Determination of etiologic mechanisms of strokes secondary to coronary artery bypass graft surgery

Clinical and subclinical acute brain injury caused by invasive cardiovascular procedures

Over the past 50 years, the number and invasiveness of percutaneous cardiovascular procedures globally have increased substantially. However, cardiovascular interventions are inherently associated with a risk of acute brain injury, both periprocedurally and postprocedurally, which impairs medical outcomes and increases health-care costs. Current international clinical guidelines generally do not cover the area of acute brain injury related to cardiovascular invasive procedures. In this international Consensus Statement, we compile the available knowledge (including data on prevalence, pathophysiology, risk factors, clinical presentation and management) to formulate consensus recommendations on the prevention, diagnosis and treatment of acute brain injury caused by cardiovascular interventions. We also identify knowledge gaps and possible future directions in clinical research into acute brain injury related to cardiovascular interventions.

Concomitant Carotid and Coronary Artery Disease Management: A Review of the Literature

This review examines current evidence regarding management of patients with both coronary and carotid artery disease. It highlights the elevated stroke risk after surgery for this cohort and scrutinizes approaches to minimize this risk. Various revascularization methods are outlined, including carotid endarterectomy (CEA), carotid artery stenting (CAS), and staged versus simultaneous surgical approaches. The importance of judiciously screening coronary artery bypass grafting (CABG) candidates for carotid stenosis is emphasized, suggesting risk factor-based targeted screening is noninferior to indiscriminate screening. Efficacy comparisons are made between revascularization strategies such as staged versus synchronous CEA/CABG, CAS, and hybrid techniques. Controversies surrounding necessity and optimal timing of carotid revascularization in asymptomatic patients are addressed, indicating a need for rigorous randomized controlled trials to establish definitive treatment algorithms.

Stroke risk after transcatheter aortic valve replacement in patients with carotid stenosis: A systematic review and meta-analysis

BACKGROUND

Stroke is a feared complication of transcatheter aortic valve replacement (TAVR). Patients undergoing TAVR typically have multiple comorbidities, such as carotid artery stenosis (CAS). We conducted the present meta-analysis to determine the risk of stroke and mortality following TAVR in patients with CAS.

METHODS

We searched PubMed/Medline, Scopus, ScienceDirect, and Cochrane Clinical Trials databases for clinical studies that compared CAS ≥50% and CAS ≥70% versus non-CAS TAVR population. The endpoints included the 30-day incidence of stroke or transient ischemic attack (TIA) and 30-day all-cause of mortality.

RESULTS

We identified seven studies that included 12,418 patients in the CAS group and 102,316 in the control group. CAS ≥50% was not associated with an increased risk of 30-day stroke or TIA after TAVR [risk ratio (RR): 1.38; 95% confidence interval (95% CI): 0.95-2.02; p = 0.09]. However, patients with CAS ≥70% had an increased risk of stroke or TIA (RR: 1.43; 95% CI: 1.02-2.01; p = 0.04). No difference in 30-day all-cause mortality was observed between CAS ≥50% or CAS ≥70% and control groups (RR: 1.09; 95% CI: 0.79-1.52; p = 0.59 and RR: 1.11; 95% CI: 0.85-1.45; p = 0.43, respectively).

CONCLUSIONS

CAS ≥70% was associated with an increased risk of stroke or TIA following TAVR compared with patients without CAS.

Carotid Interventions in Patients Undergoing Coronary Artery Bypass Grafting: A Narrative Review

Simultaneous carotid artery stenosis (CS) and coronary artery disease (CAD) is a common condition among patients with several cardiovascular risk factors; however, its optimal management still remains under investigation, such as the assumption that carotid disease is causally related to perioperative stroke and that preventive carotid revascularization decrease the risk of this complication. Synchronous surgical approach to both conditions, performing carotid endarterectomy (CEA) before coronary artery bypass graft (CABG) during the same procedure, should still be considered in selective patients, in order to reduce the risk of perioperative stroke during coronary cardiac surgery. For the same purpose, staged approaches, such as CEA followed by CABG or CABG followed by CEA during the same hospitalization or a few weeks later have been described. Hybrid approach with carotid artery stenting (CAS) and CABG can also be an option in selected cases, offering a minimally invasive procedure to treat CS among patients whom CABG cannot be postponed. When carotid intervention is indicated in patients with concomitant CAD requiring CABG, a personalized and tailored approach is mandatory, especially in asymptomatic patients, in order to define the ideal surgical strategy. The aim of this paper is to summarize the current "state of the art" of the different approaches to carotid artery diseases in patients undergoing CABG.

Intraoperative Blood Pressure Management and Its Effects on Postoperative Delirium After Cardiac Surgery: A Single-Center Retrospective Cohort Study

OBJECTIVES

There is accumulating evidence that blood pressure management might be associated with end-organ dysfunction after cardiac surgery. This study aimed to investigate the impact of intraoperative hypotension (IOH) on adverse neurologic outcomes and mortality.

DESIGN

A single-center retrospective cohort study.

SETTING

The Heart and Diabetes Centre Bad Oeynhausen NRW, Ruhr-University Bochum.

PARTICIPANTS

This retrospective cohort study included 31,315 adult patients who underwent elective cardiac surgery at the authors' institution between January 2009 and December 2018.

INTERVENTIONS

All cardiac surgery procedures except assist device implantation, organ transplantation, and emergency surgery.

MEASUREMENTS AND MAIN RESULTS

Adverse neurologic outcomes were defined as postoperative delirium and stroke. IOH was defined as mean arterial pressure below 60 mmHg for >2 minutes. The frequency of IOH episodes and the cumulative IOH duration were recorded. The association between IOH and adverse neurologic outcomes was examined with unadjusted statistical analysis and multiple logistic regression analysis. Eight hundred forty-nine (2.9%) patients developed postoperative stroke, and 2,401 (7.7%) patients developed postoperative delirium. The frequency of IOH episodes was independently associated with postoperative delirium in the multiple logistic regression analysis (odds ratio 1.02, 95% CI 1.003-1.03, p < 0.001), whereas there was no association between it and stroke.

CONCLUSION

This large retrospective monocentric cohort study revealed that increased episodes of IOH were associated with the risk of developing postoperative delirium after cardiac surgery. This might have important clinical implications with respect to careful and precise hemodynamic monitoring and proactive treatment, especially in patients with increased risk for postoperative delirium.

Perioperative and Long-Term Outcomes in Patients Undergoing Synchronous Carotid Endarterectomy and Coronary Artery Bypass Grafting: A Single-Center Experience

INTRODUCTION

Patients requiring coronary artery bypass grafting (CABG) and carotid endarterectomy (CEA) can be managed with staged (CEA before CABG), reverse staged (CABG before CEA) or synchronous treatment. This single-center retrospective study evaluated the outcomes in patients undergoing planned synchronous CEA and CABG.

