Randomised trial of intravenous recombinant tissue-type plasminogen activator versus intravenous streptokinase in acute myocardial infarction. Report from the European Cooperative Study Group for Recombinant Tissue-type Plasminogen Activator

Evaluation of Drugs and Strategies for Treating Coronary Artery Ectasia: Update and Future Perspective

Context: Although the mechanisms involved in the pathogenesis of coronary artery ectasia (CAE) and its treatment methods are not known for certainty, increased inflammatory and coagulation responses can be responsible for the formation of ectasia due to vascular disorders. Evidence Acquisition: The content used in this paper was obtained from English language articles (2005 - 2020) retrieved from the PubMed database and Google scholar search engine using “coronary artery ectasia”, “treatment”, “drug”, and “aneurysm” keywords. Results: The proven effect of inflammation and coagulation in CAE has posed a significant challenge for disease management. Therefore, anti-inflammatory and anticoagulation drugs can be treatment options for these patients. Increased inflammatory responses and some coagulation factors in CAE patients is undeniable. The study of these two systems in CAE patients and the evaluation of drugs affecting these mechanisms to achieve a definitive conclusion requires further and more extensive studies. Conclusions: We evaluated the hypothesis that anti-inflammatory and anticoagulation drugs with improved vascular endothelial function may accelerate the healing process of CAE patients; thus, they may be treatment options. Finally, it can be said that identifying molecular pathways related to drugs can improve their effectiveness in treating patients and increasing their survival. In addition, identifying upstream and downstream pathways can help diagnose the disease pathogenesis in addition to treating patients.

Accelerated treatment with rtPA for pulmonary embolism induced circulatory arrest

Patients with circulatory arrest due to pulmonary embolism (PE) should be treated with fibrinolytics. Current guidelines do not specify which regimen to apply, and it has been suggested that the regimen of 100 mg rtPA/2 h should be used, because this is recommended for hemodynamic instable PE in the ESC/ERS Guideline. This two hour regimen, however, is incompatible with key principles of cardiopulmonary resuscitation (CPR), such as employment of interventions that allow fast evaluation of effectiveness, and limitation of the total duration of CPR to avoid poor neurological outcomes. Additionally, the low flow-state during CPR has important consequences for the pharmacokinetic properties of rtPA. Arguably, the volume of distribution is lower, the metabolism reduced and the half life time longer. Therefore, these changes largely discard the rationale to use high dosages of rtPA over a prolonged period of time. More importantly, these changes highlight that the guideline recommendations, based on studies in patients without circulatory arrest, cannot be easily translated to the situation of circulatory arrest. An accelerated regimen of rtPA (0.6 mg/kg/15 min., max 50 mg) is mentioned by the 2019 ESC/ERS Guideline. However, empirical support or a rationale is not provided. Due to the rarity of the situation and ethical difficulties associated with randomizing unconscious patients, a randomized head-to-head comparison between the two regimens is unlikely to ever be performed. With this comprehensive overview of the pharmacokinetics of rtPA and current literature, a strong rationale is provided that the accelerated protocol is the regimen of choice for patients with PE-induced circulatory arrest.

Characteristics of taste alterations in people receiving taxane-based chemotherapy and their association with appetite, weight, and quality of life

PURPOSE

There is limited evidence on the effect of chemotherapy-associated taste alteration. This study aimed to evaluate taste alteration characteristics in patients receiving taxane-based chemotherapy and investigate the association of taste alterations with appetite, weight, quality of life (QOL), and adverse events.

METHODS

This cross-sectional study evaluated 100 patients receiving paclitaxel, docetaxel, or nab-paclitaxel as monotherapy or combination therapy. Taste alterations were evaluated using taste recognition thresholds and severity and symptom scales. Taste recognition thresholds, symptoms, appetite, weight, and adverse events were compared between patients with and without taste alterations, and logistic regression analysis was performed to identify risk factors.

RESULTS

Of the 100 patients, 59% reported taste alterations. We found significantly elevated taste recognition thresholds (hypogeusia) for sweet, sour, and bitter tastes in the taste alteration group receiving nab-paclitaxel (p = 0.022, 0.020, and 0.039, respectively). The taste alteration group reported general taste alterations, decline in basic taste, and decreased appetite. Neither weight nor QOL was associated with taste alterations. Docetaxel therapy, previous chemotherapy, dry mouth, and peripheral neuropathy were significantly associated with taste alterations.

CONCLUSIONS

Almost 60% of patients receiving taxane-based regimens, especially docetaxel, reported taste alterations. Taste alteration affected the patient's appetite but did not affect the weight or QOL. Docetaxel therapy, previous chemotherapy, dry mouth, and peripheral neuropathy were independent risk factors for taste alterations.

How Much do we Know about ST Elevation?: Case Report of a Patient with Acute Coronary Syndrome in the Observation Ward

The identification of acute coronary syndrome continues to challenge even experienced clinicians. Emergency physicians have the responsibility to identify, treat and admit those patients with true acute coronary syndrome to the appropriate units. This article described a case of acute coronary syndrome that developed in the observation ward, with discussion on some recent reviews of standard electrocardiogram analysis. It is very important to point out that controversy over the measurement of ST elevation exists which may adversely affect patient management.

Spectrophotometric analysis of thrombolytic activity: SATA assay

Introduction: Measurement of thrombolytic activity is crucial for research and development of novel thrombolytics. It is a key factor in the assessment of the effectiveness of conventionally used thrombolytic therapies in the clinic. Previous methods used for the assessment of thrombolytic activity are often associated with some drawbacks such as being costly, time-consuming, complex with low accuracy. Here, we introduce a simple, economic, relatively accurate and fast method of spectrophotometric analysis of thrombolytic activity (SATA) assay, standardized by tissue plasminogen activator (tPA), which can quantitatively measure in vitro thrombolytic activity.

Methods: Blood clots were formed, uniformly, by mixing citrated whole blood with partial thromboplastin time (PTT) reagent, together with calcium chloride. Then, designated concentrations of tPA were added to the samples, and the released red blood cells from each clot were quantified using spectrophotometry (λ_max=405nm) as an indicator of thrombolytic activity. The accuracy of the method was tested by assessment of dose-responsibility against R² value obtained by linear equation and measurement of the limit of detection (LOD) and limit of quantification (LOQ). The SATA assay was validated in comparison with some currently used techniques.

