Lessons learned from a randomised controlled study of perioperative beta blockade in high risk patients undergoing emergency surgery

A Comparative Study of the Effect of Labetalol and Remifentanil on Pain Control After Bariatric Surgery

Background

Finding the optimal combination of anesthetics to maintain hemodynamic stability during surgery can be challenging. Traditionally, strong opioid analgesics such as fentanyl and its newer analogs have been used. However, the use of narcotics is associated with certain side effects.

Objectives

This study compares the effects of labetalol and remifentanil in pain control after bariatric surgery in Hazrat Rasool Akram Hospital.

Methods

This randomized, double-blind clinical trial was conducted on 48 laparoscopic bariatric surgery patients. The participants were randomly divided into two groups receiving remifentanil or labetalol. Postoperative pain was measured in the recovery unit using the numerical rating scale (NRS). This score was recorded upon entering recovery, and 30 minutes, 60 minutes, and 120 minutes after surgery for each patient. Also, the duration of anesthesia, the duration of the operation, the recovery time, the dose of the administered opioids, the volume of intravenous fluids, and the dose of administered propofol were recorded for each patient. Nausea and vomiting after the operation were also recorded as outcomes.

Results

There were no significant differences between the two groups regarding the mean duration of surgery and anesthesia, dose of the administered anesthetics, recovery period, nausea and vomiting, and the dose of analgesics after the operation. The mean pain intensity during the given period and also the trend of pain intensity changes between the two groups demonstrated no statistically significant differences (P = 0.112). During the operation, 9 subjects (37.5%) in the labetalol group and 16 (66.7%) in the remifentanil group needed more analgesics (rescue drug); in this regard, a significant difference was observed between the two groups (P = 0.043).

Conclusions

Based on the study's findings, there were no significant differences between labetalol and remifentanil in post and perioperative pain control. However, rescue drugs needed to maintain hemodynamic stability during laparoscopic surgery were significantly lower in patients who received labetalol than remifentanil. Postoperative complications were also comparable between labetalol and remifentanil.

Generalisability of randomised trials evaluating perioperative β-blocker therapy in noncardiac surgery

BACKGROUND

The limited applicability of evidence from RCTs in real-word practice is considered a potential bottleneck for evidence-based practice but rarely systematically assessed. Using our failure to recruit patients into a perioperative beta-blocker trial, we set out to analyse the restrictiveness and generalisability of trial eligibility criteria in a real-world cohort.

METHODS

We prospectively included adult patients (≥18 yr) scheduled for elective noncardiac surgery at an academic tertiary care facility who were screened for inclusion in a planned perioperative beta-blocker RCT, which was terminated owing to recruitment failure. The primary outcome was the proportion of screened patients who matched the eligibility criteria of 36 published RCTs included in a large Cochrane meta-analysis on perioperative beta-blocker therapy. The pragmatic/explanatory level of each RCT was assessed using the PRagmatic-Explanatory Continuum Indicator Summary 2 (PRECIS-2) score, which ranges from 9 points (indicating a very explanatory study) to 45 points (indicating a very pragmatic study).

RESULTS

A total of 2241 patients (54% female, n=1215; 52 [standard deviation, 20] yr) were included for the assessment of trial eligibility between October 2015 and January 2016. Only a small proportion of patients matched the inclusion and exclusion criteria for each of the 36 RCTs, ranging from 53% to 0%. The average proportion of patients who did match the eligibility criteria of all 36 RCTs was 6.5% (n=145; 95% confidence interval, 6.3-6.6). A higher PRECIS-2 score was associated with a higher proportion of matching patients (P<0.001).

CONCLUSIONS

Trial eligibility criteria in perioperative beta-blocker therapy trials are overly restrictive and not generalisable to a real-world surgical population.

CLINICAL TRIAL REGISTRATION

EudraCT#: 2015-002366-23.

