Right to Left Cardiac Shunt Detection

NCT01773252 | Terminated Phase 3

• 1 other identifier: FDS-0005
• Study Type: interventional
• Target: 141
• Locations: 1 country
• Sites: 8

Brief Summary

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").

Conditions

Right to Left Shunt; Patent Foramen Ovale; Atrial Septal Defect

Keywords

RLS; RTLS; PFO; ASD; shunt; cardiac; paradoxical thromboembolism; interventional cardiology; stroke; migraine; aura; obstructive sleep apnea; decompression illness; neurology; transesophageal echocardiography; TEE; transthoracic echocardiography; TTE; transcranial Doppler; ultrasound; TCD; power m Mode; indocyanine green dye; ICG; Valsalva

Outcome Measures

Primary Outcomes (2)

• Presence or absence of shunt

  To establish the sensitivity and specificity of the Cardiox FDS using transesophageal echocardiography (TEE) as the reference standard

  Five days

• Adverse Events

  To establish the safety of the Cardiox FDS device

  Five days

Secondary Outcomes (1)

• Presence or absence of shunt

  Three days

Study Arms (1)

TEE

EXPERIMENTAL

Within patient comparison of TEE, FDS and a TCD from select study sites

Device: Flow Detection System

Interventions

Flow Detection System DEVICE

Also known as: Model 100

TEE

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Cardiox Corporation: lead

Study Sites (8)

Heart and Vascular Center of Arizona

Phoenix, Arizona, 85006, United States

Location

UCLA Medical Center

Los Angeles, California, 90095, United States

Location

University of Colorado

Aurora, Colorado, 80045, United States

Location

Rush University Medical Center

Chicago, Illinois, 60612, United States

Location

Tufts Medical Center

Boston, Massachusetts, 02111, United States

Location

Columbia University Medical Center

New York, New York, 10032, United States

Location

Methodist DeBakey Heart and Vascular Center

Houston, Texas, 77030, United States

Location

Swedish Medical Center

Seattle, Washington, 98122, United States

Location

MeSH Terms

Conditions

Foramen Ovale, Patent; Heart Septal Defects, Atrial; Stroke; Migraine Disorders; Epilepsy; Sleep Apnea, Obstructive

Condition Hierarchy (Ancestors)

Heart Septal Defects; Heart Defects, Congenital; Cardiovascular Abnormalities; Cardiovascular Diseases; Heart Diseases; Congenital Abnormalities; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Headache Disorders, Primary; Headache Disorders; Sleep Apnea Syndromes; Apnea; Respiration Disorders; Respiratory Tract Diseases; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders

Study Officials

• Michael W Jopling, MD

  Cardiox Corporation

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NA
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 8, 2013
• First Posted: January 23, 2013
• Study Start: November 1, 2012
• Primary Completion: October 1, 2015
• Study Completion: November 1, 2015
• Last Updated: November 13, 2015

Record last verified: 2015-11

Locations

US (8)