Results: A linear relationship was obtained between different concentrations of tPA versus the spectrophotometric absorbance of the related dilutions of lysed clots, at λ_max=405nm. Calculated R² values were greater than 0.9; with LOD of 0.90 µg/mL of tPA (436.50IU) and LOQ of 2.99 µg/mL of tPA (1450.15IU).

Conclusion: Conclusively, the SATA assay is a very simple quantitative method with repeatable and reproducible results for estimating the potency of an unknown thrombolytic agent, and calculating the activity as delicate as 1 µg/mL of tPA (485 IU/mL of thrombolytic dose).

Recent advances in targeted delivery of tissue plasminogen activator for enhanced thrombolysis in ischaemic stroke

Tissue plasminogen activator (tPA) is the only FDA approved medical treatment for the ischaemic stroke. However, it associates with some inevitable limitations, including: short therapeutic window, extremely short half-life and low penetration in large clots. Systemic administration may lead to complications such as haemorrhagic conversion in the brain and relapse in the form of re-occlusion. Furthermore, ultrasound has been utilised in combination with contrast agents, echogenic liposome, microspheres or nanoparticles (NPs) carrying tPA for improving thrombolysis - an approach that has resulted in slight improvement of tPA delivery and facilitated thrombolysis. Most of these delivery systems are able to extend the circulating half-life and clot penetration of tPA. Various technologies employed for ameliorated thrombolytic therapy are in different phases, some are in final steps for clinical applications while some others are under investigations for their safety and efficacy in human cases. Here, recent progresses on the thrombolytic therapy using novel nano- and micro-systems incorporating tPA are articulated. Of these, liposomes and microspheres, polymeric NPs and magnetic nanoparticles (MNPs) are discussed. Key technologies implemented for efficient delivery of tPA and advanced thrombolytic therapy and their advantages/disadvantages are further expressed.

Short-term outcome of acute inferior wall myocardial infarction with emphasis on conduction blocks: a prospective observational study in Indian population

OBJECTIVE

The primary aim of the present study was to evaluate the complications, particularly conduction blocks, subsequent morbidity and mortality, and effect of thrombolytic therapy in Indian patients with inferior wall myocardial infarction (IWMI).

METHODS

This was a prospective, observational, single-center study conducted at LPS Institute of Cardiology, Kanpur, from December 2011 to May 2014. Patients who presented with typical chest pain and were subsequently diagnosed by standardized diagnostic criteria as having IWMI were enrolled. Patients were grouped on basis of conduction abnormalities, right ventricular (RV) infarction and thrombolytic treatment. Each group was analyzed for comparison of complication profile and mortality.

RESULTS

Of 573 patients with IWMI enrolled in the study (mean age: 58.90±12.3 years), 81.2% were male, 225 (39.3%) had conduction blocks, and 189 (32.9%) had RV infarction. In patients with conduction blocks, mortality occurred in 27 patients (12.0%) in contrast to 3.4% of patients without conduction block (p<0.03). Also, there were 27 cases of in-hospital mortality in patients with RV infarction compared with 9 cases in patients without RV infarction (p<0.01). Thrombolytic therapy significantly reduced mortality in patients with IWMI (p<0.001). A significant reduction was observed in cardiogenic shock (p=0.002), severe mitral regurgitation (p=0.007), and left ventricular failure (p<0.001) in patients undergoing thrombolytic therapy.

CONCLUSION

In Indian patients with IWMI, incidence of conduction blocks was higher than previously reported studies. Major complications such as atrioventricular block and RV infarction are associated with increased mortality and poor clinical outcomes. Thrombolytic therapy has a beneficial role in reduction of mortality rate and other complications.

Analytic Review: Thrombolytic Therapy in Acute Myocardial Infarction

The salvage of myocardium in the setting of acute myocardial infarction has long been a goal of physicians involved in the care of patients with coronary artery disease. Understanding the role of thrombosis in the pathogenesis of acute myocardial infarction has led the way to an entirely new approach to the treatment of this entity. Thrombolytic therapy has now become a widely used form of treatment with encouraging results. Both intravenous and intracoronary administration of thrombolytic agents have been shown to promote recanalization of acutely occluded coronary arteries. Results of studies using the clot-specific agent, tissue plasminogen activator, intravenously have been most encouraging; successful reperfusion has been obtained in approximately 70% of patients treated. In addition, a recent large-scale trial has shown a reduction in morbidity and mortality with the early use of thrombolytic agents.

Ongoing trials should help delineate the precise role and timing of these agents as the initial form of therapy for acute myocardial infarction. Other issues that remain unresolved are the frequency of restenosis and the role of percutaneous transluminal coronary angioplasty in addition to thrombolytic therapy in the treatment of acute myocardial infarction.

Thrombolytic Therapy: A Comprehensive Review of its Use in Clinical Medicine—Part I

In the first part of this comprehensive review of thrombolytic therapy in clinical medicine, we begin with a brief history of fibrinolysis, followed by a review of the components of die endogenous fibrinolytic system and the currently available plasminogen activators. An in-depth examination of thrombolysis in treatment of acute myocardial infarction follows, Including recommendations for management based on available clinical trial data. New developments in thrombolytic therapy are also discussed.

A study of coronary artery patency in relation to the index event in patients with myocardial infarction thrombolysed with streptokinase

BACKGROUND

Restoration of infarct vessel patency is the key treatment for acute ST-elevation myocardial infarction.

OBJECTIVE

The purpose of the study was to confirm the effectiveness of streptokinase (STK) for successful thrombolysis of the infarct-related artery (IRA) in patients with acute myocardial infarction (AMI), in relation to the time of the index event and age compared with newer thrombolytic agents, in a tertiary care centre.

METHODS

100 patients (77% male) thrombolysed with STK underwent coronary angiography within 48 h of presentation. Patency of the IRA was used to assess successful thrombolysis.

RESULTS

The mean pain-to-needle time was 3.24 h. 76 patients (76%) treated with thrombolysis had patent arteries with thrombolysis in myocardial infarction (TIMI) 2 or 3 flow. In subgroup analysis of time from the index event, patency rates were 83.3%, 77.5%, 68.7% and 40% in patients presenting within 0-2, 2-4, 4-6 and 6-12 h, respectively. In subgroup analysis, all patients less than 30 years of age had patent arteries with TIMI 2 or 3 flow. Coronary angiography showed the IRA was the left anterior descending artery (LAD) in 55%, the right coronary artery (RCA) in 33% and the left circumflex artery (LCX) in 12%. The patency rates of the LAD, RCA and LCX were 74.5%, 69.6% and 100%, respectively.

