Resting MCE may prove superior to SPECT for identifying myocardial viability

Mar 6, 2004

NEW ORLEANS - Resting myocardial contrast echocardiography (MCE), a new bedside procedure that can determine microvascular perfusion, might one day replace ^99mTechnetium sestamibi SPECT for the diagnosis of myocardial viability following acute myocardial infarction, according to a poster presented today at the American College of Cardiology (ACC) meeting.

"The results showed similar sensitivity between contrast echocardiography and SPECT in predicting recovery of function following myocardial infarction. The specificity, however, of contrast (MCE) was quite a lot higher (78% versus 45%) than the specificity of SPECT," said lead author Dr. Michael Hickman from Northwick Park Hospital in London.

For this investigation, Hickman and his team enrolled 44 patients who underwent transthoracic echocardiography (TTE), resting contrast MCE, and nitrate-enhanced SPECT, seven to 10 days following the first acute myocardial infarction.

Researchers utilized a 16-segment model to assess opacification. All patients involved in the study went on to have revascularization. Within three to six months of revascularization, patients underwent TTE again to check for potential improvement.

"We found that contrast MCE was able to assess the myocardial blood flow more dynamically. It is able to reflect the temporal replenishment, whereas with SPECT you can only look at myocardial volume. Contrast MCE looks at blood flow while SPECT looks at volume. For this reason we hypothesized that myocardial contrast is superior to SPECT in assessing the future of recovery following myocardial infarction," Hickman said.

In addition, resting contrast MCE can be performed in a single breath-hold. "The implication is that using a resting contrast echocardiogram will enable clinicians to triage patients in terms of who should or who should not go on to revascularization," concluded Hickman.

By Jerry Ingram
AuntMinnie.com contributing writer
March 7, 2004

Myocardial ischemia, viability made apparent with MR, February 6, 2004

Cine MR cuts acute myocardial infarction exam time, April 3, 2003