Perioperative beta-blocker withdrawal and mortality in vascular surgical patients

Intraoperative hypotension in noncardiac surgery patients with chronic beta-blocker therapy: A matched cohort analysis

STUDY OBJECTIVE

To explore the incidence of intraoperative hypotension in patients with chronic beta-blocker therapy, expressed as time spent, area and time-weighted average under predefined mean arterial pressure thresholds.

DESIGN

Retrospective analysis of a prospective observational cohort registry.

SETTING

Patients ≥60 years undergoing intermediate- to high-risk noncardiac surgery with routine postoperative troponin measurements on the first three days after surgery.

PATIENTS

1468 matched sets of patients (1:1 ratio with replacement) with and without chronic beta-blocker treatment.

INTERVENTIONS

None.

MEASUREMENTS

The primary outcome was the exposure to intraoperative hypotension in beta-blocker users vs. non-users. Time spent, area and time-weighted average under predefined mean arterial pressure thresholds (55-75 mmHg) were calculated to express the duration and severity of exposure. Secondary outcomes included incidence of postoperative myocardial injury and thirty-day mortality, myocardial infarction (MI) and stroke. Furthermore, analyses for patient subgroup and beta-blocker subtype were conducted.

MAIN RESULTS

In patients with chronic beta-blocker therapy, no increased exposure to intraoperative hypotension was observed for all characteristics and thresholds calculated (all P > .05). Beta-blocker users had lower heart rate before, during and after surgery (70 vs. 74, 61 vs. 65 and 68 vs. 74 bpm, all P < .001, respectively). Postoperative myocardial injury (13.6% vs. 11.6%, P = .269) and thirty-day mortality (2.5% vs. 1.4%, P = .055), MI (1.4% vs. 1.5%, P = .944) and stroke (1.0% vs 0.7%, P =  .474) rates were comparable. The results were consistent in subtype and subgroup analyses.

CONCLUSIONS

In this matched cohort analysis, chronic beta-blocker therapy was not associated with increased exposure to intraoperative hypotension in patients undergoing intermediate- to high-risk noncardiac surgery. Furthermore, differences in patient subgroups and postoperative adverse cardiovascular events as a function of treatment regimen could not be demonstrated.

Cardiovascular risk management in the peri-operative setting

Peri-operative cardiovascular events occur in up to 3% of patients undergoing non-cardiac surgery. Accurate cardiovascular risk assessment is important in the peri-operative setting, as it allows informed and shared decisions regarding the appropriateness of proceeding with surgery, guides surgical and anaesthetic approaches, and may influence the use of preventive medications and post-operative cardiac monitoring. Quantitative risk assessment may also inform a reconsideration of choosing a more limited lower risk type of surgery, or conservative management. Pre-operative cardiovascular risk assessment starts with clinical assessment and should include an estimate of functional capacity. Specialised cardiac investigations are rarely indicated specifically to assess pre-operative cardiovascular risk. The decision regarding cardiac investigations is influenced by the nature, extent and urgency of surgery. The strategy of performing pre-operative revascularisation to improve post-operative outcomes is not evidence-based and recent international guidelines recommend against this.

Preoperative Management of Cardiovascular Medications: A Society for Perioperative Assessment and Quality Improvement (SPAQI) Consensus Statement

Cardiovascular conditions such as hypertension, arrhythmias, and heart failure are common in patients undergoing anesthesia for surgical or other procedures. Numerous guidelines from various specialty societies offer variable recommendations for the perioperative management of these medications. The Society for Perioperative Assessment and Quality Improvement identified a need to provide multidisciplinary evidence-based recommendations for preoperative medication management. The society convened a group of 13 members with expertise in perioperative medicine and training in anesthesiology or internal medicine. The aim of this consensus effort is to provide perioperative clinicians with guidance on the management of cardiovascular medications commonly encountered during the preoperative evaluation. We used a modified Delphi process to establish consensus. Twenty-one classes of medications were identified: α-adrenergic receptor antagonists, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, angiotensin receptor-neprilysin inhibitors, β-adrenoceptor blockers, calcium-channel blockers, centrally acting sympatholytic medications, direct-acting vasodilators, loop diuretics, thiazide diuretics, potassium-sparing diuretics, endothelin receptor antagonists, cardiac glycosides, nitrodilators, phosphodiesterase-5 inhibitors, class III antiarrhythmic agents, potassium-channel openers, renin inhibitors, class I antiarrhythmic agents, sodium-channel blockers, and sodium glucose cotransportor-2 inhibitors. We provide recommendations for the management of these medications preoperatively.

