Comparison of myocardial microcirculatory perfusion after catheter-administered intracoronary thrombolysis with anisodamine versus standard thrombus aspiration in patients with ST-elevation myocardial infarction

Intracoronary Thrombolysis in ST-Segment Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention: an Updated Meta-analysis of Randomized Controlled Trials

BACKGROUND

Primary percutaneous coronary intervention (PPCI) is the standard reperfusion treatment in ST-segment elevation myocardial infarction (STEMI). Intracoronary thrombolysis (ICT) may reduce thrombotic burden in the infarct-related artery, which is often responsible for microvascular obstruction and no-reflow.

METHODS

We conducted, according to the PRISMA statement, the largest meta-analysis to date of ICT as adjuvant therapy to PPCI. All relevant studies were identified by searching the PubMed, Scopus, Cochrane Library, and Web of Science.

RESULTS

Thirteen randomized controlled trials (RCTs) involving a total of 1876 patients were included. Compared to the control group, STEMI ICT-treated patients had fewer major adverse cardiac events (MACE) (OR 0.65, 95% CI, 0.48-0.86, P = 0.003) and an improved 6-month left ventricular ejection fraction (MD 3.78, 95% CI, 1.53-6.02, P = 0.0010). Indices of enhanced myocardial microcirculation were better with ICT (Post-PCI corrected thrombolysis in myocardial infarction (TIMI) frame count (MD - 3.57; 95% CI, - 5.00 to - 2.14, P < 0.00001); myocardial blush grade (MBG) 2/3 (OR 1.76; 95% CI, 1.16-2.69, P = 0.008), and complete ST-segment resolution (OR 1.97; 95% CI, 1.33-2.91, P = 0.0007)). The odds for major bleeding were comparable between the 2 groups (OR 1.27; 95% CI, 0.61-2.63, P = 0.53).

CONCLUSIONS

The present meta-analysis suggests that ICT was associated with improved MACE and myocardial microcirculation in STEMI patients undergoing PPCI, without significant increase in major bleeding. However, these findings necessitate confirmation in a contemporary large RCT.

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

INTRODUCTION

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

METHODS AND ANALYSIS

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

ETHICS AND DISSEMINATION

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

TRIAL REGISTRATION NUMBER

NCT05554588.

Update on the sources, pharmacokinetics, pharmacological action, and clinical application of anisodamine

Anisodamine is an anticholinergic drug extracted and isolated from the Anisodus tanguticus (Maxim.) Pascher of the Solanaceae family which is also a muscarinic receptor antagonist. Owing to the lack of natural sources of anisodamine, synthetic products are now used. Using ornithine and arginine as precursor compounds, putrescine is catalyzed by different enzymes and then undergoes a series of reactions to produce anisodamine. It has been used clinically to protect cardiac function and treat septic shock, acute pancreatitis, calculous renal colic, bronchial asthma, blood circulation disturbances, jaundice, analgesia, vertigo, acute poisoning, and other conditions.This review describes the relevant pharmacokinetic parameters. Anisodamine is poorly absorbed in the gastrointestinal tract, and it is not as effective as intravenous administration. For clinical medication, intravenous infusion should be used rather than rapid intravenous injection. With the advancement of research in recent years, the application scope of anisodamine has expanded, with significant developments and application values surging.This review systematically describes the sources, pharmacokinetics, pharmacological effects and clinical application of anisodamine, in order to provide a basis for clinical use.

Safety and effectiveness of nano composite hydrogel stent implantation in the treatment of coronary cardiovascular disease: A preclinical study

