Thrombolysis for acute myocardial infarction

Treatment of intracranial aneurysms using the Tubridge flow diverter

OBJECTIVE

The Tubridge flow diverter (TFD) was recently developed to treat intracranial aneurysm (IA). In this study, we aimed to assess the safety and efficacy of this novel device.

METHODS

A retrospective cohort of consecutive patients with IA was recruited between June 2017 and February 2022. The studied outcomes were perioperative complications, clinical quality of life, and angiographic IA occlusion. Multivariate logistic regression was performed to explore the potential predictors of perioperative stroke events and IA occlusion. A comprehensive literature review was conducted across five databases for evidence synthesis.

RESULTS

Among the patients with IA in our cohort, 144 underwent successful TFD implantation. Postoperative stroke was observed in 11 (7.6%) patients, and 130 (90.3%) patients were discharged with modified Rankin scales (mRS) of ≤2. In the last clinical follow-up (mean, 16.9 months), 96.6% of the patients reported a satisfactory quality of life (mRS ≤2). IA occlusion was observed in 84.6% of the patients at the last angiographic follow-up (mean, 10.4 months). Aneurysmal subarachnoid hemorrhage [odds ratio (OR), 6.98; 95% confidence interval (CI), 1.11-43.91] and giant IA (OR, 5.63; 95% CI, 1.15-27.48) were associated with perioperative stroke events. The evidence synthesis found high rates of satisfactory quality of life (rate, 98.8%; 95% CI, 97.1-99.9%) and IA obliteration (rate, 78.5%; 95% CI, 74.0-82.7%) after TFD treatment. The pooled complication rate was 13.6% (95% CI, 10.9-16.5%).

CONCLUSIONS

This study identified a high rate of IA occlusion in patients who received TFD treatment. These patients also reported a satisfactory quality of life. Further studies in larger prospective cohorts with longer follow-up periods are warranted to verify our findings. Key message What is already known on this topic  Flow diverter (FD) devices are an optimal tool to modify hemodynamics and treat intracranial aneurysms (IAs). However, the safety and efficacy of a novel self-expanding FD, namely the Tubridge flow diverter (TFD), remain to be fully established owing to the short-term follow-up periods and limited sample size of existing studies. What this study adds  In our cohort of patients who received TFD treatment, 96.6% of patients reported satisfactory quality of life at the last clinical follow-up (mean, 16.9 months); and 84.6% of IAs were successfully occluded at the last angiographic follow-up (mean, 10.4 months). Our comprehensive review and evidence synthesis of existing studies on TFD found high rates of satisfactory quality of life (98.8%; 97.1-99.9%) and IA obliteration (78.5%; 74.0-82.7%). How this study might affect research, practice or policy  TFD demonstrated satisfactory performance in the treatment of IAs in our cohort. Studies with larger prospective cohorts and longer follow-up periods are warranted to further investigate this promising novel approach.

Effectiveness of Different Treatment Modalities in Initial and Chronic Phases of Thyroid Eye Disease: A Systematic Review With Meta-analysis

BACKGROUND

Thyroid eye disease (TED), a common extrathyroidal manifestation of Graves disease, poses significant management challenges due to potential disfigurement, visual impairment, and decreased quality of life. Uncertainties remain about the optimal treatment approach, especially regarding TED duration and its impact on outcomes.

OBJECTIVE

This meta-analysis evaluates the effects of various treatments on inflammatory markers and severity endpoints in TED, stratified by disease duration, distinguishing between treatments initiated within the first 6 months (initial phase) and those initiated thereafter (subacute/chronic phase).

METHODS

Following PRISMA guidelines, a systematic search of multiple electronic databases yielded 26 studies meeting predefined inclusion criteria. Methodological quality was assessed, and data were meticulously extracted and analyzed.

RESULTS

In the initial phase, treatments like corticosteroids and teprotumumab showed significant improvements in clinical activity score, proptosis, and diplopia. In the subacute/chronic phase, the efficacy of methylprednisolone and teprotumumab is reduced. A "critical window" effect was observed, with treatments showing diminished efficacy after 6 months of TED duration.

CONCLUSION

This meta-analysis highlights the importance of tailoring treatment strategies based on TED duration, emphasizing early interventions to maximize benefits. The findings guide clinicians in selecting optimal treatments and underscore the need for further research to refine evidence-based approaches, ultimately enhancing patient outcomes and quality of life.

Tenecteplase versus alteplase in treatment of acute ST-segment elevation myocardial infarction: A randomized non-inferiority trial

BACKGROUND

A phase II trial on recombinant human tenecteplase tissue-type plasminogen activator (rhTNK-tPA) has previously shown its preliminary efficacy in ST elevation myocardial infarction (STEMI) patients. This study was designed as a pivotal postmarketing trial to compare its efficacy and safety with rrecombinant human tissue-type plasminogen activator alteplase (rt-PA) in Chinese patients with STEMI.

METHODS

In this multicenter, randomized, open-label, non-inferiority trial, patients with acute STEMI were randomly assigned (1:1) to receive an intravenous bolus of 16 mg rhTNK-tPA or an intravenous bolus of 8 mg rt-PA followed by an infusion of 42 mg in 90 min. The primary endpoint was recanalization defined by thrombolysis in myocardial infarction (TIMI) flow grade 2 or 3. The secondary endpoint was clinically justified recanalization. Other endpoints included 30-day major adverse cardiovascular and cerebrovascular events (MACCEs) and safety endpoints.

RESULTS

From July 2016 to September 2019, 767 eligible patients were randomly assigned to receive rhTNK-tPA ( n = 384) or rt-PA ( n = 383). Among them, 369 patients had coronary angiography data on TIMI flow, and 711 patients had data on clinically justified recanalization. Both used a -15% difference as the non-inferiority efficacy margin. In comparison to rt-PA, both the proportion of patients with TIMI grade 2 or 3 flow (78.3% [148/189] vs. 81.7% [147/180]; differences: -3.4%; 95% confidence interval [CI]: -11.5%, 4.8%) and clinically justified recanalization (85.4% [305/357] vs. 85.9% [304/354]; difference: -0.5%; 95% CI: -5.6%, 4.7%) in the rhTNK-tPA group were non-inferior. The occurrence of 30-day MACCEs (10.2% [39/384] vs. 11.0% [42/383]; hazard ratio: 0.96; 95% CI: 0.61, 1.50) did not differ significantly between groups. No safety outcomes significantly differed between groups.