Hemodynamic depression after carotid surgery: Incidence, risk factors and outcomes

INTRODUCTION

Hemodynamic Depression (HD) characterized by hypotension and bradycardia is a complication of carotid surgery due to direct autonomic stimulation in the carotid sinus. The authors believe the incidence of HD is high and possibly related to major cardiac complications.

METHODS

Analysis of patient records during admissions for carotid surgery between January 2014 and December 2018 in two hospitals. HD was defined as bradycardia or hypotension in the first 24 postoperative hours. Bradycardia was defined as heart rate < 50bpm; hypotension as systolic blood pressure < 90 mmHg, continuous use of vasopressors, or a drop in SBP > 20% compared to preoperative values. Myocardial infarction, stroke, and cardiovascular death were defined as adverse events.

RESULTS

Overall, 237 carotid surgeries (178 endarterectomies, 59 angioplasties) were studied, and the global incidence of HD was 54.4% (hypotension in 50.2%, bradycardia in 11.0%, and hypotension and bradycardia in 6.8%). The independent predictors of HD were asymptomatic carotid stenosis (OR = 1.824; 95% CI 1.014-3.280; p = 0.045), endovascular surgery (OR = 3.319; 95% CI 1.675-6.576; p = 0.001) and intraoperative hypotension or bradycardia (OR = 2.144; 95% CI 1.222-3.762; p = 0.008). Hypotension requiring continuous vasopressor infusion was the only factor independently associated with adverse cardiovascular events (OR = 5.504; 95% CI 1.729-17.529; p = 0.004).

DISCUSSION/CONCLUSION

Incidence of Hemodynamic Depression after carotid surgery is high and independently associated with surgical technique, symptomatic repercussion of the carotid stenosis, and intraoperative hypotension or bradycardia. Hypotension requiring the continuous infusion of vasopressors was independently associated with the occurrence of MACE.

High-Risk Perioperative Medications in the Chinese Elderly Population

Background

Inappropriate perioperative medications among elderly patients increase the risk of adverse events and undermine surgical outcomes. This study aimed to assess the prevalence of high-risk medications in elderly surgical patients and verify the effectiveness of a new-developed high-risk perioperative medications (HRPOMs) list for the elderly.

Methods

A cross-sectional, single-center study was conducted at Jinshan Hospital of Fudan University. A total of 810 elderly surgical patients were included in the study. The HRPOMs list was applied to patients’ data to identify the HRPOMs including chronic medications and medications related to surgery.

Results

A total of 2113 HRPOMs were identified in 810 patients who fulfilled the inclusion criteria. Of these, 1067 (50.5%) involved medications related to surgery, and 982 (46.5%) involved chronic medications. The prevalence of HRPOM exposure, which was defined as at least one HRPOM was 76.3%. Patients that were 70 years or older (adjusted odds ratio [AOR] =2.118, 95% confidence interval [CI], 1.420~3.159), hospitalized over two weeks (AOR =4.192, 95% CI, 1.493~11.771), with more than 2 distinct diagnoses (AOR =3.407, 95% CI, 2.224~5.220) and with 16 or more medications during hospitalization were more likely to be exposed to HRPOMs. Patients who underwent surgeries of Grade IV were at 1.73 increased odds of HRPOM exposure compared with those who received surgeries of Grade III or lower (P=0.071).

Conclusion

HRPOMs are more common in patients of 70 years or older, with 3 or more distinct diagnoses, with 16 or more medications and hospitalized for 15 days or longer. Our study showed the validity of the HRPOMs list in the perioperative medication review for the elderly and may induce further research to reveal the impact of HRPOMs upon the surgical outcomes of the elderly.

