Antiplatelet therapy in acute cerebral ischemia.
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BACKGROUND: Improved recognition of stroke signs and symptoms has paralleled the development of pharmacological strategies that may be examined to reduce stroke mortality and morbidity. Presently, tissue plasminogen activator is the only therapy that significantly improves outcome in acute stroke, with no agent demonstrating a significant reduction in mortality. SUMMARY OF REVIEW: Antiplatelet agents are a heterogenous class of drugs that have been successfully used for more than 2 decades in secondary stroke prevention. These agents include aspirin, with or without dipyridamole, and more recently, the adenosine antagonists ticlopidine and clopidogrel. However, studies of the use of antiplatelet agents within 48 hours of the ictus have examined only aspirin. Only 1 study, the Multicentre Acute Stroke Trial-Italy (MAST-I), entered patients within 6 hours of the ictus. These data suggest that an improvement in mortality may be related to the speed of administration. No significant adverse events were noted with early antiplatelet monotherapy. However, MAST-I did note a significant increase in early mortality in patients receiving aspirin plus streptokinase, a finding not adequately explained by an increase in the intracranial hemorrhage rate. CONCLUSIONS: The use of antiplatelet therapy in acute stroke, clinical or experimental, has only recently received attention. It is likely that the use of antiplatelet agents for acute stroke therapy will be less restrictive than that currently seen for thrombolytics. Future studies should include an examination of those agents that have previously demonstrated efficacy in secondary stroke prevention, most notably, aspirin. The recognition that all platelet stimuli share a final common pathway that is dependent on the surface glycoprotein IIb/IIIa (fibrinogen) receptor has resulted in the development of various agents which block this receptor and are currently the focus for clinical trials. The role of nitric oxide in stroke therapy will depend on minimizing the hypotensive side effects of this agent. Stroke models are needed to provide preliminary data on the efficacy of antiplatelet therapy, especially as relates to the interaction of antiplatelet agents with thrombolytics. (+info)
Use of fibrinolytic agents in the management of complicated parapneumonic effusions and empyemas.
(18/2653)
BACKGROUND: Standard treatment for pleural infection includes catheter drainage and antibiotics. Tube drainage often fails if the fluid is loculated by fibrinous adhesions when surgical drainage is needed. Streptokinase may aid the process of pleural drainage, but there have been no controlled trials to assess its efficacy. METHODS: Twenty four patients with infected community acquired parapneumonic effusions were studied. All had either frankly purulent/culture or Gram stain positive pleural fluid (13 cases; 54%) or fluid which fulfilled the biochemical criteria for pleural infection. Fluid was drained with a 14F catheter. The antibiotics used were cefuroxime and metronidazole or were guided by culture. Subjects were randomly assigned to receive intrapleural streptokinase, 250,000 IU daily, or control saline flushes for three days. The primary end points related to the efficacy of pleural drainage--namely, the volume of pleural fluid drained and the chest radiographic response to treatment. Other end points were the number of pleural procedures needed and blood indices of inflammation. RESULTS: The streptokinase group drained more pleural fluid both during the days of streptokinase/control treatment (mean (SD) 391 (200) ml versus 124 (44) ml; difference 267 ml, 95% confidence interval (CI) 144 to 390; p < 0.001) and overall (2564 (1663) ml versus 1059 (502) ml; difference 1505 ml, 95% CI 465 to 2545; p < 0.01). They showed greater improvement on the chest radiograph at discharge, measured as the fall in the maximum dimension of the pleural collection (6.0 (2.7) cm versus 3.4 (2.7) cm; difference 2.9 cm, 95% CI 0.3 to 4.4; p < 0.05) and the overall reduction in pleural fluid collection size (p < 0.05, two tailed Fisher's exact test). Systemic fibrinolysis and bleeding complications did not occur. Surgery was required by three control patients but none in the streptokinase group. CONCLUSIONS: Intrapleural streptokinase probably aids the treatment of pleural infections by improving pleural drainage without causing systemic fibrinolysis or local haemorrhage. (+info)
Relationship between TIMI frame count and clinical outcomes after thrombolytic administration. Thrombolysis In Myocardial Infarction (TIMI) Study Group.
