Coronary thrombus in patients undergoing primary PCI for STEMI: Prognostic significance and management

Outcomes of patients with acute ST-segment elevation myocardial infarction treated by a prolonged “Deferred” percutaneous coronary intervention strategy

BACKGROUND

Primary percutaneous coronary intervention (PCI) is the preferred treatment for ST-segment elevation myocardial infarction (STEMI). However, in patients with high thrombus burden, immediate stenting during PCI can lead to poor outcomes due to the risk of thrombus migration and subsequent microvascular occlusion, resulting in no-reflow phenomena. Deferred stenting offers a potential advantage by allowing for the reduction of thrombus load, which may help to minimize the incidence of slow-flow and no-reflow complications. This study explores the effectiveness of a deferred stenting strategy in improving outcomes for STEMI patients.

AIM

To evaluate the effectiveness and safety of deferred PCI in a real-world setting in acute STEMI patients.

METHODS

This study was conducted at King George’s Medical University, Lucknow, from October 1, 2018, to October 30, 2019 and included a total of 55 participants. Patients with acute STEMI who underwent coronary angiography were selected for a deferred PCI strategy based on specific angiographic features.

RESULTS

Anterior wall myocardial infarction was the predominant type of STEMI in 62% of the selected 55 patients (mean age: 54 years; 70% males), and diabetes mellitus was the most common risk factor (18.2%), followed by hypertension (16.2%). On the second angiogram of these patients measures of thrombus grade, thrombolysis in myocardial infarction flow grade, myocardial blush grade, and severity of stenosis of culprit lesion were considerably improved compared to the first angiogram, and the average culprit artery diameter had increased by 7.8%. Most patients (60%) had an uneventful hospital stay during the second angiogram and an uneventful intraprocedural course (85.19%), with slow-flow/no-reflow occurring only in 7.4% of the patients; these patients recovered after taking vasodilator drugs. In 29.3% of patients, the culprit artery was recanalized, preventing unnecessary stent deployment.

CONCLUSION

Deferred PCI strategy is safe and reduces the thrombus burden, improves thrombolysis in myocardial infarction (TIMI) flow, improves myocardial blush grade, and prevents unwarranted stent deployment.

Clinical Outcomes With Postprocedural Anticoagulation Versus No Anticoagulation in Patients With Acute Myocardial Infarction After Percutaneous Coronary Intervention: A Meta-Analysis

Postprocedural anticoagulation (PPAC) after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) can mitigate thrombotic events. However, current clinical guidelines do not recommend PPAC after PCI considering the scarce evidence supporting its use. A comprehensive literature search of electronic databases was conducted to identify studies comparing PPAC to no anticoagulation (AC) after PCI for AMI. Using the inverse-variance random-effects model, we pooled risk ratios (RRs) with 95% confidence intervals (CIs), with P < 0.05 considered statistically significant. Seven studies with a total of 47,981 patients (32,010: PPAC and 15,971: no AC) were included in the final analysis. PPAC administration demonstrated no significant difference in 30-day all-cause mortality [RR, 0.73 (95% CI, 0.47-1.16); P = 0.19], 30-day cardiovascular mortality [RR, 0.76 (95% CI, 0.45-1.30); P = 0.32], 30-day myocardial infarction [RR, 0.68 (95% CI, 0.41-1.12); P = 0.13], 30-day stroke [RR, 0.89 (95% CI, 0.47-1.67); P = 0.71], 30-day target vessel revascularization [RR, 0.74 (95% CI, 0.37-1.47); P = 0.39], 30-day stent thrombosis [RR, 1.08 (95% CI, 0.75-1.57); P = 0.67], and 30-day bleeding [RR, 1.25 (95% CI, 0.83-1.88); P = 0.29] compared with no AC. This meta-analysis concludes that there are no benefits of routine PPAC after PCI in AMI. The decision to prolong anticoagulant use post-PCI depends on risk versus benefits, which vary from case to case. Future large-scale multicentric randomized trials are warranted to corroborate the results of this meta-analysis.

Bridging With Low-Molecular-Weight Heparin Versus Antiplatelet Therapy in Patients Undergoing Noncardiac Surgery After Percutaneous Coronary Intervention: A Comprehensive Review

BACKGROUND

This review article discussed the use of bridging therapy with low-molecular-weight heparin (LMWH) in patients who undergo noncardiac surgery (NCS) after percutaneous coronary intervention (PCI).

