Meta-analysis of secure randomised controlled trials of β-blockade to prevent perioperative death in non-cardiac surgery

Difficulty in detecting discrepancies in a clinical trial report: 260-reader evaluation

Background: Scientific literature can contain errors. Discrepancies, defined as two or more statements or results that cannot both be true, may be a signal of problems with a trial report. In this study, we report how many discrepancies are detected by a large panel of readers examining a trial report containing a large number of discrepancies.

Methods: We approached a convenience sample of 343 journal readers in seven countries, and invited them in person to participate in a study. They were asked to examine the tables and figures of one published article for discrepancies. 260 participants agreed, ranging from medical students to professors. The discrepancies they identified were tabulated and counted. There were 39 different discrepancies identified. We evaluated the probability of discrepancy identification, and whether more time spent or greater participant experience as academic authors improved the ability to detect discrepancies.

Results: Overall, 95.3% of discrepancies were missed. Most participants (62%) were unable to find any discrepancies. Only 11.5% noticed more than 10% of the discrepancies. More discrepancies were noted by participants who spent more time on the task (Spearman’s ρ = 0.22, P < 0.01), and those with more experience of publishing papers (Spearman’s ρ = 0.13 with number of publications, P = 0.04).

Conclusions: Noticing discrepancies is difficult. Most readers miss most discrepancies even when asked specifically to look for them. The probability of a discrepancy evading an individual sensitized reader is 95%, making it important that, when problems are identified after publication, readers are able to communicate with each other. When made aware of discrepancies, the majority of readers support editorial action to correct the scientific record.

[Catecholamines: pro and contra]

BACKGROUND

Catecholamines with vasopressor and inotropic effects are commonly used in intensive care medicine. The aim of this review is to explain some of the physiologic actions on which a catecholamine therapy is based, but also to elucidate the risks which are associated with an uncritical and excessive use of these drugs.

SIDE EFFECTS

Emphasis is placed on the myocardial damage triggered by adrenergic overstimulation. There is considerable evidence that in conditions of severe heart failure, myocardial ischemia as well as cardiogenic and septic shock especially the use of catecholamines with predominant β-adrenergic effects (epinephrine, dobutamine, dopamine) can have a negative clinical impact. A simple cardiac risk marker might be a tachycardia.

ADMINISTRATION

Vasopressor therapy with norepinephrine, based on individually applied perfusion parameters (e.g., urine output, lactate), however, seems justified in many conditions of shock and hemodynamic instability during deep analgosedation. In terms of a cardioprotective therapy, the administration of catecholamines, however, should always be reevaluated and titrated to the minimum deemed necessary.

Optimal medical therapy improves clinical outcomes in patients undergoing revascularization with percutaneous coronary intervention or coronary artery bypass grafting: insights from the Synergy Between Percutaneous Coronary Intervention with TAXUS and Cardiac Surgery (SYNTAX) trial at the 5-year follow-up

BACKGROUND

There is a paucity of data on the use of optimal medical therapy (OMT) in patients with complex coronary artery disease undergoing revascularization with percutaneous coronary intervention or coronary artery bypass grafting (CABG) and its long-term prognostic significance.

METHODS AND RESULTS

The Synergy Between Percutaneous Coronary Intervention With TAXUS and Cardiac Surgery (SYNTAX) trial is a multicenter, randomized, clinical trial of patients (n=1800) with complex coronary disease randomized to revascularization with percutaneous coronary intervention or CABG. Detailed drug history was collected for all patients at discharge and at the 1-month, 6-month, 1-year, 3-year, and 5-year follow-ups. OMT was defined as the combination of at least 1 antiplatelet drug, statin, β-blocker, and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker. Five-year clinical outcomes were stratified by OMT and non-OMT. OMT was underused in patients treated with coronary revascularization, especially CABG. OMT was an independent predictor of survival. OMT was associated with a significant reduction in mortality (hazard ratio, 0.64; 95% confidence interval, 0.48-0.85; P=0.002) and composite end point of death/myocardial infarction/stroke (hazard ratio, 0.73; 95% confidence interval, 0.58-0.92; P=0.007) at the 5-year follow-up. The treatment effect with OMT (36% relative reduction in mortality over 5 years) was greater than the treatment effect of revascularization strategy (26% relative reduction in mortality with CABG versus percutaneous coronary intervention over 5 years). On stratified analysis, all the components of OMT were important for reducing adverse outcomes regardless of revascularization strategy.