Challenges in optimising recovery after emergency laparotomy

Standardised peri-operative care pathways for patients undergoing emergency laparotomy or laparoscopy for non-traumatic pathologies have been shown to be inadequate and associated with high morbidity and mortality. Recent research has highlighted this problem and showed that simple pathways with 'rescue' interventions have been associated with reduced mortality when implemented successfully. These rescue pathways have focused on early diagnosis and surgery, specialist surgeon and anaesthetist involvement, goal-directed therapy and intensive or intermediary postoperative care for high-risk patients. In elective surgery, enhanced recovery has resulted in reduced length of stay and morbidity by the application of procedure-specific, evidence-based interventions inside rigorously implemented patient pathways based on multidisciplinary co-operation. The focus has been on attenuation of peri-operative stress and pain management to facilitate early recovery. Patients undergoing emergency laparotomy are a heterogeneous group consisting mostly of patients with intestinal perforations and/or obstruction with varying levels of comorbidity and frailty. However, present knowledge of the different pathophysiology and peri-operative trajectory of complications in these patient groups is limited. In order to move beyond rescue pathways and to establish enhanced recovery for emergency laparotomy, it is essential that research on both the peri-operative pathophysiology of the different main patient groups - intestinal obstruction and perforation - and the potentially differentiated impact of interventions is carried out. Procedure- and pathology-specific knowledge is lacking on key elements of peri-operative care, such as: multimodal analgesia; haemodynamic optimisation and fluid management; attenuation of surgical stress; nutritional optimisation; facilitation of mobilisation; and the optimal use and organisation of specialised wards and improved interdisciplinary collaboration. As such, the future challenges in improving peri-operative patient care in emergency laparotomy are moving from simple rescue pathways to establish research that can form a basis for morbidity- and procedure-specific enhanced recovery protocols as seen in elective surgery.

Perioperative beta-blockers for preventing surgery-related mortality and morbidity in adults undergoing non-cardiac surgery

BACKGROUND

Randomized controlled trials (RCTs) have yielded conflicting results regarding the ability of beta-blockers to influence perioperative cardiovascular morbidity and mortality. Thus routine prescription of these drugs in an unselected population remains a controversial issue. A previous version of this review assessing the effectiveness of perioperative beta-blockers in cardiac and non-cardiac surgery was last published in 2018. The previous review has now been split into two reviews according to type of surgery. This is an update, and assesses the evidence in non-cardiac surgery only.

OBJECTIVES

To assess the effectiveness of perioperatively administered beta-blockers for the prevention of surgery-related mortality and morbidity in adults undergoing non-cardiac surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, Biosis Previews and Conference Proceedings Citation Index-Science on 28 June 2019. We searched clinical trials registers and grey literature, and conducted backward- and forward-citation searching of relevant articles.

SELECTION CRITERIA

We included RCTs and quasi-randomized studies comparing beta-blockers with a control (placebo or standard care) administered during the perioperative period to adults undergoing non-cardiac surgery. If studies included surgery with different types of anaesthesia, we included them if 70% participants, or at least 100 participants, received general anaesthesia. We excluded studies in which all participants in the standard care control group were given a pharmacological agent that was not given to participants in the intervention group, studies in which all participants in the control group were given a beta-blocker, and studies in which beta-blockers were given with an additional agent (e.g. magnesium). We excluded studies that did not measure or report review outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, and assessed risks of bias. We assessed the certainty of evidence with GRADE.