With the improvement of people's quality of life, various cardiovascular diseases are the most common diseases. Therefore, the main site of disease atherosclerosis is blood vessels, so we can see that its flow rate has obvious changes. Through the analysis of coronary heart disease, this paper studies the relationship between coronary artery disease and cardiovascular disease, which is helpful to evaluate the risk of disease, and also provides the best prevention and treatment plan to overcome cardiovascular disease. As the material of artificial cartilage repair, nanocomposite hydrogel has excellent application value and attraction, because nanocomposite hydrogel has a structure similar to the extracellular matrix of natural chondrocytes. The patients in the experimental group were treated with nano composite hydrogel stent implantation. The other group of patients used the traditional way to carry out the comparative experiment. In the perfusion data of each ventricular wall in the coronary angiography and anterior wall perfusion group, the percentage of lateral wall in the normal proportion was the highest, 69.2%, 59.3% in the anterior wall, 39.5% in the inferior wall, and 19.7% in the apical value and interval. The percentage of LAD stenosis in anterior wall perfusion was O. The highest percentage in the lateral wall was 69.2%, and the lowest in the septum and apex was 19.7%. Nanocomposite hydrogel stent implantation can effectively treat coronary heart disease. The research shows that it is safe and effective in application.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

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).

Safety and efficacy of intracoronary recombinant human prourokinase administration in patients with acute myocardial infarction and ST‑segment elevation: A meta‑analysis of randomized controlled trials

Slow blood flow or no reflow following percutaneous coronary intervention (PCI) in patients with acute ST-segment elevation myocardial infarction (STEMI) typically leads to an adverse prognosis. However, it is controversial whether to use prourokinase (Pro-UK) during PCI in patients with acute STEMI. The present meta-analysis compared the efficacy and safety of intracoronary Pro-UK administration in patients with acute STEMI. Published randomized controlled trials (RCTs) were analyzed to compare Pro-UK with non-Pro-UK treatment in patients with acute STEMI. PubMed, Cochrane Library and China National Knowledge Infrastructure were searched and meta-analysis was performed using Review Manager 5.3 software. A total of 13 RCTs were selected and 1,797 patients were considered in the meta-analysis, including 897 patients who received Pro-UK intervention and 900 patients who were in the control group. No significant heterogeneity was identified across these selected studies. Pro-UK therapy significantly decreased the incidence of major adverse cardiac events [risk ratio (RR), 0.68; 95% CI, 0.56-0.82, P<0.0001], left ventricular end-diastolic diameter [standardized mean difference (SMD), -0.26; 95% CI, -0.40 - -0.12; P=0.0003], corrected thrombolysis in myocardial infarction (TIMI) frame count [SMD, -0.45; 95% CI, -0.62 - -0.28; P<0.00001] and cardiac troponin I [SMD, -0.31; 95% CI, -0.46 - -0.17; P<0.0001]. In addition, Pro-UK administration increased TIMI grade 3 flow (RR, 1.16; 95% CI, 1.07-1.25; P=0.0003), TIMI myocardial perfusion grade 3 (RR: 1.39, 95% CI: 1.12-1.74, P=0.004), ST-segment resolution (RR, 1.23; 95% CI, 1.10-1.36; P=0.0002) and left ventricular ejection fraction (SMD, 0.38; 95% CI, 0.27-0.49; P<0.00001). No significant difference was identified in bleeding (RR, 1.12; 95% CI, 0.85-1.47; P=0.41). The present meta-analysis determined that intracoronary Pro-UK administration is efficacious and safe to decrease slow blood flow or no reflow phenomena following PCI and improve the prognosis of patients with acute STEMI.

Has low-dose intracoronary thrombolysis gained ground in primary percutaneous intervention?

Reducing thrombus burden would improve patient's outcomes. Low-dose intracoronary thrombolytic agent administration has been considered to improve myocardial microcirculation, cardiac function, and major adverse cardiovascular events in patients presenting with ST-segment elevation myocardial infarction and high thrombus burden. This paper discusses published meta-analyses on intracoronary thrombolysis in primary percutaneous intervention.

Functional angiography-derived index of microcirculatory resistance validated with microvascular obstruction in cardiac magnetic resonance after STEMI

INTRODUCTION AND OBJECTIVES

The index of microcirculatory resistance (IMR) measured after primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) is associated with microvascular obstruction (MVO) and adverse clinical events. To evaluate MVO after successful primary PCI for STEMI without pressure wires or hyperemic agents, we investigated the feasibility and usefulness of functional angiography-derived IMR (angio-IMR).

METHODS

The current study included a total of 285 STEMI patients who underwent primary PCI and cardiac magnetic resonance (CMR). Angio-IMR of the culprit vessel after successful primary PCI was calculated using commercial software. MVO, infarct size, and myocardial salvage index were assessed using CMR, which was obtained a median of 3.0 days [interquartile range, 3.0-5.0] after primary PCI.

