Recent advances using streptokinase for acute coronary thrombosis

Most important in comparison to earlier European trials, streptokinase (STK) is administered now at the earliest time possible after acute coronary thrombosis. In this series, STK was started 2.5 (+/- 1.5) h after onset of chest pain, with reperfusion achieved approximately 1 h later in 6 (55%) of 11 patients treated. Posttreatment angiograms will not be required to identify thrombolysis if noninvasive indicators will provide this information correctly. Early creatine kinase enzyme peaking 8 to 15 h after chest pain appears to be the most accurate marker available. Among untreated and unsuccessfully treated patients, creatine kinase peaking usually occurs 18-36 h after chest pain. A large intravenous STK loading dose of 1,500,000 IU produces a plasma concentration of approximately 500 IU/ml, equal to that concentration employed originally by intracoronary infusions. Such large doses have been employed in 60 patients thus far, without an unusual incidence or severity of hemorrhages. High dose, ultrashort-term treatment for only 1 h is being investigated now. Systemic STK penetrates most "blind coronary pouches" and gains access to acute thrombi, as identified by radiocontrast material washout during angiography in patients with severe coronary occlusions. Streptokinase exerts a significant anticoagulant effect, not previous considered, which may be beneficial in the prevention of new clot formation and the rapid dissolution of acute coronary thrombi.     

Acute anterior myocardial infarction: streptokinase prevents ventricular thrombosis independently of its effect on infarct size

Left ventricular thrombosis (LVT) is a frequent complication after acute anterior myocardial infarction (AMI). The purpose of this study is to evaluate whether streptokinase (SK) therapy prevents LVT, and whether this effect is due to the preservation of left ventricular function or to the fibrinolytic action of the drug. Sixty-five patients who underwent a left ventricular angiography within 2 months after a first AMI were studied. Twenty-eight patients (SK group) received SK 1,500,000 U i.v. administered over 60 min within 6 h from the onset of symptoms. A lower incidence of LVT was found in the SK group (p = 0.0003). We divided patients into two classes according to the value of akinetic-dyskinetic area (AD): the first group with a lower value of AD, the second group with a higher value of AD. In both groups, a reduced incidence of LVT was associated with SK therapy (p = 0.014, p = 0.015, respectively). Early infusion of SK during AMI seems to prevent the development of LVT, with an effect partly independent from its action on infarct size for small to large myocardial infarction.     

Multiple coronary thromboses in previously normal coronary arteries treated with streptokinase

A patient is presented with normal coronary arteries in whom total occlusions in three branches of two epicardial coronary arteries developed in association with chest pain and electrocardiographic evidence of transmural ischemia. A combination treatment strategy addressing both coronary vasoconstriction and thrombosis is illustrated.     

Multiple coronary thrombosis in a patient with thrombocytosis

A 59-year-old woman was admitted with acute inferior myocardial infarction. Cardiac catheterization revealed total occlusion in the right coronary artery and thrombus-like filling defect in the left anterior descending coronary artery. With simultaneous intracoronary urokinase infusion to the right and left coronary arteries, the right coronary artery became patent and the thrombus in the left anterior descending coronary artery was released to the distal coronary artery. Thrombocytosis was disclosed by laboratory examination. The relationship between myocardial infarction and thrombocytosis is discussed.     

Acute myocardial infarction: intracoronary application of nitroglycerin and streptokinase.

In five patients with acute myocardial infarction, the effects of both intracoronary nitroglycerin (NTG) and subsequent intracoronary streptokinase application were evaluated. In addition, transluminal recanalization was performed in one of these patients. Injection of NTG into the infarct-related coronary artery resulted in improved distal filling of the subtotally occluded left circumflex artery in one patient, and in transient patency of the completely occluded right coronary artery in a second patient. In a third patient patency of the totally occluded left anterior descending artery (LAD) was achieved by transluminal recanalization with a guide wire. In a forth patient with occulsion of the LAD, there was no response to intracoronary NTG and mechanical recanalization was not attempted. Subsequent intracoronary infusion of streptokinase (1,000--2,000 U/min for 15--60 min) resulted in a further and long-term reduction of narrowing at the site of acute occlusion in patients I-III and in opening of the completely occluded LAD in patient IV. Improvement of lumen was paralleled by alleviation of symptoms. In a fifth patient, in whom the LAD was subtotally occluded, the degree of coronary obstruction could not be changed by intracoronary application of NTG or by lysis. In this patient, symptoms and ECG changes improved with reduction of pathologically elevated blood pressure values. The findings suggest that myocardial infarction had been caused by thrombotic occulsion in four patients, and that spasm of the infarct vessel could have been an additional factor in two of these patients. In the fifth patient, an increase of afterload in the presence of a subtotal lesion might have caused the critical imbalance between oxgen supply and demand, resulting in cell death.     