HYPOTHESES

Patients who undergo PCI are at an increased risk of thrombotic events due to their underlying cardiovascular disease. However, many of these patients may require NCS at some point in their lives, which poses a significant challenge for clinicians as they balance the risk of thrombotic events against the risk of bleeding associated with antithrombotic therapy.

RESULTS

This review evaluates the current evidence on the use of bridging therapy with LMWH in patients undergoing NCS after PCI, focusing on outcomes related to the efficacy and safety of antithrombotic therapy. The article also discusses the limitations of the current evidence and highlights areas where further research is needed to optimize the management of antithrombotic therapy in this patient population.

CONCLUSION

The goal of this review was to provide clinicians with a comprehensive summary of the available evidence to guide clinical decision-making and improve patient outcomes.

The Relationship of Coronary Thrombus Burden and Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA) Score in Patients With ST-Segment Elevation Myocardial Infarction

BACKGROUND

The anticoagulation and risk factors in atrial fibrillation (ATRIA) score is associated with adverse cardiovascular events. However, its relationship with coronary thrombus burden is unclear. Therefore, we aimed to investigate the relationship between the ATRIA score and thrombus burden in patients with ST-segment elevation myocardial infarction (STEMI) who underwent percutaneous coronary intervention (PCI).

MATERIALS AND METHODS

The study was designed as a prospective cross-sectional observational study. Our study included 319 patients who were prospectively admitted with STEMI between January 2021 and April 2022. Patients were divided into 2 groups with low thrombus burden (LTB) (grade <3) and high thrombus burden (HTB) (grade ≥3). ATRIA score was calculated and recorded for all patients. ATRIA scores of both groups were compared.

RESULTS

In our study, 58.9% (n  =  188) of patients in the LTB group and 41% (n  =  131) of patients in the HTB group. The ATRIA risk score (p < .001) was significantly higher in the HTB group. In multivariate logistic regression analysis, ATRIA score, glomerular filtration rate, hypertensıon, abciximab usage, and no-reflow were found to be independent predictors of HTB in STEMI patients undergoing primary PCI. In receiver operating characteristic analysis, ATRIA score >4 had a sensitivity of 66.2% and specificity of 95.2%, and ATRIA score >8 sensitivity of 98% and specificity of 100% predicted HTB.

CONCLUSION

In this study, we found that thrombus burden may be associated with ATRIA risk score in patients presenting with STEMI.

Exosomes as cutting-edge therapeutics in various biomedical applications: An update on engineering, delivery, and preclinical studies

Exosomes are cell-derived nanovesicles, circulating in different body fluids, and acting as an intercellular mechanism. They can be purified from culture media of different cell types and carry an enriched content of various protein and nucleic acid molecules originating from their parental cells. It was indicated that the exosomal cargo can mediate immune responses via many signaling pathways. Over recent years, the therapeutic effects of various exosome types were broadly investigated in many preclinical studies. Herein, we present an update on recent preclinical studies on exosomes as therapeutic and/or delivery agents for various applications. The exosome origin, structural modifications, natural or loaded active ingredients, size, and research outcomes were summarized for various diseases. Overall, the present article provides an overview of the latest exosome research interests and developments to clear the way for the clinical study design and application.

Manual Thrombus Aspiration in Patients With ST-Elevation Myocardial Infarction With High Thrombus Burden and a Total Ischemic Time Greater or Equal Than 3 Hours: Mini Review

Manual Thrombus Aspiration (MTA) reduces thrombus burden and improves myocardial reperfusion markers in patients with ST-segment elevation myocardial infarction (STEMI), however its clinical benefit is controversial due to conflicting results from randomized clinical trials, which is why the benefit of its application during primary angioplasty (PA) remains uncertain. Reports such as that of Doo Sun Sim, et al. suggest that the impact of MTA may become clinically relevant in patients with a longer total ischemia time.1 We present the case of an adult male, with multiple risk factors for coronary disease, with lower STEMI, due to occlusion of the right coronary artery with a heavy thrombus load and an ischemia time of 10 hours. It was successfully treated by MTA, removing abundant intracoronary thrombus and obtaining a TIMI III flow, without requiring stent implantation. The case, the evolution and the current knowledge regarding the use of AT are discussed. Our case report and review of five cases with similar characteristics in the literature illustrate the use of MTA in patients with STEMI, high thrombus burden, and prolonged ischemia time.