RESULTS

Among the total population, 154 patients (54.0%) showed elevated angio-IMR (> 40 U) in the culprit vessel. MVO was significantly more prevalent in patients with angio-IMR> 40 U than in those with angio-IMR ≤ 40 U (88.3% vs 32.1%, P <.001). Infarct size, extent of MVO, and area at risk were significantly larger in patients with angio-IMR> 40 U than in those with angio-IMR ≤ 40 U (P <.001 for all). Angio-IMR showed a significantly higher discriminatory ability for the presence of MVO than thrombolysis in myocardial infarction flow grade or myocardial blush grade (area under the curve: 0.821, 0.504, and 0.496, respectively, P <.001).

CONCLUSIONS

Angio-IMR was significantly associated with CMR-derived infarct size, extent of MVO, and area at risk. An elevated angio-IMR (> 40 U) after primary PCI for STEMI was highly predictive of the presence of MVO in CMR. This trial was registered at ClnicalTrialsgov (Identifier: NCT04828681).

ERK/HIF-1α/VEGF pathway: a molecular target of ELABELA (ELA) peptide for attenuating cardiac ischemia-reperfusion injury in rats by promoting angiogenesis

BACKGROUND

Myocardial ischemia-reperfusion (I/R) injury is caused by a chain of events such as endothelial dysfunction. This study was conducted to investigate protective effects of ELABELA against myocardial I/R in Wistar rats and clarify its possible mechanisms. METHODS AND RESULTS: MI model was established based on the left anterior descending coronary artery ligation for 30 min. Then, 5 µg/kg of ELA peptide was intraperitoneally infused in rats once per day for 4 days. Western blot assay was used to assay the expression of t-ERK1/2, and p-ERK1/2 in different groups. The amount of myocardial capillary density, the expression levels of VEGF and HIF-1α were evaluated using immunohistochemistry assay. Masson's trichrome staining was utilized to assay cardiac interstitial fibrosis. The results showed that establishment of MI significantly enhanced cardiac interstitial fibrosis and changed p-ERK1/2/ t-ERK1/2 ratio. Likewise, ELA post-treatment markedly increased myocardial capillary density, the expression of several angiogenic factors (VEGF-A, HIF-1α), and reduced cardiac interstitial fibrosis by activation of ERK1/2 signaling pathways.

CONCLUSION

Collectively, ELA peptide has ability to reduce myocardial I/R injury by promoting angiogenesis and reducing cardiac interstitial fibrosis through activating ERK/HIF-1α/VEGF pathway.

IntraCoronary Artery Retrograde Thrombolysis vs. Thrombus Aspiration in ST-Segment Elevation Myocardial Infarction: Study Protocol for a Randomized Controlled Trial

Background

Type 2 diabetes (T2DM) is a major risk factor for myocardial infarction. Thrombus aspiration was considered a good way to deal with coronary thrombus in the treatment of acute myocardial infarction. However, recent studies have found that routine thrombus aspiration is not beneficial. This study is designed to investigate whether intracoronary artery retrograde thrombolysis (ICART) is more effective than thrombus aspiration or percutaneous transluminal coronary angioplasty (PTCA) in improving myocardial perfusion in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI).

Methods/Design

IntraCoronary Artery Retrograde Thrombolysis (ICART) vs. thrombus aspiration or PTCA in STEMI trial is a single-center, prospective, randomized open-label trial with blinded evaluation of endpoints. A total of 286 patients with STEMI undergoing PPCI are randomly assigned to two groups: ICART and thrombus aspiration or PTCA. The primary endpoint is the incidence of >70% ST-segment elevation resolution. Secondary outcomes include distal embolization, myocardial blush grade, thrombolysis in myocardial infarction (TIMI) flow grade, and in-hospital bleeding.

Discussion

The ICART trial is the first randomized clinical trial (RCT) to date to verify the effect of ICART vs. thrombus aspiration or PTCA on myocardial perfusion in patients with STEMI undergoing PPCI.

