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

A Randomised Controlled Trial of Pharmacist Medication Histories and Supplementary Prescribing on Medication Errors in Postoperative Medications

Errors in the management of regular medications at the time of hospital admission are common. This randomised controlled three-arm parallel-group trial examined the impact of pharmacist medication history taking and pharmacist supplementary prescribing on unintentional omissions of postoperative medications in a large perioperative service. Participants included elective surgical patients taking regular medications with a postoperative hospital stay of one night or more. Patients were randomly assigned, on admission, to usual care (n=120), a pharmacist medication history only (n=120) or pharmacist medication history and supplementary prescribing (n=120). A medication history involved the pharmacist interviewing the patient preoperatively and documenting a medication history in the medical record. In the supplementary prescribing group the patients’ regular medicines were also prescribed on the inpatient medication chart by the pharmacist, so that dosing could proceed as soon as possible after surgery without the need to wait for medical review. The estimate marginal mean number of missed doses during a patients hospital stay was 1.07 in the pharmacist supplementary prescribing group, which was significantly less than both the pharmacist history group (3.30) and the control group (3.21) (P <0.001). The number of medications charted at an incorrect dose or frequency was significantly reduced in the pharmacist history group and further reduced in the prescribing group (P <0.001). We conclude that many patients miss doses of regular medication during their hospital stay and preoperative medication history taking and supplementary prescribing by a pharmacist can reduce this.

Socioeconomic position is not associated with 30-day or 1-year mortality in demographically diverse vascular surgery patients

OBJECTIVES

Disparities in outcomes after surgical procedures have been attributed to race, sex, use of private insurance, and socioeconomic position (SEP). The purpose of this study was to determine the impact of SEP on mortality after lower-extremity bypass (LEB) surgery in a diverse patient population with extremes of SEP.

DESIGN

Analysis of an electronic medical database.

SETTING

A tertiary care hospital in a demographically diverse section of a large metropolitan area.

PARTICIPANTS

Six hundred nine (158 white men, 156 nonwhite men, 100 white women, and 195 non-white women) patients undergoing infrarenal lower-extremity arterial bypass surgery from July 1, 2002, to December 31, 2007.

MEASUREMENTS AND RESULTS

SEP was estimated using data from the 2000 US Census. The effects of race, sex, various comorbidities, the Revised Cardiac Risk Index, American Society of Anesthesiologists physical status, use of private insurance, indication for bypass surgery, and SEP on all-cause mortality was analyzed. SEP differed significantly among the 4 race-sex groups, with white men having the highest position (mean = 2.38) and non-white men having the lowest position (mean = -3.02). There was no statistically significant association in 30-day mortality among race-sex groups or with SEP. One-year mortality differed significantly between men and women for the entire cohort (13.7% and 24.1%, respectively; p < 0.01) but not among race groups or SEP.

CONCLUSIONS

Disparities in SEP are not associated with short- or long-term mortality after LEB surgery. Other comorbid risk factors are more important when determining outcomes and should be the focus of interventions to improve outcomes.

Pharmacogenomics of β-adrenergic receptor physiology and response to β-blockade

Myocardial β-adrenergic receptors (βARs) are important in altering heart rate, inotropic state, and myocardial relaxation (lusitropy). The β1AR and β2AR stimulation increases cyclic adenosine monophosphate concentration with the net result of myocyte contraction, whereas β3AR stimulation results in decreased inotropy. Downregulation of β1ARs in heart failure, as well as an increased β3AR activity and density, lead to decreased cyclic adenosine monophosphate production and reduced inotropy. The βAR antagonists are commonly used in patients with coronary artery disease and heart failure; however, perioperative use of βAR antagonists is controversial. Individual patient's response to beta-blocker therapy is an area of intensive research, and apart from pharmacokinetics, pharmacodynamics, and ethnic differences, genetic alterations have become more important in the last 20 years. The most common genetic variants in humans are single nucleotide polymorphisms (SNPs). There are 2 clinically relevant SNPs for the β1AR (Ser49Gly, Arg389Gly), 3 for the β2AR (Arg16Gly, Gln27Glu, Thr164Ile), and 1 for the β3AR (Trp64Arg). Although results are somewhat controversial, generally large datasets have the potential to show a relationship between βAR SNPs and outcomes such as development and progression of heart failure, coronary artery disease, vascular reactivity, hypertension, asthma, obesity, and diabetes. Although βAR SNPs may not directly cause disease, they appear to be risk factors for, and modifiers of, disease and the response to stress and drugs. In the perioperative setting, this has specifically been demonstrated for the Arg389Gly β1AR polymorphism with which patients with the Gly variant had a higher incidence of adverse perioperative events. Knowing that genetic variants play an important role, perioperative medicine will likely change from simple therapeutic intervention to a more personalized way of adrenergic receptor modulation.

