Thrombus aspiration before primary angioplasty improves myocardial reperfusion in acute myocardial infarction: the DEAR-MI (Dethrombosis to Enhance Acute Reperfusion in Myocardial Infarction) study

Additive benefit of glycoprotein IIb/IIIa inhibition and adjunctive thrombus aspiration during primary coronary intervention: results of the Initial Thrombosuction and Tirofiban Infusion (ITTI) trial

BACKGROUND

Thrombus aspiration has been shown to provide significant benefits during primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). The aim of the current study was to evaluate the additional benefit of tirofiban to thrombus aspiration during primary PCI in myocardial reperfusion.

METHODS

100 STEMI patients were randomized according to a 2 × 2 factorial design into 1 of the 4 groups: standard PCI, PCI with initial thrombus aspiration (IT), PCI with tirofiban infusion (TI), and PCI with both treatments (IT+TI).

RESULTS

The myocardial blush grade (MBG) 3 was achieved in 30.4%, 45.8%, 56% and 78.6% in the 4 groups respectively. More frequent MBG 3 (p=0.015) and complete (>70%) ST-segment resolution (STR, 67.9% vs. 41.7%, p=0.058) were observed in IT ± TI group compared with IT group. If actuarial analysis was done after reassigning the 2 TI patients who crossed over to IT+TI, the difference between IT+TI and IT groups became more significant (MBG 3 rates: 76.7% vs. 45.8%, p=0.009; complete STR rates: 70% vs. 41.7%, p=0.036). Infusion of tirofiban resulted in improved MBG and STR (p=0.003 and 0.037, respectively). Thrombus aspiration resulted in improved MBG only (p=0.048) but not in STR. 6-month MACE (death, reinfarction, target lesion revascularization and stroke) was similar among groups (p=0.725).

CONCLUSIONS

Tirofiban may augment thrombus aspiration therapy on myocardial reperfusion in primary PCI. The benefit of thrombus aspiration treatment without tirofiban might be less significant, especially on resolution of ST-segment elevation.

Prevention and treatment of microvascular obstruction-related myocardial injury and coronary no-reflow following percutaneous coronary intervention: a systematic approach

Microvascular obstruction (MVO) commonly occurs following percutaneous coronary interventions (PCI), may lead to myocardial injury, and is an independent predictor of adverse outcome. Severe MVO may manifest angiographically as reduced flow in the patent upstream epicardial arteries, a situation that is termed "no-reflow." Microvascular obstruction can be broadly categorized according to the duration of myocardial ischemia preceding PCI. In "interventional MVO" (e.g., elective PCI), obstruction typically involves myocardium that was not exposed to acute ischemia before PCI. Conversely "reperfusion MVO" (e.g., primary PCI for acute myocardial infarction) occurs within a myocardial territory that was ischemic before the coronary intervention. Interventional and reperfusion MVO have distinct pathophysiological mechanisms and may require individualized therapeutic approaches. Interventional MVO is triggered predominantly by downstream embolization of atherosclerotic material from the epicardial vessel wall into the distal microvasculature. Reperfusion MVO results from both distal embolization and ischemia-reperfusion injury within the subtended ischemic tissue. Management of MVO and no-reflow may be targeted at different levels: the epicardial artery, microvasculature, and tissue. The aim of the present report is to advocate a systematic approach to prevention and treatment of MVO in different clinical settings. Randomized clinical trials have studied strategies for prevention of MVO and no-reflow; however, the efficacy of measures for reversing MVO once no-reflow has been demonstrated angiographically is unclear. New approaches for prevention and treatment of MVO will require a better understanding of intracellular cardioprotective pathways such as the blockade of the mitochondrial permeability transition pore.

[Thromboaspiration in primary angioplasty for ST elevation myocardial infarction]

Primary angioplasty is the gold standard for myocardial reperfusion in patients with acute myocardial infarction with ST elevation (STEMI). Fast normalization of infarct-related coronary artery flow and no reflow prevention are correlated with clinical outcomes. Over the last years, many antithrombotic regimens have been evaluated in this setting. The use of a combined pharmacological and mechanical strategy with abciximab, and thromboaspiration of atherothrombotic debris is associated with coronary flow improvement, improvement of myocardial perfusion, and, in fine a better clinical outcome. In this respect, the current guidelines recommend a systematic manuel catheter thromboaspiration of the culprit lesion in STEMI with a class IIa, level of evidence A indication.

Thrombus aspiration followed by direct stenting: a novel strategy of primary percutaneous coronary intervention in ST-segment elevation myocardial infarction. Results of the Polish-Italian-Hungarian RAndomized ThrombEctomy Trial (PIHRATE Trial)

BACKGROUND

Previous studies with thrombectomy showed different results, mainly due to use of thrombectomy as an additional device not instead of balloon predilatation. The aim of the present study was to assess impact of aspiration thrombectomy followed by direct stenting.

