Micro-bubble ultrasound contrast agents are a sterile suspension of Perflutren gas microspheres that are indicated for use in patients with suboptimal echocardiograms.
These products are used to opacify the left ventricular chamber and to improve the delineation of the left ventricular endocardial border.
Definity and Optison are the only micro-bubble products approved for use in the United States. FDA approved Optison in 1997. The manufacturer of Optison voluntarily temporarily suspended marketing the product in 2005. Definity has been marketed since FDA approval in 2001. Most postmarketing reports are associated with the use of Definity.
FDA ( Food and Drug Administration ) received postmarketing reports of 10 deaths following the administration of Definity and one death following Optison administration.
Most of the reported deaths were patients with severe underlying conditions and occurred one to 12 hours following administration of the contrast agent.
Some patients were also being treated with other medications that could have contributed to their death.
Four deaths, following cardiac arrest, occurred either during or within 30 minutes of the administration of Definity.
One patient received Definity and underwent a cardiac stress test while two patients had severe congestive heart failure and one patient was undergoing mechanical ventilation for respiratory failure.
FDA also received approximately 190 reports of serious non-fatal reactions following the administration of Definity and nine reports of serious non-fatal reactions following Optison administration.
Many of these reports describe the acute onset of symptoms suggestive of an anaphylactoid reaction including dyspnea or urticaria.
Other reports describe cardiopulmonary reactions with cardiac or respiratory arrest, loss of consciousness, convulsions, symptomatic arrhythmias ( atrial fibrillation, supraventricular tachycardia, ventricular tachycardia or fibrillation ), cardiac ischemia, hypotension, respiratory distress, and oxygen desaturation without signs or symptoms typical of an allergic reaction.
Many of these serious reactions occurred either during or within minutes of administration of the ultrasound contrast agent.
Source: FDA, 2007