Clinical Trial Registration

[https://www.chictr.org.cn/], identifier [ChiCTR1900023849].

Intracoronary pharmacological therapy versus aspiration thrombectomy in STEMI (IPAT-STEMI): A systematic review and meta-analysis of randomized trials

BACKGROUND

Thrombus load in STEMI patients remains a challenge in practice. It aggravates coronary obstruction leading to impaired myocardial perfusion, worsened cardiac function, and adverse clinical outcomes. Various strategies have been advocated to reduce thrombus burden.

OBJECTIVES

This meta-analysis aimed to evaluate the effectiveness of intracoronary-administered thrombolytics or glycoprotein IIb/IIIa inhibitors (GPI) in comparison with aspiration thrombectomy (AT) as an adjunct to percutaneous coronary intervention (PCI) among patients presenting with ST-segment elevation myocardial infarction (STEMI).

METHODS

A comprehensive literature search for randomized trials that compared intracoronary-administered thrombolytics or GPI with AT in STEMI patients who underwent PCI, was conducted using various databases (e.g., MEDLINE, EMBASE, CENTRALE). Primary outcome was procedural measures (e.g., TIMI flow grade 3, TIMI myocardial perfusion grade (TMPG) 3, Myocardial blush grade (MBG) 2/3, ST-segment resolution (STR)).

RESULTS

Twelve randomized trials enrolled 1,466 patients: 696 were randomized to intracoronary-administered pharmacological interventions and 553 to AT. Patients randomized to PCI alone were excluded. Thrombolytics significantly improved TIMI flow grade 3 (odds ratio = 3.71, 95% CI: 1.85-7.45), complete STR (odds ratio = 3.64, 95% CI: 1.60-8.26), and TMPG 3 (odds ratio = 5.31, 95% CI: 2.48-11.36). Thrombolytics significantly reduced major adverse cardiovascular events (MACE) (odds ratio = 0.29, 95% CI: 0.13-0.65) without increasing bleeding risk. Trial sequential analysis assessment confirmed the superiority of thrombolytics for the primary outcome. Intracoronary GPI, either alone or combined with AT, did not improve procedural or clinical outcomes.

CONCLUSIONS

Compared with AT, intracoronary-administered thrombolytics significantly improved myocardial perfusion and MACE in STEMI patients.

Effects of Intracoronary Pro-urokinase or Tirofiban on Coronary Flow During Primary Percutaneous Coronary Intervention for Acute Myocardial Infarction: A Multi-Center, Placebo-Controlled, Single-Blind, Randomized Clinical Trial

Background: To determine whether intracoronary pro-urokinase or tirofiban improves myocardial reperfusion during primary percutaneous coronary intervention (PCI) for acute ST-segment elevation myocardial infarction (STEMI).

Methods: The study included patients with acute STEMI presenting within 12 h of symptoms at 11 hospitals in China between November 2015 and July 2017. Patients were randomized to receive selective intracoronary infusion of recombinant pro-urokinase (20 mg), tirofiban (10 μg/kg), or saline (20 mL) proximal to the infarct-related lesion over a 3-min period before stent implantation during primary PCI. The primary outcome was final corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) after PCI.

Results: This study included 345 patients. Initial angiography identified a high-grade thrombus (TIMI 4–5) in 80% of patients. Final CTFC after PCI was significantly lower in the pro-urokinase (P < 0.001) and tirofiban (P < 0.001) groups than in the saline group and similar between the pro-urokinase and tirofiban groups (P > 0.05). The pro-urokinase (P = 0.008) and tirofiban groups (P = 0.022) had more complete ST-segment resolution at 2 h and lower peak creatine kinase-MB levels after PCI than the saline group (P = 0.006 and P = 0.023). The 30-day incidence of major adverse cardiac events was 4.5% in the pro-urokinase group, 3.4% in the tirofiban group, and 2.6% in the saline group. The incidence of in-hospital TIMI major bleeding events was low and comparable between groups.

Conclusions: Adjunctive intracoronary pro-urokinase or tirofiban given before stent implantation during primary PCI improves myocardial reperfusion without increasing the incidence of major bleeding events.