METHODS

Patients with ST elevation myocardial infarction (STEMI) <6 hours from pain onset and occluded infarct-related artery in baseline angiography were randomized into aspiration thrombectomy followed by direct stenting (TS, n = 100) or standard balloon predilatation followed by stent implantation (n = 96). The primary end point of the study was the electrocardiographic ST-segment elevation resolution >70% (STR > 70%) 60 minutes after primary angioplasty (percutaneous coronary intervention [PCI]). Secondary end points included angiographic myocardial blush grade (MBG) after PCI, combination of STR > 70% immediately after PCI and MBG grade 3 (optimal myocardial reperfusion), Thrombolysis In Myocardial Infarction flow after PCI, angiographic complications, and in-hospital major adverse cardiac events.

RESULTS

Aspiration thrombectomy success rate was 91% (crossing of the lesion with thrombus reduction and flow restoration). There was no significant difference in STR ≥ 70% after 60 minutes (53.7% vs 35.1%, P = .29). STR > 70% immediately after PCI (41% vs 26%, P < .05), MBG grade 3 (76% vs 58%, P < .03), and optimal myocardial reperfusion (35.1% vs 11.8%, P < .001) were more frequent in TS. There was no difference in between the groups in 6-month mortality (4% vs 3.1%, P = .74) and reinfarction rate (1% vs 3.1%, P = .29).

CONCLUSIONS

Aspiration thrombectomy and direct stenting is safe and effective in STEMI patients with early presentation (<6 hours). The angiographic parameters of microcirculation reperfusion and ECG ST-segment resolution directly after PCI were significantly better in thrombectomy group despite the lack of the difference in ST-segment resolution 60 minutes after PCI.

Thrombus aspiration in primary percutaneous coronary intervention in high-risk patients with ST-elevation myocardial infarction: a real-world registry

OBJECTIVES

To evaluate the effect of thrombus aspiration in a real-world all-comer patient population with STEMI undergoing primary PCI.

BACKGROUND

Catheter thrombus aspiration in primary PCI was beneficial in randomized clinical trials.

METHODS

We enrolled 313 STEMI patients presenting with TIMI Flow Grade 0 or 1 in the infarct related artery at baseline angiogram undergoing primary PCI. PATIENTS were divided in two groups based on whether thrombus aspiration was attempted. This decision was left at operator's discretion. Procedural and long-term clinical outcomes were compared between the two groups.

RESULTS

Baseline characteristics were similar between groups: 194 (62%) received thrombus aspiration and 119 underwent conventional PCI. Thrombus aspiration was associated with significantly lower post-PCI TIMI Frame Count values (19 +/- 15 vs. 25 +/- 17; P = 0.002) and higher TIMI Flow Grade 3 (92% vs. 73%; P < 0.001). Postprocedural myocardial perfusion assessed by myocardial blush grade (MBG) was significantly increased in the thrombus aspiration group (MBG 3: 44% vs. 21%; P < 0.001). No significant difference was found between the two groups in clinical outcome at 30 days. At one year, patients treated with thrombus aspiration showed significantly higher overall survival (HR 0.41, 95% CI 0.20-0.81; log-rank P = 0.010) and MACE-free survival (HR 0.49, 95% CI 0.28-0.85; log-rank P = 0.011).

CONCLUSIONS

In real-world all-comer STEMI patients with occluded infarct-related artery, thrombus aspiration prior to PCI improves coronary flow, myocardial perfusion, and long-term clinical outcome as compared with PCI in the absence of thrombus aspiration.

Impact of thrombectomy with EXPort Catheter in Infarct-Related Artery during Primary Percutaneous Coronary Intervention (EXPIRA Trial) on cardiac death

In ST-segment elevation myocardial infarction (STEMI) impairment of microcirculatory function is a negative independent predictor of myocardial function recovery. In the Impact of Thrombectomy with EXPort Catheter in Infarct-Related Artery during Primary Percutaneous Coronary Intervention (PCI; EXPIRA) trial we found that manual thrombectomy resulted in a better myocardial reperfusion expressed by an improved procedural outcome and a decrease of infarct size compared to conventional PCI. The aim of the present study was to investigate whether the early efficacy of thrombus aspiration translates into very long-term clinical benefit. We randomized 175 patients with STEMI with occlusive thrombus at baseline undergoing primary PCI to thromboaspiration with a manual device (Export Medtronic, n = 88) or standard PCI (n = 87). No differences in baseline, clinical, and angiographic preprocedural findings were observed between the 2 groups except for incidence of hypertension and cholesterol levels. After 24 months major adverse cardiac events were 13.7% versus 4.5% (p = 0.038, log-rank test) and cardiac death was 6.8% versus 0% (p = 0.012, log-rank test). A strict correlation was observed between cardiac death incidence and tissue reperfusion parameters (postprocedural myocardial blush grade and ST-segment resolution). In conclusion, manual thrombus aspiration before stenting of the infarct-related artery in selected patients with STEMI improving myocardial reperfusion significantly decrease cardiac death and major adverse cardiac events at 2 years.

