2009 ACCF/AHA Focused Update on Perioperative Beta Blockade Incorporated Into the ACC/AHA 2007 Guidelines on Perioperative Cardiovascular Evaluation and Care for Noncardiac Surgery

The effect of postoperative myocardial ischemia on long-term survival after vascular surgery

INTRODUCTION

The impact of a postoperative troponin elevation on long-term survival after vascular surgery is not well-defined. We hypothesize that a postoperative troponin elevation is associated with significantly reduced long-term survival.

METHODS

The Vascular Study Group of New England registry identified all patients who underwent carotid revascularization, open abdominal aortic aneurysm repair (AAA), endovascular AAA repair, or infrainguinal lower extremity bypass (2003-2011). The association of postoperative troponin elevation and myocardial infarction (MI) with 5-year survival was evaluated. Multivariable models identified predictors of survival and of postoperative myocardial ischemia.

RESULTS

In the entire cohort (n = 16,363), the incidence of postoperative troponin elevation was 1.3% (n = 211) and for MI was 1.6% (n = 264). Incidences differed across procedures (P < .0001) with the highest incidences after open AAA: troponin elevation, 3.9% (n = 74); MI, 5.1% (n = 96). On Kaplan-Meier analysis, any postoperative myocardial ischemia predicted reduced survival over 5 years postoperatively: no ischemia, 73% (standard error [SE], 0.5%); troponin elevation, 54% (SE, 4%); MI, 33% (SE, 4%) (P < .0001). This pattern was observed for each procedure subgroup analysis (P < .0001). Troponin elevation (hazard ratio, 1.45; 95% confidence interval, 1.1-2.0; P = .02) and MI (hazard ratio, 2.9; 95% confidence interval, 2.3-3.8; P < .0001) were independent predictors of reduced survival at 5 years.

CONCLUSIONS

Postoperative troponin elevation and MI predict a 26% or a 55% relatively lower survival in the 5 years following a vascular surgical procedure, respectively, compared with patients who do not experience myocardial ischemia. This highlights the need to better characterize factors leading to postoperative myocardial ischemia. Postoperative troponin elevation, either alone, or in combination with an MI, may be a useful marker for identifying high-risk patients who might benefit from more aggressive optimization in hopes of reducing adverse long-term outcomes.

Understanding and managing medication in elderly people

Ageing alters drug handling by the body (pharmacokinetics) and response to medications (pharmacodynamics). Multiple comorbidities increase the risk of adverse drug reactions and medication burden, with increased potential for drug interactions. Elderly people are seldom included in clinical trials, so underestimation of benefits and overestimation of risk may lead to under-treatment. Cognitive and functional changes associated with ageing may make it difficult for elderly people to adhere to treatment regimens. In this review, we consider these issues, with particular reference to drugs prescribed for gynaecology patients (the 'gynaecology formulary'). It will focus on key areas of gynaecological practice, including prescribing anticholinergic drugs, hormone treatments and anticancer drugs, and perioperative issues relating to anaesthesia, analgesia and anticoagulation. Implications of common comorbidities, including osteoporosis, diabetes mellitus and cardiovascular disease, for prescribing in gynaecological patients will also be considered.

Ascertainment of any and all neurologic and myocardial damage in carotid revascularization: the key to optimization?

The majority of carotid revascularization procedures performed at present are in asymptomatic patients. Since such procedures convey no immediate benefit, but rather protect from future hazard, optimization of procedural safety is mandatory. The authors focus their discussion on the methodologies that assess periprocedural myocardial damage and brain injury, as used in past clinical trials, from the fields of perioperative medicine and neurovascular imaging, and discuss methodologies to reduce both events in carotid revascularization.

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.

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.

Risk of elective major noncardiac surgery after coronary stent insertion: a population-based study

BACKGROUND

Guidelines recommend that noncardiac surgery be delayed until 30 to 45 days after bare-metal stent implantation and 1 year after drug-eluting stent implantation.

