Since the 2000s, thrombus aspiration (TA) has been widely used in the percutaneous coronary intervention (PCI) of ST elevated myocardial infarction (STEMI). Otherwise, recent trials have questioned its safety. Therefore, guidelines are against the routine use of manual TA during primary PCI.

Our study aimed to evaluate the immediate angiographic results of the TA to assess the predictive factors of its failure.

An observational prospective study was performed from 2016 to 2018. We included all patients who underwent TA using the ExportTM catheter during a primary PCI for less than 12h of STEMI. The primary endpoint was the failure of TA assessed by TIMI classification for the final coronary flow. Insufficient reperfusion due to failed TA was defined as a TIMI flow <3 in the culprit artery at the end of the PCI. The secondary composite endpoint was the occurrence of in-hospital Major Adverse CerebroCardiovascular Events (MACCE).

We have included 60 consecutive patients. Mean age was 59.7±13.6 years. 81.7% were males. Anterior location of STEMI was noted in 60%. The median delay between symptoms and wire crossing was 5 [3.8-8.7] hours. Initially, 68.3% of the patients presented a TIMI 0 flow and final TIMI 3 flow was established in 66.7% of cases. We identified 4 patients with in-hospital MACCE. Our results suggest a high rate of angiographic failure(33.3%) following a primary PCI despite the use of TA. The associate factors of a failure TA were: the delay between symptoms onset and wire crossing ≥5h(P=0.025) and a cardiogenic shock(P=0.04). The multivariate study showed that tardive presentation (>5h) was the only predictive factor of a failed TA HR=4 [1.1-14], P=0.037.

Despite the limitation of our observational study, we noted an important rate of slow and no flow in the setting of primary PCI despite using TA. Identifying such risk factors will improve the effectiveness of the primary PCI with a selective TA.