Impact of Aspiration Thrombectomy on Microvascular Obstruction in Patients With ST-segment Elevation Myocardial Infarction.

Background: Primary percutaneous coronary intervention (PPCI) is the gold standard for myocardial reperfusion in ST-segment elevation myocardial infarction (STEMI). Numerous studies have shown that thrombus aspiration can prevent distal embolization and reducing the risk of microvascular obstruction (MVO). Cardiac magnetic resonance (CMR) is considered the gold standard for the evaluation of MVO.

Objectives: The aim of this study was to evaluate the effect of thrombus aspiration in STEMI patients as an adjunctive technique to primary PCI in reducing both incidence and extent of MVO evaluated by CMR.

Methods: Ninety-three patients with heavy thrombus burden were enrolled in this study; sixty-five patients met our inclusion criteria. After failed trial of restore the artery patency, aspiration thrombectomy was done followed by PCI for thirty-one patients (aspiration group), while conventional PCI without aspiration thrombectomy was performed for 34 patients (conventional group). The primary end points were both occurrence and extent of microvascular obstruction (MVO) evaluated mainly by CMR, in addition to angiographic data (MBG and TIMI flow grade).

Results: The incidence of microvascular obstruction (MVO) was significantly higher in conventional group (18 patients, 52.9 %) when compared with aspiration group (7 patients, 22.6 %; p-value = 0.012). Moreover, significant differences existed between the studied groups regarding MVO extent. For instance, MVO extended to >4 segments in only 3 patients (9.7 %) in aspiration group, but in 13 patients in conventional group (38.2 %; p-value = 0.007).

Conclusions: Aspiration thrombectomy substantially reduces both the incidence and extent of microvascular obstruction as an adjunctive technique to PPCI in STEMI patients with heavy thrombus burden.