The Diabetic Postoperative Mortality and Morbidity (DIPOM) trial: rationale and design of a multicenter, randomized, placebo-controlled, clinical trial of metoprolol for patients with diabetes mellitus who are undergoing major noncardiac surgery

Morbidity and Mortality in Elective Total Hip Arthroplasty Following Surgical Care Improvement Project Guidelines

BACKGROUND

Following evidence questioning the safety and efficacy of perioperative beta-blocker therapy in noncardiac surgery, the Surgical Care Improvement Project (SCIP) guidelines were retired in 2015. However, perioperative myocardial infarctions and cardiac complications remain leading causes of mortality following noncardiac surgery. The impact of the SCIP guidelines on reducing cardiac complications in patients undergoing elective total hip arthroplasty (THA) has not been evaluated.

METHODS

The Nationwide Inpatient Sample was queried for 345,875 elective THA performed from 2003 to 2011. Patient demographics and morbidity as well as the incidence of nonfatal and fatal cardiac complications and overall mortality associated with cardiac complications were determined before and following SCIP implementation.

RESULTS

Following the institution of the SCIP guidelines, the overall mortality following cardiac complications decreased by 41%. Although the incidence of nonfatal cardiac events after THA did increase 5% (primarily secondary to an increased incidence of nonfatal hypotension), the incidence of postoperative inpatient mortality, stroke, fatal hypotension, fatal myocardial infarction, and nonfatal and fatal cardiac arrest significantly decreased.

CONCLUSION

Following the implementation of SCIP guidelines, there was a 41% reduction in mortality and a significant decrease in fatal cardiac complications, postoperative hypotension, myocardial infarction, and cardiac arrest. Despite SCIP guidelines being retired in 2015, evidence supports continuation of perioperative beta-blockade in primary elective total adult hip and knee arthroplasty.

Perioperative β-Blockers in Patients Undergoing Noncardiac Surgery-Scientific Misconduct and Clinical Guidelines

BACKGROUND

β-blocker use in perioperative period of noncardiac surgeries has been a topic of debate since many years. Earlier studies conducted in the 90s showed decreased cardiac adverse events and improved postoperative outcomes with β-blocker use. Based on this, the ACCF and ESC published guidelines strongly supporting β-blocker use. But contemporaneous studies conducted revealed conflicting evidence and have also proven some of the earlier studies to be fraudulent. Although ACCF guidelines have been updated to partially reflect the changes, ESC guidelines continue to support β-blocker use.

AREAS OF UNCERTAINTY

In light of the ACCF and ESC guidelines supporting β-blocker use in perioperative period of noncardiac surgeries, our aim was to review the available literature and consolidate evidence in this regard.

DATA SOURCES

PubMed search was conducted to include relevant studies between 1950 and 2015.

RESULTS

We reviewed 24 eligible studies and few debates conducted in this regard. Based on our review, our findings were as follows: β-blockers should be continued throughout perioperative period in patients who were on β-blockers before surgery for other indications such as angina, hypertension, and symptomatic arrhythmias. Preoperative β-blockers are indicated in patients undergoing high risk vascular surgery or those having high preoperative Cardiac Risk Index Score. In patients with intermediate-to-low cardiac risk, the proven benefit is not sufficient enough to suggest universal use.

CONCLUSIONS

Based on our review, we conclude that the use of β-blockers in perioperative period of noncardiac surgeries should be determined on an individual basis based on risk-benefit analysis. Guideline organizations should update their recommendations based on new evidence.

Morbidity and Mortality in Elective Total Knee Arthroplasty Following Surgical Care Improvement Project Guidelines

BACKGROUND

Perioperative myocardial infarctions and cardiac complications are leading causes of mortality after noncardiac surgery. In an effort to improve patient safety, the Surgical Care Improvement Project (SCIP) implemented guidelines concerning administration of β-blockers therapy aimed to reduce cardiac complications.

METHODS

The Nationwide Inpatient Sample was queried for 759,819 elective total knee arthroplasties performed from 2003 to 2011. Incidence of cardiac complications, mortality, and risk factors for cardiac complications was determined before and after SCIP implementation.

RESULTS

The incidence of cardiac events after total knee arthroplasty remained stable at 9%. The incidence and mortality of postoperative stroke, myocardial infarction, and cardiac arrest significantly decreased. Mortality after cardiac complications decreased by 50%.

CONCLUSION

After the implementation of SCIP guidelines, there was a greater than 50% reduction in mortality and a significant decrease in fatal postoperative stroke, heart failure, and cardiac arrest.