CONCLUSIONS

The use of OMT remains low in patients with complex coronary disease requiring coronary intervention with percutaneous coronary intervention and even lower in patients treated with CABG. Lack of OMT is associated with adverse clinical outcomes. Targeted strategies to improve OMT use in postrevascularization patients are warranted.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00114972.

The Effect of beta-blockade on objectively measured physical fitness in patients with abdominal aortic aneurysms--A blinded interventional study

BACKGROUND

Perioperative beta-blockade is widely used, especially before vascular surgery; however, its impact on exercise performance assessed using cardiopulmonary exercise testing (CPET) in this group is unknown. We hypothesized that beta-blocker therapy would significantly improve CPET-derived physical fitness in this group.

METHODS

We recruited patients with abdominal aortic aneurysms (AAA) of <5.5 cm under surveillance. All patients underwent CPET on and off beta-blockers. Patients routinely prescribed beta-blockers underwent a first CPET on medication. Beta-blockers were stopped for one week before a second CPET. Patients not routinely taking beta-blockers underwent the first CPET off treatment, then performed a second CPET after commencement of bisoprolol for at least 48 h. Oxygen uptake (.VO2) at estimated lactate threshold and .VO2 at peak were primary outcome variables. A linear mixed-effects model was fitted to investigate any difference in adjusted CPET variables on and off beta-blockers.

RESULTS

Forty-eight patients completed the study. No difference was observed in .VO2 at estimated lactate threshold and .VO2 at peak; however, a significant decrease in .VE/.VCO2 at estimated lactate threshold and peak, an increase in workload at estimated lactate threshold., O2 pulse and heart rate both at estimated lactate threshold and peak was found with beta-blockers. Patients taking beta-blockers routinely (chronic group) had worse exercise performance (lower .VO2 ).

CONCLUSIONS

Beta blockade has a significant impact on CPET-derived exercise performance, albeit without changing .VO2 at estimated lactate threshold and.VO2 at peak. This supports performance of preoperative CPET on or off beta-blockers depending on local perioperative practice.

CLINICAL TRIAL REGISTRATION

NCT 02106286.

Preoperative optimization and risk assessment

Because most older adults with hip fractures require urgent surgical intervention, the preoperative medical evaluation focuses on the exclusion of the small number of contraindications to surgery, and rapid optimization of patients for operative repair. Although many geriatric fracture patients have significant chronic medical comorbidities, most patients can be safely stabilized for surgery with medical and orthopedic comanagement by anticipating a small number of common physiologic responses and perioperative complications. In addition to estimating perioperative risk, the team should focus on intravascular volume restoration, pain control, and avoidance of perioperative hypotension.

Perioperative cardiovascular medicine: an update of the literature 2013-2014

Perioperative medicine is an important and rapidly expanding area of interest across multiple specialties, including internal medicine, anesthesiology, surgery, cardiology, and hospital medicine. A multispecialty team approach that ensures the best possible patient outcomes has fostered collaborative strategies across the continuum of patient care. Staying current in this multidisciplinary field is difficult, because physicians interested in perioperative medicine would need to review multiple specialty journals on a regular basis. To facilitate this process, the authors performed a focused review of this literature published in 2013 and early 2014. In this update, key articles are reviewed that potentially impact clinical practice in perioperative cardiovascular risk prediction and risk management.

Perioperative beta-blockade: might the baby go out with the bath water?