(19/2653)
BACKGROUND: The corrected TIMI frame count (CTFC) is the number of cine frames required for dye to first reach standardized distal coronary landmarks, and it is an objective and quantitative index of coronary blood flow. METHODS AND RESULTS: The CTFC was measured in 1248 patients in the TIMI 4, 10A, and 10B trials, and its relationship to clinical outcomes was examined. Patients who died in the hospital had a higher CTFC (ie, slower flow) than survivors (69. 6+/-35.4 [n=53] versus 49.5+/-32.3 [n=1195]; P=0.0003). Likewise, patients who died by 30 to 42 days had higher CTFCs than survivors (66.2+/-36.4 [n=57] versus 49.9+/-32.1 [n=1059]; P=0.006). In a multivariate model that excluded TIMI flow grades, the 90-minute CTFC was an independent predictor of in-hospital mortality (OR=1.21 per 10-frame rise [95% CI, 1.1 to 1.3], an approximately 0.7% increase in absolute mortality for every 10-frame rise; P<0.001) even when other significant correlates of mortality (age, heart rate, anterior myocardial infarction, and female sex) were adjusted for in the model. The CTFC identified a subgroup of patients with TIMI grade 3 flow who were at a particularly low risk of adverse outcomes. The risk of in-hospital mortality increased in a stepwise fashion from 0.0% (n=41) in patients with a 90-minute CTFC that was faster than the 95% CI for normal flow (0 to 13 frames, hyperemia, TIMI grade 4 flow), to 2.7% (n=18 of 658 patients) in patients with a CTFC of 14 to 40 (a CTFC of 40 has previously been identified as the cutpoint for distinguishing TIMI grade 3 flow), to 6.4% (35/549) in patients with a CTFC >40 (P=0.003). Although the risk of death, recurrent myocardial infarction, shock, congestive heart failure, or left ventricular ejection fraction 20 to +info)
The effect of reduction of door-to-needle times on the administration of thrombolytic therapy for acute myocardial infarction.
(20/2653)
Optimal management of acute myocardial infarction requires rapid administration of thrombolytic therapy. However, only patients who fulfill the following specific criteria are likely to benefit from this treatment: admission within 12 hours of the onset of symptoms, no contraindications, ST elevation or possible new-onset left bundle branch block on the admission electrocardiogram. We employed an aggressive policy to reduce the delay between admission to hospital and the administration of thrombolysis (the 'door-to-needle time'), and investigated whether this approach affected the accuracy of administration of thrombolysis. Patients admitted to the cardiac care unit with acute myocardial infarction, or who were thrombolysed, were identified retrospectively over two equivalent 4-month periods before and after implementation of our policy. Patients were considered eligible for thrombolysis if they fulfilled the criteria mentioned above. The mean (SD) door-to-needle time for all patients who received thrombolysis on admission decreased from 61(70) to 19(20) minutes (p = 0.0004). The proportion of patients eligible for thrombolysis who received treatment increased from 24/38 to 30/30 (p = 0.0002). However, the proportion of patients receiving thrombolysis who did not fulfill our criteria also increased, from 3/27 to 11/41 (p = 0.1). There were no complications of thrombolysis in the first study period, but two cerebrovascular accidents in the second period; both patients fulfiled our criteria for treatment. We conclude that simple educational measures greatly reduced door-to-needle times and led to a higher proportion of eligible patients receiving thrombolysis. However, greater pressure on medical staff to make rapid management decisions increased the proportion of patients being thrombolysed inappropriately. (+info)
Hospital mortality of acute myocardial infarction in the thrombolytic era.
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OBJECTIVE: To examine the management and outcome of an unselected consecutive series of patients admitted with acute myocardial infarction to a tertiary referral centre. DESIGN: A historical cohort study over a three year period (1992-94) of consecutive unselected admissions with acute myocardial infarction identified using the HIPE (hospital inpatient enquiry) database and validated according to MONICA criteria for definite or probable acute myocardial infarction. SETTING: University teaching hospital and cardiac tertiary referral centre. RESULTS: 1059 patients were included. Mean age was 67 years; 60% were male and 40% female. Rates of coronary care unit (CCU) admission, thrombolysis, and predischarge angiography were 70%, 28%, and 32%, respectively. Overall in-hospital mortality was 18%. Independent predictors of hospital mortality by multivariate analysis were age, left ventricular failure, ventricular arrhythmias, cardiogenic shock, management outside CCU, and reinfarction. Hospital mortality in a small cohort from a non-tertiary referral centre was 14%, a difference largely explained by the lower mean age of these patients (64 years). Five year survival in the cohort was 50%. Only age and left ventricular failure were independent predictors of mortality at follow up. CONCLUSIONS: In unselected consecutive patients the hospital mortality of acute myocardial infarction remains high (18%). Age and the occurrence of left ventricular failure are major determinants of short and long term mortality after acute myocardial infarction. (+info)
Acute assessment of microvascular perfusion patterns by myocardial contrast echocardiography during myocardial infarction: relation to timing and extent of functional recovery.