Approach and Management of Hypertension After Kidney Transplantation

Hypertension is one of the most common cardiovascular co-morbidities after successful kidney transplantation. It commonly occurs in patients with other metabolic diseases, such as diabetes mellitus, hyperlipidemia, and obesity. The pathogenesis of post-transplant hypertension is complex and is a result of the interplay between immunological and non-immunological factors. Post-transplant hypertension can be divided into immediate, early, and late post-transplant periods. This classification can help clinicians determine the etiology and provide the appropriate management for these complex patients. Volume overload from intravenous fluid administration is common during the immediate post-transplant period and commonly contributes to hypertension seen early after transplantation. Immunosuppressive medications and donor kidneys are associated with post-transplant hypertension occurring at any time point after transplantation. Transplant renal artery stenosis (TRAS) and obstructive sleep apnea (OSA) are recognized but common and treatable causes of resistant hypertension post-transplantation. During late post-transplant period, chronic renal allograft dysfunction becomes an additional cause of hypertension. As these patients develop more substantial chronic kidney disease affecting their allografts, fibroblast growth factor 23 (FGF23) increases and is associated with increased cardiovascular and all-cause mortality in kidney transplant recipients. The exact relationship between increased FGF23 and post-transplant hypertension remains poorly understood. Blood pressure (BP) targets and management involve both non-pharmacologic and pharmacologic treatment and should be individualized. Until strong evidence in the kidney transplant population exists, a BP of <130/80 mmHg is a reasonable target. Similar to complete renal denervation in non-transplant patients, bilateral native nephrectomy is another treatment option for resistant post-transplant hypertension. Native renal denervation offers promising outcomes for controlling resistant hypertension with no significant procedure-related complications. This review addresses the epidemiology, pathogenesis, and specific etiologies of post-transplant hypertension including TRAS, calcineurin inhibitor effects, OSA, and failed native kidney. The cardiovascular and survival outcomes related to post-transplant hypertension and the utility of 24-h blood pressure monitoring will be briefly discussed. Antihypertensive medications and their mechanism of actions relevant to kidney transplantation will be highlighted. A summary of guidelines from different professional societies for BP targets and antihypertensive medications as well as non-pharmacological interventions, including bilateral native nephrectomy and native renal denervation, will be reviewed.

Österreichischer Blutdruckkonsens 2019

Erhöhter Blutdruck bleibt eine Hauptursache von kardiovaskulären Erkrankungen, Behinderung und frühzeitiger Sterblichkeit in Österreich, wobei die Raten an Diagnose, Behandlung und Kontrolle auch in rezenten Studien suboptimal sind. Das Management von Bluthochdruck ist eine häufige Herausforderung für Ärztinnen und Ärzte vieler Fachrichtungen. In einem Versuch, diagnostische und therapeutische Strategien zu standardisieren und letztendlich die Rate an gut kontrollierten Hypertoniker/innen zu erhöhen und dadurch kardiovaskuläre Erkrankungen zu verhindern, haben 13 österreichische medizinische Fachgesellschaften die vorhandene Evidenz zur Prävention, Diagnose, Abklärung, Therapie und Konsequenzen erhöhten Blutdrucks gesichtet. Das hier vorgestellte Ergebnis ist der erste Österreichische Blutdruckkonsens. Die Autoren und die beteiligten Fachgesellschaften sind davon überzeugt, daß es einer gemeinsamen nationalen Anstrengung bedarf, die Blutdruck-assoziierte Morbidität und Mortalität in unserem Land zu verringern.

Implications of the New 2017 American College of Cardiology/American Heart Association Guidelines for Hypertension

Automated validated devices should be used for measuring blood pressure (BP). The 2017 American College of Cardiology (ACC)/American Heart Association (AHA) hypertension guidelines recommend that a systolic BP between 120-129 mmHg with a diastolic BP less than 80 mmHg should be treated with lifestyle measures. These guidelines recommend treatment with lifestyle measures plus BP lowering drugs for secondary prevention of cardiovascular events in persons with clinical cardiovascular disease and an average systolic BP of ≥130 mmHg or an average diastolic BP≥80 mmHg. These guidelines recommend treatment with lifestyle measures plus BP lowering drugs for primary prevention of cardiovascular disease in persons with an estimated 10-year risk of atherosclerotic cardiovascular disease ≥ 10% and an average systolic BP ≥130 mmHg or an average diastolic BP ≥80 mmHg. These guidelines recommend treatment with lifestyle measures plus BP lowering drugs for primary prevention of cardiovascular disease in persons with an estimated 10-year risk of atherosclerotic cardiovascular disease of < 10% and an average systolic BP ≥140 mmHg or an average diastolic BP ≥ 90 mmHg. These guidelines recommend initiating antihypertensive drug therapy with 2 first-line drugs from different classes either as separate agents or in a fixed-dose combination in persons with a BP ≥140/90 mmHg or with a BP > 20/10 mmHg above their BP target. White coat hypertension must be excluded before starting treatment with antihypertensive drugs in persons with hypertension at low risk for atherosclerotic cardiovascular disease. Antihypertensive drug treatment for different disorders is discussed.