Perioperative β-blocker therapy has been advocated to reduce cardiac mortality and morbidity in high-risk cardiac patients undergoing non-cardiac surgery. Core data that supported this intervention and informed international societal guidelines has recently been withdrawn. A subsequent meta-analysis of the remaining data reporting excess mortality has re-opened the debate about the utility of β-blocker therapy in the perioperative period. Criticism of remaining trial designs and new insights into the protective mechanisms of β-blocker therapy in critical illness raise important questions that should now be addressed by a further robust, high-quality randomised control trial.

Learning from mistakes in clinical practice guidelines: the case of perioperative β-blockade

For more than two decades, the role of beta-blockers in preventing cardiac complications after major surgery has been the subject of contentious scientific and policy debate. Based on two small but highly publicized randomized trials published in 1996 and 1999, prominent U.S. organizations embraced preoperative beta-blocker initiation as a “best practice” and an opportunity for widespread safety improvement. Yet only a few years later, expert recommendations regarding preoperative beta-blockers were revised and downgraded when subsequent research failed confirm promising early findings and called attention to potential harms associated with beta-blocker overuse. In this paper, we trace the history of preoperative beta-blocker recommendations as a case study in lessons to be learned from reversals of guideline recommendations based initially on evidence drawn from randomized, controlled trials. Ultimately, we find that the policy significance that stakeholders ascribed to early beta-blocker studies combined with the prestige that experts assigned to the randomized controlled trial as a form of evidence to short-circuit discourse on the risks of preoperative beta-blocker initiation and led it to be elevated prematurely as a best practice. As such, the story of preoperative beta-blockers illustrates threats to objectivity in guidelines that can emerge from policy imperatives that lend primacy to the rapid translation of research into practice and from perspectives that unduly emphasize the strengths of randomized trials.

A case of above knee amputation with preoperative high risks

An 85-year-old malnourished man was admitted with ischemia-induced necrosis of the right leg and high-risk factors, including chronic obstructive pulmonary disease, pneumonia, and infection of the necrotic leg. We controlled the infection and provided proper nutrition. Using light general anesthesia and a nerve block, we amputated the leg above the knee. The patient could eat and drink the same day following the surgery, and respiratory rehabilitation was begun the next day. His postoperative course was uneventful. Our case suggests that maintenance of good nutrition may play a key role for high-risk elders undergoing leg amputation.

Exclusion of 'nonRCT evidence' in guidelines for chronic diseases - is it always appropriate? The Look AHEAD study

Evidence-based medicine (EBM) is the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients. The introduction of EBM was a conceptual and practical milestone in the history of medicine, with far-reaching impact yet to be fully realized. EBM has limitations, including inapplicability to populations dissimilar to those in studies, and may not reflect duration of exposure to risk factors, details of lifestyle, incubation period, latency, or environmental changes during chronic diseases. Routine exclusion of evidence other than randomized controlled trials (RCTs) or meta-analyses from consideration in treatment may not always be wise. This review is not a result of a search, but rather a conceptual unification of (a) the increasing restrictions in guideline-writing favoring more RCTs, and rejecting observational studies when chronic diseases with a long incubation period may sometimes be best probed by the latter; (b) the possibility RCTs may be inconclusive, nonapplicable, or result in 'negative' results which may misdirect future therapy by physicians and undermine adherence by patients; (c) the potential improvement in patient care from having all available information evaluated (especially epidemiological studies of chronic diseases) and synthesized in guidelines. The example of the Look AHEAD study is chosen - a 'negative' RCT with significant information overlooked by reviewers, who initially declared that weight loss and physical activity were ineffective in treating diabetes, or in preventing cardiovascular complications. In this review, placing this study in perspective, among others, suggests the opposite - exercise and weight loss are effective if done early and sufficiently. Synthesizing worthy data from many sources, including prospective and pathophysiological studies, particularly when RCTs are unavailable, has the potential to add depth and expand the understanding of disease. In addition, integrated data may generate useful, rich material for use during shared decision making discussions with patients, and clarify future hypotheses.

Perioperative beta-blockers for preventing surgery-related mortality and morbidity

BACKGROUND

Randomized controlled trials have yielded conflicting results regarding the ability of beta-blockers to influence perioperative cardiovascular morbidity and mortality. Thus routine prescription of these drugs in unselected patients remains a controversial issue.

