Abstract

Gibson, C. M., Marble, S. J., Rizzo, M. J., Moynihan, J., McLean, C., Ryan, K., Sparano, A., Piana, R. N., McCabe, C., Cannon, C. P. Relation between injections before 90-minute angiography and coronary patency: results of the thrombolysis in myocardial infarction 4 trial American heart journal. 1997;134(3):351-4.

The current goal of thrombolytic therapy is to achieve both full (Thrombolysis in Myocardial Infarction [TIMI] grade 3) and early reperfusion. Newer reperfusion strategies may now achieve a high degree of reperfusion even earlier than the traditional 90-minute end point. To determine whether injections before 90 minutes affect this traditional end point, the relation between the number of injections before 90-minute angiography and patency was examined in the TIMI 4 trial. The number of injections before 90-minute angiography was no different between occluded arteries (TIMI grade 0/1 flow) (2.46 +/- 1.78; n = 94) and patent arteries (TIMI grade 2/3 flow) (2.71 +/- 2.42; n = 295) (p = 0.24). The incidence of any injections before 90 minutes was no different in patent versus closed arteries (80.6% [77/98] vs 72.4% [22/304]; p = 0.10). The number of injections before 90 minutes was insignificantly smaller in patients with TIMI grade 3 flow (2.53 +/- 2.53 [n = 184] vs 2.76 +/- 2.03 [n = 204]; p = 0.31), but the incidence of any injections before 90 minutes was significantly smaller in patients with TIMI grade 3 flow (68.8% [132/192] vs 79.5% [167/210]; p = 0.01). No relation was identified between the number of injections before 90-minute angiography and patency at this traditional time point. This observation justifies the judicious use of a limited number of "earlier snapshots" of the infarct-related artery before 90 minutes to ascertain just how rapidly newer thrombolytic regimens achieve patency. Patients with TIMI grade 3 flow had a slightly lower incidence of injections before 90 minutes, perhaps because they did not require as urgent a definition of coronary anatomy.

Trial: TIMI 4