Thrombus aspiration in a series of patients with stable or unstable angina pectoris and lesion-site thrombus formation

Background. In acute myocardial infarction, thrombus aspiration prior to percutaneous coronary interventions (PCI) is often beneficial, but this approach has never been studied in patients without acute myocardial infarction. The aim of this retrospective study is to shed light on that topic based on our initial experience with manual thrombus aspiration in patients with stable or unstable angina pectoris and angiographic evidence of lesion-site thrombus. Methods. We assessed the feasibility (thrombus aspiration without predilatation) of this approach; in addition, we determined angiographic coronary flow and myocardial blush grade. Results. During 33 months in which a total of 4725 PCI were performed in our centre, manual thrombus aspiration was attempted in 14 patients with stable or unstable angina pectoris with angiographic evidence of thrombus. In nine of these 14 patients, the aspiration catheter could be advanced into the lesion without predilatation; in eight patients visible thrombus was obtained. The corrected TIMI frame count improved during the entire interventional procedure (21.1±11.2 vs. 12.8±5.9 frames; p=0.015). Myocardial blush grade, which overall improved during PCI (p<0.001), tended to show greater improvement in patients in whom thrombus aspiration could be achieved (1.6±0.9 vs. 0.7±0.5; p=0.06). Conclusions. Preliminary evidence suggests that manual thrombus aspiration may occasionally be considered in selected patients without acute myocardial infarction but with angiographic evidence of lesion-site thrombus. Nevertheless, prospective studies are required to clearly define the role of this approach in clinical practice. (Neth Heart J 2010;18:423-9.).

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.

Impact of thrombus aspiration use and direct stenting on final myocardial blush score in patients presenting with ST-elevation myocardial infarction

BACKGROUND

Many studies have reported that low final thrombolysis in myocardial infarction (TIMI) flow and/or myocardial blush grade (MBG) are independent predictors of mortality in patients with ST-elevation myocardial infarction (STEMI). In addition, distal coronary embolization is a major pitfall of conventional percutaneous coronary intervention (PCI) in such a context.

AIM

This study aimed to assess the impact of thrombus aspiration (TA) use before primary PCI on final myocardial reperfusion in patients presenting with STEMI.

METHODS

From January to December 2006, 100 patients presenting with STEMI in our catheterization laboratory were considered for the present study. During this time period, 50 patients underwent TA before primary PCI for treatment of STEMI and were then matched 1:1 to 50 controls who underwent conventional primary PCI for treatment of STEMI without TA. Patients of the control group were chosen after matching on age+/-3 years, sex, history of diabetes, and distribution of the infarct related coronary artery during the same period.

RESULTS

Baseline clinical characteristics, initial TIMI flow and initial MBG of both groups were similar. There was a trend for a better final TIMI flow in the group with TA and the final MBG was significantly improved in the group with TA compared to the group without TA: final MBG of two or three in 70% versus 30% of the cases (P=.001). In addition, direct stenting was significantly more often used in the TA group (92% versus 64%, P=.001). There were four patients with evident distal embolizations in the group without TA and none in the group with TA.

CONCLUSION

TA use before primary PCI for STEMI treatment resulted in improved final myocardial reperfusion. Of importance, TA use may have led to a better choice of the stent size and more frequent direct stenting. This benefit may directly improve patient outcomes.

Multicentre experience with MGuard net protective stent in ST-elevation myocardial infarction: safety, feasibility, and impact on myocardial reperfusion

OBJECTIVE

To report, for the first time, angiographic and ECG results as well as in-hospital and 1-month clinical follow-up, after MGuard net protective stent (Inspire-MD, Tel-Aviv, Israel-MGS) implantation in consecutive, not randomized, STEMI patients undergoing primary or rescue PCI.

BACKGROUND

Distal embolization may decrease coronary and myocardial reperfusion after percutaneous coronary intervention (PCI), in ST-elevation myocardial infarction (STEMI) setting.

METHODS

One-hundred consecutive patients underwent PCI, with MGS deployment for STEMI, in five different high-volume PCI centres. Sixteen patients presented cardiogenic shock at admission.

RESULTS

All patients underwent successful procedures: mean TIMI flow grade and mean corrected TIMI frame count-cTFC(n)-improved from baseline values to 2.85 +/- 0.40 and to 17.20 +/- 10.51, respectively, with a mean difference in cTFC(n) between baseline and postprocedure of 46.88 +/- 31.86. High-myocardial blush grade (90% MBG 3; 10% MBG 2) was also achieved in all patients. Sixty minutes post-PCI, a high rate (90%) of complete (>or=70%) ST-segment resolution was achieved. At in-hospital follow-up, seven deaths occurred: noteworthy, 5 of 16 patients with cardiogenic shock at admission died. After hospital discharge, no Major Adverse Cardiac Events have been reported up to 30-day follow-up.

