The effect of bisoprolol on perioperative mortality and myocardial infarction in high-risk patients undergoing vascular surgery. Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography Study Group

β-blocking agents for surgery: influence on mortality and major outcomes. A meta-analysis

OBJECTIVE

To re-evaluate the effects of perioperative beta-blockade on mortality and major outcomes after surgery.

DESIGN

A meta-analysis of parallel randomized, controlled trials published in English.

SETTING

A university-based electronic search.

PARTICIPANTS

Patients undergoing surgery.

INTERVENTIONS

Two interventions were evaluated: (1) Stopping or continuing a β-blocker in patients on long-term β-blocker therapy; and (2) Adding a β-blocker for the perioperative period.

MEASUREMENTS AND MAIN RESULTS

Stopping a β-blocker before the surgery did not change the risk of myocardial infarction (3 studies including 97 patients): risk ratio (RR), 1.08 (95% confidence interval 0.30, 3.95); I(2), 0%. Adding a β-blocker reduced the risk of death at 1 year: RR, 0.56 (0.31, 0.99); I(2), 0%; p = 0.046; number needed to treat 28 (19, 369) (4 studies with 781 patients). Adding a β-blocker reduced the 0-to-30 day risk of myocardial infarction: RR, 0.65 (0.47, 0.88); I(2), 12.9%; p = 0.006 (15 studies with 12,224 patients), but increased the risk of a stroke: RR, 2.18 (1.40, 3.38); I(2), 0%; p = 0.001 (8 studies with 11,737 patients); number needed to harm 177 (512, 88).

CONCLUSIONS

β-blockers reduced the 1-year risk of death, and this effect seemed greater than the risk of inducing a stroke.

Patients who require non-cardiac surgery in acute coronary syndrome

The coexistence of an acute coronary syndrome (ACS) and non-cardiac surgery (NCS) in an individual patient can be summarized in two challenging clinical scenarios for the treating physician: 1) Post-operative patients who develop ACS and 2) Patients with ACS who subsequently require NCS. Both settings are characterized by a struggle on the part of treating physicians attempting to optimize antithrombotic therapies for ACS while minimizing post-surgical bleeding risk. In this review we address specific clinical issues related to patients with coexistent NCS and ACS, discussing possible management strategies balancing ischemic and bleeding risk in these complex patient scenarios.

β-Adrenergic blockade in cardiovascular disease

The development and subsequent clinical application of the β-adrenergic receptor blocking drugs represent one of the major advances in human pharmacotherapeutics. No other class of synthetic drugs has demonstrated such widespread therapeutic utility for the treatment and prevention of so many cardiovascular diseases. In addition, these drugs have proven to be molecular probes that have contributed to our understanding of the disease, and on the molecular level, both the structure and function of the 7 transmembrane G protein receptors that mediate the actions of many different hormones, neurotransmitters, and drugs. The evolution of β-blocker drug development has led to refinements in their pharmacodynamic actions that include agents with relative β1-selectivity, partial agonist activity, concomitant α-adrenergic blockers activity, and direct vasodilator activity. In addition, long-acting and ultra-short-acting formulations of β-blockers have also demonstrated a remarkable record of clinical safety in patients of all ages.

Safety in the operating theatre--a transition to systems-based care

All surgeons want the best, safest care for their patients, but providing this requires the complex coordination of multiple disciplines to ensure that all elements of care are timely, appropriate, and well organized. Quality-improvement initiatives are beginning to lead to improvements in the quality of care and coordination amongst teams in the operating room. As the population ages and patients present with more complex disease pathology, the demands for efficient systematization will increase. Although evidence suggests that postoperative mortality rates are declining, there is substantial room for improvement. Multiple quality metrics are used as surrogates for safe care, but surgical teams--including surgeons, anaesthetists, and nurses--must think beyond these simple interventions if they are to effectively communicate and coordinate in the face of increasing demands.

[Anesthesia in the surgical repair of thoracoabdominal aneurysms: 17 years experience]

OBJECTIVE

To review the results after thoracoabdominal aortic aneurysms repair performed by the same team of surgeons and anesthesiologists over a 17 year period.

MATERIAL AND METHODS

A prospective and observational study carried out on 65 patients (97% male) who were operated on from 1995 until July 2011 for thoracoabdominal aneurysm, Crawford type i 5 (7.6%), ii 22 (33.8%), iii 17 (26.11%) and iv 21 (32.31%).

