Randomized trial of primary PCI with or without routine manual thrombectomy

Safety and efficacy of low-dose intracoronary thrombolysis during primary percutaneous coronary intervention in patients with ST elevation myocardial infarction: A meta-analysis of randomized trials

BACKGROUND

In patients with ST elevation myocardial infarction (STEMI), intracoronary thrombolysis (ICT) may reduce thrombotic burden and microvascular obstruction in the infarct-related artery. We performed a meta-analysis to evaluate the role of adjunctive low-dose ICT during primary percutaneous coronary intervention (PPCI) in improving clinical outcomes and indices of microvascular function.

METHODS

We searched electronic databases (Cochrane, EMBASE, Medline; inception to October 2023) for randomized controlled trials (RCTs) evaluating the effects of adjunctive ICT in STEMI patients undergoing PPCI, compared with placebo or usual care. Study-level data on efficacy and safety outcomes were pooled using a fixed-effect model. The primary outcome was major adverse cardiovascular events (MACE).

RESULTS

A total of 8 RCTs were included, comprising a total of 1,208 patients. Compared with placebo or usual care, ICT was associated with a trend towards lower MACE (11.3% vs. 15.1%; odds ratio [OR] 0.73, 95% confidence interval [CI] 0.51 to 1.04). Infarct size (mean difference [MD] -1.98, 95% CI -3.68 to -0.27; p=0.02), ST-segment resolution (MD: 6.06, 95% CI: 0.69 to 11.43; p=0.03) and corrected TIMI frame count (MD: -2.26, 95% CI: -4.03 to -0.48; p=0.01; I2=78%). The odds for major (0.7% vs. 0.7%; OR 0.94, 95% CI 0.24 to 3.7; p=0.93) and minor bleeding (7.7% vs. 4.3%; OR 1.81, 95% CI 0.87 to 3.76; p=0.11) were similar between the two groups.

CONCLUSION

Adjunctive low-dose ICT during PPCI is safe, associated with a trend towards lower MACE, and may improve surrogate markers of microvascular function. These hypothesis-generating findings warrant validation in larger, adequately powered randomized trials.

Initial experience with a novel stent-based mechanical thrombectomy device for management of acute myocardial infarction cases with large thrombus burden

BACKGROUND

Patients with acute myocardial infarction (AMI) and large thrombus burden (LTB) still represent a challenge. Afflicted patients have a high morbidity and mortality. Aspiration thrombectomy is often ineffective in those cases. Mechanical thrombectomy devices (MTDs), which are effective for management of ischemic strokes, were recently CE-approved for treatment of thrombotic coronary lesions. Real-world data about their performance in AMI cases with LTB are scarce. This study sought to summarize our early experience with a novel MTD device in this context.

METHODS

We analyzed consecutive patients from the prospective OPTIMISER registry (NCT04988672), who have been managed with the NeVa™ MTD (Vesalio, USA) for AMI with LTB at a tertiary cardiology facility. Outcomes of interest included, among others, periprocedural complications, target lesion failure (TLF), target lesion revascularization (TLR) and target vessel myocardial infarction (TV-MI).

RESULTS

Overall, 15 patients underwent thrombectomy with the NeVa™ device. Thrombectomy was successfully performed in 14 (93%) patients. Final TIMI 3 flow was achieved in 13 (87%) patients, while 2 (13%) patients had TIMI 2 flow. We encountered no relevant periprocedural complications, especially no stroke, stent thrombosis or vessel closure. After a mean follow-up time of 26 ± 2.9 months, 1 (7%) patient presented with TLR due to stent thrombosis (10 months after treatment with the MTD and stenting).

CONCLUSIONS

In AMI patients with LTB, the deployment of the novel NeVa™ MTD seems efficient and safe. Further randomized trials are warranted to assess whether the use of the NeVa™ device in cases with LTB improves procedural and clinical outcomes.

Acute myocardial infarction and ischaemic stroke: differences and similarities in reperfusion therapies-a review

Acute ST-elevation myocardial infarction (STEMI) and acute ischaemic stroke (AIS) share a number of similarities. However, important differences in pathophysiology demand a disease-tailored approach. In both conditions, fast treatment plays a crucial role as ischaemia and eventually infarction develop rapidly. Furthermore, in both fields, the introduction of fibrinolytic treatments historically preceded the implementation of endovascular techniques. However, in contrast to STEMI, only a minority of AIS patients will eventually be considered eligible for reperfusion treatment. Non-invasive cerebral imaging always precedes cerebral angiography and thrombectomy, whereas coronary angiography is not routinely preceded by non-invasive cardiac imaging in patients with STEMI. In the late or unknown time window, the presence of specific patterns on brain imaging may help identify AIS patients who benefit most from reperfusion treatment. For STEMI, a uniform time window for reperfusion up to 12 h after symptom onset, based on old placebo-controlled trials, is still recommended in guidelines and generally applied. Bridging fibrinolysis preceding endovascular treatment still remains the mainstay of reperfusion treatment in AIS, while primary percutaneous coronary intervention is the strategy of choice in STEMI. Shortening ischaemic times by fine-tuning collaboration networks between ambulances, community hospitals, and tertiary care hospitals, optimizing bridging fibrinolysis, and reducing ischaemia-reperfusion injury are important topics for further research. The aim of this review is to provide insights into the common as well as diverging pathophysiology behind current reperfusion strategies and to explore new ways to enhance their clinical benefit.

Restoring microvascular circulation with diagnostic ultrasound and contrast agent: Rationale and Design of the REDUCE trial

OBJECTIVES

This study aims to evaluate the efficacy and cost-effectiveness of sonothrombolysis delivered pre and post primary percutaneous coronary intervention (pPCI) on infarct size assessed by cardiac MRI, in patients presenting with STEMI, when compared against sham procedure.

BACKGROUND

More than a half of patients with successful pPCI have significant microvascular obstruction and residual infarction. Sonothrombolysis is a therapeutic use of ultrasound with contrast enhancement that may improve microcirculation and infarct size. The benefits and real time physiological effects of sonothrombolysis in a multicentre setting are unclear.

METHODS

The REDUCE (Restoring microvascular circulation with diagnostic ultrasound and contrast agent) trial is a prospective, multicentre, patient and outcome blinded, sham-controlled trial. Patients presenting with STEMI will be randomized to one of two treatment arms, to receive either sonothrombolysis treatment or sham echocardiography before and after pPCI. This tailored design is based on preliminary pilot data from our centre, showing that sonothrombolysis can be safely delivered, without prolonging door to balloon time. Our primary endpoint will be infarct size assessed on day 4±2 on Cardiac Magnetic Resonance (CMR). Patients will be followed up for six months post pPCI to assess secondary endpoints. Sample size calculations indicate we will need 150 patients recruited in total.

CONCLUSIONS

This multicentre trial will test whether sonothrombolysis delivered pre and post primary PCI can improve patient outcomes and is cost-effective, when compared with sham ultrasound delivered with primary PCI. The results from this trial may provide evidence for the utilization of sonothrombolysis as an adjunct therapy to pPCI to improve cardiovascular outcomes in STEMI. ANZ Clinical Trial Registration number: ACTRN 12620000807954.

Design and Rationale of the CLEAR SYNERGY (OASIS 9) Trial: A 2x2 Factorial Randomized Controlled Trial of Colchicine versus placebo and Spironolactone versus placebo in Patients with Myocardial Infarction

BACKGROUND

Patients experiencing myocardial infarction (MI) remain at high risk of future major adverse cardiovascular events (MACE). While low-dose colchicine and spironolactone have been shown to decrease post-MI MACE, more data are required to confirm their safety and efficacy in an unselected post-MI population. Therefore, we initiated the CLEAR SYNERGY (OASIS 9) trial to address these uncertainties.

METHODS

The CLEAR SYNERGY trial is a 2 × 2 factorial randomized controlled trial of low-dose colchicine 0.5 mg daily versus placebo and spironolactone 25 mg daily versus placebo in 7,062 post-MI participants who were within 72 hours of the index percutaneous coronary intervention (PCI). We blinded participants, healthcare providers, research personnel, and outcome adjudicators to treatment allocation. The primary outcome for colchicine is the first occurrence of the composite of cardiovascular death, recurrent MI, stroke, or unplanned ischemia-driven revascularization. The co-primary outcomes for spironolactone are (1) the composite of the total numbers of cardiovascular death or new or worsening heart failure and (2) the first occurrence of the composite of cardiovascular death, new or worsening heart failure, recurrent MI or stroke. We finished recruitment with 7,062 participants from 104 centers in 14 countries on November 8, 2022, and plan to present the results in the fall of 2024.