Is Compliance With Surgical Care Improvement Project Cardiac (SCIP-Card-2) Measures for Perioperative β-Blockers Associated With Reduced Incidence of Mortality and Cardiovascular-Related Critical Quality Indicators After Noncardiac Surgery?

BACKGROUND

While continuation of β-blockers (BBs) perioperatively has become a national quality improvement measure, the relationship between BB withdrawal and mortality and cardiovascular-related critical quality indicators has not been studied in a contemporary cohort of patients undergoing noncardiac surgery.

METHODS

For this retrospective study, the quality assurance database of a large community-based anesthesiology group practice was used to identify 410,288 surgical cases, 18 years of age or older, who underwent elective or emergent noncardiac surgical procedures between January 1, 2009, and December 31, 2014. Each surgical case that was withdrawn from BBs perioperatively was propensity matched by clinical and surgical characteristics to 4 cases that continued BBs perioperatively. Subsequently, multivariable conditional logistic regression analyses were performed in the matched cohort to determine the extent to which withdrawal of perioperative BBs was independently associated with mortality as the primary outcome and cardiovascular-related critical quality indicators as the secondary outcome (need for vasopressor, electrocardiographic changes requiring treatment, unplanned admission to intensive care unit, postanesthesia care unit stay >2 hours, and a combination of cardiac arrest and myocardial infarction) within 48 hours postoperatively.

RESULTS

Of the 66,755 (16%) cases in the cohort admitted on BB therapy, BBs were withdrawn in 3829 (6%) and continued in 62,926 (94%). Propensity score matching resulted in an analysis cohort of 19,145 cases. Withdrawal of perioperative BBs in the multivariable conditional logistic regression analysis was significantly associated with an increased risk for mortality (odds ratio [OR], 3.61; 95% confidence interval [CI], 1.75-7.35; P = .0003), but a significantly decreased risk for need of blood pressure support requiring vasopressor initiation (OR, 0.84; 95% CI, 0.76-0.92; P = .0003) and extended postanesthesia care unit stay (OR, 0.69; 95% CI, 0.54-0.88; P = .004) within 48 hours after noncardiac surgery.

CONCLUSIONS

Perioperative withdrawal of BBs was associated with increased risk for mortality within 48 hours after noncardiac surgery and with decreased risk for need of vasopressor during the early postoperative period and a shorter stay in the postanesthesia care unit.

The evidence-based preoperative assessment for the otolaryngologist

There is a narrow window of opportunity between surgical scheduling and the operative date to optimize patients for an elective surgical procedure. Traditionally, preoperative care has involved extended routine testing batteries with intermittent referrals for medical clearance. These traditions are costly, inefficient, and yield no clear reduction in perioperative morbidity and mortality. Evidence, which has evolved over the past decade, suggests that optimal preoperative care requires a patient-centric, personalized, and often multidisciplinary approach. We present an up-to-date overview of this literature with a focus on the otolaryngologic surgical population. An algorithmic approach to preoperative patient assessment is also proposed in hopes of both optimizing patient outcome and streamlining routine clinical workflow. Laryngoscope, 130:38-44, 2020.

Elevated preoperative heart rate associated with increased risk of cardiopulmonary complications after resection for lung cancer

BACKGROUND

The study aimed to assess whether preoperative resting heart rate could be a risk factor for cardiopulmonary complications (CPCs) after lung cancer resection.

METHODS

Eligible consecutive patients who underwent resection surgery for non-small cell lung cancer (NSCLC) at Ningbo NO.2 Hospital between May, 2010 and July, 2015 were included. The demographic, clinical characteristics and laboratory parameters were compared in patients with or without CPCs within postoperative 30 days. The multivariate logistic regression analysis was used to analyze the association between CPCs and risk factors. Receiver operating characteristic (ROC) curve analysis was utilized for the predictive role of preoperative resting heart rate for CPCs.

