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

The Use of Thrombectomy during Primary Percutaneous Coronary Intervention: Resurrecting an Old Concept in Contemporary Practice

Optimal myocardial reperfusion during primary percutaneous coronary intervention (pPCI) is increasingly recognized to be beyond restoring epicardial coronary flow. Both invasive and non-invasive tools have highlighted the limitation of using this metric, and more efforts are focused towards achieving optimal reperfusion at the level of the microcirculation. Recent data highlighted the close relationship between thrombus burden and impaired microcirculation in patients presenting with ST-segment elevation myocardial infarction (STEMI). Moreover, distal embolization was an independent predictor of mortality in patients with STEMI. Likewise, the development of no-reflow phenomenon has been directly linked with worse clinical outcomes. Adjunctive thrombus aspiration during pPCI is intuitively intended to remove atherothrombotic material to mitigate the risk of distal embolization and the no-reflow phenomenon (NRP). However, prior trials on the use of thrombectomy during pPCI did not support its routine use, with comparable clinical endpoints to patients who underwent PCI alone. This article aims to review the existing literature highlighting the limitation on the use of thrombectomy and provide future insights into trials investigating the role of thrombectomy in contemporary pPCI.

Initial experience with a continuous mechanical aspiration system for thrombus removal before percutaneous coronary intervention

OBJECTIVES

Here we investigate the safety and efficacy of a continuous mechanical aspiration system when used before percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS).

BACKGROUND

Historically, trials of routine manual aspiration thrombectomy in ACS patients have reported mixed results. This may be due to the technical limitations of manual aspiration, which suffers from decreasing vacuum power as aspiration is performed.

METHODS

This is a retrospective case series of all patients treated with continuous mechanical aspiration (Indigo CAT RX Aspiration System; Penumbra Inc.) before PCI between August 2017 and July 2020 at five centers in the United States. Data regarding angiographic assessments, procedure, and safety were examined.

RESULTS

Seventy-two patients (mean age 60 ± 12.5 years, 34.7% female) with ST Elevation Myocardial Infarction (STEMI) (80.6%) or Non-ST Elevation Myocardial Infarction (NSTEMI) (19.4%) were included. Target vessels were the right coronary (43.1%), left anterior descending (33.3%), and left circumflex (23.6%). Preprocedure, 94.4% had a high thrombus burden (thrombolysis in myocardial infarction [TIMI] thrombus grade ≥ 3). Median aspiration time was 35 s and median access-to-reperfusion time was 10 min. After CAT RX alone, 86.1% had complete perfusion (TIMI flow grade 3). After the procedure, 94.4% had TIMI thrombus grade <3% and 97.2% had TIMI flow grade 3. There were no cases of ischemic stroke. Cardiovascular mortality at 30 days was 1.4%.

CONCLUSIONS

In our initial experience, aspirating thrombus from ACS patients using the Indigo CAT RX Aspiration System before PCI was safe and effective for reducing thrombus burden and restoring flow.

Aspiration Thrombectomy

Distal embolization of thrombus can lead to impairment of microvascular perfusion, and measures of abnormal microvascular perfusion have been associated with increased mortality and worsened clinical outcomes. Large multicenter randomized controlled trials and multiple meta-analyses have failed to demonstrate an improvement in clinical outcomes with the routine use of manual aspiration thrombectomy, with some studies suggesting an increased incidence of stroke, likely owing to thrombus dislodgement during retrieval leading to cerebral vessel embolization. In patients with high thrombus burden who do not respond to balloon predilation, the use of manual aspiration thrombectomy as a bailout treatment strategy can be considered.

Aspiration thrombectomy in ST-Elevation myocardial infarction: Further insights from a network meta-analysis of randomized trials

Background

The initial enthusiasm for thrombectomy during percutaneous coronary intervention (PCI) of ST-elevation myocardial infarction (STEMI) patients has given way to restraint. There has been some limited interest whether it is beneficial in a few selected subgroups. Hence, we performed a network meta-analysis to compare conventional PCI (cPCI), Aspiration or manual thrombectomy (AT) and Mechanical thrombectomy (McT) for clarification.

Methods

Electronic databases were searched for randomized studies that compared AT, McT, or cPCI. A network meta-analysis was performed and odd’s ratio (OR) with 95% confidence intervals was generated for major adverse cardiac events (MACE), mortality, myocardial infarction (MI), target vessel revascularization (TVR), stent thrombosis (ST), stroke, left ventricular ejection fraction (LVEF), myocardial blush grade (MBG) and ST segment resolution (STR).

Results

A total of 43 randomized trials (n = 26,682) were included. The risk of MACE (OR 0.86 95% CI 0.73–1.00), Mortality (OR 0.85 95% CI 0.73–0.99), MI (OR 0.65, 95% CI: 0.44–0.95) and TVR (OR 0.86, 95% CI: 0.74–1.00) were lower with AT compared to cPCI. The risk of ST and stroke was no different with the use of adjunctive AT. MBG, STR, and LVEF improved with the use of AT while the infarct size was no different in the two groups.

Conclusions

Our comprehensive network meta-analysis suggests conflicting outcomes with AT. While Mortality, MACE, MI seem better, there is a suggestion that, Stroke and ST might be worse. Whether AT can still be pursued in any select cases should be further scrutinized.

Plasmodium spp. mixed infection leading to severe malaria: a systematic review and meta-analysis

Mixed Plasmodium malaria infections can lead to severe malaria. This systematic review and meta-analysis aimed to explore the prevalence of severe mixed Plasmodium malaria infection and to compare it with the prevalence of severe P. falciparum malaria mono-infection across the included studies. Original English-language research articles from PubMed, Scopus, and ISI Web of Science were identified and screened. Articles reporting the number of mixed infections and the number of severe mixed infections were used to determine the main outcome of this study, while the number of P. falciparum infections and the number of severe P. falciparum infections were used to determine the secondary outcome of this study. For the main outcome, the pooled prevalence and 95% confidence interval (CI) of severe mixed infections was analysed using STATA software version 15.0 (Stata Corp, College Station, TX, USA). For the secondary outcome, the rate of severe mixed infections compared to severe P. falciparum infections was analysed using the meta-analysis approach, and summary odds ratios (ORs) and 95% CIs were calculated. Random-effects models were used to produce the summary ORs. The Mantel–Haenszel method and calculated I² were also reported to test whether there was heterogeneity among the included studies. Publication bias was also assessed using funnel plots. The meta-analysis of secondary outcomes was conducted using Review Manager 5.3 software (Cochrane Community). A total of 894,561 malaria patients were reported in all 16 included studies. Overall, a pooled analysis showed that 9% (2,006/35,768, 95% CI 7.0–12.0%) of patients with mixed Plasmodium infection had severe mixed infection. A meta-analysis of 14 studies demonstrated that patients with mixed Plasmodium infection (1,999/35,755) and patients with P. falciparum malaria (9,249/294,397) had an equal risk of developing severe malaria (OR 0.93, 95% CI 0.59–1.44). Both mixed infection and P. falciparum mono-infection showed a similar trend of complications in which severe anaemia, pulmonary failure, and renal impairment were the three most common complications found. However, patients with mixed infection had a higher proportion of severe anaemia and pulmonary complications than those with P. falciparum infection. Moreover, patients with mixed infection had a higher proportion of multiple organ failure than those with P. falciparum mono-infection. Mixed Plasmodium spp. infections were common but often unrecognized or underestimated, leading to severe complications among these malaria patients. Therefore, in routine clinical laboratories, using an accurate combination of diagnostic procedures to identify suspected patients with mixed infections is crucial for therapeutic decisions, prompt treatment, and effective patient management.