Non-ST elevation myocardial infarction: a new pathophysiological concept could solve the contradiction between accepted cause and clinical observations

Non-ST elevation myocardial infarction (NSTEMI) and ST elevation infarction have many differences in their appearance and prognosis. A comprehensive search made us form a new hypothesis that a further cause also existsin NSTEMI: an acute, critical increase in the already existing high microvascular resistance in addition to the subtotal coronary artery occlusion. Various findings and studies can be interpreted only by our hypothesis: hemodynamic findings, ECG changes, autopsy reports and clinical observations (different long-time prognosis and different result of acute revascularization therapy in NSTEMI, similarities of NSTEMI with other clinical symptoms where increased microvascular resistance can be supposed without coronary artery disease).

OBJECTIVE

Despite similarities in the underlying pathologic mechanism non-ST elevation myocardial infarction(NSTEMI) and ST elevation infarction (STEMI) have many differences in their clinical presentation and prognosis.

METHOD

A systematic review of the literature about NSTEMI and the blood supply of the myocardium made us form a hypothesis that a further cause also exists in addition to the accepted cause of NSTEMI (subtotal coronaryartery occlusion): an acute, critical increase in an already existing high intramyocardial microvascular resistance.

EVIDENCE

Knowledge about microcirculation disturbances in ischemic heart disease and development of microcirculation damage can be fitted in our hypothesis. Various findings and studies can be interpreted only by our hypothesis: hemodynamic findings, ECG changes, autopsy reports and clinical observations about NSTEMI. The latest ones involve the different long-time prognosis and different result of acute revascularization therapy in STEMI and NSTEMI. Regarding the repolarization changes on the ECG NSTEMI shows similarities with other clinical symptoms where increased intramyocardial microvascular resistance can be supposed without coronary artery disease: false positive exercise stress test, supraventricular tachycardia, left ventricular strain and conduction disturbances.

CONCLUSION

The acute treatment of NSTEMI should aim to improve the blood inflow to the stiff myocardiumand/or impaired microvascular system and decrease the high microvascular resistance.

The evolving role of preoperative testing in vascular surgery patients: can a little knowledge be dangerous?

It has been traditionally recommended that candidates for vascular surgery receive noninvasive stress perfusion testing risk stratification to help decide which patients may benefit from coronary artery revascularization. Recent clinical trials have contested the efficacy of revascularization in this population as well as the information yield of noninvasive testing. This article reviews a number of these studies that are likely to change our beliefs regarding testing and subsequent interventions as well as evolving role of medical therapy in patients undergoing vascular surgery.