RESULTS

One hundred eighty participants were enrolled into the final analysis and 42 of them had an established diagnosis of CPCs within postoperative 30 days. Elevated preoperative resting heart rate was an independent risk factor for postoperative CPCs (OR: 4.48, 95% CI: 1.17-18.42, P = 0.021) by the multivariate logistic regression analysis. ROC curve analysis indicated elevated resting heart rate as a predictor for CPCs with a cut-off value of 86 beats/min (AUC: 0.813, specificity: 80.95%, sensitivity: 72.46%, P < 0.001).

CONCLUSIONS

Elevated preoperative resting heart rate was associated with an increased risk of postoperative CPCs in patients after resection for lung cancer.

Antipsychotic-Induced Dopamine Supersensitivity Psychosis: Pharmacology, Criteria, and Therapy

The first-line treatment for psychotic disorders remains antipsychotic drugs with receptor antagonist properties at D2-like dopamine receptors. However, long-term administration of antipsychotics can upregulate D2 receptors and produce receptor supersensitivity manifested by behavioral supersensitivity to dopamine stimulation in animals, and movement disorders and supersensitivity psychosis (SP) in patients. Antipsychotic-induced SP was first described as the emergence of psychotic symptoms with tardive dyskinesia (TD) and a fall in prolactin levels following drug discontinuation. In the era of first-generation antipsychotics, 4 clinical features characterized drug-induced SP: rapid relapse after drug discontinuation/dose reduction/switch of antipsychotics, tolerance to previously observed therapeutic effects, co-occurring TD, and psychotic exacerbation by life stressors. We review 3 recent studies on the prevalence rates of SP, and the link to treatment resistance and psychotic relapse in the era of second-generation antipsychotics (risperidone, paliperidone, perospirone, and long-acting injectable risperidone, olanzapine, quetiapine, and aripiprazole). These studies show that the prevalence rates of SP remain high in schizophrenia (30%) and higher (70%) in treatment-resistant schizophrenia. We then present neurobehavioral findings on antipsychotic-induced supersensitivity to dopamine from animal studies. Next, we propose criteria for SP, which describe psychotic symptoms and co-occurring movement disorders more precisely. Detection of mild/borderline drug-induced movement disorders permits early recognition of overblockade of D2 receptors, responsible for SP and TD. Finally, we describe 3 antipsychotic withdrawal syndromes, similar to those seen with other CNS drugs, and we propose approaches to treat, potentially prevent, or temporarily manage SP.

Beta-blockers in noncardiac surgery: Did observational studies put us back on safe ground?

Based on landmark trials, international guidelines had for years promoted the use of beta-blockers in the setting of non-cardiac surgery. In 2011, concerns were raised regarding the integrity of some of the landmark trials, as the Dutch Erasmus Medical Center found some of them to be scientifically incorrect. Based on the remaining studies that were to be trusted, investigations showed that, in contrast to prior beliefs, the widespread use of perioperative beta-blockers might be harmful. A call for further investigations into the matter ushered in several observational studies evaluating the safety of perioperative beta-blocker therapy in specific patient subgroups. Within this review, we discuss important aspects for making these decisions, and compare the major observational studies and specific estimates of risk in subgroups of interest. We conclude that patients at high risk with heavy co-morbidities, such as heart failure, may benefit from beta-blocker therapy, whereas low-risk patients, such as patients with uncomplicated hypertension, may be at increased risk with beta-blocker therapy. We provide a critical review of current perioperative guidelines in view of the new observational data, suggesting that the recommended schematics, such as the Revised Cardiac Risk Index, for risk stratification of patients in this setting may be suboptimal. Further, we provide discussions of other aspects, including risk of sepsis, type of beta-blocker, and the potential of perioperative beta-blocker withdrawal, which may be important in guiding future studies. Summarising the current evidence, we argue that, after a precarious decade, we may just now, be back on safe ground.

