Test may quickly diagnose heart attack

One of the most common reasons people go to the emergency room is for serious chest pains. Time is crucial when someone is having a heart attack.  If doctors don't make a diagnosis quickly, it can mean the difference between life and death.

Now, there may be a new tool to help ER doctors make a quicker diagnosis.  A new highly sensitive test can detect troponin, a protein in the muscle tissue, according to new research in this week's Journal of the American Medical Association (JAMA) .  According to cardiologists, the higher the levels of troponin, the more likely it is a person will have a heart attack. If tropin isn't present, the likelihood of a heart attack is much smaller.

Researchers say this new test could also help physicians monitor patients who present with chest pains but no heart attack symptoms in the hours after being admitted to the hospital.

"Early identification of individuals at high and intermediate risk for myocardial ischemia (insufficient blood flow to the heart muscle) is crucial because they benefit the most from early and aggressive treatment," said the study's authors.

Those who evaluated the procedure commented that the key to the new test, over other troponin tests on the market, is its sensitivity. "Highly sensitive troponin assays (tests) have been developed recently that reliably assess troponin levels in more than 50 percent of the general population. The reliable detection of very low troponin concentrations using these new highly sensitive assays in the acute setting might pose a challenge in everyday clinical practice," explained the study authors.

The research, conducted out of the University Heart Center Hamburg, Germany, evaluated the diagnostic performance of the newly developed highly sensitive troponin I test (hsTnI) compared with another, less sensitive troponin test (cTnI) and how well and how quickly they diagnosed a heart attack.

The study included 1,818 patients with cardiac issues such as high risk of heart attacks or angina and who were enrolled at chest pain units in Germany from 2007 to 2008.

Out of all the patients in the study, 22.7% (413 patients) had acute MI. Both hsTnI and cTnI were superior to the other evaluated diagnostic biomarkers in detecting these coronary problems. But investigators found the hsTnl test was more sensitive to the protein biomarker in patients who were just showing signs of a possible heart attacks than the cTnl test. The hsTnl test was also almost 100 percent accurate (98.2%) in patients who were tested within three hours of entering the ER.

"The shortcoming of conventional troponin assays (test) with low sensitivity within the first hours after chest pain onset led to the evaluation of various so-called early biomarkers in the diagnosis of MI. In our study, the diagnostic information of hsTnI was superior to all other evaluated biomarkers alone, " noted the German authors.