Effect of aspirin in vascular surgery in patients from a randomized clinical trial (POISE-2)

Safety of laparoscopic inguinal hernia repair in the setting of antithrombotic therapy

INTRODUCTION

There are a paucity of data regarding the safety of laparoscopic inguinal hernia repair in patients on antiplatelet and anticoagulant therapy (APT/ACT). We aim to compare the postoperative outcomes of laparoscopic (LIHR) vs. open repair of inguinal hernias (OIHR) in patients on APT/ACT.

METHOD

We conducted a retrospective cohort study using the Vizient Clinical DataBase. We included adults receiving APT/ACT who underwent outpatient, elective, and primary inguinal hernia repair between 2017 and 2019. Subgroup analysis was performed on patients receiving aspirin, non-aspirin antiplatelet, and anticoagulant therapy. Mixed-effects logistic regression was used to assess both the effect of APT/ACT on the probability of receiving LIHR vs OIHR and their respective outcomes.

RESULT

A total of 142,052 repairs were included, of which 21,441 (15%) were performed on patients receiving APT/ACT. Mean age was 69 years (± 10.5) and 93% were male. 19% of hernias were bilateral. 40% of operations were performed at teaching hospitals. On multivariable analysis, patients on non-aspirin antiplatelet or anticoagulant therapy were more likely to receive an open procedure (Odds Ratio (OR) = 1.2; 95% Confidence Intervals (CI) [1.1, 1.4] and OR = 1.4; CI [1.3, 1.5], respectively). LIHR was associated with a lower rate of length of stay > 1 day (OR = 0.65; CI [0.5, 0.9]). Rates of 30-day postoperative hematoma, transfusions, stroke, myocardial infarction, deep venous thrombosis, pulmonary embolism, readmission, and emergency department visits were similar between the two operative approaches.

CONCLUSION

Patients on APT/ACT represent a substantial proportion of those undergoing inguinal hernia repair. Non-aspirin antiplatelet or anticoagulant therapy are independent predictors of choosing an open repair. Laparoscopic repair appears to be safe in patients receiving APT/ACT under current perioperative management patterns.

Antithrombotic Therapy for Aortic Aneurysms: A Systematic Review and Meta-Analysis

OBJECTIVES

The role of antithrombotic therapy in the management of aortic and peripheral aneurysms is unclear. This systematic review and meta-analysis aimed to assess the impact of antithrombotics on clinical outcomes for aortic and peripheral aneurysms.

METHODS

Medline, Embase, and CENTRAL databases were searched. Randomised controlled trials and observational studies investigating the effect of antithrombotic therapy on clinical outcomes for patients with any aortic or peripheral artery aneurysm were included.

RESULTS

Fifty-nine studies (28 with antiplatelet agents, 12 anticoagulants, two intra-operative heparin, and 16 any antithrombotic agent) involving 122 102 patients were included. Abdominal aortic aneurysm (AAA) growth rate was not significantly associated with the use of antiplatelet therapy (SMD -0.36 mm/year; 95% CI -0.75 - 0.02; p = .060; GRADE certainty: very low). Antithrombotics were associated with increased 30 day mortality for patients with AAAs undergoing intervention (OR 2.30; 95% CI 1.51 - 3.51; p < .001; GRADE certainty: low). Following intervention, antiplatelet therapy was associated with reduced long term all cause mortality (HR 0.84; 95% CI 0.76 - 0.92; p < .001; GRADE certainty: moderate), whilst anticoagulants were associated with increased all cause mortality (HR 1.64; 95% CI 1.14 - 2.37; p = .008; GRADE certainty: very low), endoleak within three years (OR 1.99; 95% CI 1.10 - 3.60; p = .020; I² = 60%; GRADE certainty: very low), and an increased re-intervention rate at one year (OR 3.25; 95% CI 1.82 - 5.82; p < .001; I² = 35%; GRADE certainty: moderate). Five studies examined antithrombotic therapy for popliteal aneurysms. Meta-analysis was not possible due to heterogeneity.

CONCLUSIONS

There was a lack of high quality data examining antithrombotic therapy for patients with aneurysms. Antiplatelet therapy was associated with a reduction in post-intervention all cause mortality for AAA, whilst anticoagulants were associated with an increased risk of all cause mortality, endoleak, and re-intervention. Large, well designed trials are still required to determine the therapeutic benefits of antithrombotic agents in this setting.

