New blood test to help differentiate heart attack from heart strain

Atheer – Oman News Agency

A new blood test developed by a University of Alberta physician promises to eliminate the guesswork that clinicians face in differentiating a heart attack from heart strain.

At present, the standard test used for the clinical diagnosis of myocardial infarction, the cardiac troponin blood test, doesn’t indicate the extent of cardiac damage, explained Peter Hwang, a clinician-scientist in the Faculty of Medicine and Dentistry.

Cardiac troponin is a protein unique to the heart, meaning that elevated levels in the blood indicate that the heart has been damaged.

After digging deeper into what’s going on in the troponin release process, Hwang found that patients with a true heart attack had more fragmented troponin than those with increased cardiac strain.

“We postulated that when cells die during a heart attack, not only would they release troponin into the bloodstream, but they would also digest the troponin through the action of activated intracellular proteases, enzymes that digest other proteins,” he said.

The study included 29 inpatients from the University of Alberta Hospital and Mazankowski Heart Institute, with elevated troponin levels either with known heart attacks, or other conditions that increase cardiac demand.

“As predicted, we found that the degree of proteolytic digestion increased with increasing severity of heart injury,” added Hwang.

“The highest degree was observed in patients with type 1 MI, where you have an acute blockage of a coronary artery, while the least degree was found in patients with type 2 MI, where the heart is just working harder.”

Hwang added that, while the existing troponin test is still very useful, the new test would enable clinicians to make objective decisions regarding treating patients when faced with less clear-cut situations.