Coronary interventional devices: balloon, atherectomy, thrombectomy and distal protection devices

Safety and efficacy of thrombectomy in patients undergoing primary percutaneous coronary intervention for acute ST elevation MI: a meta-analysis of randomized controlled trials

BACKGROUND

Clinical trials comparing thrombectomy devices with conventional percutaneous coronary interventions (PCI) in patients with acute ST elevation myocardial infarction (STEMI) have produced conflicting results. The objective of our study was to systematically evaluate currently available data comparing thrombectomy followed by PCI with conventional PCI alone in patients with acute STEMI.

METHODS

Seventeen randomized trials (n = 3,909 patients) of thrombectomy versus PCI were included in this meta-analysis. We calculated the summary odds ratios for mortality, stroke, post procedural myocardial blush grade (MBG), thrombolysis in myocardial infarction (TIMI) grade flow, and post procedural ST segment resolution (STR) using random-effects and fixed-effects models.

RESULTS

There was no difference in risk of 30-day mortality (44/1914 vs. 50/1907, OR 0.84, 95% CI 0.54-1.29, P = 0.42) among patients randomized to thrombectomy, compared with conventional PCI. Thrombectomy was associated with a significantly greater likelihood of TIMI 3 flow (1616/1826 vs. 1533/1806, OR 1.41, P = 0.007), MBG 3 (730/1526 vs. 486/1513, OR 2.42, P < 0.001), STR (923/1500 vs. 715/1494, OR 2.30, P < 0.001), and with a higher risk of stroke (14/1403 vs. 3/1413, OR 2.88, 95% CI 1.06-7.85, P = 0.04). Outcomes differed significantly between different device classes with a trend towards lower mortality with manual aspiration thrombectomy (MAT) (21/949 vs.36/953, OR 0.59, 95% CI 0.35-1.01, P = 0.05), whereas mechanical devices showed a trend towards higher mortality (20/416 vs.10/418, OR 2.07, 95% CI 0.95-4.48, P = 0.07).

CONCLUSIONS

Thrombectomy devices appear to improve markers of myocardial perfusion in patients undergoing primary PCI, with no difference in overall 30-day mortality but an increased likelihood of stroke. The clinical benefits of thrombectomy appear to be influenced by the device type with a trend towards survival benefit with MAT and worsening outcome with mechanical devices.

Coronary ischemia and percutaneous intervention

The interventional treatment of ischemia is a complex issue grounded on an understanding of basic pathophysiology, but translated and implemented in practice by extensive clinical trial data representing patients with a spectrum of ischemia-causing clinical syndromes and anatomical variations of coronary artery disease (CAD). Percutaneous coronary intervention (PCI) has evolved to treat ischemia within this matrix of clinical and anatomical subsets using a wide array of techniques. Initial techniques using balloon angioplasty were promising, but demonstrated significant rates of restenosis due to negative arterial remodeling. The advent of stent technology prevented arterial recoil and provided a viable treatment for flow-limiting coronary dissections, thereby facilitating improved long-term patency of coronary vessels without the need for repeat revascularization. In-stent restenosis has been successfully addressed with drug elution, but late stent thrombosis has emerged as a complex issue involving dual antiplatelet therapy, patient compliance, and reexamination of the delicate balance between reducing restenosis and promoting endothelial proliferation. Finally, complex coronary lesions associated with heavy calcification or extensive plaque/thrombus burden that introduce unique challenges in obtaining ideal angiographic results have led to the development of new debulking devices aimed at optimizing procedural outcomes. This review will describe a variety of percutaneous coronary interventional techniques and technologies that are employed in the invasive treatment of ischemia under the guidance of clinical guidelines and evidence-based medicine.