METHODS AND RESULTS

We used linked registry data and population-based administrative health care databases to conduct a cohort study of 8116 patients (≥40 years of age) who underwent major elective noncardiac surgery in Ontario, Canada between 2003 and 2009, and received coronary stents within 10 years before surgery. Approximately 34% (n=2725) underwent stent insertion within 2 years before surgery, of whom 905 (33%) received drug-eluting stents. For comparison, we assembled a separate cohort of 341 350 surgical patients who had not undergone coronary revascularization. The primary outcome was 30-day major adverse cardiac events (mortality, readmission for acute coronary syndrome, or repeat coronary revascularization). The overall rate of 30-day events in patients with coronary stents was 2.1% (n=170). When the interval between stent insertion and surgery was <45 days, event rates were high for bare-metal (6.7%) and drug-eluting (20.0%) stents. When the interval was 45 to 180 days, the event rate for bare-metal stents was 2.6%, approaching that of intermediate-risk nonrevascularized individuals. Adjusted analyses suggested that event rates were increased if this interval exceeded 180 days. For drug-eluting stents, the event rate was 1.2% once the interval exceeded 180 days, approaching that of intermediate-risk nonrevascularized individuals.

CONCLUSIONS

The earliest optimal time for elective surgery is 46 to 180 days after bare-metal stent implantation or >180 days after drug-eluting stent implantation.

Integrating perioperative information from divergent sources

The enormous diversity of physician practices, including specialists, and patient requirements and comorbidities make integration of appropriate perioperative information difficult. Lack of communicating computer systems adds to the difficulty of assembling data. Meta analysis and evidence-based studies indicate that far too many tests are performed perioperatively. Guidelines for appropriate perioperative management have been formulated by several specialties. Education as to current findings and requirements should be better communicated to surgeons, consultants, and patients to improve healthcare needs and at the same time decrease costs. Means to better communication by interpersonal collaboration are outlined.

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.

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.

The avantgarde carbostent in patients scheduled for undelayable noncardiac surgery

Background. Treatment of patients who need coronary revascularization before undelayable non-cardiac surgery is challenging. Methods. We assessed the safety and efficacy of percutaneous coronary interventions (PCI) using the Avantgarde( TM) Carbostent (CID, Italy) in patients undergoing PCI before undelayable non-cardiac surgery. The Multiplate analyzer point-of-care was used to assess residual platelet reactivity. One major cardiac events (MACE, defined as death, myocardial infarction, and stent thrombosis and major bleeding) were assessed. Results. 42 consecutive patients were analyzed. Total stent length ≥25 mm was observed in 16 (37%) patients. Multivessel stenting was performed in 11 (31.5%) patients. Clopidogrel was interrupted 5 days before surgery in 35 patients, whereas it was stopped the day of the surgery in 7 patients. Surgery was performed after 27 ± 9 (7-42) days from PCI. MACE occurred in one patient (2.4%; 95% confidence interval: 0.01-13%), who had fatal acute myocardial infarction 3 days after abdominal aortic aneurysm surgery and 12 days after stent implantation. No case of major bleeding in the postoperative phase was observed. Conclusions. The present pilot study suggests that, although at least 10-14 days of dual antiplatelet therapy remain mandatory, the Avantgarde( TM) stent seems to have a role in patients requiring undelayable surgery.

β-blocker withdrawal among patients presenting for surgery from home

OBJECTIVE

This study sought to measure the prevalence of perioperative β-blocker noncompliance by patients who were prescribed long-term β-blocker therapy and presented for surgery from home. The effect of patient noncompliance on the presenting heart rate on the day of surgery also was examined.

DESIGN

Prospective observational study with outcome data obtained from reviews of medical records.

SETTING

The preoperative clinic and operating rooms of a Veterans Administration hospital.

