The feasibility and safety of routine thrombus aspiration in patients with non-ST-elevation myocardial infarction

Optical coherence tomography analysis of lesion characteristics and thrombus types in non ST-segment elevation myocardial infarction patients

The precise features of lesions in non-ST-segment elevation myocardial infarction (NSTEMI) patients with total occlusion (TO) of the infarct-related artery (IRA) are still unclear. This study employs optical coherence tomography (OCT) to investigate pathological features in NSTEMI patients with or without IRA TO and explores the relationship between thrombus types and IRA occlusive status. This was a single-center retrospective study. A total of 202 patients diagnosed with NSTEMI were divided into two groups: those with Thrombolysis In Myocardial Infarction (TIMI) flow grade 0 before percutaneous coronary intervention (PCI) (referred to as the TO group, n = 100) and those TIMI flow grade 1-3 (referred to as the Non-TO group, n = 102). Baseline characteristics, coronary angiography findings, and OCT results were collected. Multivariate logistic analysis identified factors influencing TO in NSTEMI. The category of NSTEMI was further subdivided based on the type of electrocardiogram (ECG) into two subgroups: ST segment unoffset myocardial infarction (STUMI) and ST segment depression myocardial infarction (STDMI). This division allows for a more specific classification of NSTEMI cases. The TO group had a younger age, higher male representation, more smokers, lower hypertension and cerebrovascular disease incidence, lower left ventricular ejection fraction (LVEF), and higher creatine kinase myocardial band (CKMB) and creatine kinase (CK) peak levels. In the TO group, LCX served as the main IRA (52.0%), whereas in the Non-TO group, LAD was the predominant IRA (45.1%). Compared to the Non-TO group, OCT findings demonstrated that red thrombus/mixed thrombus was more common in the TO group, along with a lower occurrence of white thrombus (p < 0.001). The TO group exhibited a higher prevalence of STUMI (p = 0.001), whereas STDMI was more commonly observed in the Non-TO group (p = 0.001). NSTEMI presents as STUMI and STDMI distinct entities. Red thrombus/mixed thrombus in IRA often indicates occlusive lesions with STUMI on ECG. White thrombus suggests non-occlusive lesions with STDMI on ECG.

Use of Thrombus Aspiration for Patients With Acute Coronary Syndrome: Insights From the Nationwide J-PCI Registry

Background

There is significant regional or institutional variation in the use of thrombus aspiration (TA) in patients undergoing percutaneous coronary intervention (PCI). We investigated the temporal trend in TA use and its association with clinical outcomes in acute coronary syndrome using the nationwide J‐PCI (Japanese PCI) registry.

Methods and Results

Between 2016 and 2018, patients with acute coronary syndrome undergoing PCI (n=282 606; median age, 71.0 years; interquartile range, 62.0–79.0 years; women, 24.7%) at 1124 hospitals were stratified on the basis of whether TA was performed (TA and non‐TA). The patients were subdivided according to clinical presentation (ST‐segment–elevation myocardial infarction, non–ST‐segment–elevation myocardial infarction, and unstable angina). Successful PCI, defined as the achievement of TIMI (Thrombolysis in Myocardial Infarction) 3 flow, and in‐hospital mortality were assessed. During the study period, 83 422 patients (29.5%) underwent TA (52.9%, 23.5%, and 5.2% for ST‐segment–elevation myocardial infarction, non–ST‐segment–elevation myocardial infarction, and unstable angina, respectively), and the TA implementation rate remained relatively stable throughout. Patients treated with TA had higher rate of successful PCI than non‐TA (98.7% versus 97.8%; P<0.001). TA was not associated with in‐hospital death among patients with ST‐segment–elevation myocardial infarction (adjusted odds ratio [aOR], 1.02 [95% CI, 0.94–1.12]). However, TA use was associated with higher rates of in‐hospital death in patients with non–ST‐segment–elevation myocardial infarction ( aOR, 1.51 [95% CI, 1.23–1.86]) or unstable angina ( aOR, 1.95 [95% CI, 1.37–2.79]).

Conclusions

In our retrospective analysis of the nationwide PCI registry, TA use was associated with a higher achievement of successful PCI without impairing in‐hospital mortality among patients with ST‐segment–elevation myocardial infarction. Nevertheless, its use should be cautioned in less‐established indications (eg, non–ST‐segment–elevation myocardial infarction and unstable angina).

