Thrombus Aspiration in ST-Segment-Elevation Myocardial Infarction: An Individual Patient Meta-Analysis: Thrombectomy Trialists Collaboration

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.

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.

Association Between Platelet Glycoprotein IIb/IIIa Inhibition and In-Hospital Outcomes in ST-Elevation Myocardial Infarction Patients Treated with Coronary Thrombus Aspiration: Findings from the CCC-ACS Project

PURPOSE

Thrombus aspiration in ST-elevation myocardial infarction (STEMI) with high thrombus burden did not improve clinical outcomes. The clinical efficacy of the bailout use of platelet glycoprotein IIb/IIIa inhibitors (GPIs) in this clinical scenario remains unknown.

METHODS

We assessed associations between GPI use and in-hospital major bleeds, ischemic events, and mortality among STEMI patients treated with percutaneous coronary intervention (PCI) and thrombus aspiration in a nationwide acute coronary syndrome registry (the Improving Care for Cardiovascular Disease in China-Acute Coronary Syndrome project).

RESULTS

A total of 5896 STEMI patients who received thrombus aspiration were identified, among which 56.3% received GPI therapy. In a 1-to-1 propensity-score-matched cohort, compared with STEMI patients not treated with GPI, GPI use was associated with a 69% increase in major in-hospital bleeds, with an odds ratio (OR) of 1.69, a 95% confidence interval (CI) of 1.08 to 2.65, and a nonsignificant reduction in ischemic events (OR: 0.61, 95% CI: 0.36 to 1.06), as well as a neutral effect on mortality (OR: 0.93, 95% CI: 0.55 to 1.58). However, among patients aged < 60 years, GPI use was associated with a reduction in ischemic events (OR: 0.27, 95% CI: 0.08 to 0.98), and no significant increase in major bleeds was observed.

CONCLUSION

In a nationwide registry, routine use of GPI following thrombus aspiration was not associated with reduced in-hospital ischemic events and mortality but at the cost of increased major bleeding. However, for patients aged < 60 years, there may be a potential net benefit.

In situ formed depot of elastin-like polypeptide-hirudin fusion protein for long-acting antithrombotic therapy

Thrombosis, induced by abnormal coagulation or fibrinolytic systems, is the most common pathology associated with many life-threatening cardio-cerebrovascular diseases. However, first-line anticoagulant drugs suffer from rapid drug elimination and risk of hemorrhagic complications. Here, we developed an in situ formed depot of elastin-like polypeptide (ELP)-hirudin fusion protein with a prodrug-like feature for long-term antithrombotic therapy. Highly secretory expression of the fusion protein was achieved with the assistance of the Ffu312 tag. Integration of hirudin, ELP, and responsive moiety can customize fusion proteins with properties of adjustable in vivo retention and controllable recovery of drug bioactivity. After subcutaneous injection, the fusion protein can form a reservoir through temperature-induced coacervation of ELP and slowly diffuse into the blood circulation. The biological activity of hirudin is shielded due to the N-terminal modification, while the activated key proteases upon thrombus occurrence trigger the cleavage of fusion protein together with the release of hirudin, which has antithrombotic activity to counteract thrombosis. We substantiated that the optimized fusion protein produced long-term antithrombotic effects without the risk of bleeding in multiple animal thrombosis models.

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.

Determinants and Prognoses of Visual-Functional Mismatches After Mechanical Reperfusion in ST-Elevation Myocardial Infarction

Background

Discordance between the anatomy and physiology of the coronary has important implications for managing patients with stable coronary disease, but its significance in ST-elevation myocardial infarction has not been fully elucidated.

Methods

The retrospective study involved patients diagnosed with ST-elevation myocardial infarction (STEMI) who underwent percutaneous coronary intervention (PCI), along with quantitative coronary angiography (QCA) and quantitative flow ratio (QFR) assessments. Patients were stratified into four groups regarding the severity of the culprit vessel, both visually and functionally: concordantly negative (QCA-diameter stenosis [DS] ≤ 50% and QFR > 0.80), mismatch (QCA-DS > 50% and QFR > 0.80), reverse mismatch (QCA-DS ≤ 50% and QFR ≤ 0.80), and concordantly positive (QCA-DS > 50% and QFR ≤ 0.80). Multivariable logistic regression analyses were conducted to identify the clinical factors linked to visual-functional mismatches. Kaplan‒Meier analysis was conducted to estimate the 18-month adverse cardiovascular events (MACE)-free survival between the four groups.

