Abstract

Gibson, C. M., Cannon, C. P., Murphy, S. A., Marble, S. J., Barron, H. V., Braunwald, E. Relationship of the TIMI myocardial perfusion grades, flow grades, frame count, and percutaneous coronary intervention to long-term outcomes after thrombolytic administration in acute myocardial infarction Circulation. 2002;105(16):1909-13.

BACKGROUND: Although 90-minute TIMI flow grades (TFGs), corrected TIMI frame counts (CTFCs), and TIMI myocardial perfusion grades (TMPGs) have been associated with 30-day outcomes, we hypothesized that these indices would be related to long-term outcomes after thrombolytic administration.

METHODS AND RESULTS: As a substudy of the TIMI 10B trial (tissue plasminogen activator versus tenecteplase), 49 centers carried out 2-year follow-up. TIMI grade 2/3 flow (Cox hazard ratio [HR] 0.41, P=0.001), reduced CTFCs (faster flow, P=0.02), and an open microvasculature (TMPG 2/3) (HR 0.51, P=0.038) were all associated with improved 2-year survival. Rescue percutaneous coronary intervention (PCI) of closed arteries (TFG 0/1) at 90 minutes was associated with reduced mortality (P=0.03), and mortality trended lower with adjunctive PCI of open (TFG 2/3) arteries (P=0.11). In a multivariate model correcting for previously identified correlates of mortality (age, sex, pulse, left anterior descending coronary artery infarction, and any PCI during initial hospitalization), patency (TFG 2/3) (HR 0.32, P<0.001), CTFC (P=0.01), and TMPG 2/3 remained associated with reduced mortality (HR 0.46, P=0.02).

CONCLUSIONS: Both improved epicardial flow (TFG 2/3 and low CTFCs) and tissue-level perfusion (TMPG 2/3) at 90 minutes after thrombolytic administration are independently associated with improved 2-year survival, suggesting complementary mechanisms of improved long-term survival. Although rescue PCI reduced long-term mortality, improved microvascular perfusion (TMPG 2/3) before PCI was also related to improved mortality independently of epicardial blood flow and the performance of rescue or adjunctive PCI. Further prospective trials are warranted to re-examine the benefit of early PCI with thrombolysis.

Trial: TIMI 10B