Clomethiazole (Zendra) in acute ischemic stroke: basic pharmacology and biochemistry and clinical efficacy

This review discusses the efficacy of clomethiazole (CMZ) in models of global and focal ischemia. The fact that neuroprotection is demonstrable by using histological, biochemical, and functional measures is emphasised. The importance of the neuroprotection observed when the drug is given after the ischemic insult and at doses that are safely tolerated by humans is discussed, with reference to requirements necessary for an experimental neuroprotective agent to be considered as a therapeutic drug for stroke. The biochemical pharmacology of CMZ is reviewed and also evaluated with reference to the possible mechanism(s) by which CMZ exerts its neuroprotective action. Finally, the clinical evidence that CMZ protects against the neurological consequences of a major stroke is outlined.     

Intravenous thrombolysis with recombinant tissue plasminogen activator for acute hemispheric stroke. The European Cooperative Acute Stroke Study (ECASS)

OBJECTIVE: To evaluate the efficacy and safety of intravenous thrombolysis using recombinant tissue plasminogen activator (rt-PA) in patients with acute ischemic stroke. DESIGN: Randomized, prospective, multicenter, double-blind, placebo-controlled clinical trial. SETTING: A total of 75 hospitals in 14 European countries. PATIENTS: A total of 620 patients with acute ischemic hemispheric stroke and moderate to severe neurologic deficit and without major early infarct signs on initial computed tomography (CT). INTERVENTION: Patients were randomized to treatment with 1.1 mg per kilogram of body weight of rt-PA (alteplase) or placebo within 6 hours from the onset of symptoms. OUTCOME MEASURES: Primary end points included Barthel Index (BI) and modified Rankin Scale (RS) at 90 days. Secondary end points included combined BI and RS, Scandinavian Stroke Scale (SSS) at 90 days, and 30-day mortality. Tertiary end points included early neurologic recovery (SSS) and duration of in-hospital stay. Safety parameters included mortality and incidence of intracranial or extracranial hemorrhage. RESULTS: The distribution of demographic variables was similar among patients in the rt-PA and placebo treatment arms in both the intention-to-treat (ITT) analysis and the explanatory analysis for the target population (TP). A total of 109 patients (17.4%) were included in the trial despite major protocol violations but excluded from the TP. There was no difference in the primary end points in the ITT analysis, while the TP analysis revealed a significant difference in the RS in favor of rt-PA-treated patients (P = .035). Of the secondary end points, the combined BI and RS showed a difference in favor of rt-PA-treated patients in both analyses (P < .001). Neurologic recovery at 90 days was significantly better for rt-PA-treated patients in the TP (P = .03). The speed of neurologic recovery assessed by the SSS was significantly better up to 7 days in the ITT analysis and up to 30 days for the TP in the rt-PA treatment arm. In-hospital stay was significantly shorter in the rt-PA treatment arm in both analyses. There were no statistically significant differences in the mortality rate at 30 days or in the overall incidence of intracerebral hemorrhages among the rt-PA and placebo treatment arms in either analysis. However, the occurrence of large parenchymal hemorrhages was significantly more frequent in the rt-PA-treated patients. CONCLUSIONS: Intravenous thrombolysis in acute ischemic stroke is effective in improving some functional measures and neurologic outcome in a defined subgroup of stroke patients with moderate to severe neurologic deficit and without extended infarct signs on the initial CT scan. However, the identification of this subgroup is difficult and depends on recognition of early major CT signs of early infarction. Therefore, since treating ineligible patients is associated with an unacceptable increase of hemorrhagic complications and death, intravenous thrombolysis cannot currently be recommended for use in an unselected population of acute ischemic stroke patients.     

Completion rates and feasibility of outcome measures: experience in a multicenter clinical trial of systemic hypothermia for severe head injury

The National Acute Brain Injury Study: Hypothermia (NABIS:H) is an ongoing multicenter trial of systemic hypothermia for the treatment of severe head injury. Follow-up rates for the study's 3-and 6-month outcome assessments have been maintained at high levels by establishing close contact with family members, by reimbursing cost of travel, and by sending examiners to the subject's location whenever necessary. Two years into the study, global disability data (e.g., Glasgow Outcome Scale) have been obtained on 86% of patients due for 3-month assessment (n = 131) and for all subjects due at 6 months (n = 100). Over half of the patients have completed neuropsychological testing with high reliability ratings. These preliminary findings suggest that the procedures used to document data quality and increase follow-up and completion rates are being successful.     

