Stroke in cardiac surgical patients: determinants and outcome

Stroke after heart valve surgery: a single center institution report

INTRODUCTION

Stroke is a potentially debilitating complication of heart valve replacement surgery, with rates ranging from 1 to 10%. Despite advancements in surgical techniques, the incidence of postoperative stroke remains a significant concern, impacting patient outcomes and healthcare resources. This study aims to investigate the incidence, risk factors, and outcomes of in-hospital adverse neurologic events, particularly stroke, following valve replacement. The analysis focuses on identifying patient characteristics and procedural factors associated with increased stroke risk.

METHODS

This retrospective study involves a review of 417 consecutive patients who underwent SVR between January 2004 and December 2022. The study cohort was extracted from a prospectively recorded cardiac intensive care unit database. Preoperative and perioperative data were collected, and subjects with specific exclusion criteria were omitted from the analysis. The analysis includes demographic information, preoperative risk factors, and perioperative variables.

RESULTS

The study identified a 4.3% incidence of postoperative stroke among SVR patients. Risk factors associated with increased stroke susceptibility included prolonged cardiopulmonary bypass time, aortic cross-clamp duration exceeding 90 min, prior stroke history, diabetes mellitus, and mitral valve annulus calcification. Patients undergoing combined procedures, such as aortic valve replacement with mitral valve replacement or coronary artery bypass grafting with AVR and MVR, (OR = 10.74, CI:2.65-43.44, p-value = < 0.001) and (OR = 11.66, CI:1.02-132.70, p-value = 0.048) respectively, exhibited elevated risks. Internal carotid artery stenosis (< 75%) and requiring prolonged inotropic support were also associated with increased stroke risk(OR = 3.04, CI:1.13-8.12, P-value = 0.026). The occurrence of stroke correlated with extended intensive care unit stay (OR = 1.12, CI: 1.04-1.20, P-value = 0.002) and heightened in-hospital mortality.

CONCLUSION

In conclusion, our study identifies key risk factors and underscores the importance of proactive measures to reduce postoperative stroke incidence in surgical valve replacement patients.

Early Postoperative Neurologic Events Are Associated With Worse Outcome and Fatal Midterm Survival After Adult Heart Transplantation

Background Neurologic events during primary stay in heart transplant (HTx) recipients may be associated with reduced outcome and survival, which we aim to explore with the current study. Methods and Results We screened and included all patients undergoing HTx in our center between September 2010 and December 2022 (n=268) and checked for the occurrence of neurologic events within their index stay. Neurologic events were defined as ischemic stroke, hemorrhage, hypoxic ischemic injury, or acute symptomatic neurologic dysfunction without central nervous system injury. The cohort was then divided into recipients with (n=33) and without (n=235) neurologic events after HTx. Using a multivariable Cox regression model, the association of neurologic events after HTx and survival was assessed. Recipients with neurologic events displayed a longer intensive care unit stay (30 versus 16 days; P=0.009), longer mechanical ventilation (192 versus 48 hours; P<0.001), and higher need for blood transfusion, and need for hemodialysis after HTx was substantially higher (81% versus 55%; P=0.01). Resternotomy (36% versus 26%; P=0.05) and mechanical life support (extracorporeal life support) after HTx (46% versus 24%; P=0.02) were also significantly higher in patients with neurologic events. Covariable-adjusted multivariable Cox regression analysis revealed a significant independent association of neurologic events and increased 30-day (hazard ratio [HR], 2.5 [95% CI, 1.0-6.0]; P=0.049), 1-year (HR, 2.2 [95% CI, 1.1-4.3]; P=0.019), and overall (HR, 2.5 [95% CI, 1.5-4.2]; P<0.001) mortality after HTx and reduced Kaplan-Meier survival up to 5 years after HTx (P<0.001). Conclusions Neurologic events after HTx were strongly and independently associated with worse postoperative outcome and reduced survival up to 5 years after HTx.

Predictors and Outcomes of Stroke After Isolated Coronary Artery Bypass Grafting. A Single-Center Experience in 20,582 Patients

OBJECTIVE

Stroke remains a devastating complication after cardiac surgical procedures despite perioperative monitoring and management advances. This study aimed to determine the predictors of stroke in a large, contemporary coronary artery surgery population.