Beta-adrenergic blockers for perioperative cardiac risk reduction in people undergoing vascular surgery

BACKGROUND

People undergoing major vascular surgery have an increased risk of postoperative cardiac complications. Beta-adrenergic blockers represent an important and established pharmacological intervention in the prevention of cardiac complications in people with coronary artery disease. It has been proposed that this class of drugs may reduce the risk of perioperative cardiac complications in people undergoing major non-cardiac vascular surgery.

OBJECTIVES

To review the efficacy and safety of perioperative beta-adrenergic blockade in reducing cardiac or all-cause mortality, myocardial infarction, and other cardiovascular safety outcomes in people undergoing major non-cardiac vascular surgery.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (January 2014) and the Cochrane Central Register of Controlled Trials (CENTRAL; 2013, Issue 12). We searched trials databases and checked reference lists of relevant articles.

SELECTION CRITERIA

We included prospective, randomised controlled trials of perioperative beta-adrenergic blockade of people over 18 years of age undergoing non-cardiac vascular surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection and data extraction. We resolved disagreements through discussion. We performed meta-analysis using a fixed-effect model with odds ratios (ORs) and 95% confidence intervals (CIs).

MAIN RESULTS

We included two studies in this review, both of which were double-blind, randomised controlled trials comparing perioperative beta-adrenergic blockade (metoprolol) with placebo, on cardiovascular outcomes in people undergoing major non-cardiac vascular surgery. We included 599 participants receiving beta-adrenergic blockers (301 participants) or placebo (298 participants). The overall quality of studies was good. However, one study did not report random sequence generation or allocation concealment techniques, indicating possible selection bias, and the other study did not report outcome assessor blinding and was possibly underpowered. It should be noted that several of the outcomes were only reported in a single study and neither of the studies reported on vascular patency/graft occlusion, which reduces the quality of evidence to moderate. There was no evidence that perioperative beta-adrenergic blockade reduced all-cause mortality (OR 0.62, 95% CI 0.03 to 15.02), cardiovascular mortality (OR 0.34, 95% CI 0.01 to 8.32), non-fatal myocardial infarction (OR 0.83, 95% CI 0.46 to 1.49; P value = 0.53), arrhythmia (OR 0.70, 95% CI 0.26 to 1.88), heart failure (OR 1.71, 95% CI 0.40 to 7.23), stroke (OR 2.67, 95% CI 0.11 to 67.08), composite cardiovascular events (OR 0.87, 95% CI 0.55 to 1.39; P value = 0.57) or re-hospitalisation at 30 days (OR 0.86, 95% CI 0.48 to 1.52). However, there was strong evidence that beta-adrenergic blockers increased the odds of intra-operative bradycardia (OR 4.97, 95% CI 3.22 to 7.65; P value < 0.00001) and intra-operative hypotension (OR 1.84, 95% CI 1.31 to 2.59; P value = 0.0005).

AUTHORS' CONCLUSIONS

This meta-analysis currently offers no clear evidence that perioperative beta-adrenergic blockade reduces postoperative cardiac morbidity and mortality in people undergoing major non-cardiac vascular surgery. There is evidence that intra-operative bradycardia and hypotension are more likely in people taking perioperative beta-adrenergic blockers, which should be weighed with any benefit.

Hyperglycemia is associated with lower levels of urokinase-type plasminogen activator and urokinase-type plasminogen activator receptor in wound fluid

AIMS

Wounds in patients with hyperglycemia show impaired healing. Plasminogen activation is crucial in several overlapping phases of wound healing process. In this study, we aimed i) to compare acute wound fluid in patients with hyperglycemia and normoglycemia, ii) to focus on the elements of plasminogen activation in the wound fluid, and iii) to determine if the acute wound fluid characteristics are associated with surgical site infections.

METHODS

In a cohort of 54 patients, a closed suction drain was placed in the wound above the anterior abdominal wall fascia under the skin in order to collect postoperative acute wound fluid samples for 3 following days after colorectal surgery. Patients were classified as normoglycemic (n=25) or hyperglycemic (n=29; 17 with type 2 diabetes and 12 with stress induced hyperglycemia). Surgical site infection was defined according to the Centers for Disease Control criteria. The levels of urokinase-type plasminogen activator (uPA), urokinase-type plasminogen activator receptor (uPAr), plasminogen activator inhibitor-1 (PAI-1), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and fibroblast growth factor-1 (FGF-1) were measured in the wound fluid.

RESULTS

Compared to normoglycemic subjects, patients with hyperglycemia had significantly lower levels of uPA and uPAr in the wound fluid despite similar or even higher circulating levels. There was no significant difference in IL-1β, TNF-α, PAI-1 and FGF-1 levels. In the whole study population, the wound fluid levels of uPA and uPAr were negatively correlated with circulating glucose levels. No difference was detected in the wound fluid characteristics of patients with and without surgical site infection.

