Emergency coronary artery bypass surgery after intracoronary thrombolysis for evolving myocardial infarction.

Sixteen patients underwent emergency coronary artery bypass surgery immediately after intracoronary streptokinase infusion for acute evolving myocardial infarction. Of these, 11 patients had 70% residual stenosis in the recanalised vessel, and in five thrombolysis was unsuccessful. There were no hospital deaths. All the patients sustained myocardial necrosis, the peak activity of creatine phosphokinase correlating with the time to reperfusion. Chest tube drainage (mean 960 ml) was significantly higher than for control patients but did not correlate with the total dosage of streptokinase. No patients had further myocardial infarction or developed recurrent angina. Selected patients may benefit from coronary bypass surgery after intracoronary streptokinase infusion. If necessary this may be performed immediately with low mortality and morbidity.     

Emergency coronary artery bypass surgery after intracoronary thrombolysis for evolving myocardial infarction

Sixteen patients underwent emergency coronary artery bypass surgery immediately after intracoronary streptokinase infusion for acute evolving myocardial infarction. Of these, 11 patients had 70% residual stenosis in the recanalised vessel, and in five thrombolysis was unsuccessful. There were no hospital deaths. All the patients sustained myocardial necrosis, the peak activity of creatine phosphokinase correlating with the time to reperfusion. Chest tube drainage (mean 960 ml) was significantly higher than for control patients but did not correlate with the total dosage of streptokinase. No patients had further myocardial infarction or developed recurrent angina. Selected patients may benefit from coronary bypass surgery after intracoronary streptokinase infusion. If necessary this may be performed immediately with low mortality and morbidity.     

Acute coronary artery occlusion during percutaneous transluminal coronary angioplasty: reopening by intracoronary streptokinase before emergency coronary artery surgery to prevent myocardial infarction

Percutaneous transluminal coronary angioplasty (PTCA) was complicated by acute coronary artery occlusion associated with ST elevation and severe chest pain in three patients. Within 10 minutes, the occluded artery was reopened by an intracoronary (i.c.) infusion of streptokinase, resulting in the disappearance of chest pain and normalization of ST segments. To keep the artery patent, i.c. streptokinase had to be continued until emergency bypass surgery was performed. In two patients, no myocardial infarction occurred, as shown by a normal postoperative left ventricular angiogram. ECG and thallium-201 scintigram. In the other patient, who was admitted with an inferior infarction and underwent PTCA after i.c. lysis, no infarct extension was observed. These results show that i.c. streptokinase rapidly opens an acute coronary artery occlusion complicating PTCA, preventing myocardial infarction.     

Mortality in patients undergoing coronary artery bypass surgery after myocardial infarction

Data on 1,700 patients who underwent coronary artery bypass surgery without additional cardiovascular procedures at the Texas Heart Institute were analyzed, relating the interval between myocardial infarction and operation to early mortality (within 30 days after operation). Patients who underwent coronary artery bypass surgery after a recent infarction (within 2 months before operation) had a higher rate of early mortality (14.5 percent) than patients who had an old infarction (6.9 percent) or no previous infarction (4.1 percent). The interval between recent infarction and operation was most significant. Mortality in patients who underwent operation within the first 7 days after acute infarction (38.1 percent) was more than six times greater than in patients who were operated on 31 to 60 days after infarction (5.8 percent). Mortality of those operated on 8 to 30 days after infarction was 16.4 percent. Elective coronary artery bypass surgery after recent infarction is best accomplished after the first 30 days, when there is no increased risk to the patient. Emergency coronary artery bypass after complicated acute myocardial infarction may be a lifesaving procedure, but it is associated with increased early mortality and should be reserved for those whose condition has not responded to aggressive medical therapy.     

Thrombolytic therapy in acute myocardial infarction: Review of clinical trials

Intracoronary infusion of streptokinase is associated with recanalization rates of 60 to 90% immediately after the procedure. Mortality data in published trials are conflicting. In 125 registry patients who had paired contrast ventriculograms before streptokinase infusion and hospital discharge, improvement in ejection fraction correlated with incomplete coronary obstruction before angiography, the presence of collateral vessels to the infarct area and recanalization of complete obstruction. In assessing the risk/benefit ratio of intracoronary streptokinase infusion, the risks of angiography in the setting of acute myocardial infarction, reocclusion, bleeding and such secondary interventions as angioplasty or bypass surgery must be considered. Intravenous infusion of conventional doses of streptokinase was associated with improved survival in some trials in which therapy began within 12 hours after the onset of infarction. Immediate recanalization rates in patients who received large doses of intravenous streptokinase were lower than those associated with intracoronary streptokinase infusion. The risks and benefits of high-dose intravenous streptokinase administration must still be assessed.     