MAIN RESULTS

We included 83 RCTs with 14,967 participants; we found no quasi-randomized studies. All participants were undergoing non-cardiac surgery, and types of surgery ranged from low to high risk. Types of beta-blockers were: propranolol, metoprolol, esmolol, landiolol, nadolol, atenolol, labetalol, oxprenolol, and pindolol. In nine studies, beta-blockers were titrated according to heart rate or blood pressure. Duration of administration varied between studies, as did the time at which drugs were administered; in most studies, it was intraoperatively, but in 18 studies it was before surgery, in six postoperatively, one multi-arm study included groups of different timings, and one study did not report timing of drug administration. Overall, we found that more than half of the studies did not sufficiently report methods used for randomization. All studies in which the control was standard care were at high risk of performance bias because of the open-label study design. Only two studies were prospectively registered with clinical trials registers, which limited the assessment of reporting bias. In six studies, participants in the control group were given beta-blockers as rescue therapy during the study period.The evidence for all-cause mortality at 30 days was uncertain; based on the risk of death in the control group of 25 per 1000, the effect with beta-blockers was between two fewer and 13 more per 1000 (risk ratio (RR) 1.17, 95% confidence interval (CI) 0.89 to 1.54; 16 studies, 11,446 participants; low-certainty evidence). Beta-blockers may reduce the incidence of myocardial infarction by 13 fewer incidences per 1000 (RR 0.72, 95% CI 0.60 to 0.87; 12 studies, 10,520 participants; low-certainty evidence). We found no evidence of a difference in cerebrovascular events (RR 1.65, 95% CI 0.97 to 2.81; 6 studies, 9460 participants; low-certainty evidence), or in ventricular arrhythmias (RR 0.72, 95% CI 0.35 to 1.47; 5 studies, 476 participants; very low-certainty evidence). Beta-blockers may reduce atrial fibrillation or flutter by 26 fewer incidences per 1000 (RR 0.41, 95% CI 0.21 to 0.79; 9 studies, 9080 participants; low-certainty evidence). However, beta-blockers may increase bradycardia by 55 more incidences per 1000 (RR 2.49, 95% CI 1.74 to 3.56; 49 studies, 12,239 participants; low-certainty evidence), and hypotension by 44 more per 1000 (RR 1.40, 95% CI 1.29 to 1.51; 49 studies, 12,304 participants; moderate-certainty evidence).We downgraded the certainty of the evidence owing to study limitations; some studies had high risks of bias, and the effects were sometimes altered when we excluded studies with a standard care control group (including only placebo-controlled trials showed an increase in early mortality and cerebrovascular events with beta-blockers). We also downgraded for inconsistency; one large, well-conducted, international study found a reduction in myocardial infarction, and an increase in cerebrovascular events and all-cause mortality, when beta-blockers were used, but other studies showed no evidence of a difference. We could not explain the reason for the inconsistency in the evidence for ventricular arrhythmias, and we also downgraded this outcome for imprecision because we found few studies with few participants.

AUTHORS' CONCLUSIONS

The evidence for early all-cause mortality with perioperative beta-blockers was uncertain. We found no evidence of a difference in cerebrovascular events or ventricular arrhythmias, and the certainty of the evidence for these outcomes was low and very low. We found low-certainty evidence that beta-blockers may reduce atrial fibrillation and myocardial infarctions. However, beta-blockers may increase bradycardia (low-certainty evidence) and probably increase hypotension (moderate-certainty evidence). Further evidence from large placebo-controlled trials is likely to increase the certainty of these findings, and we recommend the assessment of impact on quality of life. We found 18 studies awaiting classification; inclusion of these studies in future updates may also increase the certainty of the evidence.

