Time for contrast material to traverse the epicardial artery and the myocardium in ST-segment elevation acute myocardial infarction versus unstable angina pectoris/non-ST-elevation acute myocardial infarction.

Although the time for contrast material to fill the epicardial artery in the setting of acute coronary syndromes has been studied extensively, the time for contrast material to fill the myocardium has not been evaluated. We compared differences in myocardial contrast material transit among patients with unstable angina pectoris/non-ST-elevation acute myocardial infarction (UAP/NSTEAMI) with patients with ST-elevation acute myocardial infarction (STEAMI). The time it took for contrast material to first appear and to arrive at peak intensity in the myocardium was compared in 224 patients with STEAMI enrolled in the LIMIT-AMI study versus 430 patients with UAP/NSTEAMI enrolled in the TACTICS-TIMI 18 trial.

Elevations in troponin T and I are associated with abnormal tissue level perfusion: a TACTICS-TIMI 18 substudy. Treat Angina with Aggrastat and Determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis in Myocardial Infarction.

Background: Cardiac troponin T (cTnT) and I elevations are associated with a higher risk of adverse events, a higher incidence of multivessel disease, complex lesions, and visible thrombus in the setting of non-ST elevation (NSTE) acute coronary syndromes (ACS). Other pathophysiological mechanisms underlying troponin elevation remain unclear.

Methods And Results: We evaluated the relationship between troponin elevation and tissue level perfusion using the TIMI myocardial perfusion grade (TMPG) in 310 patients with NSTE-ACS in the Treat Angina with Aggrastat and Determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis in Myocardial Infarction (TACTICS-TIMI) 18 trial.