METHODS

Between 2000 and 2020 a total of 185 patients with symptomatic triple-vessel or left main coronary artery disease associated with 70-99% asymptomatic or 50-99% symptomatic uni- or bilateral internal carotid artery (ICA) stenosis underwent synchronous CEA and CABG at our institution. Study endpoints were defined as mortality, stroke and myocardial infarction at 30 days. Additionally, the composite endpoint of these events was investigated.

RESULTS

At 30 days, mortality, stroke and myocardial infarction rates were 5.9%, 8.1% (permanent [unresolved deficit at discharge] 5.4%) and 3.8%, respectively, and the composite endpoint was reached in 13.0% of patients. Patients suffering from a stroke more frequently had a contralateral 70-99% ICA stenosis (60.0% vs. 17.3%; p < 0.001), peripheral artery disease (73.3% vs. 38.9%; p = 0.013) and prolonged cardiopulmonary bypass time (mean 119 ± 62 min vs. 84 ± 29 min; p = 0.012). Multivariate logistic regression analysis revealed the duration of cardiopulmonary bypass (odds ratio [OR] 1.024; 95% confidence interval [CI] 1.002-1.046; p = 0.034), a history of type 2 diabetes mellitus (OR 5.097; 95% CI 1.161-22.367; p = 0.031) and peripheral artery disease (OR 5.814; 95% CI 1.231-27.457; p = 0.026) as independent risk factors for reaching the composite endpoint.

CONCLUSION

Patients undergoing synchronous CEA and CABG face an elevated risk of perioperative cardiovascular events, particularly an increased stroke risk in patients with symptomatic and bilateral ICA stenosis. Graphical Abstract available for this article.

Endovascular Treatment of Acute Ischemic Stroke After Cardiac Interventions in the United States

Importance

Ischemic stroke is a serious complication of cardiac intervention, including surgery and percutaneous procedures. Endovascular thrombectomy (EVT) is an effective treatment for ischemic stroke and may be particularly important for cardiac intervention patients who often cannot receive intravenous thrombolysis.

Objective

To examine trends in EVT for ischemic stroke during hospitalization of patients with cardiac interventions vs those without in the United States.

Design, Setting, and Participants

This cohort study involved a retrospective analysis using data for 4888 US hospitals from the 2016-2020 National Inpatient Sample database. Participants included adults (age ≥18 years) with ischemic stroke (per codes from the International Statistical Classification of Diseases, Tenth Revision, Clinical Modification), who were organized into study groups of hospitalized patients with cardiac interventions vs without. Individuals were excluded from the study if they had either procedure prior to admission, EVT prior to cardiac intervention, EVT more than 3 days after admission or cardiac intervention, or endocarditis. Data were analyzed from April 2023 to October 2023.

Exposures

Cardiac intervention during admission.

Main Outcomes and Measures

The odds of undergoing EVT by cardiac intervention status were calculated using multivariable logistic regression. Adjustments were made for stroke severity in the subgroup of patients who had a National Institutes of Health Stroke Scale (NIHSS) score documented. As a secondary outcome, the odds of discharge home by EVT status after cardiac intervention were modeled.

Results

Among 634 407 hospitalizations, the mean (SD) age of the patients was 69.8 (14.1) years, 318 363 patients (50.2%) were male, and 316 044 (49.8%) were female. A total of 12 093 had a cardiac intervention. An NIHSS score was reported in 218 576 admissions, 216 035 (34.7%) without cardiac intervention and 2541 (21.0%) with cardiac intervention (P < .001). EVT was performed in 23 660 patients (3.8%) without cardiac intervention vs 194 (1.6%) of those with cardiac intervention (P < .001). After adjustment for potential confounders, EVT was less likely to be performed in stroke patients with cardiac intervention vs those without (adjusted odds ratio [aOR], 0.27; 95% CI, 0.23-0.31), which remained consistent after adjusting for NIHSS score (aOR, 0.28; 95% CI, 0.22-0.35). Among individuals with a cardiac intervention, receiving EVT was associated with a 2-fold higher chance of discharge home (aOR, 2.21; 95% CI, 1.14-4.29).

Conclusions and Relevance

In this study, patients hospitalized with ischemic stroke and cardiac intervention may be less than half as likely to receive EVT as those without cardiac intervention. Given the known benefit of EVT, there is a need to better understand the reasons for lower rates of EVT in this patient population.

Left atrial appendage occlusion for patients with valvular diseases without atrial fibrillation (the OPINION Study): study protocol for a multicentre, randomised controlled trial

INTRODUCTION

Atrial fibrillation (AF) is a significant cause of perioperative stroke in aortic and mitral valve surgeries. Although several large studies have evaluated surgical left atrial appendage occlusion (SLAAO) during cardiac surgeries, their retrospective nature and an uncontrolled broad spectrum of conditions leave them subject to potential residual confounding. This trial aims to test the hypothesis that opportunistic SLAAO can prevent long-term stroke after cardiac surgery in patients receiving mitral or aortic valve surgeries without a history of AF and with a CHA2DS2-VASc score of 2 or higher.

METHODS AND DESIGN

This study is a single-blinded, multicentre, randomised controlled trial. A total of 2118 patients planning to undergo aortic or mitral surgery without AF will be recruited and equally randomised into intervention or control arms at a 1:1 ratio. In the intervention arm, suture excision of the left atrial appendage (LAA) will be performed during the operation in addition to the original surgery plan. In the control arm, the operation will be performed according to the surgery plan without any intervention on the LAA. The primary outcome is a composite of newly occurred ischaemic stroke or transient ischaemic attack and cardiovascular mortality during a 1-year follow-up. Secondary outcomes include postoperative AF, cardiovascular mortality, newly occurred ischaemic stroke, newly occurred transient ischaemic attack, newly occurred haemorrhagic stroke, bleeding events, and AF-associated health utilisation.

ETHICS AND DISSEMINATION

The Ethics Committee in Fuwai Hospital approved this study. Patients will give informed consent to the study. An information leaflet will be provided to participating patients to introduce the SLAAO procedure. Patients and the public will not get involved in developing the research hypothesis, study design or any other part of this protocol. We plan to publish several papers in peer-reviewed journals about the current research and these will include a description of the study's development and the main findings of the study.

TRIAL REGISTRATION NUMBER

ChiCTR2100042238.