Intracoronary streptokinase therapy in the coronary care unit for acute myocardial infarction

Intracoronary streptokinase was offered and preliminary coronary angiography performed in 14 patients who were seen with the clinical diagnosis of acute myocardial infarction within 4 h of onset of symptoms. The procedure was performed in the Coronary Care Unit (CCU) of St. Peter's Medical Center with the use of a portable C-arm fluoroscope. Angiography was recorded on video tape. Service was provided by an "on-call" team consisting of two physicians, a CCU nurse, and a radiology technician, on a 24-h service basis. Adequate visualization of coronary anatomy was obtained in all patients. Patency of occluded vessels was achieved in 10 of 11 patients who received intracoronary streptokinase. The initial streptokinase bolus was administered at a mean interval of 4.1 h from onset of symptoms. It is concluded that speedy and effective coronary thrombolytic therapy can be provided in the CCU on a 24-h service basis by an on-call team. The use of CCU for this purpose will make this therapy widely available across the country, without the need for Cardiac Catheterization Laboratory.     

Intravenous versus intracoronary streptokinase for acute transmural myocardial infarction

In order to compare the thrombolytic efficacy of selective versus systemic administration of streptokinase, we gave this drug by either the intracoronary or intravenous routes to 25 patients during the first 6 hours of acute myocardial infarction. All patients had total occlusion of the infarct-related vessel, unresponsive to intracoronary nitroglycerin. Twelve patients received intravenous streptokinase and 13 received intracoronary administration of the drug. Angiograms were taken prior to and during streptokinase administration. Reopening was achieved in 11 of 13 intracoronary patients and 8 of 12 intravenous patients (P = Ns). Time to reopening was longer (54 minutes) in the intravenous patients than in the intracoronary patients (26 minutes) (P < 0.05). In this study, intravenous streptokinase reopened infarct-related vessels nearly as often as intracoronary streptokinase, but it took longer. Given the limited access and time to prepare for intracoronary infusion and the ease of intravenous administration, further study of intravenous streptokinase is justified.     

重组链激酶对犬冠状动脉栓塞的作用

本研究用２６只犬，分成５组分别为：生理盐水（ＮＳ）对照组、重组链激酶（ｒ－ＳＫ）１５０００ＩＵ／ｋｇ组、ｒ－ＳＫ３００００ＵＩ／ｋｇ组、ｒ－ＳＫ６００００ＵＩ／ｋｇ组及阳性对照链激酶（ＳＫ）３００００ＵＩ／ｋｇ组，以观察ｒ－ＳＫ的溶栓作用。在犬冠状动脉左前降支分支插管导入血栓后，心电图ＳＴ段抬高，心率明显减慢，冠状动脉造影见冠状动脉断流。用ｒ－ＳＫ后，栓塞引起的ＳＴ段抬高缓解，但心率无明显变化。冠状动脉造影的结果表明，随着ｒ－ＳＫ的剂量升高栓塞溶解的犬数增加。血液生化指标显示ｒ－ＳＫ对凝血时间和凝血酶原时间无影响，延长优球蛋白溶解时间，但降低纤溶酶原含量，增加Ｄ二聚体的含量。与ＮＳ组比较，ｒ－ＳＫ组心肌梗死面积明显减小。本研究证明静脉注射ｒ－ＳＫ能溶解犬冠状动脉栓塞。     

Selective intracoronary thrombolysis in the coronary care unit without cineangiography

Selective coronary artery visualization was performed in theCCU by means of a moveable fluoroscopy device in 96 patientswith suspected myocardial infarction within 6 hours after onsetof symptoms. Intracoronary streptokinase (SK) was administeredin a total dosage of 200 000 to 400 000 U within 30–60min to 69 patients with complete (N=57) or subtotal obstruction(N=12) of the infarct-related vessel. Recanalization was achievedin 39 of the 57 patients (68%) with initially complete occlusion.Threeof the 39 successfully treated patients died (7.7%) versus 8of 33 subjects (24%) with persistent complete obstruction (chi-square3.21, not significant). Selective cineangiography subsequentlyperformed in 8 patients and postmortem examination of 12 subjectswho had died, showed that all haemodynamically significant lesionshad been recognized by the examination in the CCU with one exception. It is concluded that intracoronary thrombolyis performed inthe CCU, by means of a standard mobile fluoroscopy equipmentis effective, safe, inexpensive and may be started virtuallywithout delay after admission.     