CONCLUSIONS

CLEAR SYNERGY is a large international randomized controlled trial that will inform the effects of low-dose colchicine and spironolactone in largely unselected post-MI patients who undergo PCI. (ClinicalTrials.gov Identifier: NCT03048825).

SYNERGY-Everolimus-Eluting Stent With a Bioabsorbable Polymer in ST-Elevation Myocardial Infarction: CLEAR SYNERGY OASIS-9 Registry

Our objective was to evaluate the clinical effectiveness of the SYNERGY stent (Boston Scientific Corporation, Marlborough, Massachusetts) in patients with ST-elevation myocardial infarction (STEMI). The only drug-eluting stent approved for treatment of STEMI by the Food and Drug Administration is the Taxus stent (Boston Scientific) which is no longer commercially available, so further data are needed. The CLEAR (Colchicine and spironolactone in patients with myocardial infarction) SYNERGY stent registry was embedded into a larger randomized trial of patients with STEMI (n = 7,000), comparing colchicine versus placebo and spironolactone versus placebo. The primary outcome for the SYNERGY stent registry is major adverse cardiac events (MACE) as defined by cardiovascular death, recurrent MI, or unplanned ischemia-driven target vessel revascularization within 12 months. We estimated a MACE rate of 6.3% at 12 months after primary percutaneous coronary intervention for STEMI based on the Thrombectomy vs percutaneous coronary intervention alone in STEMI (TOTAL) trial. Success was defined as upper bound of confidence interval (CI) to be less than the performance goal of 9.45%. Overall, 733 patients were enrolled from 8 countries with a mean age 60 years, 19.4% diabetes mellitus, 41.3% anterior MI, and median door-to-balloon time of 72 minutes. The MACE rate was 4.8% (95% CI 3.2 to 6.3%) at 12 months which met the success criteria against performance goal of 9.45%. The rates of cardiovascular death, recurrent MI, or target vessel revascularization were 2.7%, 1.9%, 1.0%, respectively. The rates of acute definite stent thrombosis were 0.3%, subacute 0.4%, late 0.4%, and cumulative stent thrombosis of 1.1% at 12 months. In conclusion, the SYNERGY stent in STEMI performed well and was successful compared with the performance goal based on previous trials.

Coronary microvascular obstruction and dysfunction in patients with acute myocardial infarction

Despite prompt epicardial recanalization in patients presenting with ST-segment elevation myocardial infarction (STEMI), coronary microvascular obstruction and dysfunction (CMVO) is still fairly common and is associated with poor prognosis. Various pharmacological and mechanical strategies to treat CMVO have been proposed, but the positive results reported in preclinical and small proof-of-concept studies have not translated into benefits in large clinical trials conducted in the modern treatment setting of patients with STEMI. Therefore, the optimal management of these patients remains a topic of debate. In this Review, we appraise the pathophysiological mechanisms of CMVO, explore the evidence and provide future perspectives on strategies to be implemented to reduce the incidence of CMVO and improve prognosis in patients with STEMI.

Angiographic characteristics of patients with STEMI and COVID-19: Insights from NACMI registry

BACKGROUND

To date, there has been no independent core lab angiographic analysis of patients with COVID-19 and STEMI. The study characterized the angiographic parameters of patients with COVID-19 and STEMI.

METHODS

Angiograms of patients with COVID-19 and STEMI from the North American COVID-19 Myocardial Infarction (NACMI) Registry were sent to a Core Laboratory in Vancouver, Canada. Culprit lesion(s), Thrombolysis In Myocardial Infarction (TIMI) flow, Thrombus Grade Burden (TGB), and percutaneous coronary intervention (PCI) outcome were assessed.

RESULTS

From 234 patients, 74% had one culprit lesion, 14% had multiple culprits and 12% had no culprit identified. Multivessel thrombotic disease and multivessel CAD were found in 27% and 53% of patients, respectively. Stent thrombosis accounted for 12% of the presentations and occurred in 55% of patients with previous coronary stents. Of the 182 who underwent PCI, 60 (33%) had unsuccessful PCI due to post-PCI TIMI flow <3 (43/60), residual high thrombus burden (41/60) and/or thrombus related complications (27/60). In-hospital mortality for successful, partially successful, and unsuccessful PCI was 14%, 13%, and 27%, respectively. Unsuccessful PCI was associated with increased risk of in-hospital mortality (risk ratio [RR] 1.96; 95% CI: 1.05-3.66, P = .03); in the adjusted model this estimate was attenuated (RR: 1.24; 95% CI: 0.65-2.34, P = .51).

CONCLUSION

In patients with COVID-19 and STEMI, thrombus burden was pervasive with notable rates of multivessel thrombotic disease and stent thrombosis. Post-PCI, persistent thrombus and sub-optimal TIMI 3 flow rates led to one-third of the PCI's being unsuccessful, which decreased over time but remained an important predictor of in-hospital mortality.

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.

Use of the Indigo CAT RX aspiration system during percutaneous coronary intervention

BACKGROUND

The use of the Indigo CAT RX Aspiration System (Penumbra Inc.) during percutaneous coronary intervention has received limited study.

METHODS

We retrospectively examined the clinical, angiographic, and procedural characteristics, outcomes, and follow-up of patients who underwent mechanical aspiration thrombectomy with the Indigo CAT RX system (Penumbra Inc.) at a large tertiary care hospital between January 2019 and April 2023.

RESULTS

During the study period, 83 patients (85 lesions) underwent thrombectomy with the Indigo CAT RX. Mean patient age was 64.9 ± 14.48 years and 31.2% were women. The most common presentations were ST-segment elevation myocardial infarction (MI) (66.2%) and non-ST-segment elevation MI (26.5%). A final thrombolysis in MI flow grade of 3 and final myocardial blush grade of 3 were achieved in 76% and 46% of the cases, respectively. Technical success was achieved in 88.9% of the cases that included Indigo CAT RX treatment only, compared with 57.1% of the cases that also included manual aspiration. There were no device-related serious adverse events. At 30-day postprocedure, the incidence of major adverse cardiac events (composite of cardiovascular death, recurrent MI, cardiogenic shock, new or worsening New York Heart Association Class IV heart failure, stroke) was 8.5%: 1.3% stroke (postprocedure, in-hospital), 1.3% MI, 6.1% cardiac death, and 7.5% developed cardiogenic shock.

CONCLUSIONS

Use of the Indigo CAT RX system is associated with high technical success and acceptable risk of complications, including stroke.

No-Reflow Prediction in Acute Coronary Syndrome During Percutaneous Coronary Intervention: The NORPACS Risk Score

BACKGROUND

Suboptimal coronary reperfusion (no reflow) is common in acute coronary syndrome percutaneous coronary intervention (PCI) and is associated with poor outcomes. We aimed to develop and externally validate a clinical risk score for angiographic no reflow for use following angiography and before PCI.

METHODS

We developed and externally validated a logistic regression model for prediction of no reflow among adult patients undergoing PCI for acute coronary syndrome using data from the Melbourne Interventional Group PCI registry (2005-2020; development cohort) and the British Cardiovascular Interventional Society PCI registry (2006-2020; external validation cohort).

RESULTS

A total of 30 561 patients (mean age, 64.1 years; 24% women) were included in the Melbourne Interventional Group development cohort and 440 256 patients (mean age, 64.9 years; 27% women) in the British Cardiovascular Interventional Society external validation cohort. The primary outcome (no reflow) occurred in 4.1% (1249 patients) and 9.4% (41 222 patients) of the development and validation cohorts, respectively. From 33 candidate predictor variables, 6 final variables were selected by an adaptive least absolute shrinkage and selection operator regression model for inclusion (cardiogenic shock, ST-segment-elevation myocardial infarction with symptom onset >195 minutes pre-PCI, estimated stent length ≥20 mm, vessel diameter <2.5 mm, pre-PCI Thrombolysis in Myocardial Infarction flow <3, and lesion location). Model discrimination was very good (development C statistic, 0.808; validation C statistic, 0.741) with excellent calibration. Patients with a score of ≥8 points had a 22% and 27% risk of no reflow in the development and validation cohorts, respectively.