Acute phase proteins: alpha-1-acid glycoprotein (AGP) and alpha-1 antichymotrypsin (ACT) in serum of patients with cerebral ischemic stroke

BACKGROUND: Because of methods required for obtaining isolated left ventricular myocytes, evaluation of the contractile function of isolated left ventricular myocytes in normal human patients has been limited. Accordingly, the goal of the present study was to develop a means to isolate human left ventricular myocytes from small myocardial biopsy specimens collected from patients undergoing elective coronary artery bypass operations and to characterize indices of myocyte contractile performance. METHODS: Myocardial biopsy specimens were obtained from the anterior left ventricular free wall of 22 patients undergoing coronary artery bypass operations. Myocytes were isolated from these myocardial samples by means of a stepwise enzymatic digestion method and micro-trituration techniques. Isolated left ventricular myocyte contractile function was assessed by computer-assisted high-speed videomicroscopy under basal conditions and in response to beta-adrenergic receptor stimulation with isoproterenol. RESULTS: A total of 804 viable left ventricular myocytes were successfully examined from all of the myocardial biopsy specimens with an average of 37+/-4 myocytes per patient. All myocytes contracted homogeneously at a field stimulation of 1 Hz with an average percent shortening of 3.7%+/-0.1% and shortening velocity of 51.3+/-1.3 microm/s. After beta-adrenergic receptor stimulation with isoproterenol, percent shortening and shortening velocity increased 149% and 118% above baseline, respectively (P < .05). CONCLUSION: The unique results of the present study demonstrated that a high yield of myocytes could be obtained from human left ventricular biopsy specimens taken during cardiac operations. These myocytes exhibited stable contractile performance and maintained the capacity to respond to an inotropic stimulus. The methods described herein provide a basis by which future studies could investigate intrinsic and extrinsic influences on left ventricular myocyte contractility in human beings.     

Mitral valve strands and the risk of ischemic stroke in elderly patients. The French Study of Aortic Plaques in Stroke (FAPS) Investigators

BACKGROUND AND PURPOSE: Strands are thin and filamentous attachments on the cardiac valves shown by transesophageal echocardiography. Their nature and their potential for embolization are largely unknown. The objective was to estimate the risk of brain infarction in patients with mitral valve strands. METHODS: Using transesophageal echocardiography, we compared the frequency of strands on native mitral valves in 284 consecutive patients admitted with brain infarction and 276 control patients, all older than 60 years. In a second part, case subjects were followed up over a 2- to 4-year period, and the risk of recurrence of brain infarction was estimated in patients with and without strands. RESULTS: In the case-control study, mitral valve strands were found in 22.5% of the case patients and in 12.1% of the control subjects. In case subjects, mitral valve strands were more frequent in those with mitral valve dystrophy (52.4% versus 37.4%; P = .03). Strands were not associated with mitral valve prolapse, annular calcifications, or left atrial spontaneous echocardiographic contrast. After adjustment for age, sex, and mitral valve dystrophy, the odds ratio for ischemic stroke among patients with mitral strands was 2.2 (95% confidence interval, 1.4 to 3.6; P = .005). The frequency of strands was not different in patients with a known cause of brain infarction (24.4%) from that in patients with no other apparent cause (20.9%). During 646 per 100 person-years of follow-up, the incidence of recurrent brain infarction was 6.0 person-years in patients with strands and 4.2 in those without. In the Cox analysis, including potential confounders and poststroke treatment, mitral valve strands did not appear as independent predictors of recurrent brain infarction (relative risk, 1.3; 95% confidence interval, 0.5 to 3.0; P = .54). CONCLUSIONS: The present study shows an independent association between mitral valve strands and the risk of brain infarction. However, the lack of an increased relative risk of recurrence raises doubts about the potential causal relation with brain infarction in patients aged 60 years or older.     

