[Thrombolytic therapy in acute myocardial infarction--update].
Explore the source record for details and available documents.
Humans↗
Biomedical subjects
D Zahger
Publications and source records attributed to D Zahger.
Clinical problem-solving. A broken heart.
Explore the source record for details and available documents.
Aged↗
Effect of smoking status on response to thrombolytic therapy.
Explore the source record for details and available documents.
Age Factors↗
Incomplete recanalization as an important determinant of Thrombolysis in Myocardial Infarction (TIMI) grade 2 flow after thrombolytic therapy for acute myocardial infarction. TEAM Investigators. Thrombolytic Trial of Eminase in Acute Myocardial Infarction.
The outcome of patients with Thrombolysis in Myocardial Infarction (TIMI) trial grade 2 flow is worse than that of patients with TIMI grade 3 flow after thrombolytic therapy for acute myocardial infarction. It is unclear whether TIMI grade 2 flow represents incomplete recanalization of the culprit lesion or poor distal runoff. The Thrombolytic Trial of Eminase (anistreplase) in Acute Myocardial Infarction (TEAM)-2 and TEAM-3 were randomized trials comparing anistreplase with streptokinase (TEAM-2, n = 370) or with alteplase (tissue plasminogen activator) (TEAM-3, n = 325). We compared the minimal luminal diameter of the culprit lesion in patients with TIMI grade 2 flow with that in patients with TIMI grade 3 flow both 90 minutes (TEAM-2) and 1 day (TEAM-3) after thrombolysis. Patients with TIMI grade 2 flow had a lower residual luminal diameter in the culprit lesion than patients with TIMI grade 3 flow (TEAM-2, 0.58 +/- 0.03 vs 0.79 +/- 0.02 mm, p = 0.0001; TEAM-3, 0.88 +/- 0.04 vs 1.17 +/- 0.03 mm, p = 0.0001, for patients with TIMI grades 2 and 3 flow). Residual percent stenosis was correspondingly higher in patients with TIMI grade 2 flow. At the early angiogram, 66% of patients with TIMI grade 2 flow, but only 35% of those with TIMI grade 3 flow, had a minimal luminal diameter of 0.6 mm (positive predictive value 87%, negative predictive value 35%). Incomplete recanalization of the culprit lesion may thus be an important determinant of TIMI grade 2 flow after thrombolysis. Whether more complete thrombolysis or rescue angioplasty improves outcome in these patients deserves evaluation.
Analysis of Variance↗
VCL, an antagonist of the platelet GP1b receptor, markedly inhibits platelet adhesion and intimal thickening after balloon injury in the rat.
BACKGROUND: Arterial injury is immediately followed by platelet adhesion at the site of injury, a process that requires the interaction of subendothelial von Willebrand factor with the platelet GP1b receptor. VCL, a recombinant von Willebrand factor GP1b binding domain, inhibits platelet binding to von Willebrand factor. The aim of this study was to determine whether VCL inhibits platelet adhesion at the site of arterial injury and affects neointimal thickening after injury in rats. METHODS AND RESULTS: Sprague-Dawley rats were randomized to receive VCL, 4 mg/kg bolus followed by a continuous infusion of 2 mg.kg-1.h-1 for 72 hours, or an identical volume of saline. Balloon injury of the femoral artery was performed 15 minutes after the initial bolus injection of VCL. Scanning electron microscopy performed 1 and 3 days after injury indicated that VCL-treated rats had > 80% reduction in the number of platelets adherent to the vessel wall at the site of injury compared with controls (P < .003). Histological examination at day 14 showed that, compared with controls, VCL-treated rats had a 60% reduction in the intima-media ratio (0.21 +/- 0.03 versus 0.53 +/- 0.06, P = .001) and a reduced luminal area stenosis (12 +/- 3% versus 38 +/- 10%, P = .04). At 28 days after injury, there was no rebound of neointimal thickening in VCL-treated rats (intima-media ratio, 0.19 +/- 0.04; luminal stenosis, 17 +/- 5%). The difference between VCL-treated rats and control rats persisted but was attenuated (intima-media ratio, 0.19 +/- 0.04 versus 0.28 +/- 0.1, P = .162; luminal stenosis, 17 +/- 5% versus 31 +/- 5%, P = .058) as neointimal thickening regressed in untreated rats. With the use of proliferating cell nuclear antigen immunohistochemistry on day 3, VCL had no effect on smooth muscle cell (SMC) proliferation. CONCLUSIONS: Antagonism of the platelet GP1b receptor by VCL profoundly decreased platelet deposition at the site of balloon injury in the rat femoral artery. This effect was associated with a persistent reduction in neointimal thickening. The lack of effect of VCL on SMC proliferation suggests that the decrease in neointimal thickening may have been mediated through inhibition of SMC migration and/or modulation of the extracellular matrix.