Implications of the New National Guidelines for Hypertension

Automated validated devices should be used for measuring blood pressure (BP). A systolic BP between 120 and 129 mm Hg with a diastolic BP < 80 mm Hg should be treated by lifestyle measures. Lifestyle measures plus BP lowering drugs should be used for secondary prevention of recurrent cardiovascular disease (CVD) events in persons with clinical CVD (coronary heart disease, congestive heart failure, and stroke) and an average systolic BP of ≥130 mm Hg or an average diastolic BP ≥ 80 mm Hg. Lifestyle measures plus BP lowering drugs should be used for primary prevention of CVD in persons with an estimated 10-year risk of atherosclerotic CVD ≥ 10% and an average systolic BP ≥130 mm Hg or an average diastolic BP ≥ 80 mm Hg. Lifestyle measures plus BP lowering drugs should be used for primary prevention of CVD in persons with an estimated 10-year risk of atherosclerotic CVD of <10% and an average systolic BP ≥ 140 mm Hg or an average diastolic BP ≥ 90 mm Hg. Initiate antihypertensive drug therapy with 2 first-line drugs from different classes either as separate agents or in a fixed-dose combination in persons with a BP ≥ 140/90 mm Hg or with a BP > 20/10 mm Hg above their BP target. White coat hypertension must be excluded before initiating treatment with antihypertensive drugs in persons with hypertension at low risk for atherosclerotic CVD. Antihypertensive drug treatment for different disorders is discussed.

Cardiac Evaluation and Monitoring of Patients Undergoing Noncardiac Surgery

Surgical management of disease has a tremendous impact on our health system. Millions of people worldwide undergo surgeries every year. Cardiovascular complications in the perioperative period are one of the most common events leading to increased morbidity and mortality. Although such events are very small in number, they are associated with a high mortality rate making it essential for physicians to understand the importance of perioperative cardiovascular risk assessment and evaluation. Its involves a detailed process of history taking, patient's medical profile, medications being used, functional status of the patient, and knowledge about the surgical procedure and its inherent risks. Different risk assessment tools and calculators have also been developed to aid in this process, each with their own advantages and limitations. After such a comprehensive evaluation, a physician will be able to provide a risk assessment or it may all lead to further testing if it is believed that a change in management after such testing will help to reduce perioperative morbidity and mortality. There is extensive literature on the significance of multiple perioperative testing modalities and how they can change management. The purpose of our review is to provide a concise but comprehensive analysis on all such aspects of perioperative cardiovascular risk assessment for noncardiac surgeries and provide a basic methodology toward such assessment and decision making.

Post-procedural Care in Interventional Radiology: What Every Interventional Radiologist Should Know-Part I: Standard Post-procedural Instructions and Follow-Up Care

Interventional radiology (IR) has evolved into a full-fledged clinical specialty with attendant patient care responsibilities. Success in IR now requires development of a full clinical practice, including consultations, inpatient admitting privileges, and an outpatient clinic. In addition to technical excellence and innovation, maintaining a comprehensive practice is imperative for interventional radiologists to compete successfully for patients and referral bases. A structured approach to periprocedural care, including routine follow-up and early identification and management of complications, facilitates efficient and thorough management with an emphasis on quality and patient safety.

Safety of intravenous metoprolol use in unmonitored wards: a single-centre observational study

BACKGROUND AND AIM

This study aims to examine and quantify the risks associated with the use of intravenous metoprolol on unmonitored wards.

METHOD

This study was a retrospective single-centre observational study from 1 January 2009 to 31 December 2013. The study hospital was a 415-bed, private hospital in Melbourne, Victoria. The study population was all patients who received intravenous metoprolol on an unmonitored ward. The primary outcome measure was the rate of serious adverse events (SAE), defined as a complication of intravenous metoprolol resulting in transfer to a critical-care environment, a medical emergency team call or death.

RESULTS

Six hundred and nine patients received a total of 8260 doses of intravenous metoprolol. Seven cases were identified with a SAE deemed possibly related to beta-blocker use and there was one death. All SAE were hypotension, giving an overall rate of hypotension of 7/609 or 1.1% (95% confidence interval (CI), 0.5 to 2.4%) with a rate per dose delivered of 0.8/1000 doses (95% CI 0.3 to 1.7). The death occurred in a 94-year-old woman with abdominal sepsis. After case file review, consensus opinion deemed this to be unrelated to intravenous metoprolol.