Results

The study involved 310 patients, with 68 presenting visual-functional mismatch, and 51 exhibiting reverse mismatch. The mismatch was associated with higher angiography-derived microcirculatory resistance (AMR) (adjusted odds ratio [aOR]=1.016, 95% CI: 1.010-1.022, P<0.001). Reverse mismatch was associated with larger area stenosis (aOR=1.044, 95% CI: 1.004-1.086, P=0.032), lower coronary flow velocity (aOR=0.690, 95% CI: 0.567-0.970, P<0.001) and lower AMR (aOR=0.947, 95% CI: 0.924-0.970, P<0.001). Additionally, the mismatch group showed the worst 18-month MACE-free survival among the four groups (Log rank test p = 0.013).

Conclusion

AMR plays a significant role in the occurrence of visual-functional mismatches between QCA-DS and QFR, and the mismatch group showed the worst prognosis.

Impact of thrombus aspiration on left ventricular remodeling and function in patients with ST-segment elevation myocardial infarction: A meta-analysis of randomized controlled trials

BACKGROUND

Routine thrombus aspiration (TA) does not improve clinical outcomes in patients with ST-segment-elevation myocardial infarction (STEMI), although data from meta-analyses suggest that patients with high thrombus burden may benefit from it. The impact of TA on left ventricular (LV) functional recovery and remodeling after STEMI remains controversial. We aimed to pool data from randomized controlled trials (RCTs) on the impact of TA on LV function and remodeling after primary percutaneous coronary intervention (pPCI).

METHODS

PubMed and CENTRAL databases were scanned for eligible studies. Primary outcome measures were: LV ejection fraction (LVEF), LV end diastolic volume (LVEDV), LV end systolic volume (LVESV) and wall motion score index (WMSI). A primary pre-specified subgroup analysis was performed comparing manual TA with mechanical TA.

RESULTS

A total of 28 studies enrolling 4990 patients were included. WMSI was lower in TA group than in control (mean difference [MD] -0.11, 95% confidence interval [CI] -0.19 to -0.03). A greater LVEF (MD 1.91, 95% CI 0.76 to 3) and a smaller LVESV (MD -6.19, 95% CI -8.7 to -3.6) were observed in manual TA group compared to control. Meta regressions including patients with left anterior descending artery (LAD) involvement showed an association between TA use and the reduction of both LVEDV and LVESV (z = -2.13, p = 0.03; z = -3.7, p < 0.01) and the improvement in myocardial salvage index (z = 2.04, p = 0.04).

CONCLUSION

TA is associated with improved LV function. TA technique, total ischemic time and LAD involvement appears to influence TA benefit on post-infarction LV remodeling.

Chinese expert consensus on the diagnosis and treatment of coronary microvascular diseases (2023 Edition)

Since the four working groups of the Chinese Society of Cardiology issued first expert consensus on coronary microvascular diseases (CMVD) in 2017, international consensus documents on CMVD have increased rapidly. Although some of these documents made preliminary recommendations for the diagnosis and treatment of CMVD, they did not provide classification of recommendations and levels of evidence. In order to summarize recent progress in the field of CMVD, standardize the methods and procedures of diagnosis and treatment, and identify the scientific questions for future research, the four working groups of the Chinese Society of Cardiology updated the 2017 version of the Chinese expert consensus on CMVD and adopted a series of measures to ensure the quality of this document. The current consensus has raised a new classification of CMVD, summarized new epidemiological findings for different types of CMVD, analyzed key pathological and molecular mechanisms, evaluated classical and novel diagnostic technologies, recommended diagnostic pathways and criteria, and therapeutic strategies and medications, for patients with CMVD. In view of the current progress and knowledge gaps of CMVD, future directions were proposed. It is hoped that this expert consensus will further expedite the research progress of CMVD in both basic and clinical scenarios.

Stroke and Recent Myocardial Infarction, Reduced Left Ventricular Ejection Fraction, Left Ventricular Thrombus, and Wall Motion Abnormalities

PURPOSE OF REVIEW

To review the evidence regarding stroke and recent myocardial infarction (MI), reduced left ventricular ejection fraction, left ventricular thrombus (LVT), and wall motion abnormalities (WMA).

RECENT FINDINGS

The risk of ischemic stroke associated with acute MI has been greatly reduced with reperfusion treatments that improved myocardium salvage. Acute ischemic stroke is an uncommon complication of diagnostic coronary angiography and percutaneous coronary intervention. For established LVT, anticoagulation is superior to antiplatelet medications to reduce the risk of ischemic stroke. The duration of anticoagulation should be at least 3 to 6 months. Direct oral anticoagulants have been used off-label in this context. In patients with low ejection fraction or WMA, there is no evidence that anticoagulation is superior to antiplatelet treatment in preventing ischemic stroke. In patients with ischemic stroke and recent MI (< 3 months), type of MI (STEMI or NSTEMI), timing, and location should be considered when deciding whether intravenous thrombolysis should be used for stroke treatment. Mechanical thrombectomy should be considered as a therapeutic alternative to intravenous thrombolysis in patients with acute ischemic stroke due to large-vessel occlusion and recent MI. Most guidelines regarding prevention of ischemic stroke in patients with these cardiac causes of stroke are derived from expert opinion. There is a need for high quality evidence to support stroke prevention treatments in these patients.