Functional Coronary Angiography-Derived Index of Microcirculatory Resistance in Patients With ST-Segment Elevation Myocardial Infarction

OBJECTIVES

The aim of this study was to evaluate the diagnostic accuracy and prognostic implications of angiography-derived index of microcirculatory resistance (angio-IMR) in patients with ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

The index of microcirculatory resistance (IMR) is a reliable invasive measure of coronary microvascular dysfunction in patients with STEMI. A functional coronary angiography-derived method to estimate IMR is a wire- and hyperemic agent-free alternative to IMR.

METHODS

The study population consisted of 2 independent cohorts. The diagnostic cohort comprised patients with IMR from the culprit vessel immediately after successful primary percutaneous coronary intervention (n = 31). The prognostic cohort was patients with STEMI who were successfully treated with primary percutaneous coronary intervention and followed for 10 years from the index procedure (n = 309). Angio-IMR was calculated using computational flow and pressure simulation. The primary outcome was a composite of cardiac death and readmission for heart failure over 10 years of follow-up.

RESULTS

In the diagnostic cohort, angio-IMR correlated well with IMR (R = 0.778; P < 0.001). Sensitivity, specificity, accuracy, and area under the curve of angio-IMR to predict IMR >40 U were 75.0%, 84.2%, 80.6%, and 0.899 (95% confidence interval: 0.786-0.949), respectively. In the prognostic cohort, patients with angio-IMR >40 U showed significantly higher risk for cardiac death or readmission for heart failure than did those with angio-IMR ≤40 U (46.7% vs 16.6%; adjusted hazard ratio: 2.909; 95% CI: 1.670-5.067; P < 0.001). Angio-IMR >40 U was an independent predictor of cardiac death or readmission for heart failure (hazard ratio: 2.173; 95% CI: 1.157-4.079; P = 0.016) and showed incremental prognostic value compared with a model with clinical risk factors only (C index = 0.726 vs 0.666 [P < 0.001], net reclassification index = 0.704 [P < 0.001]).

CONCLUSIONS

Angio-IMR showed high correlation and diagnostic accuracy to predict IMR. Patients with STEMI with angio-IMR >40 U showed a significantly higher risk for cardiac death or readmission for heart failure than those with preserved angio-IMR values. (Prognostic Implication of Angiography-Derived IMR in STEMI Patients; NCT04628377).

Intracoronary Thrombolysis in Patients With ST-Segment Elevation Myocardial Infarction: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

The effects of intracoronary (IC) thrombolysis therapy in patients with ST-segment elevation myocardial infarction (STEMI) receiving primary percutaneous coronary intervention (PPCI) remain unclear.

METHODS

The meta-analysis was conducted according to the PRISMA statement. All relevant studies were identified by searching the PubMed, EMBASE, Cochrane Library, and Web of Science, with no time or language limitation. The pooled risk ratio (RR) and weighted mean difference (WMD) with a 95% CI were calculated.

RESULTS

Nine randomized controlled trials involving a total of 1341 patients were included. Compared with the control group, IC thrombolysis in patients with STEMI could reduce the incidence of major adverse cardiac events (MACE; RR 0.632, 95% CI, 0.474-0.843, P = .002) and improve left ventricular ejection fraction (RR 0.343, 95% CI, 0.178-0.509, P < .001) and myocardial microcirculation. However, there was no difference noted in the mortality (RR 0.759, 95% CI, 0.347-1.661, P = .490). The incidence rate of major bleeding and minor bleeding was comparable between the 2 groups.

CONCLUSIONS

Intracoronary thrombolysis was associated with improved MACE and myocardial microcirculation in patients with STEMI having PPCI, though it failed to improve mortality.