CONCLUSIONS

MGS might represent a safe and feasible option for PCI in STEMI patients, providing high perfusional and ECG improvement. Further randomized trials comparing this strategy with the conventional one are needed in the near future to assess the impact on clinical practice of this strategy.

Microvascular obstruction: underlying pathophysiology and clinical diagnosis

Successful restoration of epicardial coronary artery patency after prolonged occlusion might result in microvascular obstruction (MVO) and is observed both experimentally as well as clinically. In reperfused myocardium, myocytes appear edematous and swollen from osmotic overload. Endothelial cell changes usually accompany the alterations seen in myocytes but lag behind myocardial cell injury. Endothelial cells become voluminous, with large intraluminal endothelial protrusions into the vascular lumen, and together with swollen surrounding myocytes occlude capillaries. The infiltration and activation of neutrophils and platelets and the deposition of fibrin also play an important role in reperfusion-induced microvascular damage and obstruction. In addition to these ischemia-reperfusion-related events, coronary microembolization of atherosclerotic debris after percutaneous coronary intervention is responsible for a substantial part of clinically observed MVO. Microvascular flow after reperfusion is spatially and temporally complex. Regions of hyperemia, impaired vasodilatory flow reserve and very low flow coexist and these perfusion patterns vary over time as a result of reperfusion injury. The MVO first appears centrally in the infarct core extending toward the epicardium over time. Accurate detection of MVO is crucial, because it is independently associated with adverse ventricular remodeling and patient prognosis. Several techniques (coronary angiography, myocardial contrast echocardiography, cardiovascular magnetic resonance imaging, electrocardiography) measuring slightly different biological and functional parameters are used clinically and experimentally. Currently there is no consensus as to how and when MVO should be evaluated after acute myocardial infarction.

Adjunctive Pharmacologic Agents and Mechanical Devices in Primary Percutaneous Coronary Intervention

Primary percutaneous coronary intervention (PPCI) has been shown to be superior to thrombolysis in patients presenting with ST-segment elevation acute myocardial infarction (STEMI) in reducing death, stroke and re-infarction. However, bleeding and thrombotic complications can occur despite successful PPCI and slow flow/no-reflow or poor microvascular reperfusion can occur in a significant minority despite a technically successful procedure. Bleeding or need for peri-procedural transfusion has been shown to increase short- and long-term mortality. Newer anticoagulants appear to reduce the bleeding risk and improve overall clinical outcomes. A novel combination of antiplatelet agents also appears to further improve the outcomes after PPCI. Although PPCI can achieve high rates of epicardial artery patency, some patients experience suboptimal microvascular perfusion, which affects long-term prognosis. Several pharmacologic agents have been shown to improve microvascular perfusion and left ventricular function, although none impacts on clinical outcomes. Of the mechanical devices available to reduce distal embolisation, the simple aspiration catheter holds the most promise in reducing clinical adverse events. Additional research and well designed studies are needed to further enhance the outcomes after PPCI. Key words: Anticoagulant, Antiplatelet agents, Distal protection devices, Myocardial infarction, Pharmacotherapy, Primary angioplasty, Thrombectomy

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.

[Thrombectomy in the acute myocardial infarction: A success in the fight against incomplete myocardial perfusion]

Currently, the preferred treatment of persistent ST-segment elevation acute myocardial infarction is primary angioplasty. After successful primary angioplasty, up to 30% of patients develop left ventricular dilation and heart failure, as a result of incomplete microvascular reperfusion. The pathophysiology of the microvascular dysfunction in the setting of primary angioplasty is complex and not completely known. Distal embolization of necrotic and thrombotic material acts as a mayor factor. No treatment has so far demonstrated proven efficacy in this scenario. However, several prophylactic measures have been identified. Among them, the rheolytic trombectomy offers interesting benefits both in surrogate and clinical outcome variables.

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.

Prophylactic use of manual thrombectomy in ST-segment elevation myocardial infarction

OBJECTIVE

We sought to evaluate the effects of manual thrombectomy on myocardial reperfusion performed during percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

Complete reperfusion after primary PCI is compromised by the presence of intraluminal thrombus. Thus effective and safe extraction of thrombus in a timely fashion is important for successful reperfusion.

METHODS

Thirty-two patients (age 51+/-12 years, males 78%) with STEMI and angiographic evidence of intraluminal thrombus underwent thrombectomy during an 18-month period. Thrombectomy was performed after the presence of thrombus was confirmed angiographically by the operator either before or after primary angioplasty. Thrombectomy was performed using the 6F Export Aspiration Catheter (Medtronic Corporation, Santa Rosa, CA, USA). Myocardial reperfusion using Thrombolysis in Myocardial Infarction (TIMI) flow and myocardial blush grade was assessed by two independent observers.

