Impact of manual thrombectomy on myocardial reperfusion as assessed by ST-segment resolution in STEMI patients treated by primary PCI.

BACKGROUND: In STEMI patients treated by primary PCI, damage of the microvascular circulation caused by distal embolization of thrombotic material affects the quality of myocardial reperfusion. Important controversies remain concerning the usefulness of the manual thrombectomy to improve myocardial perfusion. The aim of this study is to evaluate the impact of manual thrombectomy on ST resolution as a surrogate of reperfusion extent.

METHODS: Two hundred and thirty-nine consecutive STEMI patients with an <12 hours onset of symptoms, were enrolled in an observational registry. Patients were divided into two cohorts according to the reperfusion strategy: manual thrombectomy before primary PCI (n=102) or conventional-PCI (n=137). The primary endpoint was the post procedural frequency of complete (>70%) resolution of ST segment elevation.

RESULTS: A complete resolution of ST segment elevation occurred in 51.4% of patients in the thrombectomy group and in 35,6% of those in the conventional-PCI group (P=0.018). Thrombectomy strategy was associated with a lower use of stents. Multivariate analysis identified manual thrombectomy (HR=2.08 IC 95% (1.01-4.26); P=0.046), inferior location and short ischemic delay (<180 min) as independent predictors of ST resolution. The cumulative Kaplan-Meier estimate of MACE was not significantly different between the two groups at one, three years follow-up.

CONCLUSION: In STEMI patients, manual thrombectomy improves myocardial reperfusion as assessed by the percentage of ST segment resolution and a lower use of stents. However, in this cohort of limited size, this strategy did not translate into an improved cardiovascular outcome at one year follow-up.