Intracoronary thrombolysis in acute myocardial infarction

Forty-seven patients with acute myocardial infarction (MI) underwent intracoronary infusion of Thrombolysin or streptokinase. In 41, a completely reoccluded artery was reopened. Patency was associated with appearance of arrhythmias, relief of pain, gradual return of the ST-segment to the baseline and appearance of abnormal Q waves. Creatine kinase (CK) and MB-CK enzyme levels peaked earlier. Serial thallium scintigrams showed reduction in defect size after reperfusion, and the ejection fraction was higher compared with control. Eighteen patients were recommended for coronary bypass surgery for recurrent pain or severe multivessel disease.     

Recognition of myocardial infarction after cardiac surgery and its relation to cardiopulmonary bypass

The incidence of operatively related acute myocardial infarction in patients undergoing coronary artery bypass surgery and open-heart surgery was determined and compared. Elevation of at least two enzymes, SGOT > 200, LDH > 400, and CPK > 800, was noted in patients with myocardial infarction (P < 0.05). The overall incidence of infarction was 17 per cent, and there was no significant difference in frequency of infarction in the two groups. Inferior myocardial infarction was the most common locus of damage. All patients developing myocardial infarction in the coronary bypass surgery group had evidence of generalized coronary artery disease. Infarction most frequently developed in patients requiring multiple vessel bypasses. Lesions of the left main coronary artery seem to be critical. The cardiopulmonary bypass pump time was 33 per cent longer in patients sustaining myocardial infarction, a statistically significant difference (P < 0.02). Age, sex, arrhythmias, congestive heart failure, serum cholesterol, or uric acid levels appeared not to be related to the development of postsurgical myocardial infarction in these cases. These data indicate that myocardial infarction is common both after coronary bypass surgery and open-heart surgery, and that the incidence rises with the more difficult and longer operations.     

Coronary artery thrombolysis in acute myocardial infarction

Coronary thrombolysis with streptokinase infusion can be achieved if performed during the first 4 hours of the onset of myocardial infarction. It has been a consistent finding that lysis of the thrombus can reestablish angiographically documented, antegrade coronary flow. Restoration of blood flow and preservation of ischemic myocardium can be achieved after coronary thrombolysis. Coronary artery bypass surgery or percutaneous transluminal coronary angioplasty may be necessary when significant obstructive coronary artery lesions due to atherosclerotic plaques remain after successful thrombolysis.     

Percutaneous transluminal coronary recanalization: Procedure,results, and acute complications

Percutaneous transluminal coronary recanalization, a new therapeutic procedure used in acute myocardial infarction, offers significant reduction in mortality, as well as more effective limitation of the zone of infarction than has been possible with other pharmacologic treatment employed in the past. The risk of coronary angiography during acute myocardial infarction was surprisingly low, as was the risk of hemorrhagic complications following the intracoronary administration of relatively low doses of thrombolytic substances such as streptokinase. Mechanical recanalization was possible in about one fifth of patients and successful in approximately half of all such attempts, but complications occurred in a small percentage of attempts at this step. Coronary artery spasm was excluded as a possible cause of occlusion in almost all cases. Selective intracoronary infusion of streptokinase produced the highest degree of myocardial reperfusion, and best results were achieved when therapy was initiated shortly after thrombotic occlusion occurred. Residual stenosis of more than 75% luminal diameter narrowing was present in approximately three fourths of cases after complete thrombolysis, and the majority of patients remained appropriate candidates for coronary bypass surgery or for percutaneous transluminal coronary angioplasty (Grüntzig procedure). Although complete analysis of the efficacy of selective recanalization was difficult because it was not possible to establish a suitable control group for purposes of comparison, the mortality of less than 1% in the present group of 232 patients within the first 6 hours following myocardial reperfusion provides an encouraging result.     