CONCLUSIONS

The no-reflow prediction in acute coronary syndrome risk score is a simple count-based scoring system based on 6 parameters available before PCI to predict the risk of no reflow. This score could be useful in guiding preventative treatment and future trials.

Primary percutaneous intervention in an unusual vessel using an unusual technique: a case report

Background

Primary percutaneous intervention (PPCI) of the saphenous vein graft (SVG) is associated with a high risk of distal embolization and no reflow, since SVG lesions are often very friable and have a large thrombotic burden. We report a case of successful PPCI of the SVG using guide catheter thrombectomy with novel double wire technique.

Case summary

A 60-year-old male with a past history of coronary artery bypass grafting presented with acute thrombotic occlusion of the SVG to the obtuse marginal graft. Despite appropriate pharmacotherapy (GPIIb/IIIa inhibitors) and thrombosuction, there was a large residual thrombus burden with poor distal flow. In the present case, we decided to perform guide catheter thrombosuction. An exchange length floppy 0.014' wire was passed alongside the pre-existing wire and the 6 Fr JR guide catheter was exchanged for a less traumatic 5 Fr JR guide catheter over the exchange wire. The first wire was kept distally in the vessel along the guiding catheter to maintain the access to the graft vessel. The 5 Fr JR guide catheter was slowly advanced over the wire to the distal portion of the graft, keeping the other wire in the distal portion of the graft to maintain access. A large amount of thrombus was aspirated and the patient improved dramatically.

Discussion

This double wire technique is an effortless and novel way to maintain access to the distal vasculature of the occluded artery, while the guide can be safely intubated deep into the coronary artery that helps in removing a very large amount of thrombus because of their larger internal lumen.

The prognostic significance of single-lead ST-segment resolution in ST-segment elevation myocardial infarction patients treated with primary PCI - A substudy of the randomized TOTAL trial

BACKGROUND

ST-segment elevation myocardial infarction (STEMI) is associated with high morbidity and mortality worldwide. Simple electrocardiogram (ECG) tools, including ST-segment resolution (STR) have been developed to identify high-risk STEMI patients after primary percutaneous coronary intervention (PCI).

SUBJECTS AND METHODS

We evaluated the prognostic impact of STR in the ECG lead with maximal baseline ST-segment elevation (STE) 30-60 minutes after primary PCI in 7,654 STEMI patients included in the TOTAL trial. Incomplete or no STR was defined as < 70% STR and complete STR as ≥ 70% STR. The primary outcome was the composite of cardiovascular death, recurrent myocardial infarction (MI), cardiogenic shock, or new or worsening New York Heart Association (NYHA) class IV heart failure at 1-year follow-up.

RESULTS

Of 7,654 patients, 42.9% had incomplete or no STR and 57.1% had complete STR. The primary outcome occurred in 341 patients (10.4%) in the incomplete or no STR group and in 234 patients (5.4%) in the complete STR group. In Cox regression analysis, adjusted hazard ratio for STR < 70% to predict the primary outcome was 1.56 (95% confidence interval 1.32-1.89; P < .001) (model adjusted for all baseline comorbidities, clinical status during hospitalization, angiographic findings, and procedural techniques).

CONCLUSION

In a large international study of STEMI patients, STR < 70% 30-60 minutes post primary PCI in the ECG lead with the greatest STE at admission was associated with an increased rate of the composite of cardiovascular death, recurrent MI, cardiogenic shock, or new or worsening NYHA class IV heart failure at 1-year follow-up. Clinicians should pay attention to this simple ECG finding.

Index of Microcirculatory Resistance to predict microvascular obstruction in STEMI: A systematic review and meta-analysis

BACKGROUND

Microvascular obstruction (MVO) is an independent predictor of adverse cardiac events after ST-elevation myocardial infarction (STEMI). The Index of Microcirculatory Resistance (IMR) may be a useful marker of MVO, which could simplify the care pathway without the need for Cardiac Magnetic Resonance (CMR). We assessed whether the IMR can predict MVO in STEMI patients.

METHODS AND RESULTS

We conducted a systematic review and meta-analysis, including articles where invasive IMR was performed post primary percutaneous coronary intervention (PCI) in addition to MVO assessment with cardiac MRI. We searched PubMed, Scopus, Embase, and Cochrane databases from inception until January 2023. Baseline characteristics, coronary physiology and cardiac MRI data were extracted by two independent reviewers. The random-effects model was used to pool the data. Among 15 articles identified, nine articles (n = 728, mean age 61, 81% male) contained IMR data stratified by MVO. Patients with MVO had a mean IMR of 41.2 [95% CI 32.4-50.4], compared to 25.3 [18.3-32.2] for those without. The difference in IMR between those with and without MVO was 15.1 [9.7-20.6]. Meta-regression analyses demonstrated a linear relationship between IMR and TIMI grade (β = 0.69 [0.13-1.26]), as well as infarct size (β = 1.18 [0.24-2.11]) or ejection fraction at 6 months (β = -0.18 [-0.35 to -0.01]).

CONCLUSION

In STEMI, patients with MVO had 15-unit higher IMR than those without. IMR also predicts key prognostic endpoints such as infarct size, MVO, and long-term systolic function.

Design and rationale of the ATTRACTIVE trial: a randomised trial of intrAThrombus Thrombolysis versus aspiRAtion thrombeCTomy during prImary percutaneous coronary interVEntion in ST-segment elevation myocardial infarction patients with high thrombus burden

INTRODUCTION

ST-segment elevation myocardial infarction (STEMI) with high thrombus burden is associated with a poor prognosis. Manual aspiration thrombectomy reduces coronary vessel distal embolisation, improves microvascular perfusion and reduces cardiovascular deaths, but it promotes more strokes and transient ischaemic attacks in the subgroup with high thrombus burden. Intrathrombus thrombolysis (ie, the local delivery of thrombolytics into the coronary thrombus) is a recently proposed treatment approach that theoretically reduces thrombus volume and the risk of microvascular dysfunction. However, the safety and efficacy of intrathrombus thrombolysis lack sufficient clinical evidence.

METHODS AND ANALYSIS

The intrAThrombus Thrombolysis versus aspiRAtion thrombeCTomy during prImary percutaneous coronary interVEntion trial is a multicentre, prospective, open-label, randomised controlled trial with the blinded assessment of outcomes. A total of 2500 STEMI patients with high thrombus burden who undergo primary percutaneous coronary intervention will be randomised 1:1 to intrathrombus thrombolysis with a pierced balloon or upfront routine manual aspiration thrombectomy. The primary outcome will be the composite of cardiovascular death, recurrent myocardial infarction, cardiogenic shock, heart failure readmission, stent thrombosis and target-vessel revascularisation up to 180 days.

ETHICS AND DISSEMINATION

The trial was approved by Ethics Committees of China-Japan Friendship Hospital (2022-KY-013) and all other participating study centres. The results of this trial will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05554588.

Prognostic value and clinical usefulness of PIANO score in patients undergoing primary percutaneous coronary intervention

BACKGROUND

In our previous study, the PIANO score was constructed to predict the occurrence of no-reflow phenomenon in patients undergoing primary percutaneous coronary intervention (PCI). In the current analysis, we sought to evaluate the prognostic value and clinical usefulness of the PIANO score in this population.

METHODS

Patients with acute myocardial infarction (AMI) undergoing primary PCI were consecutively enrolled and followed up in this register. The endpoint of interest was all-cause mortality at 2 years after the procedure. The clinical benefits of thrombus aspiration (TA) during primary PCI in certain subgroups were also evaluated as exploratory analyses.

RESULTS

A total of 2100 patients were identified, and 54.3% had high (≥8) PIANO score. After 2-year follow-up, patients with high PIANO score had higher risk of all-cause mortality after adjustment for propensity score (6.7% vs. 3.1%, adjusted hazard ratio = 2.11 [1.21-3.68], p = 0.008), especially in the first month (adjusted hazard ratio = 2.33 [1.17-4.65], p = 0.017). Restricted cubic spline analysis indicated the linear association between the PIANO score and 2-year all-cause mortality (nonlinear p = 0.556). Further analysis demonstrated that TA did not reduce all-cause mortality in the overall patients, as well as in those with visible thrombus, high thrombus burden, or occlusive lesions. However, the PIANO score defined "high-risk" (PIANO score ≥ 8) patients could benefit from it.