The Relationship Between TIMI Flow and MAPH Score in Patients Undergoing Primary Percutaneous Coronary Intervention for STEMI

The MAPH (mean platelet volume, age, total protein and hematocrit) score is a newly developed simple scoring system for patients with STEMI that has been associated with satisfactory predictive values to determine thrombus burden in STEMI patients. Therefore, the aim of our study was to determine the relationship between the MAPH risk score and TIMI flow in patients with STEMI.The study included 260 patients who underwent primary percutaneous coronary intervention between December 2019 to July 2022, and had TIMI 0 flow in the responsible coronary artery due to STEMI. According to the TIMI flow score after stent implantation, the patients were classified into either the no-reflow group (n = 59) or the normal flow group (n = 201). In order to calculate the MAPH score, ROC analysis was performed to find the cutoff point for each component of the MAPH score. MAPH scores were calculated (MPV + Age + Protein + Hematocrit) for both groups. Our study was a retrospective, observational study.In the multivariable regression analysis, the MAPH score (OR: 0.567; 95%CI: 0.330-0.973, P = 0.04) and glycoprotein IIb/IIIa inhibitors (OR: 0.249; 95%CI: 0.129-0.483, P < 0.001) were parameters found to be independent predictors of TIMI flow. An MAPH score value > 2.5 predicted the presence of low TIMI coronary flow in patients with STEMI, with 78% specificity and 45% sensitivity (ROC area under curve: 0.691, 95% CI: 0.617-0.766, P < 0.001).The MAPH risk score is simple, inexpensive, and quick to calculate. A high MAPH score may be an indicator of coronary no-reflow in patients with STEMI.

Predilation Ballooning in High Thrombus Laden STEMIs: An Independent Predictor of Slow Flow/No-Reflow in Patients Undergoing Emergent Percutaneous Coronary Revascularization

Background

Distal embolization due to microthrombus fragments formed during predilation ballooning is considered one of the possible mechanisms of slow flow/no-reflow (SF/NR). Therefore, this study aimed to compare the incidence of intraprocedure SF/NR during the primary percutaneous coronary intervention (PCI) in patients with high thrombus burden (≥4 grade) with and without predilation ballooning for culprit lesion preparation. Methodology. This prospective descriptive cross-sectional study included patients with a high thrombus burden (≥4 grades) who underwent primary PCI. Propensity-matched cohorts of patients with and without predilation ballooning in a 1 : 1 ratio were compared for the incidence of intraprocedure SF/NR.

Results

A total of 765 patients with high thrombus burden undergoing primary PCI were included in this study. The mean age was 55.75 ± 11.54 years, and 78.6% (601) were males. Predilation ballooning was conducted in 346 (45.2%) patients. The incidence of intraprocedure SF/NR was significantly higher (41.3% vs. 27.4%; p < 0.001) in patients with predilation ballooning than in those without preballooning, respectively. The incidence of intraprocedure SF/NR also remained significantly higher for the predilation ballooning cohort with an incidence rate of 41.3% as against 30.1% (p=0.002) for the propensity-matched cohort of patients without predilation ballooning with a relative risk of 1.64 (95% CI: 1.20 to 2.24). Moreover, the in-hospital mortality rate remained higher but insignificant, among patients with and without predilation ballooning (8.1% vs. 4.9%; p=0.090).

Conclusion

In conclusion, predilation ballooning can be associated with an increased risk of incidence of intraprocedure SF/NR during primary PCI in patients with high thrombus burden.

A New Score for Determining Thrombus Burden in STEMI Patients: The MAPH Score

Aim

to investigate whether the MAPH score, which is a new score that combines blood viscosity biomarkers such as mean platelet volume (MPV), total protein and hematocrit, can be used to predict thrombus burden in ST-segment elevation myocardial infarction (STEMI) patients.

Methods

A total of 473 consecutive patients with STEMI were included in the study. Intracoronary tirofiban/abciximab infusion was applied to patients with thrombus load ≥3 and these patients (n = 71) were defined as the patient group with high thrombus load. MPV, age, hematocrit and total protein values of the patients were recorded. High shear rate (HSR) and low shear rate (LSR) were calculated from total protein and hematocrit values. Cut-off values were determined for high thrombus load by using Youden index, and score was determined as 0 or 1 according to cut-offs. The sum of the scores was calculated as the MAPH score.