DESIGN

Patient data were analyzed retrospectively.

SETTING

This single-center study was performed in the Catharina Hospital (Eindhoven).

PARTICIPANTS

All patients who underwent isolated coronary artery bypass grafting (CABG) between January 1998 and February 2019 were included.

INTERVENTIONS

Isolated CABG.

MEASUREMENTS AND MAIN RESULTS

The primary endpoint was a postoperative stroke, defined according to the international updated definition for stroke. Logistic regression was performed to retrieve variables associated with postoperative stroke. A total of 20,582 patients underwent CABG during the period of the study. Stroke was observed in 142 patients (0.7%), of which 75 (52.8%) occurred during the first 72 hours. The incidence of postoperative stroke declined over the years. A significantly higher 30-day mortality rate was seen in patients with stroke (20.4%) compared with 1.8% in the rest of the population; p < 0.001. Multivariate logistic regression analysis showed age, peripheral arterial disease, reexploration for bleeding, perioperative myocardial infarction, and year of surgery as independent predictors for stroke. Patients with postoperative stroke had worse long-term survival (log-rank p < 0.001). Cox regression analysis revealed postoperative stroke (odds ratio 2.13 [1.73-2.64)) as an independent predictor of late mortality.

CONCLUSIONS

Stroke after CABG is associated with high early and late mortality. Age, peripheral vascular disease, and the year of surgery were associated with postoperative stroke.

Bayesian networks identify determinants of outcomes following cardiac surgery in a UK population

BACKGROUND

Traditional risk stratification tools do not describe the complex principle determinant relationships that exist amongst pre-operative and peri-operative factors and their influence on cardiac surgical outcomes. This paper reports on the use of Bayesian networks to investigate such outcomes.

METHODS

Data were prospectively collected from 4776 adult patients undergoing cardiac surgery at a single UK institute between April 2012 and May 2019. Machine learning techniques were used to construct Bayesian networks for four key short-term outcomes including death, stroke and renal failure.

RESULTS

Duration of operation was the most important determinant of death irrespective of EuroSCORE. Duration of cardiopulmonary bypass was the most important determinant of re-operation for bleeding. EuroSCORE was predictive of new renal replacement therapy but not mortality.

CONCLUSIONS

Machine-learning algorithms have allowed us to analyse the significance of dynamic processes that occur between pre-operative and peri-operative elements. Length of procedure and duration of cardiopulmonary bypass predicted mortality and morbidity in patients undergoing cardiac surgery in the UK. Bayesian networks can be used to explore potential principle determinant mechanisms underlying outcomes and be used to help develop future risk models.

Impact of atrial fibrillation on in-hospital outcomes among hospitalizations for cardiac surgery: an analysis of the National Inpatient Sample

The short-term impact of atrial fibrillation (AF) on cardiac surgery hospitalizations has been previously reported in cohorts of various sizes, but results have been variable. Using the 2005-2014 National Inpatient Sample, we identified all adult hospitalizations for cardiac surgery using the International Classification of Diseases, Ninth Revision, Clinical Modification as any procedure code and AF as any diagnosis code. We estimated the impact of AF on inpatient mortality, length of stay (LOS), and cost of hospitalization using survey-weighted, multivariable logistic, accelerated failure-time log-normal, and log-transformed linear regressions, respectively. Additionally, we exact-matched AF to non-AF hospitalizations on various confounders for the same outcomes. A total of 1,269,414 hospitalizations were noted for cardiac surgery during the study period. Coexistent AF was found in 44.9% of these hospitalizations. Overall mean age was 65.6 years, 40.9% were female, mean LOS was 11.6 days, and inpatient mortality was 4.5%. Stroke rate was lower in AF hospitalizations (1.8% vs 2.1%, p<0.001). Mortality was lower in the AF (3.9%) versus the non-AF (5%) group (exact-matched OR or emOR=0.48, 95% CI 0.29 to 0.80, p<0.001; 987 matched pairs, n=2423), with similar results after procedural stratification: isolated valve replacement/repair (emOR=0.38, p<0.001), isolated coronary artery bypass graft (CABG) (emOR=0.33, p<0.001), and CABG with valve replacement/repair (emOR=0.55, p<0.001). A 12% increase was seen in LOS in the AF subgroup (exact-matched time ratio=1.12, 95% CI 1.10 to 1.14, p<0.001) among hospitalizations which underwent valve replacement/repair with or without CABG. Hospitalizations for cardiac surgery which had coexistent AF were found to have lower inpatient mortality risk and stroke prevalence but higher LOS and hospitalization costs compared with hospitalizations without AF.

