Thrombus aspiration in ST-elevation myocardial infarction: Does it actually impact long-term outcome?

Background: The effect of thrombus aspiration on mortality is still controversial, with results which are often inconsistent in different randomized trials, real world registries and different follow-up duration. The aim of this analysis was to assess the effect on 30-day and 1-year mortality of thrombus aspiration during primary percutaneous coronary intervention (pPCI) for ST-elevation myocardial infarction (STEMI) compared with conventional PCI.

Methods: We used data from all the consecutive STEMI patients treated either with conventional PCI or thrombus aspiration between January 1, 2004 and January 1, 2012. Propensity matching score was calculated on the basis of several baseline and procedural characteristics in order to predict the probability for each patient of having been treated with thrombus aspiration. This propensity score analysis was used in order to select a cohort of patients treated with thrombus aspiration matched one-to-one with patients treated with conventional PCI.

Results: In total, 744 (53.1%) patients out of 1,400 enrolled were treated with thrombus aspiration. In the matched cohort, at 30-day follow-up 6.3% of patients in the conventional PCI group died compared to 4.7% in the thrombus aspiration group. The unadjusted hazard ratio (HR) for 30-day mortality was 1.01 (95% CI 0.33-3.14, p = 0.985). In the same cohort, 10.7% of patients died at 1-year in the conventional PCI group compared to 5.2% in the thrombus aspiration group. The 1-year unadjusted hazard ratio for mortality was 0.47 (95% CI 0.25-0.90, p = 0.025). The HR changed and was no longer significant after adjustment for differences in the use of glycoprotein (GP) IIb/IIIa inhibitors, lesion pre-dilatation and pre-procedural TIMI flow: 0.71 (95% CI 0.36-1.39, p = 0.322).

Conclusions: Thrombus aspiration does not influence 30-day mortality, however it is associa­ted with 1-year survival benefit. GP IIb/IIIa inhibitors and thrombus aspiration may have an important synergistic role in leading to this long-term benefit.