CONCLUSIONS

We found STK to be as effective as newer thrombolytic agents reported in other studies. In patients with AMI thrombolysed within 4 h, STK results in higher patency in young compared to older patients.

Spontaneous recovery of complete atrioventricular block complicating acute anterior wall ST elevation myocardial infarction

BACKGROUND

Complete atrioventricular block complicating acute anterior wall ST elevation myocardial infarction (MI) is classically considered one of the worst prognostic indicators.

METHODS

We present the case of a gentleman who developed complete atrioventricular block during the course of acute anterior wall ST elevation MI, and had spontaneous resolution of the same. Mechanisms of spontaneous resolution of complete atrioventricular block in the setting of acute MI are discussed. Attention is drawn to a subgroup of patients, albeit a minority, who have a better prognosis owing to reversible causes than classically expected and seen.

RESULTS

Clinical features suggested that this patient had reocclusion of the infarct-related artery after thrombolysis on presentation and spontaneous reperfusion.

CONCLUSION

Coronary angiography provides invaluable information for decision making in such clinical scenarios. Complete atrioventricular block due to reversible ischaemia produced by reocclusion of an infarct-related artery should be reversible by percutaneous coronary angioplasty of the infarct-related artery. We suggest that reversible causes be considered before attributing atrioventricular block to irreversible damage, which would require a permanent pacemaker implantation. This would be more significant in most of the developing world, where resources are scarce.

ST elevation measurements differ in patients with inferior myocardial infarction and right ventricular infarction

PURPOSE

Few studies specify the methods used to measure ST-segment elevation (STE). We therefore assessed differences in electrocardiography results depending on STE measurement methods for patients with inferior acute myocardial infarction (MI) and right ventricular infarction.

METHODS

This study was a retrospective analysis. The STE group consisted of 88 patients consecutively admitted to the emergency department with inferior ST elevation MI associated with occlusion of right coronary artery or left circumflex coronary artery who underwent primary percutaneous coronary intervention. The control group consisted of 109 patients with non-ST elevation MI who had occlusion of right coronary artery or left circumflex coronary artery and underwent percutaneous coronary intervention. Measurements were performed at the J point and 60 milliseconds later for limb lead and right precordial V(4) lead (V4R). The criterion of at least 1-mm STE in 2 consecutive leads was applied, and the diagnostic accuracy of V4R was calculated.

RESULTS

In the STE group, the measurements 60 milliseconds after the J point were significantly higher than measurements at the J point at the II, III, aVF, and V4R leads. In the control group, only the measurements at lead I differed significantly. There was a 5% difference in diagnostic sensitivity depending on the measuring points in the STE group, a 1% to 3% difference in the control group, and a 10% to 11% difference at the V4R lead.

CONCLUSION

In patients with inferior MI, STE depends on the method of measurement, indicating a need for the standardization of measurements.

The need for wider utilization of thrombolytic therapy

Antithrombotic and thrombolytic therapies confer clear net benefits in the treatment of acute myocardial infarction (AMI). Antithrombotic therapy with aspirin yields conclusive reductions in vascular mortality as well as reinfarction and stroke and should be administered to all patients with suspected AMI. There is presently no clear evidence of net benefits from adding either delayed subcutaneous or immediate intravenous heparin to an antithrombotic regimen of aspirin. Direct thrombin inhibitors have theoretical advantages over heparin as antithrombotic agents, but further data are needed from large-scale randomized trials to determine whether these agents confer net benefits when given in conjunction with aspirin. Thrombolytic therapy yields clear reductions in mortality and should be considered for all patients with suspected AMI presenting within 12 h of symptom onset. The differences in the efficacy, safety, or ease of administration of the various thrombolytic agents are small compared with the substantial benefits that would result from the wider use and earlier administration of any of the available agents. More widespread use of antithrombotic and thrombolytic therapies for AMI as well as earlier administration of thrombolytics could prevent tens of thousands of premature deaths annually in the United States alone, and hundreds of thousands worldwide.

Outcomes of primary percutaneous coronary intervention in acute myocardial infarction at Tehran Heart Center

OBJECTIVE

To describe our experience of primary angioplasty in ST-segment elevation myocardial infarction.

SUBJECTS AND METHODS

During a period of 2 years (April 2003 to May 2005), 83 high-risk patients presenting with acute ST-segment elevation myocardial infarction underwent primary angioplasty subject to availability of balloon dilation within 90 min of admission. In total, 73 stents were implanted; 69 were bare metal stents, while the remaining 4 were paclitaxel-eluting stents. Of the 83 patients, 8 presented with cardiogenic shock. Follow-up was for a period of 9 months. All angiographic, in-hospital and clinical outcomes were recorded on a database.

RESULTS

The procedure was successful in 79 of the 83 patients (95%) and unsuccessful in 4 (5%). Of these 4 patients, 3 died and 1 was treated medically. In 65 patients with zero perfusion, angioplasty was successful in 61 (93.8%), while it was completely successful (100%) in the remaining 18 patients with thrombolysis in myocardial infarction grade 3 perfusion. Vessel patency was achieved in 95% with thrombolysis in myocardial infarction grade 3 flow present in 93%. A total of 7 (8.5%) patients died while in the hospital. Of the 8 with initial cardiogenic shock on presentation, 4 (50%) died in the hospital and of the remaining 4, 1 was lost at 9-month follow-up. In-hospital reocclusion and reinfarction did not occur in any patient.

CONCLUSION

The results suggest that primary angioplasty is logistically feasible in our center with good clinical outcomes.

ST segment elevation differs depending on the method of measurement

OBJECTIVES

The literature seldom specifies the location or method of measurement of ST segment elevation (STE) for determining eligibility in reperfusion trials. The objective of this study was to assess if different methods of measurement of STE in precordial leads of patients with anterior acute myocardial infarction due to left anterior descending occlusion result in significantly different scores.