Results

The mean age of the patients included in the study was 59.6 ± 12.6 (n = 354 male, 74.8%). There was no difference between the groups in terms of gender, HT and DM (P = .127, P = .402 and P = .576, respectively). In the group with high thrombus load; total protein, MPV and hematocrit values were higher (P < .001, P = .001 and P = .03, respectively). Comparison of receiver operating characteristic (ROC) curve analysis revealed that the MAPH score had better performance in predicting higher thrombus load than both other self-containing parameters and HSR and LSR.

Conclusion

The MAPH score may be a new score that can be used to determine thrombus burden in STEMI patients.

Effectiveness of LODS, OASIS, and SAPS II to predict in-hospital mortality for intensive care patients with ST elevation myocardial infarction

The relationship between three scoring systems (LODS, OASIS, and SAPS II) and in-hospital mortality of intensive care patients with ST segment elevation myocardial infarction (STEMI) is currently inconclusive. The baseline data, LODS score, OASIS score, SAPS II score, and in-hospital prognosis of intensive care patients with STEMI were retrieved from the Medical Information Mart for Intensive Care IV database. Propensity score matching analysis was performed to reduce bias. Receiver operating characteristic curves (ROC) were drawn for the three scoring systems, and comparisons between the areas under the ROC curves (AUC) were conducted. Decision curve analysis (DCA) was performed to determine the net benefits of the three scoring systems. LODS and SAPS II were independent risk factors for in-hospital mortality. For the study cohort, the AUCs of LODS, OASIS, SAPS II were 0.867, 0.827, and 0.894; after PSM, the AUCs of LODS, OASIS, SAPS II were 0.877, 0.821, and 0.881. A stratified analysis of the patients who underwent percutaneous coronary intervention/coronary artery bypass grafting (PCI/CABG) or not was conducted. In the PCI/CABG group, the AUCs of LODS, OASIS, SAPS II were 0.853, 0.825, and 0.867, while in the non-PCI/CABG group, the AUCs of LODS, OASIS, SAPS II were 0.857, 0.804, and 0.897. The results of the Z test suggest that the predictive value of LODS and SAPS II was not statistically different, but both were higher than OASIS. According to the DCA, the net clinical benefit of LODS was the greatest. LODS and SAPS II have excellent predictive value, and in most cases, both were higher than OASIS. With a more concise composition and greater clinical benefit, LODS may be a better predictor of in-hospital mortality for intensive care patients with STEMI.

[Our enemy : the clot. Coronary thrombosis : strategy and therapeutic arsenal]

Intra coronary thrombus is  frequently encountered during acute coronary syndromes revascularisation procedures. It can also be encountered during angioplasty procedures in a stable angina context, although at a much lesser frequency.In both situations, it harbors a risk of poor angiographic result and poor prognosis. Intracoronnary thrombus may cause coronary occlusion at the angioplasty site or distal embolic  flow obstruction. Per procedure thrombus prevention rests on an prior optimal anti thrombotic treatment and in some circumstances the choice to defer the revascularisation procedure in the complex high risk setting. Treating the initiated thrombus remains controversial concerning thrombectomy and GPIIBIIIa inhibitors which are still in use in common practice. No reflow phenomenon is a particularly complex setting during cornary angioplasties, partially but not solely related to a thrombotic complication. It's treatment remains unclear in the absence of related oriented studies.The current mechanical and pharmacological antithrombotic therapies must remain common practice and used appropriately as of the clinical and angiographic setting, until further scientific outbrakes.

Use of Intracoronary Thrombolysis for Huge Thrombus Burden in an Ectatic Right Coronary Artery

Managing a high intracoronary (IC) thrombus burden is a major challenge in patients with ectatic coronary arteries who present with an ST-elevation myocardial infarction (STEMI). We report a 45-year-old male patient who presented to the Department of Medicine, Sultan Qaboos University Hospital, Muscat, Oman, in 2017 with an inferior STEMI. Coronary angiography revealed ectatic coronary arteries with an occluded right coronary artery (RCA). The RCA had a massive thrombus burden that did not resolve with aspiration thrombectomy or balloon angioplasty. Subsequently, IC thrombolysis was administered resulting in significant reperfusion. During the course of his treatment, the patient suffered from intracranial bleeding as a complication; however, he recovered completely with no residual neurological sequelae. This case report demonstrates that IC thrombolysis is a valid option in patients with a massive thrombus burden in the setting of a STEMI, albeit with an increased risk of major bleeding.