RESULTS

The 30-day mortality was 9.2% (6/65 patients), which was the same as the incidence of paraplegia. This complication only occurred in the Crawford types ii and iii aneurysms. Paraplegia was present in 4.5% (1/22) of patients in whom "left bypass" was used, compared with 29% (5/17) in which the intervention was performed by cross-clamping without distal aortic perfusion (P=.068). The most frequent complication was respiratory, with prolonged mechanical ventilation (>48h) in 20% (13 patients) of cases. The mean hospital stay was 28 days (7-92).

DISCUSSION

The average mortality in referral centers is 9.7%, ranging between 5% and 16%. In other centres the mortality at 30 days is between 19% and 31% per year. Our group had a 9.2% of mortality rate at 30 days. The incidence of paraplegia in hospitals with greater experience ranges between 2.7% and 16%. Nowadays, an incidence of less than 10% is accepted as good. We had 9.2%. The use of CSF drainage in these patients, as well as the use of left bypass and moderate hypothermia in the Crawford types i, ii and iii appear to be acceptable for prophylaxis of paraplegia.

[GRADE guidelines: 6. Rating the quality of evidence: imprecision]

GRADE suggests that examination of 95% confidence intervals (CIs) provides the optimal primary approach to decisions regarding imprecision. For practice guidelines, rating down the quality of evidence (i.e., confidence in estimates of effect) is required when clinical action would differ if the upper versus the lower boundary of the CI represented the truth. An exception to this rule occurs when an effect is large, and consideration of CIs alone suggests a robust effect, but the total sample size is not large and the number of events is small. Under these circumstances, one should consider rating down for imprecision. To inform this decision, one can calculate the number of patients required for an adequately powered individual trial (termed the "optimal information size" or OIS). For continuous variables, we suggest a similar process, initially considering the upper and lower limits of the CI, and subsequently calculating an OIS. Systematic reviews require a somewhat different approach. If the 95% CI excludes a relative risk (RR) of 1.0 and the total number of events or patients exceeds the OIS criterion, precision is adequate. If the 95% CI includes appreciable benefit or harm (we suggest a RR of under 0.75 or over 1.25 as a rough guide) rating down for imprecision may be appropriate even if OIS criteria are met.

Critical limb ischemia: advanced medical therapy

Systemic atherosclerosis and its risk factors are present in the majority of patients with critical limb ischemia. Aggressive medical therapy is an immediate and necessary part of the work-up and management of these patients and will involve a multidisciplinary approach. Risk stratification based on a patient's current clinical cardiovascular condition is important in determining the most appropriate and safe intervention and will allow both the patient and physician to make an informed decision regarding risk- and cost-benefits of treatment.

Criteria for Patient Selection and Multidisciplinary Evaluation and Treatment of the Weight Loss Surgery Patient

OBJECTIVE

To provide evidence-based guidelines for patient selection and to recommend the medical and nutritional aspects of multidisciplinary care required to minimize perioperative and postoperative risks in patients with severe obesity who undergo weight loss surgery (WLS).

RESEARCH METHODS AND PROCEDURES

Members of the Multidisciplinary Care Task Group conducted searches of MEDLINE and PubMed for articles related to WLS in general and medical and nutritional care in particular. Pertinent abstracts and literature were reviewed for references. Multiple searches were carried out for various aspects of multidisciplinary care published between 1980 and 2004. A total of 3000 abstracts were identified; 242 were reviewed in detail.

RESULTS

We recommended multidisciplinary screening of WLS patients to ensure appropriate selection; preoperative assessment for cardiovascular, pulmonary, gastrointestinal, endocrine, and other obesity-related diseases associated with increased risk for complications or mortality; preoperative weight loss and cessation of smoking; perioperative prophylaxis for deep vein thrombosis and pulmonary embolism (PE); preoperative and postoperative education and counseling by a registered dietitian; and a well-defined postsurgical diet progression.

DISCUSSION

Obesity-related diseases are often undiagnosed before WLS, putting patients at increased risk for complications and/or early mortality. Multidisciplinary assessment and care to minimize short- and long-term risks include: comprehensive medical screening; appropriate pre-, peri-, and postoperative preparation; collaboration with multiple patient care disciplines (e.g., anesthesiology, pulmonary medicine, cardiology, and psychology); and long-term nutrition education/counseling.

