Imatron defends coronary CT turf from mechanical scanner developers

May 12, 1999

Firm argues EBCT still best for cardiac scoringUltrafast CT manufacturer Imatron has spent years convincing the radiology community that its technology can be a clinically useful tool for predicting the likelihood of heart attacks in asymptomatic

Firm argues EBCT still best for cardiac scoring

Ultrafast CT manufacturer Imatron has spent years convincing the radiology community that its technology can be a clinically useful tool for predicting the likelihood of heart attacks in asymptomatic patients. Imagine the South San Francisco, CA, company’s frustration, then, as conventional CT developers begin to encroach on its turf, just when CT coronary artery studies are beginning to win clinical acceptance.

In a news conference held April 28, Imatron executives launched a spirited defense of the company’s coronary CT franchise. The company refuted a recent study claiming that mechanical CT scanners outfitted with ECG gating could perform coronary artery calcification studies just as well as Imatron’s electron beam-based systems. This finding is important, as clinicians are beginning to recognize the presence of calcification in the coronaries as a sign that a patient could develop heart disease in the future.

The study in question was conducted by researchers at Wake Forest University in Winston-Salem, NC, and was presented in March at the American Heart Association’s conference on cardiovascular disease epidemiology and prevention in New Orleans. Wake Forest researchers argued that standard single-slice mechanical CT scanners—specifically spiral CT units with ECG gating—could prove as effective as electron-beam scanners for acquiring coronary artery calcification scores.

The researchers scanned 33 patients with GE Medical Systems’ HiSpeed CT/i scanner and SmartScore coronary artery calcification package, then scanned them with Imatron’s ultrafast CT. The researchers argued that not only are the two technologies comparable, but the cardiac CT packages could be clinically viable on the installed base of 10,000 CT scanners in the U.S. The Wake Forest study received widespread attention in the consumer media, including articles in the Associated Press and The New York Times.

How does the Wake Forest study affect Imatron’s market prospects? It doesn’t, according to Imatron president and CEO Lewis Meyer. During the April 28 news conference, Meyer criticized the study for shortcomings such as a small sample size and the use of patients who already had significant symptoms of coronary artery disease. He reemphasized the reasons EBCT remains the gold standard for calcium scoring.

“The conclusion is that since (mechanical CT) can detect coronary calcium in that sample, this justifies that (calcium scoring packages) would be useful and retrofittable on the 10,000 conventional CT scanners installed in the U.S.,” he said. “We couldn’t disagree more. All of the luminary cardiology experts disagree with the conclusion that this test is to find really sick people. The people we want to find are the people who have atherosclerosis and don’t know it.”

Meyer also emphasized that the conventional CT scanning process used in the study was based on retrospective gating, a technique that images the heart continuously, rather than during its resting phase. Not only does this technique mean patients are exposed to more radiation, it means clinicians must select images out of the batch that were taken when the heart was at rest, which can mean more opportunity for error, Meyer said.

Yet other multimodality vendors aren’t so sure the Wake Forest study and others like it won’t affect the viability of Imatron’s market niche. For some, the study’s ramifications are clear: If traditional CT scanners can produce scoring results comparable to electron-beam scanners, hospitals may choose to upgrade existing CT systems to gain CAC capacity, rather than shelling out almost $2 million for a system dedicated solely to coronary artery calcification scoring.

“The difference (between standard CT and EBCT) is the cost,” said Sabine Duffy, marketing manager for CT at Siemens Medical Systems in Iselin, NJ. “Conventional CT is far less expensive, and hospitals can use it to image other body regions: brain, chest, abdomen, peripherals. So you have a multi-use scanner that can also do cardiac. With EBCT, it’s focused on cardiac. There aren’t too many hospitals that can survive solely on (scanning) cardiac patients.”

The fact that the Wake Forest study included a GE product further confused industry watchers and Imatron shareholders. Imatron and GE signed an agreement last June in which Imatron gave GE distribution rights for Imatron’s electron-beam unit (SCAN 6/24/98). GE’s cardiology sales team markets the scanner, and therein lies the potential conflict between Imatron’s ultrafast CT operations and GE’s future developments on the cardiac CT front. GE executives were unavailable for comment on the Wake Forest study, but in the conference call Meyer admitted that his company has yet to see as big a payoff from the GE relationship as it originally estimated.

“Were we overly optimistic about the relationship (with GE)? No question,” Meyer said. “The GE cardiology sales force is relatively green, and the unfortunate and unavoidable part is that the buying cycle time related to an Imatron EBCT is roughly a year, rarely less than six months. And a $1.75 million purchase is not something hospitals enter into lightly.”

© 1999 Miller Freeman, Inc.All rights reserved.