Does PTCA in acute myocardial infarction affect mortality and reinfarction rates? A quantitative overview (meta-analysis) of the randomized clinical trials

BACKGROUND: Percutaneous transluminal coronary angioplasty (PTCA) is often performed after acute myocardial infarction (AMI) either as an adjuvant to thrombolytic therapy or instead of thrombolysis. The effect of PTCA in AMI on mortality and reinfarction has remained unclear, with the available randomized trials indicating inconsistent results. METHODS AND RESULTS: A systematic overview (meta-analysis) of the randomized trials was conducted to assess the effect of PTCA in AMI on mortality and reinfarction rates. Data from 7 trials in which primary PTCA was evaluated and 16 trials in which PTCA after thrombolysis was studied were included in this overview, comprising a total of 8496 patient. The trials represented different approaches to the timing of PTCA after AMI. The trials of PTCA after thrombolytic therapy were also categorized according to the different protocols with respect to the routine or elective character of PTCA in the invasive group. A reduction in short-term (6 week) mortality (odds ratio, 0.56; 95% CI, 0.33, 0.94) and in the combined outcome of short-term mortality and nonfatal reinfarction (odds ratio, 0.53; 95% CI, 0.35, 0.80) was observed in the trials comparing primary PTCA with thrombolytic therapy. In contrast, in trials in which an approach of thrombolysis and PTCA was compared with thrombolytic therapy alone, there was no important difference in early mortality, with an apparent reduction in mortality between 6 and 52 weeks. The lower mortality between 6 and 52 weeks among 6-week survivors seemed to be restricted to the subgroup of trials in which PTCA was used as a routine strategy (odds ratio, 0.58; 95% CI, 0.39, 0.87). CONCLUSIONS: Although the analyses of the various categories of trials suggest that primary PTCA may be more beneficial than thrombolytic therapy in AMI, these data should be interpreted cautiously unless confirmed by larger studies. In contrast, the addition of various other strategies of PTCA to thrombolytic therapy does not convincingly indicate a clinically different outcome than if a more conservative strategy is followed, in which PTCA is used only if clinically indicated. Some specific strategies, however, such as rescue PTCA in high-risk patients with occluded arteries, may be of benefit.     

Randomized comparison of direct thrombin inhibition versus heparin in conjunction with fibrinolytic therapy for acute myocardial infarction: results from the GUSTO-IIb Trial. Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes (GUSTO-IIb) Investigators

OBJECTIVES: We sought to show that hirudin might interact differently with streptokinase (SK) and tissue-type plasminogen activator (t-PA), which could reduce the incidence of death or reinfarction at 30 days. BACKGROUND: In a large-scale trial of patients with acute coronary syndromes, hirudin provided modest benefit compared with heparin. However, the interaction with thrombolytic agents was not specifically assessed. METHODS: Patients with symptoms of acute myocardial infarction and electrocardiographic ST segment elevation were treated with thrombolytic therapy and randomly assigned to receive hirudin or heparin. RESULTS: A total of 2,274 patients received t-PA, and 1,015 received SK. Baseline characteristics were balanced by antithrombin assignment. Among SK-treated patients, death or reinfarction at 30 days occurred more often in those treated with adjunctive heparin (14.4%) rather than hirudin (8.6%, odds ratio [OR] 1.78, 95% confidence interval [CI] 1.20 to 2.66, p = 0.004). Among t-PA-treated patients, the rates were 10.9% with heparin and 10.3% with hirudin (OR 1.06, 95% CI 0.81 to 1.38, p = 0.68; for treatment heterogeneity: chi-square 4.20, degrees of freedom [df] 1, p = 0.04). After adjustment for baseline differences between thrombolytic groups, the rates were 9.1% for SK with hirudin, 10.3% for t-PA with hirudin, 10.5% for t-PA with heparin and 14.9% for SK with heparin (for treatment heterogeneity: chi-square 4.5, df 1, p = 0.03), suggesting that the beneficial treatment effect of hirudin was limited to the SK-treated patients. CONCLUSIONS: Hirudin interacts favorably with SK but not t-PA, highlighting the importance of thrombin activity after SK therapy and the potential for simulating the effects of a more potent fibrinolytic agent through direct antithrombin therapy.     