GRADE guidelines 6. Rating the quality of evidence--imprecision

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

β-Blockers in Patients With Intermittent Claudication and Arterial Hypertension

The use of β-receptor blockers in peripheral arterial disease is controversial for their impact on vasomotor tone. The β-blocker nebivolol possesses vasodilating, endothelium-dependent, NO-releasing properties that might be beneficial in peripheral arterial disease. The aim of the study was to evaluate the effects and tolerability of nebivolol in comparison with metoprolol in these patients. A total of 128 patients with intermittent claudication and essential hypertension were included and double-blind randomized to receive 5 mg of nebivolol (N=65) or 95 mg of metoprolol (N=63) once daily. End points were changes in ankle-brachial index, initial and absolute claudication distance, endothelial function assessed by flow-mediated dilatation of the brachial artery, blood pressure, and quality of life using the claudication scale questionnaire. End point analysis was possible in 109 patients (85.2%). After the 48-week treatment period, ankle-brachial index and absolute claudication distance improved significantly in both patient groups ( P <0.05 for both), with no difference across treatments. A significant increase of initial claudication distance was found in the nebivolol group. Adjusted mean change of initial claudication distance was 33.9% after nebivolol ( P =0.003) and 16.6% after metoprolol ( P =0.12) treatment. Quality of life was not influenced by either treatment, and there was no relevant change in flow-mediated dilatation in patients treated with nebivolol or metoprolol ( P =0.16). Both drugs were equally effective in lowering blood pressure. In conclusion, β-blocker therapy was well tolerated in patients with intermittent claudication and arterial hypertension during a treatment period of ≈1 year. In the direct comparison, there was no significant difference between nebivolol and metoprolol.

Metoprolol impairs resistance artery function in mice

Acute β-blockade with metoprolol has been associated with increased mortality by undefined mechanisms. Since metoprolol is a relatively high affinity blocker of β(2)-adrenoreceptors, we hypothesized that some of the increased mortality associated with its use may be due to its abrogation of β(2)-adrenoreceptor-mediated vasodilation of microvessels in different vascular beds. Cardiac output (CO; pressure volume loops), mean arterial pressure (MAP), relative cerebral blood flow (rCBF; laser Doppler), and microvascular brain tissue Po(2) (G2 oxyphor) were measured in anesthetized mice before and after acute treatment with metoprolol (3 mg/kg iv). The vasodilatory dose responses to β-adrenergic agonists (isoproterenol and clenbuterol), and the myogenic response, were assessed in isolated mesenteric resistance arteries (MRAs; ∼200-μm diameter) and posterior cerebral arteries (PCAs ∼150-μm diameter). Data are presented as means ± SE with statistical significance applied at P < 0.05. Metoprolol treatment did not effect MAP but reduced heart rate and stroke volume, CO, rCBF, and brain microvascular Po(2), while concurrently increasing systemic vascular resistance (P < 0.05 for all). In isolated MRAs, metoprolol did not affect basal artery tone or the myogenic response, but it did cause a dose-dependent impairment of isoproterenol- and clenbuterol-induced vasodilation. In isolated PCAs, metoprolol (50 μM) impaired maximal vasodilation in response to isoproterenol. These data support the hypothesis that acute administration of metoprolol can reduce tissue oxygen delivery by impairing the vasodilatory response to β(2)-adrenergic agonists. This mechanism may contribute to the observed increase in mortality associated with acute administration of metoprolol in perioperative patients.

Peak postoperative troponin levels outperform preoperative cardiac risk indices as predictors of long-term mortality after vascular surgery Troponins and postoperative outcomes

BACKGROUND

The utility of postoperative troponins as an independent predictor of long-term mortality after vascular surgery is unknown.

METHODS

One hundred sixty-four consecutive patients underwent vascular surgery and postoperative mortality was determined at 2.5 years. Troponins were drawn within 48 hours postsurgery and the peak levels, defined by the upper reference limit (URL), were categorized as negative (<URL), low positive (≥URL but <3 times the URL), or high positive (≥ 3 times the URL). A logistic regression model comprised all univariate predictors of long-term mortality and included peak troponin levels and the number of the preoperative revised cardiac risks.

RESULTS

Mortality in the high positive (n = 44), low positive (n = 41), and negative (n = 79) troponin groups was 46%, 17%, and 6%, respectively (P < .05). Independent predictors of long-term mortality were peak postoperative troponins (odds ratio [OR], 8.85; 95% confidence interval [CI], 3.29-23.81; P < .001), tissue loss (OR, 2.87; 95% CI, 1.03-8.00; P = .043), and use of statins (OR, 0.19; 95% CI, 0.07-0.49; P < .001). The c index for peak troponin levels was 0.75 (95% CI, 0.68-0.82; P < .01) and outperformed the Revised Cardiac Risk Index for predicting long-term outcomes.

CONCLUSIONS

Among patients undergoing vascular surgery, an elevated postoperative troponin level provides incremental value in predicting long-term outcomes, when compared with standard preoperative cardiac and surgical risks.