Preoperative evaluation and perioperative management of patients undergoing major vascular surgery

Patients undergoing major vascular surgery have an increased risk of perioperative major adverse cardiovascular events (MACE). Accordingly, in this population, it is of particular importance to appropriately risk stratify patients' risk for these complications and optimize risk factors prior to surgical intervention. Comorbidities that portend a higher risk of perioperative MACE include coronary artery disease, heart failure, left-sided valvular heart disease, and significant arrhythmic burden. In this review, we provide a current approach to risk stratification prior to major vascular surgery and describe the strengths and weaknesses of different cardiac risk indices; discuss the role of noninvasive and invasive cardiac testing; and review perioperative pharmacotherapies.

Association of PeriOPerative Aspirin-ResisTance and CardioVascular Outcome (POPART- CVO) - a prospective non-interventional cohort study

OBJECTIVES

New onset of aspirin-resistance during surgery, known as perioperative aspirin-resistance, is observed in up to 30% of vascular surgery patients and is associated with post-OP myocardial damage; questioning aspirin effectiveness towards perioperative cardiovascular events. The objective of this study was to prospectively evaluate whether perioperative aspirin-resistance in vascular surgery is associated with adverse cardiovascular outcome.

DESIGN AND METHODS

Based on a sample size calculation, 194 adult elective vascular or endovascular surgery patients receiving aspirin were analyzed in this prospective, single-centered, non-interventional cohort study. Platelet function was measured before surgery, one hour after incision, four hours postoperatively, and on the morning of the first and second postoperative days using the Multiplate® analyzer. The primary outcome was Myocardial Injury after Non-Cardiac Surgery (MINS). Secondary outcomes included major bleeding, admission to intensive care unit, length of hospital stay, and Major Adverse Cardiac and Cerebrovascular Events. Subgroup analyses were performed for patients with different cardiovascular risk and for patients who underwent endovascular surgery.

RESULTS

Perioperative aspirin-resistance was observed in 27.8% of patients but was not associated with MINS (27.8% vs. 32.1%, aspirin-resistance vs. no aspirin-resistance, OR 0.812, 95% CI [0.406;1.624], p=.555) or with any of the secondary endpoints (all p>.05). In nine of the ten subgroup analyses, aspirin-resistance was not associated with a difference in MINS rate. However, in patients with a low cardiovascular risk profile (RCRI 0-2), MINS occurred more frequently in patients without aspirin-resistance (p=.049).

CONCLUSIONS

We confirmed previous reports demonstrating that perioperative aspirin-resistance is frequent in patients undergoing vascular or endovascular surgery. However, in patients who continue aspirin throughout the perioperative period, aspirin-resistance is a phenomenon, that does not appear to be related to MINS. Measuring perioperative platelet function using the Multiplate® analyzer with the intention to identify and potentially prevent or treat perioperative aspirin-resistance seems to be dispensable.

Aggressive intraoperative warming versus routine thermal management during non-cardiac surgery (PROTECT): a multicentre, parallel group, superiority trial

BACKGROUND

Moderate intraoperative hypothermia promotes myocardial injury, surgical site infections, and blood loss. Whether aggressive warming to a truly normothermic temperature near 37°C improves outcomes remains unknown. We aimed to test the hypothesis that aggressive intraoperative warming reduces major perioperative complications.

METHODS

In this multicentre, parallel group, superiority trial, patients at 12 sites in China and at the Cleveland Clinic in the USA were randomly assigned (1:1) to receive either aggressive warming to a target core temperature of 37°C (aggressively warmed group) or routine thermal management to a target of 35·5°C (routine thermal management group) during non-cardiac surgery. Randomisation was stratified by site, with computer-generated, randomly sized blocks. Eligible patients (aged ≥45 years) had at least one cardiovascular risk factor, were scheduled for inpatient non-cardiac surgery expected to last 2-6 h with general anaesthesia, and were expected to have at least half of the anterior skin surface available for warming. Patients requiring dialysis and those with a body-mass index exceeding 30 kg/m² were excluded. The primary outcome was a composite of myocardial injury (troponin elevation, apparently of ischaemic origin), non-fatal cardiac arrest, and all-cause mortality within 30 days of surgery, as assessed in the modified intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT03111875.

