Feasibility and safety of thrombectomy with TVAC aspiration catheter system for patients with acute myocardial infarction

Use of Thrombectomy Devices in Primary Percutaneous Interventions for ST-elevation Myocardial Infarction - An Update

Primary percutaneous coronary intervention (PPCI) is the preferred reperfusion modality in patients with ST-elevation myocardial infarction (STEMI). While PPCI is highly effective in achieving epicardial coronary reperfusion, a significant proportion of patients fail to achieve adequate myocardial reperfusion. This is in part due to the distal microembolisation of thrombus and plaque debris during PCI. Recognition of this has led to the development of a number of devices with different mechanisms of action that aim to reduce such distal embolisation and therefore improve end myocardial perfusion. Study results of thrombectomy devices however have been largely inconsistent, especially about clinical outcome data, and several meta-analyses have been carried out as a result. This review aims to critically analyse the literature data on thrombectomy during PPCI, taking into account the most recent studies and the latest meta-analyses looking to see whether thrombectomy use is associated with improved outcomes.

A review of thrombectomy devices

Acute coronary syndrome is associated with a high incidence of thrombus. The presence of coronary thrombus is often not appreciated on coronary angiography; however, simultaneous use of angioscopy or intravascular ultrasound increases the detection of thrombus. Forceful coronary injection, passage of intracoronary devices, balloon angioplasty and stenting in the presence of thrombus contribute to distal embolization by disrupting the thrombus. Clinically, intracoronary thrombus is associated with higher rates of death, myocardial infarction and target vessel revascularization. Removal of thrombus results in the improvement of markers of perfusion, which includes resolution of ST segment elevation, higher myocardial blush grade, and an increase in final thrombolysis in myocardial infarction flow as well as lower mortality. In this article, the authors discuss different mechanical thrombectomy devices and the literature available for their use in acute coronary syndrome.

Utility of Thrombectomy in Primary Percutaneous Coronary Intervention

Thrombectomy in the setting of primary percutaneous coronary intervention allows for improved macrovascular and microvascular perfusion, possible limitation of infarct size, and the preservation of left ventricular function and myocardial viability. The beneficial tissue level effects of thrombectomy have translated into an improvement in cardiovascular mortality. A variety of thrombectomy devices are currently available, including aspiration thrombectomy catheters and rheolytic catheters. A review of the various types of thrombectomy devices available, clinical evidence for their use, clinical pearls for use, and device troubleshooting are presented.

Manual versus nonmanual thrombectomy in primary and rescue percutaneous coronary angioplasty

Although many thrombectomy devices have been tested in ST-segment elevation acute myocardial infarction (STEMI), there are no comparative data on safety or effectiveness in thrombectomy or ST-segment resolution. This study compares manual versus nonmanual thrombectomy devices in patients undergoing primary or rescue percutaneous coronary intervention in a tertiary care center. We identified 232 consecutive patients with STEMI and time from symptom onset to emergency room contact of < or = 12 h undergoing percutaneous coronary intervention with coronary thrombectomy devices. Primary end point was ST-segment resolution of > or = 70%. Several angiographic, procedural and clinical secondary end points were also evaluated. The manual thrombectomy group included 110 patients and the nonmanual group 122 patients. Both groups were similar in their clinical characteristics. The primary end point occurred with similar frequency in patients treated with manual versus nonmanual thrombectomy (67.9% vs 60.0%, P = 0.216). No significant differences were found in the two groups with regard to procedural complications, angiographic reperfusion parameters, in-hospital major adverse cardiac events, or infarct size, whereas manual thrombectomy was associated with a better left ventricle ejection fraction at discharge. Furthermore, treatment with a manual thrombectomy device was associated with significantly shorter procedural times (69 min vs 95 min, P < 0.001) and lower procedural costs (2981 euros vs 7505 euros, P < 0.001). The use of manual thrombus-aspiration catheters appeared equivalent to nonmanual thrombectomy devices in the setting of primary or rescue percutaneous intervention in terms of clinical efficacy, and led to shorter procedures and cost savings.

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.