Angioplasty, Balloon↗
Absence of lethal reperfusion injury after 3 hours of reperfusion. A study in a single-canine-heart model of ischemia-reperfusion.
BACKGROUND: Whether reperfusion can cause necrosis of previously viable myocytes (lethal reperfusion injury) remains controversial. Numerous studies examined the ability of various agents to prevent or limit reperfusion injury, but the results were contradictory. In a single-canine-heart model of ischemia-reperfusion, we previously demonstrated that 5 minutes of reperfusion does not increase the transmural extent of necrosis. Since the 5-minute period of reperfusion is considered by some to be too short for the full manifestation of reperfusion injury, we reexamined the issue of lethal reperfusion injury using a modification of the single-heart model of ischemia-reperfusion that allowed extending the reperfusion period to 3 hours. METHODS AND RESULTS: In anesthetized, open-chest dogs, the distal half of the left anterior descending coronary artery (LAD) segment between the last diagonal branch and the apex was perfused via a shunt from the left carotid artery. The shunt was closed for periods of 90 to 180 minutes, depending on the ECG severity of ischemia, and reperfused for 3 hours. While the distal region was perfused from the carotid artery, the LAD was occluded proximal to the last diagonal branch for the same period of time as the distal region had been earlier. The time of occlusion was chosen such that the end of the occlusion period coincided with the end of the experiment. Thus, both regions of the LAD territory were subjected to identical periods of ischemia, but only the distal region was reperfused. At the end of the experiment, the boundary between the proximal (nonreperfused) and distal (reperfused) area was delineated by blue dye, and the heart was arrested, cut into slices 1 cm thick parallel to the LAD, and placed in triphenyltetrazolium chloride. The epicardial edges of necrosis in the reperfused and the nonreperfused regions were examined for any shift that might suggest a difference in the transmurality of necrosis. The areas of necrotic and viable myocardium were measured by planimetry within 1 cm on either side of the boundary. In all 14 dogs, the epicardial edges of necrosis ran as a single line across the boundary, and no shift was present. There was also no difference in the transmurality of necrosis between the reperfused and nonreperfused regions (64.9 +/- 20.7% versus 66.1 +/- 17.0% of left ventricular wall thickness, respectively, P = .32 by paired t test). CONCLUSIONS: In a single-canine-heart model of ischemia-reperfusion, there was no evidence of lethal reperfusion injury after 3 hours of reperfusion.
Animals↗
How do smokers differ from nonsmokers in their response to thrombolysis? (the TIMI-4 trial)
Smokers with acute myocardial infarction appear to have a better outcome after thrombolysis than do nonsmokers. To identify factors that could contribute to this curious finding, we analyzed data from the Thrombolysis in Myocardial Infarction (TIMI-4) trial, in which 382 patients with acute myocardial infarction were randomized to tissue plasminogen activator, anistreplase, or both. Coronary angiography was performed 90 minutes and 18 to 36 hours after randomization, a myocardial perfusion scan was performed at 18 to 36 hours and before discharge, and a radionuclide ventriculogram was obtained before discharge. Angiographic and clinical outcome variables were determined in current smokers, ex-smokers, and nonsmokers, and regression analysis was used to correct for differences in baseline characteristics. The in-hospital mortality of current smokers was lower than that of ex-smokers and nonsmokers: 2.3% versus 5.2% versus 7.0%, respectively (p = 0.04 by paired comparison, current vs nonsmokers). Ninety minutes after randomization, the incidence of TIMI grade 3 flow was significantly higher in smokers than in ex-smokers and nonsmokers (55% vs 43% and 45%, p = 0.02); this difference was no longer observed at the second angiogram, nor did smokers differ from nonsmokers with respect to residual stenosis, thrombus grade, infarct size, ejection fraction, or recurrent ischemia. Because a strong inverse relation exists between TIMI grade 3 flow at 90 minutes and mortality, our findings suggest that the lower mortality of current smokers after thrombolytic therapy may be related to a higher incidence of early, complete reperfusion.