Effect of Coronary Thrombus Aspiration in Non ST Elevation Acute Coronary Syndrome Patients on Three-Year Survival- Does it add any Benefit?

We assessed the effect of thrombus aspiration (TA) during percutaneous coronary intervention (PCI) on in-hospital and 3-year mortality in consecutive non-ST segment elevation myocardial infarction (n = 189) and unstable angina pectoris (n = 148) patients (n = 337) between 2011 and 2016. In total, 153 patients (45.4%) underwent TA. The number of patients with postoperative thrombolysis in terms of myocardial infarction grade 3 blood flow (P < .001) and myocardial blush grade 3 (P < .001) were significantly higher in all TA groups. At 6-, 12- and 24-month post-PCI, the mean left ventricular ejection fraction was significantly higher in the all TA groups versus the stand alone PCI group (P < .001). Thrombus aspiration was associated with a significant improvement both in epicardial flow, myocardial perfusion and left ventricular ejection fraction. Thrombus aspiration during PCI in all acute coronary syndrome (except ST segment elevation) patients was associated with better survival compared with stand alone PCI group at 3-year follow-up (P = .019).

Myocardial Infarction with and without ST-segment Elevation: a Contemporary Reappraisal of Similarities and Differences

Understanding the similarities and differences between myocardial infarction with or without ST-segment elevation is an essential step for proper patients' management in current practice. Both syndromes are caused by critical stenosis or total occlusion of coronary arteries (mostly due to thrombosis on atherosclerotic plaque), and manifest with a similar clinical presentation. Recent epidemiologic studies show that the relative incidence of ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) moves in an opposite fashion (decreasing and increasing respectively), with a prognosis that is worse at short-term follow-up for STEMI but comparable at long-term. Current management differs, as for STEMIs, immediate reperfusion is recommended, while for NSTEMIs, risk stratification is mandatory in order to stratify patients' risk, and then decide the timing for coronary angiography. Periprocedural and technical aspects of the interventional management, as well as antithrombotic medications, are for the most similarly implemented in the two types of MI, with routine radial access, DES implant, and novel P2Y12 inhibitors representing the standard of care in both cases. The following review article aims to compare the two types of MI, with and without persistent STsegment elevation. The main purpose is to explore their similarities and differences and address areas of uncertainty with regards to clinical presentation, therapeutic management, and prognosis. The identification of high-risk NSTEMI patients is important as they may require an individualised approach that can substantially overlap with current STEMI recommendations, and their mortality remains high if their management is delayed.

Long-term outcome after thrombus aspiration in non-ST-elevation myocardial infarction: results from the TATORT-NSTEMI trial : Thrombus aspiration in acute myocardial infarction

AIMS

To investigate the long-term prognostic value of aspiration thrombectomy in conjunction with primary percutaneous coronary intervention (PCI) compared to conventional PCI in patients with non-ST-elevation myocardial infarction (NSTEMI).

METHODS

In the randomized TATORT-NSTEMI (Thrombus aspiration in thrombus containing culprit lesions in non-ST-elevation myocardial infarction) trial, NSTEMI patients with thrombus containing culprit lesions were randomized to either PCI with aspiration thrombectomy or conventional PCI. The endpoint was a combination of all-cause death, reinfarction and new congestive heart failure.

RESULTS

From 440 patients initially randomized, outcome data were available in 432 (98.2%) patients at a median follow-up of 4.9 (interquartile range [IQR] 4.4-5.0) years. Thrombectomy was associated with a significant reduction of the combined endpoint compared to conventional PCI (19.9% vs. 30.7%, p = 0.01). This finding was primarily driven by a reduced rate of reinfarction with thrombectomy (3.4% vs. 10.3%, p = 0.01). Thrombectomy was still independently associated with the combined endpoint after multivariable adjustment (hazard ratio [HR] 0.47, 95% confidence interval [CI] 0.30-0.76, p = 0.002). Findings were consistent across all analyzed subgroups (p values for interaction all > 0.05).

CONCLUSIONS

In NSTEMI, thrombus aspiration is associated with favorable clinical outcome during long-term follow-up.

CLINICAL TRIAL REGISTRATION

NCT01612312.

Thrombus aspiration catheter is a Dottering balloon

Coronary angiogram in a young man with history of STEMI with delayed presentation revealed subtotal occlusion of left anterior descending artery (LAD) with large thrombotic filling defect distal to the critical lesion. PCI was preferred without delay because of ongoing chest pain. Several runs of thrombus aspiration failed to detect any visible thrombus. However, the immediate angiogram after thrombus aspiration showed complete distal embolization of the thrombus which could have been achieved by Dottering or balloon dilatation. In contrary to the general perception, does thrombus aspiration push more thrombus than it can aspirate?