CONCLUSION

rhTNK-tPA was non-inferior to rt-PA in the effect of improving recanalization of the infarct-related artery, a validated surrogate of clinical outcomes, among Chinese patients with acute STEMI.

TRIAL REGISTRATION

www.ClinicalTrials.gov (No. NCT02835534).

[Proposal for initial management of uncomplicated ST elevation myocardial infarction in centers without percutaneous coronary intervention capacity in Peru]

ST-segment elevation myocardial infarction (STEMI) is a clinical entity whose adequate treatment will depend on its prompt recognition, accurate diagnosis, and management in reperfusion networks. The first contact with these patients is generally done in centers without reperfusion capacity, attended by non-cardiologist doctors, and in centers far from hospitals with greater resolution capacity, something that is well known in our country. This manuscript proposes a strategy for the diagnosis and treatment of STEMI in centers without percutaneous coronary intervention capacity of the public health system in Peru, emphasizing not losing sight of electrocardiographic patterns compatible with coronary artery occlusion, adequate fibrinolysis and management of its complications, the treatment of infarction in special populations and highlighting the importance of the pharmacoinvasive strategy as the main form of reperfusion treatment in our country.

Factors associated with prehospital delay in acute myocardial infarction in Maldives

BACKGROUND

Acute myocardial infarction (AMI) is the top cause of death in Maldives. Our study aims to determine the prehospital delay and its associated factors in AMI patients in Maldives.

METHODS

A cross-sectional study was conducted with 127 patients, divided into early (≤ 6 h) and delayed (> 6 h) presenters to the hospital. The data collection for the study was carried out by interviewing AMI patients, focusing on their socio-demographic characteristics, coronary artery disease risk factors, clinical symptoms, situational factors, and behavioral and cognitive responses to symptoms.

RESULTS

The median onset-to-door time was 230 (IQR 420) minutes. The mean age of AMI patients was 50.9 (SD ± 12.9) years old, and 39.4% of them had delayed presentation to the hospital. Smokers (adj OR = 0.3; 95% CI: 0.1, 0.9; P = 0.047) and those with previous episodes of chest pain or AMI (adj OR = 0.2; 95% CI: 0.03, 0.91; P = 0.038) were significant factors for early presentation to the hospital, while denial of symptoms (adj OR = 29.3; 95% CI: 1.6, 547.2; P = 0.024) and lack of knowledge (adj OR = 7.2; 95% CI: 1.77, 29.43; P = 0.006) led to a delayed decision to seek treatment. Situational factors such as onset at the workplace (adj OR = 5.8; 95% CI: 1.24, 26.83; P = 0.025) had lower odds of delay, whereas referral cases (adj OR = 7.7; 95% CI: 1.9, 30.94; P = 0.004) and use of sea ambulance (adj OR = 11.1; 95% CI: 2.8, 43.8; P = 0.001) were prone to delay in presentation to the hospital.

CONCLUSION

Sea ambulance, referral cases, lack of knowledge, and denial of symptoms are significant factors associated with prehospital delay among patients with AMI. Public awareness about the benefits of early presentation and improvement of the means of transportation between islands is suggested to improve emergency cardiac care in the country.

Thrombus composition and thrombolysis resistance in stroke

A State of the Art lecture titled "Thrombus Composition and Thrombolysis Resistance in Stroke" was presented at the ISTH Congress in 2022. Intravenous thrombolysis (IVT) remains the only pharmacologic option to re-establish cerebral perfusion at the acute phase of ischemic stroke. IVT is based on the administration of recombinant tissue plasminogen activator with the objective of dissolving fibrin, the major fibrillar protein component of thrombi. Almost 30 years on from its introduction, although the clinical benefits of IVT have been clearly demonstrated, IVT still suffers from a relatively low efficacy, with a rate of successful early recanalization below 50% overall. Analyses of thrombectomy-recovered acute ischemic stroke (AIS) thrombi have shown that apart from occlusion site, thrombus length, and collateral status, AIS thrombus structure and composition are also important modulators of IVT efficacy. In this article, after a brief presentation of IVT principle and current knowledge on IVT resistance, we review recent findings on how compaction and structural alterations of fibrin together with nonfibrin thrombus components such as neutrophil extracellular traps and von Willebrand factor interfere with IVT in AIS. We further discuss how these new insights could soon result in the development of original adjuvant therapies for improved IVT in AIS. Finally, we summarize relevant new data presented during the 2022 ISTH Congress.

Cell-Based and Selected Cell-Free Therapies for Myocardial Infarction: How Do They Compare to the Current Treatment Options?

Because of cardiomyocyte death or dysfunction frequently caused by myocardial infarction (MI), heart failure is a leading cause of morbidity and mortality in modern society. Paradoxically, only limited and non-curative therapies for heart failure or MI are currently available. As a result, over the past two decades research has focused on developing cell-based approaches promoting the regeneration of infarcted tissue. Cell-based therapies for myocardial regeneration include powerful candidates, such as multipotent stem cells (mesenchymal stem cells (MSCs), bone-marrow-derived stem cells, endothelial progenitor cells, and hematopoietic stem cells) and induced pluripotent stem cells (iPSCs). These possess unique properties, such as potency to differentiate into desired cell types, proliferation capacity, and patient specificity. Preclinical and clinical studies have demonstrated modest improvement in the myocardial regeneration and reduced infarcted areas upon transplantation of pluripotent or multipotent stem cells. Another cell population that need to be considered as a potential source for cardiac regeneration are telocytes found in different organs, including the heart. Their therapeutic effect has been studied in various heart pathologies, such as MI, arrhythmias, or atrial amyloidosis. The most recent cell-free therapeutic tool relies on the cardioprotective effect of complex cargo carried by small membrane-bound vesicles-exosomes-released from stem cells via exocytosis. The MSC/iPSC-derived exosomes could be considered a novel exosome-based therapy for cardiovascular diseases thanks to their unique content. There are also other cell-free approaches, e.g., gene therapy, or acellular cardiac patches. Therefore, our review provides the most recent insights into the novel strategies for myocardial repair based on the regenerative potential of different cell types and cell-free approaches.