Long-term clinical outcomes of thrombus aspiration in STEMI patients undergoing primary percutaneous coronary intervention

BACKGROUND

Clinical trials that evaluated long-term clinical outcomes of thrombus aspiration before primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) have shown different results. Thus, this study was designed to evaluate the long-term clinical outcomes and trends in present usage of thrombosuction in STEMI patients undergoing primary PCI.

METHODS

This was a single-center, retrospective study conducted at a tertiary-care center in India between January 2016 and December 2018. A total of 241 patients with STEMI who underwent primary PCI were differentiated into thrombus aspiration or standard primary PCI group. Primary endpoint was major adverse cardiac events (MACE) at 1-year. The other safety outcome measured at 1-year follow-up was stent thrombosis.

RESULTS

Among 241 patients, 119 patients were included in the thrombus aspiration group and 122 patients were included in the standard primary PCI group. All patients underwent 1-year follow-up. MACE rate was found to be 4.2% and 4.9% in thrombus aspiration and standard primary PCI group (P=0.79), respectively. Death from any cause was found to be higher in thrombus aspiration 7 (5.9%) compared to standard primary PCI group 5 (4.1%). Of which, cardiac death has occurred in 5 (4.2%) patients of thrombus aspiration group and 4 (3.3%) patients of standard primary PCI group (P=0.747). Definite stent thrombosis was observed in 1 (0.8%) patient of both the groups (P=1.00).

CONCLUSION

The study concludes that there was no significant benefit of thrombus aspiration concerning mortality rate or any other clinical outcomes at 1-year in STEMI patients.

Clinical and procedural predictors of suboptimal myocardial reperfusion in primary percutaneous coronary intervention

Background

Suboptimal myocardial perfusion in primary PCI is associated with increased infarct size, left ventricular (LV) dysfunction and higher mortality rates as compared as those with optimal myocardial perfusion. We identified clinical and procedural predictors of suboptimal myocardial reperfusion as judged by myocardial plush grade (MBG) in primary PCI.

Methods and Results

100 patients with acute STEMI who underwent primary PCI were prospectively subjected to clinical, ECG, laboratory and angiographic evaluation. Patients were classified into: Optimal myocardial reperfusion group: (n=73) who had final MBG=3. Suboptimal myocardial reperfusion group: (n=27) who had persistent final MBG ≤ 2. Suboptimal myocardial reperfusion group had statistically significant little history of angina prior to MI 5 (18.5%) vs 44 (60.3%), little current aspirin intake 6(22%) vs 38 (52% ), increased blood sugar on admission (240 ± 101 mg/dl vs 171 ± 72 mg/dl), increased total leucocytic count on admission (12.1 ± 3.6 vs 10.2 ± 3.3) 103/mm3, longer reperfusion time (6.1 ± 2.8 vs 4.3 ± 2.1 h ), higher thrombus burden 12 (44.4 % ) vs 13 (17.8 %), higher predilatation pressure (16 ± 2.3 vs 14 ± 1.8 ATM), repeated balloon inflation during predilatation 24 (92.3 % ) vs 46 (69.7%) as compared optimal myocardial reperfusion group, (P < 0.05 for all).

Conclusion

Longer reperfusion time, repeated balloon inflations, high predilatation pressure> 15 ATM , high thrombus burden, neither history of angina nor aspirin intake prior to AMI, high total leucocytic count > 10103/mm3 and high blood glucose level > 160mg/dl were predictors for persistent suboptimal myocardial reperfusion in primary PCI.

Prognostic value of gasping for short and long outcomes during out-of-hospital cardiac arrest: an updated systematic review and meta-analysis

Objective

We systematically reviewed the literature to investigate whether gasping could predict short and long outcomes in patients with out of hospital cardiac arrest (OHCA).

Methods

PubMed, Embase, and Cochrane Library were searched for observational studies regarding the prognostic effect of gasping on short and long outcomes in adults with OHCA. The primary outcome was return of spontaneous circulation (ROSC). The secondary outcomes were favorable neurological outcome at discharge or at 30 days after cardiac arrest;long term (≥6 months) survival; initial shockable rhythm.The Mantel-Haenszel method with random-effects model was used to calculate pooled relative risks (RRs) and 95% confidence intervals (CIs).

Results

Five studies (six cohorts) were included in the final analysis. In the pooled analysis, gasping was not only associated with a significant increase in ROSC (RR, 1.87; 95% CI, 1.64–2.13; I² = 70%), but also a high likelihood of favorable neurological outcomes (RR, 3.79; 95% CI, 1.86–7.73), long-term survival (RR, 3.46; 95% CI, 1.70–7.07), and initial shockable rhythm (RR, 2.25; 95% CI, 2.05–2.48).

Conclusions

Current evidence indicates that gasping can predict short and long outcomes in patients with OHCA.In addition, gasping is associated with a high likelihood of initial shockable rhythm,which may contribute to positive outcomes.

Outcome of thrombus aspiration in STEMI patients: a propensity score-adjusted study

The use of thrombus aspiration (TA) prior to primary percutaneous coronary intervention (PPCI) has undergone a radical change in intervention guidelines. The clinical implications, however, are still under scrutiny. This study investigated the clinical effects and outcome of TA before PPCI in patients with ST-segment elevation myocardial infarction (STEMI). Overall 1027 patients with STEMI were analyzed in this retrospective, propensity score-adjusted, multicenter study. The primary endpoints were in-hospital and long-term mortality. There were 418 patients in the TA group and 609 in the conventional PPCI group. The in-hospital mortality rate was significantly higher in the TA group (8.7 vs. 5.0%; P = 0.03). During long-term follow-up [median follow-up duration 689 days (IQR 405-959)] the mortality rates were similar (TA 14.3%, conventional PPCI 15.0%; P = 0.85). Survival analysis for the complete observation period revealed no significant benefit of TA [hazard ratio (HR) 1.12; 97.5% CI 0.90-0.71; P = 0.63]. There were also no significant differences between the groups in the following secondary endpoints: composite of cardiovascular death and non-fatal reinfarction at discharge (P = 0.39), post-PPCI thrombolysis in myocardial infarction flow-grade-3 (P = 0.14), left ventricular ejection fraction (P = 0.47), and non-fatal reinfarction during follow-up (P = 0.17). Rehospitalization rate (1.82 vs. 10.3%; P < 0.0001) and Canadian Cardiovascular Society (CCS) grading (P = 0.02) during follow-up were significantly lower in the TA group. In our cohort the in-hospital mortality rate was significantly higher for TA patients, but during long-term follow-up the mortality rates did not differ. The incidence of rehospitalization and CCS grading were lower in the TA-treated patients.

Efficacy and safety of thrombus aspiration in ST-segment elevation myocardial infarction: an updated systematic review and meta-analysis of randomised clinical trials

BACKGROUND:

The role of thrombus aspiration plus primary percutaneous coronary intervention in ST-segment elevation myocardial infarction remains controversial.

METHODS:

We performed a meta-analysis of 25 randomised controlled trials in which 21,740 ST-segment elevation myocardial infarction patients were randomly assigned to thrombus aspiration plus primary percutaneous coronary intervention or primary percutaneous coronary intervention. Study endpoints were: death, myocardial infarction, stent thrombosis and stroke.