Double-Blind Method↗
Thrombolytic Therapy for Acute Myocardial Infarction in Patients with Prior Coronary Bypass Surgery: Results from the Thrombolysis in Myocardial Infarction (TIMI) 4 Trial.
Little data exist on the value of intravenous thrombolysis for acute myocardial infarction in patients with previous coronary bypass surgery. The Thrombolysis In Myocardial Infarction (TIMI) 4 trial was a randomized study comparing tissue plasminogen activator, anistreplase, or a combination in patients with evolving myocardial infarction; patients with previous coronary bypass surgery were not excluded. Coronary angiography was performed 90 minutes and 18-36 hours after randomization, a myocardial perfusion scan was performed at 18-36 hours and predischarge, and a radionuclide ventriculogram was obtained predischarge. Angiographic and clinical outcome variables were determined in patients with and without a history of coronary bypass surgery. A total of 416 patients were randomized and 13 of them had previous bypass surgery; of these, 6 had an occluded vein graft as the infarct-related vessel. The incidence of TIMI grade 3 flow at 90 minutes was lower in patients with previous coronary surgery as compared with controls (42% vs. 49%), and overall patency was significantly lower (50% vs. 77%, p = 0.04). This trend persisted at 18-36 hours after randomization. Furthermore, patients with previous coronary surgery had more thrombus in their infarct-related arteries, especially with occlusion of a vein graft (83% vs. 32%, p = 0.04) and higher rates of recurrent ischemia (15% vs. 8%) and recurrent infarction (23% vs. 5%, p = 0.03) than controls. Thus, in patients with previous coronary bypass surgery intravenous thrombolysis yields results that are inferior to those achieved in patients without such a history and alternative methods of reperfusion should be considered.
Journal Article↗
Thrombolysis in the era of the randomized trials.
Thrombolytic therapy in acute myocardial infarction is of established value in recanalizing the occluded coronary artery, reducing infarct size, and decreasing mortality. Here, we review the extensive information provided by large clinical trials on agent and patient selection, timing of treatment, adjuvant therapies, and complications. Early treatment is of prime importance. Tissue plasminogen activator is slightly superior to streptokinase, especially in young patients treated early. Intravenous heparin should be used in conjunction with tissue plasminogen activator, although its role when streptokinase is used is less clear. Aspirin, beta-blockers, and converting enzyme inhibitors are of proven value as adjunctive therapies; nitrates and magnesium are not. Newer antithrombotic and antiplatelet agents (eg, hirudin and glycoprotein IIb/IIIa receptor antagonists) may further improve results.
Combined Modality Therapy↗
Early heart rate variability alterations after acute myocardial infarction.
In order to assess early changes in heart rate variability, we studied 81 patients with acute myocardial infarction during the initial 24 hours after thrombolytic therapy. The standard deviation of the mean heart rate and the low (0 to 0.05 Hz), mid (0.05 to 0.20 Hz), and high (0.20 to 0.35 Hz) frequency band power were evaluated with 24-hour ECG Holter recordings. We found diminished variance in the time domain and reduced power spectrum in the frequency domain compared with a group of 41 normal subjects (p < 0.01). Patients with anterior infarction had significantly (p < 0.01) higher heart rates and lower heart rate variability values than patients with inferior infarction. Reduction in heart rate variability occurred within the first 8 hours in patients with anterior infarction; a significant fall (p < 0.03) was especially noted in the high-frequency band after a decline in ST-segment elevation. Heart rate variability alterations in patients with inferior infarction were most evident in the final 8-hour interval. These findings may be viewed in terms of sympathovagal imbalance and may be related to clinical signs of intense autonomic nervous system activity that are observed early in the course of acute anterior and inferior myocardial infarction.
Aspirin↗
Very early appearance of Kaposi's sarcoma after cardiac transplantation in Sephardic Jews.
Explore the source record for details and available documents.
Africa, Northern↗
Delayed quinidine-induced diarrhea after five years of treatment.
Explore the source record for details and available documents.