METHODS

This was a retrospective review of diagnostic electrocardiograms (ECGs) of consecutive patients presenting to our emergency department with acute myocardial infarction who had emergent primary percutaneous coronary intervention, left anterior descending occlusion, and no bundle branch block. STE was measured at the J point and at 60 milliseconds after the J point, relative to the PR segment, in leads V1-V6. STE by the two methods was compared for each lead, as were ST scores (sum of STE in leads V1-V6) and the sum of the STE in V2-V4. Eligibility for reperfusion therapy using 1-mm and 2-mm STE criteria in two consecutive anterior leads, as well as ST scores and the sum of the STE in V2-V4, were evaluated.

RESULTS

Thirty-seven ECGs were analyzed. Mean ST measurements in every lead were significantly lower when measured at the J point versus 60 milliseconds after the J point, as were ST scores (9.7 +/- 2.14 mm vs. 14.9 +/- 2.69 mm; p < 0.00001). Fewer ECGs met enrollment criteria when based on STE at the J point versus at 60 milliseconds after the J point. Fewer ECGs met an ST score of 6 mm when measured at the J point (70% vs. 88%).

CONCLUSIONS

In anterior STE myocardial infarction, STE measurements produce different results depending on the method of measurement. Future clinical trials should specify the method of measurement.

Thrombolytic Therapy: Current Clinical Practice

Thrombolytic therapy is an essential tool in the array of therapies designed to reopen arteries and veins occluded with thrombus. As the use of thrombolytic agents has entered mainstream practice, their application has expanded to include a wide variety of indications and settings. Thrombolytic agents are used in patients who have thrombosis of coronary arteries, precerebral and cerebral arteries, the aorta, iliac and mesenteric arteries, and peripheral arteries. The use of thrombolysis in venous thrombosis has included deep venous thrombosis of the upper and lower extremities and vena cava, mesenteric veins, cerebral veins, and central access catheters. Guidelines are available from the American College of Cardiology/American Heart Association regarding thrombolysis in myocardial infarction and from the American Stroke Association regarding thrombolysis in acute ischemic stroke.

Outcomes of thrombolytic therapy for acute myocardial infarction in women

Coronary artery disease is the leading cause of mortality in women older than 50 years of age. Thrombolytic therapy substantially reduces mortality in both women and men with ST-elevation acute myocardial infarction. However, the mortality risk reduction is somewhat lower in women, in spite of similar rates of successful coronary reperfusion after thrombolytic therapy in women and men. Hemorrhagic complications including stroke and other major bleeding appear to be more common in women, particularly elderly women. The risk of reinfarction after thrombolytic therapy also is greater in women compared with men. Because of the higher complication rates, women should be monitored closely after thrombolytic therapy. However, this lifesaving treatment should not be withheld or delayed in women when indicated.

Spontaneous intracerebral hemorrhage due to coagulation disorders

Although intracranial hemorrhage accounts for approximately 10 to 15% of all cases of stroke, it is associated with a high mortality rate. Bleeding disorders account for a small but significant risk factor associated with intracranial hemorrhage. In conditions such as hemophilia and acute leukemia associated with thrombocytopenia, massive intracranial hemorrhage is often the cause of death. The authors present a comprehensive review of both the physiology of hemostasis and the pathophysiology underlying spontaneous ICH due to coagulation disorders. These disorders are divided into acquired conditions, including iatrogenic and neoplastic coagulopathies, and congenital problems, including hemophilia and rarer diseases. The authors also discuss clinical features, diagnosis, and management of intracranial hemorrhage resulting from these bleeding disorders.

Synergistic treatment of ST-segment elevation myocardial infarction with pharmacoinvasive recanalization

Both pharmacologic and mechanical approaches designed to limit infarct size by recanalization of infarct-related arteries have reduced mortality associated with ST-segment elevation myocardial infarction (STEMI). Early efforts to combine the two were attenuated because of complications encountered. Primary percutaneous coronary intervention (PCI) and thrombolysis became viewed as alternative rather than complementary modalities. Time to recanalization and adequacy of restoration of perfusion were found to be pivotal determinants of a favorable outcome with either approach. Because pharmacologic intervention can be initiated immediately in virtually any hospital, it is a promising initial step. Because PCI proffers more complete recanalization, it may be a particularly salutary initial or subsequent step. Because of unavoidable delay often confronting implementation of PCI, optimal advantage may accrue from the use of both approaches in combination. We seek to emphasize the potential synergy by referring to the combined approach as "pharmacoinvasive recanalization" rather than by the conventional term "facilitated PCI." Virtually all patients with STEMI can benefit from prompt, sustained, and complete coronary recanalization. Thus, investigations focusing on identification of pharmacologic regimens that can safely initiate recanalization as early as possible, minimize bleeding, and broaden the temporal window available for efficacy of subsequent, optimally timed PCI should provide particularly valuable information.

Thrombolytic therapy: clinical applications

The therapeutic use of thrombolytic agents is the result of the increasing understanding of the pathophysiologic mechanisms underlying normal and deranged thrombosis and fibrinolysis. Plasminogen activators capable of increasing the production of plasmin exhibit considerable efficacy in the treatment of a variety of arterial and venous thrombotic disorders. The ideal thrombolytic agent has not been developed, but the desired clinical result of rapid opening of the thrombosed vessel without reocclusion, without activation of systemic fibrinogenolysis, and without a risk of hemorrhage are defined. Clinical studies clearly demonstrate that the addition of a variety of adjunctive agents to available thrombolytics enhances benefit without inordinate risk. The addition of intravascular angioplasty and stenting to thrombolysis increases the potential long-term benefit. Newer thrombolytic agents and new protocols for the use of existing therapies offer the promise of saving many who would otherwise succumb to coronary or cerebral arterial thrombosis or to venous thromboembolism.

[Questionnaire for patients with ischaemic cardiopathy on their reaction to various alarm symptoms]

OBJECTIVES

To find the degree of information that patients with ischaemic cardiopathy (IC) possess and their behaviour on alarm symptoms (thoracic pain of ischaemic profile under stress, at rest, worsening under stress and for over 20'), how they manage sub-lingual nitro-glycerine (SLNTG), and the source of their information.

DESIGN

Transversal descriptive study based on personal interview and our own questionnaire, from September to December 2001.

SETTING

Primary Care. Six clinics in three urban Health Areas.Participants. Randomised sample of 98 patients with IC (stable angina, unstable angina, angina with infarct).

