Effects of aspiration thrombectomy on necrosis size and ejection fraction after transradial percutaneous coronary intervention in acute ST-elevation myocardial infarction.

Background: The use of routine aspiration thrombectomy in primary percutaneous coronary intervention (PCI) remains controversial.
Methods: Patients in the EArly Discharge after Transradial Stenting of CoronarY Arteries in Acute Myocardial Infarction (n = 105) study were treated with aspirin, clopidogrel, and abciximab within 6 hr of symptoms onset. Operators were allowed to use 6 Fr Export aspiration catheter at their discretion. In this observational analysis, we compared acute and late results in patients treated with and without thrombectomy using cardiac biomarkers, angiographic, cardiovascular magnetic resonance (CMR), and clinical parameters.
Results: Patients in the thrombectomy group (n = 44) had longer symptoms to balloon time (196 ± 86 min vs. 164 ± 62, P = 0.039) and higher incidence of preprocedural TIMI flow grade 0 or 1 (84% vs. 64%, P = 0.028). Following PCI, both groups had similar incidence of TIMI flow grade 3 (93 vs. 92%, P = 0.73) and myocardial blush grade 2 or 3 (80 vs. 77%, P = 0.86), respectively. Patients in thrombectomy group had significantly higher post-PCI maximum values of creatine kinase-MB (P = 0.0007) and troponin T (P = 0.0010). Accordingly, post-PCI myocardial necrosis by CMR was higher (P = 0.0030) in patients in the thrombectomy group. At 6-month follow-up, necrosis size remained higher (20.7% ± 13.3% vs. 13.5% ± 11.1%, P = 0.012) in the thrombectomy group. Ejection fraction at 6 months was 65% ± 9% in patients in thrombectomy group compared to 70% ± 11% in patients without (P = 0.070). Results were not affected by initial TIMI flow or symptoms to balloon time. Clinical events remained comparable in both groups at 12 months follow-up.
Conclusion: In patients with ST-segment elevation myocardial infarction presenting within 6 hr of symptoms and undergoing primary angioplasty with maximal antiplatelet therapy, acute and late results did not suggest significant benefit for additional aspiration thrombectomy, irrespective of initial TIMI flow or total ischemic time.
(Copyright © 2010 Wiley-Liss, Inc.)