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.

Optimizing cerebral perfusion and hemodynamics during cardiopulmonary bypass through cannula design combining in silico, in vitro and in vivo input

Cardiopulmonary bypass (CPB) is a standard technique for cardiac surgery, but comes with the risk of severe neurological complications (e.g. stroke) caused by embolisms and/or reduced cerebral perfusion. We report on an aortic cannula prototype design (optiCAN) with helical outflow and jet-splitting dispersion tip that could reduce the risk of embolic events and restores cerebral perfusion to 97.5% of physiological flow during CPB in vivo, whereas a commercial curved-tip cannula yields 74.6%. In further in vitro comparison, pressure loss and hemolysis parameters of optiCAN remain unaffected. Results are reproducibly confirmed in silico for an exemplary human aortic anatomy via computational fluid dynamics (CFD) simulations. Based on CFD simulations, we firstly show that optiCAN design improves aortic root washout, which reduces the risk of thromboembolism. Secondly, we identify regions of the aortic intima with increased risk of plaque release by correlating areas of enhanced plaque growth and high wall shear stresses (WSS). From this we propose another easy-to-manufacture cannula design (opti²CAN) that decreases areas burdened by high WSS, while preserving physiological cerebral flow and favorable hemodynamics. With this novel cannula design, we propose a cannulation option to reduce neurological complications and the prevalence of stroke in high-risk patients after CPB.

Factors associated with long-term survival in patients with stroke after coronary artery bypass grafting

Objective

Occurrence of a stroke within 30 days following coronary artery bypass grafting (CABG) is an uncommon, but often devastating, complication. This study aimed to identify factors associated with long-term survival (beyond 30 days) in patients with stroke after CABG.

Methods

De-identified patients’ records from the Veterans Affairs Surgical Quality Improvement Program database were used to identify risk factors and perioperative complications associated with survival for up to 20 years in patients with post-CABG stroke. The multivariable Cox proportional hazards model was used for analyzing survival.

Results

The median survival time for patients with stroke (n = 1422) was 6.7 years. The mortality rate for these patients was highest in the first year post-CABG and was significantly elevated compared with non-stroke patients. Survival rates at 1, 5, and 10 years for stroke versus non-stroke patients were 79% vs. 96%, 58% vs. 83%, and 36% vs. 63%, respectively. High preoperative serum creatinine levels, postoperative occurrence of renal failure, prolonged ventilation, coma, and reoperation for bleeding were important predictors of 1-year mortality of patients with post-CABG stroke.

Conclusions

Veterans with post-CABG stroke have a considerably higher risk for mortality during the first year compared with patients without stroke.

Impact of postoperative complications after cardiac surgery on long-term survival

PURPOSE

The impact of postoperative complications on long-term survival is not well characterized. We sought to study the prevalence of postoperative complications after cardiac surgery and their impact on long-term survival.

METHODS

Operative survivors (n = 26,221) who underwent coronary artery bypass grafting (CABG) (n = 13,054, 49.8%), valve surgery (n = 8667, 33.1%) or combined CABG and valve surgery (n = 4500, 17.2%) from 1993 to 2019 were included in the study. Records were reviewed for postoperative complications and long-term survival. Propensity-match analysis was performed between patients who did and did not have a postoperative complication. The associations between postoperative complications and survival were assessed using a Cox-proportional model.