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

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

Coronary risk assessment and management options in chronic kidney disease patients prior to kidney transplantation

Cardiovascular disease remains the most important cause of morbidity and mortality among kidney transplant recipients. Nearly half the deaths in transplanted patients are attributed to cardiac causes and almost 5% of these deaths occur within the first year after transplantation. The ideal strategies to screen for coronary artery disease (CAD) in chronic kidney disease patients who are evaluated for kidney transplantation (KT) remain controversial. The American Society of Transplantation recommends that patients with diabetes, prior history of ischemic heart disease or an abnormal ECG, or age ≥50 years should be considered as high-risk for CAD and referred for a cardiac stress test and only those with a positive stress test, for coronary angiography. Despite these recommendations, vast variations exist in the way these patients are screened for CAD at different transplant centers. The sensitivity and specificity of noninvasive cardiac tests in CKD patients is much lower than that in the general population. This has prompted the use of direct diagnostic cardiac catheterization in high-risk patients in several transplant centers despite the risks associated with this invasive procedure. No large randomized controlled trials exist to date that address these issues. In this article, we review the existing literature with regards to the available data on cardiovascular risk screening and management options in CKD patients presenting for kidney transplantation and outline a strategy for approach to these patients.

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.

Preoperative beta-blocker usage: is it really worthy of being a quality indicator?

BACKGROUND

Since 2007, the use of preoperative β-blockers has been used as a quality standard for patients undergoing coronary artery bypass graft surgery. Recent studies have called into question of the benefit of empiric preoperative β-blocker use.

METHODS

Data were extracted from our Society of Thoracic Surgeons certified database for patients undergoing isolated coronary artery bypass graft surgery from 2000 to 2008. We compared the outcomes for patients who received preoperative β-blockers with those of patients who did not.

RESULTS

The study group had 12,855 patients, of whom 7,967 (62.0%) were treated preoperatively with β-blockers. Using propensity matching, we selected two matched groups of 4,474 patients with preoperative β-blocker use and 4,474 not using preoperative β-blockers. In the unmatched cohort, only deep sternal infection (0.3% versus 0.5% without β-blockers; p=0.032), pneumonia (1.9% versus 2.4% without β-blockers; p=0.039), and intraoperative blood usage (37.2% versus 34.1% without β-blockers; p<0.001) reached statistically significant difference. In the matched groups, there was no difference between adverse event rates in patients treated with β-blockers and those who were not. The number of patients requiring intraoperative blood product use was significantly higher among β-blocker-treated patients (p=0.004). Calculating the adjusted odds ratios showed that in the matched groups, the preoperative use of β-blockers was not an independent predictor of mortality.

CONCLUSIONS

A rational for preoperative β-blockade exists. However, as with any medical intervention, its application should be tailored to specific clinical scenarios. With no differences in mortality or morbidity, our findings do not support preoperative β-blockade as a useful quality indicator for coronary artery bypass graft surgery.

[Use of beta blockers in various clinical states]

INTRODUCTION

According to the convincing evidence, a decline in mortality rate has been achieved with beta-blockers in patients with an acute myocardial infarction and in post-infarction follow-up. In fact, there has been a clear reduction of sudden coronary death. The necessary condition for the efficiency of beta-blockers is an early use. They are also a medication of choice for angina after an infarction. The objective of this work was to evaluate the use of beta-blockers after a myocardial infarction in various clinical states and to eliminate doubts concerning their prescription.

BETA BLOCKERS

Even in conditions considered contraindications for administration of beta blockers such as old age, diabetes, non-Q-wave myocardial infarction, peripheral vascular disease, arterial disease, heart insufficiency; ventricular arrhythmias, renal disease, chronic obstructive pulmonary disease, asthma and depression, patients benefit from beta blockers when they are given along with a right choice of the medication and a regular followup of the patient. Preference is given to cardioselective beta blockers in patients with diabetes or lung disease. Beta-blockers do not cause long-term lipid alterations. Therefore, the matter of clinically significant alterations of lipids or blood glucose levels should not need further consideration as a problem of the treatment of diabetics.

