Cardiac troponin (I or T) is the preferred biomarker for the definition of acute MI, although less sensitive biomarkers such as the creatine kinase-MB (CKMB) mass can still be used when cardiac troponin is not available, said Dr. Thygesen, with the department of cardiological medicine, Aarhus (Denmark) University.
The criteria for an acute MI include detection of a rise and/or fall of cardiac biomarker values exceeding the 99th percentile URL, plus at least one of the following:
• Symptoms of ischemia.
• New or presumably new significant ST-segment/T wave changes or new LBBB.
• Development of pathological Q waves in the ECG.
• Imaging evidence of new loss of viable myocardium or new regional wall motion abnormality.
• Identification of an intracoronary thrombus by angiography or autopsy.
The new MI definition is expected to become the gold standard for diagnosis and to be adopted by the U.S. Food and Drug Administration for use in clinical trial protocols accepted by the agency. This is significant because it will help standardize the way MI is defined in clinical trials, making comparisons between studies more meaningful, Dr. Thygesen observed.
The expert consensus document, as well as pocket versions, are available on the websites of the ESC, ACC, AHA, and World Heart Federation.
The document is also being copublished in five journals: the Journal of the American College of Cardiology, European Heart Journal, Circulation, Global Heart, and Nature Reviews of Cardiology.
Dr. Thygesen reported no conflicts of interest. Dr. Alpert reported consulting for several pharmaceutical firms as well as the North American Center for Continuing Medical Education.