OBJECTIVES

The objective of this review was to systematically analyse the effects of perioperatively administered beta-blockers for prevention of surgery-related mortality and morbidity in patients undergoing any type of surgery while under general anaesthesia.

SEARCH METHODS

We identified trials by searching the following databases from the date of their inception until June 2013: MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), Biosis Previews, CAB Abstracts, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Derwent Drug File, Science Citation Index Expanded, Life Sciences Collection, Global Health and PASCAL. In addition, we searched online resources to identify grey literature.

SELECTION CRITERIA

We included randomized controlled trials if participants were randomly assigned to a beta-blocker group or a control group (standard care or placebo). Surgery (any type) had to be performed with all or at least a significant proportion of participants under general anaesthesia.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data from all studies. In cases of disagreement, we reassessed the respective studies to reach consensus. We computed summary estimates in the absence of significant clinical heterogeneity. Risk ratios (RRs) were used for dichotomous outcomes, and mean differences (MDs) were used for continuous outcomes. We performed subgroup analyses for various potential effect modifiers.

MAIN RESULTS

We included 89 randomized controlled trials with 19,211 participants. Six studies (7%) met the highest methodological quality criteria (studies with overall low risk of bias: adequate sequence generation, adequate allocation concealment, double/triple-blinded design with a placebo group, intention-to-treat analysis), whereas in the remaining trials, some form of bias was present or could not be definitively excluded (studies with overall unclear or high risk of bias). Outcomes were evaluated separately for cardiac and non-cardiac surgery. CARDIAC SURGERY (53 trials)We found no clear evidence of an effect of beta-blockers on the following outcomes.• All-cause mortality: RR 0.73, 95% CI 0.35 to 1.52, 3783 participants, moderate quality of evidence.• Acute myocardial infarction (AMI): RR 1.04, 95% CI 0.71 to 1.51, 3553 participants, moderate quality of evidence.• Myocardial ischaemia: RR 0.51, 95% CI 0.25 to 1.05, 166 participants, low quality of evidence.• Cerebrovascular events: RR 1.52, 95% CI 0.58 to 4.02, 1400 participants, low quality of evidence.• Hypotension: RR 1.54, 95% CI 0.67 to 3.51, 558 participants, low quality of evidence.• Bradycardia: RR 1.61, 95% CI 0.97 to 2.66, 660 participants, low quality of evidence.• Congestive heart failure: RR 0.22, 95% CI 0.04 to 1.34, 311 participants, low quality of evidence.Beta-blockers significantly reduced the occurrence of the following endpoints.• Ventricular arrhythmias: RR 0.37, 95% CI 0.24 to 0.58, number needed to treat for an additional beneficial outcome (NNTB) 29, 2292 participants, moderate quality of evidence.• Supraventricular arrhythmias: RR 0.44, 95% CI 0.36 to 0.53, NNTB six, 6420 participants, high quality of evidence.• On average, beta-blockers reduced length of hospital stay by 0.54 days (95% CI -0.90 to -0.19, 2450 participants, low quality of evidence). NON-CARDIAC SURGERY (36 trials)We found a potential increase in the occurrence of the following outcomes with the use of beta-blockers.• All-cause mortality: RR 1.24, 95% CI 0.99 to 1.54, 11,463 participants, low quality of evidence.Whereas no clear evidence of an effect was noted when all studies were analysed, restricting the meta-analysis to low risk of bias studies revealed a significant increase in all-cause mortality with the use of beta-blockers: RR 1.27, 95% CI 1.01 to 1.59, number needed to treat for an additional harmful outcome (NNTH) 189, 10,845 participants.• Cerebrovascular events: RR 1.59, 95% CI 0.93 to 2.71, 9150 participants, low quality of evidence.Whereas no clear evidence of an effect was found when all studies were analysed, restricting the meta-analysis to low risk of bias studies revealed a significant increase in cerebrovascular events with the use of beta-blockers: RR 2.09, 95% CI 1.14 to 3.82, NNTH 255, 8648 participants.Beta-blockers significantly reduced the occurrence of the following endpoints.• AMI: RR 0.73, 95% CI 0.61 to 0.87, NNTB 72, 10,958 participants, high quality of evidence.• Myocardial ischaemia: RR 0.43, 95% CI 0.27 to 0.70, NNTB seven, 1028 participants, moderate quality of evidence.• Supraventricular arrhythmias: RR 0.72, 95% CI 0.56 to 0.92, NNTB 111, 8794 participants, high quality of evidence.Beta-blockers significantly increased the occurrence of the following adverse events.• Hypotension: RR 1.50, 95% CI 1.38 to 1.64, NNTH 15, 10,947 participants, high quality of evidence.• Bradycardia: RR 2.24, 95% CI 1.49 to 3.35, NNTH 18, 11,083 participants, moderate quality of evidence.We found no clear evidence of an effect of beta-blockers on the following outcomes.• Ventricular arrhythmias: RR 0.64, 95% CI 0.30 to 1.33, 526 participants, moderate quality of evidence.• Congestive heart failure: RR 1.17, 95% CI 0.93 to 1.47, 9223 participants, moderate quality of evidence.• Length of hospital stay: mean difference -0.27 days, 95% CI -1.29 to 0.75, 601 participants, low quality of evidence.

