Integrating antithrombin and antiplatelet therapies with early invasive management for non-ST-segment elevation acute coronary syndromes

Non-ST-segment elevation acute coronary syndromes are a dramatic manifestation of coronary artery disease. Multiple clinical trials have shown that early cardiac catheterization improves clinical outcomes in patients with non-ST-segment elevation acute coronary syndromes. Many antithrombotic agents effectively manage unstable coronary syndromes and serve as adjuncts to percutaneous coronary intervention. Yet, the growing number of pharmacologic agents makes early management of non-ST-segment elevation acute coronary syndromes increasingly complex. We review the current evidence regarding the optimal integration of early antithrombotic and antiplatelet therapies with early coronary angiography and subsequent revascularization.     

Revised guidelines for the management of non-ST-segment elevation acute coronary syndromes

Unstable angina (UA) and non-ST-segment elevation myocardial infarction (NSTEMI) refer to a spectrum of acute severe cardiac disorders characterized by myocardial oxygen demand and supply mismatch, caused by atherosclerotic coronary artery disease. Patients presenting with acute coronary syndromes represent a major medical problem, accounting for 2.5 million hospitalizations and 500,000 deaths annually in the United States alone. Of these, 1.5 million have a final diagnosis of UA, and myocardial infarction (ST-segment and non-ST-segment elevation) accounts for the remaining 1 million. The management of UA/NSTEMI presents a challenge to the cardiologist because treatment strategies continue to evolve. A number of trials have now assessed the safety and efficacy of early revascularization strategies in the treatment of patients with UA/NSTEMI, whereas others have focused on pharmacologic adjunctive therapy. An optimal single strategy encompassing most patients’ needs is not clear. This review focuses on the revised American College of Cardiology/ American Heart Association guidelines for the management of patients presenting with UA/NSTEMI.     

介入治疗非ST段抬高的急性冠状动脉综合征

目的　观察介入治疗非ST段抬高的急性冠状动脉综合征 (acutecoronarysyndromes ,ACS)的安全性及临床效果。方法　 16 5例ACS患者 ,接受急诊介入治疗的 89例 ,经内科治疗病情改善后再介入治疗的 76例。所有“罪犯”病变均予治疗 ,其中 4 1例患者同时接受了“罪犯”与非“罪犯”病变血管的治疗。介入方法有经皮冠状动脉腔内成形术 (PTCA) +支架、直接植入支架及切割球囊扩张。结果　 16 5处“罪犯”病变PTCA后植入支架 134枚 ,直接植入支架 4 8枚。术后残余狭窄均 <10 % ;前向血流达TIMI 3级 ;136例患者心绞痛消失 ,11例有不典型胸痛 ,2 4h后消失 ;术前仅有胸闷症状的 18例患者 ,术后 15例消失 ,3例减轻 ;无术中死亡及急诊冠状动脉旁路移植术 (CABG)病例。随访 139例患者 2～ 18个月 ,2 0例再发心绞痛 ,有 14例冠状动脉造影提示再狭窄 ,其中 11例再次行PTCA ,1例PTCA +支架 ,2例接受外科CABG ;无急性心肌梗死、猝死及心功能恶化发生。结论　在条件具备的介入中心 ,由经验丰富和技术娴熟的介入治疗医生施行或在其指导下 ,对非ST段抬高的ACS患者进行介入治疗是积极有效的治疗措施 ,近、远期临床效果较满意 ,手术成功率及安全性较高     

Contemporary approach to the diagnosis and management of non-ST-segment elevation acute coronary syndromes

The management of patients with acute coronary syndromes (ACS) has evolved dramatically over the past decade and, in many respects, represents a rapidly moving target for the cardiologist and internist who seek to integrate these recent advances into contemporary clinical practice. Unstable angina and non-ST-segment elevation myocardial infarction (MI) comprise a growing percentage of patients with ACS and is emerging as a major public health problem worldwide, especially in Western countries, despite significant improvements and refinements in management over the past 20 years. Against this backdrop of a multitude of randomized, controlled clinical trials that have established the scientific foundation upon which evidence-based treatment strategies have emerged and become increasingly refined, the clinician is frequently confronted with panoply of choices that can create uncertainty or confusion regarding "optimal management". While the debate about the ideal approach to the management of non-ST-segment elevation (NSTE) ACS (i.e., routine "early invasive strategy" versus an "ischemia-guided", or "conservative", strategy) has been ongoing for over a decade, clinical trials results provide compelling evidence that intermediate- and high-risk ACS patients derived significant reductions in both morbidity and mortality with mechanical or surgical intervention, especially when revascularization is coupled with aggressive, multifaceted (anti-platelet, antithrombin, anti-ischemic and anti-atherogenic) medical therapy along with risk factor modification. For these reasons, it seems especially timely and appropriate to present a state-of-the-art paper that reviews the latest advances in the management of NSTE ACS, mindful of the fact that even this noble effort to synthesize and integrate a prodigious amount of scientific information and cardiovascular therapeutics is destined to evolve still further as our full-scale assault on optimizing clinical outcomes by harmonizing the advances in mechanical and pharmacologic interventions continues unabated.     