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OBJECTIVE: To examine the relation between the initial microvascular perfusion pattern, as assessed by intracoronary myocardial contrast echocardiography (MCE), immediately after restoration of TIMI (thrombolysis in myocardial infarction) (TIMI) grade 3 flow during acute myocardial infarction, and the extent and timing of functional recovery in the area at risk. SETTING: Referral centre for interventional cardiology. METHODS: Intracoronary MCE was performed 15 minutes after TIMI grade 3 recanalisation of the infarct artery in 25 patients. Segmental myocardial contrast patterns were graded semiquantitatively (0, none; 0.5, heterogeneous; 1, homogeneous). Functional recovery was assessed by echocardiography on days 9 and 42. RESULTS: Among 174 myocardial segments in the area at risk, wall motion recovery on day 9 was observed in 40% of MCE grade 1 segments but there was no significant recovery in grade 0 or 0.5 segments. On day 42, recovery had occurred in 56% of MCE grade 1 segments (p < 0. 0001 v MCE grade 0 and 0.5; p = 0.0001 v MCE grade 1 on day 9), and 22% of MCE grade 0.5 segments (p = 0.02 v MCE grade 0; p = 0.0005 v MCE grade 0.5 on day 9); MCE grade 0 segments did not recover. Negative predictive value in predicting recovery by contrast enhancement was 95% and 89% by days 9 and 42, respectively. CONCLUSIONS: Contractile recovery occurs earliest in well reperfused segments. Up to one quarter of segments with heterogeneous contrast enhancement show wall motion recovery within the first six weeks. Myocardial perfusion after recanalisation in acute myocardial infarction, even if heterogeneous, is a prerequisite for postischaemic functional recovery. Thus preservation of acute myocardial perfusion is associated with more complete and early functional recovery. (+info)
Empirical treatment with fibrinolysis and early surgery reduces the duration of hospitalization in pleural sepsis.
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The efficacy of three different treatment protocols was compared: 1) simple chest tube drainage (Drain); 2) adjunctive intrapleural streptokinase (IP-SK); and 3) an aggressive empirical approach incorporating SK and early surgical drainage (SK+early OP) in patients with pleural empyema and high-risk parapneumonic effusions. This was a nonrandomized, prospective, controlled time series study of 82 consecutive patients with community-acquired empyema (n=68) and high-risk parapneumonic effusions (n=14). The following three treatment protocols were administered in sequence over 6 years: 1) Drain (n=29, chest catheter drainage); 2) IP-SK (n=23, adjunctive intrapleural fibrinolysis with 250,000 U x day(-1) SK); and 3) SK+early OP (n=30, early surgical drainage was offered to patients who failed to respond promptly following initial drainage plus SK). The average duration of hospital stay in the SK+early OP group was significantly shorter than in the Drain and IP-SK groups. The mortality rate was also significantly lower in the SK+early OP than the Drain groups (3 versus 24%). It was concluded that an empirical treatment strategy which combines adjunctive intrapleural fibrinolysis with early surgical intervention results in shorter hospital stays and may reduce mortality in patients with pleural sepsis. (+info)
Cardiorespiratory efficacy of thrombolytic therapy in acute massive pulmonary embolism: identification of predictive factors.
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The aim of this study was to evaluate the contribution of clinical, angiographic and haemodynamic findings in predicting the cardiorespiratory efficacy of thrombolytic therapy in acute massive pulmonary embolism. Haemodynamic measurements and pulmonary angiography were performed before (H0) and 12 h after (H12) initiating thrombolytic therapy in 23 patients with acute massive pulmonary embolism (Miller index > or =20/34), and free of prior cardiopulmonary disease. Patients were divided into two groups according to the variation in oxygen delivery (deltaDO2) between H0 and H12: deltaDO2 >20% (responders, n=10) and deltaDO2 < or =20% (nonresponders, n=13). Before thrombolysis, clinical and angiographic findings were similar in both groups. Mean right atrial pressure (RAP) and total pulmonary (vascular) resistance (TPR) were higher, while cardiac index (CI), DO2 and mixed venous oxygen saturation (Sv,O2) were lower in responders. DO2 and Sv,O2 were more closely correlated with deltaDO2 than RAP, TPR and CI. Eight out of the 10 responders and two out of the 13 nonresponders had an Sv,O2 <55%, while nine of the responders and two of the nonresponders had a DO2 <350 mL x min(-1) x m(-2). In conclusion, the initial oxygen delivery and mixed venous oxygen saturation may predict the cardiorespiratory efficacy of thrombolytic therapy in acute massive pulmonary embolism. When pulmonary angiography is performed, measurement of mixed venous oxygen saturation may be a simple method by which to select patients for thrombolytic therapy. (+info)