Trial Outcomes & Findings for The Effect of an Azygos Vein Coil on Defibrillation Threshold (NCT NCT00798174)

NCT ID: NCT00798174

Last Updated: 2018-09-28

Results Overview

Defibrillation threshold will be estimated by repeat defibrillation testing using an azygos coil and using an SVC coil (and compared). The outcome measure quoted below is the mean DFT using the azygos coil vs. the mean DFT using the standard configuration.

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 32 participants
• Primary outcome timeframe: During the course of the implant procedure and testing
• Results posted on: 2018-09-28

Participant Flow

Patients undergoing Implantable Cardioverter-Defibrillator (ICD) implantation in the electrophysiology laboratory were recruited. Both outpatients (recruited from the electrophysiology clinic) and inpatients (recruited from Barnes-Jewish Hospital) were included.

Participant milestones

Measure	Standard Configuration First 1. st time period (approx. 0.5 hour): Defibrillation Threshold (DFT) testing was performed with standard configuration first. A maximum of three inductions of ventricular fibrillation (VF) with defibrillation were performed to establish a standard configuration threshold. There were at least 5 minutes between defibrillation tests, so the standard configuration period was approximately 0.5 hour. 2. nd time period: The azygos coil was then added for the second phase. (Azygos vein coil: Addition of an azygos vein defibrillation coil in place of a standard superior vena cava (SVC) coil.)	Azygos Coil Configuration First 1. st time period (approx 0.5 hr): DFT testing was performed with an azygos coil in place first. A maximum of three inductions of VF with defibrillation were performed to establish a standard configuration threshold. There were at least 5 minutes between defibrillation tests, so the standard configuration period was approximately 0.5 hour. 2. nd time period (approx 0.5 hour): The azygos coil was then excluded from the shocking configuration and replaced by the standard SVC coil configuration for the second phase.
Overall Study STARTED	16	16
Overall Study COMPLETED	12	13
Overall Study NOT COMPLETED	4	3

Reasons for withdrawal

Measure	Standard Configuration First 1. st time period (approx. 0.5 hour): Defibrillation Threshold (DFT) testing was performed with standard configuration first. A maximum of three inductions of ventricular fibrillation (VF) with defibrillation were performed to establish a standard configuration threshold. There were at least 5 minutes between defibrillation tests, so the standard configuration period was approximately 0.5 hour. 2. nd time period: The azygos coil was then added for the second phase. (Azygos vein coil: Addition of an azygos vein defibrillation coil in place of a standard superior vena cava (SVC) coil.)	Azygos Coil Configuration First 1. st time period (approx 0.5 hr): DFT testing was performed with an azygos coil in place first. A maximum of three inductions of VF with defibrillation were performed to establish a standard configuration threshold. There were at least 5 minutes between defibrillation tests, so the standard configuration period was approximately 0.5 hour. 2. nd time period (approx 0.5 hour): The azygos coil was then excluded from the shocking configuration and replaced by the standard SVC coil configuration for the second phase.
Overall Study inability to implant azygos coil	3	3
Overall Study Inability to sedate for DFT testing	1	0

Baseline Characteristics

The Effect of an Azygos Vein Coil on Defibrillation Threshold

Baseline characteristics by cohort

Measure	Standard SVC Coil vs. Azygos Coil n=25 Participants The DFT with the standard SVC coil vs. DFT with the azygos vein coil in place. Azygos vein coil: Addition of an azygos vein defibrillation coil instead of a standard SVC coil.
Age, Categorical <=18 years	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	19 Participants n=5 Participants
Age, Categorical >=65 years	6 Participants n=5 Participants
Sex: Female, Male Female	7 Participants n=5 Participants
Sex: Female, Male Male	18 Participants n=5 Participants
Region of Enrollment United States	25 participants n=5 Participants

PRIMARY outcome

Timeframe: During the course of the implant procedure and testing

Population: All enrolled patient who were able to undergo azygos coil implant and defibrillation testing.

Defibrillation threshold will be estimated by repeat defibrillation testing using an azygos coil and using an SVC coil (and compared).

The outcome measure quoted below is the mean DFT using the azygos coil vs. the mean DFT using the standard configuration.

Outcome measures

Measure	Standard Configuration vs. Azygos Coil n=25 Participants The DFT with the standard SVC coil vs. DFT with the azygos coil. In this crossover study, each patient serves and own control, with defibrillation testing performed with and with the azygos coil Standard configuration vs. azygos coil: Addition of an azygos vein defibrillation coil instead of a standard SVC coil.
Difference in the DFT With an Azygos Vein Coil Versus the Standard SVC Coil. DFT wtih Azygos coil	10.4 Joules Standard Deviation 7.7
Difference in the DFT With an Azygos Vein Coil Versus the Standard SVC Coil. DFT with Standard Configuration	12.2 Joules Standard Deviation 8.61

Adverse Events

Standard Configuration vs. Azygos Coil Configuation

Serious events: 0 serious events

Other events: 1 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Measure

Standard Configuration vs. Azygos Coil Configuation n=25 participants at risk The DFT with the standard SVC coil vs. DFT with the azygos vein coil in place. Since all subjects underwent attempted azygos vein implantation, the implantation procedure was the same for the arm in which the standard configuration was tested first and the arm in which the azygos configuration was tested. first. Therefore, the two arms (Standard configuration tested first and Azygos configuration tested first) were combined for the purpose of adverse events.

Blood and lymphatic system disorders Loss of intergrity of Lead introducer

4.0% 1/25 • Number of events 1 • 24 hours Definitions are as the clinicaltrials.gov definitions. Patients were follow for clinically for 24 hours after their implant and defibrillation testing procedure.

Additional Information

Dr. Timothy W. Smith

Washington University in St. Louis

Phone: 314-286-1501

Email: tsmith@wustl.edu

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place