CONCLUSION

Patients with hyperglycemia exhibit decreased levels of uPA and uPAr in the wound fluid, suggesting a local failure in plasminogen activation at the wound site.

Treatment recommendations to prevent myocardial ischemia and infarction in patients undergoing vascular surgery

During major vascular surgery (MVS), patients are at high risk for developing unrecognized myocardial infarction (MI) and myocardial ischemia. In reducing postoperative morbidity and mortality, preoperative cardiac risk stratification and adequate medical therapy play a pivotal role. Based on literature and current opinions, medical treatment should comprise at least a combination of beta-blockers, aspirin, and statins. beta-Blockers exert their beneficial effects predominantly through heart rate control, leading to reduced oxygen demand during surgery. A heart rate between 65 and 70 bpm should be achieved. Irrespective of their lipid-lowering effects, statins seem to improve postoperative cardiac outcome by stabilizing coronary artery plaques, thereby preventing atherosclerotic plaque rupture. Aspirin reduces platelet activation and vasoconstriction, thereby limiting ischemic events and reducing nonfatal MI by 34%. Adding clopidogrel to low-dose aspirin might be beneficial toward postoperative cardiac outcomes; however, the effect on the incidence of postoperative bleeding complications may be a problem for future studies to resolve. Whereas beta-blockers inhibit the effect of catecholamines, alpha(2)-agonists inhibit catecholamine release and may be used in the perioperative setting when beta-blockers are contraindicated. Despite the blood pressure-lowering effect and anti-inflammatory properties of angiotensin-converting enzyme inhibitors, the literature does not support their use in patients undergoing MVS. The possible use of calcium antagonists before MVS should be further evaluated in high-risk patients with contraindications to beta-blockers, such as asthma, conduction abnormalities, or a history of stroke. Although nitrates are widely used for treating angina pectoris, the beneficial effect of their use in patients undergoing MVS remains controversial. Therefore, nitrates are not routinely used in the perioperative setting. The current American College of Cardiology/American Heart Association guidelines do not recommend prophylactic coronary revascularization before noncardiac surgery in patients with stable coronary artery disease.

Cardioprotective effects of perioperative β-blockade in vascular surgery patients: fact or fiction?

PURPOSE OF REVIEW

Perioperative β-blockade remains a subject of debate. In this review, recent literature and current guidelines for perioperative β-blockade in vascular surgery patients are discussed.

RECENT FINDINGS

Available evidence suggests that perioperative β-blockade may be beneficial in reducing cardiac events. However, in a recent large study, the incidences of stroke and mortality were increased in patients on perioperative β-blockers. Large systematic reviews failed to demonstrate a net beneficial effect of perioperative β-blockers. The 2009 American and the European guidelines for perioperative β-blockade in vascular surgery disagree on the available evidence but do recommend β-blockade for several indications. Most recent, Wallace and colleagues published a large-sized retrospective study, reporting a beneficial effect of the adoption of a protocol for perioperative β-blockade.

SUMMARY

Perioperative β-blockade reduces cardiac events, but at the expense of increased risk for mortality and stroke. The guidelines seem to be eager to follow positive outcome studies, without considering the effects of β-blockade on other organ systems. Perhaps the main reason for the reported cardioprotective effects of perioperative β-blocker therapy should be sought in failing preoperative β-blocker prophylaxis (irrespective of surgery).

Non-cardiac surgery in developing countries: epidemiological aspects and economical opportunities--the case of Brazil

Background

Worldwide distribution of surgical interventions is unequal. Developed countries account for the majority of surgeries and information about non-cardiac operations in developing countries is scarce. The purpose of our study was to describe the epidemiological data of non-cardiac surgeries performed in Brazil in the last years.

Methods and Findings

This is a retrospective cohort study that investigated the time window from 1995 to 2007. We collected information from DATASUS, a national public health system database. The following variables were studied: number of surgeries, in-hospital expenses, blood transfusion related costs, length of stay and case fatality rates. The results were presented as sum, average and percentage. The trend analysis was performed by linear regression model. There were 32,659,513 non-cardiac surgeries performed in Brazil in thirteen years. An increment of 20.42% was observed in the number of surgeries in this period and nowadays nearly 3 million operations are performed annually. The cost of these procedures has increased tremendously in the last years. The increment of surgical cost was almost 200%. The total expenses related to surgical hospitalizations were more than $10 billion in all these years. The yearly cost of surgical procedures to public health system was more than $1.27 billion for all surgical hospitalizations, and in average, U$445.24 per surgical procedure. The total cost of blood transfusion was near $98 million in all years and annually approximately $10 million were spent in perioperative transfusion. The surgical mortality had an increment of 31.11% in the period. Actually, in 2007, the surgical mortality in Brazil was 1.77%. All the variables had a significant increment along the studied period: r square (r²) = 0.447 for the number of surgeries (P = 0.012), r² = 0.439 for in-hospital expenses (P = 0.014) and r² = 0.907 for surgical mortality (P = 0.0055).