Endovascular aneurysm repair: a perioperative perspective

Endovascular aneurysm repair (EVAR), has surpassed open repair as the technique of choice in many centres in response to several large studies which showed significantly improved 30-day mortality. While several multicentre EVAR trials looked at surgical outcomes, very few have specifically investigated the effect of anaesthetic techniques or perioperative care of these patients. The purpose of this review to is to present some of the current evidence for the different aspects of perioperative management of patients undergoing EVAR. This includes surgical considerations, pre-operative assessment, and choice of anaesthetic technique as well as pharmacological protective strategies.

Postoperative B-type natriuretic Peptide levels associated with prolonged hospitalization in hypertensive patients after non-cardiac surgery

Background and Objectives

B-type natriuretic peptide (BNP) is an important marker for the diagnosis of heart failure and is useful towards predicting morbidity and mortality after non-cardiac surgery. Nevertheless, information on the relationship between postoperative BNP levels and perioperative prognosis after non-cardiac surgery is scarce. The purpose of the study was to assess whether postoperative BNP levels could be used as a predictor of prolonged hospitalization in elderly hypertensive patients after non-cardiac surgery.

Subjects and Methods

Ninety-seven (97) patients, aged 55 years or older (mean age: 73.12±10.05 years, M : F=24 : 73) were enrolled in a prospective study from May 2005 through August 2010. All patients underwent total knee or hip replacement. Postoperative BNP and other diagnostic data were recorded within 24 hours of surgery. Patients that required a prolonged hospital stay due to operative causes, such as wound infection and re-operation, were excluded.

Results

The length of hospital stay was significantly correlated with postoperative BNP levels (p=0.031). Receiver operating characteristic curves demonstrated postoperative BNP levels as predictors of hospital stay ≥30 days with areas under the curve of 0.774 (95% confidence interval: 0.679-0.87, p<0.0001). A BNP cut-off value above 217.5 pg/mL had a sensitivity of 80.6% and a specificity of 66.7% for predicting postoperative hospital stays of 30 days or more.

Conclusion

Postoperative BNP levels may predict the length of hospital stays after non-cardiac surgery in hypertensive patients. Elevated BNP levels were associated with prolonged hospitalization after elective orthopedic surgery.

Influence of hemodynamic variations on the pharmacokinetics of landiolol in patients undergoing cardiovascular surgery

Although landiolol is useful in the emergency management of atrial fibrillation, atrial flutter, and tachycardia, as well as in perioperative arrhythmia control, the influence of hemodynamic changes on the pharmacokinetics of landiolol is unknown. We investigated the influence of hemodynamic variation and the following hepatocirculatory changes after systemic heparinization on the pharmacokinetics of landiolol in patients undergoing cardiovascular surgery under cardiopulmonary bypass. Cardiac output and cardiac index (CI) were continuously monitored in 19 patients using an arterial pressure-based cardiac output monitor. The middle and right hepatic venous blood flow indexes (mHVBFI and rHVBFI) were measured by transesophageal echocardiography, and hemodynamic data were collected at points (T1-T3) as follows: T1, before administration of heparin and after sternotomy; T2, just before systemic heparinization (300 U/kg); T3, 10 min after T2. The plasma concentration of landiolol was measured by HPLC at the same point. After administration of heparin, mean arterial blood pressure, CI, mHVBFI, and rHVBFI were significantly decreased (<0.05). Heart rate was not significantly changed. After systemic heparinization, the landiolol concentration was significantly decreased from 0.407±0.251 µg·mL(-1) to 0.232±0.207 µg·mL(-1) (<0.01). There was no significant difference between T1 and T2 (=0.88). In conclusion, the plasma concentration of landiolol was decreased by diminished CI due to systemic heparinization, but not affected by the change of hepatic blood flow.

Preoperative optimization: rationale and process: is it economic sense?

PURPOSE OF REVIEW

The development of preoperative clinics and the increasing importance of the anaesthetist in the management of surgical risk have expanded the concept of preoperative optimization. This review will focus on the rationale and process for cost-effective preoperative optimization.

RECENT FINDINGS

Postoperative morbidity, rather than mortality, is the most important surgical outcome in economic terms. Since preoperative comorbidity, in association with surgical complexity, is more predictive of hospital costs than the subsequent treatment of postoperative complications per se, preoperative optimization represents an appropriate economic target. Process management, including guidelines to reduce unnecessary investigations and specialist referrals and enhancing perioperative recovery, makes economical sense in the majority of patients who undergo noncardiac surgery with few complications. Preoperative optimization of a minority of high-risk surgical patients is also important given limited critical care resource. However, the evidence for specific optimization strategies in this latter group continues to evolve and requires further clarification in well designed trials.

