Improved heart-disease tests
FIVE simple medical tests together provide a broader and more accurate assessment of heart-disease risk than currently used methods, cardiologists at University of Texas South western Medical Centre have found.
Combined, results from the five tests – an EKG (electrocardiogram), a limited CT scan, and three blood tests – better predict who will develop heart disease compared with standard strategies that focus on blood pressure, cholesterol, diabetes, and smoking history, researchers reported.
“This set of tests is really powerful in identifying unexpected risk among individuals with few traditional risk factors. These are people who would not be aware that they are at risk for heart disease and might not be targeted for preventive therapies,” said Dr James de Lemos, professor of internal medicine.
The five tests, and the information they provide are: a 12lead EKG provides information about hypertrophy, or thickening of the heart muscle; a coronary calcium scan, a low-radiation imaging test, identifies calcified plaque build-up in the arteries of the heart; a blood test for C-reactive protein indicates inflammation; a blood test for the hormone NT-pro-BNP indicates stress on the heart; and a blood test for high-sensitivity troponin T indicates damage to heart muscle. Troponin testing is regularly used by hospitals to diagnose heart attacks, but high-sensitivity troponin finetunes that measure, pointing to small amounts of damage that can be detected in individuals without any symptoms or warning signs.
Four of the five tests are currently readily available and the fifth – high-sensitivity troponin T – will be available soon.
Researchers used data from two large population studies, including the Dallas Heart Study, that each followed a large group of healthy individuals for more than a decade. Their study was partly funded by Nasa to develop strategies for predicting heart disease in astronauts.
The new study focused on a broader spectrum of cardiovascular disease events rather than only those related to cholesterol plaque build-up, as traditional risk assessment does.
“A major focus of this study is to expand the scope of risk prediction beyond just heart attack and stroke. We believe that people are interested in the whole portfolio of heart problems that can develop including heart failure and atrial fibrillation,” said Dr Amit Khera, professor of internal medicine and director of UT South Western’s Preventive Cardiology Programme.
The set of five tests not only expanded risk prediction to include the likelihood of heart failure and atrial fibrillation, but also proved to be a better predictor of heart attacks and strokes. Heart failure is a chronic condition in which the heart progressively weakens and atrial fibrillation is a heart rhythm problem.
“There has been a real need to bring modern science to the problem of heart disease risk prediction, which has relied on traditional risk factors for decades,” said De Lemos. “We wanted to determine whether advances in imaging and blood-based biomarkers could help us to better identify who was at risk for heart disease.”
The added value of the test panel results from the careful selection of tests that were complementary but not redundant, Khera said.
Both researchers emphasised, however, that these tests aren’t for everyone and should only be done in collaboration with a physician, to help interpret the results.– Staff reporter.