The management of patients with acute myocardial infarction after successful reperfusion with streptokinase

Intracoronary streptokinase administration has been an effective procedure for establishing reperfusion of an evolving myocardial infarction by lysing the thrombus that is usually responsible for the infarction. After reperfusion is accomplished, appropriate management of the patient must be planned to provide the best chance for assuring continued vessel patency, and appropriate management of the patient's residual coronary artery disease also must be considered. In selected patients, percutaneous transluminal coronary angioplasty of the residual coronary lesion has been performed successfully immediately following reperfusion with streptokinase. Early coronary artery bypass graft surgery has been performed with good results in other patients. The appropriate management of the patient with acute myocardial infarction is still evolving, and only with additional study and experience will the "best" approach in the management of these patients be defined.     

Intravenous streptokinase during acute myocardial infarction. A prospective open study

To evaluate the efficacy of intravenous streptokinase in acute myocardial infarction (AMI) 108 patients received a high-dose (1.5 million units), short-term infusion (60 minutes) within 6 hours after onset of symptoms, followed by anticoagulation. Before discharge a submaximal exercise test and a coronary arteriography were performed in 100 surviving patients. Sixty-seven patients had a patent infarct-related vessel. Clinical reocclusion occurred in 21 patients. Left ventricular function was slightly, but not significantly, better in patients with patent infarct-related vessels: ejection fraction 59.5 +/- 13% versus 57.4 +/- 13%. Additional procedures were performed in 20 patients: percutaneous transluminal coronary angioplasty (PTCA) in 8 and coronary artery bypass surgery (CABG) in 12. The results indicate that streptokinase applicated during a 6 hour-time window is a potent thrombolytic agent in acute myocardial infarction with limited effect on global left ventricular function. Pre-discharge evaluation is necessary to screen patients for residual ischemia.     

Intracoronary infusion of streptokinase in patients with acute myocardial infarction: Effects of reperfusion on left ventricular performance

Cardiac catheterization and coronary angiography were performed on hospital admission in 32 consecutive patients with acute myocardial infarction. Twenty-six patients had total occlusion of an infarct-related coronary artery and six had severe proximal stenosis with poor distal flow. In 18 of the 26 patients with total occlusion, intracoronary infusion of Streptokinase resulted in reperfusion of the distal coronary artery. Seventeen of these 18 patients had severe coronary arterial stenosis at the site of the previous total occlusion. Hemodynamic indexes of left ventricular performance and ejection fraction determined by gated cardiac blood pool imaging did not change immediately after reperfusion (p [probability]= not significant [NS]). The mean (± standard deviation) left ventricular ejection fraction increased significantly (p = 0.007) from admission (44 ± 15 percent) to hospital discharge (55 ± 7 percent) in patients evidencing reperfusion of the occluded coronary artery. It did not change (p = NS) in this time span in the patients with severe stenosis alone, in those with total occlusion not demonstrating reperfusion after administration of streptokinase or in an additional 10 control patients with acute myocardial infarction not evaluated with coronary angiography. These data suggest that (1) coronary arterial thrombus is frequent in acute myocardial infarction and can be lysed by intracoronary streptokinase; (2) reperfusion with intracoronary streptokinase in acute myocardial infarction results in improved left ventricular performance between admission and hospital discharge.     

Unstable angina and evolving myocardial infarction following coronary bypass surgery: pathogenesis and treatment with interventional catheterization

Effective therapy for patients with unstable angina or evolving myocardial infarction following coronary bypass surgery requires accurate delineation of the pathoanatomy and prompt intervention. We therefore performed cardiac catheterization in 10 consecutive patients: four with acute myocardial infarction and six with refractory unstable angina (NYHA class IV). All patients with acute myocardial infarction were found to have completely thrombosed vein grafts supplying totally occluded native coronary arteries. In three patients with evolving myocardial infarction occurring within 4 weeks of coronary bypass surgery, graft thrombosis was caused by venous valves in two patients and a suboptimal anastomosis in a third. The fourth patient sustained a myocardial infarction 7 years after coronary bypass surgery with atherosclerotic plaque rupture causing vein graft thrombosis. Therapy with intragraft streptokinase resulted in complete clearing of thrombus, pain relief, and control of injury current in all four patients. Rest angina with concomitant ST and T wave changes occurred in six patients. In two patients symptoms occurred early (within 6 months), whereas angina developed 4 to 10 years after coronary bypass graft surgery in four patients. In the two patients with early recurrence of symptoms suboptimal anastomosis was found in one, while the other patient had a venous valve in the vein graft in conjunction with a stenosis in the native coronary artery. In three of four patients with late recurrence of angina, symptoms developed as a result of atherosclerotic stenosis in their vein grafts; in the fourth patient an occluded graft was found to supply a stenosed native coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intravenous short-term infusion of streptokinase in acute myocardial infarction