Coronary spasm producing coronary thrombosis in a patient with acute myocardial infarction

A 62-year-old man had an acute myocardial infarction with successful thrombolysis. Coronary spasm was documented in the following angiographic study. This case demonstrated that coronary spasm is implicated in the pathogenesis of coronary thrombosis and subsequent myocardial infarction.     

自发性冠状动脉夹层并血栓形成致急性心肌梗死2例

急性心肌梗死(AMI)是心内科的常见急症,其病死率和致残率较高。自发性冠状动脉夹层(SCAD)可因假腔压迫及合并血栓形成导致冠状动脉闭塞,是AMI的罕见病因之一。本文报告2例SCAD并血栓形成致AMI,并行冠状     

Preventive effects of batroxobin on experimental canine coronary thrombosis

The thrombolytic effects of urokinase (UK) and preventive effects of batroxobin, heparin, and aspirin on the recurrence of thrombosis in the coronary artery were studied in 118 anesthetized dogs with severe endothelial denudation and luminal stenosis of the coronary artery. Occlusive thrombi developed in 68 (58%) preparations (dogs), accompanied by a decrease of coronary blood flow and pressure, an electrocardiographic ST elevation, and epicardial cyanosis. An intravenous infusion of 20,000 IU/kg of UK reopened the occluded coronary artery in all 32 preparations with 1-h-old thrombi, in 6 (86%) of 7 preparations with 2-h-old thrombi, and in 5 (83%) of 6 preparations with 3-h-old thrombi. However, recanalization was not observed in preparations with thrombi more than 4-h-old. Occlusion recurred within 6 h after recanalization in 2 (18%) of 18 preparations pretreated with batroxobin (1-2 BU/kg) (p> .005 vs. control UK group), in 1 (14%) of 7 preparations administered a continuous infusion of 30 U/kg per h of heparin (p > .05 vs. control UK group), in 4 (57%) of 7 preparations pretreated with 2 mg/kg of aspirin, and in 7 (64%) of 11 preparations not pretreated (control UK group). Complete prevention was observed only in the group administered 2 BU/kg of batroxobin. Histologically, these thrombi closely simulated clinical arterial thrombi. Myocardial hemorrhage and contraction band necrosis were observed in the reperfused hearts. In conclusion, experimental canine coronary thrombi more than 4-h-old were resistant to thrombolytic therapy, and batroxobin and heparin were effective in the prevention of coronary reocclusion.     

Traumatic thrombosis of the left main coronary artery and myocardial infarction caused by blunt chest trauma

We report the case of a 38-year-old man who, after a blunt chest trauma, developed an acute transmural myocardial infarction. Coronary arteriography revealed a thrombus in the left main artery, occlusion of the distal left anterior descending artery, and a diagonal branch caused by emboli.     

Streptokinase thrombolysis in experimental coronary artery thrombosis: pattern of reflow and effect of a stenosis

We studied recanalization of an obstructed left circumflex coronary artery by streptokinase in open-chest anesthetized dogs. Thrombotic occlusion was induced by a 100 μA anodal current selectively delivered to the intimal surface of the vessel. Intracoronary streptokinase (50,000 U) or saline was infused over a 50-min period beginning at either 30 min or 90 min after occlusion. Continous recordings were made of antegrade circumflex flow and regional myocardial function, which was quantitated using sonomicrometer crystals in the regions of the left anterior descending and circumflex coronary arteries. In some experiments a fixed stenosis, having no effect on mean circumflex coronary artery blood flow, was placed at the site of subsequent thrombus formation. The presence of a stenosis decreased the weight of occlusive thrombi obtained from nonreperfused saline controls by 40% and increased the proportion of animals successfully reperfused by streptokinase from 13 to 76%. Streptokinase reduced thrombus mass by 44% in animals recanalized in the presence of the stenosis. On the average, reflow was established after 26 min of streptokinase infusion, was less in magnitude than pre-occlusion flow, and was unstable and intermittent, being marked by frequent reocclusions. Initiating treatment at 30 min or 90 min post-occlusion did not influence characteristics of the reflow. Return of myocardial contractility in the ischemic bed was not detected during the immediate reperfusion period in the majority of these experiments.     

