Clinical trial NCT02661529: Enhancement of Contrast Opacification for Echocardiographic Imaging of the Right Heart and Shunts
Official title: Enhancement of Contrast Opacification for Echocardiographic Imaging of the Right Heart and Shunts
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Bidirectional Cardiovascular Shunt
Keywords: Shunt
Echocardiogram
Lead sponsor: Mayo Clinic
Sponsor class: OTHER
First posted: 2016-01-22
Enrollment: 100
Sex: ALL
Minimum age (years): 18
Maximum age (years): 105
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: DIAGNOSTIC

Brief summary: The study aims to answer whether the use of a mixture of blood and saline alone (limited air) provides the same degree of right-heart contrast enhancement as compared to the standard agitated saline (with air), during two types of echocardiograms.

Detailed description: A cardiovascular shunt is an abnormality of the blood flow between the sides of the heart or between the systemic and pulmonary circulation. A right-to-left shunt diverts blood from the right side of the heart to the left side or from the pulmonary to the systemic circulation through an anomalous opening such as septal defect or patent ductus arteriosus. To visualize the shunt during an echocardiogram, agitated saline solution is injected intravenously to provide air microbubble contrast which opacifies (makes visible) the right heart chambers and is the standard used for the non-invasive detection of right to left intracardiac or intrapulmonary shunts. However, agitated saline has the potential risk of air microembolism. Although this type of adverse event is uncommon (\<1% of strokes are related to air embolism), there have been reports in the literature of a number of small strokes/transient ischemic attacks following agitated saline injections at the time of echocardiographic studies. Mixing blood with saline substantially reduces the amount of air introduced, and this study will attempt to quantify the differences in the degree of contrast enhancement.

100 patients scheduled for either Transesophageal Echocardiogram (TEE) or Transthoracic Echocardiogram (TTE) will be studied to determine the degree of contrast enhancement, when using a Saline/Air mixture versus a Saline/Blood mixture. Fifty participants of each type of echocardiography will be studied. The standard agitated saline mixture consists of 10 milliliters of sterile saline and 0.5 milliliters of air agitated together in a syringe prior to injection. The agitated Saline/Blood mixture consists of 9 milliliters of sterile saline and 0.5 - 1 milliliter of blood and agitated together in a syringe prior to injection.

All study participants will complete the routine clinical echocardiography (either a TEE or a TTE) with peripheral injection of agitated Saline/Air mixture, via an intravenous (IV) cannula attached to a three way stop cock. Blood removed from the patient will be withdrawn through the IV into a syringe and agitated with saline and then re-injected into the patient through the same tubing. After completion of the standard clinical imaging for shunt, the Saline/Blood mixture will be infused and an image obtained for comparison.

For each study, digital images will be stored and an Investigator who does not know which treatment arm/mixture was used for a given image, will subsequently rate image quality and assign an image score using a semi-quantitative scale: 0 = poor/no right atrial opacification, 1 = average right atrial opacification, 2 = good right atrial opacification. After all images are analyzed, the scores will be compared for both TEE and TTE studies.

Eligibility criteria: Inclusion Criteria

* Subjects having clinically indicated transesophageal or transthoracic echocardiogram, as ordered by their physician to detect a shunt.

Exclusion Criteria

* Unwillingness to provide consent to participate in the study

Primary outcomes:
measure: Degree of right atrial opacification on echocardiogram image
timeFrame: Day 1
Secondary outcomes:
Other outcomes:
Locations:
city: Rochester
country: United States
facility: Mayo Clinic in Rochester
state: Minnesota
Study officials:
affiliation: Mayo Clinic
name: Garvan Kane, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Ali MA, Hepinstall MJ, Cassidy CS, Lane CM, Pellikka PA, Thaden JJ, Pislaru SV, Kane GC. Agitated Blood-Saline Rather Than Agitated Air-Saline for Echocardiographic Shunt Studies. J Am Soc Echocardiogr. 2020 Aug;33(8):1032-1033. doi: 10.1016/j.echo.2020.03.014. Epub 2020 Jun 10. No abstract available.