Direct stenting after thrombus removal before primary angioplasty in acute myocardial infarction

OBJECTIVES: To verify whether direct stenting (DS) after thrombus removal during primary angioplasty (PPCI) in patients with ST-elevation acute myocardial infarction (STEMI) can improve myocardial reperfusion and prevent distal embolization compared to conventional stent implantation. BACKGROUND: Both mechanical removal and DS reduce thrombus dislodgment and improve microcirculatory reperfusion during PPCI. However, the additional effect of DS after thrombus removal has not been definitely assessed. METHODS: The DEAR-MI study included 148 consecutive STEMI patients who were randomly assigned to undergo or not thrombus aspiration before PPCI. For the purpose of the present study, we interrogated the DEAR-MI data bank to compare the occurrence of complete (>70%) ST-segment resolution (STR), myocardial blush grade (MBG)-3, no-reflow, and angiographic embolization in patients treated and untreated with DS. RESULTS: Clinical and angiographic characteristics were similar in the two groups. Comparing DS and no-DS groups, complete STR was found in 67% versus 51% (P = 0.08), MBG-3 in 86% versus 49% (P < 0.001), no-reflow in 1% versus 14% (P < 0.01), angiographic embolization in 3% versus 19% (P < 0.01), TIMI flow-3 in 89% versus 70% (P < 0.01), and the corrected TIMI frame count was 16.2 versus 18.8 (P < 0.05). Among patients undergoing thrombus aspiration, the odds ratio of DS for MBG-3 and distal embolization was 4 (95% CI 1-16.6) and 0.10 (95% CI 0.01-0.93), respectively. At multivariable analysis, thrombus aspiration (P < 0.001) and DS (P < 0.05) independently predicted MBG-3, while thrombus aspiration was the only independent predictor of DS. CONCLUSIONS: DS during PPCI reduces distal embolization and improves myocardial reperfusion. This effect is significantly more relevant after thrombus aspiration.