Conclusion

The volume of surgical procedures has increased substantially in Brazil through the past years. The expenditure related to these procedures and its mortality has also increased as the number of operations. Better planning of public health resource and strategies of investment are needed to supply the crescent demand of surgery in Brazil.

Posttreatment but not pretreatment with selective beta-adrenoreceptor 1 antagonists provides neuroprotection in the hippocampus in rats subjected to transient forebrain ischemia

BACKGROUND

beta-Adrenoreceptor antagonists provide neuroprotection against focal cerebral ischemia, but the effects of these antagonists on experimental global cerebral ischemia are unknown. That is, the effect of beta-adrenoreceptor antagonism in vulnerable brain regions after ischemic insult has not been examined. Therefore, we investigated the neuroprotective effects of preischemic or postischemic administration of propranolol (a nonselective beta-adrenoreceptor antagonist), esmolol, and landiolol (selective beta-adrenoreceptor 1 antagonists) against forebrain ischemia in rats.

METHODS

IV administration of saline 10 microL . h(-1), propranolol 100 microg . kg(-1) . min(-1), esmolol 200 microg . kg(-1) . min(-1), or landiolol 50 microg . kg(-1) . min(-1) in male Sprague-Dawley rats was started 30 minutes before or 60 minutes after 8-minute bilateral carotid artery occlusion combined with hypotension (35 mm Hg) under isoflurane (1.5%) anesthesia. All drugs were administered continuously until 5 days after reperfusion, and the animals were evaluated neurologically and histologically after this 5-day period.

RESULTS

Preischemic treatment with propranolol, esmolol, or landiolol failed to provide neuroprotection against forebrain ischemia in the hippocampus. Rats treated with propranolol tended to have a worse score for motor activity and a higher mortality rate (up to 64%), but the differences with other groups were not statistically significant. Postischemic treatment with esmolol and landiolol, but not with propranolol, reduced neuronal injury after forebrain ischemia. However, motor activity did not differ among rats treated postischemically with any of the beta-adrenoreceptor antagonists or saline.

CONCLUSIONS

Postischemic treatment with esmolol and landiolol provided neuroprotection in the hippocampus in rats subjected to bilateral carotid artery occlusion combined with hemorrhagic shock, whereas treatment with propranolol failed to show neuroprotection. We suggest that concomitant beta-blockade and shock might work as a systemic depressant, rather than a neuroprotectant, resulting in exacerbation of cerebral ischemia.

Perioperative use of beta-blockers in the elderly patient

Elderly patients are increasingly referred for complex surgery, but are at particular risk for coronary artery disease. One strategy to prevent perioperative cardiac events in elderly patients is to employ perioperative beta-blockade, but doing so has the potential to increase the incidence of congestive heart failure, perioperative hypotension, bradycardia, and stroke. This article examines common comorbidities in the elderly who may benefit from the chronic use of beta-blockers, prophylactic perioperative use of beta-blockers including timing, dosage, and choice of beta-blocker, the pharmacologic effects of aging, and recommendations on the use of beta-blockers.

Perioperative beta-blocker and statin therapy

PURPOSE OF REVIEW

Perioperative beta-blockade and statin therapy have been advocated to reduce cardiac risk of noncardiac surgery. This review evaluates recent articles published on the cardioprotective effects of perioperative therapy with these medications.

RECENT FINDINGS

Initial studies evaluating beta-blocker therapy during the perioperative period suggested that beta-blockers may be beneficial in reducing cardiac deaths and myocardial infarctions. Later studies and recent meta-analyses, however, are less favorable and suggest that beta-blockers may be associated with increased incidence of bradycardia and hypotension. One randomized trial and several cohort studies have found a significant reduction in cardiovascular complications with perioperative statin therapy. Additionally, statin withdrawal is associated with increased postoperative cardiac risk.

SUMMARY

Based upon the available evidence and guidelines, patients currently taking beta-blockers should continue these agents. Patients undergoing vascular surgery who are at high cardiac risk should also take beta-blockers. The question remains regarding the best protocol to initiate perioperative beta-blockade. Statins should be continued in patients already taking these agents prior to surgery. The optimal duration and time of initiation of statin therapy remains unclear.