Clinically encouraging results can be obtained with an intravenous high dosage, short-term infusion of streptokinase in patients with evolving myocardial infarction. The feasibility and efficacy of the systemic approach of streptokinase therapy is discussed in this report and includes topics such as recanalization success rate, restoration of coronary blood flow, residual coronary artery lesions, salvage of jeopardized myocardium, time limits of effective reperfusion, transluminal angioplasty, coronary bypass surgery, and mortality. The value of high dosage intravenous short-term streptokinase infusion needs to be assessed with properly designed clinical trials.     

Systemic versus intracoronary streptokinase infusion in the treatment of acute myocardial infarction

Clinically encouraging results can be obtained with an intravenous high dose short-time infusion of streptokinase in patients with evolving myocardial infarction. The feasibility and efficacy of the intracoronary and the systemic approach of streptokinase therapy in acute myocardial infarction are discussed in this report and include topics such as infarct artery recanalization success rate, coronary thrombus lysis time, benefit for patients with subtotal coronary occlusion, reocclusion rate, the necessity of additional surgical interventions, salvage of ischemic myocardium and side effects. The value of high dose intravenous short-time streptokinase infusion needs to be assessed with properly designed clinical trials against the background afforded by the results observed with direct intracoronary streptokinase infusion.     

Coronary perfusion during acute myocardial infarction with a combined therapy of coronary angioplasty and high-dose intravenous streptokinase

Two hundred and sixteen patients with acute myocardial infarction were treated with immediate infusion of high-dose (1.5 million units) intravenous streptokinase followed by emergency coronary angioplasty. The infarct lesion was crossed and dilated in 99% and persistent coronary perfusion after the procedure was achieved in 90% (including 3% with significant residual stenosis). Total in-hospital mortality was 12%. Multivariable analysis showed a higher hospital mortality with cardiogenic shock (41% vs 5% without shock), older age, lower left ventricular ejection fraction, and female sex. Final patency of the infarct-related vessel was determined by follow-up in-hospital cardiac catheterization. Coronary reocclusion occurred in 11% (symptomatic in 7%, treated with emergency angioplasty or bypass surgery; silent in 4%, treated medically). Of the surviving patients with successful initial establishment of infarct vessel patency, 94% were discharged from the hospital with an open infarct artery or a bypass graft to the infarct vessel. There was significant improvement in both ejection fraction (44% to 49%; p less than .0001) and regional wall motion in the infarct zone (-3.0 SD to -2.4 SD; p less than .0001) among patients with persistent coronary perfusion and insignificant residual stenosis at the time of the follow-up cardiac catheterization. Thus, a treatment strategy for acute myocardial infarction that includes immediate administration of streptokinase followed by emergency coronary angioplasty, and coronary bypass surgery when necessary, results in a high rate of early and sustained patency of the infarct-related vessel.     

Thrombolysis in an aortocoronary saphenous vein graft

Selective intracoronary infusion of streptokinase during the acute phase of myocar-dial infarction may reduce myocardial necrosis. Thrombolytic therapy of acute myocardial infarction has been primarily applied to the native coronary circulation. We are reporting successful thrombolysis in an aortocoronary saphenous vein graft 39 months after bypass surgery. Thrombosis may have developed as a complication of catheterization, and streptokinase may also prove useful in the reversal of thrombosis in this setting.     

