Thrombus aspiration during primary percutaneous coronary intervention improves myocardial reperfusion and reduces infarct size: the EXPIRA (thrombectomy with export catheter in infarct-related artery during primary percutaneous coronary intervention) prospective, randomized trial

Adjunctive thrombectomy for acute myocardial infarction: A bayesian meta-analysis

BACKGROUND

In available trials and meta-analyses, adjunctive thrombectomy in acute myocardial infarction (MI) improves markers of myocardial reperfusion but has limited effects on clinical outcomes. Thrombectomy devices simply aspirate thrombus or mechanically fragment it before aspiration. Simple aspiration thrombectomy may offer a distinct advantage.

METHODS AND RESULTS

We identified 21 eligible trials (16 that used a simple aspiration thrombectomy device) involving 4299 patients with ST-segment elevation MI randomized to reperfusion therapy by primary percutaneous coronary intervention with or without thrombectomy. By using Bayesian meta-analysis methods, we found that thrombectomy yielded substantially less no-reflow (odds ratio [OR], 0.39; 95% credible interval [CrI], 0.18 to 0.69), more ST-segment resolution > or =50% (OR, 2.22; 95% CrI, 1.60 to 3.23), and more thrombolysis in myocardial infarction/myocardial perfusion grade 3 (OR, 2.50; 95% CrI, 1.48 to 4.41). There was no evidence for a decrease in death (OR, 0.94; 95% CrI, 0.47 to 1.80), death, recurrent MI, or stroke (OR, 1.07; 95% CrI, 0.63 to 1.92) with thrombectomy. Restriction of the analysis to trials that used simple aspiration thrombectomy devices did not yield substantially different results, except for a positive effect on postprocedure thrombolysis in myocardial infarction grade 3 flow (OR, 1.49; 95% CrI, 1.14 to 1.99).

CONCLUSIONS

In this Bayesian meta-analysis, adjunctive thrombectomy improves early markers of reperfusion but does not substantially effect 30-day post-MI mortality, reinfarction, and stroke. The use of aspiration thrombectomy devices is not associated with a reduction in post-MI clinical outcomes. Thrombectomy is one of the rare effective preventive measures against no-reflow.

Coronary microembolization: from bedside to bench and back to bedside

Coronary microembolization from the erosion or rupture of a vulnerable atherosclerotic plaque occurs spontaneously in acute coronary syndromes and iatrogenically during percutaneous coronary interventions. Typical consequences of coronary microembolization are microinfarcts with an inflammatory response, contractile dysfunction, and reduced coronary reserve. Apart from transient elevations of creatine kinase and troponin, microemboli can be visualized by intracoronary Doppler and the resulting microinfarcts by late-enhancement nuclear magnetic resonance. Statins, antiplatelet agents, and coronary vasodilators protect against microembolization and microinfarction when started before percutaneous coronary interventions. Distal protection devices can retrieve atherothrombotic debris and prevent its embolization into the microcirculation, but their effect on clinical outcome has been disappointing so far, except for saphenous vein bypass grafts. Devices for aspiration of thrombi and thrombus-derived vasoconstrictor, thrombogenic, and inflammatory substances, however, reduce thrombus burden, improve perfusion, and provide protection in patients with acute myocardial infarction.

Current status of distal embolization in percutaneous coronary intervention: mechanical and pharmacological strategies

Distal embolization during percutaneous coronary intervention for acute myocardial infarction or saphenous vein graft disease may result in microvascular obstruction and the 'no-reflow' phenomenon. The incidence of distal embolization ranges from 2 to 42% in saphenous vein graft intervention and from 6 to 15% in primary percutaneous coronary intervention and is associated with impaired myocardial perfusion and poor outcome. Several mechanical and pharmacological strategies have been proposed to prevent or to treat embolization in percutaneous coronary intervention and have been tested in clinical trials. The pivotal role of distal embolization in the pathophysiology of microvascular obstruction will lead to the further development of preventive and therapeutic strategies. Strategies to counteract distal embolization and future directions are discussed in this review.

Intracoronary versus intravenous abciximab in ST-segment elevation myocardial infarction: rationale and design of the CICERO trial in patients undergoing primary percutaneous coronary intervention with thrombus aspiration

Background

Administration of abciximab during primary percutaneous coronary intervention is an effective adjunctive therapy in the treatment of patients with ST-segment elevation myocardial infarction. Recent small-scaled studies have suggested that intracoronary administration of abciximab during primary percutaneous coronary intervention is superior to conventional intravenous administration. This study has been designed to investigate whether intracoronary bolus administration of abciximab is more effective than intravenous bolus administration in improving myocardial perfusion in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention with thrombus aspiration.