The role of intracoronary thrombolysis in selected patients presenting with ST-elevation myocardial infarction: a case series

Background

Primary percutaneous coronary intervention (PCI) is the cornerstone of management for ST-elevation myocardial infarction (STEMI). However, large intracoronary thrombus burden complicates up to 70% of STEMI cases. Adjunct therapies described to address intracoronary thrombus include manual and mechanical thrombectomy, use of distal protection device and intracoronary anti-thrombotic therapies.

Case summary

This series demonstrates the use of intracoronary thrombolysis in the setting of large coronary thrombus, bifurcation lesions with vessel size mismatch, diffuse thrombosis without underlying plaque rupture, and improving coronary flow to allow vessel wiring and proceeding to definitive revascularization.

Discussion

Larger intracoronary thrombus burden correlates with greater infarct size, distal embolization, and the associated no-reflow phenomena, and propagates stent thrombosis, with subsequent increase in mortality and major adverse cardiac events. Intracoronary thrombolysis may provide useful adjunct therapy in highly selected STEMI cases to reduce intracoronary thrombus and facilitate revascularization.

Delay in coronary artery bypass grafting for STEMI patients improves hospital morbidity and mortality

Objectives

The optimal timing of coronary artery bypass grafting (CABG) in patients with ST elevated acute myocardial infarction (STEMI) is unclear. The purpose of the study is to evaluate and compare the outcomes in STEMI patients who underwent CABG within the various time intervals within the first 7 days of either emergent or urgent hospital admission.

Methods

Patients aged 30 years old and older diagnosed with STEMI who underwent CABG within first 7 days after non-elective hospital admission were selected from the National Inpatient Sample 2010–2014 using the appropriate ICD-9-CM diagnosis and procedure codes. These patients were divided into 3 cohorts based on timing of surgery: within 24 h (group A), 2nd-3rd day (group B), and 4th–7th day (group C). The rates of postoperative complications, mortality, and postoperative hospital length of stay (LOS) were compared using the Chi-square test, multivariable logistic regression analysis, and Wilcoxon rank sum test.

Results

A total of 5963 patients were identified: group A = 28.5%, group B = 36.1%, group C = 35.4%. Mean age overall was 63.1 ± 11.1 years; 76.9% were males and 72.9% were whites. Compared to groups B and C, patients in group A were more likely to develop cardiac complications (OR [odds ratio] =1.33, 95%CI [confidence interval] 1.12–1.59 and OR = 1.39, 95%CI 1.17–1.67, respectively) and respiratory complications (OR = 1.31, 95%CI 1.13–1.51 and OR = 1.53, 95%CI 1.32–1.78, respectively). They were also more likely to have renal complications (OR = 1.31, 95%CI 1.11–1.54) and bleeding (OR = 1.20, 95%CI 1.05–1.37) than patients in group B and had a similar tendency compared to group C. We did not find significant differences in the above complications between groups B and C. Postoperative stroke and sternal wound infection rates were similar between all three groups. In-hospital mortality was also higher in group A (8.2%) compared to group B (3.5%) and group C (2.9%, P < 0.0001 for both); differences between groups B and C were not significant. This was confirmed in the multivariable logistic regression analysis with controlling for age, gender, race, the Elixhauser Comorbidity Index, and complications (group A vs B: OR = 1.85, 95%CI 1.52–2.25; group A vs C: OR = 2.21; 95%CI 1.82–2.68). Patients in group A had a significantly longer postoperative LOS (median 7 days with IQR [interquartile range] 5–10 days) compared to those in group B (median 6 days, IQR 5–8 days) and group C (median 6 days, IQR 4–8 days; P < 0.0001 for both).

Conclusions

The results of this study show that despite the urgency and severity of STEMI, patients who undergo CABG within the first 24 h after non-elective hospital admission have increased hospital morbidity and mortality. These findings suggest that a delay in surgery beyond the first 24 h may be beneficial to patient outcomes. Furthermore, there is a significant cost effectiveness when the patients delay surgery because the hospital length of stay is reduced as well as the subsequent hospital costs.

No-reflow phenomenon during percutaneous coronary intervention in a patient with polycythemia vera: A case report

RATIONALE

Acute myocardial infarction is the leading cause of mortality and morbidity in a patient with polycythemia vera (PV). However, the benefit of various percutaneous coronary intervention (PCI) technique on the patient with PV is relatively unexplored.