RESULTS:

On pooled analysis, the risk of death (4.3% vs. 4.8%, odds ratio (OR) 0.90, 95% confidence interval (CI) 0.79-1.03; P=0.123), myocardial infarction (2.4% vs. 2.5%, OR 0.95, 95% CI 0.80-1.13; P=0.57) and stent thrombosis (1.3% vs. 1.6%, OR 0.80, 95% CI 0.63-1.01; P=0.066) was similar between thrombus aspiration plus primary percutaneous coronary intervention and primary percutaneous coronary intervention. The risk of stroke was higher in the thrombus aspiration plus primary percutaneous coronary intervention than the primary percutaneous coronary intervention group (0.84% vs. 0.59%, OR 1.401, 95% CI 1.004-1.954; P=0.047). However, on sensitivity analysis after removing the TOTAL trial, thrombus aspiration plus primary percutaneous coronary intervention was not associated with an increased risk of stroke (OR 1.01, 95% CI 0.58-1.78). The weak association between thrombus aspiration and stroke was also confirmed by the fact that the lower bound of the 95% CI was slightly below unity after removing either the study by Kaltoft or the ITTI trial. There was no interaction between the main study results and follow-up, evidence of coronary thrombus, or study sample size.

CONCLUSIONS:

In patients with ST-segment elevation myocardial infarction, thrombus aspiration plus primary percutaneous coronary intervention does not reduce the risk of death, myocardial infarction or stent thrombosis. Thrombus aspiration plus primary percutaneous coronary intervention is associated with an increased risk of stroke; however, this latter finding appears weak.

Thrombus Aspiration for ST-Segment-Elevation Myocardial Infarction in Modern Era: Still an Issue of Debate?

The role of manual thrombus aspiration (TA) during primary percutaneous coronary intervention (PPCI) for acute ST-segment-elevation myocardial infarction has been a matter of intense research and debate now. Although recent randomized controlled clinical trials (notably TASTE [Thrombus Aspiration in ST-Elevation Myocardial Infarction in Scandinavia] and TOTAL [Trial of Routine Aspiration Thrombectomy With PCI Versus PCI Alone in Patients With STEMI]) do not supply evidence supporting the routine use of TA in patients with ST-segment-elevation myocardial infarction, manual TA remains a therapeutic option for interventional cardiologists when treating patients with substantial thrombus burden during PPCI. It remains unknown whether patients might actually benefit from TA applied in a more selective manner depending on the thrombus burden during PPCI, instead of routine application. In this review, we summarize current knowledge on the instruments used in the TA procedure, positive as well as negative clinical effects of TA during PPCI, and analyze the potential reasons for observed effects, in an effort to help the clinical decision making by physicians for the use of TA in individual ST-segment-elevation myocardial infarction patients during PPCI.

The role of manual thrombectomy in cardiovascular outcome among patients with total cutoff vessel myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND

The applicability of manual aspiration thrombectomy in patients with ST-segment elevation myocardial infarction (STEMI) has been a challenging issue. This study aimed to compare the impact of additive manual thrombectomy on patients with myocardial infarction (MI) and total cutoff vessel with standard primary percutaneous coronary intervention (PPCI) with bailout thrombectomy.

METHODS

In this case-control study, 181 patients with acute STEMI were enrolled who referred to Chamran Hospital (Isfahan, Iran) between August to December 2014. The culprit lesion was treated with routine PPCI with bailout thrombectomy (111 patients) and routine primary thrombectomy then percutaneous coronary intervention [(PCI), 70 patients] during hospitalization and one month after discharge. Patients in the case group received manual thrombectomy before PPCI and patients in the control group received standard PPCI with bailout thrombectomy. Patients were followed during the study procedure, post-hospitalization and one month later for cardiovascular outcomes including death, recurrent MI, stroke, major bleeding, post PCI arrhythmia, no reflow, thrombolysis in myocardial infarction (TIMI)-flow and TIMI myocardial blush grade (TMBG), which were assessed and recorded.

RESULTS

Myocardial perfusion and angiographic outcomes had no significant differences in the two groups (P = 0.730). There was also no significant difference in no reflow prevalence between the two groups (P > 0.990). There were no significant differences for primary outcomes such as death, stroke, major bleeding and arrhythmia between the two groups (P < 0.050). In particular, outcomes were the same for both groups during hospitalization period and one month after discharge. Mortality rate during hospitalization was 5.7% for the control group and 4.5% for the case group (P = 0.730). However, one-month mortality rate was quite similar in both groups.

CONCLUSION

This study showed there is no significant difference in cardiovascular outcomes such as death, stroke, bleeding, arrhythmia, target vessel revascularization, and distal embolization during hospitalization and one month after discharge in patients with acute MI and total cutoff of the involved vessel, who underwent PPCI with and without primary Export® aspiration catheter direct thrombosuction.

A review of strategies for infarct size reduction during acute myocardial infarction

Advances in medical and interventional therapy over the last few decades have revolutionized the treatment of acute myocardial infarction. Despite the ability to restore epicardial coronary artery patency promptly through percutaneous coronary intervention, tissue level damage may continue. The reported 30-day mortality after all acute coronary syndromes is 2 to 3%, and around 5% following myocardial infarction. Post-infarct complications such as heart failure continue to be a major contributor to cardiovascular morbidity and mortality. Inadequate microvascular reperfusion leads to worse clinical outcomes and potentially strategies to reduce infarct size during periods of ischemia-reperfusion can improve outcomes. Many strategies have been tested, but no single strategy alone has shown a consistent result or benefit in large scale randomised clinical trials. Herein, we review the historical efforts, current strategies, and potential novel concepts that may improve myocardial protection and reduce infarct size.

An evaluation of pre-hospital emergency medical systems for suspected ST-elevation myocardial infarction in Colorado

OBJECTIVES

Patients presenting with ST-elevation myocardial infarction (STEMI) benefit from rapid cardiac reperfusion therapy. Emergency medical service (EMS) agencies can improve patient outcomes by calling STEMI alerts to the receiving facility. The aim of this study was to evaluate the use of pre-hospital activation systems for suspected ST-elevation myocardial infarctions (STEMI) throughout Colorado.

METHODS

A cross sectional, survey design was utilized to collect all data from EMS agencies in Colorado. A univariable logistic regression model was used to identify factors predictive of an agency reporting that they utilize a STEMI activation protocol.

RESULTS

84.5% [95% CI: 78.3 to 90.7%] of agencies included indicate that they utilize a STEMI activation protocol. Based on the logistic regression analysis, the number of EMT employees was significantly associated with whether or not an agency indicates that they utilize a STEMI activation protocol. For every 10% increase in the number of EMTs employed by an EMS agency, there was a 3.0 [95% CI: 1.5 to 6.0, p = 0.0012] fold increase in the odds of the agency indicating they utilize a STEMI activation protocol.

CONCLUSIONS

Our study provides evidence that larger agencies are more likely to utilize a STEMI activation protocol. In areas without a STEMI system of care, improvements in smaller agencies that cover more ground (with longer transport times) should be the focus for protocol implementation. Based on the current prevalence of such training, competency based training in reading ST-elevations on ECG should be considered by EMS agencies.