Protease-Activated Receptors (PARs): Biology and Therapeutic Potential in Perioperative Stroke

Perioperative stroke is a devastating complication that occurs during surgery or within 30 days following the surgical procedure. Its prevalence ranges from 0.08 to 10% although it is most likely an underestimation, as sedatives and narcotics can substantially mask symptomatology and clinical presentation. Understanding the underlying pathophysiology and identifying potential therapeutic targets are of paramount importance. Protease-activated receptors (PARs), a unique family of G-protein-coupled receptors, are widely expressed throughout the human body and play essential roles in various physiological and pathological processes. This review elucidates the biology and significance of PARs, outlining their diverse functions in health and disease, and their intricate involvement in cerebrovascular (patho)physiology and neuroprotection. PARs exhibit a dual role in cerebral ischemia, which underscores their potential as therapeutic targets to mitigate the devastating effects of stroke in surgical patients.

Perioperative stroke

Ischaemic or haemorrhagic perioperative stroke (that is, stroke occurring during or within 30 days following surgery) can be a devastating complication following surgery. Incidence is reported in the 0.1-0.7% range in adults undergoing non-cardiac and non-neurological surgery, in the 1-5% range in patients undergoing cardiac surgery and in the 1-10% range following neurological surgery. However, higher rates have been reported when patients are actively assessed and in high-risk populations. Prognosis is significantly worse than stroke occurring in the community, with double the 30-day mortality, greater disability and diminished quality of life among survivors. Considering the annual volume of surgeries performed worldwide, perioperative stroke represents a substantial burden. Despite notable differences in aetiology, patient populations and clinical settings, existing clinical recommendations for perioperative stroke are extrapolated mainly from stroke in the community. Perioperative in-hospital stroke is unique with respect to the stroke occurring in other settings, and it is essential to apply evidence from other settings with caution and to identify existing knowledge gaps in order to effectively guide patient care and future research.

Intraoperative Blood Pressure Variability and Early Postoperative Stroke: A Case-Control Study

BACKGROUND

This study aims to assess the association of postoperative stroke with intraoperative hemodynamic variability and transfusion management.

METHODS

In this case-control study, adult patients (≥ 18 years) who had a stroke within 72 hours of a surgical procedure were matched to 2 control patients according to age, sex, and procedure type. Primary risk factors assessed were intraoperative fluid administration, blood product transfusion, vasopressor use, and measures of variability in systolic and diastolic blood pressure and heart rate: maximum, minimum, range, SD, and average real variability. The variables were analyzed with conditional logistic regression, which accounted for the 1:2 matched case-control study design.

RESULTS

Among 687 581 procedures, we identified 64 postoperative strokes (incidence, 9.3 [95% CI, 7.2-11.9] strokes per 100 000 procedures). These cases were matched with 128 controls. Stroke cases had higher Charlson cmorbidity index scores than did controls (P = .046). Blood pressure and heart rate variability measures were not associated with stroke. The risk of stroke was increased with red blood cell (RBC) transfusion (odds ratio [OR], 14.82; 95% CI, 3.40-64.66; P < .001), vasopressor use (OR, 3.91; 95% CI, 1.59-9.60; P = .003), and longer procedure duration (OR, 1.23/h; 95% CI, 1.01-1.51; P = .04). Multivariable analysis of procedure duration, RBC transfusion, and vasopressor use showed that only RBC transfusion was independently associated with an increased risk of stroke (OR, 10.10; 95% CI, 2.14-47.72; P = .004).

CONCLUSIONS

Blood pressure variability was not associated with an increased risk of postoperative stroke; however, RBC transfusion was an independent risk factor.

Endovascular carotid revascularization under open-chest extracorporeal circulation combined with cardiac surgery in unstable patients at increased risk of carotid-related stroke: SIMultaneous urgent cardiac surgery and MicroNet-covered stent carotid revascularization in extreme-risk patients-SIMGUARD Study

BACKGROUND

In patients at urgent need for cardiac surgery coexisting with increased-stroke-risk carotid stenosis, any staged intervention increases the risk of complications from the primarily unaddressed pathology. In this challenging cohort, we assessed safety and feasibility of endovascular carotid revascularization under open-chest extracorporeal circulation (ECC) combined with cardiac surgery (hybrid-room true simultaneous treatment).

METHODS

Per-protocol (PP), after general anesthesia induction, chest-opening and ECC stand-by installation, carotid stenting (CAS) was performed (femoral/radial or direct carotid access) with ad-hoc/on-hand switch to ECC cardiac surgery.

RESULTS

Over 78 months, 60 patients (70.7±6.9years, 85% male, all American Society of Anesthesiology grade IV) were enrolled. All were at increased carotid-related stroke risk (ipsilateral recent stroke/transient ischemick attack, asymptomatic cerebral infarct, increased-risk lesion morphology, bilateral severe stenosis). Majority of study procedures involved CAS+coronary bypass surgery or CAS+valve replacement±coronary bypass. 45 (75%) patients were PP- and 15 (25%) not-PP (NPP-) managed (context therapy). CAS was 100% neuroprotected (transient flow reversal-64.4%, filters-35.6%) and employed micronet-covered plaque-sequestrating stents with routine post-dilatation optimization/embedding. 4 deaths (6.7%) and 7 strokes (11.7%) occurred by 30-days. Despite CAS+surgery performed on aspirin and unfractionated heparin-only (delayed clopidogrel-loading), no thrombosis occurred in the stented arteries, and 30-days stent patency was 100%. NPP-management significantly increased the risk of death/ipsilateral stroke (OR 38.5; P<0.001) and death/any stroke (OR 12.3; P=0.002) by 30-days.

CONCLUSIONS

In cardiac unstable patients at increased carotid-related stroke risk who require urgent cardiac surgery, simultaneous cardiac surgery and CAS with micronet-covered stent lesion sequestration is feasible and safe and shows efficacy in minimizing stroke risk. Larger-scale, multicentric evaluation is warranted. (SIMGUARD NCT04973579).

Neurologic complications after cardiopulmonary bypass - A narrative review

Neurologic complications, associated with cardiac surgery and cardiopulmonary bypass (CPB) in adults, are common and can be devastating in some cases. This comprehensive review will not only consider the broad categories of stroke and neurocognitive dysfunction, but it also summarises other neurological complications associated with CPB, and it provides an update about risks, prevention and treatment. Where appropriate, we consider the impact of off-pump techniques upon our understanding of the contribution of CPB to adverse outcomes.