Electrical Immunoassays toward Clinical Diagnostics: Identification of Vulnerable Cardiovascular Plaque

A technology for electrical detection of protein biomarkers has been developed. It is based on developing high-density, low-volume multiwell plate devices. The scientific core of this technology lies in integrating nanoporous membranes with microfabricated chip platforms. This results in the conversion of individual pores into wells of picoliter volume. Specific antibodies are localized and isolated into individual wells. The formation of the antibody–antigen-binding complex occurs in individual wells. The membrane allows for robust separation among individual wells.

This technology has the capability to achieve near real-time detection with improved sensitivity and selectivity. This is due to the two factors associated with the technology: (1) event-based electrochemical detection process, where the individual step in the formation of the binding complex results in a specific change to the electrochemical conductance due to the pertubation of the electrical double layer at the base of the each well. (2) The nanoporous membrane is an electrical insulator and is structurally robust throughout hence there is improved signal-to-noise ratio and cross-contamination between is minimized.

Another advantage of this technique is the use of electrical signal in protein identification as compared to the use of optical methods; hence, it is a noninvasive and a label-free technique. The signal acquisition is simple and it uses the existing data acquisition and signal analysis methods.

We have demonstrated the use of this technology for addressing a specific clinical problem: identification of vulnerable coronary plaque in the perioperative state.

Perioperative Management of Patients Undergoing Non-cardiac Vascular Surgery

Patients undergoing non-cardiac vascular surgery have arterial disease affecting more than one vascular bed and commonly have multiple significant co-morbidities. The surgical and anaesthetic teams are asked to address pre-, peri- and postoperative management issues relating not only to the surgery but arising from these co-morbidities. Here we review the strategies and rationale for the optimisation of these high risk patients.

Diabetes mellitus and anesthesia

Diabetes mellitus is an extremely common condition with specific associated comorbidity. Its incidence is rising. Diabetic patients have more perioperative complications than nondiabetic patients. These complications may be related to the presence of organ damage secondary to the diabetes, rather than the defects in carbohydrate metabolism themselves, or to perioperative hyperglycemia. Several new drugs are available for the treatment of diabetes, and these are associated with specific and significant side effects, and varying lengths of action with which the anesthetist should be familiar. Few data are available regarding recommendations for fasting in the presence of these newer drugs. In the postoperative period and during cardiac surgery, hyperglycemia has been shown to be detrimental, and should probably be sought and managed aggressively. The incidence of intraoperative hyperglycemia in noncardiac surgery patients is not as well-defined, nor are the effects of aggressive management.

Ischemic heart disease

Because of changing demographics, increasing numbers of patients with IHD are presenting for noncardiac surgery, and the risks of perioperative morbidity and mortality are significant. The Lee Cardiac Risk Index is applicable in defining perioperative cardiac risk: however, ACC/AHA guidelines may not be applicable comprehensively. The role of biomarkers in risk stratification still needs to be defined. Structured management protocols that help assess, diagnose, and treat patients with IHD preoperatively are likely to help decrease postoperative morbidity and mortality, but clearly are not applicable to all patients. Augmented hemodynamic control with beta-blockers or alpha-2 agonists and modulating inflammation by statins can play an important role in improving outcomes in many patients with IHD; preoperative coronary revascularization may be of limited value. Intraoperative anesthetic management that minimizes hemodynamic perturbations is important; however, the choice of a particular technique typically is not critical. Of critical importance is the postoperative management of the patient. Postoperative myocardial injury should be identified, evaluated, and managed aggressively. Secondary stresses such as sepsis, extubation, and anemia, which can increase demand on the heart, should be treated or minimized. Clearly, optimal care of the patient with IHD entails closely coordinated assessment and management throughout the preoperative, intraoperative, and postoperative phases, if one is to optimize short- and long-term outcomes.

Benefits and harms of perioperative beta-blockade

Cardiac events in patients undergoing surgery may have serious consequences for both short- and long-term postoperative prognosis. Recently conducted trials have not demonstrated beneficial effects of perioperative beta-blockade, although originally small trials with methodological flaws did suggest this. We evaluate the evidence for using perioperative beta-blockade in both cardiac and non-cardiac surgery, and conclude that there is no statistically significant effect on mortality and insufficient evidence for a reduction of the incidence of mycocardial infarction in meta-analyses of all randomized trials. However, confidence intervals of the intervention effects in the meta-analyses are wide, leaving room for both benefits and harms. The largest observational study performed suggests that perioperative beta-blockade is associated with higher mortality in patients with low cardiac risk or diabetes, and with lower mortality in patients with high cardiac risk undergoing non-cardiac surgery. Larger randomized trials are needed to determine dosage, optimal duration, and safety of therapy, and to identify populations in whom-and how-perioperative beta-blockade may be beneficial.