CONCLUSIONS

The PIANO score had potential prognostic value in patients with AMI undergoing primary PCI. It might also be helpful for identifying patients who would benefit from TA. These observations require further confirmation in future studies.

Cardiovascular disease burden attributable to non-optimal temperature: analysis of the 1990-2019 global burden of disease

AIMS

Extreme temperatures are increasingly experienced as a result of climate change. Both high and low temperatures, impacted by climate change, have been linked with cardiovascular disease (CVD). Global estimates on non-optimal temperature-related CVD are not known. The authors investigated global trends of temperature-related CVD burden over the last three decades.

METHODS AND RESULTS

The authors utilized the 1990-2019 global burden of disease methodology to investigate non-optimal temperature, low temperature- and high temperature-related CVD deaths, and disability-adjusted life years (DALYs) globally. Non-optimal temperatures were defined as above (high temperature) or below (low temperature) the location-specific theoretical minimum-risk exposure level or the temperature associated with the lowest mortality rates. Analyses were later stratified by sociodemographic index (SDI) and world regions. In 2019, non-optimal temperature contributed to 1 194 196 (95% uncertainty interval [UI]: 963 816-1 425 090) CVD deaths and 21 799 370 (95% UI: 17 395 761-25 947 499) DALYs. Low temperature contributed to 1 104 200 (95% UI: 897 783-1 326 965) CVD deaths and 19 768 986 (95% UI: 16 039 594-23 925 945) DALYs. High temperature contributed to 93 095 (95% UI: 10 827-158 386) CVD deaths and 2 098 989 (95% UI: 146 158-3 625 564) DALYs. Between 1990 and 2019, CVD deaths related to non-optimal temperature increased by 45% (95% UI: 32-63%), low temperature by 36% (95% UI: 25-48%), and high temperature by 600% (95% UI: -1879-2027%). Non-optimal temperature- and high temperature-related CVD deaths increased more in countries with low income than countries with high income.

CONCLUSION

Non-optimal temperatures are significantly associated with global CVD deaths and DALYs, underscoring the significant impact of temperature on public health.

Direct Stenting versus Conventional Stenting in Patients with ST-Segment Elevation Myocardial Infarction-A COMPARE CRUSH Sub-Study

BACKGROUND

Direct stenting (DS) compared with conventional stenting (CS) after balloon predilatation may reduce distal embolization during percutaneous coronary intervention (PCI), thereby improving tissue reperfusion. In contrast, DS may increase the risk of stent underexpansion and target lesion failure.

METHODS

In this sub-study of the randomized COMPARE CRUSH trial (NCT03296540), we reviewed the efficacy of DS versus CS in a cohort of contemporary, pretreated ST-segment elevation myocardial infarction (STEMI) patients undergoing primary PCI. We compared DS versus CS, assessing (1) stent diameter in the culprit lesion, (2) thrombolysis in myocardial infarction (TIMI) flow in the infarct-related artery post-PCI and complete ST-segment resolution (STR) one-hour post-PCI, and (3) target lesion failure at one year. For proportional variables, propensity score weighting was applied to account for potential treatment selection bias.

RESULTS

This prespecified sub-study included 446 patients, of whom 189 (42%) were treated with DS. Stent diameters were comparable between groups (3.2 ± 0.5 vs. 3.2 ± 0.5 mm, p = 0.17). Post-PCI TIMI 3 flow and complete STR post-PCI rates were similar between groups (DS 93% vs. CS 90%, adjusted OR 1.16 [95% CI, 0.56-2.39], p = 0.69, and DS 72% vs. CS 58%, adjusted OR 1.29 [95% CI 0.77-2.16], p = 0.34, respectively). Moreover, target lesion failure rates at one year were comparable (DS 2% vs. 1%, adjusted OR 2.93 [95% CI 0.52-16.49], p = 0.22).

CONCLUSION

In this contemporary pretreated STEMI cohort, we found no difference in early myocardial reperfusion outcomes between DS and CS. Moreover, DS seemed comparable to CS in terms of stent diameter and one-year vessel patency.

Mitigating the risk of flow deterioration by deferring stent optimization in STEMI patients with large thrombus burden: Insights from a prospective cohort study

OBJECTIVES

It is uncertain, if omitting post-dilatation and stent oversizing (stent optimization) is safe and may decrease the risk for distal thrombus embolization (DTE) in STEMI patients with large thrombus burden (LTB).

BACKGROUND

In patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI) with stenting, (DTE) and flow deterioration are common and increase infarct size leading to worse outcomes.

METHODS

From a prospective registry, 74 consecutive STEMI patients with LTB undergoing pPCI with stenting and intentionally deferred stent optimization were analyzed. Imaging data and outcomes up to 2 years follow-up were analyzed.

RESULTS

Overall, 74 patients (18% females) underwent deferred stent optimization. Direct stenting was performed in 13 (18%) patients. No major complications occurred during pPCI. Staged stent optimization was performed after a median of 4 (interquartile range (IQR) 3; 7) days. On optical coherence tomography, under-expansion and residual thrombus were present in 59 (80%) and 27 (36%) cases, respectively. During deferred stent optimization, we encountered no case of flow deterioration (slow or no-reflow) or side branch occlusion. Minimal lumen area (mm2) and stent expansion (%) were corrected from 4.87±1.86mm to 6.82±2.36mm (p<0.05) and from 69±18% to 91±12% (p<0.001), respectively. During follow-up, 1 patient (1.4%) required target lesion revascularization and 1 (1.4%) patient succumbed from cardiovascular death.

CONCLUSIONS

Among STEMI patients with LTB, deferring stent optimization in the setting of pPCI appears safe and potentially mitigates the risk of DTE. The impact of this approach on infarct size and clinical outcomes warrants further investigation in a dedicated trial.

Review and Key Takeaways of the 2021 Percutaneous Coronary Intervention Guidelines

The 2021 Percutaneous Coronary Intervention guidelines completed by American College of Cardiology/American Heart Association/Society for Cardiovascular Angiography and Interventions provide a set of guidelines regarding revascularization strategies. With emphasis on equity of care, multidisciplinary heart team use, revascularization for acute coronary syndrome, and stable ischemic heart disease, the guidelines create a thorough framework with recommendations regarding therapeutic strategies. In this comprehensive review, our aim is to summarize the 2021 revascularization guidelines and analyze key points regarding each recommendation.

Microvascular Obstruction in Acute Myocardial Infarction, a Potential Therapeutic Target

Microvascular obstruction (MVO) is a recognised phenomenon following mechanical reperfusion in patients presenting with ST-segment elevation myocardial infarction (STEMI). Invasive and non-invasive modalities to detect and measure the extent of MVO vary in their accuracy, suggesting that this phenomenon may reflect a spectrum of pathophysiological changes at the level of coronary microcirculation. The importance of detecting MVO lies in the observation that its presence adds incremental risk to patients following STEMI treatment. This increased risk is associated with adverse cardiac remodelling seen on cardiac imaging, increased infarct size, and worse patient outcomes. This review provides an outline of the pathophysiology, clinical implications, and prognosis of MVO in STEMI. It describes historic and novel pharmacological and non-pharmacological therapies to address this phenomenon in conjunction with primary PCI.

Efficacy of thrombus aspiration in cardiogenic shock complicating acute myocardial infarction and high thrombus burden

INTRODUCTION AND OBJECTIVES

Current guidelines do not recommend routine thrombus aspiration in acute myocardial infarction (AMI) because no benefits were observed in previous randomized trials. However, there are limited data in cardiogenic shock (CS) complicating AMI.

METHODS

We included 575 patients with AMI complicated by CS. The participants were stratified into the TA and no-TA groups based on use of TA. The primary outcome was a composite of 6-month all-cause death or heart failure rehospitalization. The efficacy of TA was additionally assessed based on thrombus burden (grade I-IV vs V).

