Reduction In Ischemic Complications Research Articles

Clinical utility of a screening protocol for blunt cerebrovascular injury using computed tomography angiography.

OBJECTIVE Blunt cerebrovascular injury (BCVI) occurs in approximately 1% of the blunt trauma population and may lead to stroke and death. Early vascular imaging in asymptomatic patients at high risk of having BCVI may lead to earlier diagnosis and possible stroke prevention. The objective of this study was to determine if the implementation of a formalized asymptomatic BCVI screening protocol with CT angiography (CTA) would lead to improved BCVI detection and stroke prevention. METHODS Patients with vascular imaging studies were identified from a prospective trauma registry at a single Level 1 trauma center between 2002 and 2008. Detection of BCVI and stroke rates were compared during the 3-year periods before and after implementation of a consensus-based asymptomatic BCVI screening protocol using CTA in 2005. RESULTS A total of 5480 patients with trauma were identified. The overall BCVI detection rate remained unchanged postprotocol compared with preprotocol (0.8% [24 of 3049 patients] vs 0.9% [23 of 2431 patients]; p = 0.53). However, postprotocol there was a trend toward a decreased risk of stroke secondary to BCVI on a trauma population basis (0.23% [7 of 3049 patients] vs 0.53% [13 of 2431 patients]; p = 0.06). Overall, 75% (35 of 47) of patients with BCVI were treated with antiplatelet agents, but no patient developed new or progressive intracranial hemorrhage despite 70% of these patients having concomitant traumatic brain injury. CONCLUSIONS The results of this study suggest that a CTA screening protocol for BCVI may be of clinical benefit with possible reduction in ischemic complications. The treatment of BCVI with antiplatelet agents appears to be safe.

Glycoprotein IIb-IIIa Inhibitors in the Emergency Department for Patients with Non-ST-Elevation Acute Coronary Syndromes: Principles and Practices

Non-ST-elevation acute coronary syndrome is associated with significant morbidity and mortality. Although the benefit of platelet inhibition by glycoprotein (GP) IIb-IIIa inhibitors in patients undergoing percutaneous coronary intervention (PCI) is well established, emergency physicians and cardiologists have different perspectives regarding their optimum administration, especially upstream before PCI. In this article, two emergency physicians and two cardiologists analyze data and discuss relevant issues, including the ischemic benefits vs. the risk of bleeding associated with GP IIb-IIIa inhibitors in appropriate patients, for example, those with an elevated troponin level or who undergo revascularization. The emergency physicians support early identification of high-risk non-ST-elevation acute coronary syndrome patients and early administration of GP IIb-IIIa inhibitors, which are linked to improved patient outcomes. The cardiologists emphasize risk stratification to identify patients in whom the expected reduction in ischemic complications outweighs the risk of increased bleeding with these agents. GP IIb-IIIa inhibitors should be considered in patients with unstable angina and non-ST-segment elevation myocardial infarction (UA/NSTEMI) in whom PCI is planned, especially those with high-risk features or elevated serum troponin levels. It is reasonable to start this treatment upstream of intervention, pending further studies investigating the optimal timing of initiation of therapy in appropriate patients.

Efficacy of tenecteplase in combination with enoxaparin, abciximab, or unfractionated heparin: one-year follow-up results of the assessment of the safety of a new thrombolytic-3 (ASSENT-3) randomized trial in acute myocardial infarction

Background In the ASsessment of the Safety of a New Thrombolytic 3 (ASSENT-3) study, full-dose tenecteplase plus enoxaparin or half-dose tenecteplase plus abciximab reduced the frequency of ischemic complications of acute myocardial infarction, when compared to full-dose tenecteplase plus unfractionated heparin. The aim of the present study was to determine the effect of these fibrinolytic regimens on 1-year mortality. Methods and results Vital status at 1 year was available for 5942 patients (97.5%) of the 6095 initially enrolled in the study. At 1 year, 515 patients (8.7%) had died. Elderly or female patients and patients with low body weight, previous myocardial infarction, anterior wall myocardial infarction, and diabetes were at increased risk for death at 1 year. Mortality at 1 year was 7.9 % (n = 161) in the heparin group, 8.1% (n = 166) in the enoxaparin group, and 9.3% (n = 188) in the abciximab group ( P = .226). Overall, pairwise comparisons did not show a significant difference among treatment regimens: relative risk 1.03 (95% CI 0.82–1.30) for enoxaparin versus heparin ( P = .794) and relative risk 1.18 (95% CI 0.95–1.47) for abciximab versus heparin ( P = .144). However, 1-year outcome tended to be worse with abciximab in diabetic patients. Conclusion Mortality at 1 year after acute myocardial infarction remains high. Despite a reduction in ischemic complications after acute myocardial infarction with the use of full-dose tenecteplase plus enoxaparin or half-dose tenecteplase plus abciximab, mortality at 1 year was similar in these treatment groups.