AUTHORS' CONCLUSIONS

According to our findings, perioperative application of beta-blockers still plays a pivotal role in cardiac surgery , as they can substantially reduce the high burden of supraventricular and ventricular arrhythmias in the aftermath of surgery. Their influence on mortality, AMI, stroke, congestive heart failure, hypotension and bradycardia in this setting remains unclear.In non-cardiac surgery, evidence from low risk of bias trials shows an increase in all-cause mortality and stroke with the use of beta-blockers. As the quality of evidence is still low to moderate, more evidence is needed before a definitive conclusion can be drawn. The substantial reduction in supraventricular arrhythmias and AMI in this setting seems to be offset by the potential increase in mortality and stroke.

Perioperative beta blockade in noncardiac surgery: a systematic review for the 2014 ACC/AHA guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines

OBJECTIVE

To review the literature systematically to determine whether initiation of beta blockade within 45 days prior to noncardiac surgery reduces 30-day cardiovascular morbidity and mortality rates.

METHODS

PubMed (up to April 2013), Embase (up to April 2013), Cochrane Central Register of Controlled Trials (up to March 2013), and conference abstracts (January 2011 to April 2013) were searched for randomized controlled trials (RCTs) and cohort studies comparing perioperative beta blockade with inactive control during noncardiac surgery. Pooled relative risks (RRs) were calculated under the random-effects model. We conducted subgroup analyses to assess how the DECREASE-I (Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography), DECREASE-IV, and POISE-1 (Perioperative Ischemic Evaluation) trials influenced our conclusions.

RESULTS

We identified 17 studies, of which 16 were RCTs (12 043 participants) and 1 was a cohort study (348 participants). Aside from the DECREASE trials, all other RCTs initiated beta blockade within 1 day or less prior to surgery. Among RCTs, beta blockade decreased nonfatal myocardial infarction (MI) (RR: 0.69; 95% confidence interval [CI]: 0.58 to 0.82) but increased nonfatal stroke (RR: 1.76; 95% CI: 1.07 to 2.91), hypotension (RR: 1.47; 95% CI: 1.34 to 1.60), and bradycardia (RR: 2.61; 95% CI: 2.18 to 3.12). These findings were qualitatively unchanged after the DECREASE and POISE-1 trials were excluded. Effects on mortality rate differed significantly between the DECREASE trials and other trials. Beta blockers were associated with a trend toward reduced all-cause mortality rate in the DECREASE trials (RR: 0.42; 95% CI: 0.15 to 1.22) but with increased all-cause mortality rate in other trials (RR: 1.30; 95% CI: 1.03 to 1.64). Beta blockers reduced cardiovascular mortality rate in the DECREASE trials (RR: 0.17; 95% CI: 0.05 to 0.64) but were associated with trends toward increased cardiovascular mortality rate in other trials (RR: 1.25; 95% CI: 0.92 to 1.71). These differences were qualitatively unchanged after the POISE-1 trial was excluded.