CONCLUSION

The use of intravenous metoprolol on unmonitored wards appears to be safe. The complication rate was low, suggesting that this may be a sensible approach to the management of in-hospital populations at risk of beta-blocker withdrawal.

Peri-operative cardiac protection for non-cardiac surgery

Cardiovascular complications are an important cause of morbidity and mortality after non-cardiac surgery. Pre-operative identification of high-risk individuals and appropriate peri-operative management can reduce cardiovascular risk. It is important to continue chronic beta-blocker and statin therapy. Statins are relatively safe and peri-operative initiation may be beneficial in high-risk patients and those scheduled for vascular surgery. The pre-operative introduction of beta-blockers reduces myocardial injury but increases rates of stroke and mortality, possibly due to hypotension. They should only be considered in high-risk patients and the dose should be titrated to heart rate. Alpha-2 agonists may also contribute to hypotension. Aspirin continuation can increase the risk of major bleeding and offset the benefit of reduced myocardial risk. Contrary to the initial ENIGMA study, nitrous oxide does not seem to increase the risk of myocardial injury. Volatile anaesthetic agents and opioids have been shown to be cardioprotective in animal laboratory studies but these effects have, so far, not been conclusively reproduced clinically.

A case-cohort study of postoperative myocardial infarction: impact of anemia and cardioprotective medications

OBJECTIVE

Postoperative myocardial infarction (poMI) is a serious and costly complication. Multiple risk factors for poMI are known, but the effect of anemia and cardioprotective medications have not been defined in real-world surgical practice.

METHODS

Patients undergoing inpatient elective surgery were assessed at 17 hospitals from 2008 to 2011 for the occurrence of poMI (American Heart Association definition). Non-MI control patients were chosen randomly on the basis of case type. Descriptive, univariable, and multivariable statistical analysis were performed for primary outcomes of poMI and death at 30 days.

RESULTS

Compared with controls (N = 304), patients with poMI (N = 222) were older (72 ± 11 vs 60 ± 17 years, P < .0001), had a lesser preoperative hematocrit (37 ± 6 vs 39 ± 5, P < .0001), more often were smokers, had a preoperative T-wave abnormality (21% vs 9%, P < .0001), and had a preoperative stress test with a fixed deficit (26% vs 3%; P < .001). Preoperative factors associated with poMI included peripheral vascular disease (odds ratio 2.6; 95% confidence interval 1.3-5.3), tobacco use (1.7; 1.01-2.9), history of percutaneous coronary angioplasty (2.8; 1.6-5.0), and age (1.05; 1.03-1.07), whereas hematocrit >35 (0.51; 0.32-0.82) and preoperative acetylsalicylic acid, ie, aspirin (0.59; 0.4-0.97) were protective. Preoperative β-blockade, statin, and use of angiotensin-converting enzyme inhibitors were not associated with lesser rates of poMI. Non-MI complication rates were 23-fold greater in the poMI group compared with the control group (P < .0001). Mortality with poMI within 30 days was 11% compared with 0.3% in non-MI control patients (P < .0001). In patients with poMI, factors independently associated with death included use of epidurals (3.5; 1.07-11.4) and bleeding (4.2; 1.1-16), whereas preoperative use of aspirin (0.29; 0.1-0.88), and postoperative β-blockade (0.18; 0.05-0.63) were protective. Cardiac catheterization, percutaneous coronary intervention, or coronary artery bypass grafting after poMI was performed in 34% of those alive and 20% of those who died (P = .16).

CONCLUSION

In the current era, poMI patients have a markedly increased risk of death. This risk is decreased with preoperative use of acetylsalicylic acid and post MI β-blockade. Further study is warranted to explore the role of anemia and cardiac interventions after poMI.

Optimal perioperative medical management of the vascular surgery patient

Perioperative medical management of patients undergoing vascular surgery can be challenging because they represent the surgical population at highest risk. β-Blockers should be continued perioperatively in patients already taking them preoperatively. Statins may be used in the perioperative period in patients who are not on statin therapy preoperatively. Institutional guidelines should be used to guide insulin replacement. Recent research suggests that measurement of troponins may provide some risk stratification in clinically stable patients following vascular surgery. Multimodal pain therapy including nonopioid strategies is necessary to improve the efficacy of pain relief and decrease the risk of side effects and complications.