SARS-CoV-2 Positivity, Stent Thrombosis, and 30-day Mortality in STEMI Patients Undergoing Mechanical Reperfusion

SARS-Cov-2 has been suggested to promote thrombotic complications and higher mortality. The aim of the present study was to evaluate the impact of SARS-CoV-2 positivity on in-hospital outcome and 30-day mortality in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI) enrolled in the International Survey on Acute Coronary Syndromes ST-segment elevation Myocardial Infarction (ISACS-STEMI COVID-19 registry. The 109 SARS-CoV-2 positive patients were compared with 2005 SARS-CoV-2 negative patients. Positive patients were older (P = .002), less often active smokers (P = .002), and hypercholesterolemic (P = .006), they presented more often later than 12 h (P = .037), more often to the hub and were more often in cardiogenic shock (P = .02), or requiring rescue percutaneous coronary intervention after failed thrombolysis (P < .0001). Lower postprocedural Thrombolysis in Myocardial Infarction 3 flow (P = .029) and more thrombectomy (P = .046) were observed. SARS-CoV-2 was associated with a significantly higher in-hospital mortality (25.7 vs 7%, adjusted Odds Ratio (OR) [95% Confidence Interval] = 3.2 [1.71-5.99], P < .001) in-hospital definite in-stent thrombosis (6.4 vs 1.1%, adjusted Odds Ratio [95% CI] = 6.26 [2.41-16.25], P < .001) and 30-day mortality (34.4 vs 8.5%, adjusted Hazard Ratio [95% CI] = 2.16 [1.45-3.23], P < .001), confirming that SARS-CoV-2 positivity is associated with impaired reperfusion, with negative prognostic consequences.

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.

Canada acute coronary syndrome risk score predicts no-/slow-reflow in ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention

Background

The no-/slow-reflow phenomenon following primary percutaneous coronary intervention (PCI) in patients with ST-elevation myocardial infarction (STEMI)is associated with poor prognosis. The early identification of high-risk patients with no-/slow-reflow is critical. This study aimed to evaluate the predictive ability of the Canada Acute Coronary Syndrome (C-ACS) risk score for no-/slow-reflow in these patients.

Methods

Patients with STEMI who underwent primary PCI were consecutively enrolled and divided into three groups based on their C-ACS scores: 0, 1, and ≥2. The C-ACS score was computed using the four clinical variables evaluated at admission (one point for each): age ≥75 years, heart rate >100 beats/min, systolic blood pressure <100 mmHg, and Killip class >1. No-/slow-reflow was defined as thrombolysis in a myocardial infarction flow grade of 0-2 after primary PCI. The predictive ability of the C-ACS score for no-/slow-reflow was evaluated using a receiver operating characteristic curve.

Results

A total of 834 patients were enrolled, of whom 109 (13.1 %) developed no-/slow-reflow. The incidence of no-/slow-reflow increased from the C-ACS 0 group to the C-ACS ≥2 group (6.1 % vs 17.7 % vs 34.3 %, respectively, p < 0.001). After multivariable adjustment, the C-ACS score was an independent predictor of no-/slow-reflow (odd ratio 2.623, 95 % confidence interval 1.948-3.532, p < 0.001). Furthermore, the C-ACS score showed good discrimination for no-/slow-reflow (area under the curve 0.707, 95 % confidence interval 0.653-0.762, p < 0.001). Further subgroup analyses indicated a significant interaction between the C-ACS score and patient sex (p for interaction = 0.011). The independent association between the C-ACS score and no-/slow-reflow was only observed in male patients (odd ratio 3.061, 95 % confidence interval 1.931-4.852, p < 0.001). During a median follow-up duration of 4.3 years, the C-ACS score was independently associated with major adverse cardiovascular events independent of the occurrence of no-/slow-reflow (p for interaction = 0.212).

Conclusion

The C-ACS risk score could independently predict the no-/slow-reflow in patients with STEMI undergoing primary PCI, particularly in male patients.

Effect of optimized thrombus aspiration on myocardial perfusion and prognosis in acute ST-segment elevation myocardial infarction patients with primary percutaneous coronary intervention

Objective

To investigate the impact of optimized thrombus aspiration on myocardial perfusion, prognosis, and safety in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention(primary PCI).