早期有创干预对高危无ST段抬高急性冠状动脉综合征近远期预后的影响

目的探讨早期有创干预对高危无ST段抬高急性冠状动脉综合征(ACS)患者的近远期预后影响。方法2001年10月至2003年10月期间连续入院的无ST段抬高ACS患者545例,随机分成早期保守治疗组(284例)与早期有创干预组(261例),随访患者30d与6个月的复合心血管事件(包括心脏性死亡、非致命性心肌梗死、非致命性心力衰竭、因反复缺血性心绞痛发作住院),评价早期有创干预对肌钙蛋白(Tn)Ⅰ或高敏感C反应蛋白(hs-CRP)水平增高的高危患者近、远期预后的影响。结果与早期保守治疗组比较,早期有创干预降低随访30d时的反复心绞痛发作住院事件及随访30d与6个月时的复合心血管事件(P值均<0·05);亚组分析示早期有创干预可明显降低TnI增高或hs-CRP增高患者30d及6个月的复合心血管事件及6个月硬性终点事件发生率(均P值<0·01),对TnI或hs-CRP水平正常者,早期有创干预无明显优势。结论早期有创干预能明显降低TnI或hs-CRP水平增高的高危患者的心血管事件,改善患者的近、远期预后。     

坚持循证医学原则,规范诊治非ST段抬高的急性冠状动脉综合征

中华医学会心血管病学分会和中华心血管病杂志编辑委员会根据近年来有关的临床试验结果,参考美国心脏病学会（ACC）／美国心脏协会（AHA）／欧洲心脏病学会（ESC）等有关国际学术机构新近修订的指南,并结合我国急性冠状动脉综合征（acute coronary syndrome,ACS）防治的经验,组织有关专家制定了我国不稳定性心绞痛（unstable angina,UA）和非ST段抬高心肌梗死（non-ST elevation myocardial infarction,NSTEMI）诊断与治疗指南（以下简称指南）。我们希望该指南能够提高我国UA／NSTEMI的诊治水平,推动医疗实践的规范化。     

Chronic kidney disease in patients with non-ST-segment elevation acute coronary syndromes

Purpose

Chronic kidney disease has been linked to high mortality rates in patients with ST-segment elevation myocardial infarction but has not been well described for patients with non-ST-segment elevation acute coronary syndromes. We examined the treatment and outcomes of patients with both non-ST-segment elevation acute coronary syndromes and moderate to severe chronic kidney disease.

Subjects and Methods

We evaluated 45 343 patients with non-ST-segment elevation acute coronary syndromes enrolled in the CRUSADE Quality Improvement Initiative and compared treatments and outcomes in patients with and without moderate to severe chronic kidney disease.

Results

Patients presenting with moderate to severe chronic kidney disease (n = 6560) were older, more often diabetic, and more likely to present with signs of congestive heart failure. Adherence to Class IA/IB guidelines recommendations was lower in patients with moderate to severe chronic kidney disease, who were significantly less likely to be treated with medications, undergo invasive cardiac procedures, and be given discharge counseling. Moderate to severe chronic kidney disease was associated with a 50% increased risk of mortality and a 70% increased likelihood of transfusion. Despite having a higher risk of adverse outcomes, patients with moderate to severe chronic kidney disease were treated less aggressively than patients with normal renal function.

Conclusions

These findings suggest that, in patients with moderate to severe chronic kidney disease, safety concerns about adverse outcomes and the absence of trial data for this population may limit the use of guidelines-recommended therapies and interventions for non-ST-segment elevation acute coronary syndromes. The decreased use of discharge counseling in patients with moderate to severe chronic kidney disease and non-ST-segment elevation acute coronary syndromes may represent therapeutic nihilism.     

Regional outcomes after admission for high-risk non-ST-segment elevation acute coronary syndromes

Purpose

An analysis of reginal variation across the United States in the treatment and outcomes of patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS) has not been previously performed.

Subjects and Methods

We assessed contemporary practice and outcomes in 56,466 high-risk patients with NSTE ACS (positive cardiac markers and/or ischemic ST-segment changes) admitted to 310 hospitals across four defined regions in the United States from January 1, 2001, to September 30, 2003. Patient clinical characteristics, acute (<24 hours) and discharge medications, in-hospital procedures, and in-hospital case-fatality rates were evaluated.

Results

Statistically significant but clinically small differences in baseline characteristics including age, gender, rates of diabetes, hypertension, and smoking, as well as medical treatment, including a greater than 5% variation in acute use of beta-blockers, clopidogrel, and statins use, were noted across regions. Adjusted rates of revascularization were similar across regions. Overall in-hospital case-fatality rate was 4.1%, with the highest rates in the Midwest (4.6%) and the lowest in the Northeast (3.5%). Adjusted odds ratios (OR) (95% confidence interval [CI] for death were significantly higher in the Midwest (OR 1.42, CI 1.19-1.70), West (OR 1.40 CI 1.05-1.87), and South (OR 1.33, CI 1.08-1.62), compared with the Northeast.