Improving treatment for acute ischemic stroke—Clot busting innovation in the pipeline

Acute ischemic stroke is a consequence of disrupted blood flow to the brain, caused by thrombosis—the pathological formation of occlusive clots within blood vessels, which can embolize distally to downstream tissues and microvasculature. The highest priority of stroke treatment is the rapid removal of occlusive clots and restoration of tissue perfusion. Intravenous thrombolysis is the pharmacological standard-of-care for the dissolution of blood clots, wherein thrombolytic drugs are administered to restore vessel patency. While the introduction of recombinant tissue-plasminogen activator (rtPA) in 1996 demonstrated the benefit of acute thrombolysis for clot removal, this was countered by severe limitations in terms of patient eligibility, lytic efficacy, rethrombosis and safety implications. Development of safer and efficacious treatment strategies to improve clot lysis has not significantly progressed over many decades, due to the challenge of maintaining the necessary efficacy-safety balance for these therapies. As such, rtPA has remained the sole approved acute therapeutic for ischemic stroke for over 25 years. Attempts to improve thrombolysis with coadministration of adjunct antithrombotics has demonstrated benefit in coronary vessels, but remain contraindicated for stroke, given all currently approved antithrombotics adversely impact hemostasis, causing bleeding. This Perspective provides a brief history of stroke drug development, as well as an overview of several groups of emerging drugs which have the potential to improve thrombolytic strategies in the future. These include inhibitors of the platelet receptor glycoprotein VI and the signaling enzyme PI3-Kinase, novel anticoagulants derived from hematophagous creatures, and proteolysis-targeting chimeras.

Impact of Delayed Pain to Needle and Variable Door to Needle Time On In-Hospital Complications in Patients With ST-Elevation Myocardial Infarction Who Underwent Thrombolysis: A Single-Center Experience

Background Myocardial infarction is a life-threatening event, and timely intervention is essential to improve patient outcomes and mortality. Previous studies have shown that the time to thrombolysis should be less than 30 minutes of the patient's arrival at the emergency room. Pain-to-needle time is a time from onset of chest pain to the initiation of thrombolysis, and door-to-needle time is a time between arrival to the emergency room to initiation of thrombolytic treatment. Ideally, the target for door-to-needle time should be less than 30 minutes; however, it is unclear if the door-to-needle time has a significant impact on patients presenting later than three hours from the onset of pain. As many of the previous studies were conducted in first-world countries, with established emergency medical services (EMS) systems and pre-hospital ST-elevation myocardial infarction (STEMI) triages and protocols, the data is not completely generalizable to developing countries. We, therefore, looked for the impact of the shorter and longer door-to-needle times on patient outcomes who presented to the emergency room (ER) with delayed pain-to-needle times (more than three hours of pain onset).  Objective To determine the impact of delayed pain-to-needle time (PNT) with variable door-to-needle time (DNT) on in-hospital complications (post-infarct angina, heart failure, left ventricular dysfunction, and death) in patients with ST-elevation myocardial infarction (STEMI) who underwent thrombolysis. Methods and results A total of 300 STEMI patients who underwent thrombolysis within 12 hours of symptoms onset were included, which were divided into two groups based on PNT. These groups were further divided into subgroups based on DNT. The primary outcome was in-hospital complications between the two groups and between subgroups within each group. The pain-to-needle time was ≤3 hours in 73 (24.3%) patients and >3 hours in 227 (75.7%) patients. In-hospital complications were higher in group II with PNT >3 hours (p <0.05). On subgroup analysis, in-hospital complications were higher with longer door-to-needle time in group II (p<0.05); however, there was no difference in complications among group I. Conclusion Our study is consistent with the fact that shorter door-to-needle time, even in patients with delayed PNT (>3 hours), has a significant impact on in-hospital complications with no difference in mortality.

Dynamic Regulation of Cysteine Oxidation and Phosphorylation in Myocardial Ischemia-Reperfusion Injury

Myocardial ischemia-reperfusion (I/R) injury significantly alters heart function following infarct and increases the risk of heart failure. Many studies have sought to preserve irreplaceable myocardium, termed cardioprotection, but few, if any, treatments have yielded a substantial reduction in clinical I/R injury. More research is needed to fully understand the molecular pathways that govern cardioprotection. Redox mechanisms, specifically cysteine oxidations, are acute and key regulators of molecular signaling cascades mediated by kinases. Here, we review the role of reactive oxygen species in modifying cysteine residues and how these modifications affect kinase function to impact cardioprotection. This exciting area of research may provide novel insight into mechanisms and likely lead to new treatments for I/R injury.

Management of Cardiogenic Shock in Patients with Acute Myocardial Infarction

Acute myocardial infarction and cardiogenic shock (AMI-CS) is associated with significant morbidity and mortality. Early mechanical revascularization improves survival, and development of STEMI systems of care has increased the utilization of revascularization in AMI-CS from 19% in 2001 to 60% in 2014. Mechanical circulatory support devices are increasingly used to support and prevent hemodynamic collapse. These devices provide different levels of univentricular and biventricular support, have different mechanisms of actions, and provide different physiologic effects. Herein, the authors review the definition, incidence, pathophysiology, and treatment of AMI-CS.

Triggering acute pancreatitis complicated with acute myocardial infarction by marijuana: a rare case report

Marijuana is a widely used illicit substance among young adults and its abuse has been reported worldwide. Marijuana is a rare trigger of acute myocardial infarction and acute pancreatitis. We present a 25-year-old man with acute pancreatitis subsequently complicated by acute ST-elevation myocardial infarction (STEMI), which was associated with marijuana abuse. This case highlights the need and importance of awareness among public about this rare but potentially lethal adverse effect. Also, it draws attention when clinicians confront patients with history of substance abuse, they should be alert to the possibility of concurrent occurrence of serious medical conditions that may be adverse effects of substance use. Acute pancreatitis with concurrent acute STEMI is a rare situation but is a challenge for many emergency physicians, and it can lead to trouble outcomes if it not be quickly diagnosed and properly managed. We demonstrate successful management in this complicated patient with primary angioplasty.

Impact of public health emergency response to COVID-19 on management and outcome for NSTEMI patients in Beijing: A single-center historic control

BACKGROUND

During coronavirus disease 2019 (COVID-19) epidemic, reducing the number of invasive procedure and choosing conservative medication strategy for patients with non-ST-segment elevation myocardial infarction (NSTEMI) is unavoidable. Whether this relatively conservative strategy will impact in-hospital outcome for NSTEMI patients remains unclear.