Methods

A total of 129 patients with STEMI were randomly allocated into control group (Subgroup A and B) and experimental group(Subgroup C and D). Control group received percutaneous transluminal coronary angioplasty (PTCA),thrombus aspiration and primary PCI. Experimental group received optimized thrombus aspiration and primary PCI. The number of thrombus aspiration was less than 4 times in Subgroup A and C. The number of thrombus aspiration was performed more than 4 times in Subgroups B and D. The classification of thrombi extracted, the TIMI flow grade, the incidence of no-reflow and slow flow, cTFC, TPI and CK-MB at 12 h and 24 h after stenting, ST segment resolution of ECG after stenting, NT-proBNP, LVEFat 24 h, 30 days and 180 days after stenting were compared between groups. The incidence of intraoperative and postoperative bleeding complications, stroke events and major cardiovascular events (MACE) were recorded and compared between groups.

Results

The classification of thrombi extracted in the experimental group was higher than that in the control group. The TIMI flow grade of the experimental group was better than the control group after thrombus aspiration. After stenting, the advantage still existed, but the difference was not statistically significant. On cTFC, the experimental group was lower than the control group, but the difference was not statistically significant; After stenting the experimental group was significantly lower than the control group. The CK-MB at 12 h and 24 h of the experimental group was lower than the control group. After thrombus aspiration the incidence of no-reflow in the experimental group was significantly lower than that in the control group; after stenting the incidence of no-reflow in the experimental group was still lower than the control group, but no statistically difference. After thrombus aspiration and stenting the incidence of slow flow in the experimental group were lower than that in the control group. After stenting, NT-proBNP at 24 h was lower in the experimental group than that in the control group, However, there was no statistical difference; after stenting, The NT-proBNP in the experimental group was lower than that in the control group at 30 days and 180 days. After stenting, LVEF of the experimental group was significantly higher than the control group at 24 h and 30 days; superiority remained after 180 days but no statistical difference. There was no statistical difference between two groups for intraoperative and postoperative bleeding complications, stroke events, and MACE events. In Subgroup analysis,there was no significant difference in the classification of thrombi extracted, TIMI flow grade, cTFC, CK-MB,NT-proBNP and LVEF between group C and D, but group A was better than group B. Analysis of variance showed that the optimal number of suction was 4-5 times.

Conclusions

Optimized thrombus aspiration can significantly improve myocardial perfusion and short-term and medium-term prognosis of STEMI patients after PCI, and reduce the incidence of slow flow and no-reflow. The optimal suction times were 4-5 times. Traditional aspiration method with more aspiration times is harmful to cardiac prognosis. Thrombus aspiration does not increase the incidence of stroke events and is safe.Clinical Trial Registration: identifier, ChiCTR2300073410.

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).

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.

Optical coherence tomography-guided versus angiography-guided percutaneous coronary intervention in acute coronary syndrome: a meta-analysis

BACKGROUND

Percutaneous coronary intervention (PCI) is standard of care in patients with acute coronary syndrome (ACS) suitable for interventional revascularization. Intracoronary imaging by optical coherence tomography (OCT) expanded treatment approaches adding diagnostic information and contributing to stent optimization.

OBJECTIVES

This meta-analysis aimed to assess the effects of OCT-guided vs. angiography-guided PCI in treatment of ACS.

METHODS

A structured literature search was performed. All controlled trials evaluating OCT-guided vs. angiography-guided PCI in patients with ACS were eligible. The primary end point was major adverse cardiac events (MACE).

RESULTS

Eight studies enrolling 2612 patients with ACS were eligible. 1263 patients underwent OCT-guided and 1,349 patients angiography-guided PCI. OCT guidance was associated with a 30% lower likelihood of MACE (OR 0.70, 95% CI 0.53-0.93, p = 0.01, I² = 1%). OCT-guided PCI was also associated with significantly decreased cardiac mortality (OR 0.49, 95% CI 0.25-0.96, p = 0.04, I² = 0%). There was no detectable difference in all-cause mortality (OR 1.08, 95% CI 0.51-2.31, p = 0.83, I² = 0). Patients in OCT-guided group less frequently required target lesion revascularization (OR 0.26, 95% CI 0.07-0.95, p = 0.04, I² = 0%). Analysis of myocardial infarction did not result in significant treatment differences. In subgroup or sensitivity analysis the observed advantages of OCT-guided PCI were not replicable.

CONCLUSION

The evidence suggests that PCI guidance with OCT in ACS decreases MACE, cardiac death and target lesion revascularization compared to angiography. On individual study level, in subgroup or sensitivity analyses these advantages were not thoroughly replicable.

Large Vessel Occlusion Stroke due to Intracranial Atherosclerotic Disease: Identification, Medical and Interventional Treatment, and Outcomes

Large vessel occlusion stroke due to underlying intracranial atherosclerotic disease (ICAD-LVO) is prevalent in 10 to 30% of LVOs depending on patient factors such as vascular risk factors, race and ethnicity, and age. Patients with ICAD-LVO derive similar functional outcome benefit from endovascular thrombectomy as other mechanisms of LVO, but up to half of ICAD-LVO patients reocclude after revascularization. Therefore, early identification and treatment planning for ICAD-LVO are important given the unique considerations before, during, and after endovascular thrombectomy. In this review of ICAD-LVO, we propose a multistep approach to ICAD-LVO identification, pretreatment and endovascular thrombectomy considerations, adjunctive medications, and medical management. There have been no large-scale randomized controlled trials dedicated to studying ICAD-LVO, therefore this review focuses on observational studies.