RESULTS

Complications occurred in 17,463 (66.6%) of 26,221 operative survivors. A total of 17 postoperative complications were analyzed. Postoperative blood product use was the commonest (n = 12,397, 47.3%), followed by atrial fibrillation (n = 8399, 32.0%), prolonged ventilation (n = 2336, 8.9%), renal failure (n = 870, 3.3%), reoperation for bleeding (n = 859, 3.3%) and pacemaker/ICD insertion (n = 795, 3.0%). Stroke (hazard ratio [HR]: 1.55; 95% confidence interval [CI]: 1.36-1.77), renal failure (HR: 1.45; 95% CI: 1.33-1.58) and pneumonia (HR: 1.23; 95% CI: 1.11-1.36) had the strongest impact on long-term survival. Long-term survival decreased as the number of postoperative complications increased.

CONCLUSIONS

Postoperative complications after cardiac surgery significantly impact outcomes that extend beyond the postoperative period. Stroke, renal failure, and pneumonia are particularly associated with poor long-term survival.

Lawrence K. Optical monitoring of cerebral perfusion and metabolism in adults during cardiac surgery with cardiopulmonary bypass

During cardiac surgery with cardiopulmonary bypass (CPB), adequate maintenance of cerebral blood flow (CBF) is vital in preventing postoperative neurological injury - i.e. stroke, delirium, cognitive impairment. Reductions in CBF large enough to impact cerebral energy metabolism can lead to tissue damage and subsequent brain injury. Current methods for neuromonitoring during surgery are limited. This study presents the clinical translation of a hybrid optical neuromonitor for continuous intraoperative monitoring of cerebral perfusion and metabolism in ten patients undergoing non-emergent cardiac surgery with non-pulsatile CPB. The optical system combines broadband near-infrared spectroscopy (B-NIRS) to measure changes in the oxidation state of cytochrome c oxidase (oxCCO) - a direct marker of cellular energy metabolism - and diffuse correlation spectroscopy (DCS) to provide an index of cerebral blood flow (CBFi). As the heart was arrested and the CPB-pump started, increases in CBFi (88.5 ± 125.7%) and significant decreases in oxCCO (-0.5 ± 0.2 µM) were observed; no changes were noted during transitions off CPB. Fifteen hypoperfusion events, defined as large and sustained reductions in CPB-pump flow rate, were identified across all patients and resulted in significant decreases in perfusion and metabolism when mean arterial pressure dropped to 30 mmHg or below. The maximum reduction in cerebral blood flow preceded the corresponding metabolic reduction by 18.2 ± 15.0 s. Optical neuromonitoring provides a safe and non-invasive approach for assessing intraoperative perfusion and metabolism and has potential in guiding patient management to prevent adverse clinical outcomes.

Neurological Complications After Transcatheter Versus Surgical Aortic Valve Replacement in Intermediate-Risk Patients

BACKGROUND

Neurological events after aortic valve interventions are associated with increased mortality and morbidity. Transcatheter aortic valve replacement (TAVR) is increasingly offered for lower-risk patients with severe aortic stenosis, previously considered candidates for surgical aortic valve replacement (SAVR). Differences in post-procedural neurological events have important implications in treatment allocation.

OBJECTIVES

The authors sought to analyze the neurological events in the randomized SURTAVI (Surgical Replacement and Transcatheter Aortic Valve Implantation) trial.

METHODS

Patients with severe, symptomatic aortic stenosis at intermediate surgical risk were randomized 1:1 to TAVR or SAVR. The rates of neurological events and quality of life were analyzed at 30 days, and 6 and 12 months post-procedure in a modified intention-to-treat population (mean age 79.8 ± 6.2 years; N = 1,660).

RESULTS

The rates of early (30-day) stroke and post-procedural encephalopathy were higher after SAVR versus TAVR (5.4% vs. 3.3%; p = 0.031; and 7.8% vs. 1.6%; p < 0.001, respectively). At 12 months, the rate of stroke was not different between SAVR and TAVR (6.9% vs. 5.2%; p = 0.136). Early stroke and early encephalopathy resulted in an elevated mortality at 12 months in both treatment groups. Quality of life after an early stroke was significantly lower in SAVR versus TAVR patients at 30 days and was similar at 6 and 12 months.

CONCLUSIONS

The early stroke rate was lower after TAVR than SAVR. In patients with early strokes, QOL improved earlier after TAVR. At 12-month follow-up, stroke rates and QOL were not different between TAVR and SAVR patients. (Surgical Replacement and Transcatheter Aortic Valve Implantation [SURTAVI]; NCT01586910).