METHODS AND RESULTS

The current study included all consecutive NSTEMI patients who visited the emergency department in Fuwai Hospital from February 1 to March 31, 2020 and all the NSTEMI patients in the same period of 2019 as a historical control. Very-high-risk patients were defined as clinical presentation of heart failure, cardiac shock, cardiac arrest, recurrent chest pain, and life-threatening arrhythmias. The primary outcome was in-hospital major adverse cardiac events (MACE), defined as a composite of all-cause death, recurrent myocardial infarction, or heart failure. A total of 115 NSTEMI patients were enrolled since the outbreak of COVID-19, and a total of 145 patients were included in the control group. There was a tendency toward higher MACE risk in 2020 compared with 2019 (18.3% vs. 11.7%, p = .14). Among very-high-risk patients, early percutaneous coronary intervention (PCI) strategy in 2019 was associated with reduced MACE risk compared with delayed PCI in 2020 (60.6% [20/33] in 2020 vs. 27.9% [12/43] in 2019, p = .01).

CONCLUSIONS

COVID-19 pandemic results in a significant reduction in immediate/early PCI and a trend toward higher adverse event rate during hospitalization, particular in very-high-risk patients.

Postconditioning with Nitrates Protects Against Myocardial Reperfusion Injury: A New Use for an Old Pharmacological Agent

Early reperfusion remains the key therapy to salvage viable myocardium and must be applied as soon as possible following an acute myocardial infarction (AMI) to attenuate the ischemic insult. However, reperfusion injury may develop following reintroduction of blood and oxygen to vulnerable myocytes, which results in more severe cell death than in the preceding ischemic episode. Ischemic postconditioning (I-PostC) provides a cardioprotective effect in combination with pharmacological agents. Although nitrates have been tested in many experimental and clinical studies of acute AMI to evaluate the cardioprotective effect, few investigations have been focused on nitrates postconditioning in patients undergoing percutaneous coronary intervention (PCI). This review presents the manifestations of myocardial reperfusion injury (RI) and potential mechanisms underlying it, and provides the mechanisms involved in the cardioprotection of I-PostC. We also present a new therapeutic approach to attenuate RI by use of an ‘old’ agent – nitrates – in AMI patients.

Acute Pancreatitis Masquerading as Inferior Wall Myocardial Infarction: A Review

A rare presentation of acute pancreatitis is with electrocardiographic (ECG) changes that mimic myocardial ischemia. We present a report of a patient that presented with hemodynamic instability and new ECG changes of ST segment elevations in contiguous leads II, III, and aVF mimicking an inferior wall myocardial infarction. Emergent coronary angiography showed no significant coronary obstruction, but it was followed by a left-sided hemiplegia with radiographic evidence of diffuse embolic stroke. The patient was later found to have an underlying diagnosis of pancreatitis. Additional history that later became available indicated a history of severe acute pancreatitis treated elsewhere a few months prior to the current admission. We present the first comprehensive review of the literature comprising 36 total cases with pancreatitis masquerading as acute myocardial infarction, with inferior wall STEMI pattern being the most frequent. We present this case to highlight the diagnostic dilemma posed by this masquerade of a high acuity myocardial infarction and to highlight alternative diagnoses to be considered in such clinical circumstances.

Targeted Treatment of Ischemic and Fibrotic Complications of Myocardial Infarction Using a Dual-Delivery Microgel Therapeutic

Myocardial infarction (MI), commonly known as a heart attack, affects millions of people worldwide and results in significant death and disabilities. A major cause of MI is fibrin-rich thrombus formation that occludes the coronary arteries, blocking blood flow to the heart and causing fibrin deposition. In treating MI, re-establishing blood flow is critical. However, ischemia reperfusion (I/R) injury itself can also occur and contributes to cardiac fibrosis. Fibrin-specific poly( N-isopropylacrylamide) nanogels (FSNs) comprised of a core-shell colloidal hydrogel architecture are utilized in this study to design a dual-delivery system that simultaneously addresses the need to (1) re-establish blood flow and (2) inhibit cardiac fibrosis following I/R injury. These therapeutic needs are met by controlling the release of a fibrinolytic protein, tissue plasminogen activator (tPA), and a small molecule cell contractility inhibitor (Y-27632). In vitro, tPA and Y-27632-loaded FSNs rapidly degrade fibrin and decrease cardiac cell stress fiber formation and connective tissue growth factor expression, which are both upregulated in cardiac fibrosis. In vivo, FSNs localize to fibrin in injured heart tissue and, when loaded with tPA and Y-27632, showed significant improvement in left ventricular ejection fraction 2 and 4 weeks post-I/R as well as significantly decreased infarct size, α-smooth muscle actin expression, and connective tissue growth factor expression 4 weeks post-I/R. Together, these data demonstrate the feasibility of this targeted therapeutic strategy to improve cardiac function following MI.

The evolution of the Helsinki frostbite management protocol

BACKGROUND

Severe frostbite can result in devastating injuries leading to significant morbidity and loss of function from distal extremity amputation. The modern day management approach to frostbite injuries is evolving from a historically very conservative approach to the increasingly reported use of early interventional angiography and fibrinolysis with tPA. The aim of this study was to evaluate the results of our frostbite treatment protocol introduced 3 years ago.

METHODS

All frostbite patients underwent first clinical and then Doppler ultrasound examination. Angiography was conducted if certain clinical criteria indicated a severe frostbite injury and if there were no contraindications to fibrinolysis. Intra-arterial tissue plasminogen activator (tPA) was then administered at 0.5-1mg/h proximal to the antecubital fossa (brachial artery) or popliteal fossa (femoral artery) if angiography confirmed thrombosis, as well as unfractionated intravenous heparin at 500 units/h. The vasodilator iloprost was administered intravenously (0.5-2.0ng/kg/min) in selected cases.

RESULTS

20 patients with frostbite were diagnosed between 2013-2016. Fourteen patients had a severe injury and angiography was performed in 10 cases. The total number of digits at risk was 111. Nine patients underwent fibrinolytic treatment with tPA (including one patient who received iloprost after initial non response to tPA), 3 patients were treated with iloprost alone and 2 patients received neither treatment modality (due to contraindications). The overall digital salvage rate was 74.8% and the Hennepin tissue salvage rate was 81.1%. One patient developed a catheter-site pseudoaneurysm that resolved after conservative treatment.

CONCLUSIONS

Prompt referral to a facility where interventional radiology and 24/7 laboratory services are available, and the combined use of tPA and iloprost, may improve outcome after severe frostbite.