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 88 randomized controlled trials with 19,161 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 evidence.• Acute myocardial infarction (AMI): RR 1.04, 95% CI 0.71 to 1.51, 3553 participants, moderate quality evidence.• Myocardial ischaemia: RR 0.51, 95% CI 0.25 to 1.05, 166 participants, low quality evidence.• Cerebrovascular events: RR 1.52, 95% CI 0.58 to 4.02, 1400 participants, low quality evidence.• Hypotension: RR 1.54, 95% CI 0.67 to 3.51, 558 participants, low quality evidence.• Bradycardia: RR 1.61, 95% CI 0.97 to 2.66, 660 participants, low quality evidence.• Congestive heart failure: RR 0.22, 95% CI 0.04 to 1.34, 311 participants, low quality 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 evidence.• Supraventricular arrhythmias: RR 0.44, 95% CI 0.36 to 0.53, NNTB five, 6420 participants, high quality 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 evidence).NON-CARDIAC SURGERY (35 trials)Beta-blockers significantly increased the occurrence of the following adverse events.• All-cause mortality: RR 1.25, 95% CI 1.00 to 1.57, 11,413 participants, low quality of evidence, number needed to treat for an additional harmful outcome (NNTH) 167.• Hypotension: RR 1.50, 95% CI 1.38 to 1.64, NNTH 16, 10,947 participants, high quality evidence.• Bradycardia: RR 2.23, 95% CI 1.48 to 3.36, NNTH 21, 11,033 participants, moderate quality evidence.We found a potential increase in the occurrence of the following outcomes with the use of beta-blockers.• Cerebrovascular events: RR 1.59, 95% CI 0.93 to 2.71, 9150 participants, low quality 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 265, 8648 participants.Beta-blockers significantly reduced the occurrence of the following endpoints.• AMI: RR 0.73, 95% CI 0.61 to 0.87, NNTB 76, 10,958 participants, high quality evidence.• Myocardial ischaemia: RR 0.51, 95% CI 0.34 to 0.77, NNTB nine, 978 participants, moderate quality evidence.• Supraventricular arrhythmias: RR 0.73, 95% CI 0.57 to 0.94, NNTB 112, 8744 participants, high quality evidence.We found no clear evidence of an effect of beta-blockers on the following outcomes.• Ventricular arrhythmias: RR 0.68, 95% CI 0.31 to 1.49, 476 participants, moderate quality evidence.• Congestive heart failure: RR 1.18, 95% CI 0.94 to 1.48, 9173 participants, moderate quality evidence.• Length of hospital stay: mean difference -0.45 days, 95% CI -1.75 to 0.84, 551 participants, low quality 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 shows an association of beta-blockers with increased all-cause mortality. Data from low risk of bias trials further suggests an increase in stroke rate 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 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.

Patterns of β-blocker initiation in patients undergoing intermediate to high-risk noncardiac surgery

BACKGROUND

Based on 2 small randomized controlled trials (RCTs) from the 1990s, β-blockers were promoted to prevent perioperative cardiac events in patients undergoing noncardiac surgery. In 2008, a large RCT (POISE trial) showed an increased mortality risk associated with perioperative β-blockade, raising concerns about an extensive β-Blocker use.

OBJECTIVES

The objective of the study is to examine patterns of β-Blocker initiation among patients undergoing noncardiac elective surgery in the US.

METHODS

From a large, nationwide US health care insurer, we identified patients ≥18 years old who underwent moderate- to high-risk noncardiac elective surgery between 2003 and 2012 and initiated a β-Blocker within 30 days before surgery. We evaluated temporal trends and assessed the impact of the POISE trial on perioperative β-Blocker initiation. We also evaluated patient characteristics and examined the effect of temporal proximity to surgery on the likelihood of β-Blocker initiation.

RESULTS

Of 499,752 patients undergoing surgery, 9,014 (18 per 1,000 patients) initiated a β-Blocker. β-Blocker initiation increased from 12 per 1,000 patients in 2003 to 23 before POISE, after which it decreased to 14 by December 2012 (P = .0001). β-Blocker initiation remained relatively high among patients undergoing vascular surgery or with Revised Cardiac Risk Index score ≥ 2. Proximity to surgery was highly predictive of β-Blocker initiation (odds ratio 3.34, 95% CI 3.17-3.51).

CONCLUSIONS

After a period of a rapidly increasing trend, perioperative β-Blocker initiation decreased sharply in the second half of 2008 and continued to decrease afterwards. β-Blocker initiation remained relatively high in patients with Revised Cardiac Risk Index score ≥2 and in those undergoing major vascular surgery.

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.

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

Background

Current European and American guidelines recommend the perioperative initiation of a course of β-blockers in those at risk of cardiac events undergoing high- or intermediate-risk surgery or vascular surgery. The Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography (DECREASE) family of trials, the bedrock of evidence for this, are no longer secure. We therefore conducted a meta-analysis of randomised controlled trials of β-blockade on perioperative mortality, non-fatal myocardial infarction, stroke and hypotension in non-cardiac surgery using the secure data.

