beta-Blockers and reduction of cardiac events in noncardiac surgery: clinical applications

Recent studies suggest that -blockers administered perioperatively may reduce the risk of adverse cardiac events and mortality in patients who have cardiac risk factors and undergo major noncardiac surgery. The objective of this article is to provide practicing physicians with examples of perioperative -blocker use in practice by using several hypothetical cases. Although current evidence describing the effectiveness of perioperative -blockade may not address all possible clinical situations, it is possible to formulate an evidence-based approach that will maximize benefit to patients. We describe how information from several sources can be used to guide management of patients with limited exercise tolerance, those at highest risk for perioperative cardiac events, patients who are taking -blockers long-term, and those with relative contraindications to -blockade. Even though fine points of their use remain to be elucidated, perioperative -blocker use is important and can be easily applied in practice by any physician involved with the care of patients perioperatively.      

Surveillance and prevention of major perioperative ischemic cardiac events in patients undergoing noncardiac surgery: a review

THIS IS THE SECOND OF 2 ARTICLES EVALUATING cardiac events in patients undergoing noncardiac surgery. Unrecognized myocardial infarctions (MIs) are common, and up to 50% of perioperative MIs may go unrecognized if physicians rely only on clinical signs or symptoms. In this article, we summarize the evidence regarding monitoring strategies for perioperative MI in patients undergoing noncardiac surgery. Perioperative troponin measurements and 12-lead electrocardiograms can detect clinically silent MIs and provide independent prognostic information. Currently, there are no standard diagnostic criteria for perioperative MIs in patients undergoing noncardiac surgery. We propose diagnostic criteria that reflect the unique features of perioperative MIs. Finally, we review the evidence for perioperative prophylactic cardiac interventions. There is encouraging evidence that some perioperative interventions (e.g., β-blockers, α₂-adrenergic agonists, statins) may prevent major cardiac ischemic events, but firm conclusions await the results of large definitive trials. The best evidence does not support a management strategy of preoperative coronary revascularization before noncardiac surgery.     

Perioperative cardiac events in patients undergoing noncardiac surgery: a review of the magnitude of the problem, the pathophysiology of the events and methods to estimate and communicate risk

THIS IS THE FIRST OF 2 ARTICLES EVALUATING cardiac events in patients undergoing noncardiac surgery. In this article, we review the magnitude of the problem, the pathophysiology of these events, approaches to risk assessment and communication of risk. The number of patients undergoing noncardiac surgery worldwide is growing, and annually 500 000 to 900 000 of these patients experience perioperative cardiac death, nonfatal myocardial infarction (MI) or nonfatal cardiac arrest. Although the evidence is limited, a substantial proportion of fatal perioperative MIs may not share the same pathophysiology as nonoperative MIs. A clearer understanding of the pathophysiology is needed to direct future research evaluating prophylactic, acute and long-term interventions. Researchers have developed tools to facilitate the estimation of perioperative cardiac risk. Studies suggest that the Lee index is the most accurate generic perioperative cardiac risk index. The limitations of the studies evaluating the ability of noninvasive cardiac tests to predict perioperative cardiac risk reveals considerable uncertainty as to the role of these popular tests. Similarly, there is uncertainty as to the predictive accuracy of the American College of Cardiology / American Heart Association algorithm for cardiac risk assessment. Patients are likely to benefit from improved estimation and communication of cardiac risk because the majority of noncardiac surgeries are elective and accurate risk estimation is important to allow informed patient and physician decision-making.     

Assessing risk factors of perioperative major cardiac events in elderly patients with coronary heart disease undergoing noncardiac surgery

To the editor： In a retrospective observational clinical study including 482 elderly patients with coronary heart diseaseundergoing elective major noncardiac surgery, Liu et al＇ showed that the incidence ofperioperative major adverse cardiac events （MACEs） was 12.7%, and five risk factors were independently associated with perioperative MACEs. This study makes an important contribution to the effort to define risk factors for perioperative MACEs in elderly patients with coronary heart disease undergoing noncardiac surgery. Strengths of this study include a large sample of patients and most of the known risk factors that can affect perioperative MACEs. Furthermore, the authors have used appropriate methods to identify independent risk factors for perioperative MACEs. However, in our view, there are several aspects of this study that should be considered.     

Risk factors for perioperative major cardiac events in Chinese elderly patients with coronary heart disease undergoing noncardiac surgery

Background Few studies have investigated perioperative major adverse cardiac events (MACEs) in elderly Chinese patients with coronary heart disease (CHD) undergoing noncardiac surgery.This study examin...     