Zebrafish model of photochemical thrombosis for translational research and thrombolytic screening in vivo

Acute thromboembolic diseases remain the major global cause of death or disability. Although an array of thrombolytic and antithrombotic drugs has been approved to treat or prevent thromboembolic diseases, many more drugs that target specific clotting mechanisms are under development. Here a novel zebrafish model of photochemical thrombosis is reported and its prospective application for the screening and preclinical testing of thrombolytic agents in vivo is demonstrated. Through photochemical excitation, a thrombus was induced to form at a selected section of the dorsal aorta of larval zebrafish, which had been injected with photosensitizers. Such photochemical thrombosis can be consistently controlled to occlude partially or completely the targeted blood vessel. Detailed mechanistic tests indicate that the zebrafish model of photochemical thrombosis exhibits essential features of classical coagulation and a thrombolytic pathway. For demonstration, tissue plasminogen activator (tPA), a clinically feasible thrombolytic agent, was shown to effectively dissolve photochemically induced blood clots. In light of the numerous unique advantages of zebrafish as a model organism, our approach is expected to benefit not only the development of novel thrombolytic and antithrombotic strategies but also the fundamental or translational research targeting hereditary thrombotic or coagulation disorders.

The barriers associated with emergency medical service use for acute coronary syndrome: the awareness and influence of an Australian public mass media campaign

BACKGROUND

Emergency medical services (EMS) transport to hospital is recommended in acute coronary syndrome (ACS) guidelines, but only half of patients with ACS currently use EMS. The recent Australian Warning Signs campaign conducted by the Heart Foundation addressed some of the known barriers against using EMS. Our aim was to examine the influence of awareness of the campaign on these barriers in patients with ACS.

METHODS

Interviews were conducted with patients admitted to an Australian tertiary hospital between July 2013 and April 2014 with a diagnosis of ACS. Patient selection criteria included: aged 35-75 years, competent to provide consent, English speaking, not in residential care and medically stable. Multivariable logistic regression was used to examine factors associated with EMS use.

RESULTS

Only 54% of the 199 patients with ACS interviewed used EMS for transport to hospital. Overall 64% of patients recalled seeing the campaign advertising, but this was not associated with increased EMS use (52.0%vs56.9%, p=0.49) or in the barriers against using EMS. A large proportion of patients (43%) using other transport thought it would be faster. Factors associated with EMS use for ACS were: age >65 years, ST-elevation myocardial infarction, a sudden onset of pain and experiencing vomiting.

CONCLUSION

In medically stable patients with ACS, awareness of the Australian Warning Signs campaign was not associated with increased use of EMS or a change in the barriers for EMS use. Future education strategies could emphasise the clinical role that EMS provide in ACS.

Remote ischemic preconditioning attenuates EGR-1 expression following myocardial ischemia reperfusion injury through activation of the JAK-STAT pathway

BACKGROUND/OBJECTIVES

Remote ischemic preconditioning (RIPC) protects the myocardium from ischemia/reperfusion (I/R) injury however the molecular pathways involved in cardioprotection are yet to be fully delineated. Transcription factor Early growth response-1 (Egr-1) is a key upstream activator in a variety of cardiovascular diseases. In this study, we elucidated the role of RIPC in modulating the regulation of Egr-1.

METHODS

This study subjected rats to transient blockade of the left anterior descending (LAD) coronary artery with or without prior RIPC of the hind-limb muscle and thereafter excised the heart 24h following surgical intervention. In vitro, rat cardiac myoblast H9c2 cells were exposed to ischemic preconditioning by subjecting them to 3cycles of alternating nitrogen-flushed hypoxia and normoxia. These preconditioned media were added to recipient H9c2 cells which were then subjected to 30min of hypoxia followed by 30min of normoxia to simulate myocardial I/R injury. Thereafter, the effects of RIPC on cell viability, apoptosis and inflammatory markers were assessed.

RESULTS

We showed reduced infarct size and suppressed Egr-1 in the heart of rats when RIPC was administered to the hind leg. In vitro, we showed that RIPC improved cell viability, reduced apoptosis and attenuated Egr-1 in recipient cells.

CONCLUSIONS

Selective inhibition of intracellular signaling pathways confirmed that RIPC increased production of intracellular nitric oxide (NO) and reactive oxygen species (ROS) via activation of the JAK-STAT pathway which then inactivated I/R-induced ERK 1/2 signaling pathways, ultimately leading to the suppression of Egr-1.

Identification of High-Risk Patients with Non-ST Segment Elevation Myocardial Infarction using Strain Doppler Echocardiography: Correlation with Cardiac Magnetic Resonance Imaging

Assessment of left ventricular (LV) function is important for decision-making and risk stratification in patients with acute coronary syndrome. Many patients with non-ST segment elevation myocardial infarction (NSTEMI) have substantial infarction, but these patients often do not reveal clinical signs of instability, and they rarely fulfill criteria for acute revascularization therapy.

AIM

This study evaluated the potential of strain Doppler echocardiography analysis for the assessment of LV infarct size when compared with standard two-dimensional echo and cardiac magnetic resonance (CMR) data.

METHODS

Thirty patients with NSTEMI were examined using echocardiography after hospitalization for 1.8 ± 1.1 days for the assessment of left ventricular ejection fraction, wall motion score index (WMSI), and LV global longitudinal strain (GLS). Infarct size was assessed using delayed enhancement CMR 6.97 ± 3.2 days after admission as a percentage of total myocardial volume.

RESULTS

GLS was performed in 30 patients, and 82.9% of the LV segments were accepted for GLS analysis. Comparisons between patients with a complete set of GLS and standard echo, GLS and CMR were performed. The linear relationship demonstrated moderately strong and significant associations between GLS and ejection fraction (EF) as determined using standard echo (r = 0.452, P = 0.012), WMSI (r = 0.462, P = 0.010), and the gold standard CMR-determined EF (r = 0.57, P < 0.001). Receiver operating characteristic curves were used to analyze the ability of GLS to evaluate infarct size. GLS was the best predictor of infarct size in a multivariate linear regression analysis (β = 1.51, P = 0.027). WMSI >1.125 and a GLS cutoff value of -11.29% identified patients with substantial infarction (≥12% of total myocardial volume measured using CMR) with accuracies of 76.7% and 80%, respectively. However, GLS remained the only independent predictor in a multivariate logistic regression analysis to identify an infarct size ≥12%.

CONCLUSION

GLS is a good predictor of infarct size in NSTEMI, and it may serve as a tool in conjunction with risk stratification scores for the selection of high-risk NSTEMI patients.

COHgb levels predict the long-term development of acute myocardial infarction in CO poisoning

BACKGROUND

There are several studies evaluating the cardiac effects of carbon monoxide (CO) poisoning during the acute period; however, the number of studies evaluating the long-term cardiac effects is limited.

OBJECTIVE

The present study aimed to evaluate the effects of blood carboxyhemoglobin (COHb) levels, elevated due to CO poisoning on the long-term development of acute myocardial infarction (AMI).