Rationale, design, and organization of the PeriOperative ISchemic Evaluation (POISE) trial: a randomized controlled trial of metoprolol versus placebo in patients undergoing noncardiac surgery

BACKGROUND

Noncardiac surgery is associated with significant cardiovascular mortality, morbidity, and cost. Small trials of beta-blockers suggest that they may prevent cardiovascular events in patients undergoing noncardiac surgery, but trial results are inconclusive. We have initiated the POISE trial to definitively establish the effects of beta-blocker therapy in patients undergoing noncardiac surgery.

METHODS

The POISE trial is a blinded, randomized, and controlled trial of controlled-release metoprolol versus placebo in 10000 patients at risk for a perioperative cardiovascular event who are undergoing noncardiac surgery. Patients will receive the study drug 2 to 4 hours before surgery and subsequently for 30 days. The primary outcome is a composite of cardiovascular death, nonfatal myocardial infarction, and nonfatal cardiac arrest at 30 days. Patients will also be followed for events at 1 year.

RESULTS

To date, the POISE trial has recruited >6300 patients in 182 centers in 21 countries. Currently, the patients' mean age is 69 years; 63% are males, 43% have a history of coronary artery disease, 43% have a history of peripheral arterial disease, and 30% have diabetes. Most participants have undergone vascular (42%), intraabdominal (23%), or orthopedic (19%) surgery.

CONCLUSIONS

The POISE trial is a large international trial that will provide a reliable assessment of the effects of beta-blocker therapy in patients undergoing noncardiac surgery.

Effect of perioperative beta blockade in patients with diabetes undergoing major non-cardiac surgery: randomised placebo controlled, blinded multicentre trial

OBJECTIVES

To evaluate the long term effects of perioperative beta blockade on mortality and cardiac morbidity in patients with diabetes undergoing major non-cardiac surgery.

DESIGN

Randomised placebo controlled and blinded multicentre trial. Analyses were by intention to treat.

SETTING

University anaesthesia and surgical centres and one coordinating centre.

PARTICIPANTS

921 patients aged > 39 scheduled for major non-cardiac surgery.

INTERVENTIONS

100 mg metoprolol controlled and extended release or placebo administered from the day before surgery to a maximum of eight perioperative days.

MAIN OUTCOME MEASURES

The composite primary outcome measure was time to all cause mortality, acute myocardial infarction, unstable angina, or congestive heart failure. Secondary outcome measures were time to all cause mortality, cardiac mortality, and non-fatal cardiac morbidity.

RESULTS

Mean duration of intervention was 4.6 days in the metoprolol group and 4.9 days in the placebo group. Metoprolol significantly reduced the mean heart rate by 11% (95% confidence interval 9% to 13%) and mean blood pressure by 3% (1% to 5%). The primary outcome occurred in 99 of 462 patients in the metoprolol group (21%) and 93 of 459 patients in the placebo group (20%) (hazard ratio 1.06, 0.80 to 1.41) during a median follow-up of 18 months (range 6-30). All cause mortality was 16% (74/462) in the metoprolol group and 16% (72/459) in the placebo group (1.03, 0.74 to 1.42). The difference in risk for the proportion of patients with serious adverse events was 2.4% (- 0.8% to 5.6%).

CONCLUSIONS

Perioperative metoprolol did not significantly affect mortality and cardiac morbidity in these patients with diabetes. Confidence intervals, however, were wide, and the issue needs reassessment.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN58485613.

Lack of adherence with preoperative B-blocker recommendations in a multicenter study

BACKGROUND

Clinical guidelines support the use of preoperative B-blocker in select patients. Patient safety groups have sought to measure the level of adherence to these recommendations.

OBJECTIVE

This study was performed to compare the utilization of preoperative B-blocker with current guidelines across multiple diverse institutions.

DESIGN

Retrospective chart review was performed of inpatients undergoing noncardiac surgery across 5 hospital centers during 2003 to 2004. The primary outcome of interest was the administration of preoperative B-blocker.

PARTICIPANTS

The study sample included 1,304 randomly selected patients meeting the guideline criteria for preoperative B-blockade.

MEASUREMENTS AND MAIN RESULTS

Among patients meeting recommendations for preoperative B-blocker, only 44% (430/983) received B-blocker before surgery. Patients who had not previously received B-blocker were given B-blocker before surgery in only 14% (85/600) of cases. Target heart rates goals for perioperative B-blockade were achieved in 26% (113/430) of cases. Predictors for initiating preoperative B-blocker included nonelective surgery or a history of hypertension or diabetes. Individual hospitals were independently predictive of preoperative B-blocker administration in multivariable models.