Antiplatelet therapy for elective coronary stenting: a moving target.

The recognition of the major contribution of platelet-mediated mechanisms to the pathogenesis of thrombotic complications after coronary stenting has led to the development and evaluation of different antiplatelet regimens. The combination of aspirin and adenosine diphosphate antagonists such as ticlopidine and clopidogrel has solved the issue of acute stent thrombosis. The timing and dose of dual oral antiplatelet therapy have, however, changed over time with a shift from postintervention treatment to preintervention treatment with a high loading dose of clopidogrel. Pretreatment with aspirin and clopidogrel has been associated with a further 30% reduction in ischemic complications after coronary intervention. Recent data have even shown that in case of optimal pretreatment with such a dual oral antiplatelet therapy, glycoprotein IIb/IIIa antagonists are no longer mandatory for elective coronary stenting and should be reserved only for high-risk procedures or for acute coronary interventions.

A critical review of clinical trials for low-molecular-weight heparin therapy in unstable coronary artery disease.

Unstable angina and non-ST-segment elevation myocardial infarction (MI) are collectively referred to as unstable coronary artery disease (UCAD). They are conditions that share a common pathophysiology and represent frequently encountered, potentially life-threatening clinical manifestations of advanced atherosclerosis. Therefore, treatment of UCAD is a major focus for practicing clinicians, and although pharmacologic agents have been developed that impact on patient outcome, recent data suggest that a further reduction in ischemic complications is possible. Acute-phase treatment with aspirin is associated with a significant reduction in death and nonfatal MI in patients with UCAD. This benefit is enhanced by the addition of unfractionated heparin (UFH) to the treatment strategy; however, UFH requires careful monitoring and titration. In contrast, low-molecular-weight heparins (LMWHs), produced by chemical or enzymatic depolymerization of UFH, yield a predictable and consistent pharmacokinetic profile and anticoagulant response, making them an attractive treatment alternative to UFH in patients with UCAD. The optimal duration of treatment with LMWH is an important question influenced by the observation that reactivation of coagulation occurs following the early and abrupt discontinuation of heparin treatment. Early trials, such as FRISC and FRIC, demonstrated the benefit of acute therapy with dalteparin sodium; however, the results of extended treatment with dalteparin were inconclusive. The extended phase of these studies included relatively low-risk patients, and a once-daily, relatively low-dose strategy was employed. The findings derived from the FRISC II trial, which used a twice-daily dose of dalteparin, suggest a benefit for at least 60 days with extended treatment in high-risk patients with UCAD. Although an early-invasive treatment strategy is particularly beneficial, patients in whom early revascularization is not possible should be considered for extended treatment with dalteparin for up to 45 days, especially those awaiting percutaneous coronary intervention. Extended treatment with dalteparin therefore provides a protective "bridge" to enhance the outcome of patients with UCAD awaiting revascularization.

A highly significant 40% reduction in ischemic complications of percutaneous coronary intervention in 1995: Beginning of a new era?

A highly significant 40% reduction in ischemic complications of percutaneous coronary intervention in 1995: Beginning of a new era?

Antithrombotic agents in cerebral ischemia

The choice of antithrombotic agent in cerebral ischemia depends on the pathogenesis: thrombosis, embolism, or hemorrhage. Antiplatelet agents are considered most beneficial in thrombotic stroke, anticoagulants are most effective in cardioembolic stroke aantithrombotic agents are generally contraindicated in hemorrhagic stroke. A meta-analysis of 18 trials documented a 23% reduction in stroke risk with antiplatelet agents; aspirin is typically the antiplatelet agent of choice for stroke prevention. There are no definitive data regarding the optimal aspirin dose for stroke prevention and this issue remains controversial. Ticlopidine is the most effective anti-platelet agent, but its adverse effect profile restricts its use. Anticoagulants are highly effective for preventing cardioembolic stroke, but their effectiveness in non-cardioembolic stroke is uncertain because of lack of trial data. Results of the ongoing Warfarin/Aspirin Recurrent Stroke Study (warfarin [INR 1.8-2.8] vs aspirin [325 mg/day]) may clarify this issue. There is renewed interest in thrombolytics because recent data indicate that reperfusion within a few hours of stroke onset appears to be effective in preventing neutronal damage. In addition, when given within 6 hours of stroke onset, thrombolytics appear to be relatively safe. Several direct thrombin inhibitors are being evaluated. Experimentally, hirudin, hirulog, d-Phe- l-Pro- l-Arg-CH 2Cl (PPACK), and argatroban are clearly more effective than heparin in inhibiting platelet deposition and thrombus formation, and also show promise in preventing reocclusion after thrombolysis for both experimental thrombotic and embolic stroke. However, the risk of hemorrhage in patients with cerebrovascular disease is unknown for these agents. New antiplatelet agents, most of which inhibit the platelet llb/llla receptor, have also shown a significant reduction in ischemic complications in experimental thrombosis models.