Consequence of Ischemic Stroke after Coronary Surgery with Cardiopulmonary Bypass According to Stroke Subtypes

Introduction

The aim of this study was to determine the outcomes of patients developing ischemic stroke after coronary artery bypass grafting (CABG).

Methods

From March 2012 to January 2017, 5380 consecutive patients undergoing elective coronary surgery were analyzed. Ninety-five patients who developed ischemic strokes after on-pump coronary surgery were included in the study, retrospectively. The cohort was divided into four subgroups [total anterior circulation infarction (TACI), partial anterior circulation infarction (PACI), posterior circulation infarction (POCI), and lacunar infarction (LACI)] according to the Oxfordshire Community Stroke Project (OCSP) classification. The primary endpoints were in-hospital mortality, total mortality, and survival analysis over an average of 30 months of follow-up. The secondary endpoints were the extent of disability and dependency according to modified Rankin Scale (mRS).

Results

The incidence of stroke was 1.76% (n=95). The median age was 62.03±10.06 years and 68 (71.6%) patients were male. The groups were as follows: TACI (n=17, 17.9%), PACI (n=47, 49.5%), POCI (n=20, 21.1%), and LACI (n=11, 11.6%). Twenty-eight (29.5%) patients died in hospital and 34 (35.8%) deaths occurred. The overall mortality rate of the TACI group was significantly higher than that of the LACI group (64.7% vs. 27.3%, P=0.041). The mean mRS score of the TACI group was significantly higher than that of the other groups (P=0.003).

Conclusion

Patients in the TACI group had higher in-hospital and cumulative mortality rates and higher mRS scores. We believe that use of the OCSP classification and the mRS may render it possible to predict the outcomes of stroke after coronary surgery.

Neurological complications after cardiac surgery: a retrospective case-control study of risk factors and outcome

Background

To evaluate incidence, risk factors, and outcomes of postoperative neurological complications in patients undergoing cardiac surgery.

Methods

A total of 2121 patients underwent cardiac surgery between August, 2008 and December, 2013; 91/2121 (4.3%) underwent brain computed tomography (70/91, 77%) or magnetic resonance imaging (21/91, 23%) scan because of major stroke (37/2121, 1.7%) and a spectrum of transient neurological episodes as well as transient ischemic attacks and delirium /psychosis/seizures (54/2121, 2.5%). The mean age was 65.3 ± 12.1 years and 60 (65.9%) were male. Variables were compared among study- and matched-patients (n = 113) without neurological deficits.

Results

A total of 37/2121 (1.7%) patients had imaging evidence of stroke. Radiological examinations were done 5.72 ± 3.6 days after surgery. Patients with and without imaging evidence of stroke had longer intensive care unit length of stay (LOS) (13.8 ± 14.7 and 12.9 ± 15 days vs. 5.7 ± 12.1 days, respectively (p < 0.001) and hospital LOS (53 ± 72.8 and 35.5 ± 29.8 days vs. 18.4 ± 29.2 days, respectively (p < 0.001) than the control group. The hospital mortality of patients with and without imaging evidence of stroke was higher than the control group (7/37 patients [19%], and 12/54 patients [22%] vs. 4/115 patients [3%], respectively (p < 0.001). Multivariate analysis showed that bilateral internal carotid artery stenosis of any grade (p < .001), and re-do operations (p = .013) increased the risk of postoperative neurological complications.

Conclusions

Neurological complications after cardiac surgery increase hospitalization and mortality even in patients without radiologic evidence of stroke. Bilateral internal carotid artery stenosis of any grade, suggesting a diffuse patient propensity toward atherosclerosis, and re-do operations increase the risk of postoperative neurological complications.

Computer-Simulated Fluid Dynamics of Arterial Perfusion in Extracorporeal Circulation: From Reality to Virtual Simulation

Background

Atheroembolism due to aortic manipulation remains an unsolved problem in surgery for thoracic aortic aneurysm. The goal of the present study is to create a computer simulation (CS) model with which to analyze blood flow in the diseased aorta.

