >30 Seconds	From end of surgery to end of hospitalization, up to 1 month.	Time to the first episode of atrial fibrillation (AF) that was greater than 30 seconds in patients who had AF. This was assessed on the review of patient chart and inpatient telemetry.
Number of Participants Hospitalized for >5 Days	From end of surgery to end of hospitalization, up to 1 month.	Number of participants with an overall length of hospitalization greater than five days.

Secondary

Measure	Time frame	Description
Number of Participants With Antiarrhythmic Used to Treat AF	From end of surgery to end of hospitalization, up to 1 month.	Number of participants that antiarrhythmic was use to treat atrial fibrillation (i.e., use of amiodarone)
Number of Participants With Inotropes Used for Blood Pressure Support During AF	From end of surgery to end of hospitalization, up to 1 month.	The number of participants who management of their postoperative atrial fibrillation (AF) required the use of inotropic vasoactive or pressor medications for blood pressure (BP) support
Overall Atrial Fibrillation (AF) Burden	From end of surgery to end of hospitalization, up to 1 month.	The total number of hours of atrial fibrillation (AF) burden as an inpatient.
All-cause Mortality	From end of surgery to end of hospitalization, up to 1 month.	Number of participants who suffered from mortality due to any cause during the inpatient period
Number of Participants With Stroke or Transient Ischemic Attack (TIA)	From end of surgery to end of hospitalization, up to 1 month.	The number of participants who suffered from a cerebral vascular accident (CVA) or transient ischemic attacks (TIA) for any cause during hospitalization was recorded.
Number of Participants With Rate Control Medications Used for AF	From end of surgery to end of hospitalization, up to 1 month.	Number of participants that the management of their postoperative atrial fibrillation (AF) utilized the use of rate-controlling medications such as beta-blockers, calcium-channel blockers, or the use of digoxin.

Countries

United States

Participant flow

Recruitment details

Subjects were recruited from the University of Chicago Medical Center

Participants by arm

Arm	Count
Stimulation Group At the end of cardiac surgery, the Parasym alligator clip was placed on the subject's tragus, and the subject received continuous stimulation for 48 hours. The clip was switched to the other ear every 4 hours. Parasym: Tragus stimulation was done using the Parasym device.	40
Sham Group At the end of cardiac surgery, the Parasym alligator clip was placed on the subject's tragus, but the Parasym was not turned on, and the subject did not receive any stimulation. The clip was switched to the other ear every 4 hours for a total of 48 hours.	41
Total	81

Baseline characteristics

Characteristic	Sham Group	Total	Stimulation Group
Age, Continuous	65.0 years	66.0 years	67.0 years
Aldosterone blockade	2 Participants	3 Participants	1 Participants
Angiotensin converting enzyme inhibition or receptor blockade	20 Participants	42 Participants	22 Participants
Beta-blocker	16 Participants	42 Participants	26 Participants
Body Mass Index	28.75 kg/m^2	28.56 kg/m^2	28.17 kg/m^2
Calcium channel blocker	11 Participants	24 Participants	13 Participants
Chronic kidney disease	6 Participants	18 Participants	12 Participants
Coronary artery bypass graft surgery (CABG)	17 Participants	42 Participants	25 Participants
Creatinine	0.9 micromoles/L	1.0 micromoles/L	1.1 micromoles/L
Diabetes Mellitus	11 Participants	25 Participants	14 Participants
Digoxin	1 Participants	1 Participants	0 Participants
End-stage renal disease	2 Participants	5 Participants	3 Participants
Height(cm)	177.8 cm	173 cm	172.7 cm
History of stroke or transient ischemic attack	4 Participants	10 Participants	6 Participants
Hypertension	29 Participants	61 Participants	32 Participants
NYHA Class Class I	1 Participants	1 Participants	0 Participants
NYHA Class Class II	14 Participants	24 Participants	10 Participants
NYHA Class Class III	15 Participants	36 Participants	21 Participants
NYHA Class No heart failure symptoms noted	11 Participants	20 Participants	9 Participants
Peripheral arterial disease	7 Participants	13 Participants	6 Participants
Race/Ethnicity, Customized Race African American	6 Participants	10 Participants	4 Participants
Race/Ethnicity, Customized Race Others	3 Participants	12 Participants	9 Participants
Race/Ethnicity, Customized Race White	32 Participants	59 Participants	27 Participants
Sex: Female, Male Female	7 Participants	19 Participants	12 Participants
Sex: Female, Male Male	34 Participants	62 Participants	28 Participants
Totally-endoscopic coronary artery bypass (TECAB)	5 Participants	9 Participants	4 Participants
Weight(kg)	92.3 kg	83.5 kg	79.4 kg

Adverse events

Event type	EG000 affected / at risk	EG001 affected / at risk
deaths Total, all-cause mortality	3 / 40	0 / 41
other Total, other adverse events	0 / 40	1 / 41
serious Total, serious adverse events	1 / 40	1 / 41