RESULTS

The infarct-related artery was left anterior descending (59%), right coronary artery (19%), saphenous venous graft (19%), or left circumflex artery (3%). The coronary lesion was Type B in 62% and Type C in 37% patients, with an average length of 18.2+4.6 mm and reference vessel diameter of 3.2+/-0.4 mm. The preprocedural TIMI flow was 0 in 62%, 1 in 12%, 2 in 22%, and 3 in 3% of patients. The postprocedural TIMI flow was 0 in 3%, 1 in 6%, 2 in 25%, and 3 in 56% of patients. The postprocedural myocardial blush grade was 0 in 6%, 1 in 9%, 2 in 35%, and 3 in 48% of patients. The in-hospital mortality was 0 and the 30-day mortality was 3%.

CONCLUSION

Manual thrombectomy using an Export catheter is safe and effective in establishing myocardial reperfusion after STEMI.

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

Impact of thrombus aspiration on myocardial tissue reperfusion and left ventricular functional recovery and remodeling after primary angioplasty

BACKGROUND

Failure to achieve myocardial reperfusion often occurs during percutaneous coronary intervention (PCI) in patients with myocardial infarction with ST-segment elevation. We hypothesized that manual thrombus aspiration during primary PCI would favorably influence tissue-level myocardial perfusion and left ventricular (LV) functional recovery and remodeling.

METHODS AND RESULTS

We prospectively randomized 111 patients with ST-segment elevation myocardial infarction to either standard or thrombus-aspiration PCI. Primary end point of the study was postprocedural incidence of ST-segment resolution >or=70%. Secondary end points included Thrombolysis in Myocardial Infarction (TIMI) myocardial perfusion grade >or=2, the combination of TIMI myocardial perfusion grade >or=2 and ST-segment resolution >or=70%, post-PCI TIMI grade 3 flow, corrected TIMI frame count, myocardial contrast echocardiography score index, the absence of persistent ST-segment deviation, and time course of wall-motion score index, LV ejection fraction, and LV volume in the 2 groups. The incidence of ST-segment resolution >or=70% was 71% and 39% in the thrombus-aspiration and standard PCI groups, respectively (odds ratio, 3.7; 95% CI, 1.7 to 8.3; P=0.001). TIMI myocardial perfusion grade >or=2 was attained in 93% in the thrombus-aspiration group compared with 71% in the standard PCI group (P=0.006). The percentage of patients with ST-segment resolution >or=70% and TIMI myocardial perfusion grade >or=2 was significantly greater in the thrombus-aspiration group compared with the standard PCI group (69% versus 36%, P=0.0006). Myocardial contrast echocardiography score index was significantly higher in the thrombus-aspiration group compared with the standard PCI group (0.86+/-0.20 versus 0.65+/-0.31; P<0.0001). A significantly greater improvement in LV ejection fraction and in wall-motion score index from baseline to 6-month follow-up was observed in the thrombus-aspiration group compared with the standard PCI group (LV ejection fraction from 48+/-6% to 55+/-6% versus 48.7+/-7% to 49+/-8%, P<0.0001; wall-motion score index from 1.59+/-0.13 to 1.31+/-0.19 versus 1.64+/-0.20 to 1.51+/-0.26, P=0.008). Twelve patients (11%) developed LV remodeling at 6 months, 2 (4%) in the thrombus-aspiration group and 10 (18%) in the standard PCI group (P=0.02).

CONCLUSIONS

Manual thrombus aspiration in the setting of primary PCI improves myocardial tissue-level perfusion as well as LV functional recovery and remodeling.

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.

Upfront thrombus aspiration in primary coronary intervention for patients with ST-segment elevation acute myocardial infarction: report of the VAMPIRE (VAcuuM asPIration thrombus REmoval) trial

OBJECTIVES

This study evaluated safety and efficacy of upfront thrombus aspiration during primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

Distal embolization during primary PCI results in reduced myocardial perfusion and poor clinical outcomes.

METHODS

The VAMPIRE (VAcuuM asPIration thrombus REmoval) study was a prospective, randomized, controlled multicenter trial conducted in 23 institutions. Patients (N = 355) presenting within 24 h of STEMI symptoms onset were randomized to primary PCI with (n = 180) or without (n = 175) upfront thrombus aspiration using Nipro's TransVascular Aspiration Catheter (Osaka, Japan).