PARTICIPANTS

Patients on long-term β-blocker therapy who presented from home for surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Demographic and comorbidity data and data on self-reported compliance to β-blocker therapy, vital signs on the initial day of surgery, and recent ambulatory vital signs were collected. Ten of 50 subjects (20%; 95% confidence interval, 9-31) reported not taking their β-blocker on the day of surgery. These self-reported nonadherers exhibited a higher presenting heart rate on the day of surgery than adherent subjects (median, 78 v 65 beats/min; p = 0.02 by Wilcoxon rank-sum test). The difference-in-difference analysis in heart rate between baseline primary care and the day of surgery also was statistically significant between compliant and noncompliant subjects (-7 v + 12.5 beats/min; p < 0.00001).

CONCLUSIONS

Patient self-report and physiologic data documented a failure to take β-blockers and possible β-blocker withdrawal in 20% of patients who presented for surgery from home. If these findings are confirmed in larger studies, improved patient understanding of and compliance with medication instructions during preoperative visits should be a focus of future quality improvement initiatives.

Diastolic dysfunction and heart failure with a preserved ejection fraction: Relevance in critical illness and anaesthesia

Epidemiological and clinical studies suggest that HF with a preserved ejection fraction will become the more common form of HF which clinicians will encounter. The spectrum of diastolic disease extends from the asymptomatic phase to fulminant cardiac failure. These patients are commonly encountered in operating rooms and critical care units. A clearer understanding of the underlying pathophysiology and clinical implications of HF with a preserved ejection fraction is fundamental to directing further research and to evaluate interventions. This review highlights the impact of diastolic dysfunction and HF with a preserved ejection fraction during the perioperative period and during critical illness.

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.

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.

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.

The relationship between preoperative and primary care blood pressure among veterans presenting from home for surgery: is there evidence for anesthesiologist-initiated blood pressure referral?

BACKGROUND

American College of Cardiology/American Heart Association guidelines describe the perioperative evaluation as "a unique opportunity to identify patients with hypertension"; however, factors such as anticipatory stress or medication noncompliance may induce a bias toward higher blood pressure, leaving clinicians unsure about how to interpret preoperative hypertension. Information describing the relationship between preoperative intake blood pressure and primary care measurements could help anesthesiologists make primary care referrals for improved blood pressure control in an evidence-based fashion. We hypothesized that the preoperative examination provides a useful basis for initiating primary care blood pressure referral.

METHODS

We analyzed retrospective data on 2807 patients who arrived from home for surgery and who were subsequently evaluated within 6 months after surgery in the primary care center of the same institution. After descriptive analysis, we conducted multiple linear regression analysis to identify day-of-surgery (DOS) factors associated with subsequent primary care blood pressure. We calculated the sensitivity, specificity, and positive and negative predictive value of different blood pressure referral thresholds using both a single-measurement and a 2-stage screen incorporating recent preoperative and DOS measurements for identifying patients with subsequently elevated primary care blood pressure.

RESULTS

DOS systolic blood pressure (SBP) was higher than subsequent primary care SBP by a mean bias of 5.5 mm Hg (95% limits of agreement + 43.8 to -32.8). DOS diastolic blood pressure (DBP) was higher than subsequent primary care DBP by a mean bias of 1.5 mm Hg (95% limits of agreement +13.0 to -10.0). Linear regression of DOS factors explained 19% of the variability in primary care SBP and 29% of the variability in DBP. Accounting for the observed bias, a 2-stage SBP referral screen requiring preoperative clinic SBP ≥140 mm Hg and DOS SBP ≥146 mm Hg had 95.9% estimated specificity (95% confidence interval [CI] 94.4 to 97.0) for identifying subsequent primary care SBP ≥140 mm Hg and estimated sensitivity of 26.8% (95% CI 22.0 to 32.0). A similarly high specificity using a single DOS SBP required a threshold SBP ≥160 mm Hg, for which estimated specificity was 95.2% (95% CI 94.2 to 96.1). For DBP, a presenting DOS DBP ≥92 mm Hg had 95.7% specificity (95% CI 94.8 to 96.4) for subsequent primary care DBP ≥90 mm Hg with a sensitivity of 18.8% (95% CI 14.4 to 24.0).

