MRI Hyperenhancement is Associated with Myonecrosis Following PCI All Patients Have TIMI 3 Flow at Completion of Stenting Lecture Notes Recently Ricciardi et al used MRI to evaluate the pathophysiology of CK release following PCI. They found that among patients with CK release following PCI, there are white areas of hyperenhancement (shown by the arrow) on MRI. These areas of hyperenhancement are consistent with necrosis and were not observed among patients who did not sustain CK release following PCI. These areas of hyperenhancement persist for one year following PCI as shown in the bottom panels. References 1. Ricciardi M et al, Circulation 2001: 103: 2780-2783. Ricciardi M et al, Circulation 2001: 103: 2780-2783.

Decline in post-stent TMPG Impaired TMPG is Associated with MRI Hyperenhancement; A Decline in TMPG after Stenting is Associated with Larger Infarct Sizes = Ramondo et al,Catheter Cardiovasc Interv 2004;61:222–226. CK-MB p=0.01 HE mass p=0.04 No Yes 10 20 30 40 50 1 2 3 4 Decline in post-stent TMPG All patients had normal epicardial TIMI Grade 3 Flow before PCI 12 of 14 patients had normal TMPG 3 before PCI Only 7 of 14 had normal TMPG 3 after PCI HE mass (gm) CK-MB (ng/dL) Lecture Notes Recently at the ACC, Ricciardi et al demonstrated that the MRI and the blush on the angiogram were in near unanimous agreement in identifying those patients with CK release following PCI. Also of note, all patients entered the cath lab with normal epicardial blood flow, and 12 of 14 patients had normal tissue level perfusion before the stent was placed. However, following stent placement there was a decline in tissue level perfusion in 7 out of 14 patients. Among those patients with a decline in TMPG following stent placement, the CK rise was significantly greater (p=0.01), and the grams of tissue infarcted (estimated from the size of the hyperenhanced tissue) was also greater (p=0.04). Reference: 1. Ricciardi MJ, Choi JW, Murphy SA, Davidson CJ, Kim RJ, Gibson CM. Myonecrosis following stent placement: Association between impaired TIMI myocardial perfusion grade (TMPG) and MIR visualization of microinfarction. 2002 American College of Cardiology Meeting. Ricciardi, Gibson et al, CCD 2004