Index of microvascular resistance and outcomes following intra-coronary thrombolysis with percutaneous intervention in STEMI: a meta-analysis of randomized control trials

Microvascular obstruction following percutaneous coronary intervention (PCI) is highly prevalent and independently associated with adverse clinical outcomes. Microvascular obstruction is determined by index of the microvascular resistance. We performed a systematic review with meta-analysis of all published randomized clinical trials (RCTs) studying the effect of intra-coronary thrombolysis with PCI as compared to standard treatment among patients with ST-segment elevated myocardial infarction. We included 6 RCTs summing up to 947 patients in the final analysis. Intra-coronary thrombolysis resulted in significantly lower index of microvascular resistance [standardized mean difference: - 13.74, 95% confidence interval (CI): - 16.74 to - 10.73, P value < 0.001, I² = 0%]. There was no difference noted in the occurrence of major adverse cardiac events with intra-coronary thrombolysis as compared to standard treatment [Odds ratio:  0.71, 95% CI: 0.46-1.08, P value = 0.11,  I² = 0%]. The absence of heterogeneity deferred us from using dose-response analysis to account for altering dose used across studies. The results of the present meta-analysis highlights the role of intra-coronary thrombolysis in reducing microvascular obstruction. No effect of intra-coronary thrombolysis was noted on the occurrence of major adverse cardiac events.

Impact of Targeted Therapies for Coronary Microvascular Dysfunction as Assessed by the Index of Microcirculatory Resistance

Coronary microvascular dysfunction (CMD) has emerged as an important therapeutic target in the contemporary management of ischemic heart disease. However, due to a lack of a reliable traditional "gold standard" test for CMD, optimal treatment remains undefined. The index of microcirculatory resistance (IMR) is an intra-coronary wire-based technique that provides a more reliable and quantitative assessment of CMD and has been increasingly used as a preferred endpoint for evaluating CMD treatment strategies in recent studies. IMR can help diagnose CMD in angina patients with non-obstructive epicardial coronary disease, predict peri-procedural myocardial infarction in stable patients undergoing coronary stenting, and predict long-term prognosis after acute myocardial infarction. Studies of IMR in the setting of non-ST-elevation acute coronary syndromes are still lacking. This review critically appraises the current published literature evaluating targeted therapies for CMD using IMR as the assessment tool and provides insights into evidence gaps in this important field. The index of microcirculatory resistance has rapidly evolved from a research tool to being the new "gold standard" test for evaluating coronary microvascular dysfunction.

Efficacy and safety of intracoronary prourokinase during percutaneous coronary intervention in treating ST-segment elevation myocardial infarction patients: a randomized, controlled study

Background

Prourokinase is a single-chain plasminogen activator presenting with fewer hemorrhagic complications and reduced reocclusion rate compared with the conventional fibrinolytic agents in patients with coronary artery disease. However, prourokinase intracoronary injection during PCI for treating patients with ST-segment elevation myocardial infarction (STEMI) is rarely investigated. Therefore, this study aimed to evaluate the efficacy and safety of intracoronary prourokinase during the percutaneous coronary intervention (PCI) in treating STEMI patients.

Methods

Fifty STEMI patients who underwent primary PCI were consecutively enrolled and randomly assigned to intracoronary prourokinase group (N = 25) or control group (N = 25). During the primary PCI procedure, patients in the intracoronary prourokinase group received 10 ml prourokinase injection, while patients in control group received 10 ml saline injection as control. The primary endpoints were coronary physiological indexes, the secondary endpoints were angiographic assessments, myocardial infarct size/reperfusion assessment, cardiac function evaluations, major adverse coronary events (MACEs) and hemorrhagic complications. All patients were followed up for 3 months.

Results

Post PCI, the index of microcirculatory resistance (IMR) was decreased in intracoronary prourokinase group than that in control group (34.56 ± 7.48 vs. 49.00 ± 8.98, P < 0.001), while no difference of coronary flow reserve (CFR) (2.01 ± 0.32 vs. 1.88 ± 0.23, P = 0.267) or fractional flow reserve (FFR) (0.89 ± 0.05 vs. 0.87 ± 0.04, P = 0.121) was found between the two groups. The thrombolysis in myocardial infarction myocardial perfusion grade (TMPG) (P = 0.024), peak values of creatine kinase (CK) (P = 0.028), CK isoenzyme-MB (CK-MB) (P = 0.016), cardiac troponin I (cTnI) (P = 0.032) and complete ST-segment resolution (STR) (P = 0.005) were better in intracoronary prourokinase group compared with control group. At 3-months post PCI, left ventricular ejection fraction (LVEF) and wall motion score index (WMSI) were higher, while left ventricular end-diastolic diameter (LVEDd) was lower in intracoronary prourokinase group compared with control group (all P < 0.05). There was no difference in hemorrhagic complication or total MACE between the two groups.