FINDINGS

Between March 27, 2017, and March 16, 2021, 5056 participants were enrolled, of whom 5013 were included in the intention-to-treat population (2507 in the aggressively warmed group and 2506 in the routine thermal management group). Patients assigned to aggressive warming had a mean final intraoperative core temperature of 37·1°C (SD 0·3) whereas the routine thermal management group averaged 35·6°C (SD 0·3). At least one of the primary outcome components (myocardial injury after non-cardiac surgery, cardiac arrest, or mortality) occurred in 246 (9·9%) of 2497 patients in the aggressively warmed group and in 239 (9·6%) of 2490 patients in the routine thermal management group. The common effect relative risk of aggressive versus routine thermal management was an estimated 1·04 (95% CI 0·87-1·24, p=0·69). There were 39 adverse events in patients assigned to aggressive warming (17 of which were serious) and 54 in those assigned to routine thermal management (30 of which were serious). One serious adverse event, in an aggressively warmed patient, was deemed to be possibly related to thermal management.

INTERPRETATION

The incidence of a 30-day composite of major cardiovascular outcomes did not differ significantly in patients randomised to 35·5°C and to 37°C. At least over a 1·5°C range from very mild hypothermia to full normothermia, there was no evidence that any substantive outcome varied. Keeping core temperature at least 35·5°C in surgical patients appears sufficient.

FUNDING

3M and the Health and Medical Research Fund, Food and Health Bureau, Hong Kong.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Perioperative continuation of aspirin, oral anticoagulants or bridging with therapeutic low-molecular-weight heparin does not increase intraoperative blood loss and blood transfusion rate in cystectomy patients: an observational cohort study

OBJECTIVE

To assess if uninterrupted anticoagulant agents' administration affects blood loss and blood transfusion during open radical cystectomy (RC) and urinary diversion.

PATIENTS AND METHODS

We conducted an observational single-centre cohort study of a consecutive series of 1430 RC patients, between 2000 and 2020. Blood loss was depicted according to body weight and duration of surgery (mL/kg/h), and blood transfusion. The group 'with anticoagulant agents' was considered if surgery was performed with uninterrupted low-dose aspirin (ASS), oral anticoagulants (OAC) with an international normalised ratio (INR) goal of 2-2.5 or bridging with therapeutic low-molecular-weight heparin (LMWH). Outcomes were intraoperative blood loss, blood transfusion rate (separately analysed if administered within 24 h perioperatively or >24 h after surgery) and the 90-day major adverse cardiac events (MACE) rate. We used propensity score (PS)-matching analysis to adjust for imbalances between groups with or without anticoagulant agents.

RESULTS

The PS-matched median (interquartile range [IQR]) blood loss was 2.10 (1.50-2.94) mL/kg/h in patients with anticoagulant agents vs 2.11 (1.47-2.94) mL/kg/h without anticoagulant agents (Padj  > 0.99). The PS-matched blood transfusion rates were 26.2% vs 35.1% (Padj  = 0.875) within 24 h perioperatively and 57.0% vs 55.0% (Padj  = 0.680) if administered >24 h postoperatively. A sub-analysis of the three different anticoagulant agents could not detect any significance between ASS, OAC, or LMWH. The PS-matched incidence of MACE was 9.1% in the group with anticoagulant agents and 8.1% in those without anticoagulant agents (Padj  > 0.99). Limitations include selection bias and retrospective analysis from prospectively assessed data.

CONCLUSIONS

Perioperative continuation of ASS, uninterrupted OAC with low INR goal or bridging with LMWH had no impact on blood loss and transfusion rate in RC patients. Therefore, there might be no compulsory need for discontinuation of anticoagulant agents.

Perioperative Care of Patients at High Risk for Stroke During or After Non-cardiac, Non-neurological Surgery: 2020 Guidelines From the Society for Neuroscience in Anesthesiology and Critical Care

Perioperative stroke is associated with considerable morbidity and mortality. Stroke recognition and diagnosis are challenging perioperatively, and surgical patients receive therapeutic interventions less frequently compared with stroke patients in the outpatient setting. These updated guidelines from the Society for Neuroscience in Anesthesiology and Critical Care provide evidence-based recommendations regarding perioperative care of patients at high risk for stroke. Recommended areas for future investigation are also proposed.

Evolution of Clinical Thinking and Practice Regarding Aspirin: What Has Changed and Why?