CONCLUSIONS

Preoperative B-blocker was significantly underutilized when compared with the current guideline recommendations. Target heart rate goals were not achieved in clinical practice, and few hospitalized patients had preoperative B-blockade initiated. The lack of adherence to preoperative B-blocker recommendations in practice may be impacted by ongoing clinical questions regarding the appropriate selection of candidates for this therapy. Further efforts toward achieving guideline recommendations for preoperative B-blocker use should be focused on the subset of patients that are uniformly agreed upon to be at high risk for cardiac events.

Beta-blockade in the perioperative period: where do we stand after all the trials?

Perioperative myocardial infarction following noncardiac surgery is a complex process with a variety of proposed etiologic factors. Perioperative beta-blockade has been reported to reduce perioperative myocardial infarction and cardiac death, with possible direct effects on longer-term outcome, particularly after vascular surgery. Despite two high-profile studies that have pushed this topic into the mainstream of medicine, the number of patients studied and outcomes observed remains limited, especially for a therapy recommended for widespread adoption in millions of patients globally. Observational analyses, small meta-analyses, and newer randomized trial data (primarily in abstract format) suggest the therapy is of benefit in high-risk patients, whereas in patients at intermediate or low risk, it is either mildly efficacious or neutral in effect. Adverse effects appear to be limited to the expected primary hemodynamic side effects of bradycardia and hypotension, although a suggestion of increased mortality has been reported in one observational analysis in the lowest-risk group. beta-Blockade may be associated with reduction in length of stay and reduced analgesic requirements, although these effects remain controversial. A single mega-trial being conducted outside of the United States with a target goal of 10,000 patients is ongoing and promises to provide definitive data within the next few years. Ongoing research into various etiologies of perioperative myocardial infarction and other medications with potential efficacy in this setting, including the important antiplatelet agents, must also be considered in developing recommendations for widespread adoption of perioperative beta-blockade.

[Preoperative cardiac assessment using dobutamine stress echocardiography]

Postoperative myocardial ischaemia is the leading cause of life expectancy impairment after high cardiac risk surgical procedures. Preoperative identification of patients at high risk for such complication helps reducing its postoperative incidence through therapeutic adjustments. The former relies upon preoperative selection of patients who are candidates for cardiac testing using dobutamine stress echocardiography, according to ACC/AHA guidelines. This exam evaluates echographic myocardial response to a pharmacological stress induced by dobutamine infusion. Its aim is to reproduce part of the stress the myocardium will undergo during surgical procedure. A stress induced myocardial ischaemia suggests such a complication could occur postoperatively. A positive dobutamine stress echocardiography justifies to prescribe preoperative anti-ischaemic treatment in order to reduce the cardiac risk of the further surgical procedure. Moreover, it justifies clear definition of perioperative haemodynamic objectives. Whatever the result of the dobutamine stress echocardiography, cardiac ischaemia should be monitored up to the third postoperative day on the basis of a daily 12-lead electrocardiogram recording and daily plasmatic troponin Ic measurement.

Avaliação de dislipidemia e de índices antropométricos em pacientes com Diabetes Mellitus tipo 1

A intensificação do tratamento insulínico no Diabetes Mellitus tipo 1 (DM1) tem resultado na melhora do seu controle clínico e metabólico, entretanto com aumento da prevalência de sobrepeso e obesidade, o que contribuiria para um maior risco cardiovascular. O objetivo deste estudo foi avaliar os fatores demográficos, clínicos e laboratoriais associados à presença de dislipidemia em uma população de pacientes com DM1 comparada a uma população não diabética. Estudamos 72 pacientes com DM1, sendo 52,8% do sexo feminino, com idade de 22,7 ± 9,6 anos e índice de massa corporal (IMC) de 21,1 ± 3,1Kg/m², e 66 pacientes não diabéticos, sendo 60,6% do sexo feminino, com idade de 23,1 ± 10,9 anos e IMC de 22,1 ± 3,7Kg/m². A amostra incluía 13 crianças, sendo 6 com DM1, 47 adolescentes, sendo 23 com DM1, e 78 adultos, sendo 43 com DM1. Observamos na população adulta de pacientes com DM1 menor apoB (p< 0,01), maior índice apoA/apoB (p< 0,01) e menor sobrepeso (p= 0,04) em relação à população não diabética, não sendo encontrada diferença no perfil lipídico entre essas populações. As crianças e adolescentes diabéticas apresentaram maior prevalência de colesterol total alterado (p= 0,02 e p< 0,01, respectivamente) e LDL-colesterol alterado (p= 0,02 e p= 0,01, respectivamente) em comparação às crianças e adolescentes não DM. Concluímos que os métodos usualmente utilizados na rotina de atendimento ambulatorial de pacientes com DM1 não são capazes de identificar as alterações lipídicas que poderiam ser indicativas do maior risco cardiovascular nestes pacientes, principalmente no que diz respeito à população adulta.