MEASUREMENTS AND RESULTS

93 people (57 male, 36 women) were surveyed. Their average age was 71 19.34 had diagnosis of infarct. 17.2% (95% CI, 9.5%24.9%) had no SLNTG available. 78.5% (95% CI; 70.2%-86.8%) and 81.7% (95% CI; 73.8%-89.6%) of those with angina under stress or at rest, respectively, did not know when to attend the hospital Emergency department. 37.8% (95% CI, 26.8%-48.8%) with steady stress angina would attend a hospital or their doctor urgently. 100% of patients had received no information on angina at rest, under steady stress and for over 20'. There was no difference in behaviour before stress angina between patients who had been informed by Primary Care and those informed by Specialists. There was a difference, though, for good use of SLNTG between infarct and non-infarct patients (p = 0.003).

CONCLUSIONS

Our cardiopaths do not recognise alarm signals quickly; and so do not benefit as well as they might from hospital treatment. No doctor (Primary Care or specialist) informed them of the different ways to confront stable and unstable angina. Only a very small number used SLNTG in stress angina properly and knew when to attend Casualty. There is an urgent need to improve the health education of our cardiopaths.

Pharmacologic reperfusion therapy for acute myocardial infarction

Acute myocardial infarction (MI) remains a significant problem in terms of morbidity, mortality and healthcare costs. Pharmacologic reperfusion therapies for MI are becoming increasingly complex. This review therefore places contemporary pharmacologic MI developments into perspective. An historical overview of pharmacologic reperfusion therapy for MI is provided, followed by an analysis of current limitations, treatment options, and present and likely future pharmacologic therapies. Adjunctive percutaneous and other treatments are also discussed, to clarify what is becoming a rapidly changing field.

The effect of streptokinase neutralizing antibodies on fibrinolytic activity and reperfusion following streptokinase treatment in acute myocardial infarction

OBJECTIVES

To evaluate tissue plasminogen activator (tPA) activity as a measure of fibrinolytic response to treatment with streptokinase (SK) and to relate this to the effect of pretreatment SK antibodies and to successful reperfusion assessed by continuous computerized vectorcardiography (VCG).

SETTING

Umeå University Hospital.

SUBJECTS

A total of 104 patients with acute myocardial infarction (AMI) treated with SK and no history of previous SK treatment were studied. The tPA activity was measured 4 h after the start of treatment. The effect of pre-existing neutralizing antibodies to SK was analysed with a functional assay in pretreatment samples. Reperfusion was evaluated with VCG.

MAIN OUTCOME MEASURES

Successful reperfusion.

RESULTS

Fifty-five patients (53%) were classified as successfully reperfused. The risk for failed reperfusion was calculated in logistic regression models. In a univariate model, a borderline significant increase in the risk of failed reperfusion was observed in intermediate levels of SK neutralizing antibodies, but not in the highest levels. In a multivariate model, only high tPA activity, >25 U mL(-1), at 4 h (OR 0.17: 95% CI: 0.06-0.51) was associated with a higher rate of reperfusion whilst longer time to treatment (OR 1.17; 95% CI: 1.02-1.35) was associated with a higher risk of failed reperfusion. There was no significant correlation between neutralizing antibodies to SK and tPA activity at 4 h.

CONCLUSION

The SK treatment of AMI induced high levels of tPA activity which were associated with successful reperfusion. The effect of pre-existing SK antibodies had no significant influence on reperfusion and were not correlated to the fibrinolytic activity obtained.

Thrombolytic therapy

The therapeutic use of thrombolytic agents is the natural result of the increasing understanding of the pathophysiologic mechanisms underlying normal and deranged thrombosis and fibrinolysis. Plasminogen activators capable of increasing the production of plasmin exhibit considerable efficacy in the treatment of a variety of arterial and venous thrombotic disorders. The ideal thrombolytic agent has yet to be developed but the desired clinical result of rapid opening of the thrombosed vessel without reocclusion, without activation of systemic fibrinogenolysis, and without a risk of hemorrhage is well defined. Clinical studies clearly demonstrate that the addition of a variety of adjunctive agents to the available thrombolytics enhances benefit without inordinate risk. The addition of intravascular angioplasty and stenting to thrombolysis increases the potential long-term benefit. Newer thrombolytic agents and new protocols for the use of existing therapies offer the promise of saving many who would otherwise succumb to coronary or cerebral arterial thrombosis or to venous thromboembolism.

Compartment syndrome of the arm: a complication of noninvasive blood pressure monitoring during thrombolytic therapy for myocardial infarction

We report a rare case of tricep compartment syndrome caused by a hematoma which resulted from noninvasive blood pressure monitoring (NIBPM) during thrombolytic therapy. Clinicians administering thrombolytic agents should be aware of the risk of bleeding and compartment syndrome at the site of NIBPM. Appropriate preventative measures should be instituted when using automated pneumatic cuffs. An understanding of the pathophysiology and clinical presentation of an arm compartment syndrome will allow for prompt diagnosis and surgical treatment.

What's the point of ST elevation?

OBJECTIVE

The magnitude of ST elevation is a key piece of information in the decision to thrombolyse in acute myocardial infarction. The ability of clinicians to reliably identify ST elevation has not been previously assessed. This study sought to determine the variability in assessment of ST elevation in a group of doctors who commonly prescribe thrombolysis.

METHODS

The study was conducted in three large teaching hospitals in Manchester, England. A convenience sample of 63 SHOs and SpRs from emergency and general medicine were recruited. Each was shown three sample ECG complexes. They were asked to identify and quantify the degree of ST elevation. They then indicated the points on the ECG from which they measured ST elevation.

RESULTS

ST elevation was not identified in 12% of cases. Doctors used a wide variety of points on the ST segment to assess elevation, this resulted in a wide variation in the observed magnitude of ST elevation.

CONCLUSION

No guidance exists on where exactly ST elevation should be measured. This study shows a wide variation in practice. Protocol led thrombolysis decision pathways may be compromised by these findings.