DISCUSSION AND CONCLUSION

Investigations have proved that the use of beta-blockers reduces the development of cerebrovascular accidents, heart insufficiency and hypertension. Despite strong arguments and numerous recommendations, beta-blockers have not been accepted to a sufficient extent as an integral part of treatment of acute coronary syndrome and related diseases, to the detriment of many lost lives and in spite of favourable pharmaco-economic aspect.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

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.

A regional quality improvement effort to increase beta blocker administration before vascular surgery

OBJECTIVE

To determine if a regional quality improvement effort can increase beta-blocker utilization prior to vascular surgery and decrease the incidence of postoperative myocardial infarction (POMI).

METHODS

A quality improvement effort to increase perioperative beta blocker utilization was implemented in 2003 at centers participating in the Vascular Study Group of New England (VSGNE). A 90% target was set and feedback given at biannual meetings. Beta blocker utilization (<1 month preoperative versus chronic) and POMI rates were prospectively collected for patients undergoing open abdominal aortic aneurysm (AAA) repair (n = 926) and lower extremity bypass (LEB; n = 2,123) from 2003 through 2008. Predictors of POMI were determined using multivariate logistic regression. Rates of beta blocker administration and POMI were analyzed over time, and across strata of patient risk based on a multivariate model.

RESULTS

Perioperative beta blocker treatment increased from 68% of patients in the first 3 months of 2005 to 88% by the last 3 months of 2008 (P < .001). In 2003, 44% of patients not on chronic beta blockers were treated with preoperative beta blockers; by 2008, 78% of patients not on chronic beta blockers were started perioperatively on these medications (P < .001). Beta blocker utilization increased across all centers and surgeons participating during the study period, and increased in patients of low, medium, and high cardiac risk. However, the rate of POMI did not change over time (5.2% in 2003, 5.5% in 2008; P = .876), although a trend towards lower POMI rate was seen in patients on preoperative beta blockers (4.4% in 2003-2005, 2.6% in 2006-2008; P = .43). In multivariable modeling we found that age >70 (odds ratio [OR], 2.1), positive stress test (OR, 2.2), congestive heart failure (CHF; OR, 1.7), chronic beta blocker administration (OR, 1.7), resting heart rate <70 (OR, 1.8), and diabetes (OR, 1.6) were associated with POMI. Resting heart rate was similar for patients on chronic (67), preoperative (70), and no beta blockers (70; P = .521).

CONCLUSIONS

Our regional quality improvement effort successfully increased perioperative beta blocker utilization. However, this was not associated with reduced rates of POMI or resting heart rate. While this demonstrates the effectiveness of regional quality improvement efforts in changing practice patterns, further work is necessary to more precisely identify those patients who will benefit from beta blockade at the time of vascular surgery.

Preadmission beta-blocker use and 30-day mortality among patients in intensive care: a cohort study

Introduction

Beta-blockers have cardioprotective, metabolic and immunomodulating effects that may be beneficial to patients in intensive care. We examined the association between preadmission beta-blocker use and 30-day mortality following intensive care.

Methods

We identified 8,087 patients over age 45 admitted to one of three multidisciplinary intensive care units (ICUs) between 1999 and 2005. Data on the use of beta-blockers and medications, diagnosis, comorbidities, surgery, markers of socioeconomic status, laboratory tests upon ICU admission, and complete follow-up for mortality were obtained from medical databases. We computed probability of death within 30 days following ICU admission for beta-blocker users and non-users, and the odds ratio (OR) of death as a measure of relative risk using conditional logistic regression and also did a propensity score-matched analysis.

Results

Inclusion of all 8,087 ICU patients in a logistic regression analysis yielded an adjusted OR of 0.82 (95% confidence interval (CI): 0.71 to 0.94) for beta-blocker users compared with non-users. In the propensity score-matched analysis we matched all 1,556 beta-blocker users (19.2% of the entire cohort) with 1,556 non-users; the 30-day mortality was 25.7% among beta-blocker users and 31.4% among non-users (OR 0.74 (95% CI: 0.63 to 0.87)]. The OR was 0.69 (95% CI: 0.54 to 0.88) for surgical ICU patients and 0.71 (95% CI: 0.51 to 0.98) for medical ICU patients. The OR was 0.99 (95% CI: 0.67 to 1.47) among users of non-selective beta-blockers, and 0.70 (95% CI: 0.58 to 0.83) among users of cardioselective beta-blockers.