Meta-Analysis of the Prognostic Significance of Carotid Artery Stenosis in Patients Who Underwent Transcatheter Aortic Valve Implantation

Stroke is a known complication of both transcatheter aortic valve implantation (TAVI) and carotid artery stenosis (CAS). Whether CAS is a predictor of worse prognosis after TAVI is unclear. We performed a meta-analysis to assess the impact of CAS on the incidence of neurovascular complications and mortality after TAVI. We searched PubMed/MEDLINE and EMBASE databases from inception to January 2023. CAS was defined by ≥50% stenosis of at least 1 carotid artery. Studies comparing CAS versus non-CAS TAVI populations were included. Patients' baseline characteristics and 30-day clinical outcomes were extracted. End points included the 30-day incidence of neurovascular complications (stroke or transient ischemic attack) and 30-day all-cause mortality. We identified six studies, totaling 6,763 patients in the CAS group and 23,861 patients in the non-CAS group. Patients with CAS had a higher prevalence of hypertension, diabetes mellitus, dyslipidemia, previous myocardial infarction, coronary artery bypass graft, peripheral artery disease, previous neurovascular disease, and chronic kidney disease. There was no significant difference in the rates of 30-day neurovascular complications between CAS and non-CAS groups (relative risk 1.23, 95% confidence interval 0.63 to 2.40, p = 0.54). CAS was associated with a higher risk of 30-day all-cause mortality (relative risk 1.28, 95% confidence interval 1.12 to 1.47, p <0.001), not found in a sensitivity analysis. In conclusion, patients with CAS presented with a significantly higher co-morbidity burden. CAS was not associated with an increased risk of 30-day neurovascular complications. 30-day mortality was higher in the CAS group but that may be a surrogate of the heavy co-morbidity burden of patients with CAS.

Microvascular dysfunction following cardiopulmonary bypass plays a central role in postoperative organ dysfunction

Despite significant advances in surgical technique and strategies for tissue/organ protection, cardiac surgery involving cardiopulmonary bypass is a profound stressor on the human body and is associated with numerous intraoperative and postoperative collateral effects across different tissues and organ systems. Of note, cardiopulmonary bypass has been shown to induce significant alterations in microvascular reactivity. This involves altered myogenic tone, altered microvascular responsiveness to many endogenous vasoactive agonists, and generalized endothelial dysfunction across multiple vascular beds. This review begins with a survey of in vitro studies that examine the cellular mechanisms of microvascular dysfunction following cardiac surgery involving cardiopulmonary bypass, with a focus on endothelial activation, weakened barrier integrity, altered cell surface receptor expression, and changes in the balance between vasoconstrictive and vasodilatory mediators. Microvascular dysfunction in turn influences postoperative organ dysfunction in complex, poorly understood ways. Hence the second part of this review will highlight in vivo studies examining the effects of cardiac surgery on critical organ systems, notably the heart, brain, renal system, and skin/peripheral tissue vasculature. Clinical implications and possible areas for intervention will be discussed throughout the review.

Effective treatment of severe stenosis of the carotid and coronary arteries: a case study

It is considered acceptable to conservatively manage coronary artery bypass grafting patients with carotid artery disease without the need for preoperative corrective carotid revascularization. However, in the present case, rapidly progressive stroke symptoms with penumbra suggested in the arterial spin labeling, carotid artery stenting was performed successfully.

Risk and Subtypes of Stroke Following New-Onset Postoperative Atrial Fibrillation in Coronary Bypass Surgery: A Population-Based Cohort Study

Background New-onset postoperative atrial fibrillation (POAF) develops in approximately one-third of patients undergoing cardiac surgery and is associated with a higher incidence of ischemic stroke and increased mortality. However, it remains unknown to what extent ischemic stroke events in patients with POAF are cardioembolic and whether anticoagulant therapy is indicated. We investigated the long-term risk and pathogenesis of postoperative stroke in patients undergoing coronary artery bypass grafting experiencing POAF. Methods and Results This was a register-based cohort study. Data from the WDHR (Western Denmark Heart Registry) were linked with the DNPR (Danish National Patient Register), the Danish National Prescription Register, and the Cause of Death Register. All stroke diagnoses were verified, and ischemic stroke cases were subclassified according to pathogenesis. Furthermore, investigations of all-cause mortality and the use of anticoagulation medicine for the individual patient were performed. A total of 7813 patients without a preoperative history of atrial fibrillation underwent isolated coronary artery bypass grafting between January 1, 2010, and December 31, 2018, in Western Denmark. POAF was registered in 2049 (26.2%) patients, and a postoperative ischemic stroke was registered in 195 (2.5%) of the patients. After adjustment, there was no difference in the risk of ischemic stroke (hazard ratio [HR], 1.08 [95% CI, 0.74-1.56]) or all-cause mortality (HR, 1.09 [95% CI, 0.98-1.23]) between patients who developed POAF and non-POAF patients. Although not statistically significant, patients with POAF had a higher incidence rate (IR; per 1000 patient-years) of cardioembolic stroke (IR, 1 [95% CI, 0.6-1.6] versus IR, 0.5 [95% CI, 0.3-0.8]), whereas non-POAF patients had a higher incidence rate of large-artery occlusion stroke (IR, 1.1 [95% CI, 0.8-1.5] versus IR, 0.7 [95% CI, 0.4-1.4]). Early initiation of anticoagulation medicine was not associated with a lower risk of ischemic stroke. However, patients with POAF were more likely to die of cardiovascular causes than non-POAF patients (P<0.001). Conclusions We found no difference in the adjusted risk of postoperative stroke or all-cause mortality in POAF versus non-POAF patients. Patients with POAF after coronary artery bypass grafting presented with a higher, although not significant, proportion of ischemic strokes of the cardioembolic type.

Update on Minimalist TAVR Care Pathways: Approaches to Care in 2022

Purpose of Review

This review summarizes current data supporting a minimalist TAVR approach and identifies the need for additional study to optimize TAVR care. The authors discuss future directions of the TAVR landscape and how this necessitates evolution of minimalist care pathways.

Recent Findings

Transcatheter aortic valve replacement (TAVR) has become a mainstay in the treatment of aortic stenosis since the initial procedure in 2002. Recently, attention has shifted to TAVR optimization and the minimalist approach with a focus on minimizing procedural sedation, protocolization of perioperative management, and prioritization on early discharge. This approach has been shown to be safe and reduce procedure time, length of stay, and overall cost for hospital systems.

Summary

The minimalist care pathway avoids general anesthesia, shortens procedure time and length of stay, and reduces cost without changing mortality or readmission rates at 30 days. A variety of protocols have been proposed without a clear consensus on specific components or patient eligibility. There is a continued need for data regarding patient risk stratification, valve selection, and discharge strategy as TAVR becomes increasingly common.