RESULTS

The TransVascular Aspiration Catheter reached the lesion in 100% of cases. It successfully crossed the target obstruction in 86% without any delay in procedure time or time to reperfusion; whereas macroscopic thrombi were removed in 75% of the cases. Procedure success was similar between groups (98.9% vs. 98.3%). There was a trend toward lower incidence of slow or no reflow (primary end point-defined as a Thrombolysis In Myocardial Infarction flow grade <3) in patients treated with aspiration versus conventional primary PCI (12.4% vs. 19.4%, p = 0.07). Rate of myocardial blush grade 3 was higher in the aspiration group (46.0% vs. 20.5%, p < 0.001). Aspiration was most effective in patients presenting after 6 h of symptoms onset (slow flow rate: 8.1% vs. 37.6%, p = 0.01).

CONCLUSIONS

This study suggested the safety of primary PCI with upfront thrombectomy using a novel device in patients with STEMI. The study showed a trend toward improved myocardial perfusion and lower clinical events in patients treated with aspiration. Patients presenting late after STEMI appear to benefit the most from thrombectomy.

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.

Role of thrombectomy in acute myocardial infarction

Acute ST elevation myocardial infarction results from atherosclerotic plaque rupture with subsequent thrombus formation, leading to complete or near complete occlusion of an epicardial coronary artery. Minimization of the mechanical obstruction from this thrombus remains the main goal of therapy in ST elevation myocardial infarction. Primary percutaneous coronary intervention for an ST elevation myocardial infarction appears to be the preferred mode of revascularization over thrombolytic therapy if the door-to-balloon time target of 90 min is achievable. The idea of reducing the thrombus burden with the use of devices as an adjunct to percutaneous coronary intervention is an attractive one. Several thrombectomy devices have been studied in randomized clinical trials, but no definitive conclusions have emerged, owing to conflicting results and variable clinical end points. This article intends to shed further light on the potential role of thrombectomy in the treatment of acute myocardial infarction.

Effect of thrombus aspiration on infarct size and left ventricular function in high-risk patients with acute myocardial infarction treated by percutaneous coronary intervention. Results of a prospective controlled pilot study

BACKGROUND

Thrombus aspiration devices have been shown to improve reperfusion criteria and to reduce distal embolization in patients treated by percutaneous coronary interventions (PCI) in the acute phase of ST-elevation myocardial infarction (STEMI). There are, however, little data about their efficacy in the reduction of infarct size.

METHODS

We sought to assess in a prospective randomized trial the impact of thrombus aspiration on infarct size and severity and on left ventricular function in high-risk patients with a first STEMI. The primary end point was scintigraphic infarct size, and secondary end points were infarct severity and regional and global left ventricular function. Forty-four patients with completely occluded (Thrombolysis in Myocardial Infarction flow 0-1) proximal segments of infarct-related artery were randomly assigned to thrombus aspiration group with the Export catheter (n = 20) (Medtronic, Inc, Minneapolis, MN) or PCI-only group. A rest Tc-99-mibi gated single-photon emission computed tomographic and contrast-enhanced magnetic resonance imaging were performed 6 +/- 2 days later.

RESULTS

Infarct size was comparable in patients in the thrombus aspiration group and PCI-only group (30.6% +/- 15.8% vs 28.5% +/- 17.9% of the left ventricle, P = .7) as was infarct severity in infarct-related artery territory (55% +/- 12% vs 55% +/- 14%, P = .9). Transmurality score as assessed by magnetic resonance imaging was similar in both groups (2.03 +/- 1.05 vs 2.16 +/- 1.21, P = .7). There was no impact of thrombus aspiration on other secondary end points.

CONCLUSION

In our study, thrombus aspiration with the Export catheter performed as adjunctive therapy in high-risk patients with total occlusion of the proximal part of major coronary arteries does not decrease infarct size or severity and has no effect on left ventricular regional and global function.

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

OBJECTIVES

The purpose of this study was to evaluate the impact on myocardial perfusion and infarct size as assessed by contrast-enhanced magnetic resonance imaging (CE-MRI) of a manual thrombectomy device, Export Medtronic (EM) (Medtronic Inc., Minneapolis, Minnesota), as adjunctive therapy in primary percutaneous coronary intervention (PPCI) in a subset of patients with anterior ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

PPCI may cause thrombus dislodgment, leading to microvascular damage.

METHODS

One hundred seventy-five STEMI patients were randomly assigned to standard percutaneous coronary intervention (PCI) (n = 87) or EM-PCI (n = 88). The primary end points were the occurrence of myocardial blush grade > or =2 and the rate of 90-min ST-segment resolution >70%. The CE-MRI substudy was performed in 75 patients with anterior STEMI to assess microvascular obstruction and infarct size.

RESULTS

Myocardial blush grade > or =2 and ST-segment resolution occurred more frequently in the EM-PCI group (88% vs. 60%, p = 0.001; and 64% vs. 39%, p = 0.001). In the acute phase, microvascular obstruction extent was significantly lower in the EM-PCI group and at 3 months, infarct size was significantly reduced only in the EM-PCI group. A lower incidence of cardiac death in the EM-PCI group (4.6% vs. 0%, log-rank test p = 0.02) was observed at 9 months.