Right heart catheterization and cardiac complications in patients undergoing noncardiac surgery: an observational study

CONTEXT: Right heart catheterization (RHC) is commonly performed before high-risk noncardiac surgery, but the benefit of this strategy remains unproven. OBJECTIVE: To evaluate the relationship between use of perioperative RHC and postoperative cardiac complication rates in patients undergoing major noncardiac surgery. DESIGN: Prospective, observational cohort study. SETTING: Tertiary care teaching hospital in the United States. PATIENTS: Patients (n = 4059 aged >/=50 years) who underwent major elective noncardiac procedures with an expected length of stay of 2 or more days between July 18, 1989, and February 28, 1994. Two hundred twenty one patients had RHC and 3838 did not. MAIN OUTCOME MEASURE: Combined end point of major postoperative cardiac events, including myocardial infarction, unstable angina, cardiogenic pulmonary edema, ventricular fibrillation, documented ventricular tachycardia or primary cardiac arrest, and sustained complete heart block, classified by a reviewer blinded to preoperative data. RESULTS: Major cardiac events occurred in 171 patients (4.2%). Patients who underwent perioperative RHC had a 3-fold increase in incidence of major postoperative cardiac events (34 [15.4%] vs 137 [3.6%]; P<.001). In multivariate analyses, the adjusted odds ratios (ORs) for postoperative major cardiac and noncardiac events in patients undergoing RHC were 2.0 (95% confidence interval [CI], 1.3-3.2) and 2.1 (95% CI, 1.2-3.5), respectively. In a case-control analysis of a subset of 215 matched pairs of patients who did and did not undergo RHC, adjusted for propensity of RHC and type of procedure, patients who underwent perioperative RHC also had increased risk of postoperative congestive heart failure (OR, 2.9; 95% CI, 1.4-6.2) and major noncardiac events (OR, 2.2; 95% CI, 1.4-4.9). CONCLUSIONS: No evidence was found of reduction in complication rates associated with use of perioperative RHC in this population. Because of the morbidity and the high costs associated with RHC, the impact of this intervention in perioperative care should be evaluated in randomized trials.     

BNP和老年非心脏手术心血管事件的关系

目的 探讨术前B型纳尿肽（BNP）浓度和老年非心脏手术心血管事件的关系。方法 依据术前血浆BNP浓度将101例择期行非心脏手术患者分为两组,A组（n=61）：BNP浓度≤100ng／L;B组（n=40）：BNP浓度〉100ng／L,比较两组患者术后心脏事件发生情况及心脏事件组和非心脏事件组13NP浓度。结果 A组无心脏事件发生,B组中有14例发生心脏事件,两组比较差异有统计学意义（P〈0．05）,心脏事件组术前血浆BNP浓度（223．9&#177;92．3）ng／L,无心脏事件组术前血浆BNP浓度（58．7&#177;29．8）ng／L,两组比较差异有统计学意义（P〈0．05）。结论 术前血浆BNP浓度〉100ng／L的老年人非心脏手术后可能发生心脏事件。     

beta-Blockers in heart failure: clinical applications

-Blockers reduce morbidity and mortality in heart failure patients with left ventricular systolic dysfunction and stable fluid status. The successful adoption of -blocker guidelines for these patients requires an understanding of the value of this therapy and effective systems to maintain safety and ensure high quality of care. This article distills scientific evidence and consensus guidelines into a series of cases and practical answers about patient selection, discussions with patients, management and monitoring, and systems improvements to optimize quality of care, safety, and benefit for all patients with heart failure.      

长托宁用于心脏病人非心脏手术前用药的临床研究

[目的]探讨长托宁作为心脏病人非心脏手术前用药的临床效果。[方法]ASAⅡ-Ⅲ级的稿人50例,随机分为长托宁组和东莨菪碱组,免用术前药,入室后肌注长托宁0．01mg／kg和东莨菪碱0．006mg／kg,40min后开始麻醉和手术。记录给药前、给药后10、20、30、40min时的心率（HR）、血压（Bp）变化情况及观察病人镇静、口干程度。[结果]Ⅰ组SBP在给药后30、40min时低于给药前;DBP在20、30、40min时较给药前低;HR在20、30min时较给药前低,（P〈0．05）。Ⅱ组SBP、DBP在给药后30min时均较用药前高,且明显高于I组,（P〈0．05）。HR在20、30、40min时高于给药前,且较Ⅰ组明显增快,（P〈0．05）。组间比较口干与镇静程度均没有显著差异。[结论]长托宁作为心脏病人非心脏手术前用药较东莨菪碱效果好。     

Long-term cardiac prognosis following noncardiac surgery. The Study of Perioperative Ischemia Research Group.