Effects of the short-term application of pantoprazole combined with aspirin and clopidogrel in the treatment of acute STEMI

The aim of the present study was to determine the effects of the short-term application of pantoprazole on the co-treatment of acute ST-segment elevation myocardial infarction (STEMI) with aspirin and clopidogrel. A total of 207 acute patients showing primary symptoms of STEMI, who received successful emergent percutaneous coronary intervention treatment during hospitalization were randomly divided into two groups. In the test group proton pump inhibitors (PPIs), the patients were treated with a combination of aspirin and clopidogrel and pantoprazole, while those in the control group were treated only with aspirin and clopidogrel. Gastrointestinal bleeding events and major adverse cardiac events (MACEs) were observed in the two groups. Gastrointestinal bleeding events of the two groups mostly occurred within the first week of hospitalization, although the incidence in the PPIs group was significantly higher than that in the control group (p<0.05). However, no significant difference was observed for the incidence of MACEs between the two groups (p>0.05). In conclusion, the results of the present study have shown that the short-term application of pantoprazole combined with aspirin and clopidogrel does not increase the incidence of MACEs in patients with acute STEMI, reduces the risk of gastrointestinal bleeding, and is thus worth promoting clinically, particularly for high-risk groups.

Aspiration Thrombectomy in Patients Undergoing Primary Angioplasty for ST Elevation Myocardial Infarction: An Updated Meta-Analysis

BACKGROUND

The Trial of Routine Aspiration Thrombectomy with PCI versus PCI alone in patients with STEMI (TOTAL trial) refuted the salutary effect of routine aspiration thrombectomy (AT) in PPCI for patients with ST-elevation myocardial infarction (STEMI).

OBJECTIVES

We performed an updated meta-analysis to assess clinical outcomes with AT prior to PPCI compared with conventional PPCI alone including the additional trial data.

METHODS AND RESULTS

Clinical trials (n = 20) that randomized patients (n = 21,281) with STEMI between Routine AT (n = 10,619) and PPCI (n = 10,662) were pooled. There was no difference in all-cause mortality between the 2 groups (RR: 0.89, 95%CI: 0.78-1.01, P = 0.08). Stratifying by follow up at 1-month (RR: 0.87, 95%CI: 0.69-1.10, P = 0.25), up to 6 months (RR: 0.91, 95%CI: 0.74-1.13, P = 0.39 and beyond 6 months (RR: 0.88, 95%CI: 0.74-1.05, P = 0.16) yielded similar results. There was a statistically significant increase risk of stoke rate in the AT arm (RR: 1.51, 95%CI: 1.01-2.25, P = 0.04). The 2 groups were similar with regards to target vessel revascularization (0.94, 95%CI: 0.83-1.06, P = 0.28) recurrent MI (RR: 0.96, 95%CI: 0.80-1.16, P = 0.68, MACE events (RR: 0.91 95%CI: 0.81-1.02, P = 0.11), early (0.59, 95%CI: 0.23-1.50, P = 0.27) and late (RR: 0.91, 95%CI: 0.69-1.18, P = 0.47) stent thrombosis and net clinical benefit (RR 0.99, 95%CI: 0.91-1.07, P = 0.76).

CONCLUSION

Routine AT prior to PPCI in STEMI is associated with higher risk of stroke. There is no statistical difference in clinical outcome parameters of mortality, major adverse cardiac events, target vessel revascularization, stent thrombosis, and net clinical benefit between AT and PCI alone.

No reflow phenomenon in percutaneous coronary interventions in ST-segment elevation myocardial infarction

Percutaneous coronary intervention (PCI) is effective in opening the infarct related artery and restoring thrombolysis in myocardial infarction flow 3 (TIMI-flow 3) in large majority of ST-elevation myocardial infarction (STEMI). However there remain a small but significant proportion of patients, who continue to manifest diminished myocardial reperfusion despite successful opening of the obstructed epicardial artery. This phenomenon is called no-reflow. Clinically it manifests with recurrence of chest pain and dyspnea and may progress to cardiogenic shock, cardiac arrest, serious arrhythmias and acute heart failure. No reflow is regarded as independent predictor of death or recurrent myocardial infarction. No reflow is a multi-factorial phenomenon. However micro embolization of atherothrombotic debris during PCI remains the principal mechanism responsible for microvascular obstruction. This review summarizes the pathogenesis, diagnostic methods and the results of various recent randomized trials and studies on the prevention and management of no-reflow.

Early Administration of Intracoronary Nitroprusside Compared with Thrombus Aspiration in Myocardial Perfusion for Acute Myocardial Infarction: A 3-Year Clinical Follow-Up Study

BACKGROUND

Intracoronary nitroprusside and thrombus aspiration have been demonstrated to improve myocardial perfusion during percutaneous coronary interventions (PCI) for ST-segment elevation acute myocardial infarction (STEMI) However, no long-term clinical studies have been performed comparing these approaches.

METHODS

A single medical center retrospective study was conducted to evaluate the effects of intracoronary nitroprusside administration before slow/no-reflow phenomena versus thrombus aspiration during primary PCI. Forty-three consecutive patients with STEMI were enrolled in the intracoronary nitroprusside treatment group. One hundred twenty-four consecutive STEMI patients who received thrombus aspiration were enrolled; ninety-seven consecutive STEMI patients who did not receive either thrombus aspiration or intracoronary nitroprusside treatment were enrolled and served as control subjects. Patients with cardiogenic shock, who had received platelet glycoprotein IIb/IIIa inhibitor, or intra-aortic balloon pump insertion were excluded. Thrombolysis in Myocardial Infarction (TIMI) flow grade, corrected TIMI frame count and TIMI myocardial perfusion grade (TMPG) were assessed prior to and following PCI by two independent cardiologists blinded to the procedures. The rate of major adverse cardiac events (MACE) at 30 days, 1 year, and 3 years after study enrollment as a composite of recurrent myocardial infarction, target-vessel revascularization, and cardiac death were recorded.

RESULTS

The control group had a significantly lower pre-PCI TIMI flow (≤ 1; 49.5% vs. 69.8% vs. 77.4%; p = < 0.001) compared with the nitroprusside and thrombus aspiration groups. The thrombus aspiration group had a significantly higher pre-PCI thrombus score (> 4; 98.4% vs. 88.4% vs. 74.3%; p = < 0.001) and post-PCI TMPG (3; 39.5% vs. 16.3% vs. 20.6%; p = 0.001) compared with the nitroprusside and control groups. No significant differences were noted in the post-PCI thrombus score, 30-day, 1-year and 3-year MACE rate, and Kaplan-Meier curve among 3 groups of patients.

CONCLUSIONS

Although thrombus aspiration provided improved TMPG compared with early administration of intracoronary nitroprusside and neither of both during primary PCI, it did not have a significant impact on 30-day, 1-year and 3-year MACE rate.

KEY WORDS

Acute myocardial infarction; Intracoronary nitroprusside; Thrombus aspiration.

Is Aspiration Thrombectomy Beneficial in Patients Undergoing Primary Percutaneous Coronary Intervention? Meta-Analysis of Randomized Trials

BACKGROUND

It is unclear whether intravenous glycoprotein IIb/IIIa inhibitors or ischemic time might modify any clinical benefits observed with aspiration thrombectomy before primary percutaneous coronary intervention (PCI) in patients with ST-segment-elevation myocardial infarction.