Aspirin (ASA) is the original antiplatelet agent. Its routine use, long unquestioned for both primary and secondary prevention in cardiovascular disease, is under increasing scrutiny as the risk:benefit balance for ASA becomes less clear and other disease- and risk-modifying approaches are validated. It can be viewed as a significant advance in evidence-based medicine that the use of an inexpensive, readily available, long-validated therapy is being questioned in large, rigorous trials. In this overview we present the important questions surrounding a more informed approach to ASA therapy: duration of therapy, assessment of net clinical benefit, and timing of start and stop strategies. We also consider potential explanations for "breakthrough" thrombosis when patients are on ASA therapy. Other manuscripts in this Supplement address the specifics of primary prevention, secondary prevention, triple oral antithrombotic therapy, and the future of ASA in cardiovascular medicine.

Preventing Myocardial Injury Following Non-Cardiac Surgery: A Potential Role for Preoperative Antioxidant Therapy with Ubiquinone

Over 240 million non-cardiac operations occur each year and are associated with a 15-20% incidence of adverse perioperative cardiovascular events. Unfortunately, preoperative therapies that have been useful for chronic ischemic heart diseases, such as coronary artery revascularization, antiplatelet agents, and beta-blockers have failed to improve outcomes. In a pre-clinical swine model of ischemic heart disease, we showed that daily administration of ubiquinone (coenzyme Q₁₀, CoQ₁₀) enhances the antioxidant status of mitochondria within chronically ischemic heart tissue, potentially via a PGC1α-dependent mechanism. In a randomized controlled trial, among high-risk patients undergoing elective vascular surgery, we showed that NT Pro-BNP levels are an important means of risk-stratification during the perioperative period and can be lowered with administration of CoQ₁₀ (400 mg/day) for 3 days prior to surgery. The review provides background information for the role of oxidant stress and inflammation during high-risk operations and the potential novel application of ubiquinone as a preoperative antioxidant therapy that might reduce perioperative adverse cardiovascular outcomes.

A Comprehensive Update on Aspirin Management During Noncardiac Surgery

Aspirin is considered critical lifelong therapy for patients with established cardiovascular (CV) disease (including coronary artery, cerebrovascular, and peripheral arterial diseases) and is consequently one of the most widely used medications worldwide. However, the indications for aspirin use continue to evolve and recent trials question its efficacy for primary prevention. Although one third of patients undergoing noncardiac surgery and at risk for a major adverse CV event receive aspirin perioperatively, uncertainty still exists about how aspirin should be optimally managed in this context, and significant practice variability remains. Recent trials suggest that the risks of continuing aspirin during the perioperative period outweigh the benefits in many cases, but data on patients with high CV risk remain limited. We performed a comprehensive PubMed and Medline literature search using the following keywords: aspirin, aspirin withdrawal, perioperative, coronary artery disease, cerebrovascular disease, peripheral artery disease, and CV disease; we manually reviewed all relevant citations for inclusion. Patients taking aspirin for the primary prevention of CV disease should likely discontinue it during the perioperative period, especially when there is a high risk of bleeding. Patients with established CV disease but without a coronary stent should likely continue aspirin during the perioperative period unless undergoing closed-space surgery. Patients with a history of coronary stenting also likely need aspirin continuation throughout the perioperative period for nonclosed space procedures. Perioperative clinicians need to balance the risks of ceasing aspirin before surgery against its continuation during the perioperative interval using a patient-specific strategy. The guidance on decision-making with regard to perioperative aspirin cessation or continuation using currently available clinical data from studies in high-risk patients along with nonclinical aspirin studies is conflicting and does not enable a simplified or unified answer. However, pertinent guidelines on CV disease management provide a basic framework for aspirin management, and large trial findings provide some insight into the safety of perioperative aspirin cessation in some contexts, although uncertainty on perioperative aspirin still exists. This review provides an evidence-based update on perioperative aspirin management in patients undergoing noncardiac surgery with a focus on recommendations for perioperative clinicians on continuing versus holding aspirin during this context.

NT-Pro BNP Predicts Myocardial Injury Post-vascular Surgery and is Reduced with CoQ10: A Randomized Double-Blind Trial

BACKGROUND

NT-Pro BNP levels provide incremental value in perioperative risk assessment prior to major noncardiac surgery. Whether they can be pharmacologically modified in patients prior to an elective vascular operation is uncertain.