RESULTS

No significant difference was found in in-hospital death (28.9% vs 33.5%; P=.28), or 6-month death, or heart failure rehospitalization (32.4% vs 39.4%; HRadj: 0.80; 95%CI, 0.59-1.09; P=.16) between the TA and no-TA groups. However, in 368 patients with a higher thrombus burden (grade V), the TA group had a significantly lower risk of 6-month all-cause death or heart failure rehospitalization than the no-TA group (33.4% vs 46.3%; HRadj: 0.59; 95%CI, 0.41-0.85; P=.004), with significant interaction between thrombus burden and use of TA for primary outcome (adjusted Pint=.03).

CONCLUSIONS

Routine use of TA did not reduce short- and mid-term adverse clinical outcomes in patients with AMI complicated by CS. However, in select patients with a high thrombus burden, the use of TA might be associated with improved clinical outcomes. The study was registered at ClinicalTrials.gov (Identifier: NCT02985008).

The prognostic significance of Q waves and T wave inversions in the ECG of patients with STEMI: A substudy of the TOTAL trial

BACKGROUND

The prognostic significance of Q waves and T-wave inversions (TWI) combined and separately in STEMI patients undergoing primary PCI has not been well established in previous studies.

METHODS

We included 7,831 patients from the TOTAL trial and divided the patients into categories based on Q waves and TWIs in the presenting ECG. The primary outcome was a composite of cardiovascular death, recurrent myocardial infarction (MI), cardiogenic shock or new or worsening NYHA class IV heart failure within one year. The study evaluated the effect of Q waves and TWI on the risk of primary outcome and all-cause death, and whether patient benefit of aspiration thrombectomy differed between the ECG categories.

RESULTS

Patients with Q+TWI+ (Q wave and TWI) pattern had higher risk of primary outcome compared to patients with Q-TWI- pattern [33 (10.5%) vs. 221 (4.2%); adjusted hazard ratio (aHR) 2.10; 95% CI, 1.45-3.04; p<0.001] within 40-days' period. When analyzed separately, patients with Q waves had a higher risk for the primary outcome compared to patients with no Q waves in the first 40 days [aHR 1.80; 95% CI, 1.48-2.19; p<0.001] but there was no additive risk after 40 days. Patients with TWI had a higher risk for primary outcome only after 40 days when compared to patients with no TWI [aHR 1.63; 95% CI, 1.04-2.55; p=0.033]. There was a trend towards a benefit of thrombectomy in patients with the Q+TWI+ pattern.

CONCLUSIONS

Q waves and TWI combined (Q+TWI+ pattern) in the presenting ECG is associated with unfavourable outcome within 40-days. Q waves tend to affect short-term outcome, while TWI has more effect on long-term outcome.

Upstream anticoagulation in patients with ST-segment elevation myocardial infarction: a systematic review and meta-analysis

BACKGROUND AND AIM

Parenteral anticoagulation is recommended for all patients presenting with ST-segment elevation myocardial infarction (STEMI) during primary percutaneous coronary intervention (PPCI). Whether upstream anticoagulation improves clinical outcomes is not well established. We conducted a systematic review and meta-analysis of contemporary evidence on parenteral anticoagulation timing for STEMI patients.

METHODS

We performed a systematic search of electronic databases (PubMed, CENTRAL, and Scopus) until December 2022. Studies were eligible if they (a) compared upstream anticoagulation with administration at the catheterization laboratory and (b) enrolled patients with STEMI undergoing PPCI. Efficacy outcomes included in-hospital or 30-day mortality, in-hospital cardiogenic shock (CS), and TIMI flow grade pre- and post-PPCI. Safety outcome was defined as in-hospital or 30-day major bleeding.

RESULTS

Overall, seven studies were included (all observational), with a total of 69,403 patients. Upstream anticoagulation was associated with a significant reduction in the incidence of in-hospital or 30-day all-cause mortality (OR 0.61; 95% CI 0.45-0.81; p < 0.001) and in-hospital CS (OR 0.68; 95% CI 0.58-0.81; p < 0.001) and with an increase in spontaneous reperfusion (pre-PPCI TIMI > 0: OR 1.46; 95% CI 1.35-1.57; p < 0.001). Pretreatment was not associated with an increase in major bleeding (OR 1.02; 95% CI 0.70-1.48; p = 0.930).

CONCLUSIONS

Upstream anticoagulation was associated with a significantly lower risk of 30-day all-cause mortality, incidence of in-hospital CS, and improved reperfusion of the infarct-related artery (IRA). These findings were not accompanied by an increased risk of major bleeding, suggesting an overall clinical benefit of early anticoagulation in STEMI. These results require confirmation in a dedicated randomized clinical trial.

Coronary No-Reflow after Primary Percutaneous Coronary Intervention-Current Knowledge on Pathophysiology, Diagnosis, Clinical Impact and Therapy

Coronary no-reflow (CNR) is a frequent phenomenon that develops in patients with ST-segment elevation myocardial infarction (STEMI) following reperfusion therapy. CNR is highly dynamic, develops gradually (over hours) and persists for days to weeks after reperfusion. Microvascular obstruction (MVO) developing as a consequence of myocardial ischemia, distal embolization and reperfusion-related injury is the main pathophysiological mechanism of CNR. The frequency of CNR or MVO after primary PCI differs widely depending on the sensitivity of the tools used for diagnosis and timing of examination. Coronary angiography is readily available and most convenient to diagnose CNR but it is highly conservative and underestimates the true frequency of CNR. Cardiac magnetic resonance (CMR) imaging is the most sensitive method to diagnose MVO and CNR that provides information on the presence, localization and extent of MVO. CMR imaging detects intramyocardial hemorrhage and accurately estimates the infarct size. MVO and CNR markedly negate the benefits of reperfusion therapy and contribute to poor clinical outcomes including adverse remodeling of left ventricle, worsening or new congestive heart failure and reduced survival. Despite extensive research and the use of therapies that target almost all known pathophysiological mechanisms of CNR, no therapy has been found that prevents or reverses CNR and provides consistent clinical benefit in patients with STEMI undergoing reperfusion. Currently, the prevention or alleviation of MVO and CNR remain unmet goals in the therapy of STEMI that continue to be under intense research.

Outcomes of thrombus aspiration during primary percutaneous coronary intervention for ST-elevation myocardial infarction

BACKGROUND

Previous large multi-centre randomised controlled trials have not provided clear benefit with routine intracoronary thrombus aspiration (TA) as an adjunct to primary percutaneous coronary intervention (PCI) in patients with ST-elevation myocardial infarction (STEMI).

AIM

To determine whether there is a difference in outcomes with the use of manual TA prior to PCI, compared with PCI alone in a cohort of patients with STEMI.

METHODS

We analysed data from 6270 consecutive patients undergoing primary PCI for STEMI prospectively enrolled in the Melbourne Interventional Group registry between 2007 and 2018. Multivariable analysis was performed to determine predictors of 30-day major adverse cardiovascular and cerebrovascular events (MACCE) and long-term mortality.

RESULTS

We compared 1621 (26%) patients undergoing primary PCI with TA to 4649 (74%) patients undergoing PCI alone. Male gender (81% vs 78%; P < 0.01), younger age (61 vs 63 years; P = 0.03), GP-IIb/IIIa use (76% vs 58%, P < 0.01), and current smoking (40% vs 36%; P < 0.01) were more common in the TA group. TA was more likely to be used in patients with complex lesions (83% vs 66%; P < 0.01) with TIMI 0 flow (77% vs 56%; P < 0.01). No significant difference in post-procedural TIMI flow, stroke, 30-day mortality, or long-term mortality were identified. Multivariable analysis demonstrated a reduction in 30-day MACCE (hazard ratio (HR) 0.75; confidence interval (CI) 0.63-0.89; P < 0.01) in the TA group, but was not associated with long-term mortality (HR 0.98; CI 0.85-1.1; P = 0.73).

CONCLUSION

The use of TA in patients undergoing primary PCI for STEMI was not associated with improved short or long-term mortality when compared with PCI alone.