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., beta-blockers, alpha2-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.

A meta-analysis of perioperative beta blockade: What is the actual risk reduction?

BACKGROUND

The use of beta blockers in surgical patients has been suggested to decrease perioperative cardiac events. However, the overall risk reduction, on the basis of solely aggregate data from randomized studies, is unknown. The objective is to evaluate the effect of perioperative beta blockade in noncardiac surgery for protection against mortality or cardiac events.

METHODS

We performed a formal meta-analysis. The Medline database was searched for articles published from 1966-2004 by using the terms perioperative, beta blocker, surgery, and noncardiac. Inclusion criteria were randomized controlled trials evaluating perioperative beta blockade in noncardiac surgery. Studies were evaluated independently by 2 researchers. Cochrane Collaboration Software (Review Manager 4.2) was used to calculate relative risk (RR), risk difference (RD), and 95% confidence interval (CI). Six distinct postoperative adverse events were analyzed.

RESULTS

Eligible studies included 6 randomized controlled trials evaluating perioperative beta blockade in patients undergoing noncardiac surgery. These studies evaluated a total of 632 patients: 354 received perioperative beta blockade and 278 did not. Results for the 6 postoperative outcomes are shown. [table: see text] The 2 largest effects were a decrease in long-term cardiac mortality from 12% to 2% and a decrease in myocardial ischemia from 33% to 15%. All outcomes except perioperative overall mortality had improvements (P < .02), which favor the use of perioperative beta blockade.

CONCLUSIONS

This report highlights for the first time the aggregated risk reduction from all published randomized controlled trials, and shows the protection of perioperative beta blockade against both short-term complications and mortality.

Perioperative beta-blocker therapy and mortality after major noncardiac surgery

BACKGROUND

Despite limited evidence from randomized trials, perioperative treatment with beta-blockers is now widely advocated. We assessed the use of perioperative beta-blockers and their association with in-hospital mortality in routine clinical practice.

METHODS

We conducted a retrospective cohort study of patients 18 years of age or older who underwent major noncardiac surgery in 2000 and 2001 at 329 hospitals throughout the United States. We used propensity-score matching to adjust for differences between patients who received perioperative beta-blockers and those who did not receive such therapy and compared in-hospital mortality using multivariable logistic modeling.

RESULTS

Of 782,969 patients, 663,635 (85 percent) had no recorded contraindications to beta-blockers, 122,338 of whom (18 percent) received such treatment during the first two hospital days, including 14 percent of patients with a Revised Cardiac Risk Index (RCRI) score of 0 and 44 percent with a score of 4 or higher. The relationship between perioperative beta-blocker treatment and the risk of death varied directly with cardiac risk; among the 580,665 patients with an RCRI score of 0 or 1, treatment was associated with no benefit and possible harm, whereas among the patients with an RCRI score of 2, 3, or 4 or more, the adjusted odds ratios for death in the hospital were 0.88 (95 percent confidence interval, 0.80 to 0.98), 0.71 (95 percent confidence interval, 0.63 to 0.80), and 0.58 (95 percent confidence interval, 0.50 to 0.67), respectively.

CONCLUSIONS

Perioperative beta-blocker therapy is associated with a reduced risk of in-hospital death among high-risk, but not low-risk, patients undergoing major noncardiac surgery. Patient safety may be enhanced by increasing the use of beta-blockers in high-risk patients.

The effects of a randomised multi‐centre trial and international accreditation on availability and quality of clinical guidelines

PURPOSE

To examine the availability and quality of clinical guidelines on perioperative diabetes care in hospital units before and after a randomised clinical trial (RCT) and international accreditation.

DESIGN/METHODOLOGY/APPROACH

Interventional "before-after" study in 51 units (38 surgical and 13 anaesthetic) in nine hospitals participating in a RCT in the greater Copenhagen area; 27 of the units also underwent international accreditation.

FINDINGS

The proportion of units with guidelines increased from 24/51 (47 percent) units before to 38/51 (75 percent) units after the trial. Among the 27 units without guidelines before the trial, significantly more accredited units compared to non-accredited units had a guideline after the trial (9/10 (90 percent) compared to 5/17 (29 percent). The quality of the systematic development scale and the clinical scales improved significantly after the trial in both accredited units (both p < 0.001) and in non-accredited units (both p < 0.02). The improvement of the systematic development scale was significantly higher in accredited than in non-accredited units (p < 0.01).

ORIGINALITY/VALUE

The combination of conducting both the DIPOM Trial and international accreditation led to a significant improvement of both dissemination and quality of guidelines on perioperative diabetic care.