CONCLUSIONS

Thrombectomy prevents thrombus embolization and preserves microvascular integrity reducing infarct size, and it therefore represents an useful adjunctive therapy in PPCI.

Incidence and clinical consequences of distal embolization on the coronary angiogram after percutaneous coronary intervention for ST-elevation myocardial infarction

AIMS

We investigated the incidence and sequelae of angiographically visible distal embolization (AVDE) after primary percutaneous coronary intervention (PCI) in ST-elevation myocardial infarction patients treated with aspirin, heparin, clopidogrel, and glycoprotein-IIb/IIIa inhibitors.

METHODS AND RESULTS

As part of TAPAS, AVDE was a predefined secondary endpoint. We compared angiographic and clinical characteristics, and outcomes of patients with and without AVDE after PCI. AVDE was present on 6.3% of 883 post-procedural angiograms. Angiographically visible distal embolization was associated with significantly worse outcomes, as expressed by lower myocardial blush grade, impaired ST-segment resolution, and higher enzyme levels (all P </= 0.001). Mortality 1 year after PCI was 4 of 56 (7.1%) in patients with AVDE and 43 of 827 (5.2%) in patients without AVDE (P= ns), re-infarction occurred in 5 of 56 (8.9%), and 25 of 827 (3.0%) patients (P = 0.018). The thrombus aspirate more often contained erythrocytes in patients with AVDE than in patients without AVDE (50.0% vs. 15.7%, P < 0.001), and the size of the aspirated thrombus was larger in patients with AVDE (P = 0.002).

CONCLUSION

In patients with triple anti-platelet therapy, the incidence of AVDE after PCI is low, compared with previous reports. Nevertheless, AVDE is associated with impaired myocardial reperfusion and poor outcome. Thrombus composition and size are related to AVDE after PCI.

Current role of emboli protection devices in percutaneous coronary and vascular interventions

After the observation that distal embolization is a frequent complication of coronary and vascular interventions, mechanical emboli protection devices (EPD) have been developed and tested in different vascular territories. The most frequently used device type incorporates a guidewire with a filter that is placed distal to the target lesion, unfolded, and then retrieved at the end of the procedure. Alternative approaches are based on transient flow obstruction using proximal or distal balloon occlusion. The procedure is then performed under flow reversal or flow arrest and the blood column is evacuated prior to restoration of flow. The efficacy of EPD in reducing major adverse cardiac events among patients undergoing percutaneous intervention of aortocoronary bypass grafts has been demonstrated in a randomized trial. In the acute myocardial infarction setting, EPD failed to improve outcomes. Although randomized data in carotid artery stenting are lacking, a broad, but not unanimous, consensus supports the use of these devices. While a small randomized trial showed disappointing results of emboli protection in renal stenting, no data are available for lower extremity interventions.

Comparison of two visual angiographic perfusion grades in acute myocardial infarction

INTRODUCTION

Prognosis after opening the obstructed coronary artery in acute myocardial infarction (AMI) is influenced by several factors. In routine clinical practice, revascularization is considered to be successful when the restoration of epicardial blood-flow is complete. However, the patent epicardial artery does not always provide functional recovery in the myocardium. There are two visual angiographic grades to assess myocardial perfusion: myocardial blush grade (MBG) and TIMI myocardial perfusion grade (TMP). The aim of our study was to compare these two parameters, how they correlate with short-term indicators of myocardial damage.

PATIENTS AND METHODS

The two visual grades were assessed along with enzymatic infarct size as creatine kinase release (CK), echocardiographic left ventricular ejection fraction (LVEF), and ST-segment resolution (STR) in 62 patients with acute myocardial infarction and successful revascularization.

RESULTS

Better correlation was found with TMP in case of all clinical parameters (CK: R= - 0.687, P<0.001; LVEF: R=0.586, P<0.001; STR: R=0.574, P<0.001). MBG also showed significant correlations with clinical measurements, except for enzymatic infarct size (CK: R=- 0.062, P=0.626; LVEF: R=0.389, P=0.002; STR: R=0.348, P=0.006).

CONCLUSION

Our findings suggest that the clearance of the dye (described by TMP) is more characteristic to myocardial recovery after AMI, than maximal contrast density (described by MBG) in the clinical practice.

Microvascular damage prevention with thrombaspiration during primary percutaneous intervention in acute myocardial infarction

BACKGROUND

Despite rapid and complete recanalization of infarct-related artery with percutaneous coronary intervention, microvascular integrity is not often preserved. Several mechanical devices have been proposed to prevent distal embolization, but the impact of these devices on myocardial perfusion remains controversial.

AIM

The aim of our study was to assess microvascular damage reduction with quantitative myocardial contrast perfusion echocardiography among patients with the first anterior acute myocardial infarction treated with thromboaspiration during percutaneous coronary intervention.