Methods

The randomised controlled trials of initiation of β-blockers before non-cardiac surgery were examined. Primary outcome was all-cause mortality at 30 days or at discharge. The DECREASE trials were separately analysed.

Results

Nine secure trials totalling 10 529 patients, 291 of whom died, met the criteria. Initiation of a course of β-blockers before surgery caused a 27% risk increase in 30-day all-cause mortality (p=0.04). The DECREASE family of studies substantially contradict the meta-analysis of the secure trials on the effect of mortality (p=0.05 for divergence). In the secure trials, β-blockade reduced non-fatal myocardial infarction (RR 0.73, p=0.001) but increased stroke (RR 1.73, p=0.05) and hypotension (RR 1.51, p<0.00001). These results were dominated by one large trial.

Conclusions

Guideline bodies should retract their recommendations based on fictitious data without further delay. This should not be blocked by dispute over allocation of blame. The well-conducted trials indicate a statistically significant 27% increase in mortality from the initiation of perioperative β-blockade that guidelines currently recommend. Any remaining enthusiasts might best channel their energy into a further randomised trial which should be designed carefully and conducted honestly.

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.

ß-Blockers reduce mortality in patients undergoing high-risk non-cardiac surgery

BACKGROUND

ß-Adrenergic receptor antagonists (beta-blockers) are frequently used with the aim of reducing perioperative myocardial ischemia and infarction. However, randomized clinical trials specifically designed to evaluate the effects of beta-blockers on mortality in patients undergoing non-cardiac surgery have yielded conflicting results.

OBJECTIVE

This study aimed to examine the effect of perioperative ß-blockers on total and cardiovascular mortality in patients undergoing non-cardiac surgery.

METHODS

We conducted a meta-analysis of randomized clinical trials that examined the effects of ß-blockers versus placebo on cardiovascular and all-cause mortality in patients undergoing non-cardiac surgery. We extracted data from articles published before 30 November 2009 in peer-reviewed journals indexed in MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE and CINAHL. Data extraction was carried out independently by two reviewers on the basis of an intent-to-treat approach, and inconsistencies were discussed and resolved in conference. The present meta-analysis was undertaken according to the Quality of Reporting of Meta-analyses (QUORUM) statement.

RESULTS

A total of 2148 records were screened, from which we identified 74 randomized controlled trials for non-cardiac surgery. After excluding 49 studies that did not report the clinical outcome of interest or were subanalyses or presented duplicate data, the final search left 25 clinical trials. Treatment with ß-blockers had no significant effect on all-cause mortality (odds ratio [OR] 1.15; 95% confidence interval [CI] 0.92, 1.43; p = 0.2717) or cardiovascular mortality (OR 1.13; 95% CI 0.85, 1.51; p = 0.5855). However, surgical risk category markedly differed across the studies. According to Joint American College of Cardiology and American Heart Association guidelines for perioperative assessment of patients having non-cardiac surgery, five trials evaluated the effect of ß-blockers in patients treated with emergency and vascular surgery (high-risk category) whereas 15 and five trials evaluated the effect of ß-blockers in intermediate low and intermediate high surgical risk categories, respectively. Subgroup analyses showed that the surgical risk category and dose titration of ß-blockers to target heart rate affected the estimate of the effect of ß-blockers for all-cause and cardiovascular mortality. ß-Blockers reduced total mortality by 61% more in patients who underwent high-risk surgery than in those who underwent intermediate high- or intermediate low-risk surgery. When cardiovascular mortality was assessed, the benefit of ß-blockers was 74% greater in trials that titrated ßblockers to heart rate than in trials that did not, although formal statistical significance was not achieved.

CONCLUSIONS

These data suggest that ß-blockers may be useful for reducing mortality in patients who undergo high-risk non-cardiac surgery.

