Medical Device Daily

A new study could give heart stress tests like Cheetah Medical (Tel Aviv, Israel) a chance at becoming the standard for patient care, replacing expensive and more difficult testing options.

The study evaluated bioreactance-based noninvasive measurements during exertion; identified abnormalities of cardiovascular function and how it might be useful for indexing disease severity, prognostication, and for tracking responses to treatment in clinical practice and trials.

Nearly 240 patients were observed in the study, which compared Cheetah Medical's Nicom System to the traditional method of measuring oxygen consumption, through Vo2 tests which are obtained from analysis of expired gases. Results were published earlier this month in the Journal of Cardiac Failure, the official journal of the Heart Failure Society of America (St. Paul, Minnesota) and the Japanese Heart Failure Society.

"The issue is to determine a patient's rate of heart failure," Cheetah Medical CEO Yoav Avidor told Medical Device Daily.

Bioreactance technologies are non-invasive and measure cardiac output, and other hemodynamic variables such as stroke volume, cardiac index, left ventricular ejection time and thoracic fluid content.

The company said that the results from both methods correlated extremely well, demonstrating the potential to use the Nicom system to routinely monitor heart failure patients without the significant limitations of expired breath gas technologies.

Cheetah said the study gave evidence Bioreactance-based noninvasive measurements of CO at rest and during exertion identified abnormalities of cardiovascular function consistent with those identified by VO2 and in prior studies using invasive CO measurements. This technique might therefore be useful for indexing disease severity, prognostication, and for tracking responses to treatment in clinical practice and in clinical trials.

The problem with expired breath technologies and VO2 tests is that they are expensive and some physicians and clinicians have very limited experience with this type of technology.

"These tests aren't readily available and are expensive," Avidor told MDD. "The other problem is that these tests are very difficult because you could stress the heart while administering the test."

But the Nicom system, which is FDA cleared and has been given the CE mark, is a much smaller and inexpensive way to measure cardiac output.

"The sensors for the device are four double electrodes similar in concept to an ECG and are placed on the back of the patient, creating a square like shape," Avidor told MDD. "What we do is non invasively measure cardiac output, without putting too much stress on the heart."

The philosophy behind the device is to observe organ perfusion and oxygen delivery because these two factors drive changes in cardiac function, vascular tone, blood pressure respiration and urine output. Therefore, monitoring oxygen delivery provides key insight into the patient's hemodynamic status in a more accurate and real-time fashion than any dependant proxy such as blood pressure, urine output, heart and the like.

The company said that this information provides key clinical insight, especially in challenging hemodynamic clinical settings, or in those where such challenges may quickly occur and rapidly deteriorate. Understanding oxygen delivery in real time means understanding how to treat the patients' heart function, fluid balance and respiratory function.

But what happens next for the company and the device? The answer is quite simple according to Daniel Burkhoff, MD, PhD. an Adjunct Associate Professor of Medicine at Columbia University Medical School (New York).

"With the results of this study showing good correlations to oxygen consumption and several prior independent studies showing that peak cardiac power can be even more predictive of outcomes, we are encouraged that we will see these measurements used more often in a variety of settings," he said. "Currently, the NICOM appears to offer the simplest solution for clinicians to measure cardiac output and power during exercise. We are planning a large multicenter study to confirm the prior smaller studies to prove the utility of peak cardiac power for predicting the risks of hospitalizations, the need for heart transplant, left ventricular assist devices and mortality."

Cheetah Medical specializes in non invasive cardiac output and hemodynamic monitoring. The company is private and was founded in 2001.

Omar Ford; 404-262-5546

Omar.Ford@ahcmedia.com