A Medical Device Daily

Physicians and researchers now have access to a non-invasive fingertip test designed to identify patients with the earliest stages of cardiovascular disease and replace testing that is done during angiography.

The device, called the Endo-PAT 2000 and developed by Itamar Medical (Caesarea, Israel/Boston), uses the PAT (Peripheral Arterial Tone) signal to identify patients with endothelial dysfunction, which the company said "is well recognized as an early stage of generalized atherosclerosis and coronary artery disease."

The Endo-PAT 2000 was developed by Itamar, which has pioneered the use of the PAT signal into clinical applications in cardiology and sleep medicine. The device consists of two disposable finger probes connected to a portable unit and a laptop computer that analyzes the patient's data using signal processing software.

The Endo-PAT was evaluated in clinical research conducted at major centers such as the Mayo Clinic (Rochester, New York), Harvard University (Cambridge, Massachusetts), New England Medical Center (Boston) and Yale University (New Haven, Connecticut) and published recently in the Journal of the American College of Cardiology.

"All of the currently available tests for the assessment of endothelial function are more or less invasive or operator-dependent, which precludes their use as a screening tool for endothelial dysfunction in clinical practice," said study author Amir Lerman, MD, of the Mayo Clinic. "This test is non-invasive, operator-independent and [is an] easy-to-perform technique to assess peripheral endothelial function that has the potential to become a valuable tool for cardiovascular risk stratification in daily clinical practice."

In the study, the data collected from the portable device and fingertip probes was compared against the gold standard invasive test of intra-coronary acetylcholine challenge, which requires the patient to undergo an invasive procedure during angiography. The non-invasive Endo-PAT was found to be equally predictive of coronary artery endothelial dysfunction as the invasive test. The FDA cleared the Endo-PAT in November 2003. And Itamar has signed its first U.S. distribution agreement with Cholestech (Hayward, California), which focuses on point-of-care diagnostics.

The Endo-PAT already is used by research centers worldwide to explore further clinical, public health and research applications and is available for purchase within a research package scheme, offered by Itamar, it said. The test also is available to pharmaceutical companies that are using it to assess the impact of new therapies on endothelial function. It recently has been incorporated into the Framingham Heart Study as an investigational device.

Prior to the Endo-PAT, there were no FDA-approved non-invasive devices available to researchers and physicians to reliably assess endothelial function, according to Itamar. Endothelial dysfunction is increasingly recognized as an early stage in the development of atherosclerosis, which is at the core of cardiovascular and cerebrovascular diseases and complications of diabetes that lead to potentially fatal outcomes such as heart attack and stroke.

Many commonly used therapies, including statins that are used to modify cholesterol levels and angiotensin converting enzyme (ACE) inhibitors that are used to treat high blood pressure, where shown to improve endothelial function. New, more potent drugs are expected to enter the market within a few years.

"The Endo-PAT is the fifth PAT product to receive FDA clearance, and we will continue work with leading researchers and organizations worldwide to develop, commercialize and bring this important new physiologic signal to medical practice," said Dr. Koby Sheffy, vice president and chief technology officer at Itamar. "We started last year expanding the clinical research with the Endo-PAT into new areas where it is expected to have much contribution such as diabetes, early assessment in children, erectile dysfunction and others."