InfraReDx (Burlington, Massachusetts) is aiming at developing its technology to provide pictures of coronary arteries using its Near Infrared spectroscopic system, a system that received FDA 510(k) clearance in June.

However, the company just announced the clearance last week, prior to its appearance this week at the Transcatheter Cardiovascular Therapeutics meeting in Washington.

InfraReDx wants to take that system one step farther toward a 510(k) clearance for use in detecting lipid-rich plaques, or those that are referred to as vulnerable plaques and thought to break away from artery walls and stop blood flow in the heart, thus causing heart attacks.

"This clearance represents a major milestone in our efforts to provide a tool for the assessment of coronary artery disease," said James Muller, company founder and president/CEO.

InfraReDx said that coronary angiography, the current standard of care, is unable to identify vulnerable plaque, so the company is hoping that its system could be used to identify the lipid-rich plaques in advance to allow for earlier treatment of potential problems.

NIR diffuse reflectance spectroscopy is a "highly developed technique," InfraReDx said, commonly used in fields such as chemistry and drug development to identify the chemical composition of substances.

"The identification of the chemicals present is based on the differential absorption of light in the NIR spectrum by different molecules," the company said. "An important feature of near-infrared light is that it can penetrate tissue and can therefore identify a tissue despite the presence of blood between the detector and the target. This is an important advantage for imaging within the human coronary artery."

There are challenges to using spectroscopy in the coronary arteries, InfraReDx said, chief among them problems of access, penetration of blood, motion and the need to scan. But those problems are now being overcome, it said, through advances in lasers and optical devices developed primarily for the telecommunications industry.

InfraReDx's system includes a laser light source, an automated pullback and rotation device and a small fiberoptic catheter.

Jay Caplan, vice president of research and development for the company, told Diagnostics & Imaging Week that the company's device "would be used in a patient who is already in a catheterization laboratory for a percutaneous coronary intervention with a guidewire and a guidewire catheter."

The procedures are performed under fluoroscopy, which are used to "determine locations of stenosis or other areas of interest in the arteries," he said.

"If the physician feels that more information may be needed about the artery segment, then they would use our device as an adjunct by essentially placing our catheter through the [rapid exchange] design on an existing guidewire and threading our catheter up into the artery," Caplan said.

The physician would then initiate a pullback of the internal imaging core within InfraReDx's catheter, after the tip of the catheter is "placed past the area of interest."

The InfraReDx device would then "scan the length of the artery and provide a map of the artery wall," on the now approved device's console, and those images are called Intravascular Chemograms.

"What we're doing is providing information about the chemical content of the vessel wall, which is different kind of information than is available today," Caplan said.

For example, angiography provides information about the structure of the vessel, and intravascular ultrasound provides cardiologist with information about the thickness of the vessel wall. InfraReDx hopes to fill the gap with its information that is provided about the presence of lipids and any other "chemicals of interest," InfraReDx said.

Nandini Murthy, vice president of clinical and regulatory affairs at InfraReDx, emphasized that the company has two studies under way with which it is attempting to determine an algorithm for the already cleared spectroscopy device also to be cleared to identify lipid-rich plaques.

A pivotal clinical study, called SPECTacle (Spectrascopic Assessment of Coronary Lipid, is designed to document the ability of the InfraReDx system to "identify distinctive near-infrared spectra in patients." A parallel study is being conducted in autopsy specimens. That study is a small clinical trial that involves patients at four centers in the U.S. and one in Canada, Murthy said.

InfraReDx said it recently closed a $22.3 million round of funding that will enable the company to complete the studies and finalize product development. That funding will also help the company begin efforts toward a product launch, which is anticipated in 2007.

InfraReDx expects, as Caplan indicated, that the first use of the device will involve patients undergoing percutaneous coronary intervention procedures such as stenting. There are about 2 million individuals who undergo such procedures each year, the company said.

Currently, there is no "formal" commercialization plan, Murthy said.

"Obviously, InfraReDx is very focused on finishing the research and the studies necessary to get 510(k) clearance for the lipid-rich indication, which is the real market opportunity we are going after," she told D&IW.