Evaluating Myocardial Injury for Defibrillation Threshold Testing Methods for ICD Implantation (ULV)

May 20, 2019 updated by: Ulrika Birgersdotter-Green, University of California, San Diego

Evaluating Myocardial Injury During ICD Implantation Using the Upper Limit of Vulnerability (ULV) Method vs. Standard Defibrillation Threshold Testing

The objective of this study is to evaluate myocardial injury, if any, as quantified by cardiac markers (Troponin-T) in defibrillation threshold (DFT) testing during implantation of implantable cardioverter defibrillators (ICDs) using the upper limit of vulnerability (ULV) method vs. standard defibrillation threshold method.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

This is a prospective, randomized (1:1 DFT vs ULV testing), controlled clinical research trial. Patients undergoing ICD implant or device change out will be candidates for this study. Medical records for these patients will be screened prior to enrollment to ensure eligibility for the study. Each patient who is a candidate and who agrees to participate in the study will undergo the standard of care pre-procedure evaluation including a complete medical history evaluation, a complete physical examination and routine laboratory testing including chemistry panel, hematology panel, coagulation panel, a 12-lead electrocardiogram, and a urine pregnancy test (all females of child-bearing age). A candidate patient will be randomly assigned to either the standard DFT testing method group or the ULV testing method group.

For the standard DFT testing group, per routine standard of care, the patient will be admitted to the hospital. The study requires a pre-procedure blood test of 3 ml for Troponin-T (TnT) which will be drawn prior to any DFT testing. The blood sample will be sent to the University of California, San Diego (UCSD) central laboratory for processing. The patient will then undergo the scheduled ICD implant procedure in a standard fashion. The standard defibrillation threshold testing will be performed using a low energy shock delivered on T-wave to induce ventricular fibrillation (VF). If VF is induced, the first shock is 25 Joules (J). If success, we will wait 5 minutes and repeat the process. If the 2nd shock yields success, the DFT testing is complete and a 10J safety margin achieved (device shock energy is set at 35J or as clinically indicated determined by treating Cardiac Electrophysiologist). A back-up external defibrillator will always be immediately available in case transvenous shocks fail. Blood pressure will be monitored before and immediately after each shock. After 4 hours, 8 hours and 16 hours post DFT testing, blood samples (3 ml for Troponin-T) will be drawn and sent to the UCSD central laboratory for processing.

For the ULV testing group, per routine standard of care, the patient will be admitted to the hospital. The study requires a pre-procedure blood test (3 ml for Troponin-T.) which will be drawn prior to any ULV testing. The blood sample will be sent to the UCSD central laboratory for processing. The patient will then undergo the scheduled ICD implant procedure as is standard clinical care. The ULV testing is performed as follows: for single coil device, a 18J shock will be delivered at 0msec, +20 msec, -20msec and -40msec measured from the peak of the T-wave; for dual coil device, a 18J shock will be delivered at 0msec, -20msec, +20msec, and +40msec measured from the peak of the T-wave. If VF is not induced with any of the above mentioned shocks, the ULV will be considered as 18J and the ICD will be implanted with the first shock strength set at 30 joules or as clinically indicated determined by treating Cardiac Electrophysiologist. If VF is induced, a 25J rescue shock will be delivered as is standard and if successful, the device will be programmed to the maximum output of 35 joules or as clinically indicated determined by treating Cardiac Electrophysiologist. Blood pressure will be monitored before and immediately after each shock. After 4 hours, 8 hours and 16 hours post ULV testing, blood samples (3 ml for Troponin-T) will be drawn and sent to the UCSD central laboratory for processing.

Other than the blood tests for Troponin-T, there is no change in routine post-operative management. Patients will be followed every three months, as is standard management for patients with ICDs.

