Impact of TIMI 3 patency before primary percutaneous coronary intervention for ST-elevation myocardial infarction on clinical outcome: results from the ASSENT-4 PCI study.

BACKGROUND: Early restoration of blood flow of the infarct-related artery is associated with an improved outcome in patients with ST-elevation myocardial infarction (STEMI). Previous studies have shown a low mortality in patients with TIMI 3 flow before primary percutaneous coronary intervention (PCI). Most likely these patients had spontaneous recanalization of the infarct vessel and might constitute a low-risk subgroup. The purpose of the present analysis was to investigate whether TIMI 3 flow obtained with fibrinolysis before PCI is associated with a clinical outcome comparable to that in patients with spontaneous TIMI 3 flow. METHODS: Patients with STEMI <6 hours enrolled in the ASSENT-4 PCI study were randomized to facilitated PCI with tenecteplase or primary PCI. For this analysis, patients were divided into three groups according to the TIMI flow of the infarct vessel before PCI: TIMI 0/1, TIMI 2, and TIMI 3. RESULTS: From a total of 1617 patients, 861 had TIMI 0/1, 279 had TIMI 2, and 477 TIMI 3 flow. The rates of TIMI 3 flow after PCI were 84.6, 89.7, and 95.6%, respectively. Complete ST resolution was observed most often in the TIMI 3 flow group (47.5, 53.6, and 58.6%). The incidence of cardiogenic shock (6.2, 5.5, and 3.6%) and 90-day mortality (6.1, 4.7, and 4.0%) were lowest in the group with TIMI 3 patency before PCI, respectively. The rate of TIMI 3 flow before PCI was higher in the facilitated PCI group than in the primary PCI group (43.9 vs. 15.2%). The 90-day mortality in patients with TIMI 3 before PCI was identical in the facilitated and the primary PCI groups (14/353, 4.0% vs. 5/124, 4.0%). CONCLUSION: In this post-hoc analysis of ASSENT-4 PCI, TIMI grade 3 flow in the infarct-related artery before PCI, occurring either spontaneously or obtained by fibrinolysis, is associated with a higher TIMI patency after PCI, better improved ST resolution and a trend towards a favourable clinical outcome after 90 days.

Duke Scholars

Author Christopher Bull Granger Medicine, Cardiology

Author Paul Wayne Armstrong Medicine, Cardiology