T-wave Alternans and Intrathoracic Impedance Measurements

• Sponsor: Columbia University (Other)
• Overall Status: Completed
• CT.gov ID: NCT00669682
• Collaborator: Medtronic (Industry)
• Enrollment: 9
• Location: 1
• Duration (Months): 44
• Patients Per Site Per Month: 0.2

Study Details

Study Description

Brief Summary

T-wave alternans is a test that is currently being used to risk stratify patients with structural heart disease for sudden cardiac death. The mechanism of T-wave alternans is unclear, but may share a common abnormality with conditions of cardiac fluid overload such as heart failure, which is altered intracellular calcium handling. Current Medtronic implantable defibrillators have the capability of monitoring cardiac fluid status via transthoracic impedance measurements.

The purpose of this study is to determine if a correlation exists between T-wave alternans status and cardiac volume status, as determined by transthoracic impedance measurements. Secondarily, the study seeks to examine the relationship between arrhythmia frequency and T-wave alternans or cardiac volume status.

Condition or Disease	Intervention/Treatment	Phase
Congestive Heart Failure; Arrhythmias	Other: Congestive heart failure

Study Design

• Study Type: Observational
• Actual Enrollment: 9 participants
• Observational Model: Cohort
• Time Perspective: Prospective
• Official Title: T-wave Alternans and Intrathoracic Impedance Measurements
• Study Start Date: Aug 1, 2008
• Actual Primary Completion Date: Apr 1, 2012
• Actual Study Completion Date: Apr 1, 2012

Arms and Interventions

Arm	Intervention/Treatment
Group A The study group will include Class III to IV heart failure patients followed in the device clinic that have a chronically implanted (more than 90 days) Medtronic biventricular defibrillator with the ability to monitor intrathoracic impedance.	Other: Congestive heart failure; Spontaneous occurrence of fluid overload.

Outcome Measures

Primary Outcome Measures

1. Number of Positive Twave Studies and Concurrent Positive Optivol Measurement [upto 3 years]

   We wanted to examine whether positive Optivol status corresponded to a higher likelihood of a positive T wave study. The T wave alternans result is determined by a proprietary device that measures T wave and reports the result as negative, positive, or indeterminate. The Optivol measurement is obtained through transthoracic impedance values in the implanted device. We investigated the correlation between Optivol status and T wave alternans status.

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years and Older
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Inclusion Criteria:

• Class III or IV heart failure patients with a chronically implanted Medtronic biventricular defibrillator system capable of monitoring intrathoracic fluid volume.

Exclusion Criteria:

• no active ischemia or pulmonary edema, atrial fibrillation, complete heart block

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Columbia University Medical Center	New York	New York	United States	10032

Sponsors and Collaborators

• Columbia University
• Medtronic

Investigators

• Principal Investigator: Jose M Dizon, MD, Columbia University

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: Jose M. Dizon, Assoc Professor of Clinical, Department of Cardiology, Columbia University
• ClinicalTrials.gov Identifier: NCT00669682
• Other Study ID Numbers: AAAC5529
• First Posted: Apr 30, 2008
• Last Update Posted: Apr 19, 2013
• Last Verified: Apr 1, 2013

• Additional relevant MeSH terms: Heart Failure

Study Results

Participant Flow

Recruitment Details	9 patients enrolled from device clinic between 8/14/08 and 2/11/11

Arm/Group Title	Group A
Arm/Group Description	The study group will include Class III to IV heart failure patients followed in the device clinic that have a chronically implanted (more than 90 days) Medtronic biventricular defibrillator with the ability to monitor intrathoracic impedance.
Period Title: Overall Study
STARTED	9
COMPLETED	9
NOT COMPLETED	0

Baseline Characteristics

Arm/Group Title	Group A
Arm/Group Description	The study group will include Class III to IV heart failure patients followed in the device clinic that have a chronically implanted (more than 90 days) Medtronic biventricular defibrillator with the ability to monitor intrathoracic impedance.
Overall Participants	9
Age (Count of Participants)
<=18 years	0 0%
Between 18 and 65 years	7 77.8%
>=65 years	2 22.2%
Age (years) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [years]	60 (10)
Sex: Female, Male (Count of Participants)
Female	4 44.4%
Male	5 55.6%
Region of Enrollment (participants) [Number]
United States	9 100%

Outcome Measures

1. Primary Outcome

Title	Number of Positive Twave Studies and Concurrent Positive Optivol Measurement
Description	We wanted to examine whether positive Optivol status corresponded to a higher likelihood of a positive T wave study. The T wave alternans result is determined by a proprietary device that measures T wave and reports the result as negative, positive, or indeterminate. The Optivol measurement is obtained through transthoracic impedance values in the implanted device. We investigated the correlation between Optivol status and T wave alternans status.
Time Frame	upto 3 years

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Positive Optivol Status	Negative Optivol Status
Arm/Group Description	These patients have transthoracic impedance measurements that suggest fluid overload	These patients have transthoracic impedance measurements that do not suggest fluid overload
Measure Participants	3	6
Positive T wave alternans	1 11.1%	1 NaN
Negative T wave alternans	2 22.2%	5 NaN

Adverse Events

Arm/Group Title	Group A
Arm/Group Description	The study group will include Class III to IV heart failure patients followed in the device clinic that have a chronically implanted (more than 90 days) Medtronic biventricular defibrillator with the ability to monitor intrathoracic impedance.
All Cause Mortality
	Group A
	Affected / at Risk (%)	# Events
Total	/ (NaN)
Serious Adverse Events
	Group A
	Affected / at Risk (%)	# Events
Total	0/9 (0%)
Other (Not Including Serious) Adverse Events
	Group A
	Affected / at Risk (%)	# Events
Total	0/9 (0%)

Limitations/Caveats

[Not Specified]

More Information

Certain Agreements

Principal Investigators are NOT employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.