CONCLUSION

A small bias toward higher DOS blood pressures relative to subsequent primary care measurements was observed. DOS factors predicted only a small proportion of the observed variation. Accounting for the observed bias, a 2-stage SBP threshold and a single-reading DBP threshold were highly specific though insensitive for identifying subsequent primary care blood pressure elevation.

[Preoperative risk evaluation from the perspective of anaesthesiology]

Medical and technical progress together with demographic changes has led to a more complex perioperative care for patients. Accordingly, an optimal preoperative assessment in particular an adequate risk evaluation is more important than ever. A recently published joint recommendation of the German Society of Anaesthesiology and Intensive Care Medicine, the German Society of Surgery and the German Society of Internal Medicine aims to reduce considerable uncertainties in the preoperative risk evaluation especially with regard to"technical tests" by providing transparent and comprehensive arrangements. Consequently, routine screening will be abandoned in favour of targeted patient and operation-oriented individual risk assessment. This approach will change the preoperative risk evaluation in a scientific, organisational and economic way. The following article on preoperative risk evaluation is based on the valuable and helpful recommendation and aims to provide additional important aspects from the perspective of anaesthesiologists.

Association of echocardiography before major elective non-cardiac surgery with postoperative survival and length of hospital stay: population based cohort study

OBJECTIVE

To determine the association of resting echocardiography before elective intermediate to high risk non-cardiac surgery with survival and length of hospital stay.

DESIGN

Population based retrospective cohort study.

SETTING

Acute care hospitals in Ontario, Canada, between 1 April 1999 and 31 March 2008.

PARTICIPANTS

Patients aged over 40 years who had elective intermediate to high risk non-cardiac surgery.

INTERVENTION

Resting echocardiography within 6 months before surgery.

MAIN OUTCOME MEASURES

Postoperative survival (30 days and 1 year) and length of hospital stay; postoperative surgical site infection as an outcome for which no association with echocardiography would be expected.

RESULTS

Of the 264,823 patients in the entire cohort, 15.1% (n = 40,084) had echocardiography. After use of propensity score methods to assemble a matched cohort (n = 70,996) that reduced differences between patients who had or had not had echocardiography, echocardiography was associated with increases in 30 day mortality (relative risk 1.14, 95% confidence interval 1.02 to 1.27), 1 year mortality (1.07, 1.01 to 1.12), and length of hospital stay but no difference in surgical site infections (1.03, 0.98 to 1.06). The association with mortality was influenced (P = 0.02) by whether patients had had stress testing or had risk factors for cardiac complications. No association existed between echocardiography and mortality among patients who had stress testing (relative risk 1.01, 0.92 to 1.11) or among patients at high risk who had not had stress testing (1.00, 0.87 to 1.13). However, echocardiography was associated with mortality in patients at low risk (relative risk 1.44, 1.14 to 1.82) and intermediate risk (1.10, 1.02 to 1.18) who had not had stress testing.

CONCLUSIONS

Preoperative echocardiography was not associated with improved survival or shorter hospital stay after major non-cardiac surgery. These findings highlight the need for further research to guide better use of this common preoperative test.

Good news for β-blockers in perioperative medicine

Myocardial ischemia is a relatively frequent complication in patients undergoing non-cardiac surgery and β-blockers may have a protective effect. β-blockers reduce the oxygen supply:demand ratio, and exert anti-inflammatory and anti-arrhythmic effects. However, randomized trials, specifically conducted to test this hypothesis, yielded conflicting results. The absolute risk for cardiac mortality and morbidity during and after non-cardiac surgery varies between patient groups defined by surgical risk categories, making it difficult to establish a risk:benefit ratio. We discuss the hypothesis that the protective effect of β-blockers on cardiovascular outcome differs across the different risk classes of surgical procedures, thereby explaining the conflicting evidence across studies. In particular, we examine the results of a recent meta-analysis that suggests that β-blockers may reduce mortality in patients under going high-risk non-cardiac surgery.