Heart attack test at your fingertips

Hey there, time traveller!
This article was published 28/03/2009 (6264 days ago), so information in it may no longer be current.

A new study shows that a simple finger sensor test is "highly predictive" of a pending heart attack or stroke for people considered to be at low or even moderate risk.

The non-invasive device, called EndoPAT, uses two probes that hook up to each index finger to measure blood flow. The device evaluates endothelial cells, which are the cells that line blood vessels regulating blood flow. If the endothelial cells are not working properly, the arteries may harden leading to a greater risk of cardiovascular diseases.

"(It’s) a process where you occlude (stop the flow of) the blood to the arm for five minutes and then release it, and the response to this overshoot of flow is a parameter of the function of endothelia," said Dr. Amir Lerman, a cardiologist at the Mayo Clinic and senior author of the study.

"If this response is normal, it’s indicative of normal vascular function, normal endothelial function. If this response is abnormal then it tells you the vascular vessels are not functioning well, which indicates there is endothelial dysfunction."

He said the device will help classify patients who are at a high risk for heart disease or stroke. "We believe these tests will allow us to discriminate for patients who are at higher risks for an (heart attack or stroke) event, which will in the future or even now modify how you treat this patient."

The device takes 15 minutes to use and contains a machine with two prongs and a blood pressure cuff. A reading of the blood flow is taken through the prongs for three timed readings.

The Mayo Clinic researchers tested the EndoPAT on 270 low- to medium-risk patients between the ages of 42 and 66, and followed their progress from August 1999 to August 2007. The patients were declared low to medium risks based on their Framingham Risk Score, a common test for heart disease. Of the 270 test subjects, 49 per cent of those with a low endothelia function suffered a cardiac event within the test period. "If we divide the patients based on their endothelial marker, 130 of the patients had a low index and from them, 53 patients had a (cardiac) event. From the patients that had a normal index (140), only 34 had a (cardiac) event. So the higher event rate was in the patient with a low index," Lerman said.

The EndoPAT device is approved by the U.S. Food and Drug Administration, but Health Canada has not given the device the green light yet. In Canada, cardiovascular disease kills more people than any other disease, based on the latest data from Statistics Canada. However, the Heart and Stroke Foundation reports that the rate has declined 25 per cent over the past 10 years.

Although there are other non-invasive methods to test for heart disease, such as ultrasounds and electrocardiograms, the EndoPAT is unique. "It’s very simple and straightforward to use, which means it doesn’t need physician interpretation. One unique thing about this device is that the other hand services the control. That means the patient services the control, which means you eliminate environmental factors that may affect the vascular activity, which does not exist in other devices," Lerman said.

— Canwest News Service