METHODS

This cross-sectional cohort study included a total of 1013 consecutive patients who presented to the emergency department (ED) due to CO poisoning, between January 2005 and December 2007. The diagnosis of CO poisoning was made according to the medical history and a COHb level of greater than 5%. In terms of AMI development, the patients were followed up for an average of 56 months.

RESULTS

At the end of follow-up, 100 (10%) of 1013 patients experienced AMI. Carboxyhemoglobin levels at the time of poisoning were higher among those who were diagnosed with AMI compared to those who were not (55%±6% vs 30%±7%; P<.001). Using a multivariate Cox proportional hazards model with forward stepwise method, age, COHb level, CO exposure time, and smoking remained associated with an increased risk of AMI after adjustment for the variables found to be statistically significant in a univariate analysis. According to a receiver operating characteristic curve analysis, the optimal cutoff value of COHb used to predict the development of AMI was found to be greater than 45%, with 98% sensitivity and 94.1% specificity.

CONCLUSION

In patients presenting to the ED with CO poisoning, COHb levels can be helpful for risk stratification in the long-term development of AMI.

Xylarinase: a novel clot busting enzyme from an endophytic fungus Xylaria curta

Xylarinase is a bi-functional fibrinolytic metalloprotease isolated from the culture filtrate of endophytic fungus Xylaria curta which is monomeric with a molecular mass of ∼33.76 kDa. The enzyme displayed both plasmin and tissue plasminogen activator like activity under in vitro conditions. It hydrolyses Aα and Bβ chains of the fibrinogen. Optimal fibrinolytic activity of xylarinase is observed at 35 °C, pH 8. Ca(2+) stimulated the fibrinolytic activity of xylarinase while Fe(2+) and Zn(2+) inhibited suggesting it to be a metalloprotease. The Km and Vmax values of xylarinase were 240.9 μM and 1.10 U/ml for fibrinogen and 246 μM and 1.22 U/ml for fibrin, respectively. Xylarinase was found to prolong the activated partial thromboplastin time and prothrombin time. The N-terminal sequence of xylarinase (SNGPLPGGVVWAG) did not show any homology with previously known fibrinolytic enzymes. Thus xylarinase is a novel fibrinolytic metalloprotease which could be possibly used as a new clot busting enzyme.

Does modern medicine increase life-expectancy: Quest for the Moon Rabbit?

The search for elixir of immortality has yielded mixed results. While some of the interventions like percutaneous coronary interventions and coronary artery bypass grafting have been a huge disappointment at least as far as prolongation of life is concerned, their absolute benefit is meager and that too in very sick patients. Cardiac specific drugs like statins and aspirin have fared slightly better, being useful in patients with manifest coronary artery disease, particularly in sicker populations although even their usefulness in primary prevention is rather low. The only strategies of proven benefit in primary/primordial prevention are pursuing a healthy life-style and its modification when appropriate, like cessation of smoking, weight reduction, increasing physical activity, eating a healthy diet and bringing blood pressure, serum cholesterol, and blood glucose under control.

A Review of Current Diagnosis, Investigation, and Management of Acute Coronary Syndromes in Elderly Patients

The elderly constitute a sizeable proportion of the acute coronary syndrome (ACS) population, and this population is continually increasing in number. Guideline-directed therapy is frequently underutilized in the elderly due to concerns about patient safety. However, studies suggest that this subgroup could benefit from many of the conventional and newer therapies available. This paper reviews current literature in the context of contemporary American and European guidance.

Cost-Effectiveness of Thrombolytic Therapy, Compared with Anticoagulants Therapy in the Treatment of Acute Myocardial Infarction in Albania

AIM: The study aim is to evaluate the cost-effectiveness of thrombolytic treatment in acute MI comparing with anticoagulants therapy and between each other thrombolytic (SK, r-Pa).MATERIAL AND METHODS: We used a prospective registry of all patients admitted for acute myocardial infarction in intensive care units in Tirana. The average drugs cost was calculated for the hospitalization period in Albanian money (ALL). Survival and life quality were estimated by phone contact 1 year after acute MI.RESULTS: Anticoagulant group cost is 23865.3 ALL (170.5€), SK group cost is 54148.63 ALL (386.7€), r-Pa group has a cost of 92184.90 ALL (658.5€). In the group treated with SK the hospital survival is 100%, while in the control group 88.8%. Reteplase group has a lower period of stay in hospital than SK group 13.04 days vs. 17.97 days, mean age in group treated with r-Pa is 64.29 ± 10.03 approximate with anticoagulant group mean age 64.17 ± 11.08; differ significantly with SK group mean age 56.75 ± 10.04. Survival after 1 year was 96.4% for r-Pa and 96.9% SK.CONCLUSIONS: SK and r-Pa are successful thrombolytics with high effectiveness. It is gained a higher survival with the thrombolytic treatments. Reteplase is well tolerated in older patients than SK, is easier to apply than Streptokinase, but has higher cost.

Long-term survival benefits of thrombolysis: the Royal College of General Practitioners' myocardial infarction study

OBJECTIVE

To investigate whether there is a long-term survival benefit from receipt of thrombolysis in routine care particularly pre-hospital thrombolysis, using 20 year mortality data from the RCGP myocardial infarction (MI) cohort study.

METHODS

During 1991-92 the RCGP MI study assessed GP delivery of thrombolysis. Participants who received pre-hospital thrombolysis (n = 290), thrombolysis in hospital (n = 781) or no thrombolysis (n = 2021) were followed and mortality data collected to June 2012. The relationship between thrombolysis and survival time was analysed using Cox regression at 28 days, 1, 5, 10, 15 years post-AMI, and at end of follow-up (~20 years post-AMI).

RESULTS

Compared to those who did not receive it, participants who received thrombolysis had a significant survival benefit at 28 days [adjusted hazard ratio (HR) 0.72, 95% confidence interval (CI): 0.58-0.90]; 1 year (adjusted HR 0.69, 95% CI: 0.57-0.83); 5 years (adjusted HR 0.76, 95% CI: 0.66-0.86); 10 years (adjusted HR 0.85, 95% CI: 0.77-0.95) and 15 years (adjusted HR 0.88, 95% CI: 0.80-0.96) post-AMI until end of follow-up (adjusted HR 0.92, 95% CI: 0.84-1.00). Pre versus in-hospital thrombolysis did not appear beneficial, although there was evidence among the pre-hospital group that short symptom onset-to-needle times conferred greater benefit.