Conclusions

Preadmission beta-blocker use is associated with reduced mortality following ICU admission.

Screening and management of pretransplant cardiovascular disease

PURPOSE OF REVIEW

Cardiovascular disease is the leading cause of death in kidney transplant recipients. Hence, accurate cardiac risk assessment in potential candidates is an important issue. The purpose of this review is to examine the existing research on the screening and management of pretransplant cardiovascular disease, with an emphasis on defining the optimal approach for asymptomatic high-risk candidates.

RECENT FINDINGS

Randomized controlled trials (RCTs) in the general population demonstrate that prophylactic revascularization in stable patients prior to major noncardiac surgery does not reduce cardiac events or improve survival postoperatively. The benefit of noninvasive stress testing in this population is doubtful based on smaller RCTs and observational studies. Perioperative beta-blockade in intermediate-risk or high-risk candidates appears to be beneficial but acute administration is harmful.

SUMMARY

Investigation for coronary artery disease is warranted for kidney transplant candidates with symptoms of myocardial ischemia. However, there is insufficient evidence to support routine cardiovascular screening in asymptomatic candidates regardless of their cardiac risk factor status. RCTs specifically looking at this issue in renal transplant candidates are a research priority.

Safety of perioperative β-blocker use: how do β-blockers compare in terms of side effects?

INTRODUCTION

In the perioperative setting, there is still a high incidence of adverse cardiac events due to sudden coronary plaque rupture or oxygen supply-demand imbalance. β-Blockers play an important role in preventing these cardiac events. Discussion, however, remains on the side effects accompanying this therapy.

AREAS COVERED

The evidence for perioperative use of β-blockers is summarized in this review in terms of risk reduction, perioperative safety and current clinical use. Furthermore, data on pharmacokinetics, pharmacodynamics and pharmacogenetics are presented.

EXPERT OPINION

In perioperative care, β-blockers are recommended and can be given safely when started early in a low dose, titrated to heart rate. In the future, there could be a place for added perioperative short-acting β-blockers to further optimize heart rate control.

Preoperative cardiac risk management

Approximately 100 million people undergo noncardiac surgery annually worldwide. It is estimated that around 3% of patients undergoing noncardiac surgery experience a major adverse cardiac event. Although cardiac events, like myocardial infarction, are major cause of perioperative morbidity or mortality, its true incidence is difficult to assess. The risk of perioperative cardiac complications depends mainly on two conditions: (1) identified risk factors, and (2) the type of the surgical procedure. On that basis, different scoring systems have been developed in order to accurately assess the perioperative cardiac risk and to improve the patient management. Importantly, patients with estimated high risk should be tested preoperatively by non-invasive cardiac imaging modalities. According to test results, they can proceed directly to planed surgery with the use of cardioprotective drugs (beta-blockers, statins, aspirin), or to myocardial revascularization prior to non-cardiac surgery. In this review, we discuss the role of clinical cardiac risk factors, laboratory measurements, additional non-invasive cardiac testing, and consequent strategies in perioperative management of patients undergoing noncardiac surgery.

Preoperative preparation of geriatric patients

There is a continuous increase in the proportion of elderly patients undergoing surgical procedures. This review will concentrate on selected topics related to elderly care that represent current unresolved and relevant issues for the care of the elderly surgical patient including: aging related organ dysfunction, perioperative risk assessment of geriatrics patient, preoperative optimization and pharmacological support of elderly patient. Additionally, age as a clear risk factor for postoperative cognitive dysfunction is also discussed.