SUMMARY

The requirement for appropriate methods of risk stratification of surgical patients targeted at the reduction of postoperative morbidity, underpins the development of cost-effective preoperative optimization. Specific process-based and clinical measures may then be applied to the development of individualized perioperative care packages.

The JUPITER trial: myth or reality?

The JUPITER trial is widely hailed as a landmark trial that has the potential to dramatically change the landscape of primary prevention of cardiovascular disease. Like most trials, however, it is not without its limitations. We address some of the common myths and misunderstandings that are underscored by the JUPITER trial. First, by its intentional and ill-advised exclusion of patients with low levels of high-sensitivity C-reactive protein (hsCRP), it is not possible to assess whether baseline hsCRP modifies treatment response to statins or whether it identifies patients most likely to benefit from statin therapy. Second, by stopping the trial early, one cannot rule out the possibility that the treatment benefit was overestimated and risk was underestimated, thereby precluding a reliable estimate of benefit/risk. Finally, as a consequence of early stopping, it is not possible to reliably assess the cost-effectiveness of primary prevention with rosuvastatin. Given these limitations, the attendant societal health policy implications remain largely unknown.

The dangers of stopping a trial too early

To ensure that participants in randomized controlled trials are protected from harm, interim analyses and review of results by an independent data monitoring committee have become standard practice. If an analysis of accumulating data partway through a trial reveals an unanticipated degree of benefit or toxicity, or differences in outcomes between the intervention and control groups are so unimpressive that any prospect of a positive result with the planned sample size is extremely unlikely, investigators may stop the trial earlier than originally scheduled. The practice of stopping randomized controlled trials early is, however, problematic, especially if the trial is stopped for apparent benefit. Concerns in trials stopped early for apparent benefit include appropriate interpretation of results and ethical problems concerning trial participants, clinicians, and society as a whole. In this article, we review the epidemiology of trials stopped early and illustrate some of the problems and controversies associated with stopping randomized controlled trials early for apparent benefit. Finally, we offer guidance for clinicians, those running clinical trials, and authors of systematic reviews.

Clinical evidence, practice guidelines, and β-blocker utilization before major noncardiac surgery

BACKGROUND

Largely on the basis of 2 randomized trials published in the 1990s, β-blockers were initially promoted as an evidence-based intervention for preventing cardiac complications of noncardiac surgery. However, subsequent studies raised concerns about a widespread use of perioperative β-blockade. Little is known regarding how this changing evidence influenced the use of perioperative β-blockers in clinical practice.

METHODS AND RESULTS

We conducted a population-based, time-series analysis (April 1999 to March 2010) among residents of Ontario, Canada (age 66 years and older), to evaluate the influence of research publications and practice guidelines on rates of new β-blocker prescriptions before major elective noncardiac surgery. In an analysis of 249 828 procedures, the rate of new β-blocker prescriptions increased from 26.3 per 1000 procedures in April 1999 to 62.7 per 1000 procedures in the first quarter of 2005, after which it decreased to 19.7 per 1000 procedures by March 2010. We observed a marked decrease in prescriptions (P=0.004) during early 2005, without any preceding publications that raised concerns about perioperative β-blockade. There was no change (P=0.98) in prescription rates after the May 2008 publication of a multicenter, randomized trial that showed increased mortality from perioperative β-blockade. Prescribing trends remain unchanged after revisions of related practice guidelines in 2002 (P=0.28) and 2006 (P=0.53).

CONCLUSIONS

After a period characterized by increasing adoption of preoperative β-blockade between 1999 and 2005, prescriptions rates subsequently fell from 2005 to 2010. Further research is needed to understand the basis for these changes, which are only partially explained by evidence of potential harm.

Preoperative assessment and perioperative management of cardiovascular risk

Preoperative cardiovascular evaluation of patients scheduled to undergo surgery requires a multidisciplinary approach involving anesthetists, surgeons, and cardiologists. Within the last 5 to 10 years, there have been considerable scientific advances in this field, and the European Society of Cardiology (ESC) and the American College of Cardiology/American Heart Association(ACC/AHA) have updated their guidelines.(1,11) Greater emphasis now lies on preoperative clinical risk stratification and less on routine cardiac testing. Prophylactic coronary revascularization is now also seen as rarely indicated simply to lower the risk of surgery.(1) This review will give a brief summary of the guidelines and suggests a practical stepwise approach to evaluate the patient preoperatively.

