Direct Stenting after Thrombus Removal before Primary Angioplasty in Acute Myocardial Infarction

Abstract

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. 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. 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. 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. DS during PPCI reduces distal embolization and improves myocardial reperfusion. This effect is significantly more relevant after thrombus aspiration.