Renal and Cerebral Hypoxia and Inflammation During Cardiopulmonary Bypass

Cardiac surgery-associated acute kidney injury and brain injury remain common despite ongoing efforts to improve both the equipment and procedures deployed during cardiopulmonary bypass (CPB). The pathophysiology of injury of the kidney and brain during CPB is not completely understood. Nevertheless, renal (particularly in the medulla) and cerebral hypoxia and inflammation likely play critical roles. Multiple practical factors, including depth and mode of anesthesia, hemodilution, pump flow, and arterial pressure can influence oxygenation of the brain and kidney during CPB. Critically, these factors may have differential effects on these two vital organs. Systemic inflammatory pathways are activated during CPB through activation of the complement system, coagulation pathways, leukocytes, and the release of inflammatory cytokines. Local inflammation in the brain and kidney may be aggravated by ischemia (and thus hypoxia) and reperfusion (and thus oxidative stress) and activation of resident and infiltrating inflammatory cells. Various strategies, including manipulating perfusion conditions and administration of pharmacotherapies, could potentially be deployed to avoid or attenuate hypoxia and inflammation during CPB. Regarding manipulating perfusion conditions, based on experimental and clinical data, increasing standard pump flow and arterial pressure during CPB appears to offer the best hope to avoid hypoxia and injury, at least in the kidney. Pharmacological approaches, including use of anti-inflammatory agents such as dexmedetomidine and erythropoietin, have shown promise in preclinical models but have not been adequately tested in human trials. However, evidence for beneficial effects of corticosteroids on renal and neurological outcomes is lacking. © 2021 American Physiological Society. Compr Physiol 11:1-36, 2021.

Neurological Complications of Cardiac Procedures

Neurological complications after cardiac surgery and percutaneous cardiac interventions are not uncommon. These include periprocedural stroke, postoperative cognitive dysfunction after cardiac surgery, contrast-induced encephalopathy after percutaneous interventions, and seizures. In this article, we review the incidence, pathophysiology, diagnosis, and management of these complications. Improved understanding of these complications could lead to their prevention, faster detection, and facilitation of diagnostic workup and appropriate treatment.

Predictive Factors of Perioperative Stroke-Related Mortality Following Vascular Surgery: A Retrospective Analysis

OBJECTIVE

Vascular surgical procedures have one of the highest risks of perioperative stroke and stroke-related mortality, yet the independent risk factors contributing to this increased mortality have not been described. Perioperative strokes are thought to result from a combination of embolism and hypoperfusion mechanisms. The purpose of this study is to describe the independent predictors of perioperative stroke-related mortality in the vascular surgical population using the Pennsylvania Health Care Cost Containment Council (PHC4) database which collects cause of death data.

METHODS

This retrospective, case-control study evaluated 4,128 patients aged 18-99 who underwent a vascular, non-carotid surgical procedure and subsequently suffered perioperative mortality. Common surgical comorbidities and risk factors for perioperative stroke, including carotid stenosis and atrial fibrillation, were evaluated in multivariate regression analysis.

RESULTS

Patients with carotid stenosis were 2.6 (aOR, 95% CI 1.4-4.5) times more likely to suffer perioperative mortality from stroke than from other causes. Additionally, in-hospital stroke, history of stroke, admission from a healthcare facility, and cancer were all positive predictive factors, whereas atrial fibrillation, emergency admission, hypertension, and diabetes were associated with decreased risk of perioperative stroke-related mortality.

CONCLUSIONS

Identification of vascular surgical population-specific predictors of stroke-related mortality can help to enhance preoperative risk-stratification tools and guide perioperative management of identified high-risk patients. Increased neurophysiologic monitoring in the perioperative period to prevent delays in diagnosis of perioperative stroke offers a strategy to reduce risk of perioperative stroke-related mortality in vascular surgical patients.

A Comprehensive Review of Risk Factor, Mechanism, and Management of Left Ventricular Assist Device-Associated Stroke

The use of left ventricular assist devices (LVADs) has been increasing in the last decade, along with the number of patients with advanced heart failure refractory to medical therapy. Ischemic stroke and intracranial hemorrhage remain the leading causes of morbidity and mortality in LVAD patients. Despite the common occurrence and the significant outcome impact, underlying mechanisms and management strategies of stroke in LVAD patients are controversial. In this article, we review our current knowledge on pathophysiology and risk factors of LVAD-associated stroke, outline the diagnostic approach, and discuss treatment strategies.

Perioperative Neurological Evaluation and Management to Lower the Risk of Acute Stroke in Patients Undergoing Noncardiac, Nonneurological Surgery: A Scientific Statement From the American Heart Association/American Stroke Association

Perioperative stroke is a potentially devastating complication in patients undergoing noncardiac, nonneurological surgery. This scientific statement summarizes established risk factors for perioperative stroke, preoperative and intraoperative strategies to mitigate the risk of stroke, suggestions for postoperative assessments, and treatment approaches for minimizing permanent neurological dysfunction in patients who experience a perioperative stroke. The first section focuses on preoperative optimization, including the role of preoperative carotid revascularization in patients with high-grade carotid stenosis and delaying surgery in patients with recent strokes. The second section reviews intraoperative strategies to reduce the risk of stroke, focusing on blood pressure control, perioperative goal-directed therapy, blood transfusion, and anesthetic technique. Finally, this statement presents strategies for the evaluation and treatment of patients with suspected postoperative strokes and, in particular, highlights the value of rapid recognition of strokes and the early use of intravenous thrombolysis and mechanical embolectomy in appropriate patients.

Temporal Trends, Predictors, and Outcomes of Acute Ischemic Stroke in Acute Myocardial Infarction in the United States

Background

There are limited contemporary data prevalence and outcomes of acute ischemic stroke (AIS) complicating acute myocardial infarction (AMI).

Methods and Results

Adult (>18 years) AMI admissions using the National Inpatient Sample database (2000–2017) were evaluated for in‐hospital AIS. Outcomes of interest included in‐hospital mortality, hospitalization costs, length of stay, discharge disposition, and use of tracheostomy and percutaneous endoscopic gastrostomy. The discharge destination was used to classify survivors into good and poor outcomes. Of a total 11 622 528 AMI admissions, 183 896 (1.6%) had concomitant AIS. As compared with 2000, in 2017, AIS rates increased slightly among ST‐segment–elevation AMI (adjusted odds ratio, 1.10 [95% CI, 1.04–1.15]) and decreased in non–ST‐segment–elevation AMI (adjusted odds ratio, 0.47 [95% CI, 0.46–0.49]) admissions (P<0.001). Compared with those without, the AIS cohort was on average older, female, of non‐White race, with greater comorbidities, and higher rates of arrhythmias. The AMI‐AIS admissions received less frequent coronary angiography (46.9% versus 63.8%) and percutaneous coronary intervention (22.7% versus 41.8%) (P<0.001). The AIS cohort had higher in‐hospital mortality (16.4% versus 6.0%; adjusted odds ratio, 1.75 [95% CI, 1.72–1.78]; P<0.001), longer hospital length of stay, higher hospitalization costs, greater use of tracheostomy and percutaneous endoscopic gastrostomy, and less frequent discharges to home (all P<0.001). Among AMI‐AIS survivors (N=153 318), 57.3% had a poor functional outcome at discharge with relatively stable temporal trends.