β-blocker continuation after noncardiac surgery: a report from the surgical care and outcomes assessment program

BACKGROUND

Despite limited evidence of effect, β-blocker continuation has become a national quality improvement metric.

OBJECTIVE

To determine the effect of β-blocker continuation on outcomes in patients undergoing elective noncardiac surgery.

DESIGN, SETTING, AND PATIENTS

The Surgical Care and Outcomes Assessment Program is a Washington quality improvement benchmarking initiative based on clinical data from more than 55 hospitals. Linking Surgical Care and Outcomes Assessment Program data to Washington's hospital admission and vital status registries, we studied patients undergoing elective colorectal and bariatric surgical procedures at 38 hospitals between January 1, 2008, and December 31, 2009.

MAIN OUTCOME MEASURES

Mortality, cardiac events, and the combined adverse event of cardiac events and/or mortality.

RESULTS

Of 8431 patients, 23.5% were taking β-blockers prior to surgery (mean [SD] age, 61.9 [13.7] years; 63.0% were women). Treatment with β-blockers was continued on the day of surgery and during the postoperative period in 66.0% of patients. Continuation of β-blockers both on the day of surgery and postoperatively improved from 57.2% in the first quarter of 2008 to 71.3% in the fourth quarter of 2009 (P value <.001). After adjusting for risk characteristics, failure to continue β-blocker treatment was associated with a nearly 2-fold risk of 90-day combined adverse event (odds ratio, 1.97; 95% CI, 1.19-3.26). The odds were even greater among patients with higher cardiac risk (odds ratio, 5.91; 95% CI, 1.40- 25.00). The odds of combined adverse events continued to be elevated 1 year postoperatively (odds ratio, 1.66; 95% CI, 1.08-2.55).

CONCLUSIONS

β-Blocker continuation on the day of and after surgery was associated with fewer cardiac events and lower 90-day mortality. A focus on β-blocker continuation is a worthwhile quality improvement target and should improve patient outcomes.

Preventive aspects in peripheral artery disease

The prevalence of peripheral artery disease is steadily increasing and is associated with significant morbidity, including a significant percentage of amputations. Peripheral artery disease often goes undiagnosed, making its prevention increasingly important. Patients with peripheral arterial disease are at increased risk of adverse cardiovascular outcomes which makes prevention even more important. Several risk factors have been identified in the pathophysiology of peripheral artery disease which should be modified to decrease risk. Smoking, hyperlipidemia, hypertension, and diabetes are among proven risk factors for the development of peripheral artery disease, thus smoking cessation, lipid control, blood pressure control, and glucose control have been tried and shown to be effective in preventing the morbidity associated with this disease. Pharmacologic agents such as aspirin and clopidogrel alone or in combination have been shown to be effective, though risk of bleeding might be increased with the combination. Anticoagulation use is recommended only for acute embolic cases. Other treatment modalities that have been tried or are under investigation are estrogen replacement, naftidrofuryl, pentoxifylline, hyperbaric oxygen, therapeutic angiogenesis, and advanced glycation inhibitors. The treatment for concomitant vascular diseases does not change in the presence of peripheral artery disease, but aggressive management of risk factors should be undertaken in such cases.

Preoperative cardiac evaluation of the vascular surgery patient--an anesthesia perspective

The morbidity and mortality associated with vascular surgery procedures are largely the results of cardiac events. National guidelines have been regularly proposed and updated by the American College of Cardiology (ACC)/American Heart Association (AHA) to ensure optimal perioperative management and risk stratification. Controversy remains between experts and other cardiology societies regarding several patient care issues including revascularization before surgery, timing of β-blocker therapy, and the administration of antiplatelet therapy. Several landmark articles recently published have helped to modify the guidelines in the hope of improving vascular patient outcomes. In this review, we searched all recent available literature pertaining to perioperative cardiac evaluation before major vascular surgery. We propose an algorithm for preoperative cardiac evaluation, which is a modification to the AHA recommendations. Incorporated in this algorithm are recent published pivotal articles that can help in guiding physicians caring for the vascular patient requiring major operative or endovascular interventions.

