Doctors at Mercy Hospital in Coon Rapids have been among the first in the nation to use a new technology that combines blood flow measurements in coronary arteries with infrared scanning to better find and then clear blockages to the heart.

Called the Ilumien PCI Optimization System and made by St. Jude Medical Inc., the technology is helping Dr. Jeff Chambers make better decisions on what blockages pose the greater risk to patients. That, in turn, makes treatment more efficient, he said.

"Ilumien puts both technologies on the same machine and the same platform. I can use one or the other," said Chambers, an interventional cardiologist and director of the catheterization lab at the Metropolitan Heart & Vascular Institute at Mercy. "It makes it much easier for me to tell if a lesion is severe and needs treatment."

Ilumien pairs what is called fractional flow reserve (FFR), which measures pressure in an artery to find possible blockages, with infrared imaging called optical coherence tomography (OCT). The imaging technology is like a "high-definition television" compared with traditional ultrasound imaging that he has used for years, Chambers said. He is among the first physicians in the country to use Ilumien, which was approved by the U.S. Food and Drug Administration several months ago.

"You can really see the structures better," Chambers said.

Coronary artery disease is the most common type of heart disease, affecting millions of people worldwide. It is caused by a narrowing or blocking of the arteries from plaque, which restricts blood flow and reduces the amount of oxygen to the heart.

Doctors use several tools to treat the disease, including an X-ray examination of the blood vessels of the heart and FFR. Doctors then use that information to guide treatment, often using balloon angioplasty to open the blockage and placing a stent to inhibit blockages from reoccurring.

Last week, St. Jude Medical released study results showing that patients who received blood-flow measurements in the coronary arteries to guide the placement of stents were significantly less likely to be readmitted to the hospital.

The Ilumien system combines those blood flow measurements with scanning that lets doctors actually see inside the blood vessel and measure the size of the blockage to better guide stent selection and placement. The OCT also helps doctors see if the procedure was successful.

"You can tell how severe it is, you can tell the composition of the blockage, whether it is soft plaque or hard," Chambers said. "And you can measure the size of the vessel you are treating so you know what size balloons or stents to use."

He added: "The ultimate goal is to make people feel better, and we always want to use the best tools for the job."

Chambers, who is using the new technology daily at Mercy, said he has no financial relationship with St. Jude. The technology also is available at Abbott Northwestern Hospital in Minneapolis and at United Hospital in St. Paul.

Ilumien is another opportunity for Little Canada-based St. Jude to continue building its business in the area of technology that treats heart disease. Senior analyst Larry Biegelsen of Wells Fargo & Co. last week said in a letter to investors that he projects St. Jude's sales of FFR technology for 2012 to hit $138 million, up 28 percent, and to grow to $298 million in 2016.

A spokeswoman for St. Jude on Wednesday said the company estimates that it has converted more than 15 percent of the global market for intravascular ultrasound to the new OCT technology. The company has a leading share of the FFR market "based on our pioneering position, our strong pipeline of next-generation products and our sponsorship of multiple landmark clinical trials," said spokeswoman Amy Jo Meyer.

Frank Callaghan, president of St. Jude's cardiovascular and ablation technologies division, said at a recent analyst meeting that the estimated market potential for FFR, OCT and intravascular ultrasound is $2.1 billion.

James Walsh • 612-673-7428