Update on Non-ST-Elevation Acute Coronary Syndromes

By James de Lemos, M.D.
Professor of Internal Medicine

I had the opportunity to chair a packed session in the “main tent” focusing on state-of-the-art concepts surrounding the pathology, diagnosis, and treatment of non-ST-elevation acute coronary syndromes (NSTE-ACS). Over the course of five lectures by international experts, multiple emerging concepts were introduced and controversies discussed. Advances in intracoronary imaging techniques, particularly optical coherence tomography and intravascular ultrasound, now allow more precise characterization of the mechanisms underlying ACS. We now recognize that it is not uncommon to have myocardial infarction with nonobstructive coronary arteries (MINOCA), a phenomenon caused by diverse pathophysiological mechanisms including coronary embolism and spontaneous coronary dissection, as well as functional abnormalities in the coronary epicardial and microvascular circulation. Until we begin to systematically investigate these patients, we will not be able to move toward a pathophysiology-guided approach to treatment. 

Another important topic discussed was the introduction into the U.S. practice of high-sensitivity troponin assays. A multidisciplinary team at UT Southwestern and Parkland Hospital has developed an innovative protocol that capitalizes on the improved sensitivity and precision of the “high sensitivity” troponin T assay (hs-cTnT) to “rule out” MI more effectively and quickly. We were among the very first centers to implement hs-cTnT testing in the U.S. and the first to report our findings. Earlier this year in Circulation, we reported very favorable results from a pilot study of our new protocol.