PATIENT CONCERN

A 46-year-old woman presented to the primary hospital complained about new-onset typical chest pain. Echocardiography examination showed inferior ST-elevation myocardial infarction (STEMIs) and increased cardiac markers. Complete blood count showed elevated hemoglobin, white blood cell, and platelet.

DIAGNOSIS

Coronary angiography revealed simultaneous total occlusion at proximal right coronary artery (RCA) and also at proximal left anterior descending (LAD) artery. Elevated hemoglobin and hematocrit with JAK2 mutation establish the diagnosis of PV.

INTERVENTIONS

We performed multi-vessel primary PCI by using direct stenting in RCA and aspiration thrombectomy in LAD after failed with balloon dilatation and direct stenting method. This procedure resulted in thrombolysis in myocardial infarction (TIMI)-3 flow in both coronary arteries. However, the no-reflow phenomenon occurred in the LAD, followed by ventricular fibrillation. After several attempts of resuscitation, thrombus aspiration, and low-dose intracoronary thrombolysis, the patient was returned to spontaneous circulation. The patient then received dual antiplatelet and cytoreductive therapy.

OUTCOMES

The patient clinical condition and laboratory finding were improved, and the patient was discharged on the 7th day after PCI.

LESSONS

Cardiologist should be aware of the no-reflow phenomenon risk in the patient with PV and STEMI. Direct stenting, intracoronary thrombectomy, and thrombolysis are preferable instead of balloon dilatation for PCI technique in this patient.

A novel automated lumen segmentation and classification algorithm for detection of irregular protrusion after stents deployment

BACKGROUND

Clinically, irregular protrusions and blockages after stent deployment can lead to significant adverse outcomes such as thrombotic reocclusion or restenosis. In this study, we propose a novel fully automated method for irregular lumen segmentation and normal/abnormal lumen classification.

METHODS

The proposed method consists of a lumen segmentation, feature extraction, and lumen classification. In total, 92 features were extracted to classify normal/abnormal lumen. The lumen classification method is a combination of supervised learning algorithm and feature selection that is a partition-membership filter method.

RESULTS

As the results, our proposed lumen segmentation method obtained the average of dice similarity coefficient (DSC) and the accuracy of proposed features and the random forest (RF) for normal/abnormal lumen classification as 97.6% and 98.2%, respectively.

CONCLUSIONS

Therefore, we can lead to better understanding of the overall vascular status and help to determine cardiovascular diagnosis.

The predictors of no reflow phenomenon after percutaneous coronary intervention in patients with ST elevation myocardial infarction: A meta-analysis

OBJECTIVE

To investigate the no reflow risk factors after percutaneous coronary intervention in ST elevation myocardial infarction patients.

METHOD

Sample size, mean±standard deviation (SD) or frequencies (percent) of normal and no reflow groups were extracted from each study.

RESULTS

Of 27 retrospective and prospective studies, we found that increasing risks of no reflow were associated with advanced age, male, family history of coronary artery disease, smoking, diabetes mellitus, hypertension, delayed reperfusion, killip class ≥2, elevated blood glucose, increased creatinine, elevated creatine kinase (CK), higher heart rate, decreased left ventricular ejection fraction (LVEF), collateral flow ≤1, longer lesion length, multivessel disease, reference luminal diameter, initial thrombolysis in myocardial infarction (TIMI) flow, and high thrombus burden. Moreover, initial TIMI flow ≤1 and high thrombus burden had the greater impact on no reflow (OR95%CI=3.83 [2.77-5.29], p<0.0001 and 3.69 [2.39-5.68], p<0.0001, respectively).

CONCLUSION

Our meta-analysis reveals that initial TIMI flow ≤1 and high thrombus burden are the most impacted no reflow risk factors.

Determinants of angiographic thrombus burden and impact of thrombus aspiration on outcome in young patients with ST-segment elevation myocardial infarction

OBJECTIVES

We aimed to investigate the determinants of thrombus burden (TB) and the impact of thrombus aspiration (TA) on outcome in young adults with ST segment elevation myocardial infarction (STEMI).

BACKGROUND

The determinants of TB in young STEMI patients are not fully understood now.

METHODS

The 182 young (age ≤ 45 years) STEMI patients, who underwent coronary angiography and percutaneous coronary intervention (PCI) in our hospital from January 2013 to September 2016, were included. Angiographic TB and impact of TA on major adverse cardiac events (MACEs) were evaluated. Median clinical follow-up period was 875 (641-1,052) days.