METHODS AND RESULTS

Electronic databases were searched for trials that randomized ST-segment-elevation myocardial infarction patients to aspiration thrombectomy before PCI versus conventional PCI. Summary estimates were constructed using a DerSimonian-Laird model. Seventeen trials with 20 960 patients were available for analysis. When compared with conventional PCI, aspiration thrombectomy was not associated with a significant reduction in the risk of mortality 2.8% versus 3.2% (risk ratio [RR], 0.89; 95% confidence interval [CI], 0.76-1.04; P=0.13), reinfarction 1.3% versus 1.4% (RR, 0.93; 95% CI, 0.73-1.17; P=0.52), the combined outcome of mortality or reinfarction 4.1% versus 4.6% (RR, 0.90; 95% CI, 0.79-1.02; P=0.11), or stent thrombosis 0.9% versus 1.2% (RR, 0.82; 95% CI, 0.62-1.08; P=0.15). Aspiration thrombectomy was associated with a nonsignificant increase in the risk of stroke 0.6% versus 0.4% (RR, 1.45; 95% CI, 0.96-2.21; P=0.08). Meta-regression analysis did not identify a difference for the log RR of mortality, reinfarction, and the combined outcome of mortality or reinfarction with intravenous glycoprotein IIb/IIIa inhibitors (P=0.17, 0.70, and 0.50, respectively) or with ischemic time (P=0.29, 0.66, and 0.58, respectively).

CONCLUSIONS

Aspiration thrombectomy before primary PCI is not associated with any benefit on clinical end points and might increase the risk of stroke. Concomitant administration of intravenous glycoprotein IIb/IIIa inhibitors and ischemic time did not seem to influence any potential benefits observed with aspiration thrombectomy.

The Rise and Fall of Routine Manual Thrombectomy for ST-Elevation Myocardial Infarction

Manual thrombectomy (MT) with an aspiration catheter is frequently used in primary percutaneous coronary intervention (PPCI) for acute myocardial infarction with ST-segment elevation (STEMI). It is used to reduce the thrombus burden and the risk of no-reflow in the infarct related artery. This article summarises a chronological overview of the available evidence for its routine use in PPCI. An early series of small randomised controlled trials (RCTs) have shown a benefit of PPCI with MT over percutaneous coronary intervention alone, mainly when considering intermediate endpoints reflecting myocardial reperfusion. However, a recent series of large multicentre RCTs failed to corroborate the initial enthusiasm for MT, showing no improved benefit on hard endpoints such as mortality when compared with PPCI without MT. Furthermore, the largest RCT to date raised safety concerns after reporting an increased stroke risk after MT. We review the background, value, and implications of the current evidence before concluding that the routine use of MT in PPCI for STEMI should not be encouraged.

Acute Myocardial Infarction/Thrombectomy

This article focuses on specialized techniques and devices used in the most challenging cases of acute myocardial infarction. Areas where high-quality evidence is either clear or absent are avoided. Controversies in the use of support or thrombectomy devices, the addition of adjunct pharmacology, and the decision to treat nonculprit lesions are discussed. Recent years have seen a shift in guidelines to downgrading the use of assist devices in cardiogenic shock and aspiration thrombectomy, whereas consideration of nonculprit coronary intervention has been revived. These changes come in the wake of a series of large, practice-changing clinical trials.

Comparison of Successful Myocardial Reperfusion and Adverse Events in Patients With ST-Elevation Myocardial Infarction Who Underwent Rescue Percutaneous Coronary Intervention After Failed Fibrinolytic Therapy With Versus Without Manual Coronary Thrombus Aspiration

It has been unclear the impact of manual thrombus aspiration (TA) on procedural outcomes in patients with ST-elevation myocardial infarction (STEMI) who underwent rescue percutaneous coronary intervention (PCI) after failed fibrinolytic therapy in comparison with primary PCI. Our aim was to test the hypothesis that manual TA may improve myocardial reperfusion and clinical outcomes in patients with STEMI who underwent rescue PCI after failed fibrinolytic therapy. From March 2011 to March 2014, 70 patients with STEMI after unsuccessful fibrinolysis were randomized to either rescue PCI with TA (TA group) or without TA (NTA group). Primary end points were rate of myocardial blush grade ≥2 and ST-segment resolution ≥70%. The secondary end point included 30 days follow-up for major adverse cardiac events (MACEs). Baseline clinical and angiographic characteristics were similar in the 2 groups. The TA and NTA groups were compared as follows: myocardial blush grade ≥2, 71% versus 46% (p <0.05); complete ST-segment resolution 71% versus 46% (p <0.05); no reflow 20% versus 49% (p <0.05); procedure time (min) 65.0 ± 38.6 versus 90.1 ± 28.8 (p <0.05); contrast amount (ml) 99.0 ± 45.2 versus 121.2 ± 33.4 (p <0.05); and direct stenting 60% versus 37% (p <0.05). There was a significant reduction of MACE in the TA group, 20% versus 37% (p <0.05). In conclusion, rescue PCI with manual TA leads to better myocardial reperfusion and significant reduction of MACE.

Stroke in the TOTAL trial: a randomized trial of routine thrombectomy vs. percutaneous coronary intervention alone in ST elevation myocardial infarction

AIMS

TOTAL (N = 10 732), a randomized trial of routine manual thrombectomy vs. percutaneous coronary intervention alone in ST elevation myocardial infarction, showed no difference in the primary efficacy outcome but a significant increase in stroke. We sought to understand these findings.

METHODS AND RESULTS

A detailed analysis of stroke timing, stroke severity, and stroke subtype was performed. Strokes were adjudicated by neurologists blinded to treatment assignment. Stroke within 30 days, the primary safety outcome, was increased [33 (0.7%) vs. 16 (0.3%), hazard ratio (HR) 2.06; 95% confidence interval (CI) 1.13-3.75]. The difference in stroke was apparent within 48 h [15 (0.3%) vs. 5 (0.1%), HR 3.00; 95% CI 1.09-8.25]. There was an increase in strokes within 180 days with minor or no disability (Rankin 0-2) [18 (0.4%) vs. 13 (0.3%) HR 1.38; 95% CI 0.68-2.82] and in strokes with major disability or fatal (Rankin 3-6) [35 (0.7%) vs. 13 (0.3%), HR 2.69; 95% CI 1.42-5.08]. Most of the absolute difference was due to an increase in ischaemic strokes within 180 days [37 (0.7%) vs. 21 (0.4%), HR 1.71; 95% CI 1.03-3.00], but there was also an increase in haemorrhagic strokes [10 (0.2%) vs. 2 (0.04%), HR 4.98; 95% CI 1.09-22.7]. Patients that had a stroke had a mortality of 30.8% within 180 days vs. 3.4% without a stroke (P < 0.001). A meta-analysis of randomized trials (N = 21 173) showed an increase in risk of stroke (odds ratio 1.59; 95% CI 1.11-2.27) but a trend towards reduction in mortality odds ratio (odds ratio 0.87; 95% CI 0.76-1.00).

CONCLUSION

Thrombectomy was associated with a significant increase in stroke. Based on these findings, future trials must carefully collect stroke to determine safety in addition to efficacy.

Clinical efficacy of thrombus aspiration on 5-year clinical outcomes in patients with ST-segment elevation acute myocardial infarction undergoing percutaneous coronary intervention

Background

Adjunctive thrombus aspiration (TA) during primary percutaneous coronary intervention (PCI) was reported to promote better coronary and myocardial reperfusion. However, long-term mortality benefit of TA remains controversial. The objective of this study is to investigate the clinical impact of TA on long-term clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary PCI.