Acute myocardial infarction after simultaneous thrombosis in normal right and left coronary arteries

A 32-year-old male patient with clinical and electrocardiographic evidence of acute myocardial infarction underwent coronary angiographic study. We observed nonocclusive thrombosis simultaneously in right and left anterior descending coronary arteries, without confirmation of spasm or obstructive artery disease in other coronary branches. Documentation of coronary thrombosis in more than one artery is rare, and its pathophysiology is still unknown. With the advent of thrombolytic therapy and immediate coronary angiographic studies in patients with evolving myocardial infarction, it has been possible to confirm the presence of thrombus and the type of coronary disease. In this case, we observed total lysis of both thrombi and the final aspect of "normal" angiographically reperfused coronary arteries.     

Acute myocardial infarction and large coronary thrombosis in a patient with COVID-19

This is a case report of a 60-year-old male, without any cardiovascular risk factor and no cardiac history admitted to hospital with a diagnosis of interstitial pneumonia caused by coronavirus disease 2019 (COVID-19). After 7 days, the blood tests showed a significant rise of inflammatory and procoagulant markers, along with a relevant elevation of high-sensitivity Troponin I. Electrocardiogram and transthoracic echocardiogram (TTE) were consistent with a diagnosis of infero-posterolateral acute myocardial infarction and the patient was transferred to the isolated Cath Lab for primary percutaneous coronary intervention (PCI). The angiography showed an acute massive thrombosis of a dominant right coronary artery without clear evidence of atherosclerosis. Despite the optimal pharmacological therapies and different PCI techniques, the final TIMI flow was 0/1 and after 3 hr the clinical condition evolved in cardiac arrest for pulseless electric activity. Acute coronary syndrome–ST-elevation myocardial infarction is a relevant complication of COVID-19. Due to high levels of proinflammatory mediators, diffuse coronary thrombosis could occur even in patients without cardiac history or comorbidities. This clinical case suggests that coronary thrombosis in COVID-19 patients may be unresponsive to optimal pharmacological (GP IIb–IIIa infusion) and mechanical treatment (PCI).     

Coronary artery spasm culminating in thrombosis following ergonovine stimulation

A 53-yr-old active man with angina but no angiographically significant obstructive coronary artery disease developed refractory spasm following ergonovine provocation. This resulted in thrombus formation and myocardial infarction. As such, this is the first case in which thrombosis developed at the site of intense coronary artery spasm induced by ergonovine, all of which were documented angiographically. Despite the notable safety of this test, this case re-emphasizes the potential of ergonovine to produce intractable myocardial ischemia and infarction.     

Recurrent coronary artery thrombosis after anomalous right coronary artery re‐implantation to the aorta

Anomalous origin of the right coronary artery (RCA) from the pulmonary artery is a rare entity. The current recommendation is corrective operation even in asymptomatic patients when this cardiac malformation is found. We report a case of a 21‐year‐old male who initially presented with ST elevations. After surgical repair with re‐implantation of the RCA to the aorta, he was found to have an acute thrombus in his left circumflex and several months later developed a thrombus in the proximal left anterior descending artery. We propose that the change from a hyperkinetic high flow state to a slow flow state in the setting of inadequate coronary flow reserve and endothelial function predisposed our patient to thrombus formation in the persistently dilated coronary arteries. It is expected that restoration of normal flow pattern in all coronary arteries will result in normalization of perfusion, decrease in feeding artery size, and return of endothelial function. Because this anomaly is rare, limited information exists on the effects of the procedure on myocardial perfusion. These findings raise the question of whether re‐implantation of the anomalous artery is truly the superior approach. © 2013 Wiley Periodicals, Inc.     

Echocardiography and coronary artery disease

Echocardiography is playing an increasingly important role in the management of patients with coronary artery disease. With the addition of new digital technology and new technological advances, such as multiplane transesophageal echocardiography and intravascular ultrasound, there is every expectation that this use of cardiac ultrasound will grow even more rapidly in the near future.