The role of thrombectomy and distal protection devices during percutaneous coronary interventions

Achievement of the angiographic gold standard TIMI 3 flow (Thrombolysis in Myocardial Infarction) flow grade during PCI (percutaneous coronary intervention) in the setting of AMI (acute myocardial infarction) is insufficient for attainment of optimal prognostic benefit, as there is a poor prognosis for patients with evidence of inadequate flow at the tissue level despite patent coronary arteries. PCI in lesions containing thrombus are associated with an increased risk of complications occurring through dislodgement of thrombotic material resulting and distal embolisation leading to slow flow or even no-reflow. Devices which remove thrombus from coronary arteries (thrombectomy devices) or protect from distal embolisation of thrombus (distal protection devices) are increasingly used in PCI.

We have performed a systematic review of the literature to investigate the role of these devices in PCI in the setting of AMI. Use of thrombectomy devices in randomised and multicentre trials in patients undergoing PCI during STEMI is associated with a significant benefit in a number of markers of myocardial perfusion including MBG (myocardial blush grade), ST segment resolution and improvement of distal embolisation, although no significant benefits in mortality have been observed.

There does not appear to be strong evidence for the use of embolic protection devices and distal filter devices in the setting of primary PCI in native coronary arteries, although evidence from trials such as the SAFER trial would make a strong case for their use in SVG interventions.