A clinical trial comparing primary stenting of the infarct-related artery with optimal primary angioplasty for acute myocardial infarction: results from the Florence Randomized Elective Stenting in Acute Coronary Occlusions (FRESCO) trial

OBJECTIVES: This study sought to compare stenting of the primary infarct-related artery (IRA) with optimal primary percutaneous transluminal coronary angioplasty (PTCA) with respect to clinical and angiographic outcomes of patients with an acute myocardial infarction. BACKGROUND: Early and late restenosis or reocclusion of the IRA after successful primary PTCA significantly contributes to increased patient morbidity and mortality. Coronary stenting results in a lower rate of angiographic and clinical restenosis than standard PTCA in patients with angina and with previously untreated, noncomplex lesions. METHODS: After successful primary PTCA, 150 patients were randomly assigned to elective stenting or no further intervention. The primary end point of the trial was a composite end point, defined as death, reinfarction or repeat target vessel revascularization as a consequence of recurrent ischemia within 6 months of randomization. The secondary end point was angiographic evidence of restenosis or reocclusion at 6 months after randomization. RESULTS: Stenting of the IRA was successful in all patients randomized to stent treatment. At 6 months, the incidence of the primary end point was 9% in the stent group and 28% in the PTCA group (p=0.003); the incidence of restenosis or reocclusion was 17% in the stent group and 43% in the PTCA group (p=0.001). CONCLUSIONS: Primary stenting of the IRA, compared with optimal primary angioplasty, results in a lower rate of major adverse events related to recurrent ischemia and a lower rate of angiographically detected restenosis or reocclusion of the IRA.     

A randomized controlled trial of transcutaneous electrical nerve stimulation (CODETRON) to determine its benefits in a rehabilitation program for acute occupational low back pain

The authors report the results of a randomized controlled trial to examine the effectiveness of transcutaneous electrical nerve stimulation (TENS/CODETRON) when added to a standard exercise program for industrial workers with acute low back pain (LBP). Fifty-eight work-injured patients with LBP of 3-10 weeks duration were randomized into two groups that received actual or placebo stimulation in combination with the exercise regimen. The groups were compared on the primary outcome measures of disability, pain, and return to work. No significant differences between the experimental and placebo groups were discovered on any of the measured outcomes. Exercise alone, when continued over 4 weeks, reduced disability and pain scores significantly. Under the experimental conditions of this trial, no additional benefits of TENS/CODETRON were detected when added to an active exercise regimen.     

Randomized, double-blind comparison of hirulog versus heparin in patients receiving streptokinase and aspirin for acute myocardial infarction (HERO). Hirulog Early Reperfusion/Occlusion (HERO) Trial Investigators

BACKGROUND: Thrombolytic therapy improves survival after myocardial infarction through reperfusion of the infarct-related artery. Thrombin generated during thrombolytic administration may reduce the efficacy of thrombolysis. A direct thrombin inhibitor may improve early patency rates. METHODS AND RESULTS: Four hundred twelve patients presenting within 12 hours with ST-segment elevation were given aspirin and streptokinase and randomized in a double-blind manner to receive up to 60 hours of either heparin (5000 U bolus followed by 1000 to 1200 U/h), low-dose hirulog (0.125 mg/kg bolus followed by 0.25 mg x kg(-1) x h(-1) for 12 hours then 0.125 mg x kg(-1) x h(-1)), or high-dose hirulog (0.25 mg/kg bolus followed by 0.5 mg x kg(-1) x h(-1) for 12 hours then 0.25 mg x kg(-1) x h(-1)). The primary outcome was Thrombolysis In Myocardial Infarction trial (TIMI) grade 3 flow of the infarct-related artery at 90 to 120 minutes. TIMI 3 flow was 35% (95% CI, 28% to 44%) with heparin, 46% (95% CI, 38% to 55%) with low-dose hirulog, and 48% (95% CI, 40% to 57%) with high-dose hirulog (heparin versus hirulog, P=.023; heparin versus high-dose hirulog, P=.03). At 48 hours, reocclusion had occurred in 7% of heparin, 5% of low-dose hirulog, and 1% of high-dose hirulog patients (P=NS). By 35 days, death, cardiogenic shock, or reinfarction had occurred in 25 heparin (17.9%), 19 low-dose hirulog (14%), and 17 high-dose hirulog patients (12.5%) (P=NS). Two strokes occurred with heparin, none with low-dose hirulog, and two with high-dose hirulog. Major bleeding (40% from the groin site) occurred in 28% of heparin, 14% of low-dose hirulog, and 19% of high-dose hirulog patients (heparin versus low-dose hirulog, P<.01). CONCLUSIONS: Hirulog was more effective than heparin in producing early patency in patients treated with aspirin and streptokinase without increasing the risk of major bleeding. Direct thrombin inhibition may improve clinical outcome.     