Conclusion

Intracoronary prourokinase during PCI is more efficient and equally tolerant compared with PCI alone in treating STEMI patients.

Trial registration

Chinese Clinical Trial Registry ChiCTR1800016207. Prospectively registered.

Long-term outcome of patients with ST-segment elevation myocardial infarction treated with low-dose intracoronary thrombolysis during primary percutaneous coronary intervention: the 5-year results of the DISSOLUTION Trial

We tested the hypothesis that adjunctive thrombolysis at time of primary percutaneous coronary intervention (PCI) may affect favourably the long-term outcome of patients with ST elevation myocardial infarction (STEMI). To this end, we undertook a substudy of the DISSOLUTION (Delivery of thrombolytIcs before thrombectomy in patientS with ST-segment elevatiOn myocardiaL infarction Undergoing primary percuTaneous coronary interventION) trial. A total of 95 patients were randomized to local delivery of urokinase (n = 48) or placebo (n = 47). After PCI, a greater proportion of patients receiving urokinase had an improvement in myocardial perfusion, as indicated by a significantly higher final Thrombolysis in myocardial infarction (TIMI) grade 3, myocardial blush grade, and 60-min ST-segment resolution > 70%, as well as lower corrected TIMI frame count. At 1-year echocardiography, urokinase-treated patients exhibited significantly lower LV dimension, as well as higher LV ejection fraction and wall motion score index as compared with placebo-treated patients. At 5 years, major acute cardiovascular events (MACEs) were significantly less common in the urokinase group (P = 0.023), mainly due to a lower occurrence of hospitalisation for heart failure (P = 0.038). Multivariate analysis showed that factors independently associated with 5-year occurrence of MACEs were LV remodelling at 1-year echocardiography (P = 0.0001), 1-year LV ejection fraction (P = 0.0001), TIMI grade flow 0-2 (P = 0.0019), and age at time of PCI (P = 0.0173). In conclusion, low-dose intracoronary urokinase during primary PCI is associated with a more favourable 5-year outcome of patients with STEMI.

Comparison of myocardial microcirculatory perfusion after catheter-administered intracoronary thrombolysis with anisodamine versus standard thrombus aspiration in patients with ST-elevation myocardial infarction

OBJECTIVE

To evaluate efficacy, safety and feasibility of targeted intracoronary injection using pro-urokinase combined with anisodamine (TCA) versus thrombus aspiration (TA) in ST-elevation myocardial infarction (STEMI) patients with high thrombus loads.

BACKGROUND

The best method of avoiding thrombus detachment and stroke in PCI patients with high thrombus loads has not yet been established.

METHODS

STEMI patients receiving coronary artery angiography or percutaneous coronary intervention (CAG/PCI) with thrombus grade ≥ 3 from January 1, 2017 to June 30, 2018 were randomly assigned to targeted intracoronary thrombolysis (pro-urokinase and anisodamine via catheter (TCA) group), or the TA group which followed the standard thrombus aspiration procedure. Parameters compared included thrombus grade, index of microcirculatory resistance (IMR), postoperative myocardial SPECT, thrombosis in myocardial infarction (TIMI) scores including flow grade, corrected TIMI frame counts (CTFCs), and TIMI myocardial perfusion grade (TMPG). Adverse events were followed up within 3 months.

RESULTS

Thirty-nine patients were finally enrolled. In primary CAG/PCI, the TCA group had higher percentages of TIMI 3 flow and lower IMR values compared with the TA group. The ratio of TMPG 3 grade in the TCA group was higher in repeat CAG, and the perfusion descending area (PDA) presented by SPECT was lower than in the TA group. No significant difference was seen in major adverse coronary events (MACEs) or bleeding events at follow-up.

CONCLUSIONS

TCA appears to be effective, safe, and feasible for repatency and reduction of high thrombus burden in primary PCI and may protect myocardial microcirculation with improved outcomes.