Prepercutaneous coronary intervention Zalunfiban dose-response relationship to target vessel blood flow at initial angiogram in st-elevation myocardial infarction - A post hoc analysis of the cel-02 phase IIa study

BACKGROUND

Zalunfiban (RUC-4) is a novel, subcutaneously administered glycoprotein IIb/IIIa inhibitor (GPI) designed for prehospital treatment to initiate reperfusion in the infarct-related artery (IRA) before primary percutaneous coronary intervention in patients with ST-elevation myocardial infarction (STEMI). Since GPIs have been reported to rapidly reperfuse IRAs, we assessed whether there was a dose-dependent relationship between zalunfiban treatment and angiographic reperfusion indices and thrombus grade of the IRA at initial angiogram in patients with STEMI.

METHODS

This was a post hoc analysis from the open-label Phase IIa study that investigated the pharmacodynamics, pharmacokinetics, and tolerability of three doses of zalunfiban - 0.075, 0.090 and 0.110 mg/kg - in STEMI patients. This analysis explored dose-dependent associations between zalunfiban and three angiographic indices of the IRA, namely coronary and myocardial blood flow and thrombus burden. Zalunfiban was administered in the cardiac catheterization laboratory prior to vascular access, ∼10 to 15 minutes before the initial angiogram. All angiographic data were analyzed by a blinded, independent, core laboratory.

RESULTS

Twentyfour out of 27 STEMI patients were evaluable for angiographic analysis (0.075 mg/kg [n=7], 0.090 mg/kg [n=9], and 0.110 mg/kg [n=8]). TIMI flow grade 2 or 3 was seen in 1/7 patients receiving zalunfiban at 0.075 mg/kg, in 6/9 patients receiving 0.090 mg/kg, and in 7/8 patients receiving 0.110 mg/kg (ptrend = 0.004). A similar trend was observed based on TIMI flow grade 3. Myocardial perfusion was also related to zalunfiban dose (ptrend = 0.005) as reflected by more frequent TIMI myocardial perfusion grade 3. Consistent with the dose-dependent trends in greater coronary and myocardial perfusion, TIMI thrombus ≥4 grade was inversely related to zalunfiban dose (ptrend = 0.02).

CONCLUSION

This post hoc analysis found that higher doses of zalunfiban administered in the cardiac catheterization lab prior to vascular access were associated with greater coronary and myocardial perfusion, and lower thrombus burden at initial angiogram in patients with STEMI undergoing primary percutaneous coronary intervention.

Temporal Trends in Infarct Severity Outcomes in ST-Segment-Elevation Myocardial Infarction: A Cardiac Magnetic Resonance Imaging Study

Background Severity of myocardial tissue injury is a main determinant of morbidity and death related to ST-segment-elevation myocardial infarction (STEMI). Temporal trends of infarct characteristics at the myocardial tissue level have not been described. This study sought to assess temporal trends in infarct characteristics through a comprehensive assessment by cardiac magnetic resonance imaging at a standardized time point early after STEMI. Methods and Results We analyzed patients with STEMI treated with percutaneous coronary intervention at the University Hospital of Innsbruck who underwent cardiac magnetic resonance imaging between 2005 and 2021. The study period was divided into terciles. Myocardial damage characteristics were assessed using a multiparametric cardiac magnetic resonance imaging protocol within the first week after STEMI and compared between groups. A total of 843 patients with STEMI (17% women) with a median age of 57 (interquartile range, 51-66) years were analyzed. While age, sex, and the clinical risk profile expressed as thrombolysis in myocardial infarction risk score were comparable across the study period, there were differences in guideline-recommended therapies. At the same time, there was no significant change in infarct size (P=0.25), microvascular obstruction (P=0.50), and intramyocardial hemorrhage (P=0.34). Left ventricular remodeling indices and left ventricular ejection fraction remained virtually unchanged (all P>0.05). Major adverse cardiovascular events at 4 (interquartile range, 4-5) months were similar between groups (P=0.36). Conclusions In this magnetic resonance imaging study investigating patients with STEMI treated with primary percutaneous coronary intervention over the past 15 years, no change in infarct severity at the myocardial level has been observed. Clinical research on novel therapeutic approaches to reduce myocardial tissue injury should be a priority.

Aspiration thrombectomy: safe removal of thrombi too big to aspirate

Aspiration thrombectomy has been associated with an increased risk of stroke, and its routine use is not recommended. Ill-defined procedural techniques for aspiration thrombectomy may provide an explanation for inconsistent outcomes and adverse event rates in trials. Large thrombi can plug the aspiration port of the aspiration catheter and then be dislodged into the central circulation when they are retracted into the guide catheter, or when the aspiration catheter is removed from the Tuohy connector. We report a case of thrombus aspiration where a large distal thrombus was aspirated into the mouth of the aspiration catheter, held there with suction as it was removed and delivered outside the body without being dislodged. We offer several tips for safe removal of coronary thrombi too big to aspirate.

Thrombus containing lesions strategies during primary percutaneous coronary interventions in ST-segment elevation myocardial infarction: insights from ORPKI National Registry

In the era of potent P2Y₁₂ inhibitors, according to current guidelines, treatment with glycoprotein IIb/IIIa inhibitors (GPIs) should be limited to bail-out and/or highly thrombotic situations. Similarly, the recommendation for aspiration thrombectomy (AT) is downgraded to very selective use. We examine the prevalence, and predictors of GPI and AT use in STEMI patients referred to primary percutaneous coronary intervention (PCI). Data on 116,873 consecutive STEMI patients referred to primary PCI in Poland between 2015 and 2020 were analyzed. GPIs were administered in 29.3%, AT was used in 11.6%, and combined treatment with both in 6.1%. There was a mild trend toward a decrease in GPI and AT usage during the analyzed years. On the contrary, there was a rapid growth of the ticagrelor/prasugrel usage rate from 6.5 to 48.1%. Occluded infarct-related artery at baseline and no-reflow during PCI were the strongest predictors of GPI administration (OR 2.3; 95% CI 2.22-2.38 and OR 3.47; 95% CI 3.13-3.84, respectively) and combined usage of GPI and AT (OR 4.4; 95% CI 4.08-4.8 and OR 3.49; 95% CI 3.08-3.95 respectively) in a multivariate logistic regression model. Similarly, the administration of ticagrelor/prasugrel was an independent predictor of both adjunctive treatment strategies. In STEMI patients in Poland, GPIs are selectively used in one in four patients during primary PCI, and the combined usage of GPI and AT is marginal. Despite the rapid growth in potent P2Y₁₂ inhibitors usage in recent years, GPIs are selectively used at a stable rate during PCI in highly thrombotic lesions.

Institutional Variance in Mortality after Percutaneous Coronary Intervention for Acute Myocardial Infarction in Korea, Japan, and Taiwan

BACKGROUND

Although there have been studies that compared outcomes of patients with acute myocardial infarction (AMI) across countries, little focus has been placed on institutional variance of outcomes. The aim of the present study was to compare institutional variance in mortality following percutaneous coronary intervention (PCI) for AMI and factors explaining this variance across different health systems.

METHODS

Data on inpatients who underwent PCI for AMI in 2016 were obtained from the National Health Insurance Data Sharing Service in Korea, the Diagnosis Procedure Combination (DPC) Study Group Database in Japan, and the National Health Insurance Research Database (NHIRD) in Taiwan. Multilevel analyses with inpatient mortality as the outcome and the hierarchical structure of patients nested within hospitals were conducted, adjusting for common patient-level and hospital-level variables. We compared the intraclass correlation coefficient (ICC) and the proportion of variance explained by hospital-level characteristics across the three health systems.

RESULTS

There were 17 351 patients from 160 Korean hospitals, 29 804 patients from 660 Japanese hospitals, and 10 863 patients from 104 Taiwanese hospitals included in the analysis. Inpatient mortality rates were 6.3%, 7.3%, and 6.0% in Korea, Japan, and Taiwan, respectively. After adjusting for patient and hospital characteristics, Taiwan had the lowest variation in mortality (ICC, 1.8%), followed by Korea (2.2%) and then Japan (4.5%). The measured hospital characteristics explained 38%, 19%, and 9% of the institutional variance in Korea, Taiwan, and Japan, respectively.

CONCLUSION

Korea, Japan, and Taiwan had similarly uniform outcomes across hospitals for patients undergoing PCI for AMI. However, Japan had a relatively large institutional variance in mortality and a lower proportion of variation explainable by hospital characteristics, compared with Korea and Taiwan.