METHODS

A double-blind, randomized controlled trial was implemented at a single institution. Patients were screened during their preoperative vascular clinic appointment and randomly assigned to CoQ₁₀ (400 mg per day) versus Placebo for 3 days prior to surgery. Biomarkers, including NT-Pro BNP, troponin I and C-reactive protein were obtained prior to and following surgery for up to 48 hours. The primary endpoint was postoperative NT-Pro BNP levels, and secondary endpoint measures included myocardial injury, defined by an elevated cardiac troponin level and length of stay.

RESULTS

One hundred and twenty-three patients were randomized to receive either CoQ₁₀ (N = 62) versus Placebo (N = 61) for 3 days before vascular surgery. Preoperative cardiac risks included ischemic heart disease (N = 52), CHF (N = 12), stroke (N = 23), and diabetes mellitus (N = 48) and the planned vascular procedures were infrainguinal (N = 78), carotid (N = 36), and intraabdominal (N = 9). There were no intergroup differences in these clinical variables. NT-Pro BNP levels (median; IQs) in the CoQ₁₀ and Placebo groups were 179 (75-347) and 217 (109-585) pg/ml, respectively, (P = 0.08) preoperatively, and 397 (211-686) and 591 (288-1,433) pg/ml respectively, (P = 0.01) at 24 hours following surgery. Patients with an elevated NT-Pro BNP had a higher incidence of myocardial injury, (58% vs. 20%; P < 0.01) and a longer hospital stay (4.4 ± 3.8 vs. 2.8 ± 3.2 days; P < 0.02) compared with individuals without an elevated NT-Pro BNP level.

CONCLUSIONS

NT-Pro BNP levels predict adverse events post-vascular surgery and are lowered in those patients assigned to preoperative administration of CoQ₁₀.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT03956017. Among patients undergoing elective vascular surgery, 123 patients were randomized to either CoQ₁₀ (400 mg/day) versus placebo for three days preoperatively. NT-Pro BNP levels (median; IQs) in the CoQ₁₀ and Placebo groups were 179 (75-347) and 217 (109-585) pg/ml, respectively, (P = 0.08) preoperatively, and 397 (211-686) and 591 (288-1,433) pg/ml, respectively, (P = 0.01) post-surgery. Patients with an elevated NT-Pro BNP had a higher incidence of myocardial injury (58% vs. 20%; P < 0.01) and a longer hospital stay (4.4 ± 3.8 vs. 2.8 ± 3.2 days; P < 0.02) compared with individuals without an NT-Pro BNP elevation. In conclusion, BNP predicts adverse outcomes and can be reduced with preoperative CoQ₁₀.

Management of the patient presenting with anaemia in the preoperative setting

Preoperative anaemia is common, seen in a third of patients before major surgery. Both preoperative anaemia and blood transfusion are associated with increased patient risk and adverse outcome. Patient Blood Management (PBM) is the multidisciplinary, multimodal approach to optimising the care of patients who may require blood transfusion. Guidelines exist with many recommendations throughout the perioperative pathway. However, the efficacy of individual recommendations as an intervention in terms of clinical outcome can be confusing. In the UK the first national audit of PBM in surgery was carried out in 2015. This reviewed the use and impact of PBM recommendations in hospitals throughout the UK where major surgery was undertaken. The current evidence base for these PBM recommendations was reviewed and the patient outcome in terms of blood transfusion use and length of hospital stay assessed in those where PBM interventions were followed. For the patient who presents with preoperative anaemia, 'quick wins' were identified that reduced blood transfusion use and reduced length of stay in hospital; preoperative discontinuation of anticoagulation or antiplatelet therapy, and intraoperative use of tranexamic acid and cell salvage.

The Year in Vascular Anesthesia: Selected Highlights From 2018

This special article is the second in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia that is specifically dedicated to highlights in vascular anesthesiology published in 2018. This review begins with 2 updates in preoperative medicine in the vascular surgery population, including recent publications regarding the management of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers and antiplatelet medications in the perioperative period. The next section focuses on complications related to thoracic endovascular aortic surgery, particularly as technology advances allow for endovascular repair of more complex anatomy. The final section focuses on quality in vascular surgery and evaluates recent publications that examine the safety and feasibility of fast-track endovascular aortic surgery. Even though this is only a sampling of the literature published in 2018 relevant to the cardiovascular anesthesiologist, these themes represent some of the topics most clinically relevant to the perioperative period.