Right to Left Cardiac Shunt Detection (PFO Detection)

November 10, 2015 updated by: Cardiox Corporation

A With-in Subject, Controlled Study to Determine the Sensitivity and Specificity of the Cardiox Flow Detection System for the Detection of Right-to-Left Cardiac Shunts Compared to Transesophageal Echocardiography and Transcranial Doppler Ultrasound

The purpose of this study is to evaluate the sensitivity and specificity of the Cardiox Flow Detection System (FDS) in identifying an intracardiac right-to-left shunt (RLS) compared to the results of transesophageal echocardiography (TEE).

RLS intracardiac shunts are associated with a number of clinically important syndromes including paradoxical thromboembolism (causing stroke or other systemic infarct), migraine headaches (particularly with aura), desaturation with obstructive sleep apnea, and decompression illness. From a research perspective, the detection of shunts in subjects with these types of syndromes is critical in helping to define the role of RLS in these disease processes. From a clinical perspective, shunt detection will be increasingly important in an era where interventional procedures for repairing cardiac defects are available for subjects determined to be at risk.

The currently accepted reference standard for detection of an intra-cardiac patent foramen ovale/atrial septal defect (PFO/ASD) RLS is a transesophageal echocardiography (TEE), a procedure that is invasive, uncomfortable, and requires conscious sedation.

Alternative options include transthoracic echocardiography (TTE) with injection of agitated saline (with and without Valsalva strain), a procedure that is far less sensitive than TEE due to the echocardiography imaging limitations seen in many adults.

Finally, transcranial Doppler (TCD) with injection of agitated saline (with and without Valsalva strain) is a newer entrant into this arena that does not require sedation or any invasive instrumentation.

The Cardiox Model 100 FDS utilizes an optical sensor positioned on the surface of the subject's skin at the scaphoid fossa of the ear. Next, a predetermined dose of an indicator dye, indocyanine green (ICG), is injected at a predetermined rate into a peripheral antecubital vein of the subject while the subject performs a breathing maneuver called a Valsalva maneuver. The exhalation by the subject into a mouthpiece connected to a pressure transducer via a flexible tubing extension, or its equivalent (ie, performing the Valsalva maneuver), is an essential step for all existing RLS detection methods. The Valsalva maneuver by the subject creates a pressure differential between the right and left sides of the heart. This Valsalva maneuver results in blood flow from the right side of the heart to the left side of the heart through an ASD, and/or causes a PFO, if present, to open, also allowing blood to flow directly from the right side to the left side of the heart without passing through the lungs (pulmonary vasculature) for oxygenation.

The Earpads, including their fluorescence sensor arrays (FSA), are used to measure the relative concentration (ie, fluorescence signal level) of ICG dye in the bloodstream as a function of time. If a premature inflection or peak occurs in the ICG dye concentration level at a time point prior to the rise and fall of the concentration associated with the main bolus of indicator, then a RLS is present in the heart. The amplitude of this premature ICG dye-dilution curve (referred to as "RLS-indicator dilution curve") is used to subsequently quantify the magnitude of the right-to-left shunt by ratiometrically comparing the amplitude of this RLS indicator dilution curve to the amplitude of the main indicator dilution curve associated with that portion of the injected ICG dye that follows the normal pathway from the right side of the heart, through the lungs, and into the left side of the heart (referred to as "normal indicator dilution curve").

Study Overview

Status

Terminated

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

141

Phase

  • Phase 3

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
    • Arizona
      • Phoenix, Arizona, United States, 85006
        • Heart and Vascular Center of Arizona
    • California
      • Los Angeles, California, United States, 90095
        • UCLA Medical Center
    • Colorado
      • Aurora, Colorado, United States, 80045
        • University of Colorado
    • Illinois
      • Chicago, Illinois, United States, 60612
        • Rush University Medical Center
    • Massachusetts
      • Boston, Massachusetts, United States, 02111
        • Tufts Medical Center
    • New York
      • New york, New York, United States, 10032
        • Columbia University Medical Center
    • Texas
      • Houston, Texas, United States, 77030
        • Methodist DeBakey Heart and Vascular Center
    • Washington
      • Seattle, Washington, United States, 98122
        • Swedish Medical 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:

  • At least 18 years of age;
  • Is currently scheduled (within five days of FDS) for a TEE study with agitated saline contrast (bubble study) or has had a TEE procedure with agitated saline contrast study (bubble study) within the previous 12 months;
  • If the Subject has undergone a shunt closure procedure, the protocol related TEE must be conducted greater than 12 months post closure.
  • Is able to read and understand the ICF and has voluntarily provided written informed consent;
  • Subject is able to perform a successful Valsalva maneuver (obtaining a score of 3 stars) using the Cardiox FDS device.

Exclusion Criteria:

  • Subjects with known allergy or sensitivity to ICG or to iodide contrast dye or iodides including medications with high iodine content;
  • Pregnant women or nursing mothers;
  • Subjects scheduled for a radioactive iodine uptake studies (eg, thyroid studies) within one week of completing this study.

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: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: TEE
Within patient comparison of TEE, FDS and a TCD from select study sites
Device: Flow Detection System
Other Names:
  • Model 100

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Presence or absence of shunt
Time Frame: Five days
To establish the sensitivity and specificity of the Cardiox FDS using transesophageal echocardiography (TEE) as the reference standard
Five days
Adverse Events
Time Frame: Five days
To establish the safety of the Cardiox FDS device
Five days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Presence or absence of shunt
Time Frame: Three days
To establish the positive percent agreement and the negative percent agreement of Cardiox FDS procedure with a transcranial Doppler (TCD) from select study sites.
Three days

Collaborators and Investigators

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

Sponsor

Cardiox Corporation

Investigators

  • Study Director: Michael W Jopling, MD, Cardiox Corporation

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

November 1, 2012

Primary Completion (Actual)

October 1, 2015

Study Completion (Actual)

November 1, 2015

Study Registration Dates

First Submitted

January 8, 2013

First Submitted That Met QC Criteria

January 18, 2013

First Posted (Estimate)

January 23, 2013

Study Record Updates

Last Update Posted (Estimate)

November 13, 2015

Last Update Submitted That Met QC Criteria

November 10, 2015

Last Verified

November 1, 2015

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • FDS-0005

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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