Imatron takes heart fromnew AHA study on CAD testing

Researchers find high sensitivity and specificity

Ultrafast CT manufacturer Imatron received some good news froma clinical study reported this month in Circulation, a journalpublished by the American Heart Association. The study found thatthe South San Francisco, CA, company's technology had a 95% sensitivityrate in detecting coronary calcifications in patients diagnosedwith coronary artery disease (CAD) by conventional angiography.News of the report prompted Imatron's stock to jump 25% to closeat $2.63 a share on March 1.

The study examined 710 patients at medical centers around theU.S. and was led by Dr. Bruce Brundage, chief of cardiology atHarbor-UCLA Medical Center in Torrance, CA. It is the first large-scalestudy of the use of Imatron's technology in detecting coronaryartery disease, according to the company.

Imatron hopes such studies will provide clinical support forthe use of ultrafast CT as a screening test for CAD. The studydid not examine the use of ultrafast CT as a screening test, however.

Despite the 95% sensitivity rate, the researchers found thatImatron's ultrafast CT had a specificity rating of only 44% instudies of patients with no significant coronary artery disease.The researchers said, however, that they were able to improvethe technology's specificity to 96% using probability tables thatfactored in the number of vessels involved with calcium depositsto predict the likelihood of a patient developing CAD.

The high specificity rating counters long-standing criticismof ultrafast CT that the technology is highly sensitive but notspecific, according to president and CEO Lewis Meyer.

"If you include the calcium score, plus the number ofarteries involved, a physician can predict the probability ofa patient having coronary artery disease," Meyer said.

While Imatron hopes the report will translate into higher salesof ultrafast CT scanners, the company expects the study to haveits greatest impact in validating its HeartScan imaging concept,Meyer said. HeartScan provides CAD screening directly to the public.

"Undoubtedly, it will translate into increased businessin our HeartScan subsidiary," Meyer said. "It removesa block in the cardiology community preventing widespread adoptionof this test."

Despite the good news, Imatron did have to conduct some damagecontrol in relation to the AHA's announcement of the study. Theassociation's press release describing the study's results claimedthat Imatron's ultrafast CT partner Siemens is planning to beginmanufacturing the scanners in the near future, a statement thatMeyer said was incorrect.

"There is no plan on the part of Siemens to manufactureultrafast CT scanners," Meyer said. "We make scannersfor Siemens to distribute. They have no plans to manufacture theirown systems."