Thrombus burden management during primary coronary bifurcation intervention: a new experimental bench model

BACKGROUND

Management of thrombus burden during primary percutaneous coronary intervention (pPCI) is a key-point, given the high risk of stent malapposition and/or thrombus embolization. These issues are especially important if pPCI involves a coronary bifurcation. Herein, a new experimental bifurcation bench model to analyze thrombus burden behavior was developed.

METHODS

On a fractal left main bifurcation bench model, we generated standardized thrombus with human blood and tissue factor. Three provisional pPCI strategies were compared (n = 10/group): 1) balloon-expandable stent (BES), 2) BES completed by proximal optimizing technique (POT), and 3) nitinol self-apposing stent (SAS). The embolized distal thrombus after stent implantation was weighed. Stent apposition and thrombus trapped by the stent were quantified on 2D-OCT. To analyze final stent apposition, a new OCT acquisition was performed after pharmacological thrombolysis.

RESULTS

Trapped thrombus was significantly greater with isolated BES than SAS or BES+POT (18.8 ± 5.8% vs. 10.3 ± 3.3% and 6.2 ± 2.1%, respectively; p < 0.05), and greater with SAS than BES+POT (p < 0.05). Isolated BES and SAS tended show less embolized thrombus than BES+POT (5.93 ± 4.32 mg and 5.05 ± 4.56 mg vs. 7.01 ± 4.32 mg, respectively; p = NS). Conversely, SAS and BES+POT ensured perfect final global apposition (0.4 ± 0.6% and 1.3 ± 1.3%, respectively, p = NS) compared to isolated BES (74.0 ± 7.6%, p < 0.05).

CONCLUSIONS

This first experimental bench model of pPCI in a bifurcation quantified thrombus trapping and embolization. BES provided the best thrombus trapping, while SAS and BES+POT achieved better final stent apposition. These factors should be taken into account in selecting revascularization strategy.

Safety and efficacy of intracoronary thrombolytic agents during primary percutaneous coronary intervention for STEMI

INTRODUCTION

Large thrombus burden in patients with ST elevation myocardial infarction (STEMI) is associated with higher rates of distal embolization, no-reflow phenomenon, abrupt closure, stent thrombosis, major adverse cardiovascular events (MACE), and mortality. Intracoronary (IC) thrombolytic agents are theoretically attractive as an adjunct to primary percutaneous coronary intervention (PPCI) as they activate endogenous fibrinolysis which results in degradation of the cross-linked fibrin matrix in coronary thrombus.

AREAS COVERED

We reviewed published studies reporting on intraprocedural anti-thrombus strategies used during PPCI including randomized controlled trials and observational studies.

EXPERT OPINION

Published studies are limited by small sample size and heterogeneity due to variation in indication, inclusion criteria, thrombolytic agent, dose, delivery mechanisms, antiplatelet and anticoagulant regimen, timing in regard to reperfusion, PCI techniques, and endpoints. Despite these limitations, data are consistent that IC administration of thrombolytic agents at low doses is associated with low rates of bleeding and vascular complications. While there is currently no compelling data demonstrating a benefit to the routine use of IC thrombolytic therapy in patients with STEMI, there is suggestive data that IC thrombolysis may have benefit in selected patients.

Sustained Mechanical Aspiration Thrombectomy for High Thrombus Burden Coronary Vessel Occlusion: The Multicenter CHEETAH Study

BACKGROUND

Poor myocardial reperfusion due to distal embolization and microvascular obstruction after percutaneous coronary intervention is associated with increased risk of morbidity and mortality. Prior trials have not shown a clear benefit of routine manual aspiration thrombectomy. Sustained mechanical aspiration may mitigate this risk and improve outcomes. The objective of this study is to evaluate sustained mechanical aspiration thrombectomy before percutaneous coronary intervention in high thrombus burden acute coronary syndrome patients.

METHODS

This prospective study evaluated the Indigo CAT RX Aspiration System (Penumbra Inc, Alameda CA) for sustained mechanical aspiration thrombectomy before percutaneous coronary intervention at 25 hospitals across the USA. Adults presenting within 12 hours of symptom onset with high thrombus burden and target lesion(s) located in a native coronary artery were eligible. The primary end point was a composite of cardiovascular death, recurrent myocardial infarction, cardiogenic shock, or new or worsening New York Heart Association class IV heart failure within 30 days. Secondary end points included Thrombolysis in Myocardial Infarction thrombus grade, Thrombolysis in Myocardial Infarction flow, myocardial blush grade, stroke, and device-related serious adverse events.

RESULTS

From August 2019 through December 2020, a total of 400 patients were enrolled (mean age 60.4 years, 76.25% male). The primary composite end point rate was 3.60% (14/389 [95% CI, 2.0-6.0%]). Rate of stroke within 30 days was 0.77%. Final rates of Thrombolysis in Myocardial Infarction thrombus grade 0, Thrombolysis in Myocardial Infarction flow 3, and myocardial blush grade 3 were 99.50%, 97.50%, and 99.75%, respectively. No device-related serious adverse events occurred.

CONCLUSIONS

Sustained mechanical aspiration before percutaneous coronary intervention in high thrombus burden acute coronary syndrome patients was safe and was associated with high rates of thrombus removal, flow restoration, and normal myocardial perfusion on final angiography.

A rare mechanism of embolic stroke complicating coronary thrombus aspiration

Aspiration thrombectomy is often performed in patients with acute myocardial infarction with high thrombus burden. Current guidelines, however, recommend against it because of stroke risk. We report a case of embolic stroke complicating coronary thrombus aspiration in a 62-year-old man. Aspiration thrombectomy during percutaneous coronary intervention migrated thrombus to the proximal right coronary artery (RCA), and the thrombus was subsequently released into the aorta by backflow of the contrast injection causing aspiration thrombectomy-associated stroke. This is an extremely rare mechanism by which complications arise from failed aspiration thrombectomy.

In Vitro Comparison of Several Thrombus Removal Tools

BACKGROUND

Although the routine use of thrombus aspiration is not recommended, the thrombectomy technique still might be considered for a selected population of patients. Therefore, the assessment of the effectiveness of commercially available thrombectomy devices is still clinically relevant.

AIM

Here, we present an in vitro comparison of several different types of catheters that can be used for thrombus aspiration or removal.

METHODS

Through the removal of 6 h and 24 h human blood clots in an in vitro model, four catheters were compared: the Launcher, Pronto V4, Vasco+ and the stent-retriever Catchview. The aspiration efficacy was expressed as a percentage of the initial thrombus weight. The effectiveness of the patient's aspiration was dependent on the time of thrombus formation and was significantly higher for a thrombus formed over 24 h (58.5 ± 26.5%) than for one formed over 6 h (48.0 ± 22.5%; p < 0.001). In the presented in vitro model, Pronto V4 and Launcher showed the highest efficiency.

CONCLUSIONS

Large-bore aspiration catheters were found to be more effective than narrow-bore catheters or stent-retrievers in an in vitro model of thrombus removal. The thrombus aspiration efficacy increases with longer thrombus formation times.

Benefits of excimer laser coronary angioplasty over thrombus aspiration therapy for patients with acute coronary syndrome and thrombolysis in myocardial infarction flow grade 0

In primary percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS), the presence of a thrombus or unstable plaque can cause microvascular obstructions, which may increase infarct size and reduce survival. Excimer laser coronary angioplasty (ELCA) is a unique revascularization technique that can vaporize plaques and thrombi. However, to date, only few reports indicate the efficacy of ELCA for ACS. We retrospectively analyzed 113 consecutive ACS patients who underwent PCI with either ELCA or manual thrombus aspiration therapy (TA) before balloon angioplasty or stenting and who had a Thrombolysis in Myocardial Infarction flow (TIMI) grade 0 on the first contrast injection within 24 h of onset at our hospital from March 2011 to March 2020. Patients were divided into two groups by the procedure used: ELCA (N = 48) and TA (N = 50). Door-to-reperfusion time was significantly shorter in the ELCA group than TA group (89.2 ± 6.7 vs. 137.9 ± 12.3 min, respectively; P < 0.01). There was also a significant difference in peak creatine kinase-myocardial band between the ELCA and TA groups (242 ± 25 vs. 384 ± 63 IU/L, respectively; P = 0.04). Although there was no difference in myocardial blush grade (MBG) before treatment, the MBG after treatment was higher in the ELCA group (P < 0.01). In-hospital major adverse cardiac events (MACE) were also significantly fewer in the ELCA group than in the TA group (8% vs. 20%, P = 0.045). ELCA for TIMI grade 0 ACS may shorten reperfusion time, improve the MBG score, and reduce MACE when compared to TA.