Method

A three-dimensional glass model of the aortic arch was constructed from CT images of a normal, healthy person and a patient with transverse aortic arch aneurysm. Separately, a CS model of the curved end-hole cannula was created, and flow from the aortic cannula was recreated using a numerical simulation.

Results

Comparison of the data obtained by the glass model analyses revealed that the flow velocity and the vector of the flow around the exit of the cannula were similar to that in the CS model. A high-velocity area was observed around the cannula exit in both the glass model and the CS model. The maximum flow velocity was as large as 1.0 m/s at 20 mm from the cannula exit and remained as large as 0.5 to 0.6 m/s within 50 mm of the exit. In the aortic arch aneurysm models, the rapid jet flow from the cannula moved straight toward the lesser curvature of the transverse aortic arch. The locations and intensities of the calculated vortices were slightly different from those obtained for the glass model.

Conclusions

The proposed CS method for the analysis of blood flow from the aortic cannulae during extracorporeal circulation can reproduce the flow velocity and flow pattern in the proximal and transverse aortic arches.

Carotid artery stenosis as an independent risk factor for perioperative strokes following mitral valve surgical intervention

OBJECTIVE

To examine the role of carotid stenosis (CS) and other independent risk factors of perioperative stroke following either mitral valve repair or replacement.

METHODS

Using data from the National Inpatient Sample (NIS) database for analysis, all patients who underwent either mitral valve repair or replacement were identified using ICD-9 codes.

RESULTS

A total of 79,583 patients who underwent either mitral valve replacement or repair were studied. 3.39% of the total cohort developed perioperative stroke. With a mean age of 62.78±0.23, there was a statistically significant amount of stroke cases in age ranges 65-74 and 75-84 (p<0.05). Risk stratification was done using Van Walraven (VWR) scoring and the cohort had a mean of 2.73±0.06. The following independent predictors were found to be significant: age, female gender, moderate and high VWR risk, both symptomatic and asymptomatic CS, atrial fibrillation, previous h/o smoking, and other cardiac valve procedures performed, and congestive heart failure (CHF).

CONCLUSION

CS is a significant risk factor for perioperative strokes following mitral valve surgery. Further prospective clinical studies are needed that look into risk stratification of patients for better patient selection and the question of whether carotid revascularization procedures will be beneficial in reducing stroke rates.

Carotid artery disease and perioperative stroke risk after surgical aortic valve replacement: A nationwide inpatient sample analysis

To study the role of carotid stenosis (CS) and cerebrovascular disease as independent risk factors for perioperative stroke following surgical aortic valve replacement (SAVR). The National Inpatient Sample (NIS) database was used for our study. All patients who underwent SAVR from 1999 to 2011 were identified using ICD-9 codes. Univariate and multivariate analysis of baseline characteristics, Elixhauser comorbidities and other covariates were examined to identify independent predictors of perioperative strokes following SAVR. Data on 50,979 patients who underwent SAVR from 1999 to 2011 was obtained. The mean age of the study cohort was 60.5. The study patients were predominantly Caucasian (79.3%) and males (60.01%). The incidence of perioperative stroke was 2.48%. CS (OR 1.8, 95%CI 1.1-2.8, p=0.009) and cerebral arterial occlusion (OR 3.4, 95% CI 1.3-8.9) significantly increased perioperative stroke risk following SAVR. Infective endocarditis (OR 4.6, 95%CI 3.8-5.6, p=0.00) and neurological disorders (OR 4.8, 95% CI 4-5.8, p=0.00) appeared to be the strongest risk factors for strokes. Other risk factors found to be significant predictors of perioperative strokes (p<0.05) were - age, higher VWR scores, CS, cerebral arterial occlusion, infective endocarditis, DM, HTN, renal failure, neurological disorders, coagulopathy and hypothyroidsm. In conclusion, perioperative stroke risk has remained more or less constant despite advancements in surgical techniques with risk having gone up in patients <65years of age. CS and cerebral arterial occlusion significantly increase stroke risk following SAVR. Improved patient selection with pre-operative risk stratification and institution of preventive strategies are necessary to improve operative outcomes following SAVR.