METHODS

Forty-two patients (57.4+/-10 years, 74% males) with first anterior acute myocardial infarction were randomized 1 : 1 to intracoronary thromboaspiration followed by stenting, or to a conventional strategy of stenting alone. Echocardiogram and quantitative myocardial contrast echocardiography were performed 7 days and 1 month later, respectively. Parameter A (reflecting myocardial blood volume), beta (reflecting velocity, myocardial blood flow), and product of A and beta as indicator of myocardial blood flow were analyzed. For each patient mean value of A, beta, and A x beta from all dysfunctional segments was calculated.

RESULTS

The study population was divided into two groups: thromboaspiration (group I, 19 patients) and stenting alone (group II, 23 patients). No difference was observed between the both groups in demographic, clinical, echocardiographic, and angiographic data. Parameter A and A x beta were significantly higher in group I than in group II: 8.58+/-2.54 versus 5.29+/-3.18 dB (P<0.001) and 5.29+/-3.73 versus 2.78+/-3.03 dB/s (P<0.001). Multivariate step-down regression analysis revealed that only thromboaspiration before stenting and lower maximum troponin I have been associated with viability preservation in infarcted region.

CONCLUSION

Thromboaspiration before stenting in patients with the first anterior myocardial infarction improves myocardial perfusion at the tissue level assessed by quantitative myocardial contrast echocardiography.

Impact of pretreatment with clopidogrel on initial patency and outcome in patients treated with primary percutaneous coronary intervention for ST-segment elevation myocardial infarction: a systematic review

BACKGROUND

The main goal of the initial treatment of ST-segment elevation myocardial infarction is prompt reperfusion of the infarct-related artery. The value of pretreatment with clopidogrel before primary percutaneous coronary intervention is currently unclear.

METHODS AND RESULTS

Studies were retrieved through MEDLINE and Cochrane Controlled Trials Register searches over the past 20 years. Two authors independently performed the study selection and data extraction. Randomized controlled studies were included when the research subjects were unselected patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention. Pilot trials, studies that enrolled patients undergoing rescue percutaneous coronary intervention, and studies with angiographic assessment not performed by a core laboratory or 2 blinded investigators were excluded. Thirty-eight treatment groups, including 8429 patients, were included. Initial patency was higher in treatment groups in which patients received pretreatment with clopidogrel (34.3%; 95% confidence interval, 32.9 to 35.8) compared with those in which patients did not receive clopidogrel before initial coronary angiography (25.8%; 95% confidence interval, 24.5 to 27.1). In multivariate-weighted logistic regression analysis, pretreatment with clopidogrel was an independent predictor of early reperfusion (odds ratio, 1.51; 95% confidence interval, 1.31 to 1.74; P<0.0001) and improved clinical outcome.

CONCLUSIONS

Initial patency and clinical outcome were improved in treatment groups that received pretreatment with clopidogrel. These results in patients undergoing primary percutaneous coronary intervention are in line with the experience of pretreatment with clopidogrel in elective patients, non-ST-elevation coronary syndromes, and thrombolytic studies.

Role of adjunctive thrombectomy and embolic protection devices in acute myocardial infarction: a comprehensive meta-analysis of randomized trials

AIMS

Adjunctive thrombectomy and embolic protection devices in acute myocardial infarction have been extensively studied, although outcomes have mainly focused on surrogate markers of reperfusion. Therefore, the effect of adjunctive devices on clinical outcomes is unknown. This study sought to determine whether the use of a thrombectomy or embolic protection device during revascularization for acute myocardial infarction reduces mortality compared with percutaneous coronary intervention (PCI) alone.

METHODS AND RESULTS

The Cochrane and Medline databases were searched for clinical trials that randomized patients with ST-elevation acute myocardial infarction to an adjuvant device prior to PCI compared with PCI alone. Devices were grouped into catheter thrombus aspiration, mechanical thrombectomy, and embolic protection. There were a total of 30 studies with 6415 patients who met our selection criteria. Over a weighted mean follow-up of 5.0 months, the incidence of mortality among all studies was 3.2% for the adjunctive device group vs. 3.7% for PCI alone (relative risk, 0.87; 95% confidence interval, 0.67-1.13). Among thrombus aspiration studies, mortality was 2.7% for the adjunctive device group vs. 4.4% for PCI alone (P = 0.018), for mechanical thrombectomy, mortality was 5.3% for the adjunctive device group vs. 2.8% for PCI alone (P = 0.050), and for embolic protection, mortality was 3.1% for the adjunctive device group vs. 3.4% for PCI alone (P = 0.69).

CONCLUSION

Catheter thrombus aspiration during acute myocardial infarction is beneficial in reducing mortality compared with PCI alone. Mechanical thrombectomy appears to increase mortality, whereas embolic protection appears to have a neutral effect.