CONCLUSIONS

Perioperative beta blockade started within 1 day or less before noncardiac surgery prevents nonfatal MI but increases risks of stroke, death, hypotension, and bradycardia. Without the controversial DECREASE studies, there are insufficient data on beta blockade started 2 or more days prior to surgery. Multicenter RCTs are needed to address this knowledge gap.

Perioperative beta blockade in noncardiac surgery: a systematic review for the 2014 ACC/AHA guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines

OBJECTIVE

To review the literature systematically to determine whether initiation of beta blockade within 45 days prior to noncardiac surgery reduces 30-day cardiovascular morbidity and mortality rates.

METHODS

PubMed (up to April 2013), Embase (up to April 2013), Cochrane Central Register of Controlled Trials (up to March 2013), and conference abstracts (January 2011 to April 2013) were searched for randomized controlled trials (RCTs) and cohort studies comparing perioperative beta blockade with inactive control during noncardiac surgery. Pooled relative risks (RRs) were calculated under the random-effects model. We conducted subgroup analyses to assess how the DECREASE-I (Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography), DECREASE-IV, and POISE-1 (Perioperative Ischemic Evaluation) trials influenced our conclusions.

RESULTS

We identified 17 studies, of which 16 were RCTs (12,043 participants) and 1 was a cohort study (348 participants). Aside from the DECREASE trials, all other RCTs initiated beta blockade within 1 day or less prior to surgery. Among RCTs, beta blockade decreased nonfatal myocardial infarction (MI) (RR: 0.69; 95% confidence interval [CI]: 0.58 to 0.82) but increased nonfatal stroke (RR: 1.76; 95% CI:1.07 to 2.91), hypotension (RR: 1.47; 95% CI: 1.34 to 1.60), and bradycardia (RR: 2.61; 95% CI: 2.18 to 3.12). These findings were qualitatively unchanged after the DECREASE and POISE-1 trials were excluded. Effects on mortality rate differed significantly between the DECREASE trials and other trials. Beta blockers were associated with a trend toward reduced all-cause mortality rate in the DECREASE trials (RR: 0.42; 95% CI: 0.15 to 1.22) but with increased all-cause mortality rate in other trials (RR: 1.30; 95% CI: 1.03 to 1.64). Beta blockers reduced cardiovascular mortality rate in the DECREASE trials (RR:0.17; 95% CI: 0.05 to 0.64) but were associated with trends toward increased cardiovascular mortality rate in other trials (RR: 1.25; 95% CI: 0.92 to 1.71). These differences were qualitatively unchanged after the POISE-1 trial was excluded.

CONCLUSIONS

Perioperative beta blockade started within 1 day or less before noncardiac surgery prevents nonfatal MI but increases risks of stroke, death, hypotension, and bradycardia. Without the controversial DECREASE studies, there are insufficient data on beta blockade started 2 or more days prior to surgery. Multicenter RCTs are needed to address this knowledge gap.

PURLs: Why you shouldn't start beta-blockers before surgery

A new meta-analysis finds that initiating beta-blockers before surgery increases patients' risk of death.

Management of postoperative complications: cardiovascular disease and volume management

Postoperative cardiovascular complications are common, predictable, and typically treatable in geriatric patients who have sustained fractures. Although intervention-specific data are sparse, observational evidence from high-performing geriatric fracture centers coupled with an understanding of geriatric principles can serve as a basis for treatment guidelines. Many patients can be safely and effectively managed with close attention to intravascular volume status, heart rate control, and minimization of other physiologic stresses, including pain and delirium. Many chronic cardiovascular therapies may be harmful in the immediate postoperative period, and can usually be safely omitted or attenuated until hemodynamic stability and mobility have been restored.