Conclusions

AIS is associated with significantly higher in‐hospital mortality and poor functional outcomes in AMI admissions.

Disease Mechanisms of Perioperative Organ Injury

Despite substantial advances in anesthesia safety within the past decades, perioperative mortality remains a prevalent problem and can be considered among the top causes of death worldwide. Acute organ failure is a major risk factor of morbidity and mortality in surgical patients and develops primarily as a consequence of a dysregulated inflammatory response and insufficient tissue perfusion. Neurological dysfunction, myocardial ischemia, acute kidney injury, respiratory failure, intestinal dysfunction, and hepatic impairment are among the most serious complications impacting patient outcome and recovery. Pre-, intra-, and postoperative arrangements, such as enhanced recovery after surgery programs, can contribute to lowering the occurrence of organ dysfunction, and mortality rates have improved with the advent of specialized intensive care units and advances in procedures relating to extracorporeal organ support. However, no specific pharmacological therapies have proven effective in the prevention or reversal of perioperative organ injury. Therefore, understanding the underlying mechanisms of organ dysfunction is essential to identify novel treatment strategies to improve perioperative care and outcomes for surgical patients. This review focuses on recent knowledge of pathophysiological and molecular pathways leading to perioperative organ injury. Additionally, we highlight potential therapeutic targets relevant to the network of events that occur in clinical settings with organ failure.

Considerations for Reduction of Risk of Perioperative Stroke in Adult Patients Undergoing Cardiac and Thoracic Aortic Operations: A Scientific Statement From the American Heart Association

Perioperative stroke is one of the most severe and feared complications of cardiac surgery. Based on the timing of onset and detection, perioperative stroke can be classified as intraoperative or postoperative. The pathogenesis of perioperative stroke is multifactorial, which makes prediction and prevention challenging. However, information on its incidence, mechanisms, diagnosis, and treatment can be helpful in minimizing the perioperative neurological risk for individual patients. We herein provide suggestions on preoperative, intraoperative, and postoperative strategies aimed at reducing the risk of perioperative stroke and at improving the outcomes of patients who experience a perioperative stroke.

[Perioperative stroke]

Perioperative stroke is defined as an ischemic cerebrovascular event that occurs during or within 30 days after surgery and is associated with an increased perioperative risk of morbidity and mortality. Depending on the type of surgery stroke is diagnosed in up to 11% of all patients in the perioperative period. Patients with a history of ischemic stroke or transitory ischemic attack have an increased risk for perioperative stroke. Therefore, a critical assessment of indications and the timing of surgery are crucial to prevent recurring stroke in this patient population. Importantly, individualized blood pressure management is essential for optimization of cerebral perfusion during the perioperative period.This article provides a summary of the epidemiology, risk factors, and etiology of perioperative stroke. Moreover, possible preventive strategies relevant for the anesthesiologist are reviewed.

Investigation of the Relationship between Cerebral Near-Infrared Spectroscopy Measurements and Cerebrovascular Event in Coronary Artery Bypass Grafting Operation in Patients without Carotid Stenosis and Patients with Carotid Stenosis below Surgical Margins

OBJECTIVES

Stroke is an important cause of mortality and morbidity in surgery. In the present study, we examined the cerebral oximetry values of patients with carotid artery stenosis who did not present surgical indications and those who did not present carotid artery stenosis in coronary artery bypass grafting (CABG) surgery by comparing their cerebral oximetry values with cerebrovascular disease (CVD).

METHODS

Between January and May 2014, 40 patients who underwent isolated CABG were included in the study. Cerebral oximetry probes were placed prior to induction of anesthesia. Cerebral oximetry values were recorded before induction, in the pump (cardiopulmonary bypass) inlet period, in the post-clamp period, in the pump outlet period, and in the intensive care unit and neurological complications.

RESULTS

There was no difference between the groups in terms of demographic data and routine follow-up parameters. Intraoperative surgical data and early postoperative results were similar in both groups. When comparing the groups, there were no statistically significant results in cerebral oximetry values and CVD development. Only one patient in group 2 had postoperative CVD and this patient was discharged from the hospital with right hemiplegia. Mean arterial pressure (MAP)levels were significantly higher in Group 2 (P<0.05).

CONCLUSION

The follow-up of cerebral perfusion with a method like near-infrared spectroscopy (NIRS) will ensure that MAP is adjusted with interventions that will be made according to changes in NIRS. Thus, it will be possible to avoid unnecessary medication and flow-rate increase with cerebral oxygen saturation (rSO2) follow-up.

Management of Antithrombotic Agents During Surgery or Other Kinds of Medical Procedures With Bleeding: The MARK Study

Background Optimal management of antithrombotic agents during surgery has yet to be established. We performed a prospective multicenter observational study to determine the current status of the management of antithrombotic agents during surgery or other medical procedures with bleeding (MARK [Management of Antithrombotic Agents During Surgery or Other Kinds of Medical Procedures With Bleeding] study) in Japan. Methods and Results The participants were 9700 patients who received oral antithrombotic agents and underwent scheduled medical procedures with bleeding at 59 National Hospital Organization institutions in Japan. Primary outcomes were thromboembolic events, bleeding events, and death within 2 weeks before and 4 weeks after the procedures. We investigated the relationships between each outcome and patient demographics, comorbidities, type of procedure, and management of antithrombotic therapy. With respect to the periprocedural management of antithrombotic agents, 3551 patients continued oral antithrombotic agents (36.6%, continuation group) and 6149 patients discontinued them (63.4%, discontinuation group). The incidence of any thromboembolic event (1.7% versus 0.6%, P<0.001), major bleeding (7.6% versus 0.4%, P<0.001), and death (0.8% versus 0.4%, P<0.001) was all greater in the discontinuation group than the continuation group. In multivariate analysis, even after adjusting for confounding factors, discontinuation of anticoagulant agents was significantly associated with higher risk for both thromboembolic events (odds ratio: 4.55; 95% CI, 1.67-12.4; P=0.003) and major bleeding (odds ratio: 11.1; 95% CI, 2.03-60.3; P=0.006) in procedures with low bleeding risk. In contrast, heparin bridging therapy was significantly associated with higher risk for both thromboembolic events (odds ratio: 2.03; 95% CI, 1.28-3.22; P=0.003) and major bleeding (odds ratio: 1.36; 95% CI, 1.10-1.68; P=0.005) in procedures with high bleeding risk. Conclusions Discontinuation of oral antithrombotic agents and addition of low-dose heparin bridging therapy appear to be significantly associated with adverse events in the periprocedural period.

Compared with matched controls, patients with postoperative atrial fibrillation (POAF) have increased long-term AF after CABG, and POAF is further associated with increased ischemic stroke, heart failure and mortality even after adjustment for AF

Objective

To analyze (1) associations between postoperative atrial fibrillation (POAF) after CABG and long-term cardiovascular outcome, (2) whether associations were influenced by AF during follow-up, and (3) if morbidities associated with POAF contribute to mortality.