RGD peptide modified RBC membrane functionalized biomimetic nanoparticles for thrombolytic therapy

In recent years, the fabrication of nano-drug delivery systems for targeted treatment of thrombus has become a research hotspot. In this study, we intend to construct a biomimetic nanomedicine for targeted thrombus treatment. The poly lactic-co-glycolic acid (PLGA) was selected as the nanocarrier material. Then, urokinase and perfluoro-n-pentane (PFP) were co-loaded into PLGA by the double emulsification solvent evaporation method to prepare phase change nanoparticles PPUNPs. Subsequently, the RGD peptide-modified red blood cell membrane (RBCM) was coated on the surface of PPUNPs to prepare a biomimetic nano-drug carrier (RGD-RBCM@PPUNPs). The as-prepared RGD-RBCM@PPUNPs possessed a "core-shell" structure, have good dispersibility, and inherited the membrane protein composition of RBCs. Under ultrasound stimulation, the loaded urokinase could be rapidly released. In vitro cell experiments showed that RGD-RBCM@PPUNPs had good hemocompatibility and cytocompatibility. Due to the coated RGD-RBC membrane, RGD-RBCM@PPUNPs could effectively inhibit the uptake of macrophages. In addition, RGD-RBCM@PPUNPs showed better thrombolytic function in vitro. Overall, the results suggested that this biomimetic nanomedicine provided a promising therapeutic strategy for the targeted therapy of thrombosis.

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.

Excimer laser coronary angioplasty versus manual aspiration thrombectomy in patients with ST-segment elevation myocardial infarction: analyzed by nuclear scintigraphy

Clinical outcomes concerning the efficacy of excimer laser coronary angioplasty (ELCA) in real-world cases of acute myocardial infarction (MI) are limited. We evaluated and compared the impact of ELCA with manual aspiration thrombectomy on myocardial salvage and left ventricular (LV) systolic/diastolic function in patients with ST-segment elevation MI (STEMI) using nuclear scintigraphy.  We enrolled 143 consecutive patients with STEMI treated with ELCA (63 patients) or manual aspiration thrombectomy (80 patients) between September 2016 and December 2020 in a single-center hospital. We evaluated the peak creatine kinase (CK)/ creatine kinase-myocardial band (CK-MB) levels and performed single-photon emission computed tomography (SPECT) analyses with Quantitative Gated SPECT and Quantitative Perfusion SPECT (Auto QUANT 7.2) at 3-10 days using ¹²³I-BMIPP and 3 months following percutaneous coronary intervention using ^99mTc-tetrofosmin to evaluate myocardial salvage and LV systolic/diastolic function. No significant difference was observed in the patient and periprocedural characteristics. Peak CK-MB level was significantly different between the groups (ELCA group, 190.0 [70.5-342.0] IU/L vs. aspiration group, 256.5 [157.0-354.8] IU/L, p = 0.047). Although no significant difference was observed in myocardial salvage, significant improvement in the LV ejection fraction (14.1 [6.2-19.8]% vs. 9.5 [3.9-15.3]%, respectively, p = 0.018) and peak emptying rate (-0.54 [-1.02- (-0.27)] mL/s vs. -0.38 [-0.76- (-0.05)] mL/s, respectively, p = 0.017) were detected. ELCA could suppress the myocardial deviation enzymes and potentially improve systolic function compared to manual aspiration thrombectomy in patients with STEMI.

Effects of intracoronary low-dose prourokinase administration on ST-segment elevation in patients with myocardial infarction and a high thrombus burden: a randomized controlled trial

OBJECTIVE

To evaluate the efficacy and safety of low-dose prourokinase (pro-UK) administration during primary percutaneous coronary intervention (PCI) for the treatment of acute ST-segment elevation myocardial infarction (STEMI) in patients with a high thrombus burden.

METHODS

A prospective, randomized controlled trial was conducted at the Inner Mongolia People's Hospital, China. Patients with STEMI and a high thrombus burden who underwent thrombus aspiration and primary PCI were randomly allocated to pro-UK administration or control groups. The primary endpoint was corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC).

RESULTS

There were no significant differences in the baseline demographics or clinical characteristics of the two groups. The CTFC, tissue myocardial perfusion grade, ST-segment resolution, and myocardial blush grade of the pro-UK group were significantly better than those of the control group. In addition, after 30 days of follow-up, the pro-UK group had better cardiac function and perfusion than the control group. There were no differences in the clinical outcomes or incidence of hemorrhage.