Beta-Blocker management in High-Risk Patients Presenting for Non-Cardiac Surgery: Before and after the POISE Trial

The POISE Trial was a randomised, placebo-controlled, double-blind study of the effectiveness of perioperative beta-blockade in preventing cardiac events including death in 8351 patients. Our hypothesis was that knowledge of the results of the POISE Trial would either increase or decrease the use of effective perioperative beta-blockade, depending on the result. Patients presenting for non-cardiac surgery and at risk of perioperative cardiac events were recruited in two cohorts before and after the release of the POISE Trial results. Effective perioperative beta-blockade was defined as heart rate <65 beats per minute for at least 80% of the perioperative period in patients prescribed beta-blockers. Effective perioperative beta-blockade was achieved in 22 (11.5%) of 191 patients prescribed perioperative beta-blockade in the first cohort (n=392) and seven (6%) of 118 patients in the second cohort (n=241) (P=0.10). Effective heart rate control was achieved in 29 (9%) patients prescribed perioperative beta-blockers compared with 10 (3%) patients not prescribed perioperative beta-blockers (P=0.001). The rate of implementation of effective beta-blockade was low before POISE and this did not change significantly after publication. Our finding does not provide reliable evidence of a change in practice as a result of the POISE Trial.

Is it time to translate ischemic preconditioning's mechanism of cardioprotection into clinical practice?

After three decades of intense research on cardioprotection, we still do not have an approved intervention for limiting infarct size in the patient with acute myocardial infarction (AMI) aside from reperfusion therapy. Yet approximately 25% of patients with AMI that are reperfused are still at risk for heart failure because of excessive muscle necrosis. This article will try to make the case that ischemic preconditioning (IPC), still the most potent anti-infarct intervention ever described, is ready for serious clinical testing now. Over the past 25 years, IPC's mechanism has been largely elucidated and targets a reperfusion injury. Ischemic preconditioning was never considered an intervention for AMI because of its need for pretreatment. However, knowledge of IPC's mechanism has revealed a large number of drugs and interventions that will activate IPC's signaling pathway at the time of reperfusion. Several small clinical trials suggest that they can be quite effective, but so far industry seems to have little interest in developing them. So, while basic scientists are in a continuous cycle of discovery and publication for new and novel cardioprotectants, there has been little effort devoted to translating these interventions into clinical practice. We believe that there are suitable IPC-based interventions that are ready for clinical testing today and the time has come for large-scale clinical trials.

Management of postoperative atrial fibrillation

The impact of postoperative atrial fibrillation (PAF) on patient outcomes has prompted intense investigation into the optimal methods for prevention and treatment of this complication. In the prevention of PAF, β-blockers and amiodarone are particularly effective and are recommended by guidelines. However, their use requires caution due to the possibility of drug-related adverse effects. Aside from these risks, perioperative prophylactic treatment with statins seems to be effective for preventing PAF and is associated with a low incidence of adverse effects. PAF can be treated by rhythm control, heart-rate control, and antithrombotic therapy. For the purpose of heart rate control, β-blockers, calcium-channel antagonists, and amiodarone are used. In patients with unstable hemodynamics, cardioversion may be performed for rhythm control. Antithrombotic therapy is used in addition to heart-rate maintenance therapy in cases of PAF >48-h duration or in cases with a history of cerebrovascular thromboembolism. Anticoagulation is the first choice for antithrombotic therapy, and anticoagulation management should focus on maintaining international normalized ratio (INRs) in the 2.0–3.0 range in patients <75 years of age, whereas prothrombin-time INR should be controlled to the 1.6–2.6 range in patients ≥75 years of age. In the future, dabigatran could be used for perioperative management of PAF, because it does not require regular monitoring and has a quick onset of action with short serum half-life. Preventing PAF is an important goal and requires specific perioperative management as well as other approaches. PAF is also associated with lifestyle-related diseases, which emphasizes the ongoing need for appropriate lifestyle management in individual patients.

Reflections on meta-analyses involving trials stopped early for benefit: Is there a problem and if so, what is it?