Diarrhea↗
[New approaches in cardiogenic shock--thrombolysis, big balloons, small balloons].
Explore the source record for details and available documents.
Angioplasty, Balloon, Coronary↗
Limitations of the captopril test in the diagnosis of renovascular hypertension.
The captopril test has been suggested as a sensitive and specific noninvasive tool for the diagnosis of renovascular hypertension. We applied the test to 72 consecutive hypertensive patients in whom renal artery stenosis was suspected. The test was positive in seven cases (9.7%), of whom four were true positive and three false positive. The captopril test has value in screening for renovascular hypertension, but its limitations should be recognized. False positive results are not uncommon and false negative results have been reported under certain circumstances. Nevertheless, when properly applied to appropriate patients, the test can enhance the diagnosis of renal artery stenosis.
Adolescent↗
Partial resistance to anticoagulation after streptokinase treatment for acute myocardial infarction.
This study examines the response of 3 different groups of patients to anticoagulants: 50 patients previously treated with streptokinase for acute myocardial infarction (AMI) (group 1), 24 patients with AMI who had received anticoagulants without prior thrombolysis (group 2) and 11 subjects who received anticoagulants for noncoronary indications (group 3). No significant differences were detected between groups 2 and 3; therefore, they were combined for analysis. After streptokinase, patients required 37,755 +/- 1,516 (mean +/- standard error of the mean) U of heparin per day to achieve the desired activated partial thromboplastin time (APTT). The dosage was 30,294 +/- 1,089 U/day in patients without antecedent thrombolysis (p less than 0.001). Group 1 patients required 5 +/- 0.4 days until adequate anticoagulation was achieved, compared with 3 +/- 0.2 days in the control group (p = 0.01). Despite higher heparin requirements, group 1 patients had a lower APTT value than the other subjects (87 +/- 5 vs 101 +/- 6 seconds, p = 0.08). Group 1 patients required 5 +/- 0.3 days to reach anticoagulation with warfarin versus 4 +/- 0.2 days in groups 2 + 3 (p = 0.05). Comparison of groups 1 and 2 yielded similar, although smaller, differences. Patients treated with streptokinase for AMI seem to be partially resistant to anticoagulation, which may increase the risk of reocclusion.
Anticoagulants↗
Systemic embolization following thrombolytic therapy for acute myocardial infarction.
We describe a patient with acute inferior myocardial infarction who developed a "saddle" aortic embolus during streptokinase infusion. Three months previously, this patient had sustained an anterior infarction, and an apical aneurysm was found. This patient's embolus had most probably originated from a left ventricular mural thrombus that had been dislodged by streptokinase. As fibrinolytic treatment is gaining wide acceptance, physicians should be aware of this rare, but possible, complication.
Aged↗
[An outbreak of hepatitis B associated with acupuncture].
2 clusters of between 5 and 11 cases of hepatitis B virus infection were associated with acupuncture by a physician late in 1986. The source of the infection is believed to have been an Ethiopian immigrant, a known HBsAg carrier. While he was being operated on a nurse cut her finger on a scalpel blade. During the prodromal period of hepatitis which followed, she was treated by acupuncture. The acupuncture needles were supposedly sterilized by dry heat for 80 minutes at 200 degrees. However, there were apparently breaks in technique which were responsible for the spread of the infection to at least 4 other women, ranging in age from 26 to 80 years. We stress the need for strict enforcement of correct sterilization procedures whenever needles are used to pierce skin. This should be performed only by licensed practitioners of officially recognized occupations, some of which are not as yet covered by our national health regulations.
Acupuncture Therapy↗
Cholestatic liver injury after prolonged exposure to methyldopa.
We describe a 75-year-old patient who presented with severe cholestatic liver disease. He had been receiving methyldopa, 250 mg daily, for 6 years. An extensive evaluation failed to reveal extrahepatic obstruction or serologic evidence of viral hepatitis. A liver biopsy disclosed marked cholestasis, without hepatitis, and was compatible with a rare form of methyldopa-induced liver injury. Cessation of drug treatment was followed by a slow but complete recovery. Cholestasis is a rare manifestation of methyldopa hepatotoxicity. Although methyldopa-associated liver injury usually appears after about 4 weeks of treatment, a history of a much longer exposure does not exclude this entity.
Aged↗