Methods

An observational cohort study of 7145 in-hospital survivors after isolated CABG (1996–2012), with preoperative sinus rhythm and without AF history. Incidence of AF was compared with matched controls. Time-updated covariates were used to adjust for POAF-related morbidities during follow-up, including AF.

Results

Thirty-one percent of patients developed POAF. Median follow-up was 9.8 years. POAF patients had increased AF compared with matched controls (HR 3.03; 95% CI 2.66–3.49), while AF occurrence in non-POAF patients was similar to controls (1.00; 0.89–1.13). The observed AF increase among POAF patients compared with controls persisted over time (> 10 years 2.73; 2.13–3.51). Conversely, the non-POAF cohort showed no AF increase beyond the first postoperative year. Further, POAF was associated with long-term AF (adjusted HR 3.20; 95% CI 2.73–3.76), ischemic stroke (1.23; 1.06–1.42), heart failure (1.44; 1.27–1.63), overall mortality (1.21; 1.11–1.32), cardiac mortality (1.35; 1.18–1.54), and cerebrovascular mortality (1.54; 1.17–2.02). These associations remained after adjustment for AF during follow-up. Adjustment for other POAF-associated morbidities weakened the association between POAF and overall mortality, which became non-significant.

Conclusions

Patients with POAF after CABG had three times the incidence of long-term AF compared with both non-POAF patients and matched controls. POAF was associated with long-term ischemic stroke, heart failure, and corresponding mortality even after adjustment for AF during follow-up. The increased overall mortality was partly explained by morbidities associated with POAF.

Graphic abstract

Electronic supplementary material

The online version of this article (10.1007/s00392-020-01614-z) contains supplementary material, which is available to authorized users.

An analysis of the risk of perioperative ischemic stroke in patients undergoing non-cardiovascular and non-neurological surgeries

Objectives: This study aimed to assess the preoperative risk factor for perioperative ischemic stroke (PIS) in patients undergoing non-cardiovascular and non-neurological surgeries.Methods: Patients were retrospectively enrolled and grouped into two groups at a ratio of 1:2 according to their PIS status, i.e. patients with PIS in disease group, and patients without PIS in control group. Univariate analysis and multivariate logistic regression analysis were performed on admission laboratory test indices and preoperative risk factors for stroke. The pooled cohort equation (PCE), Essen Stroke Risk Score (ESRS), and Stroke Prognostic Instrument II (SPI-II) were used to separately assess the risk of stroke in patients with or without a history of stroke.Results: There were significant differences between the two groups in the levels of high-density lipoprotein cholesterol (HDL-C), prealbumin, renal insufficiency, dyslipidemia, coronary heart disease, anemia, and hemoglobin; the incidence of electrolyte disturbance; and previous histories of smoking, drinking, and stroke. Multivariate logistic regression analysis showed that renal insufficiency, histories of smoking and stroke, and decreased HDL-C can increase the risk of PIS. There were no significant differences between the disease group and the control group in ESRS or SPI-II score in patients with stroke history. There was a significant difference between the two groups in the risk of PIS evaluated by PCE in patients without stroke history.Conclusions: History of stroke and smoking, renal insufficiency, and low HDL-C are independent risk factors for PIS. It is feasible to assess the risk of stroke in preoperative patients using PCE in clinical practice.

Numerical Investigation of Blood Flow Characteristics through Cannulated Aorta

Cannulation of the aorta is done in order to provide oxygenation and circulatory function through the use of the heart lung machine during cardio-pulmonary bypass (CPB). The nature of the blood flow through the aorta and its ramifications during CPB is mostly linear as compared to the physiological flow, which is pulsatile in nature. This leads to the development of multiple morbidities caused by the development of emboli and atheromas. Perioperative postoperative care is necessitated by these conditions. As such the understanding of the blood flow characteristics is necessitated in order to effectively prevent the formation of emboli and to prevent the "Sandblasting" effect. The authors in this work seek to investigate the nature of blood flow through the aorta under such circumstances. The results obtained show the nature of blood flow in the cannulated aorta as well as the optimum angle of placement of the cannula with respect to the aortic wall.

One-day, sequential carotid artery stenting followed by cardiac surgery in patients with severe carotid and cardiac disease

Optimal management of patients with internal carotid artery (ICA) stenosis concurrent with severe cardiac disease remains undefined. The aim of this study is to evaluate the safety and feasibility of the one-day, sequential approach by carotid artery stenting (CAS) immediately followed by cardiac surgery. The study included 70 consecutive patients with symptomatic > 50% or ⩾ 80% asymptomatic ICA stenosis coexisting with severe coronary/valve disease, who underwent one-day, sequential CAS + cardiac surgery. The majority of patients (85.7%) had CSS class III or IV angina and 10% had non-ST elevation myocardial infarction. The EuroSCORE II risk was 2.4% (IQR 1.69-3.19%). All CAS procedures were performed according to the 'tailored' algorithm with a substantial use of proximal neuroprotection devices of 44.3%. Closed-cell (75.7%) and mesh-covered (18.6%) stents were implanted in most cases. The majority of patients underwent isolated coronary artery bypass grafting (88.6%) or isolated valve replacement (7.1%). No major adverse cardiac and cerebrovascular events (MACCE) occurred at the CAS stage. There were three (4.3%) perioperative MACCE: one myocardial infarction and two deaths. All MACCE were related to cardiac surgery and were due to the high surgical risk profile of the patients. Up to 30 days, no further MACCE were observed. No perioperative or 30-day neurological complications occurred. In this patient series, one-day, sequential CAS and cardiac surgery was relatively safe and did not result in neurological complications. Thus, a strategy of preoperative CAS could be considered for patients with severe or symptomatic ICA stenosis who require urgent cardiac surgery.

[Immediate and intermediate results of staged carotid endarterectomy in combination with coronary artery bypass grafting]

The purpose of our investigation was to evaluate the immediate and intermediate results of staged operations of carotid endarterectomy and coronary artery bypass grafting in patients with multifocal atherosclerosis. We analysed a total of 475 operations. Of these, 371 (78.1%) patients underwent staged interventions (stage 1 - carotid endarterectomy, stage 2 - coronary artery bypass grafting). No neurological complications were observed after stage 1. Five (1.3%) patients developed cardiac arrhythmia in the form of atrial fibrillation, 7 (1.9%) were found to have transient neuropathy of cranial nerves. There were no lethal outcomes. Stage 2 was carried out 16±13 days after carotid endarterectomy. Of complications encountered, mention should be made of perioperative myocardial infarction in 1 (0.3%) patient, with 2 (0.6%) patients requiring emergency coronary bypass angiography. Newly onset atrial fibrillation was registered in 71 (19.1%) patients, haemorrhage followed by resternotomy in 6 (1.6%), and purulent wound complications in 4 (1.1%) patients. Death occurred in 1 (0.3%) patient. We also analysed the mid-term postoperative results (up to 32 months). The coverage amounted to 151 patients. The incidence rate of major adverse cardiac and cerebrovascular events (MACCE) was 6% (myocardial infarction - 2, acute cerebral ischaemia - 1, repeat myocardial revascularization - 5, lethal outcome - 1). Based on the obtained findings it may be concluded that staged operations on the carotid basin and coronary arteries by the number of complications are comparable to those after isolated coronary artery bypass grafting.