Methods and Results

The CREDO-Kyoto AMI Registry is a large-scale cohort study of acute myocardial infarction patients undergoing coronary revascularization in 2005–2007 at 26 hospitals in Japan. Among 5429 patients enrolled in the registry, the current study population consisted of 3536 patients who arrived at the hospital within 12 hours after the symptom onset and underwent primary PCI. Clinical outcomes were compared between the 2 patient groups with or without TA. During primary PCI procedures, 2239 out of 3536 (63%) patients underwent TA (TA group). The cumulative 5-year incidence of all-cause death was significantly lower in the TA group than in the non-TA group (18.5% versus 23.9%, log-rank P<0.001). After adjusting for confounders, however, the risk for all-cause death in the TA group was not significantly lower than that in the non-TA group (hazard ratio: 0.90, 95% CI: 0.76 to 1.06, P=0.21). The adjusted risks for cardiac death, myocardial infarction, stroke, and target-lesion revascularization were also not significantly different between the 2 groups.

Conclusions

Adjunctive TA during primary PCI was not associated with better 5-year mortality in STEMI patients.

Aspiration Thrombectomy for Treatment of ST-segment Elevation Myocardial Infarction: a Meta-analysis of 26 Randomized Trials in 11,943 Patients

INTRODUCTION AND OBJECTIVES

There is continued debate about the routine use of aspiration thrombectomy in patients with ST-segment elevation myocardial infarction. Our aim was to evaluate clinical and procedural outcomes of aspiration thrombectomy-assisted primary percutaneous coronary intervention compared with conventional primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction.

METHODS

We performed a meta-analysis of 26 randomized controlled trials with a total of 11 943 patients. Clinical outcomes were extracted up to maximum follow-up and random effect models were used to assess differences in outcomes.

RESULTS

We observed no difference in the risk of all-cause death (pooled risk ratio = 0.88; 95% confidence interval, 0.74-1.04; P = .124), reinfarction (pooled risk ratio = 0.85; 95% confidence interval, 0.67-1.08; P = .176), target vessel revascularization (pooled risk ratio = 0.86; 95% confidence interval, 0.73-1.00; P = .052), or definite stent thrombosis (pooled risk ratio = 0.76; 95% confidence interval, 0.49-1.16; P = .202) between the 2 groups at a mean weighted follow-up time of 10.4 months. There were significant reductions in failure to reach Thrombolysis In Myocardial Infarction 3 flow (pooled risk ratio = 0.70; 95% confidence interval, 0.60-0.81; P < .001) or myocardial blush grade 3 (pooled risk ratio = 0.76; 95% confidence interval, 0.65-0.89; P = .001), incomplete ST-segment resolution (pooled risk ratio = 0.72; 95% confidence interval, 0.62-0.84; P < .001), and evidence of distal embolization (pooled risk ratio = 0.61; 95% confidence interval, 0.46-0.81; P = .001) with aspiration thrombectomy but estimates were heterogeneous between trials.

CONCLUSIONS

Among unselected patients with ST-segment elevation myocardial infarction, aspiration thrombectomy-assisted primary percutaneous coronary intervention does not improve clinical outcomes, despite improved epicardial and myocardial parameters of reperfusion.

Randomized trial of primary PCI with or without routine manual thrombectomy

BACKGROUND

During primary percutaneous coronary intervention (PCI), manual thrombectomy may reduce distal embolization and thus improve microvascular perfusion. Small trials have suggested that thrombectomy improves surrogate and clinical outcomes, but a larger trial has reported conflicting results.

METHODS

We randomly assigned 10,732 patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary PCI to a strategy of routine upfront manual thrombectomy versus PCI alone. The primary outcome was a composite of death from cardiovascular causes, recurrent myocardial infarction, cardiogenic shock, or New York Heart Association (NYHA) class IV heart failure within 180 days. The key safety outcome was stroke within 30 days.

RESULTS

The primary outcome occurred in 347 of 5033 patients (6.9%) in the thrombectomy group versus 351 of 5030 patients (7.0%) in the PCI-alone group (hazard ratio in the thrombectomy group, 0.99; 95% confidence interval [CI], 0.85 to 1.15; P=0.86). The rates of cardiovascular death (3.1% with thrombectomy vs. 3.5% with PCI alone; hazard ratio, 0.90; 95% CI, 0.73 to 1.12; P=0.34) and the primary outcome plus stent thrombosis or target-vessel revascularization (9.9% vs. 9.8%; hazard ratio, 1.00; 95% CI, 0.89 to 1.14; P=0.95) were also similar. Stroke within 30 days occurred in 33 patients (0.7%) in the thrombectomy group versus 16 patients (0.3%) in the PCI-alone group (hazard ratio, 2.06; 95% CI, 1.13 to 3.75; P=0.02).

CONCLUSIONS

In patients with STEMI who were undergoing primary PCI, routine manual thrombectomy, as compared with PCI alone, did not reduce the risk of cardiovascular death, recurrent myocardial infarction, cardiogenic shock, or NYHA class IV heart failure within 180 days but was associated with an increased rate of stroke within 30 days. (Funded by Medtronic and the Canadian Institutes of Health Research; TOTAL ClinicalTrials.gov number, NCT01149044.).

Use and impact of thrombectomy in primary percutaneous coronary intervention for acute myocardial infarction with persistent ST-segment elevation: results of the prospective ALKK PCI-registry

BACKGROUND

Data about the impact of thrombectomy in primary percutaneous coronary intervention (PCI) are inconsistent. The aim of our study was an evaluation of both the real-world use of thrombectomy and the impact of thrombectomy on outcome in unselected patients treated with primary PCI for ST-elevation myocardial infarction (STEMI).

METHODS AND RESULTS

We used the data of the prospective ALKK PCI-registry of 35 hospitals from January 2010 to December 2013. A total of 10,755 patients receiving single-vessel primary PCI for acute STEMI were included. In 2176 patients (20.2 %) thrombectomy was performed. There was a wide range of use of thrombectomy in the different ALKK hospitals from 1.1 to 61.7 % (median 18.6 %, quartiles 6.0 and 40.3 %) with a general increase of use over the first years of the study period. In patients with and without thrombectomy there was TIMI 0 flow present before PCI in 6010 patients, TIMI 1 in 1338, TIMI 2 in 2002, and TIMI 3 in 1405. Patients with acute heart failure or cardiogenic shock received significantly more often thrombectomy. Fluoroscopy time (8.1 vs. 7.3 min, p < 0.0001) and dose area product (5373 cGy × cm(2) vs. 4802 cGy × cm(2), p < 0.0001) were significantly higher in patients treated with thrombectomy. The subgroup of patients with TIMI 0 flow before PCI had significantly higher rates of TIMI 3 flow after PCI when treated with thrombectomy (87.1 vs. 84.1 %, p < 0.01), while there was no difference in post-PCI TIMI 3 flow in patients with TIMI 1, 2 or 3 flow before PCI. Rates of major adverse cardiac and cerebrovascular events were similar in both groups in general and in all subgroups of TIMI flow.