State of the science: beta-blockers and reduction of perioperative cardiac events

This article evaluates the current literature concerning the use of perioperative beta-blockade to reduce cardiac events in hopes that it may provide direction to clinicians or demonstrate gaps in medical knowledge, thus revealing areas suitable for future study. The current standard of practice for the use of perioperative beta-blockade in preoperative patients is outlined in the American College of Cardiology (ACC) and American Heart Association (AHA) guidelines. Findings differ as to the risk and benefit of using beta-blockers perioperatively to reduce cardiac events. Further research is needed to support the ACC/AHA recommendations. It is essential that the decision to use beta-blockade be made on a case-by-case basis with adequate risk stratification as part of the criteria.

β-blockers and risk of all-cause mortality in non-cardiac surgery

Myocardial ischemia is a frequent complication in patients undergoing non-cardiac surgery and β-blockers may exert a protective effect. The main benefit of β-blockers in perioperative cardiovascular morbidity and mortality is believed to be linked to specific effects on myocardial oxygen supply and demand. β-blockers may exert anti-inflammatory and anti-arrhythmic effects. Randomized clinical trials which evaluated the effects of β-blockers on all-cause mortality in patients undergoing non-cardiac surgery have yielded conflicting results. In 9 trials, 10,544 patients with non-cardiac surgery were randomized to β-blockers (n = 5274) or placebo (n = 5270) and there were a total of 304 deaths. Patients randomized to β-blockers group showed a 19% increased risk of all-cause mortality (odds ratio [OR] 1.19, 95% confidence interval (CI) 0.95-1.50; p = 0.135). However, trials included in the meta-analysis differed in several aspects, and a significant degree of heterogeneity (I 2 = 46.5%) was noted. A recent analysis showed that the surgical risk category had a substantial influence on the overall estimate of the effect of β-blockers. Compared with patients in the intermediate-high-surgical-risk category, those in the high-risk category showed a 73% reduction in the risk of total mortality with β-blockers compared with placebo (OR 0.27, 95% CI 0.10-0.71, p = 0.016). These data suggest that perioperative β-blockers confer a benefit which is mostly limited to patients undergoing high-risk surgery.

Perioperative beta blockers in patients having non-cardiac surgery: a meta-analysis

BACKGROUND

American College of Cardiology and American Heart Association (ACC/AHA) guidelines on perioperative assessment recommend perioperative beta blockers for non-cardiac surgery, although results of some clinical trials seem not to support this recommendation. We aimed to critically review the evidence to assess the use of perioperative beta blockers in patients having non-cardiac surgery.

METHODS

We searched Pubmed and Embase for randomised controlled trials investigating the use of beta blockers in non-cardiac surgery. We extracted data for 30-day all-cause mortality, cardiovascular mortality, non-fatal myocardial infarction, non-fatal stroke, heart failure, and myocardial ischaemia, safety outcomes of perioperative bradycardia, hypotension, and bronchospasm.

FINDINGS

33 trials included 12 306 patients. beta blockers were not associated with any significant reduction in the risk of all-cause mortality, cardiovascular mortality, or heart failure, but were associated with a decrease (odds ratio [OR] 0.65, 95% CI 0.54-0.79) in non-fatal myocardial infarction (number needed to treat [NNT] 63) and decrease (OR 0.36, 0.26-0.50) in myocardial ischaemia (NNT 16) at the expense of an increase (OR 2.01, 1.27-3.68) in non-fatal strokes (number needed to harm [NNH] 293). The beneficial effects were driven mainly by trials with high risk of bias. For the safety outcomes, beta blockers were associated with a high risk of perioperative bradycardia requiring treatment (NNH 22), and perioperative hypotension requiring treatment (NNH 17). We recorded no increased risk of bronchospasm.

INTERPRETATION

Evidence does not support the use of beta-blocker therapy for the prevention of perioperative clinical outcomes in patients having non-cardiac surgery. The ACC/AHA guidelines committee should soften their advocacy for this intervention until conclusive evidence is available.