No clinical benefit from manual thrombus aspiration in patients with non-ST-elevation myocardial infarction

INTRODUCTION

There are scarce data on the usefulness of manual thrombectomy among patients with non-ST-elevation myocardial infarction (NSTEMI). Early positive reports were not supported by the clinical outcome in the recent TATORT-NSTEMI (Thrombus Aspiration in Thrombus Containing Culprit Lesions in Non-ST-Elevation Myocardial Infarction) study.

AIM

To analyze the long-term outcome of NSTEMI patients treated with manual thrombectomy during percutaneous coronary intervention (PCI) in the Polish multicenter National Registry of Drug Eluting Stents (NRDES) study.

MATERIAL AND METHODS

There were 13 catheterization laboratories in Poland that enrolled patients in NRDES Registry in 2010-2011. Patients with a diagnosis of NSTEMI were divided into two groups: those that were treated with manual thrombectomy for their primary PCI (T) and those who were not (NT).

RESULTS

There were 923 patients diagnosed with NSTEMI in NRDES. Aspiration thrombectomy was used in 71 (7.7%) patients and the remaining 852 (92.3%) NSTEMI cases were treated without thrombectomy during the index PCI. Thrombectomy was more often used in patients with TIMI less than 1, thrombus grades 4 and 5 and older male patients. Percutaneous coronary interventions complications such as distal embolization and slow flow were more often observed in the thrombectomy subgroup. Overall mortality at 1 year was 1.69% in the T and 5.92% in the NT group (p = 0.24 and p = 0.32 after propensity score matching adjustment with p = 0.11 in the multivariate logistic regression model).

CONCLUSIONS

There was no mortality benefit from thrombus aspiration in NSTEMI patients at 1-year follow-up.

Manual Thrombus Aspiration and the Improved Survival of Patients With Unstable Angina Pectoris Treated With Percutaneous Coronary Intervention (30 Months Follow-Up)

The clinical effect of intracoronary thrombus aspiration during percutaneous coronary intervention in patients with unstable angina pectoris is unknown. In this study, we aimed to assess how thrombus aspiration during percutaneous coronary intervention affects in-hospital and 30-month mortality and complications in patients with unstable angina pectoris.We undertook an observational cohort study of 645 consecutive unstable angina pectoris patients who had performed percutaneous coronary intervention from February 2011 to March 2013. Before intervention, 159 patients who had culprit lesion with thrombus were randomly assigned to group 1 (thrombus aspiration group) and group 2 (stand-alone percutaneous coronary intervention group). All patients were followed-up 30 months until August 2015.Thrombus aspiration was performed in 64 patients (46%) whose cardiac markers (ie, creatinine kinase [CK-MB] mass and troponin T) were significantly lower after percutaneous coronary intervention than in those of group 2 (CK-MB mass: 3.80 ± 1.11 vs 4.23 ± 0.89, P = 0.012; troponin T: 0.012 ± 0.014 vs 0.018 ± 0.008, P = 0.002). Left ventricular ejection fraction at 6, 12, and 24 months postintervention was significantly higher in the group 1. During a mean follow-up period of 28.87 ± 6.28 months, mortality rates were 6.3% in the group 1 versus 12.9% in the group 2. Thrombus aspiration was also associated with significantly less long-term mortality in unstable angina pectoris patients (adjusted HR: 4.61, 95% CI: 1.16-18.21, P = 0.029).Thrombus aspiration in the context of unstable angina pectoris is associated with a limited elevation in cardiac enzymes during intervention that minimises microembolization and significantly improves both of epicardial flow and myocardial perfusion, as shown by angiographic TIMI flow grade and frame count. Thrombus aspiration during percutaneous coronary intervention in unstable angina pectoris patients has better survival over a 30-month follow-up period.

Clonal restriction and predominance of regulatory T cells in coronary thrombi of patients with acute coronary syndromes

AIMS

Regulatory T cells (Treg) exert anti-inflammatory and atheroprotective effects in experimental atherosclerosis. Treg can be induced against specific antigens using immunization strategies associated with clonal restriction. No data exist on Treg in combination with clonal restriction of T cells in patients with acute coronary syndromes (ACS).