RESULTS

All patients were male, mean age was 40 ± 5 years. High thrombus burden (HTB) was evidenced in 100 (54.9%) patients. TA was performed in 62 out 100 (62%) patients with high TB (HTB) during PCI. The prevalence of hypertension was significantly higher in the HTB group than in the low thrombus burden (LTB) group (75 vs. 17%, P < 0.001). The proportion of smoking, alcohol consumption, and family history of premature coronary artery disease were similar between HTB and LTB groups. During follow-up, 2 patients died and 31 patients underwent repeat PCI. MACE rate was significantly higher in the HTB group than in the LTB group (24.0 vs. 9.8%, P = 0.012) and significantly lower in HTB patients with TA than HTB patients without TA (14.5 vs. 39.5%, P = 0.018).

CONCLUSIONS

Hypertension is an independent determinant of HTB and TA could be considered as an effective therapeutic option in young male STEMI patients with HTB.

Expression of matrix metalloproteinases-12 in ST-segment elevation myocardial infarction: A case-control study

Matrix metalloproteinases-12 (MMP12) can lead to degradation of elastin resulting in plaque destabilization and rupture. MMP12 also facilitates platelet aggregation, adhesion, and granule secretion. However, evidence in the literature related to the function of MMP12 in ST-segment elevation myocardial infarction (STEMI) is little. This study investigated the expression of MMP12 in human coronary thrombus and examined the relationship between plasma MMP12 and STEMI.Arterial plasma was obtained from 46 STEMI patients and 52 stable angina pectoris (SAP) patients and 30 controls with angiographically normal coronary arteries. Coronary thrombi were obtained from 26 STEMI patients with a large thrombus burden (LTB). The expression levels of MMP12 in coronary thrombus were analyzed by immunohistochemistry and immunofluorescence, reverse transcription-polymerase chain reaction (RT-PCR), Western blotting (WB) and casein zymography. In addition, MMP12 concentration measured by enzyme-linked immunosorbent assay (ELISA) and activity measured by fluorescence resonance energy transfer (FRET) were used to assess the levels in plasma.We confirmed the expression of MMP12 in human coronary thrombus. MMP12 was secreted mainly in active form of 45 kDa in coronary thrombus. In plasma samples of the STEMI group, MMP12 concentrations were found to be higher than the SAP group (5.030 ± 2.24 pg/mL vs 3.010 ± 1.99 pg/mL, P < .05) but with lower MMP12 activity (332 ± 77 RFU vs 458 ± 91 RFU, P < .05). Also, the STEMI group demonstrated much higher MMP12 concentrations than the normal coronary artery control group (5.030 ± 2.24 pg/mL vs 1.720 ± 0.51 pg/mL, P < .05) and with lower MMP12 activity (332 ± 77 RFU vs 549 ± 112 RFU, P < .05). In addition, the STEMI group had significantly higher tissue inhibitor of metalloproteinases-1 (TIMP1) concentration (573.40 ± 270.60 pg/mL) than SAP group (384.50 ± 147.70 pg/mL) and control group (219.90 ± 154.80 pg/mL, P < .05). The imbalance in MMP12/TIMP ratio was observed in the STEMI group compared with SAP and control group (P < .05).This study demonstrated that MMP12 exists in human coronary thrombus. Patients with STEMI have elevated plasma level of MMP12 and the imbalance of MMP12/TIMP1. These data supported that MMP12 might be of potential relevance in STEMI.

Matrix metalloproteinase12 facilitated platelet activation by shedding carcinoembryonic antigen related cell adhesion molecule1

Platelets express several MMPs that modulate their activation, which in turn regulates thrombosis, but the exact mechanism is unclear. This study evaluated the platelet expression of MMP12 and platelet activation by shedding CEACAM1 mediated by MMP12. Expression of MMP12 was measured by RT-PCR, Western blot (WB), and casein zymography in platelet from whole blood by gel filtration over plateletpheresis. The site of CEACAM1 cleavage by MMP12 was determined by high performance liquid chromatography (HPLC), mass spectrometry, WB and flow cytometry (FCM). Furthermore, the regulation of platelet aggregation, release and adhesion by MMP12-dependent shedding of platelet CEACAM1 was analyzed. We have observed that human platelets express MMP12. In addition, CEACAM1 as enzymatic substrates of MMP12 have also been found in this study. MMP12 can cleave the CEACAM1 exodomain at several sites and generated several short peptides. Among these fragments, one peptide, WYKG was identified, whose cutting sits were S66/W67 and A83/I84. We also found that MMP12 facilitated type I collagen induced platelet aggregation, adhesion and alpha granule secretion. Similarly, one short peptide, WYKG, facilitated type I collagen induced platelet alpha granule secretion. We conclude that platelet express MMP12 may facilitate platelet activation through shedding of CEACAM1.