Current outcomes of off-pump coronary artery bypass grafting: evidence from real world practice

Coronary artery bypass grafting (CABG) can be performed conventionally using cardiopulmonary bypass (CPB) and aortic clamping or on a beating heart (BH) without the use of CPB, the so-called off-pump CABG. Some surgeons, who are proponents of off-pump CABG, preferentially use this technique for the majority of operations, whereas others use it only in certain situations which warrant avoidance of CPB. Ever since the conception of off-pump CABG, the never-ending debate about which technique of CABG is safe and efficacious continues to date. Several randomized controlled trials (RCTs) have been conducted that have either favored on-pump CABG or have failed to show a significant difference in outcomes between the two techniques. However, these RCTs have been fraught with claims that they do not represent the majority of patients undergoing CABG in real world practice. Therefore, assessment of the benefits and drawbacks of each technique through observational and registry studies would be more representative of patients encountered in daily practice. The present review examines various retrospective studies and meta-analyses of observational studies that compare the early and long-term outcomes of off- and on-pump CABG, which assesses their safety and efficacy. Additionally, their outcomes in older patients, females, and those with diabetes mellitus, renal dysfunction, presence of ascending aortic disease, and/or acute coronary syndrome (ACS) have also been discussed separately. The general consensus is that early results of off-pump CABG are comparable to or in some cases better than on-pump CABG. However, on-pump CABG provides a survival benefit in the long term according to a majority of publications in literature.

Sonolysis in Prevention of Brain Infarction During Cardiac Surgery (SONORESCUE): Randomized, Controlled Trial

Here, we examined whether intraoperative sonolysis can alter the risk of new ischemic lesions in the insonated brain artery territory during coronary artery bypass grafting (CABG) or valve surgery.Silent brain ischemic lesions could be detected in as many as two-thirds of patients after CABG or valve surgery.Patients indicated for CABG or valve surgery were allocated randomly to sonolysis (60 patients, 37 males; mean age, 65.3 years) of the right middle cerebral artery (MCA) during cardiac surgery and control group (60 patients, 37 males; mean age, 65.3 years). Neurologic examination, cognitive function tests, and brain magnetic resonance imaging (MRI) were conducted before intervention as well as 24 to 72 hours and 30 days after surgery.New ischemic lesions on control diffusion-weighted MRI in the insonated MCA territory ≥0.5 mL were significantly less frequent in the sonolysis group than in the control group (13.3% vs 26.7%, P = 0.109). The sonolysis group exhibited significantly reduced median volume of new brain ischemic lesions (P = 0.026). Stenosis of the internal carotid artery ≥50% and smoking were independent predictors of new brain ischemic lesions ≥0.5 mL (odds ratio = 5.685 [1.272-25.409], P = 0.023 and 4.698 [1.092-20.208], P = 0.038, respectively). Stroke or transient ischemic attack occurred only in 2 control patients (P = 0.496). No significant differences were found in scores for postintervention cognitive tests (P > 0.05).This study provides class-II evidence that sonolysis during CABG or valve surgery reduces the risk of larger, new ischemic lesions in the brain.www.clinicaltrials.gov (NCT01591018).

The Effect of Dexmedetomidine on Outcomes of Cardiac Surgery in Elderly Patients

OBJECTIVE

The goal of this retrospective study was to investigate the effects of perioperative use of dexmedetomidine (Dex) on outcomes for older patients undergoing cardiac surgery.

DESIGN

Retrospective investigation.

SETTING

Patients from a single tertiary medical center.

PARTICIPANTS

A total of 505 patients (≥65 years old) who underwent coronary artery bypass graft (CABG) or valve surgery. CABG and/or valve surgery plus other procedures were divided into 2 groups: 283 received intravenous Dex infusion (Dex group) and 222 did not (Non-Dex group).

INTERVENTIONS

Perioperative Dex intravenous infusion (0.24 to 0.6 μg/kg/h) initiated after cardiopulmonary bypass and continued for<24 hours postoperatively in the ICU.