Intracoronary streptokinase thrombolytic recanalization and subsequent surgical bypass of remaining atherosclerotic stenosis in acute myocardial infarction: Complementary combined approach effecting reduced infarct size,preventing reinfarction,and improving left ventricular function

In 48 patients with acute myocardial infarction (AMI) the acutely thrombus-occluded coronary artery was successfully recanalized nonsurgically via catheter with intracoronary streptokinase (SK) infusion after a mean occlusion time of 3.1 ± 1.6 hours. In all cases residual high-grade fixed atherosclerotic stenosis remained after percutaneous transluminal coronary recanalization (PTCR). Subsequent aortocoronary bypass surgery (ACBS) circumventing the stenotic coronary artery was performed during the acute stage of myocardial infarction (within 10 days of AMI onset) in 34 patients and electively (longer than 10 days after AMI onset) in 14 patients. No patient died from early PTCR or from ACBS intervention. There were two late post-ACBS arrhythmogenic deaths, two patients suffered nonfatal reinfarction post ACBS several months after hospital discharge, only two had occasional post-ACBS angina pectoris, and one patient had post-ACBS mild heart failure. The remaining 41 post-ACBS patients were completely asymptomatic throughout long-term follow-up evaluation. In the left ventricular (LV) segment supplied by the initially occluded coronary artery, which was recanalized early by means of SK therapy and subsequently grafted, wall motion improved significantly from the acute to the postoperative stage in patients who underwent early surgery (from 13.6% ± 1.9% to 40.3% ± 2.7%, p < 0.001) and in the electively operated group (from 18.0% ± 7.1% to 48.2% ± 6.3%, p < 0.001). Ischemic wall motion was improved irrespective of whether or not the bypass graft circumventing the residual stenosis of the infarct vessel remained patent. Wall motion of nonischemic segments remained essentially unchanged. In the patients who underwent surgery in the early stage, the closure rate of the bypass graft to the infarct-related vessel was 17%, and in the electively operated group no graft was found to be occluded. In conclusion, coronary artery recanalization, achieved by means of early SK-PTCR therapy with subsequent ACBS, can be performed safely in patients with AMI, and the result will be marked improvement in LV segmental wall motion and global function, diminished reinfarction rate, and reduced incidence of angina pectoris, all benefits that are consistently maintained during long-term evaluation.     

Coronary angiographic morphology in myocardial infarction: a link between the pathogenesis of unstable angina and myocardial infarction

It has previously been shown that analysis of coronary morphology can separate unstable from stable angina. An eccentric stenosis with a narrow neck or irregular borders, or both, is very common in patients who present with acute unstable angina, whereas it is rare in patients with stable angina. To extend these observations to myocardial infarction, the coronary morphology of 41 patients with acute or recent infarction and nontotally occluded infarct vessels was studied. For all patients, 27 (66%) of 41 infarct vessels contained this eccentric narrowing, whereas only 2 (11%) of 18 noninfarct vessels with narrowing of 50 to less than 100% had this lesion (p less than 0.001). In addition, a separate group of patients with acute myocardial infarction who underwent intracoronary streptokinase infusion were also analyzed in similar fashion. Fourteen (61%) of 23 infarct vessels contained this lesion after streptokinase infusion compared with 1 (9%) of 11 noninfarct vessels with narrowing of 50 to less than 100% (p less than 0.01). Therefore, an eccentric coronary stenosis with a narrow neck or irregular borders, or both, is the most common morphologic feature on angiography in both acute and recent infarction as well as unstable angina. This lesion probably represents either a disrupted atherosclerotic plaque or a partially occlusive or lysed thrombus, or both. The predominance of this morphology in both unstable angina and acute infarction suggests a possible link between these two conditions. Unstable angina and myocardial infarction may form a continuous spectrum with the clinical outcome dependent on the subsequent change in coronary supply relative to myocardial demand.     

Percutaneous transluminal coronary angioplasty: an update

Rapid and progressive improvement in techniques and decreased morbidity and mortality rates have taken place since the introduction in 1977 of PTCA for the treatment of coronary artery disease. PTCA is now performed worldwide. Originally used for proximal single-vessel disease, which is still the ideal lesion, criteria for PTCA have expanded to include multiple stenotic lesions in one or more vessels, distally located obstructive lesions, patients with prior coronary artery bypass surgery, and patients with acute myocardial infarction where PTCA is performed in combination with streptokinase lysis of an obstructive thrombus.