OBJECTIVE--To determine the long-term (2-year) cardiac prognosis of high-risk patients undergoing noncardiac surgery and to determine the predictors of long-term adverse cardiac outcome. DESIGN--Prospective cohort study. Historical, clinical, and laboratory data were collected during the in-hospital period, and at 6 months, 1 year, and 2 years following surgery. Data were analyzed using proportional hazards models. SETTING--University-affiliated Veterans Affairs medical center. POPULATION--A consecutive sample of 444 patients with or at high risk for coronary artery disease who had undergone elective noncardiac surgery and were discharged from the hospital in stable condition. MAIN OUTCOME MEASURES--Cardiac death, myocardial infarction, unstable angina, progressive angina requiring coronary artery bypass graft surgery or coronary angioplasty, and new unstable angina requiring hospitalization. RESULTS--Forty-seven patients (11%) had major cardiovascular complications during a 728-day (median) follow-up period: 24 had cardiac death; 11, nonfatal myocardial infarction; six, progressive angina requiring coronary artery bypass graft surgery or coronary angioplasty; and six, new unstable angina requiring hospitalization. Thirty percent of outcomes occurred within 6 months of surgery and 64% within 1 year. Five independent predictors of long-term outcome were identified. Three predictors reflected the preexisting chronic disease state: (1) the presence of known vascular disease (hazard ratio, 6.1; 95% confidence interval [CI], 2.5 to 15.0; P less than .0001); (2) a history of congestive heart failure (hazard ratio, 5.0; 95% CI, 2.0 to 12.0; P less than .0005); and (3) known coronary artery disease (hazard ratio, 3.7; 95% CI, 1.7 to 8.0; P less than .0007). Two predictors reflected acute postoperative ischemic events: (1) myocardial infarction/unstable angina (hazard ratio, 20; 95% CI, 7.5 to 53.0; P less than .0001) and (2) myocardial ischemia (hazard ratio, 2.2; 95% CI, 1.1 to 4.3; P less than .03). Patients surviving a postoperative in-hospital myocardial infarction had a 28-fold increase in the rate of subsequent cardiac complications within 6 months following surgery, a 15-fold increase within 1 year, and a 14-fold increase within 2 years (95% CI, 5.8 to 32; P less than .00001). Seventy percent of all long-term adverse outcomes were preceded by in-hospital postoperative ischemia that occurred at least 30 days (median, 282 days) before the long-term event. The development of congestive heart failure or ventricular tachycardia (without ischemia) during hospitalization was not associated with adverse long-term outcome. CONCLUSIONS--The incidence of long-term adverse cardiac outcomes following noncardiac surgery is substantial. At increased risk are patients with chronic cardiovascular disease; at highest risk are patients with acute perioperative ischemic events. We conclude that survivors of in-hospital perioperative ischemic events, specifically myocardial infarction, unstable angina, and postoperative ischemia, warrant more aggressive long-term follow-up and treatment than is currently practiced.     

Elevated cardiac troponins: their significance in acute coronary syndrome and noncardiac conditions

Elevated cardiac troponin I or T levels are caused by cardiac injury. Such elevations in patients with acute coronary syndrome are crucial in terms of diagnosis, risk stratification and guiding therapy. Cardiac troponins are also often elevated in patients with chronic renal failure and in a wide range of other medical conditions in which the pathophysiology of acute coronary syndrome (plaque rupture and thrombosis) is not present. This review discusses the differences between cardiac troponin and other cardiac markers and the importance of bedside testing. The literature on elevated cardiac troponins in patients with acute coronary syndrome, patients without acute coronary syndrome and patients with chronic renal failure is summarized. The significance of elevated cardiac troponins in each group as it relates to prognosis and guiding treatment options is discussed.     

Perioperative anesthetic risk of noncardiac surgery in hypertrophic obstructive cardiomyopathy

To determine their perioperative risk, we reviewed the records of 35 patients with hypertrophic cardiomyopathy diagnosed by cardiac ultrasound and/or catheterization who underwent general (52) or spinal (four) anesthesia--a total of 56 major surgical procedures. There were no operative or related perioperative deaths and no significant ventricular tachyarrhythmias. Intraoperative or postoperative complications included: myocardial infarction with heart failure in one patient who also had coronary artery disease and was one of three patients who had spinal anesthesia, arrhythmia requiring therapy in eight, and angina during supraventricular tachycardia in one. We conclude that the risk of general anesthesia and major noncardiac surgery is low in patients with hypertrophic obstructive cardiomyopathy. Spinal anesthesia, which decreases systemic vascular resistance and increases capacitance, may be relatively contraindicated. Concomitant coronary artery disease may increase the risk.     

老年非心脏手术围手术期的心肌缺血

作者对７０例老年普通外科手术患者围手术期的心肌缺血情况进行分析，结果表明（１）冠心病，高龄（〉７５岁）患者与术中心肌缺血有显著相关性（Ｐ〈０．０５）；（２）术中及术后心动过速（〉１００／ｍｉｎ）、血压升高（收缩压〉２１．３ｋＰａ）与ＳＴ段下降有显著相关性（Ｐ〈０．０５）；（３）牢冠患者围手术期心肌缺血主要表现为无症心状缺血；（４）术后４８ｈ内心肌梗死发生的高危期。     

Antimicrobial vs placebo prophylaxis in noncardiac thoracic surgery.