A new cooperative approach for ST-elevation myocardial infarction patients to receive timely and effective percutaneous coronary reperfusion in China

Background

Acute myocardial infarction (AMI) is the most serious type of coronary heart disease. However, less than 30% of these patients have been treated effectively in China. Delayed treatment is a leading cause. This study aimed to evaluate a new regional cooperative model for improving the first medical contact-to-device time and the therapeutic effects on AMI patients.

Methods

A retrospective analysis of 458 ST-elevation myocardial infarction (STEMI) patients was performed. Patients were divided into two groups in terms of before or after the model were implemented. First medical contact-to-device time (FMC2D), Door to device time (D2D), referral time, cardiac functions, mean cost, days of hospitalization, and major adverse cardiac events (MACE) were analyzed.

Results

The mean FMC2D time, D2D time and referral time of the model group were significantly lower than the control group. The left ventricular ejection fraction of the model group increased but the left ventricular end-diastolic dimension decreased compared with the control group at 6 months after discharge. These results also showed that mean costs and days of hospitalization were reduced. The MACE rate was reduced in the model group.

Conclusions

These results suggested that the new model decreased the FMC2D time, which could improve the cardiac function and therapeutic effect of STEMI patients as well as decreased the financial burden.

Clinical and laboratory predictors of coronary slow flow in coronary angiography

Background:

The coronary slow-flow phenomenon (CSFP) is a multifactorial angiographic finding with no established pathogenesis.

Objective:

To investigate the role of clinical profile and laboratory findings in patients with CSFP.

Methods:

We prospectively recruited 69 patients with angiographically diagnosed CSFP and compared them with 88 patients with normal coronary flow. Demographic information, comorbidities and laboratory analysis, including complete blood count with differential, lipid profile and serum biochemical analysis, were documented and compared in univariate and multivariate analyses.

Results:

Patients with CSFP were more likely to be male and active smokers. Total cholesterol, triglyceride, hemoglobin and hematocrit, platelet count, mean platelet volume, platelet distribution width and red cell distribution width (RDW) were all higher in patients with CSFP. In multivariate regression analysis, including smoking, total cholesterol, hematocrit, fasting blood glucose and red cell distribution width, except fasting blood glucose, all variables were independently associated with CSFP. Receiver operating characteristic curve analysis revealed a cut-off point of 13.05% for RDW with a sensitivity of 74.6% and a specificity of 77.3% (p<0.001, AUC = 0.802) A cut-off value of 11.35% for PDW had a 89.9% sensitivity and 98.9% specificity for the prediction of CSFP (p<0.001, AUC = 0.970)

Conclusion:

The changes of circulating blood cell components in patients with CSFP may be indicative of underlying inflammation and endothelial dysfunction that should be investigated in experimental studies.

Intracoronary injection of tirofiban prevents microcirculation dysfunction during delayed percutaneous coronary intervention in patients with acute myocardial infarction

OBJECTIVE

To determine whether tirofiban can prevent microcirculation dysfunction during delayed percutaneous coronary intervention (PCI) of spontaneously recanalized and severe narrowing coronary artery in patients with acute myocardial infarction.

METHODS

62 patients who have a single angiographically confirmed narrowing culprit coronary artery for more than 75% between 7 and 14 days after the onset of acute myocardial infarction were randomly divided into the tirofiban group (32 cases) and the placebo group (30 cases). All the patients received measurement of the index of microcirculatory resistance (IMR) before tirofiban/placebo administration and PCI. After PCI, IMR value was measured again.

RESULTS

There was no significant variation between the two groups before PCI (11.67 ± 6.45 of placebo group vs. 14.65 ± 12.45 of tirofiban group, P=0.158). After PCI, the IMR value of the tirofiban group is significantly lower than that of the placebo group (23.63 ± 9.91 of placebo group vs. 16.75 ± 9.98 of tirofiban group, P=0.008).

CONCLUSIONS

Intracoronary injection of tirofiban can significantly prevent the abnormal increase of IMR value during delayed PCI in patients with acute myocardial infarction.