Optimization in stent implantation by manual thrombus aspiration in ST-segment-elevation myocardial infarction: findings from the EXAMINATION trial

Background: Manual thrombus aspiration (TA) is effective to reduce the thrombus burden during primary percutaneous coronary intervention for ST-elevation myocardial infarction. The objective of this study is to assess the impact of manual TA on stent implantation during primary percutaneous coronary intervention.

Methods and results: Population of the EXAMINATION trial (n=1498) was divided into 2 groups according to the use of TA. Immediate angiographic results, primary patient-oriented end point (combination of all-cause death, myocardial infarction, and any revascularization) and secondary device-oriented end point (combination of cardiac death, target vessel myocardial infarction, and clinically driven target lesion revascularization), definite/probable stent thrombosis, and major/minor bleeding were evaluated at 2 years. A total of 976 (65.2%) patients were classified into TA group and 522 (34.8%) patients into nonthrombus aspiration group. Manual TA was most frequently used in patients with worse initial thrombolysis in myocardial infarction flow. The TA group received less number of stents implanted (1.35 ± 0.62 versus 1.45 ± 0.71, P = 0.005) with bigger size (3.25 ± 0.44 versus 3.11 ± 0.46 mm, P < 0.001) compared with the nonthrombus aspiration group. A higher rate of direct stenting (69.2% versus 43.3%, P < 0.001) with lower rate of postdilatation (13.0% versus 18.0%, P < 0.009) was also present in the TA group compared with the nonthrombus aspiration group. At 2-year follow-up, no differences in clinical end point were observed between groups.

Conclusions: Manual TA during primary percutaneous coronary intervention is associated with a higher rate of direct stenting, a lower rate of postdilatation, and larger and less stents in comparison with conventional primary percutaneous coronary intervention. Conversely, manual TA had no apparent impact on clinical outcomes at long-term follow-up.

Clinical trial registration: http://www.clinicaltrials.gov. Unique identifier: NCT00828087.