A prospective, double-blind evaluation of the efficacy and safety of prophylactic cephalosporins was done in 57 patients undergoing noncardiac thoracic surgery. Twenty-eight received cephalosporin therapy, and 29 received placebo. Overall, the incidence of postoperative infections was the same; infections developed in five (17.8%) of the 28 patients in the cephalosporin group and in five (17.2%) of the 29 patients in the placebo group. Of the five deaths attributable to infection, three occurred in patients receiving placebo and two in patients receiving cephalosporin therapy. No differences were noted in WBC counts, fever, duration of hospitalization, hypersensitivity reactions, or abnormal liver functions. However, drug fever, phlebitis, and abnormal renal function occurred more often in the patients receiving cephalosporin therapy.     

Lipid-lowering therapy and in-hospital mortality following major noncardiac surgery

Context  Cardiovascular complications following major noncardiac surgery are an important source of perioperative morbidity and mortality. Although lipid-lowering medications are considered a key component in the primary and secondary prevention of cardiovascular disease, their potential benefit during the perioperative period is uncertain. Objective  To examine the association between treatment with lipid-lowering medications and in-hospital mortality following major noncardiac surgery. Design, Setting, and Patients  A retrospective cohort study based on hospital discharge and pharmacy records of 780 591 patients aged 18 years or older who underwent major noncardiac surgery from January 1, 2000, to December 31, 2001, at any 1 of 329 hospitals throughout the United States. Only patients who survived through at least the second hospital day were included. Lipid-lowering therapy was defined as use during the first 2 hospital days. Propensity matching was used to adjust for numerous baseline differences. Main Outcome Measure  In-hospital mortality. Results  Of the 780 591 patients, 77 082 patients (9.9%) received lipid-lowering therapy perioperatively and 23 100 (2.96%) died during the hospitalization. Treatment with lipid-lowering agents was associated with lower crude mortality (2.13% vs 3.05%, P<.001). In an analysis using matching by propensity score, 1595 patients (2.18%) treated with lipid-lowering medications died compared with 4158 patients (3.15%) who did not receive therapy or in whom treatment was initiated after the second day (P<.001). After adjusting for residual differences in the propensity matched groups using conditional logistic regression, risk of mortality remained lower among treated patients (adjusted odds ratio [OR], 0.62; 95% confidence interval [CI], 0.58-0.67). Based on this adjusted OR, the number needed to treat to prevent a postoperative death in the propensity matched cohort was 85 (95% CI, 77-98) and varied from 186 among patients at lowest risk to 30 among those with a revised cardiac risk index score of 4 or more. In a further analysis using the entire study cohort and adjusting for quintile of propensity, a significant effect of treatment persisted (adjusted OR, 0.71; 95% CI, 0.67-0.75). Conclusions  Treatment with lipid-lowering agents may reduce risk of death following major noncardiac surgery. Clinical trials are required to confirm this observation.      

改良超滤对小儿先天性心脏病术后临床结果影响的系统评价

目的 评价改良超滤对小儿先天性心脏病术后临床结果的影响及其安全性.方法 计算机检索Cochrane图书馆临床对照试验资料库(2009年第2期)、PubMed(1991～2009.4)、EMBASE(1991～2009.4)、VIP(1991～2009.4)、CNKI(1994～2009.4)、CBM(1991～2009.4),文种限制为中文和英文.严格按照纳入和排除标准选择研究,由2人独立对纳入研究进行质量评价,采用RevMan5.0软件进行Meta分析,对不能合并的研究进行描述性分析.结果 纳入9个随机对照试验(RCTs),共587例患儿.结果 显示:改良超滤组和不超滤组相比,改良超滤组患儿术后呼吸机辅助时间短[MD=3.66,95%CI(-6.02,-1.29),P=0.002];和常规超滤组相比,两组患儿术后呼吸机辅助时间相似[MD=-3.21,95%CI(-6.90,0.49),P=0.09];和平衡超滤组相比,两组患儿术后呼吸机辅助时间、重症监护时间及胸腔引流量均相似;改良联合常规或平衡超滤组和常规或平衡超滤组相比,患儿呼吸机辅助时间相似[MD=-2.34,95%CI(-6.74,2.07),P=0.30].重症监护时间[MD=-0.12,95%CI(-0.31,0.06),P=0.19]也相似.所有纳入研究均无超滤相关并发症报道.结论 改良超滤有效减轻了体外循环的不利影响,有利于患儿术后脏器功能的恢复,但当前证据尚未证明该技术的临床结果优于常规超滤或平衡超滤.