Test for low fingertip temperature detects coronary plaque
Results of five clinical studies evaluating the predictive value of VENDYS, a new FDA-approved cardiovascular test, were presented at the 2009 Annual Scientific Sessions of the American College of Cardiology in Florida.
The studies indicate that a simple, inexpensive test that measures temperature changes at the fingertips can help detect hidden coronary artery disease.
Results from hundreds of tests of patients at the Cardiac CT Laboratory at Harbor UCLA, have consistently shown a strong correlation between low fingertip temperature rebound and a high burden of coronary plaques, said Dr Mathew Budoff (right), Associate Professor of Medicine and Director of the laboratory. ‘The lower the temperature rebound, the more plaque build-up and blockage. This is truly amazing! This test is the only non-invasive, non-imaging, office-based test that I am aware of with such a high predictive value for detection of high risk coronary patients. We are seeing similar results in CT angiography, as well as nuclear, studies.’
The researchers examined patients with the new test before they underwent coronary CT angiography and a thallium nuclear scan. Those with coronary blockage and abnormal scan results often had low fingertip temperature reactivity. The team also studied apparently healthy individuals with a family history of heart disease, or with other cardiovascular risk factors. They discovered that the lower the fingertip thermal reactivity, the higher the chance of having a coronary blockage or calcium score >100 — both of which would place those individuals at a high risk of a future heart attack.
They now hope that, by measuring a dynamic marker of vascular disease, the test can fill the gap in existing cardiovascular risk assessment and complement traditional risk factor measurements as well as advanced, structural imaging tests, such as CAT scan and MRI.
‘The technology was originally developed at our laboratory in the Texas Heart Institute while working on vulnerable plaque detection,’ explained the VENDYS inventor Dr Morteza Naghavi. ‘Despite exciting developments in intracoronary plaque characterisation, it became obvious to me that we needed a non-invasive and inexpensive way to screen and monitor at risk patients, simply because you can’t cath asymptomatic people, nor can you put stable patients into CT or MRI machine every three months to evaluate their progress. Frankly, at the time, I didn’t expect it to be so surprising in terms of its predictive value compared to risk factors. But now, looking at the data, it makes sense, because it does not measure an individual risk factor, like cholesterol; instead, it reflects vascular function, which is affected by numerous risk and protective factors, much like blood pressure. Furthermore, unlike coronary calcium or carotid IMT, it is a dynamic marker and changes quickly with the progression and regression of the disease.’
Dr Harvey Hecht, Chairman of the Endothelix Scientific Advisory Board and Director of Cardiovascular Computed Tomography at Lenox Hill Heart and Vascular Institute added; ‘In terms of sensitivity and specificity for the detection of high risk patients, its area under the ROC curve is well above all traditional risk factors put together. If these findings are corroborated by others, it will be the first non-imaging test that has exhibited a predictive value close to that of imaging tests, which obviously are far more expensive and less suitable for mass screening.’
01.05.2009