Human plasma fibrinogen measurement derived from activated partial thromboplastin time clot formation

Prothrombin time-derived measurement of fibrinogen (PTd) has already been described. Activated partial thromboplastin time-derived measurement of fibrinogen (aPTTd) has not yet been clearly defined. Using an MDA II coagulometer (Organon Teknika, Durham, North Carolina, USA), we have therefore compared fibrinogen levels determined with Clauss, PTd, and aPTTd assays and an enzyme immunoassay (EIA) in 172 samples. Of these, 47 were from pre-operative controls, 18 from patients with liver disease, 28 from patients with hyperfibrinogenaemia, 33 from patients treated with vitamin K antagonists, 22 from patients treated with unfractionated heparin and 24 from haemophilic patients. Within the normal range, interassay and intra-assay variations were comparable. For control samples, PTd, aPTTd and Clauss assays were well correlated, without any systematic error. EIA was also correlated but values were slightly higher (mean of difference = 0.24). Pathological samples showed an overestimation of fibrinogen when using PTd measurements in patients treated with vitamin K antagonists, as well as when using aPTTd measurements in patients presenting with factor VIII and factor IX deficiencies. These results indicate that, despite expected financial savings, aPTTd fibrinogen measurements should not be used without restriction. PTd and aPTTd fibrinogen determinations are provided without any additional cost. Their comparison with Clauss fibrinogen results may constitute a validation tool or have additional diagnostic utility (e.g. identifying polymerization abnormalities in case of dissimilar results).

Does routine use of the 15-lead ECG improve the diagnosis of acute myocardial infarction in patients with chest pain?

OBJECTIVE

It has been suggested that the use of additional electrocardiogram leads might improve the diagnostic sensitivity of this test, thus potentially expanding eligibility for thrombolysis for patients suffering myocardial infarction. The aims of this study were to evaluate the role of the 15-lead electrocardiogram in the emergency department chest pain population and to determine whether the routine use of the extra leads expands the group of patients eligible to receive thrombolysis.

METHODS

Blinded, individual and independent analysis by two emergency physicians of paired 12- and 15-lead electrocardiograms from adult patients with a primary complaint of chest pain. The main outcome measure was the diagnosis of myocardial infarction eligible for thrombolysis. Data were analysed using descriptive statistics and kappa statistics for agreement between raters.

RESULTS

540 electrocardiograms (270 sets) were analysed. Myocardial infarction qualifying for thrombolysis was identified (by consensus) in 21 cases. In no case did the 15-lead electrocardiograph identify a myocardial infarction qualifying for thrombolysis that was not identified on the 12-lead electrocardiogram.

CONCLUSION

In this study, the 15-lead electrocardiogram did not increase the number of thrombolysis-eligible myocardial infarctions identified when compared with the 12-lead electrocardiogram. This study is limited by the small patient sample size, and a large multicentre trial is recommended to compare the 12- and 15-lead electrocardiograms in the emergency department population where the incidence of posterior and right-sided myocardial infarction is ultimately known.

Magnetic resonance imaging of cerebral hemorrhagic stroke

Despite a traditional perception of reliance on computed tomography and lack of acceptance of magnetic resonance imaging (MRI) for detecting acute hemorrhage, MRI appears to be used increasingly in hemorrhagic stroke. This review addresses the MRI findings of acute hemorrhagic stroke obtained using relatively new imaging techniques. These new techniques have resulted in more acute stroke patients undergoing MRI examination. New information about the frequency and appearance of hemorrhage is emerging: for example, approximately 15-26% of cases of acute cerebral infarctions appear to be complicated by intracerebral hemorrhage. The MRI appearances of hemorrhagic transformation of ischemic infarction, as well as acute hypertensive intracerebral hemorrhage, are discussed based on clinical, biochemical, and technical aspects.

Comparison of receptor-mediated endocytosis kinetics between wild-type t-PA and recombinant pamiteplase in isolated rat hepatocytes and liver cell plasma membranes

1. Differences in receptor-mediated endocytosis kinetics between pamiteplase, an engineered t-PA, and an unmodified rt-PA were examined using liver cell plasma membranes and isolated rat hepatocytes. 2. Whereas the binding site of pamiteplase on hepatocytes was the same as that of rt-PA, the Kd of pamiteplase was 5.1-7.7 times larger than that of rt-PA, indicating a lower affinity of pamiteplase for the t-PA receptor. 3. ke for pamiteplase measured using parenchymal cells or non-parenchymal cells was slightly smaller than that for rt-PA, whereas kon for pamiteplase were much lower than that of rt-PA, suggesting that the interaction between pamiteplase and the receptor is slower than that of rt-PA because of its structural modification. 4. Therefore, the difference in drug disposition between pamiteplase and rt-PA is mainly due to the difference in the hepatic clearance caused by a change in the interaction rate between the ligand and its cell-surface receptor.

Ten-year experience with early angioplasty in 759 patients with acute myocardial infarction

OBJECTIVES

How effective and safe is rescue percutaneous transluminal coronary angioplasty [PTCA] compared with primary PTCA, and is it cost effective?

BACKGROUND

In acute myocardial infarction (AMI), primary PTCA has been shown to be beneficial in terms of clinical outcome. In contrast, the value of rescue PTCA has not been established.

METHODS

In a retrospective analysis, we compared the angiographic and clinical outcomes of 317 consecutive patients who had rescue PTCA approximately 90 min after failed thrombolysis and 442 patients treated with primary PTCA. An estimation of interventional costs was compared with the strategies of primary and rescue PTCA or with the strategy of thrombolysis with rescue PTCA, when indicated.

RESULTS

Baseline characteristics between primary and rescue PTCA were comparable for most variables. Treatment delay was longer for patients who had rescue PTCA: 240 min. versus 195 min. Coronary patency after PTCA was comparable: 90.2% for rescue PTCA and 91.4% for primary PTCA (p = 0.67, power 71.9%). In-hospital mortality rates were 4.7% and 6.6%, respectively (p = 0.37). Also, the other complications were fairly similar during the in-hospital phase and during one-year follow-up. Predictors of death were age, infarct size, localization of AMI, failed PTCA and left main stem occlusion. The estimated interventional costs during one-year follow-up were $7,377 for primary PTCA and $8,246 for rescue PTCA: difference $869 (11.7%).

CONCLUSIONS

In this retrospective analysis of 759 patients with AMI, rescue angioplasty early after failed thrombolysis seems to be as effective and safe as primary PTCA. In the present evaluation, interventional costs of primary PTCA are less than those of rescue PTCA (p = 0.0001).

