Safety of Ultrasound Contrast Agents in Patients With Known or Suspected Cardiac Shunts

Rush University Medical Center, Chicago, Illinois.
The American journal of cardiology (Impact Factor: 3.28). 06/2013; 112(7). DOI: 10.1016/j.amjcard.2013.05.042
Source: PubMed


Contrast-enhanced ultrasound imaging is a radiation-free diagnostic tool that uses biocompatible ultrasound contrast agents (UCAs) to improve image clarity. UCAs, which do not contain dye, often salvage "technically difficult" ultrasound scans, increasing the accuracy and reliability of a front-line ultrasound diagnosis, reducing unnecessary downstream testing, lowering overall health care costs, changing therapy, and improving patient care. Two UCAs currently are approved and regulated by the US Food and Drug Administration. They have favorable safety profiles and risk/benefit ratios in adult and pediatric populations, including compromised patients with severe cardiovascular diseases. Nevertheless, these UCAs are contraindicated in patients with known or suspected right-to-left, bidirectional, or transient right-to-left cardiac shunts. These patients, who constitute 10% to 35% of the general population, typically receive no UCAs when they undergo echocardiography. If their echocardiographic images are suboptimal, they may receive inappropriate diagnosis and treatment, or they may be referred for additional diagnostic testing, including radiation-based procedures that increase their lifetime risk for cancer or procedures that use contrast agents containing dye, which may increase the risk for kidney damage. An exhaustive review of current peer-reviewed research demonstrated no scientific basis for the UCA contraindication in patients with known or suspected cardiac shunts. Initial safety concerns were based on limited rodent data and speculation related to macroaggregated albumin microspheres, a radioactive nuclear imaging agent with different physical and chemical properties and no relation to UCAs. Radioactive macroaggregated albumin is not contraindicated in adult or pediatric patients with cardiac shunts and is routinely used in these populations. In conclusion, the International Contrast Ultrasound Society Board recommends removal of the contraindication to further the public interest in safe, reliable, radiation-free diagnostic imaging options for patients with known or suspected cardiac shunts and to reduce their need for unnecessary downstream testing.

Download full-text


Available from: Paul A Grayburn, Oct 28, 2014
  • [Show abstract] [Hide abstract]
    ABSTRACT: Contrast echocardiography is an established imaging method and an essential tool in every state of the art echocardiographic laboratory. It has also been the subject of several major clinical and research studies during the last year. This article addresses the impact of these studies on the clinical use of contrast echocardiography. Most recent studies have been performed with commercially available ultrasound contrast agents, which cross the pulmonary vasculature and are used for assessment of the left heart. The principle licensed indication for these contrast media is the delineation of left ventricular (LV) borders, masses, and aneurysms. The superiority of 2-dimensional contrast echocardiography over nonenhanced 2-dimensional imaging has been confirmed for assessment of LV volumes and ejection fraction, and there is growing evidence for the use of contrast 3-dimensional echocardiography. Two studies have demonstrated the usefulness of contrast-enhanced TEE for detection of thrombi in the left atrial appendage. The improved endocardial definition seen with ultrasound contrast media can also be used for strain analysis on selected systems. In stress echocardiography, contrast has been used for myocardial perfusion imaging in addition to assessment of regional LV wall motion. A large European multicenter study has demonstrated Sonovue-enhanced myocardial contrast echocardiography to be more sensitive than nuclear single photon emission computed tomography (SPECT) for the detection of significant coronary artery disease. Two further studies are discussed, which have demonstrated the impact of isolated perfusion defects on patients’ outcome. In addition, several publications have supplemented existing evidence regarding the safety of commercially available contrast agents. Recent studies continue to establish the usefulness and safety of contrast echocardiography for the currently licensed indications. There is also now good evidence for the use of myocardial contrast echocardiography as an alternative to nuclear imaging.
    No preview · Article · Dec 2013 · Current Cardiovascular Imaging Reports
  • Source

    Full-text · Article · Feb 2014 · JACC. Cardiovascular imaging
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Intrapulmonary arteriovenous anastomoses (IPAVs) are large-diameter pathways that directly connect the arterial and venous networks, bypassing the pulmonary capillaries. Ubiquitously present in healthy humans, these pathways are recruited in experimental conditions by exercise, hypoxia, and catecholamines and have been previously shown to be closed by hyperoxia. Whether they play a role in pulmonary pathophysiology is unknown. Here, we describe IPAV recruitment associated with hypoxemia and right-to-left shunt in a patient with status asthmaticus, treated with agonists of the B2-adrenergic pathway. Our observation of IPAVs in a pediatric patient, mechanically ventilated with 100% O2, suggests that these pathways are recruited in clinically important circumstances and challenges the notion that IPAVs are always closed by alveolar hyperoxia.
    Preview · Article · Mar 2014 · PEDIATRICS
Show more