الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Primary Percutaneous coronary intervention is the preferred treatment of STEMI. Thrombus aspiration devices has the potential for reducing distal embolization and improving microvascular perfusion. However, procedural and clinical outcomes of thrombectomy showed contradictory results, early trials suggested improved surrogate and clinical outcome, whereas, subsequent large trial reported no additional benefit and increased risk of stroke.
Moreover, most of thrombectomy studies until now included patients with variable grades of thrombus burden, leaving open the question of whether the benefits of routine thrombus aspiration could be obtained with a strategy of selective thrombectomy in patients with large thrombus burden.
Therefore, this prospective study was designed to evaluate the impact of selective use of manual thrombus aspiration and PCI guided by angiographic thrombus burden for STEMI patients, on procedural and clinical outcomes during hospital stay, at 6 and 18 months follow up.
Sixty five patients with large thrombus burden (Thrombus grade ≥4) were assigned to thrombus aspiration+ PCI ± GP IIB/IIIA inhibitors (group I) and sixty seven patients with small thrombus burden (Thrombus grade ≤ 3) were assigned to conventional PCI ± GP IIb/IIIa inhibitors (group II).
Baseline demographic, clinical and laboratory characteristics of the patients as well as PCI procedural data and major adverse cardiac events during follow up and post PCI echocardiography during hospital stay were recorded.
Study Outcomes: Procedural success of the intervention was defined by the achievement of TIMI flow grade 3 & MBG ≥ 2 with a residual stenosis of ≤ 20% assessed by quantitative coronary angiography. Primary outcome was composite MACE of cardiac mortality, reinfarction, TVR, or stroke, TIA during hospital stay, 6 months and 18 months after PPCI. The key safety outcome was stroke within 30 days.
Subgroup analysis: Subgroups analysis defined according to age (≤65 years, >65 years), diabetes, smokers, total ischemic time > 6 hours, allocation of myocardial infarction (anterior, non anterior) and initial TIMI flow ≤1 was done using composite MACE at 18 months to highlight on superiority of selective use of thrombus aspiration in any of the prespecified subgroups.
Results
Regarding baseline characteristics, age, sex, prevalence of risk factors and history of previous MI, PCI or CVS showed insignificant difference, with relatively higher current smokers in LTB. LTB group showed significantly longer chest pain to ER (6.88 ± 5.2 vs 5.25 ± 3.5 hrs) & total ischemic time (7.9 ±5.29 vs 6.3 ± 3.47 hrs, P=0.04), more Killip class IV (7.7 % vs1.5 %, p= 0.11), more high Grace risk score > 155 (13.8% vs 10.4 %, p= 0.8), more anterior MI (58.5% vs 38.8%, P=0.02) and higher WBCS (11.97 ± 3.51 vs 10.56 ± 3.61/ml, P=0.017 P=0.01) as compared to STB group. Logistic multivariate regression analysis demonstrated that Long chest pain to ER is the strongest independent predictor for LTB.
In terms of procedural characteristics, LTB presented significantly with higher initial TIMI 0 flow (89% vs 38.8%, p<0.001) and culprit LAD (58.5% vs 38.8%,p=0.02) with no difference in syntax score. Direct stenting was performed more frequently in TA group (63.1% vs 22.4%, p<0.001). TA group demonstrated comparable technical success rate to PCI alone group regarding improving epicardial and myocardial reperfusion assessed by TIMI flow III, MBG ≥ 2 and ST resolution (> 70%) with tendency for insignificant higher no reflow.
Regarding Post PCI echocardiographic study, LVEF% showed insignificantly lower mean value in TA group than PCI alone (50 ± 10.7 vs 53.5 ± 12.6%, p=0.092).
Composite MACE rates showed insignificant difference between TA and PCI alone groups during hospital stay (4.6% vs 1.5%, P= 0.67), 6 months (4.6% vs 3%, P=0.43) and 18 months (7.7% vs 7.5%, P=0.27). Non-significant lower cardiac mortality (0% vs 3%,P=0.5), reinfarction (3% vs 6%,P=0.7), similar TVR (2% both, P=1.00) and insignificant increase in stroke (4.6% vs 1.5%, P=0.36) were observed in TA group at 18 months.
Subgroups analysis defined according to age, diabetes, smokers, total ischemic time > 6 hours, allocation of myocardial infarction and preprocedural TIMI flow≤ 1 failed to identify superiority of selective thrombus aspiration in any of the prespecified subgroups.
In conclusion, Thrombus burden guided treatment strategies for PPCI showed that selective manual thrombus aspiration as an adjunct to PPCI in LTB achieved comparable success rate in restoration of myocardial perfusion with low incidence of complications and long term clinical outcomes to that of PPCI alone in STB despite differences in thrombus load and patient risk stratification. Also, the beneficial impact of thrombus aspiration on composite MACE in the long term follow up was counterbalanced by the increased risk of stroke.