Rescue PTCA Following Failed Thrombolysis and Primary PTCA: A Retrospective Study of Angiographic and Clinical Outcome

Evidence is increasing that a patent culprit artery improves the prognosis of patients with acute myocardial infarction (AMI). Primary percutaneous transluminal coronary angioplasty (PTCA) has shown to be more effective than thrombolytic therapy alone. How effective is rescue PTCA after failed thrombolytic treatment? In a retrospective analysis, 176 consecutive patients with AMI and TIMI 0 or 1 perfusion grade were included. Patients had either rescue PTCA after failed thrombolysis (100 patients) or primary PTCA (76 patients). Angiographic data and in-hospital and 1-year outcome were analyzed. Comparison of baseline data of the two groups showed a higher proportion of long-standing angina and use of nitrates and aspirin in the primary PTCA group. Also, the delay between the onset of pain and PTCA was not significantly different, with a mean of 222 minutes for rescue PTCA and 245 minutes for primary PTCA (p = 0.52). The angiographic outcomes in the rescue PTCA group and the primary PTCA group were identical: The intervention was successful (TIMI 3 flow and residual stenosis <50%) in 86.0% and 85.5%, respectively. Complication rates of the procedure were also similar, except for bleeding complications. Blood transfusion was only needed after rescue PTCA in 3.0% versus 0.0% in primary PTCA patients. Clinical outcomes during hospital stay in terms of death rate (4.0% and 6.6%), reinfarction (6.0% and 3.9%), recurrent angina (16.0% and 11.8%), and repeat interventions were comparable, as was the first-year outcome. Failed PTCA was the most important predictor of a poor 1-year outcome; 28.0% died after failed PTCA versus 4.6% after successful PTCA (p < 0.001). In this retrospective analysis of 176 AMI patients, angiographic and clinical outcome, including a 1-year follow-up in patients who had rescue PTCA after failed thrombolysis, were of the same magnitude of patients in whom primary PTCA was performed. These findings suggest that in this subset the outcome of patients with rescue PTCA because of failed thrombolysis is good and is comparable with patients who underwent primary PTCA.

An Angiographic Study of Intracoronary Streptokinase versus Intravenous Tissue Plasminogen Activator After Failed Coronary Thrombolysis with Intravenous Streptokinase

Objective: The medical treatment of failed intravenous streptokinase in patients with acute transmural myocardial infarction using angiographic endpoints. Design: Prospective open angiographic comparison of intracoronary streptokinase with intravenous tissue plasminogen activator. Setting: Single center study in a tertiary institution. Subjects: Eighty-five patients with acute myocardial infarction within 4 hours after symptom onset. Treatment regimens: The subjects received 1.5 million U intravenous streptokinase. Coronary angiography within 48 hours (median 19 hours) showed infarct-related vessel patency in 65 patients (76%). In the catheterization laboratory the 20 patients (24%) with failed intravenous streptokinase received repeat thrombolysis immediately after angiography. The first 10 patients with failed intravenous streptokinase received intracoronary streptokinase at a dose of 4000 U/min in the occluded infarct-related artery for a maximum of 1 hour. The subsequent 10 pati ents received high-dose front-loaded intravenous tissue plasminogen activator (100 mg in 1 hour). Results: In none of the patients receiving repeat streptokinase was reperfusion obtained. In 6 of 10 (60%) of the patients receiving tissue plasminogen activator, reperfusion was seen within 60 minutes (p < 0.005 vs. intracoronary streptokinase). One patient (5%) died and two refused follow-up angiography. Seventeen (88%) patients underwent angiography 3 months later according to the protocol. Two patients showed a persistently reperfused infarct-related artery, three reoccluded, four spontaneously reperfused, and eight had a persistently occluded infarct-related artery. The left ventricular ejection fraction was slightly higher at 3 months, and there were no differences between the patients with open vessels (increase +7.7 +/- 5.8%) and those with persistently occluded vessels (increase +5.8 +/- 6.8%). Conclusions: Repeat thrombolysis after failed intravenous streptokinase ca n be achieved with front-loaded intravenous tissue plasminogen activator but not with intracoronary streptokinase. Although patient numbers are small and repeat thrombolysis was performed rather late, this study leads the way to affordable optimization of thrombolysis, which needs large-scale testing.

Saruplase in Myocardial Infarction

Saruplase is an unglucosylated single-chain recombinant urokinase-type plasminogen activator. Dose finding studies in patients with acute myocardial infarction indicated that a dose of 80 mg of saruplase, given as a bolus of 20 mg and iv infusion of 60 mg in one hour, led to excellent patency figures.Saruplase is most effective when combined with a bolus of 5000 IU heparin followed by an iv heparin infusion for at least 24 hours.When saruplase is compared to other thrombolytic agents (streptokinase, alteplase, urokinase), it becomes apparent that its profile is excellent. Early patency rates are at least comparable to alteplase. Further reocclusion rates of saruplase after one day are lower than those of streptokinase and alteplase. Patency rates 24-72 hours after start of medication are comparable between saruplase and urokinase.The large database in over 6000 patients shows that saruplase, in comparison to the other thrombolytic agents, is safe. Its bleeding complication rate is significantly lower than streptokinase, and a trend to lower in-hospital mortality is observed when compared to urokinase.Summarizing, when comparing to the presently available thrombolytic agents, saruplase is a fast acting, effective and safe thrombolytic agent.

Complete atrioventricular block complicating acute myocardial infarction in the thrombolytic era. SPRINT Study Group and the Israeli Thrombolytic Survey Group. Secondary Prevention Reinfarction Israeli Nifedipine Trial

OBJECTIVES

We assessed the incidence, associated clinical parameters and prognostic significance of complete atrioventricular block (CAVB) complicating acute myocardial infarction (AMI) in the thrombolytic era and compared them to data from the prethrombolytic era.

BACKGROUND

The introduction of new therapeutic modalities to treat AMI, aimed to enhance coronary reperfusion and to limit myocardial necrosis, was expected to decrease the incidence of CAVB and to improve prognosis. However, there are only limited data regarding the incidence and the prognosis of AMI patients with CAVB in the thrombolytic era.