CONCLUSIONS

Intracoronary low-dose pro-UK improves myocardial perfusion and cardiac function in patients with a high thrombus burden. Major hemorrhages still occur in patients administered pro-UK, but are no more frequent.Study registration: Chinese Clinical Trial Registry (ChiCTR1900022290).

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.

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

OBJECTIVES

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Machine learning assisted reflectance spectral characterisation of coronary thrombi correlates with microvascular injury in patients with ST-segment elevation acute coronary syndrome

Aims

We set out to further develop reflectance spectroscopy for the characterisation and quantification of coronary thrombi. Additionally, we explore the potential of our approach for use as a risk stratification tool by exploring the relation of reflectance spectra to indices of coronary microvascular injury.

Methods and results

We performed hyperspectral imaging of coronary thrombi aspirated from 306 patients presenting with ST-segment elevation acute coronary syndrome (STEACS). Spatially resolved reflected light spectra were analysed using unsupervised machine learning approaches. Invasive [index of coronary microvascular resistance (IMR)] and non-invasive [microvascular obstruction (MVO) at cardiac magnetic resonance imaging] indices of coronary microvascular injury were measured in a sub-cohort of 36 patients. The derived spectral signatures of coronary thrombi were correlated with both invasive and non-invasive indices of coronary microvascular injury. Successful machine-learning-based classification of the various thrombus image components, including differentiation between blood and thrombus, was achieved when classifying the pixel spectra into 11 groups. Fitting of the spectra to basis spectra recorded for separated blood components confirmed excellent correlation with visually inspected thrombi. In the 36 patients who underwent successful thrombectomy, spectral signatures were found to correlate well with the index of microcirculatory resistance and microvascular obstruction; R²: 0.80, p < 0.0001, n = 21 and R²: 0.64, p = 0.02, n = 17, respectively.

Conclusion

Machine learning assisted reflectance spectral analysis can provide a measure of thrombus composition and evaluate coronary microvascular injury in patients with STEACS. Future work will further validate its deployment as a point-of-care diagnostic and risk stratification tool for STEACS care.

MINOCA: One Size Fits All? Probably Not—A Review of Etiology, Investigation, and Treatment

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a heterogeneous group of conditions that include both atherosclerotic (coronary plaque disruption) and non-atherosclerotic (spontaneous coronary artery dissection, coronary artery spasm, coronary artery embolism, coronary microvascular dysfunction, and supply–demand mismatch) causes resulting in myocardial damage that is not due to obstructive coronary artery disease. Failure to identify the underlying cause may result in inadequate and inappropriate therapy in these patients. The cornerstone of managing MINOCA patients is to identify the underlying mechanism to achieve the target treatment. Intravascular imaging is able to identify different morphologic features of coronary plaques, while cardiac magnetic resonance is the gold standard for detection of myocardial infarction in the setting of MINOCA. In this review, we summarize the relevant clinical issues, contemporary diagnosis, and treatment options of MINOCA.

Neurointerventional tools and techniques for coronary thrombus removal. A case-based review

Due to the negative results of randomized aspiration thrombectomy studies, its role in myocardial infarction has been limited to high thrombus burden and/or failed vessel recanalization, with little technological advancement over the last years. In contrast, there has been rapid progress in mechanical thrombectomy in stroke, which is understandable as most ischemic cerebrovascular accidents have an embolic etiology.We present three transradial procedures wherein neurointerventional catheters were used as a first-line device for en bloc removal of large clots lodged distally in tortuous coronary anatomy. First-pass reperfusion was achieved in all the cases, without dissection, distal embolization, or the no reflow phenomenon.

Learning objective

In the case of large clots, where coronary aspiration devices fail, neurointerventional catheters may be considered as a rescue strategy. They provide large aspiration lumen and excellent trackability with atraumatic design. Many other neurointerventional techniques can be easily adopted into the coronary armamentarium, possibly increasing the safety and efficacy of thrombus aspiration.

Early survival after acute myocardial infarction with ST-segment elevation: What could be improved? Insights from France PCI French registry