Methods/Design

The Comparison of IntraCoronary versus intravenous abciximab administration during Emergency Reperfusion Of ST-segment elevation myocardial infarction (CICERO) trial is a single-center, prospective, randomized open-label trial with blinded evaluation of endpoints. A total of 530 patients with STEMI undergoing primary percutaneous coronary intervention are randomly assigned to either an intracoronary or intravenous bolus of weight-adjusted abciximab. The primary end point is the incidence of >70% ST-segment elevation resolution. Secondary end points consist of post-procedural residual ST-segment deviation, myocardial blush grade, distal embolization, enzymatic infarct size, in-hospital bleeding, and clinical outcome at 30 days and 1 year.

Discussion

The CICERO trial is the first clinical trial to date to verify the effect of intracoronary versus intravenous administration of abciximab on myocardial perfusion in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention with thrombus aspiration.

Trial registration

ClinicalTrials.gov NCT00927615

Clinical impact of thrombectomy in acute ST-elevation myocardial infarction: an individual patient-data pooled analysis of 11 trials

AIMS

Thrombectomy in patients with ST-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI) is associated to better myocardial reperfusion. However, no single trial was adequately powered to asses the impact of thrombectomy on long-term clinical outcome and to identify patients at higher benefit. Thus, we sought to assess these issues in a collaborative individual patient-data pooled analysis of randomized studies (study acronym: ATTEMPT, number of registration: NCT00766740).

METHODS AND RESULTS

Individual data of 2686 patients enrolled in 11 trials entered the pooled analysis. Primary endpoint of the study was all-cause mortality. Major adverse cardiac events (MACE) were considered as the occurrence of all-cause death and/or target lesion/vessel revascularization and/or myocardial infarction (MI). Subgroups analysis was planned according to type of thrombectomy device (manual or non-manual), diabetic status, IIb/IIIa-inhibitor therapy, ischaemic time, infarct-related artery, pre-PCI TIMI flow. Clinical follow-up was available in 2674 (99.6%) patients at a median of 365 days. Kaplan-Meier analysis showed that allocation to thrombectomy was associated with significantly lower all-cause mortality (P = 0.049). Thrombectomy was also associated with significantly reduced MACE (P = 0.011) and death + MI rate during the follow-up (P = 0.015). Subgroups analysis showed that thrombectomy is associated to improved survival in patients treated with IIb/IIIa-inhibitors (P = 0.045) and that the survival benefit is confined to patients treated in manual thrombectomy trials (P = 0.011).

CONCLUSION

The present large pooled analysis of randomized trials suggests that thrombectomy (in particular manual thrombectomy) significantly improves the clinical outcome in patients with STEMI undergoing mechanical reperfusion and that its effect may be additional to that of IIb/IIIa-inhibitors.

Individual patient-data meta-analysis comparing clinical outcome in patients with ST-elevation myocardial infarction treated with percutaneous coronary intervention with or without prior thrombectomy. ATTEMPT study: a pooled Analysis of Trials on ThrombEctomy in acute Myocardial infarction based on individual PatienT data

Background:

Available data from randomized trials on thrombectomy in patients with ST-elevation myocardial infarction (STEMI) have shown favorable trends in myocardial reperfusion. However, few data are available on the effect of thrombectomy on clinical outcome. Thus we have designed a collaborative individual patient-data meta-analysis which aimed to assess the long-term clinical outcome in STEMI patients randomized to percutaneous coronary intervention (PCI) with or without thrombectomy.

Method:

After a thorough database search, the principal investigators of randomized trials comparing thrombectomy with standard PCI in patients with STEMI were contacted. Principal investigators as authors of 11 randomized studies agreed to participate and were asked to complete a structured database by providing a series of key pre-PCI clinical and angiographic data as well as the longest available clinical outcome of the patients enrolled in the corresponding trial. The primary end-point of this pooled analysis is the comparison of overall survival rates between patients randomized to PCI with thrombectomy or PCI without thrombectomy. The secondary end-points are survival free from myocardial infarction (MI), target lesion revascularization (TLR), major adverse coronary events (MACE: death + MI + TLR) and death + MI between patients randomized to PCI with thrombectomy or PCI without thrombectomy. A pre-defined subgroup analysis is planned considering the following variables: type of thrombectomy device used, diabetes, rescue PCI, IIb/IIIa-inhibitors use, time-to-reperfusion, infarct-related artery, and pre-PCI TIMI flow.

Implications:

This study will provide useful data on the effect of the reported improved myocardial perfusion associated with thrombectomy on the long-term clinical outcome in patients with STEMI.