METHODS AND RESULTS

Among T cell subsets characterized by flow cytometry, Treg (CD4(+) CD25(+) CD127(low)) were twice as frequent in coronary thrombi compared with peripheral blood. Treg prevailed among T cell subsets identified in coronary thrombi. To evaluate clonal restriction, genomic DNA was extracted from coronary thrombi and peripheral blood in order to evaluate T cell receptor (TCR) β chain diversity by means of Multi-N-plex PCR using a primer specific for all TCR β V gene segments and another primer specific for TCR β J gene segments. T cell receptor diversity was reduced in thrombi compared with peripheral blood (intra-individual comparisons in 16 patients) with 8 gene rearrangements in the TCR common in at least 6 out of 16 analysed coronary thrombi. Compared with age-matched healthy controls (n = 16), TCR diversity was also reduced in peripheral blood of patients with ACS; these findings were independent of peripheral T cell numbers.

CONCLUSION

We provide novel evidence for a perturbed T cell compartment characterized by clonal restriction in peripheral blood and coronary thrombi from patients with ACS. Our findings warrant further studies on Treg as novel therapeutic targets aimed at enhancing this anti-inflammatory component of adaptive immunity in human atherothrombosis.

Safety of lone thrombus aspiration without concomitant coronary stenting in selected patients with acute myocardial infarction

AIMS

Although the benefit of concomitant thrombus aspiration (TA) in primary percutaneous coronary intervention (PPCI) treatment of acute ST-segment elevation myocardial infarction (STEMI) has been demonstrated, very little information is available on its safety as a lone revascularisation technique in this setting. We present our experience in a cohort of patients with STEMI treated only with TA, without concomitant interventional devices.

METHODS AND RESULTS

In 28 patients with STEMI, PPCI was performed using only TA on the grounds of an excellent angiographic result and in order to avoid the potential risks associated with balloon dilatation or stenting. The patients were younger than in the overall PPCI population (n=1,737) at our institution (52±18 vs. 63±14 years, p<0.001), with a history of atrial fibrillation in six (21%), cocaine abuse in three (11%) and mechanical cardiac valves in two (7%). Twenty-eight patients (89%) presented STEMI with Killip class I, two (7%) with cardiogenic shock, and two (7%) with sudden cardiac death. A significant reduction in TIMI thrombus grade (5 [4-5] to 1 [0-1.75], p<0.001) and coronary stenosis percentage (%) (87.2±21.3 to 11.3±0.9, p<0.001) as well as an increase in final TIMI flow (0 [0-2] to 3 [3-3], p<0.001) and minimum luminal diameter (mm) (0.89±1.01 to 2.42±0.70, p<0.001) were noted after TA. Transient no-reflow phenomenon, residual intracoronary thrombus and minor distal thrombus embolisation were observed in two (7.1%), 11 (39.3%) and 10 (25.7%) patients, respectively. All but one patient remained asymptomatic during hospital admission. Scheduled control angiography was performed 6±2 days (min-max, 3-10 days) after PPCI in 11 (39%) patients, demonstrating coronary artery patency and TIMI flow grade 3 in all patients. During clinical follow-up, successfully performed in all patients at 40±23 months (min-max, six to 95 months), there was one sudden cardiac death (4%) and three (11%) non-cardiac deaths. One patient (4%) was admitted with non-STEMI (new coronary angiogram without stenosis) and the remaining 22 (78.5%) remained asymptomatic and free of cardiac events.

CONCLUSIONS

Our series suggests that lone TA might be safely performed as a primary revascularisation procedure in STEMI in selected cases. Further information based on additional and larger studies is recommended to confirm our findings.

Thrombus Aspiration in ThrOmbus containing culpRiT lesions in Non-ST-Elevation Myocardial Infarction (TATORT-NSTEMI): study protocol for a randomized controlled trial

Background

Current guidelines recommend thrombus aspiration in patients with ST-elevation myocardial infarction (STEMI); however, there are insufficient data to unequivocally support thrombectomy in patients with non-STEMI (NSTEMI).