Risk of adverse events after coronary artery bypass graft and subsequent noncardiac surgery

Aims: Coronary artery bypass grafts (CABGs) are increasingly performed in elderly patients. Risk factors and outcomes are poorly described for those undergoing noncardiac surgery within 1 year after CABG. Our objectives were to assess the risk and predictors of major adverse events associated with noncardiac surgery within 1 year after CABG. Methods: In a retrospective review of medical records at Mayo Clinic (Rochester, MN, USA), over a period of 5 years, we identified patients who underwent noncardiac procedures within 1 year post-CABG. All events that occurred within 30 days after noncardiac surgery and deaths within 1 year after noncardiac surgery were considered to be related to CABG. Results: We identified 211 patients; of these, 21 patients had 24 adverse events. Within 1 year, 11 died, and within the first 30 days, three myocardial infarctions, six acute congestive heart failure episodes, three cerebrovascular accidents and one deep vein thrombosis episode had occurred. Predictors of an adverse event included emergency operation (odds ratio: 6.8), ejection fraction less than 45% (p < 0.001) and elevated right ventricular systolic pressure by 40 mmHg or more (p = 0.03). After the noncardiac procedure, patients requiring dialysis (p = 0.02), ventilatory support (p = 0.03) and longer hospital stay (p = 0.03) had greater rates of adverse outcomes. Conclusion: Post-CABG, preoperative ejection fraction less than 45%, right ventricular systolic pressure of 40 mmHg or more, as well as emergent noncardiac surgery, were predictors of adverse outcomes after the noncardiac procedure. Longer postoperative hospital stay, dialysis, as well as ventilatory support, were predictors of adverse outcomes after CABG.

The influence of bisoprolol dose on ADP-induced platelet aggregability in patients on dual antiplatelet therapy

PURPOSE

Dual antiplatelet therapy is recommended after acute coronary syndrome or after percutaneous coronary intervention with coronary stent implantation. Many of the patients on dual antiplatelet therapy receive β-blockers; some of them could have antiaggregatory effect. Bisoprolol is a highly selective adrenoceptor-blocker, which is often used in the settings of percutaneous coronary intervention or acute coronary syndrome in patients on dual antiplatelet therapy. Its antiaggregative effect has not been extensively studied. Therefore, the aim of this study is to investigate the effect of bisoprolol on ADP-induced platelet aggregation in patients on dual antiplatelet therapy.

METHODS

Platelet aggregability has been measured in 100 patients on dual antiplatelet therapy with multiplate analyzer using ADP test in blood samples anticoagulated with heparin. ADP test values have been expressed by arbitrary units/minute. In univariate and multivariate regression analyses, we have investigated the influence of bisoprolol and its dose and also different factors, such as risk factors, concomitant drugs and their dosage, laboratory findings, on ADP test values.

RESULTS

Univariate regression analysis showed significant correlation between the bisoprolol dose and the ADP test value (P=0.046, B=52.55, 95% confidence interval 0.87-104.23), which was also shown in the multivariate regression analysis (P=0.018; B=57.011; 95% confidence interval 10.455-103.567).

CONCLUSION

We have identified a positive correlation between bisoprolol dose and ADP-induced platelet aggregability in patients on dual antiplatelet therapy.

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.

Perioperative pharmacology in elderly patients

PURPOSE OF REVIEW

Populations across the world are getting older and requiring more surgery. Elderly patients present unique challenges to the anesthesiologist and anesthesia-care team. This review addresses some concerns when caring for an elderly patient. Specifically, we discuss postoperative cognitive decline (POCD) and postoperative delirium, perioperative beta-blockade and use of newer drugs, as well as older drugs.

RECENT FINDINGS

POCD has emerged as a new concern for anesthesiologists and their older patients. Several recent studies indicate that POCD is common after noncardiac surgery, with an incidence approaching 30-40% at discharge, although this incidence declines at 3 months. Some data suggest that POCD imparts risk for death. However, there is conflicting evidence. With regard to beta-blocker therapy, there has been growing concern about widespread use of beta-blocker therapy in the perioperative period, especially because such therapy might increase the risk for stroke.

SUMMARY

Elderly patients require focused diligent care. They are particularly sensitive to the many drugs that are administered in the perioperative period. Recent data suggest that POCD is a real concern, but it is unclear what, if anything, can be done to prevent this complication. Beta-blocker therapy is beneficial in select patients but its widespread use cannot be supported.