Background: Thrombus aspiration is applicable in a large majority of patients with acute myocardial infarction (AMI) and results in better reperfusion and clinical outcomes compared with percutaneous coronary intervention alone. Some aspiration procedures are, however, ineffective. To date, few clinical data are available on the predictors of successful thrombectomy in the acute phase of myocardial infarction.
Aims: To determine the baseline clinical and angiographic characteristics associated with successful thrombectomy.
Methods: Consecutive patients with ST elevation myocardial infarction with a baseline TIMI flow of 0 or 1, who underwent thrombus aspiration and primary or rescue angioplasty, were included. The main criterion for evaluation was an effective or ineffective aspiration defined, respectively, by the presence or absence of atherothrombotic material in the aspirate samples.
Results: Among the 180 patients included, material was collected in 155 patients (86%). Patients with the presence of material were younger (61 vs 74 years, P=0.015), less frequently hypertensive (41% vs 68%, P=0.023) and had a lower systolic blood pressure at admission (135 vs 148 mmHg, P=0.031). No difference was observed between the two groups for angiographic parameters except for visible thrombus (61% vs 28%, P=0.005) and calcification (37% vs 60%, P=0.048). In multivariable analysis, the ability to remove the clot was affected by: age greater than 70 years (odds ratio 0.18, 95% confidence interval 0.06-0.51; P=0.001), admission systolic blood pressure (0.97, 0.95-0.99; P=0.003) and thrombus seen on angiography (4.54, 1.54-13.45, P=0.006).
Conclusion: The present study showed that manual thrombus aspiration is effective in most, but not all, patients. Further studies are needed to develop more efficient aspiration techniques and other aspiration devices to improve the results of such procedures.
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