METHODS

Data from 3,300 patients from the Israeli Thrombolytic Surveys (prospective, nationwide surveys of consecutive patients with AMI in all 25 coronary-care units in Israel in 1992 and 1996) were analyzed and compared with data from 5,788 patients included in the SPRINT (Secondary Prevention Reinfarction Israeli Nifedipine Trial) Registry (1981 to 1983).

RESULTS

During the 1990s, the incidence of CAVB was 3.7% compared with 5.3% in the 1980s, p = 0.0007. In the 1990s, mortality of patients with CAVB was significantly higher than in those without CAVB at 7 days (odds ratio [OR] = 4.05 95% CI [confidence interval] 2.34 to 6.82, 30 days OR = 3.98 [95% CI 2.44 to 6.43] and one-year hazard ratio [HR] = 2.36, [95% CI 1.68 to 3.30]) and similar in thrombolysis-treated and not-treated patients. Mortality of patients with CAVB has not changed significantly between the two periods; seven-day OR = 0.82 (95% CI 0.46 to 1.43); 30-day OR = 0.78 (95% CI 0.45 to 1.33) and one-year HR = 0.79 (95% CI 0.54 to 1.56), respectively, in the 1990s as compared to a decade earlier.

CONCLUSIONS

The incidence of CAVB complicating AMI is lower in the thrombolytic era than in the prethrombolytic era. Mortality among patients with CAVB is still high and has not declined within the last decade. The AMI patients who develop CAVB in the thrombolytic era have significantly worse prognosis than do patients without CAVB.

Intraarterial catheter-directed thrombolysis: urokinase versus tissue plasminogen activator

The purpose of this study was to evaluate the differences between tissue plasminogen activator (TPA) and urokinase (UK) in the management of ischemic limbs. A total of 58 limbs (24 in the TPA group and 34 in the UK group) in 53 patients were studied prospectively. The two groups were based on the surgeon's preference for lytic agent. The dose regimen for UK was 150,000 IU/hr over 1/2 to 2 hr followed by a continuous infusion of 50,000 IU/hr. TPA was given as a 5-mg bolus followed by 1 mg/hr. Both groups received heparin at a rate of 400 IU/hr through the side arm of the arterial sheath. There was no significant difference in efficacy between UK and TPA, but TPA acted faster and had a higher incidence of bleeding complications.

Thrombolysis in acute myocardial infarction: analysis of studies comparing accelerated t-PA and streptokinase

OBJECTIVES

To compare outcomes from accelerated alteplase (recombinant tissue plasminogen activator, t-PA) and streptokinase use in acute myocardial infarction.

METHODS

Review of available studies identified by Medline and other literature searches that met the criteria of being a prospective, randomised clinical trial enrolling over 1000 patients with acute myocardial infarction. The studies had to contain an intervention arm comprising accelerated infusion t-PA, or an intervention arm comprising streptokinase provided accelerated t-PA that was compared in the same trial. Interventions compared were streptokinase 1.5 million units given over one hour compared with accelerated t-PA infusion, with concomitant use of aspirin and heparin, and main outcome measure of 30 day mortality.

RESULTS

Four studies met prespecified criteria, these being the GUSTO I, GUSTO IIb Angioplasty Substudy, GUSTO III, and COBALT trials. There was a total study population of 64,387 patients of whom 20,251 received streptokinase, 19,474 received t-PA, with others receiving different treatment. Pooled data show that accelerated t-PA produces a marginal 30 day mortality advantage compared with streptokinase (6.6% v 7.3%, p = 0.02, Bonferroni adjusted p = 0.12, that is borderline significance, relative risk 0.918, 95% confidence interval 0.854 to 0.986). Any benefit is attributable entirely to patients recruited in the United States in the GUSTO I study. There is an increased incidence of stroke with t-PA.

CONCLUSIONS

The data do not consistently show a 30 day mortality benefit from using t-PA compared with streptokinase in acute myocardial infarction, but do show increased risk of stroke. Streptokinase can be considered the thrombolytic agent of choice.

Coronary microembolization--its role in acute coronary syndromes and interventions

The diagnosis coronary artery disease is classically based on patient's symptoms and morphology, as analyzed by angiography. The importance of risk factors for the development of coronary atherosclerosis and disturbance of coronary vasomotion is clearly established. However, microembolization of the coronary circulation has also to be taken into account. Microembolization may occur as a single or as multiple, repetitive events, and it may induce inflammatory responses. Spontaneous microembolization may occur, when the fibrous cap of an atheroma or fibroatheroma (Stary i.v. and Va) ruptures and the lipid pool with or without additional thrombus formation is washed out of the atheroma into the microcirculation. Such events with progressive thrombus formation are known as cyclic flow variations. Plaque rupture occurs more frequently than previously assumed, i.e. in 9% of patients without known heart disease suffering a traffic accident and in 22% of patients with hypertension and diabetes. Also, in patients dying from sudden death microembolization is frequently found. Patients with stable and unstable angina show not only signs of coronary plaque rupture and thrombus formation, but also microemboli and microinfarcts, the only difference between those with stable and unstable angina being the number of events. Appreciation of microembolization may help to better understand the pathogenesis of ischemic cardiomyopathy, diabetic cardiomyopathy and acute coronary syndromes, in particular in patients with normal coronary angiograms, but plaque rupture detected by intravascular ultrasound. Also, the benefit from glycoprotein IIb/IIIa receptor antagonist is better understood, when not only the prevention of thrombus formation in the epicardial atherosclerotic plaque, but also that of microemboli is taken into account. Microembolization also occurs during PTCA, inducing elevations of troponin T and I and elevations of the ST segment in the EKG. Elevated baseline coronary blood flow velocity, as a potential consequence of reactive hyperemia in myocardium surrounding areas of microembolization, is more frequent in patients with high frequency rotablation than in patients with stenting and in patients with PTCA. The hypothesis of iafrogenic microembolization during coronary interventions is now supported by the use of aspiration and filtration devices, where particles with a size of up to 700 microns have been retrieved. In the experiment, microembolization is characterized by perfusion-contraction mismatch, as the proportionate reduction of flow and function seen with an epicardial stenosis is lost and replaced by contractile dysfunction in the absence of reduced flow. The analysis of the coronary microcirculation, in addition to that of the morphology and function of epicardial coronary arteries, and in particular appreciation of the concept of microembolization will further improve the understanding of the pathophysiology and clinical symptoms of coronary artery disease.