Pharmacokinetics of 9-methoxy-N,N-dimethyl-5-nitropyrazolo [3,4, 5-kl]acridine-2(6H)-propanamine (PZA, PD 115934, NSC 366140) in mice: guidelines for early clinical trials1

Pharmacokinetic studies that consisted of measuring the plasma drug profile, tissue drug distribution, and elimination in urine and feces were performed in female C57BL/6 x DBA/2 (hereafter called B6D2F1) and male B6D2F1A/2 and C57BL/6 x CH3 (hereafter called B6C3F1) mice following treatment with a 1-h i.v. infusion of the PZA, PD115934 (NSC 366140). This drug is the first of a new class of cytotoxic agents and was selected for clinical trials because of both its broad antitumor activity in vivo against murine solid tumors and human xenografts, and its in vivo toxicity profile that was predictable based on drug dose and schedule of administration. The pharmacokinetic results obtained here in mice have been used to facilitate the dose escalations during the Phase I trial and to determine pharmacokinetic drug exposure targets for its acute and sub-acute toxic effects. Plasma samples from three to four mice per time point were pooled, and then individual tissue samples from the same mice were collected at specified times following treatment. All samples were prepared using solid-phase extraction and assayed using high pressure liquid chromatography. The acute dose-limiting toxicity was neurological and occurred immediately after treatment at 300 mg/m2. The peak plasma level range at the acute maximum tolerated dose was 1040-1283 ng/ml. Thus, peak plasma levels <1000 ng/ml were the acute toxicity target. Variations in the area under the plasma drug concentration x the time curve were observed that did not appear to be related to sex or age. The previously defined subacute dose-limiting toxicity was myelosuppression that occurred at a maximum tolerated dose of 600 mg/m2 (300 mg/m2 x 2) in B6D2F1 females. Thus, the area under the plasma drug concentration x the time curve in B6D2F1 females at this dose (1048 microg/ml x min) was the area under the plasma drug concentration x the time curve target. Drug levels were detected at 60 min following treatment in all tissues examined with a plasma:tissue ratio as high as 1:500. The organs with the highest levels were kidney, pancreas, liver, lung, and brain. Fecal excretion was low (range, 0.04-0.20% of the dose administered) and was not clearly different between males and females. Urinary excretion was higher (range, 5-28% of the dose administered) and did show evidence of sex-related differences, with male urinary drug excretion being higher than female urinary drug excretion. The drug was >/=95% protein bound. Preliminary evidence for drug metabolism was found in urine and feces and will be further explored.     

The importance of prognostic factors in the interpretation of two EORTC metastatic prostate cancer trials. European Organization for Research and Treatment of Cancer (EORTC) Genito-Urinary Tract Cancer Cooperative Group

Rehabilitation following anterior cruciate ligament (ACL) reconstruction is varied. Patients are usually prescribed an independent home exercise program, although some patients may attend physical therapy for additional supervised exercise. It is not known whether additional supervised exercise provides any further benefit. The purpose of this study was to compare efficacy for two types of rehabilitation following ACL reconstruction. A randomized controlled trial of 31 ACL-reconstructed patients was used to test the hypothesis that a home program plus supervised rehabilitation (Group S) is more effective than a home program (Group H) alone. Function, activity level, anterior tibial translation, and muscle strength were measured preoperatively and at 3 and 6 months postoperatively. Improvement of function, activity level, muscle strength, and anterior tibial translation was evident in both groups, but no significant differences were found between groups even though the sample size was sufficient to detect small treatment effects. It was concluded that supervised exercise, in addition to a home program, has minimal extra benefit for patients who have undergone ACL reconstruction.