Dual Role of Guide Extension Catheters for the Management of High Thrombus Burden in STEMI: Case Report and Mini Review

High thrombus burden in ST segment elevation myocardial infarction (STEMI) patients increases the risk of adverse events. In this report, we review current strategies for high thrombus burden and present a case report with the combination of two different techniques: aspiration through a guide extension catheter followed by local intracoronary thrombolysis with 'marinade' technique.

Sex-Related Differences in Thrombus Burden in STEMI Patients Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND

Women have a worse prognosis after ST-segment elevation myocardial infarction (STEMI) than men. The prognostic role of thrombus burden (TB) in influencing the sex-related differences in clinical outcomes after STEMI has not been clearly investigated.

OBJECTIVES

The aim of this study was to assess the sex-related differences in TB and its clinical implications in patients with STEMI.

METHODS

Individual patient data from the 3 major randomized clinical trials of manual thrombus aspiration were analyzed, encompassing a total of 19,047 patients with STEMI, of whom 13,885 (76.1%) were men and 4,371 (23.9%) were women. The primary outcome of interest was 1-year cardiovascular (CV) death. The secondary outcomes of interest were recurrent myocardial infarction, heart failure, all-cause mortality, stroke, stent thrombosis (ST), and target vessel revascularization at 1 year.

RESULTS

Patients with high TB (HTB) had worse 1-year outcomes compared with those presenting with low TB (adjusted HR for CV death: 1.52; 95% CI: 1.10-2.12; P = 0.01). In unadjusted analyses, female sex was associated with an increased risk for 1-year CV death regardless of TB. After adjustment, the risk for 1-year CV death was higher only in women with HTB (HR: 1.23; 95% CI: 1.18-1.28; P < 0.001), who also had an increased risk for all-cause death and ST than men.

CONCLUSIONS

In patients with STEMI, angiographic evidence of HTB negatively affected prognosis. Among patients with HTB, women had an excess risk for ST, CV, and all-cause mortality than men. Further investigations are warranted to better understand the pathophysiological mechanisms leading to excess mortality in women with STEMI and HTB.

Management of Coronary Complications

Coronary complications are increasingly rare but remain fatal if not managed promptly and effectively. We review the incidence, management, and prevention of the most serious coronary complications including acute vessel closure from dissection, no-reflow, thrombosis, and air embolism as well as mechanical complications including perforation, stent dislodgment, and atherectomy burr entrapment.

Primary Percutaneous Coronary Intervention and Application of the Pharmacoinvasive Approach Within ST-Elevation Myocardial Infarction Care Networks

The management of acute ST-elevation myocardial infarction (STEMI) has transitioned from observation and reactive treatment of hemodynamic and arrhythmic complications to accelerated reperfusion and application of evidence-based treatment to minimize morbidity and mortality. International research established the importance of timely reperfusion therapy and the application of fibrinolysis, primary percutaneous coronary intervention (PCI), and subsequent development of the pharmacoinvasive approach. Clinician thought leaders developed and investigated comprehensive systems of care to optimize the outcomes of patients with STEMI, with a key focus in Canada being the integration of prehospital paramedics in diagnosis, triage, and treatment. This article will review highlights of these interventions and identify future challenges and opportunities in STEMI patient care.

Intracoronary eptifibatide with vasodilators to prevent no-reflow in diabetic STEMI with high thrombus burden. A randomized trial

INTRODUCTION AND OBJECTIVES

To study the impact of injecting intracoronary eptifibatide plus vasodilators via thrombus aspiration catheter vs thrombus aspiration alone in reducing the risk of no-reflow in acute ST-elevation myocardial infarction (STEMI) with diabetes and high thrombus burden.

METHODS

The study involved 413 diabetic STEMI patients with high thrombus burden, randomized to intracoronary injection (distal to the occlusion) of eptifibatide, nitroglycerin and verapamil after thrombus aspiration and prior to balloon inflation (n=206) vs thrombus aspiration alone (n=207). The primary endpoint was post procedural myocardial blush grade and corrected Thrombolysis in Myocardial Infarction (TIMI) frame count (cTFC). Major adverse cardiovascular events were reported at 6 months.

RESULTS

The intracoronary eptifibatide and vasodilators arm was superior to thrombus aspiration alone regarding myocardial blush grade-3 (82.1% vs 31.4%; P=.001). The local intracoronary eptifibatide and vasodilators arm had shorter cTFC (18.16±6.54 vs 29.64±5.53, P=.001), and better TIMI 3 flow (91.3% vs 61.65%; P=.001). Intracoronary eptifibatide and vasodilators improved ejection fraction at 6 months (55.2±8.13 vs 43±6.67; P=.005). There was no difference in the rates of major adverse cardiovascular events at 6 months.

CONCLUSIONS

Among diabetic patients with STEMI and high thrombus burden, intracoronary eptifibatide plus vasodilators injection was beneficial in preventing no-reflow compared with thrombus aspiration alone. Larger studies are encouraged to investigate the benefit of this strategy in reducing the risk of adverse clinical events.

Successful visible thrombus aspiration in ST-segment elevation myocardial infarction: associated factors and the clinical impact

BACKGROUND

Thrombus aspiration (TA) has been considered a procedure for controlling distal emboli and improving microvascular perfusion. However, current guidelines classify routine TA as class III recommendation, and it has been reported that the efficacy of TA is limited because of the relatively high incidence of failure in retrieval of thrombotic material. The aim of this study was to explore patient characteristics and procedural factors associated with successful TA in ST-elevation myocardial infarction (STEMI) and to assess the clinical impact of successful TA.

METHODS

This single-center retrospective study enrolled 158 STEMI patients who underwent TA as initial recanalization. Factors associated with successful TA, which was defined as retrieving any visible material by aspiration catheter, were explored, and angiographical and short-term outcomes were assessed.

RESULTS

In 146 cases (92.4%), the aspiration catheter reached the culprit lesion. Successful TA was achieved in 72 cases (45.6%). The single angiographical characteristic of successful TA was a higher Thrombolysis in Myocardial Infarction grade before TA. Among the procedural characteristics, the rate of successful TA was higher with a 7-French aspiration catheter compared with the rate with a 6-French catheter (57.1% vs. 29.9%, P  = 0.01). Thrombolysis in Myocardial Infarction grade 3 flow was more frequent in patients with successful TA immediately after TA (36.1% vs. 16.3%, P  = 0.006) and at final angiography (91.7% vs 79.1%, P  = 0.04) compared with the grade in patients without successful TA, respectively.

CONCLUSIONS

The use of a larger aspiration catheter may be effective in retrieving visible thrombus material, and successful TA led to better angiographical results.

Effect of direct stenting on microvascular dysfunction during percutaneous coronary intervention in acute myocardial infarction: a randomized pilot study

Objective

Whether direct stenting (DS) without predilatation during primary percutaneous coronary intervention (PPCI) reduces microvascular dysfunction in patients with ST-elevation myocardial infarction is unclear. We performed a randomized study to assess the effect of DS on microvascular reperfusion.

Methods

Seventy-two patients undergoing PPCI were randomly assigned to the DS or conventional stenting (CS) with predilatation groups. The primary endpoint was the post-PPCI index of microcirculatory resistance (IMR). We compared thrombolysis in myocardial infarction myocardial perfusion (TMP) grades, ST-segment resolution, and long-term clinical outcomes between the groups.

Results

Microvascular reperfusion parameters immediately after PPCI (e.g., the IMR, TMP grade, and ST-segment resolution) were not different between the groups. However, significantly fewer patients in the DS group had the IMR measured because of no-reflow or cardiogenic shock during PPCI than those in the CS group. No differences were found in left ventricular functional recovery or clinical outcomes between the groups.

Conclusions

This trial showed no effect of DS on the IMR. However, our finding should be interpreted with caution because the number of patients who could not have the IMR measured was higher in the CS group than in the DS group. A larger randomized trial is required (Research Registry number: 8079).