CONCLUSIONS

The use of thrombectomy in patients with STEMI is heterogenous between hospitals. Overall, there was no impact of thrombectomy on TIMI 3 patency or mortality after PCI. In the subgroup of STEMI patients with TIMI 0 flow before PCI individualized thrombectomy had a positive impact on restoration of normal blood flow.

Thrombus aspiration in patients with ST elevation myocardial infarction: meta-analysis of 16 randomized trials

OBJECTIVE

The mortality rate is high in some patients undergoing primary percutaneous coronary intervention (PPCI) because of ineffective epicardial and myocardial perfusion. The use of thrombus aspiration (TA) might be beneficial in this group but there is contradictory evidence in current trials. Therefore, using PRISMA statement, we performed a meta-analysis that compares PPCI+TA with PPCI alone.

METHODS

Sixteen studies in which PPCI (n=5262) versus PPCI+TA (n=5256) were performed, were included in this meta-analysis. We calculated the risk ratio (RR) for epicardial and myocardial perfusion, such as the Thrombolysis In myocardial Infarction (TIMI) flow, myocardial blush grade (MBG) and stent thrombosis (ST) resolution (STR), and clinical outcomes, such as all-cause death, recurrent infarction (Re-MI), target vessel revascularization/target lesion revascularization (TVR/TLR), stent thrombosis (ST), and stroke.

RESULTS

Postprocedural TIMI-III flow frequency, postprocedural MBG II-III flow frequency, and postprocedural STR were significantly high in TA+PPCI compared with the PPCI alone group. However, neither all-cause mortality [6.6% vs. 7.4%, RR=0.903, 95% confidence interval (CI): 0.785-1.038, p=0.149] nor Re-MI (2.3% vs. 2.6%, RR=0.884, 95% CI: 0.693-1.127, p=0.319), TVR/TLR (8.2% vs. 8.0%, RR=1.028, 95% CI: 0.900-1.174, p=0.687), ST (0.93% vs. 0.90%, RR=1.029, 95% CI: 0.668-1.583, p=0.898), and stroke (0.5% vs. 0.5%, RR=1.073, 95% CI: 0.588-1.959, p=0.819) rates were comparable between the groups.

CONCLUSION

This meta-analysis is the first updated analysis after publishing the 1-year result of the "Thrombus Aspiration during ST-Segment Elevation Myocardial Infarction" trial, and it showed that TA did not reduce the rate of all-cause mortality, Re-MI, TVR/TLR, ST, and stroke.

Thrombus aspiration for reperfusion in myocardial infarction: Predictors and clinical impact of ineffectiveness

INTRODUCTION AND OBJECTIVES

The benefit of manual thrombus aspiration (TA) in the reperfusion of patients with ST-elevation myocardial infarction (STEMI) has been hotly debated. In most series, failure of TA has been largely unreported. Our objectives were to assess the rate, predictors, and impact on cumulative mortality of failed TA during primary percutaneous coronary intervention (PPCI).

METHODS

This was a single-center, retrospective study of consecutive STEMI patients undergoing PPCI with TA. TA was considered ineffective if, before angioplasty, coronary flow was TIMI <2. Independent predictors of TA failure were assessed by logistic regression, and predictors of cumulative mortality were assessed by Cox regression analysis.

RESULTS

Of 574 patients, TA was used in 417 (72.6%), and was effective in 365 (87.5%) and ineffective in 52 (12.5%). On multivariate analysis, SYNTAX score (OR=1.049, 95% CI: 1.015-1.084, p=0.005) and total ischemic time (OR=1.001, 95% CI: 1.000-1.003, p=0.02) were independent predictors of TA failure. Moderate or severe left ventricular dysfunction (HR=6.256, 95% CI: 1.896-20.644, p=0.003), APPROACH score (HR=1.094, 95% CI: 1.016-1.177, p=0.017), Killip class III/IV (HR=2.953, 95% CI: 1.122-7.770, p=0.028) and creatinine clearance on admission (HR=0.973, 95% CI: 0.953-0.994, p=0.011) were independently related to cumulative mortality at 24 ± 0.82 months.

CONCLUSIONS

Total ischemic time and SYNTAX score were independent predictors of TA failure. However, in medium-term follow-up, ineffective manual TA was not independently related to cumulative mortality.

Effect of coronary thrombus aspiration during primary percutaneous coronary intervention on one-year survival (from the FAST-MI 2010 registry)

Results from randomized trials evaluating thrombus aspiration (TA) in patients with ST-elevation myocardial infarction (STEMI) are conflicting. We assessed 1-year survival in STEMI patients participating in the French Registry of Acute ST-Elevation and non-ST-Elevation Myocardial Infarction (FAST-MI) 2010 according to the use of TA during primary percutaneous coronary intervention (PCI). FAST-MI 2010 is a nationwide French registry that included 4,169 patients with acute myocardial infarction at the end of 2010 in 213 centers. Of those, 2,087 patients had STEMI, of whom 1,538 had primary PCI, with TA used in 671 (44%). Patients with TA were younger (61 ± 13.5 vs 63 ± 14 years), with a similar risk score of the Global Registry of Acute Coronary Events (140 ± 31 vs 143 ± 34) and a shorter median time from symptom onset (245 vs 285 minutes); location of acute myocardial infarction, history of myocardial infarction, PCI, or coronary artery bypass surgery did not differ significantly. Thirty-day mortality was 2.1% versus 2.1% (adjusted p = 0.18), and the rate of 1-year survival was 95.5% versus 94.8%. Using fully adjusted Cox multivariate analysis, hazard ratio for 1-year death was 1.13 (95% confidence interval 0.66 to 1.94). After propensity score matching (480 patients per group), 1-year survival was also similar with both strategies. In a real-world setting of patients admitted with STEMI, the use of TA during primary PCI was not associated with improved 1-year survival.

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.

Aspiration thrombectomy in patients with ST elevation myocardial infarction undergoing primary percutaneous coronary intervention (from the Acute Coronary Syndrome Israeli Survey 2010)

We assessed the impact of aspiration thrombectomy (AT) in patients with ST elevation myocardial infarction undergoing primary percutaneous coronary intervention (PPCI) on major adverse cardiac events at 30 days and 1-year mortality in 517 consecutive patients who were included in the prospective, nationwide, multicenter, observational Acute Coronary Syndrome Israeli Survey in 2010. Two hundred seventeen patients (42%) underwent AT (AT-PPCI) and 300 patients conventional (C) PPCI. Both groups had similar infarct-related artery distribution and ostial or proximal culprit lesion. Patients in AT-PPCI versus C-PPCI had lower systolic blood pressure and worse Killip class on admission, more frequent Thrombolysis In Myocardial Infarction flow 0 or 1 before PPCI (80% vs 56%), less frequent restoration of flow after indwelling a guidewire in the infarct-related artery (32% vs 52%), and more use of IIb/IIIa glycoprotein inhibitors (69% vs 49%), respectively (p ≤0.05 for all comparisons). Thirty-day major adverse cardiac events was similar in the AT-PPCI and C-PPCI groups, 10.6% versus 9.7%, p = 0.73; adjusted odds ratio 0.97, 95% confidence interval 0.45 to 2.10, p = 0.95. One-year mortality was lower in the AT-PPCI versus C-PPCI group, 3.7% versus 6.7%, p = 0.13; adjusted hazard ratio 0.31, 95% confidence interval 0.10 to 0.96, p = 0.042. In conclusion, this study of consecutive patients with ST elevation myocardial infarction undergoing PPCI demonstrates that AT was an independent predictor of reduced 1-year mortality.