Conclusions

Management of high-risk patients with NSTE ACS is relatively uniform across the United States. However, in-hospital case-fatality rates vary significantly by region, and the differences are not explained by adjustment for standard clinical variables.     

Percutaneous coronary intervention in diabetic patients with non-ST-segment elevation acute coronary syndromes.

Key pathophysiologic mechanisms of diabetes-related coronary disease include inflammation and a prothrombotic state. In the setting of non-ST-segment elevation acute coronary syndromes diabetic patients are at high risk for subsequent cardiovascular events. At the same time, they derive greater benefit than non-diabetic counterparts from aggressive antithrombotic therapy, early coronary angiography, and stent-based percutaneous coronary intervention. The mainstays of antithrombotic therapy for diabetic patients undergoing percutaneous revascularization include aspirin, clopidogrel, platelet glycoprotein IIb/IIIa receptor antagonists, and heparin or low-molecular-weight heparin. Despite dramatic reduction in restenosis conferred by drug-eluting stents, diabetic patients remain at increased risk for repeat revascularization. More efforts are needed both in terms of local drug elution as well as systemic pharmacologic therapies to further contain the excessive neointimal proliferation that characterizes the diabetic response to vascular injury.     

曲美他嗪治疗非ST抬高急性冠脉综合征的临床观察

目的：观察曲美他嗪与常规药物相结合治疗非ST段抬高的急性冠脉综合征（NSTEACS）的疗效。方法：60例NSTEACS被随机分为治疗组及对照组各30例,对照组常规给予硝酸酯类、抗血小板药物、β受体阻滞剂、低分子肝素;治疗组在常规治疗的基础上加用曲美嗪20mg,3次/d,连续观察4周,观察胸痛消失率、动态心电图的变化（ST-T改变及恶性心律失常发生率）及心率,血压的变化。结果：治疗组胸痛消失率、ST-T改善更为明显,恶性心律失常发生率明显减少（P〈0.05）,曲美他嗪对心率、血压无影响（P〉0.05）。结论：在常规治疗NSTEACS基础上联合应用曲美他嗪可以改善心肌缺血,减少胸痛的发作次数及恶性心律失常发生率,对血液动力学无影响,是安全、有效的治疗方法。     

Assessment of non-ST-segment elevation acute coronary syndromes with cardiac magnetic resonance imaging

OBJECTIVES: The goal of this study was to determine: 1) if the presence of significant coronary stenosis in patients presenting with non-ST-segment elevation acute coronary syndromes (NSTE-ACS) can be predicted by cardiac magnetic resonance (CMR) imaging; and 2) if the analysis of several CMR methods improves its diagnostic yield compared with analysis of individual methods. BACKGROUND: With modern acquisition techniques, several CMR methods for the assessment of coronary artery disease (CAD) can be combined in a single noninvasive scanning session. Such a multicomponent CMR examination has not previously been applied to a large patient population, in particular those with a high prevalence of CAD in an acute situation. METHODS: Sixty-eight patients presenting with NSTE-ACS underwent CMR imaging of myocardial function, perfusion (rest and adenosine-stress), viability (by late contrast enhancement), and coronary artery anatomy. Visual analysis of CMR was carried out. First, all CMR data were reviewed in combination ("comprehensive analysis"). In further separate analyses, each CMR method was analyzed individually. The ability of CMR to detect coronary stenosis >/=70% on X-ray angiography was determined. RESULTS: Comprehensive CMR analysis yielded a sensitivity of 96% and a specificity of 83% to predict the presence of significant coronary stenosis and was more accurate than analysis of any individual CMR method; CMR was significantly more sensitive and accurate than the Thrombolysis In Myocardial Infarction risk score (p < 0.001). CONCLUSIONS: Cardiac magnetic resonance imaging accurately predicts the presence of significant CAD in patients with NSTE-ACS. In this study, a comprehensive analysis of several CMR methods improved the accuracy of the test.     

Acute medical management of the non-ST-segment elevation acute coronary syndromes (NSTE-ACS) in older patients

Older patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) represent many clinical challenges. For example diagnosis can be difficult, and comorbidities are common. Furthermore, NSTE-ACS is particularly common in older patients (>60% of acute myocardial infarctions occurring in patients aged 65 years or older) and the mortality associated with NSTE-ACS is particularly high. Despite these many concerns, evidence from clinical trials based on this group of patients is limited. Future prospective clinical trials should therefore more accurately reflect the NSTE-ACS patient population by including more elderly patients and including efficacy endpoints that are relevant for these patients. Furthermore, the lack of clear clinical evidence in this population means that the current treatment guidelines do not fully address the needs of elderly patients. Several recent clinical trials have highlighted some of the main considerations we should make when treating elderly patients with NSTE-ACS. Different therapy options in the pharmacological management of NSTE-ACS in this age group are also discussed.