The TnT blood draws at 4-hour, 8-hour and 16-hour post implantation will not require longer hospital stay than is standard for patients undergoing ICD implantation. The results of Troponin-T measurement for the study patients will be reviewed by the cardiac electrophysiology (EP) research staff. If myocardial injury is noted (any TnT value >0.1 as per current assay at the UCSD laboratory), the patient will be monitored as is deemed clinically necessary by treating Cardiac Electrophysiologist, including possible repeat TnT measurements for evaluation of myocardial infarction. We will follow standard of care for management of myocardial injury as recommended by the American Heart Association and the American College of Cardiology. Elevated TnT measurements may delay hospitalization, if determined to be clinically necessary. If the repeat TnT measurement is <0.1, then myocardial injury is most unlikely and the positive TnT value is likely due to DFT shocks.

Study Type

Interventional

Enrollment (Actual)

60

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • La Jolla, California, United States, 92093
        • UCSD Sulpizio Cardiovascular Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Patients eligible to receive an ICD implant or change out.
  • Patients with a single or dual coil right ventricle (RV) defibrillation lead located in the RV apex.
  • Patients greater than 18 years of age.
  • Patients willing and able to give informed consent.
  • Patients who have insurance which may cover additional hospital stay if myocardial injury resulted from testing

Exclusion Criteria:

  • Patients with medical conditions that would limit study participation.
  • Patients that are pregnant

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Standard Defibrillation Testing
Standard Defibrillation Threshold Testing is a procedure in which a low energy shock will be delivered to the heart to induce ventricular fibrillation (VF) followed by a rescue shock to restore sinus rhythm. Process is repeated after 5 minutes.
Device: Standard Defibrillation Testing
Once the ICD is implanted, Standard Defibrillation Threshold (DFT) testing will begin. A low energy shock will be delivered to the heart at the peak of the T wave to induce ventricular fibrillation (VF). Once VF is induced, a rescue shock of 25J will be delivered to restore sinus rhythm. This process will be repeated once more after 5 minutes.
Other Names:
  • ICD implantation
Active Comparator: Upper Limit of VulnerabilityTesting
Upper Limit of Vulnerability Testing is a procedure in which four 18J shocks will be delivered at specified intervals. If VF is induced, then a 25 J rescue shock will be delivered.
Device: Upper Limit of Vulnerability Testing
Once the ICD is implanted, Upper Limit of Vulnerability (ULV) testing will commence. An 18 J shock will be delivered will at different points from the t-wave. If VF is not induced with any of these shocks, then the ULV will be considered to be 18J. If VF is induced, then a 25 J rescue shock will be delivered.
Other Names:
  • ICD implantation

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Myocardial Damage
Time Frame: 20 hours (hr)
Myocardial damage will be evaluated by cardiac troponin (cTNT) lab collection before and then after ULV or DFT testing at 4 hours, 8 hours, and 20 hours.
20 hours (hr)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Defibrillation Testings (DFT) vs. Upper Limit of Vulnerability (ULV) (VF Induced)
Time Frame: 20 hours (hr)
the DFT group cardiac troponin (cTNT) values were compared to the subjects within the ULV group that required VF induction.
20 hours (hr)
Defibrillation Testing (DFT) Versus Upper Limit of Vulnerability (ULV) (Non-induced)
Time Frame: 20 hours (hr)
The DFT group was compared to the ULV subgroup that did not require ventricular fibrillation (VF) induction. Cardiac troponin (cTNT) levels were analyzed.
20 hours (hr)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of California, San Diego

Collaborators

Medtronic

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

August 1, 2011

Primary Completion (Actual)

April 1, 2015

Study Completion (Actual)

June 1, 2015

Study Registration Dates

First Submitted

April 9, 2014

First Submitted That Met QC Criteria

April 9, 2014

First Posted (Estimate)

April 11, 2014

Study Record Updates

Last Update Posted (Actual)

May 22, 2019

Last Update Submitted That Met QC Criteria

May 20, 2019

Last Verified

May 1, 2019

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 110647

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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