Early mortality post-ST-segment elevation myocardial infarction (STEMI) in France remains high. The multicentre France Percutaneous Coronary Intervention Registry includes every patient undergoing coronary angiography in France. We analyzed the prevalence and impact of unmodifiable and modifiable risk factors on 30-day survival in patients experiencing STEMI. Patients admitted for STEMI between 01/2014 and 12/2016 were included in the analysis. Patients with nonobstructive coronary artery disease, with cardiogenic shock or cardiac arrest without STEMI, were excluded. Prehospital, clinical and procedural data were collected prospectively by the cardiologist in the cath lab using medical reporting software. Information on outcomes, including mortality, was obtained by a dedicated research technician by phone calls or from medical records. Marginal Cox proportional hazards regression was used to test the predictive value for survival at 30 days in a multivariable analysis. Included were 2590 patients (74% men) aged 63 ± 14 years. During the first month, 174 patients (6.7%) died. After adjustment, unmodifiable variables significantly associated with reduced 30-day survival were: age > 80 years (prevalence 15%; hazard ratio [HR] 2.7; 95% confidence interval [CI] 1.5-4.7), chronic kidney disease (2%; HR 5.3; 95% CI 2.6-11.1), diabetes mellitus (14%; HR 1.6; 95% CI 1.0-2.5), anterior or circumferential electrical localization (39%; HR 2.0; 95% CI 1.4-2.9), and Killip class 2, 3, or 4 (7%; HR 3.4; 95% CI 1.9-5.9; 2%; HR 10.1; 95% CI 5.3-19.4; 4%; HR 18; 95% CI 10.8-29.8, respectively). Among modifiable variables, total ischemic time > 3 hours (68%; HR 1.8; 95% CI 1.1-3.0), lack of appropriate premedication (18%; HR 2.2; 95% CI 1.5-3.3), and post-PCI TIMI < 3 (6%; HR 4.9; 95% CI 3.2-7.6) were significantly associated with reduced 30-day survival. Most predictors of 30-day survival post-STEMI are unmodifiable, but outcomes might be improved by optimizing modifiable factors, most importantly ischemic time and appropriate premedication.

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.

Cardiac Magnetic Resonance Shows Improved Outcomes in Patients with an ST-Segment Elevation Myocardial Infarction and a High Thrombus Burden Treated with Adjuvant Aspiration Thrombectomy

There is a discrepancy between epicardial vessel patency and microcirculation perfusion in a third of patients treated with percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). Optimization with aspiration thrombectomy (AT) may reduce distal embolization and microvascular obstruction. The effect of AT in the treatment of STEMI is debatable. The purpose of this study was to use cardiac magnetic resonance (CMR) to determine whether AT influences microvascular obstruction (MVO), infarct size and left ventricular (LV) remodelling in STEMI patients. Sixty STEMI patients with a thrombus-occluded coronary artery were randomized in a 2:1 fashion to receive PCI proceeded by AT (AT + PCI group), or PCI only. MVO, myocardial infarct size and LV remodelling were assessed by CMR during the index hospitalization and 6 months thereafter. The majority of patients had a large thrombus burden (TIMI thrombus grade 5 in over 70% of patients). PCI and AT were effective in all cases. There were no periprocedural strokes. CMR showed that the addition of AT to standard PCI was associated with lesser MVO when indexed to the infarct size and larger infarct size reduction. There were less patients with left ventricle remodelling in the AT + PCI vs. the PCI only group. To conclude, in STEMI patients with a high thrombus burden, AT added to PCI is effective in reducing infarct size, MVO and LV remodelling.

Combined therapy with dapagliflozin and entresto offers an additional benefit on improving the heart function in rat after ischemia-reperfusion injury

BACKGROUND

This study tested whether combined dapagliflozin and entresto treatment would be superior to either one alone for preserving the left-ventricular ejection-fraction (LVEF) in rat after ischemia-reperfusion (IR) injury.

METHODS AND RESULTS

In vitro flow-cytometric result showed that the intracellular and mitochondrial reactive oxygen species and mitochondrial permeability transition pore, and protein levels of oxidative-stress/DNA-damaged markers [NADPH-oxidase-1 (NOX-1)/NOX-2/oxidized-protein/γ-H2A-histone-family member X (γ-H2AX)] were significantly higher in hydrogen peroxide (H₂O₂) (300μM)-treated H9C2 cells as compared with the controls that were significantly reversed in sacubitril/valsartan and dapagliflozin therapy in the same H₂O₂-treated condition, whereas the protein expressions of antioxidants [Sirtuin-1 (SIRT1)/SIRT3/superoxide dismutase/catalase/glutathione peroxidase) exhibited an opposite pattern among the groups (all p<0.001). Adult-male-Sprague-Dawley rat (n=40) were equally categorized into group 1 (sham-operated control), group 2 (IR), group 3 (IR+dapagliflozin/20mg/kg/orally at 3h and post-days 1/2/3 after IR), group 4 (IR+entresto/100mg/kg/orally at 3h and post-days 1/2/3 after IR) and group 5 (IR+dapagliflozin+entresto) and the hearts were harvested by day 3 after IR. The 3^rd day's LVEF was highest in group 1, lowest in group 2 and significantly higher in group 5 than in groups 3/4, but it was similar between the latter two groups (p<0.001). The protein expressions of oxidative-stress (NOX-1/NOX-2/oxidized protein), fibrotic (transforming-growth factor-ß/phosphorylated-Smad3), apoptotic [mitochondrial-Bax/cleaved-caspase-3/cleaved-poly (ADP-ribose) polymerase], mitochondria/DNA damaged (cytosolic-cytochrome-C/γ-H2AX), pressure-overload/heart-failure [brain natriuretic peptide (BNP)/ß-myosin heavy chain] and autophagic (ratio of meiotic cyclins CLB3-II/CLB3-I) biomarkers, and the upstream (high-mobility group box 1/Toll-like receptor-4/MyD88/phosphorylated-nuclear factor-κB and downstream [interleukin (IL)-1ß/IL-6/tumor necrosis factor-α] inflammatory signalings revealed an antithetical features of LVEF among the groups (all p<0.0001). The cellular levels of inflammatory (myeloperoxidase+/CD68+), pressure-overload/heart-failure (BNP+) and DNA-damage (γ-H2AX+) biomarkers as well as infarct area demonstrated an opposite pattern of LVEF among the groups (all p<0.0001).

