There was a small but statistically sig- ni cant increase in the rate of stroke in the aspiration thrombectomy group. An updated meta-analysis that included these 3 trials among a total of 17 trials (n 20,960) found no signi cant reduction in death, reinfarction, or stent thrombosis with routine aspiration thrombectomy. Aspiration thrombectomy was associated with a small but nonsigni cant increase in the risk of stroke (33). Several previous studies have found that higher thrombus burden in patients with STEMI is independently associated with higher risks of distal embolization, no- re ow phenomenon, transmural myocardial necrosis, major adverse cardiac events, stent thrombosis, and death (38 42). However, subgroup analyses from the TASTE and TOTAL trials did not suggest relative bene t from aspira- tion thrombectomy before primary PCI in patients with higher thrombus burden or in patients with initial Throm- bolysis in Myocardial Infarction (TIMI) ow grade 0 1 or left anterior descending artery/anterior infarction (34,35). On the basis of the results of these studies, the prior Class IIa recommendation for aspiration thrombectomy has been changed. Routine aspiration thrombectomy before primary PCI is now not recommended (Class III: No Bene t, LOE A). There are insuf cient data to assess the Recommendation 2015 Focused Update Recommendations Comments Class IIa Class IIb Manual aspiration thrombectomy is reasonable for patients undergoing primary PCI (29 32). (Level of Evidence: B) The usefulness of selective and bailout aspiration thrombectomy in patients undergoing primary PCI is not well established (33 37). (Level of Evidence: C-LD) Modi ed recommendation (Class changed from IIa to IIb for selective and bailout aspiration thrombectomy before PCI). Class III: No Bene t Routine aspiration thrombectomy before primary PCI is not useful (33 37). 