CONCLUSIONS

We found substantial long-term survival benefits associated with thrombolysis when used in routine care. Although primary percutaneous coronary intervention (pPCI) is now the choice treatment, thrombolysis remains an important option when pPCI cannot be delivered within 120 minutes of diagnosis.

Comparison of the cytoplasmic and periplasmic production of reteplase in Escherichia coli

Reteplase is the recombinant type of tissue plasminogen activator variant. In this study, preplasmic and cytoplasmic (as inclusion body: IBs) production and activity of recombinant reteplase in E. coli were investigated and compared using a pET system (pET22b and pET15b). The cDNA of reteplase was cloned by polymerase chain reaction (PCR) amplification, sequenced, inserted into the vector pET 22b and pET15b, and expressed using isopropyl β-D-1-thiogalactopyranoside (IPTG). The recombinant plasmid was expressed in the form of inclusion body in pET 15b and in periplasmic space in pET22b. The obtained results of inclusion body extraction from recombinant pET22b (rpET22b) and recombinant pET15b (rpET15b) plasmids using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed a band of ~39 kD. However, the obtained results of periplasmic space extraction from rpET22b plasmid showed a very weak band, while cytoplasmic expression of reteplase (pET15b) produced a strong protein band confirmed with Western blotting. Consequently, our results demonstrated that the cytoplasmic expression system is efficient for the production of reteplase protein in prokaryote systems and a high amount of reteplase was obtained from the expressed proteins in the form of IBs. The obtained activity of rpET15b plasmid showed a higher enzyme absorbance in comparison to rpET22b plasmid. This suggests rpET15b as an appropriate candidate for reteplase production.

Recent advancements in tissue engineering for stem cell-based cardiac therapies

Advances in cardiac tissue engineering have recently focused on utilizing stem cells to regenerate infarcted and scarred myocardium. Due to their proliferative nature and tremendous potential for differentiation, stem cells are presently being investigated for clinical applications. Unfortunately, limiting factors such as massive cell death and poor retention have hampered clinical outcomes. Consequently, the development of an efficient delivery system for stem cells to the target site is essential. The use of innovative tissue engineering techniques has opened up new horizons within the field of cellular cardiomyoplasty. This paper will present a comprehensive overview of the recent advancements in stem cell technology destined for myocardial tissue repair. In addition, the multidisciplinary approach to tissue engineering presented here will provide the reader with insight into the clinical realization of cellular cardiomyoplasty.

Nanotheranostics for personalized medicine

The application of nanotechnology in the biomedical field, known as nanomedicine, has gained much interest in the recent past, as versatile strategy for selective drug delivery and diagnostic purposes. The already encouraging results obtained with monofunctional nanomedicines have directed the efforts of the scientists towards the creation of "nanotheranostics" (i.e. theranostic nanomedicines) which integrate imaging and therapeutic functions in a single platform. Nanotheranostics hold great promises because they combine the simultaneous non-invasive diagnosis and treatment of diseases with the exciting possibility to monitor in real time drug release and distribution, thus predicting and validating the effectiveness of the therapy. Due to these features nanotheranostics are extremely attractive for optimizing treatment outcomes in cancer and other severe diseases. The following step is the attempt to use nanotheranostics for performing a real personalized medicine which will tailor optimized treatment to each patient, taking into account the individual variability. Clinical application of nanotheranostics would enable earlier detection and treatment of diseases and earlier assessment of the response, thus allowing screening for patients which would potentially respond to therapy and have higher possibilities of a favorable outcome. This concept makes nanotheranostics extremely appealing to elaborate personalized therapeutic protocols for achieving the maximal benefit along with a high safety profile. Among the several systems developed up to now, this review focuses on the nanotheranostics which, due to the promising results, show the highest potential of translation to clinical applications and may transform into concrete practice the concept of personalized nanomedicine.

Effects of low frequency ultrasound on some properties of fibrinogen and its plasminolysis

Background

Pharmacological thrombolysis with streptokinase, urokinase or tissue activator of plasminogen (t-PA), and mechanical interventions are frequently used in the treatment of both arterial and venous thrombotic diseases. It has been previously reported that application of ultrasound as an adjunct to thrombolytic therapy offers unique potential to improve effectiveness. However, little is known about effects of the ultrasound on proteins of blood coagulation and fibrinolysis. Here, we investigated the effects of the ultrasound on fibrinogen on processes of coagulation and fibrinogenolysis in an in vitro system.

Results

Our study demonstrated that low frequency high intensity pulse ultrasound (25.1 kHz, 48.4 W/cm2, duty 50%) induced denaturation of plasminogen and t-PA and fibrinogen aggregates formation in vitro. The aggregates were characterized by the loss of clotting ability and a greater rate of plasminolysis than native fibrinogen. We investigated the effect of the ultrasound on individual proteins. In case of plasminogen and t-PA, ultrasound led to a decrease of the fibrinogenolysis rate, while it increased the fibrinogenolysis rate in case of fibrinogen. It has been shown that upon ultrasound treatment of mixture fibrinogen or fibrin with plasminogen, t-PA, or both, the rate of proteolytic digestion of fibrin(ogen) increases too. It has been shown that summary effect on the fibrin(ogen) proteolytic degradation under the conditions for combined ultrasound treatment is determined exclusively by effect on fibrin(ogen).

Conclusions

The data presented here suggest that among proteins of fibrinolytic systems, the fibrinogen is one of the most sensitive proteins to the action of ultrasound. It has been shown in vitro that ultrasound induced fibrinogen aggregates formation, characterized by the loss of clotting ability and a greater rate of plasminolysis than native fibrinogen in different model systems and under different mode of ultrasound treatment. Under ultrasound treatment of plasminogen and/or t-PA in the presence of fibrin(ogen) the stabilizing effect fibrin(ogen) on given proteins was shown. On the other hand, an increase in the rate of fibrin(ogen) lysis was observed due to both the change in the substrate structure and promoting of the protein-protein complexes formation.

Adjunctive transcutaneous ultrasound with thrombolysis: results of the PLUS (Perfusion by ThromboLytic and UltraSound) trial

OBJECTIVES

We investigated whether transcutaneous ultrasound (TUS) augments coronary thrombolysis and achieves higher rates of Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 and ST-segment resolution in patients with ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

In animal coronary and peripheral artery thrombosis models, low-frequency TUS enhances and accelerates thrombolysis.

METHODS

In a double-blind, randomized, controlled international clinical trial, 396 patients with STEMI < or =6 h were randomized to thrombolysis alone or thrombolysis plus TUS. The 60 minute TIMI flow grade, ST-segment resolution (primary end points) and other angiographic, electrocardiographic, and clinical outcomes were compared between treatment groups.