Design and rationale of the TOTAL trial: a randomized trial of routine aspiration ThrOmbecTomy with percutaneous coronary intervention (PCI) versus PCI ALone in patients with ST-elevation myocardial infarction undergoing primary PCI

BACKGROUND

A major limitation of primary percutaneous coronary intervention (PPCI) for the treatment of ST-elevation myocardial infarction (STEMI) is impaired microvascular perfusion due to embolization and obstruction of microcirculation with thrombus. Manual thrombectomy has the potential to reduce distal embolization and improve microvascular perfusion. Clinical trials have shown mixed results regarding thrombectomy.

OBJECTIVE

The objective of this study is to evaluate the efficacy of routine upfront manual aspiration thrombectomy during PPCI compared with percutaneous coronary intervention alone in patients with STEMI.

DESIGN

This is a multicenter, prospective, open, international, randomized trial with blinded assessment of outcomes. Patients with STEMI undergoing PPCI are randomized to upfront routine manual aspiration thrombectomy with the Export catheter (Medtronic CardioVascular, Santa Rosa, CA) or to percutaneous coronary intervention alone. The primary outcome is the composite of cardiovascular death, recurrent myocardial infarction, cardiogenic shock, or new or worsening New York Heart Association class IV heart failure up to 180 days. The trial uses an event-driven design and will recruit 10,700 patients.

SUMMARY

The TOTAL trial will determine the effect of routine manual aspiration thrombectomy during PPCI on clinically important outcomes.

Thrombus aspiration during ST-segment elevation myocardial infarction

BACKGROUND

The clinical effect of routine intracoronary thrombus aspiration before primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) is uncertain. We aimed to evaluate whether thrombus aspiration reduces mortality.

METHODS

We conducted a multicenter, prospective, randomized, controlled, open-label clinical trial, with enrollment of patients from the national comprehensive Swedish Coronary Angiography and Angioplasty Registry (SCAAR) and end points evaluated through national registries. A total of 7244 patients with STEMI undergoing PCI were randomly assigned to manual thrombus aspiration followed by PCI or to PCI only. The primary end point was all-cause mortality at 30 days.

RESULTS

No patients were lost to follow-up. Death from any cause occurred in 2.8% of the patients in the thrombus-aspiration group (103 of 3621), as compared with 3.0% in the PCI-only group (110 of 3623) (hazard ratio, 0.94; 95% confidence interval [CI], 0.72 to 1.22; P=0.63). The rates of hospitalization for recurrent myocardial infarction at 30 days were 0.5% and 0.9% in the two groups, respectively (hazard ratio, 0.61; 95% CI, 0.34 to 1.07; P=0.09), and the rates of stent thrombosis were 0.2% and 0.5%, respectively (hazard ratio, 0.47; 95% CI, 0.20 to 1.02; P=0.06). There were no significant differences between the groups with respect to the rate of stroke or neurologic complications at the time of discharge (P=0.87). The results were consistent across all major prespecified subgroups, including subgroups defined according to thrombus burden and coronary flow before PCI.

CONCLUSIONS

Routine thrombus aspiration before PCI as compared with PCI alone did not reduce 30-day mortality among patients with STEMI. (Funded by the Swedish Research Council and others; ClinicalTrials.gov number, NCT01093404.).

What is the optimum adjunctive reperfusion strategy for primary percutaneous coronary intervention?

Acute ST-segment elevation myocardial infarction (STEMI) is a dynamic, thrombus-driven event. As understanding of its pathophysiology has improved, the central role of platelets in initiation and orchestration of this process has become clear. Key components of STEMI include formation of occlusive thrombus, mediation and ultimately amplification of the local vascular inflammatory response resulting in increased vasoreactivity, oedema formation, and microvascular obstruction. Activation, degranulation, and aggregation of platelets are the platforms from which these components develop. Therefore, prompt, potent, and predictable antithrombotic therapy is needed to optimise clinical outcomes after primary percutaneous coronary intervention. We review present pharmacological and mechanical adjunctive therapies for reperfusion and ask what is the optimum combination when primary percutaneous coronary intervention is used as the mode of revascularisation in patients with STEMI.

Stroke after primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction: timing, characteristics, and clinical outcomes

BACKGROUND

Stroke is a rare but potentially devastating complication of acute myocardial infarction. Little is known about stroke timing, characteristics, and clinical outcomes in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention (PCI).

METHODS AND RESULTS

We studied 5372 patients enrolled in the Assessment of Pexelizumab in Acute Myocardial Infarction (APEX-AMI) trial. We analyzed stroke incidence, type, timing, and association with the prespecified 90-day clinical outcomes. Cox proportional hazards modeling was performed to assess the relationship between stroke and outcomes, after adjusting baseline characteristics and analyzing stroke as a time-dependent covariate. Stroke occurred in 69 primary patients with PCI (1.3%). A third of strokes were ischemic (n=23; 33%), 12% (n=8) were hemorrhagic, and the remaining 55% (n=38) were of uncertain type. The median (25th, 75th percentile) time of stroke occurrence was 6 (3, 14) days. Overall, 43% of strokes occurred within 48 hours of PCI, and all hemorrhagic strokes occurred within 48 hours. Stroke was associated with an increased risk of 90-day death (unadjusted hazard ratio [HR], 8.0; 95% confidence interval [CI], 4.8-13.5), congestive heart failure (unadjusted HR, 3.2; 95% CI, 1.3-7.8), and 30-day hospital readmission (unadjusted HR, 3.2; 95% CI, 2.0-5.1). After adjustment, stroke was still strongly associated with 90-day death (adjusted HR, 5.6; 95% CI, 3.2-9.8) and the combination end point of death, congestive heart failure, or cardiogenic shock at 90 days (adjusted HR, 2.4; 95% CI, 1.2-4.7).

CONCLUSIONS

Stroke is an infrequent complication in the setting of ST-segment elevation myocardial infarction treated with primary PCI but is associated with increased morbidity and mortality. Studies to determine mechanisms that may be responsible for strokes that occur >48 hours from primary PCI are warranted.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00091637.

Thrombectomy Devices in Coronary Intervention

Primary percutaneous coronary intervention is the favored mode of reperfusion therapy for ST-elevation myocardial infarction (STEMI) when able to be performed in a timely fashion in appropriately selected patients. However, controversy about the role of coronary thrombectomy in the management of STEMI persists because of a paucity of favorable historical data. After the TAPAS trial thrombectomy has gained favor in recent years. The results of the TOTAL, TASTE, and SMART percutaneous coronary intervention trials will provide further insight into the use of thrombectomy in STEMI. This article examines the relevant trial evidence regarding how to best manage and apply thrombectomy in clinical practice.

Compulsive Thrombus Management in STEMI Interventions

Thrombus is a fundamental concept in the pathophysiology of ST-elevated myocardial infarction (STEMI). Distal embolization and no reflow are associated with less angiographic success, reduced myocardial blush, less ST resolution after primary percutaneous coronary intervention, larger enzymatic infarct size, lower left ventricular ejection fraction at discharge, and higher long-term mortality. We believe that with the use of thrombectomy devices, these shortcomings can be minimized. Based on our experience from the Single Individual Community Experience Registry (SINCERE) database, we formulated a selective thrombus burden management strategy (the Mehta classification) for thrombus management.