We review controversies associated with randomized controlled trials (RCTs) stopped early for apparent benefit (truncated RCTs or tRCTs) and present our groups’ perspective. Long-established theory, simulations and recent empirical evidence demonstrate that tRCTs will on average overestimate treatment effects, and this overestimation may be large, particularly when tRCTs have small number of events. Theoretical considerations and simulations demonstrate that on average, meta-analyses of RCTs with appropriate stopping rules will lead to only trivial overestimation of treatment effects. However, tRCTs will disproportionally contribute to meta-analytic estimates when tRCTs occur early in the sequence of trials with few subsequent studies, publication of nontruncated RCTs is delayed, there is publication bias, or tRCTs result in a ‘freezing’ effect in which ‘correcting’ trials are never undertaken. To avoid applying overestimates of effect to clinical decision-making, clinicians should view the results of individual tRCTs with small sample sizes and small number of events with skepticism. Pooled effects from meta-analyses including tRCTs are likely to overestimate effect when there is a substantial difference in effect estimates between the tRCTs and the nontruncated RCTs, and in which the tRCTs have a substantial weight in the meta-analysis despite themselves having a relatively small number of events. Such circumstances call for sensitivity analyses omitting tRCTs.

Genetic variation, β-blockers, and perioperative myocardial infarction

Perioperative myocardial infarction is a common and potentially fatal complication after noncardiac surgery, particular among patients with cardiovascular risk factors. β-blockers have been considered a mainstay in prevention and treatment of perioperative myocardial infarction, yet recent evidence suggests that β-blockers may have an unfavorable risk profile in this setting, and the use has become controversial. What seems conspicuously absent from the current discussion is the appreciation of how much interindividual genetic variation influences the clinical response to β-blocker therapy. Genetic variation in the adrenergic signaling pathway is common, and has a major impact on adrenergic receptor function and β-blocker efficacy in other cardiovascular diseases, such as heart failure and hypertension. Genetic variation in the cytochrome P450 2D6, or CYP2D6, enzyme, which is responsible for the metabolism of most β-blockers, is also important and can lead to poor metabolizing of β-blockers (potential toxicity) or their ultra-rapid degradation (decreased efficacy). Here, we review the molecular, cellular, and physiologic consequences of polymorphisms in the adrenergic signaling pathway and CYP2D6 gene, and show that these are likely relevant factors influencing efficacy, safety, and toxicity of β-blocker therapy in prevention and treatment of perioperative myocardial infarction.

[Cardioprotection]

The demographic change is associated with an increasing number of elderly patients with serious comorbidities. The prevalence of coronary heart disease in particular increases with age and raises the risk of perioperative myocardial ischemia. In the last few years various interventions have been evaluated to lower the perioperative risk for serious cardiovascular events. This includes cardioprotective medical interventions, for example with β-receptor blockers and statins. Current guidelines recommend that patients who are on β-receptor blockers or statins for chronic treatment of cardiovascular diseases should continue this medication throughout the perioperative period. Myocardial conditioning has been assessed to be effective under numerous experimental conditions and clinical trials have also provided evidence for myocardial protection by conditioning. Besides ischemic and anesthetic-induced preconditioning the noninvasive technique of remote preconditioning offers interesting possibilities, especially for patients with serious comorbidities; however, large scale randomized clinical multicentre trials are still needed. Regarding cardioprotective effectiveness, the clinical data for regional anesthesia are very heterogeneous; nevertheless regional anesthesia is very effective in postoperative pain therapy. Therefore regional anesthesia should be used as a part of multimodal therapy concepts to lower the risk of perioperative cardiovascular events.

Risk to and resilience of the coronary heart disease patient during surgery

PURPOSE OF REVIEW

Three topics are at the forefront of the investigation and treatment of patients with coronary artery disease (CAD) undergoing major noncardiac surgery: prophylactic perioperative beta-blockade (PPBB), prophylactic statins and prophylactic preoperative coronary revascularization (PCR). The purpose of the review is to summarize the investigational efforts in each one of these fields and to provide a subjective evaluation as to their impact on perioperative patient care.

RECENT FINDINGS

The data on PPBB are still controversial. Most recent studies are observational with contradicting results on whether PPBB improves perioperative survival and whether chronic beta-blockade is better than beta-blockers added acutely postoperatively. The data on statins are still evolving and the main question remains whether the proven long-term pleiotrophic, plaque-stabilizing effects of statins translate into measurable improvements in hard outcome in the acute, perioperative setting. The data on PCR are also incomplete. The study that previously reported lack of any perioperative benefit to PCR now provides data that in selected patients PCR may nevertheless improve outcome.

SUMMARY

These topics demonstrate how difficult it is to prove a significant change in outcome in high-risk CAD patients by prophylactic preoperative measures and that there is no alternative to clinical judgment and individualized patient care.