High variance of intraoperative blood pressure predicts early cerebral infarction after revascularization surgery in patients with Moyamoya disease

Few studies focused on the intraoperative blood pressure in Moyamoya disease (MMD) patients. We aimed to clarify whether or not it relates to early cerebral infarction after revascularization. We reviewed a retrospective cohort of Moyamoya disease from 2011 to 2018 in Beijing Tiantan Hospital, and patients with radiologically confirmed early postoperative infarction were included in the analysis. Controls were matched based on age, sex, and revascularization modality at a ratio of 1:5. Perioperative clinical factors and intraoperative blood pressure data were collected and analyzed. A total of 52 patients out of 1497 revascularization surgeries (3.5%) who experienced CT or MRI confirmed early postoperatively cerebral infarction, aged 38.46 ± 11.70; 26 were male (50.0%). Average real variability (ARV)-systolic blood pressure (SBP) (OR 3.29, p = 0.003), ARV-diastolic blood pressure (DBP) (OR 4.10, p = 0.005), ARV-mean arterial pressure (MAP) (OR 4.08, p = 0.004), and the maximum drops of DBP (OR 1.08, p = 0.003) and MAP (OR 1.06, p = 0.004) were associated with early postoperative infarction. In patients who experienced massive cerebral infarction, the maximum drops of DBP (OR 1.11, p = 0.004) and MAP (OR 1.11, p = 0.003) are independent risk factors, whereas ARVs of SBP (OR 3.90, p < 0.001), DBP (OR 4.69, p = 0.008), and MAP (OR 4.72, p = 0.003) are significantly associated with regional infarction. High variance of intraoperative blood pressure and drastic blood pressure decline are independent risk factors for postoperative infarction in MMD patients who underwent revascularization surgery. Maintaining stable intraoperative blood pressure is suggested to prevent early postoperative cerebral infarction in MMD patients.

A functional evaluation of cerebral perfusion for coronary artery bypass grafting patients

We evaluate the utility of providing a pulsatile blood flow by applying off-pump coronary artery bypass grafting (CABG) or intra-aortic balloon pumping (IABP) with conventional CABG to prevent perioperative stroke in patients with cerebral hypoperfusion on single-photon emission-computed tomography (SPECT). A total of 286 patients underwent isolated CABG with a cerebral magnetic resonance angiography (MRA) evaluation between 2006 and 2015. Seventy-five had significant stenosis and/or occlusion of craniocervical vessels; the other 211 had no significant stenosis. Cerebral SPECT was performed for 49 (SPECT group) of the 75 patients. The SPECT group was further divided into a normal perfusion (NP) (n = 37); and a hypoperfusion (HP) (n = 12). In the present study we compared the NP group and the 211 patients with no significant stenosis (as a control group) to the HP group. No strokes occurred in the HP group, and 1 stroke occurred at the time of operation in the control group. Postoperative stroke within 30 days occurred in 3 patients in the control group; the difference was not statistically significant. The long-term stroke-free rates of the HP and Control group did not differ to a statistically significant extent. The functional evaluation of cerebral perfusion by SPECT is important when patients have significant stenotic lesions on cerebral MRA. Maintaining an adequate pulsatile flow by off-pump CABG or IABP with conventional CABG will help prevent perioperative stroke, even if cerebral hypoperfusion is detected by SPECT.

Risk of ischemic stroke after discharge from inpatient surgery: Does the type of surgery matter?

OBJECTIVE

Stroke is a well-known and devastating complication during the perioperative period. However, detailed stroke risk profiles within 90 days in patients discharged without stroke after inpatient surgery are not fully understood. Using the case-crossover design, we aimed to evaluate the risk of ischemic stroke in these patients.

METHODS

We included adult patients with the first hospitalization for ischemic stroke between 2011 and 2012 from 23 million enrollees in the National Health Insurance Research Database. Admission date of the hospitalization was defined as the case day and exactly 365 days before the admission date as the control day. The exposure was the last hospitalization for surgery within 1-30, 31-60, or 61-90 days (case period) before the case day or similar time intervals (control period) before the control day. Surgical types were grouped based on the International Classification of Diseases procedure codes. We performed conditional logistic regression adjusting for time-varying variables to determine the relationship between surgery and subsequent stroke, and case-time-control analyses to examine whether the results were confounded by the time-trend in surgery.

RESULTS

A total of 56596 adult patients (41% female, mean age 69 years) comprised the study population. After adjustment was made for confounding variables, an association between stroke and prior inpatient surgery within 30 days was observed (adjusted odds ratio 1.44; 95% confidence interval 1.29-1.61). Cardiothoracic, vascular, digestive surgery, and musculoskeletal surgery within 30 days independently predicted ischemic stroke in the case-crossover analysis. In the case-time-control analysis, inpatient surgery remained an independent risk factor for ischemic stroke, whereas only cardiothoracic, vascular, and digestive surgery independently predicted ischemic stroke.

CONCLUSIONS

Surgery as a whole independently increased the risk of ischemic stroke within 30 days. Among various types of surgery, cardiothoracic, vascular, and digestive surgery significantly increased the risk of ischemic stroke.

Postoperative thrombocytopenia: why you should consider antiplatelet therapy?

PURPOSE OF REVIEW

This review addresses the role of platelets in perioperative ischemic complications involving the brain, kidneys, and gastrointestinal tract, and long-term survival in patients undergoing coronary artery bypass grafting surgery. Importantly, findings of several recent clinical studies will be discussed with emphasis on platelet activation and leukocyte inflammatory responses as important mediators of vascular microthrombosis and ischemic injury.

RECENT FINDINGS

Our recent findings suggest that in some patients, the hemostatic balance during and after surgery may shift toward a hypercoagulable state and contribute to acute organ failure.

SUMMARY

For over 6 decades, major postoperative complications after cardiac surgery have remained unchanged. The potential influence of microthrombosis involving platelets has been underappreciated and use of perioperative antiplatelet therapy remains very limited - primarily because of a culture of fear of bleeding.