Methods/Design

The TATORT-NSTEMI (Thrombus Aspiration in ThrOmbus containing culpRiT lesions in Non-ST-Elevation Myocardial Infarction) trial is a prospective, controlled, multicenter, randomized, open-label trial enrolling 460 patients. The hypothesis is that, against a background of early revascularization, adjunctive thrombectomy leads to less microvascular obstruction (MO) compared with conventional percutaneous coronary intervention (PCI) alone, as assessed by cardiac magnetic resonance imaging (CMR) in patients with NSTEMI. Patients will be randomized in a 1:1 fashion to one of the two treatment arms. The primary endpoint is the extent of late MO assessed by CMR. Secondary endpoints include early MO, infarct size, and myocardial salvage assessed by CMR as well as enzymatic infarct size and angiographic parameters, such as thrombolysis in myocardial infarction flow post-PCI and myocardial blush grade. Furthermore, clinical endpoints including death, myocardial re-infarction, target vessel revascularization, and new congestive heart failure will be recorded at 6 and 12 months. Safety will be assessed by the incidence of bleeding and stroke.

Summary

The TATORT-NSTEMI trial has been designed to test the hypothesis that thrombectomy will improve myocardial perfusion in patients with NSTEMI and relevant thrombus burden in the culprit vessel reperfused by early PCI.

Trial registration

The trial is registered under http://www.clinicaltrials.gov: NCT01612312.

Thrombus Aspiration during Percutaneous coronary intervention in Acute non-ST-elevation myocardial infarction Study (TAPAS II)-Study design

Background and Objective. The Thrombus Aspiration during Percutaneous coronary intervention in Acute myocardial infarction Study (TAPAS) has shown that thrombus aspiration improves myocardial perfusion and clinical outcome compared with conventional primary percutaneous coronary intervention (PCI) in patients with ST-segment-elevation myocardial infarction. Impaired myocardial perfusion due to spontaneous or angioplasty-induced embolisation of atherothrombotic material also occurs in patients with non-ST-elevation myocardial infarction (NSTEMI). The aim of this study is to determine whether thrombus aspiration before stent implantation will result in improved myocardial perfusion in patients with NSTEMI compared with conventional PCI.Study design. The study is a single-centre, prospective, randomised trial with blinded evaluation of endpoints. The planned inclusion is 540 patients with acute NSTEMI who are candidates for urgent PCI. Patients are randomised to treatment with manual thrombus aspiration or to conventional PCI. The primary endpoint is the incidence of myocardial blush grade 3 after PCI. Secondary endpoints are coronary angiographic, histopathological, enzymatic, electrocardiographic and clinical outcomes including major adverse events at 30 days and one year.Implications. If thrombus aspiration leads to significant improvement of myocardial perfusion in patients with acute NSTEMI it may become part of the standard interventional approach. (Neth Heart J 2009;17:409-13.).

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.).

[Impact of the angles and the age of the thrombus on efficacity of thromboaspiration device. A bench study]

INTRODUCTION

Coronary thrombectomy is usually used to treat acute coronary syndrome. Many studies evaluated its benefit in this context however, it is still unknown if coronary characteristics are predictive of success or failure. The aim of our laboratory bench study was to evaluate the impact of angiographic characteristics on the thromboaspiration efficiency.

METHODS

Glass tubes of 150 mm in the length were used, with five diameters: 2; 2.6; 3; 3.6 and 4 mm; and for each diameter, three angulations: no angulation; 90° and 120°. Blood sample were taken from healthy subject and thrombi of 3 and 6 hours old were performed, with a constant volume for each test. Thromboaspirations were performed with an Export(®) catheter (Medtronic). The primary endpoint was total thrombectomy. A total of 240 thromboaspirations were performed.

RESULTS

A total thrombectomy was obtained for 71.2% of the tests. It was achieved more frequently with the smaller diameter, respectively: 100% for 2 mm, 81.3% for 2.6 mm, 89.6% for 3 mm vs 54.2% for 3.6 mm and 31.3% for 4 mm (P<0.001). No differences were observed between the 2 thrombi ages (73.3% for the 3 hours old thrombi and 69.2% for the 6 hours old thrombi, P = 0.476), nor between the three tube's angulations (77.5% for no angle, 66.3% for 90° and 70.0% for 120°, P = 0.278).

RESULTS AND CONCLUSION

This study shows an impact of the coronary diameters on the rate of thromboaspiration success with an Export(®) catheter. Beyond 3 mm of diameter, the rate of success is divided by 2: for diameters less or equal to 3 mm, 90.3% of success vs 42.7% for diameters greater than 3 mm (P<0.001). There is no difference of efficiency between the 3 and 6 hours old thrombi, neither between the tube's angulations. However, this is a preliminary and further works are needed to clarify how to optimize the aspiration and the impact of other catheters.

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.