RESULTS

The trial was halted after Safety and Efficacy Monitoring Committee interim analysis that demonstrated lack of treatment efficacy. In total, 360 patients were evaluable for angiographic, electrocardiographic, or clinical end points. Sixty minutes after thrombolytic administration, the proportion of patients achieving TIMI flow grade 3 did not differ between TUS and control groups (40.7% vs. 48.5%, respectively; p = 0.10). Achievement of >50% ST-segment resolution at 60 min did not differ between TUS and control groups (53.2% vs. 50.0%; p = 0.93). Thirty-day mortality and composite clinical events-death, reinfarction, recurrent ischemia, stroke, major bleed, left ventricular rupture (9.7 % vs. 10.2%; p = 0.88)-did not differ between TUS and control patients.

CONCLUSIONS

Thrombolysis plus TUS failed to improve 60-min TIMI flow grade or ST-segment resolution versus thrombolysis alone.

Opioid receptor agonist reduces myocardial ischemic injury when administered during early phase of myocardial ischemia

AIM OF THE STUDY

Postresuscitation myocardial dysfunction is one of the leading causes of early death after initial success of resuscitation, the mechanisms of postresuscitation myocardial dysfunction remain controversial. We hypothesize that ischemia injury, rather than reperfusion injury is the major cause of postresuscitation myocardial dysfunction. We proposed to investigate the separate effects of ischemia and reperfusion injury on postresuscitation myocardial dysfunction.

METHODS

Thirty-three Langendorff-perfused isolated rat hearts were subjected to 15 min of global ischemia followed by 120 min of reperfusion. Pentazocine was utilized as a myocardial protective agent, either before ischemia or during reperfusion. All hearts were randomized into 3 groups: (1) "ischemia protection", in which pentazocine was infused 10 min prior to global ischemia, (2) "reperfusion protection", in which pentazocine was infused during 2h of reperfusion and (3) "control", with no pentazocine infusion. Left ventricular (LV) functions were measured by the maximal rate of LV pressure rise (dP/dt(max)) and decline (-dP/dt(max)), the maximal LV diastolic pressure (LVDP). The incidences of postischemic arrhythmias were measured.

RESULTS

When pentazocine was administered before onset of ischemia, the LV systolic and diastolic functions were significantly greater, and the postischemic arrhythmias were significantly less in comparison to those with reperfusion protection (p<0.05) and the control group (p<0.05).

CONCLUSIONS

In this model, the severity of postischemic myocardial dysfunction was less when the heart was protected during ischemia. Ischemia injury may therefore be the major cause of postresuscitation myocardial dysfunction.

Pharmacogenetics in cardiovascular antithrombotic therapy

Thrombosis is the most important underlying mechanism of coronary artery disease and embolic stroke. Hence, antithrombotic therapy is widely used in these scenarios. However, not all patients achieve the same degree of benefit from antithrombotic agents, and a considerable number of treated patients will continue to experience a new thrombotic event. Such lack of clinical benefit may be related to a wide variability of responses to antithrombotic treatment among individuals (i.e., interindividual heterogeneity). Several factors have been identified in this interindividual heterogeneity in response to antithrombotic treatment. Pharmacogenetics has emerged as a field that identifies specific gene variants able to explain the variability in patient response to a given drug. Polymorphisms affecting the disposition, metabolism, transporters, or targets of a drug all can be implicated in the modification of an individual's antithrombotic drug response and therefore the safety and efficacy of the aforementioned drug. The present paper reviews the modulating role of different polymorphisms on individuals' responses to antithrombotic drugs commonly used in clinical practice.

Catheter-directed thrombolysis with the Endowave system in the treatment of acute massive pulmonary embolism: a retrospective multicenter case series

PURPOSE

To evaluate the efficacy of thrombolysis with the EndoWave peripheral infusion system in the treatment of patients with massive pulmonary embolism (PE) as compared to patients treated with catheter-directed thrombolysis.

MATERIALS AND METHODS

Ten patients (five men and five women; age range, 31-85 years; mean age, 54.20 years) with massive acute PE (17 lesions) were treated with ultrasonography (US)-assisted catheter-directed thrombolysis with the Endowave system. All patients had hypoxia and dyspnea. No patient had contraindication for thrombolysis. Angiographic findings, duration of lysis, dose of thrombolytics used, and procedural complications were recorded. Thrombolytics used were urokinase, tissue-type plasminogen activator (tPA), and Reteplase.

RESULTS

Complete thrombus removal was achieved in 13 of the 17 lesions (76%), near complete thrombolysis was achieved in three lesions (18%), and partial thrombolysis was achieved in one lesion (6%). The mean time of thrombolysis was 24.76 hours +/- 8.44 (median, 24 hours). The mean dose of tPA used for the Endowave group was 0.88 mg/h +/- 0.19 (13 lesions).

CONCLUSIONS

US-assisted catheter-directed thrombolysis is an effective method for treating massive thrombolysis. It has the potential to shorten the time of lysis and lower the dose of thrombolytics.

What is the optimal reperfusion strategy for elderly patients with acute MI?

The overview of the Fibrinolytic Therapy Trialists' (FTT) Collaborative Group showed that, in more than 3000 elderly patients, thrombolytic treatment is effective in reducing mortality of patients with acute myocardial infarction with ST elevation within 12 hours from the onset of symptoms. Small-scale clinical trials confirmed the superiority of primary percutaneous coronary intervention even in older patients. However, clinical practice largely differs from the setting of clinical trials and, specifically, with respect to primary percutaneous coronary intervention. As a consequence, the results observed with percutaneous coronary intervention in "real world" patients seem to be less favorable than those obtained in trials. For this reason, reperfusion therapy with fibrinolytic agents remains the first choice of therapy for ST elevation myocardial infarction in the majority of hospitals where direct percutaneous coronary intervention facilities are not available.

Thrombolytic therapy in children

Thrombolysis is increasingly considered a treatment option in newborns and children with arterial and venous thromboembolic events, or occluded central venous lines. However, no uniform recommendations are available with regard to indications, drug of choice, route of administration, and dosing regimen. Thus, several protocols are used for the different thrombolytic agents, leading to differing outcome with respect to the effectiveness of therapy and bleeding complications. This article will summarize the available information on the use of thrombolytic agents in newborns and children, focussing on the potential indications, efficacy and safety profiles, and evidence supporting dosing schedules.