CONCLUSION

Incorporated entresto-dapagliflozin treatment was superior to either one alone on protecting the heart against IR injury.

Gradual Versus Abrupt Reperfusion During Primary Percutaneous Coronary Interventions in ST‐Segment–Elevation Myocardial Infarction (GUARD)

Background

Intramyocardial edema and hemorrhage are key pathological mechanisms in the development of reperfusion‐related microvascular damage in ST‐segment–elevation myocardial infarction. These processes may be facilitated by abrupt restoration of intracoronary pressure and flow triggered by primary percutaneous coronary intervention. We investigated whether pressure‐controlled reperfusion via gradual reopening of the infarct‐related artery may limit microvascular injury in patients undergoing primary percutaneous coronary intervention.

Methods and Results

A total of 83 patients with ST‐segment–elevation myocardial infarction were assessed for eligibility and 53 who did not meet inclusion criteria were excluded. The remaining 30 patients with totally occluded infarct‐related artery were randomized to the pressure‐controlled reperfusion with delayed stenting (PCRDS) group (n=15) or standard primary percutaneous coronary intervention with immediate stenting (IS) group (n=15) (intention‐to‐treat population). Data from 5 patients in each arm were unsuitable to be included in the final analysis. Finally, 20 patients undergoing primary percutaneous coronary intervention who were randomly assigned to either IS (n=10) or PCRDS (n=10) were included. In the PCRDS arm, a 1.5‐mm balloon was used to achieve initial reperfusion with thrombolysis in myocardial infarction grade 3 flow and, subsequently, to control distal intracoronary pressure over a 30‐minute monitoring period (MP) until stenting was performed. In both study groups, continuous assessment of coronary hemodynamics with intracoronary pressure and Doppler flow velocity was performed, with a final measurement of zero flow pressure (primary end point of the study) at the end of a 60‐minute MP. There were no complications associated with IS or PCRDS. PCRDS effectively led to lower distal intracoronary pressures than IS over 30 minutes after reperfusion (71.2±9.37 mm Hg versus 90.13±12.09 mm Hg, P =0.001). Significant differences were noted between study arms in the microcirculatory response over MP. Microvascular perfusion progressively deteriorated in the IS group and at the end of MP, and hyperemic microvascular resistance was significantly higher in the IS arm as compared with the PCDRS arm (2.83±0.56 mm Hg.s.cm −1 versus 1.83±0.53 mm Hg.s.cm −1 , P =0.001). The primary end point (zero flow pressure) was significantly lower in the PCRDS group than in the IS group (41.46±17.85 mm Hg versus 76.87±21.34 mm Hg, P =0.001). In the whole study group (n=20), reperfusion pressures measured at predefined stages in the early reperfusion period showed robust associations with zero flow pressure values measured at the end of the 1‐hour MP (immediately after reperfusion: r =0.782, P <0.001; at the 10th minute: r =0.796, P <0.001; and at the 20th minute: r =0.702, P =0.001) and peak creatine kinase MB level (immediately after reperfusion: r =0.653, P =0.002; at the 10th minute: r =0.597, P =0.007; and at the 20th minute: r =0.538, P =0.017). Enzymatic myocardial infarction size was lower in the PCRDS group than in the IS group with peak troponin T (5395±2991 ng/mL versus 8874±1927 ng/mL, P =0.006) and creatine kinase MB (163.6±93.4 IU/L versus 542.2±227.4 IU/L, P <0.001).

Conclusions

In patients with ST‐segment–elevation myocardial infarction, pressure‐controlled reperfusion of the culprit vessel by means of gradual reopening of the occluded infarct‐related artery (PCRDS) led to better‐preserved coronary microvascular integrity and smaller myocardial infarction size, without an increase in procedural complications, compared with IS.

Registration

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02732080.