MEASUREMENTS AND MAIN RESULTS

Data were risk adjusted, propensity score weighted, and multivariate logistic regression was used. The primary outcome was mortality. Secondary outcomes included postoperative stroke, coma, myocardial infarction, heart block, cardiac arrest, delirium, renal failure, and sepsis. Perioperative Dex infusion significantly decreased in-hospital mortality (0.90% v 2.83%; adjusted odds ratio (OR), 0.099; 95% confidence interval (CI), 0.030-0.324; p = 0.004) and operative mortality (1.35% v 3.18%; adjusted OR, 0.251; 95% CI, 0.077-0.813; p = 0.021). Perioperative Dex treatment also reduced the risk of stroke (0.90% v 1.77%; adjusted OR, 0.15; 95% CI, 0.038-0.590; p = 0.007), and delirium (7.21% v 10.95%; adjusted OR, 0.35; 95% CI, 0.212-0.578; p < 0.0001).

CONCLUSIONS

Results from this study (ClinicalTrials.gov identifier: NCT01683448) suggested perioperative use of dexmedetomidine was associated with decreases in in-hospital and operative mortality in elderly patients following cardiac surgery. It also reduced incidences of postoperative stroke and delirium in elderly patients.

Imaging Techniques for Diagnosis of Thoracic Aortic Atherosclerosis

The most severe complications after cardiac surgery are neurological complications including stroke which is often caused by emboli merging from atherosclerosis in the ascending aorta to the brain. Information about the thoracic aorta is crucial in reducing the embolization risk for both surgical open and closed chest procedures such as transaortic heart valve implantation. Several techniques are available to screen the ascending aorta, for example, transesophageal echocardiography (TEE), epiaortic ultrasound, TEE A-view method, manual palpation, computed tomography, and magnetic resonance imaging. This paper provides a description of the advantages and disadvantages of these imaging techniques.

Usefulness of the CHA2DS2VASc score to predict postoperative stroke in patients having cardiac surgery independent of atrial fibrillation

Despite its association with cardioembolic stroke, atrial fibrillation (AF) appears to be inconsistent as a risk factor for postoperative strokes in patients who underwent cardiac surgery. Furthermore, the relation between AF and the CHA2DS2VASc score has not been definitively established with respect to postoperative stroke. We retrospectively analyzed the records of all cardiac surgery performed at our institution between January 2008 and July 2013. Baseline characteristics, operative data, and postoperative outcomes were compared in patients who developed stroke with those who did not. Previously recognized stroke risk factors, including AF, were analyzed along with the CHADS2 and CHA2DS2VASc scores. A total of 3,492 consecutive patients were identified, of which 2,077 (60%) underwent valve surgery, 915 (26%) had coronary artery bypass grafting, 399 (11%) underwent combined coronary artery bypass grafting and valve procedures, and 101 (3%) had other cardiac operations. Postoperative ischemic strokes occurred in 44 patients (1.2%). The development of a stroke was associated with older age (74 ± 12 vs 69 ± 12, p = 0.008), preoperative antiplatelet medication use (38.6% vs 24.5%, p = 0.043), congestive heart failure (37% vs 20%, p = 0.002), and greater CHADS2 (2.48 ± 1.3 vs 1.98 ± 1.1, p = 0.015) and CHA2DS2VASc scores (4.2 ± 1.8 vs 3.4 ± 1.6, p = 0.002). Multivariable analysis demonstrated that the CHA2DS2VASc score was the only independent predictor of postoperative strokes (odds ratio 1.25; 95% confidence interval 1.05 to 1.5, p = 0.014). In conclusion, the CHA2DS2VASc score appears to predict postoperative strokes independent of the presence of AF.

Preventive effect of intraoperative landiolol administration on atrial fibrillation after off-pump coronary artery bypass grafting

INTRODUCTION

Postoperative atrial fibrillation (AF) is a common complication of cardiac surgery that is associated with an increased incidence of other complications. This study evaluated the safety and efficacy of landiolol hydrochloride--an ultrashort-acting β1-selective blocker and highly regulated drug, positioned as a class 1 antiarrhythmic in Japan guidelines--for the prevention of AF after off-pump coronary artery bypass grafting (CABG).

METHODS

Between January 2011 and November 2013, 116 patients underwent CABG at Fukuoka University Hospital. They were divided into two groups: group L consisted of patients who were administered landiolol hydrochloride at 2 μg/kg/min after completion of all distal anastomoses; group C was the control group consisting of patients who were not administered landiolol. Patient backgrounds, intraoperative variables and incidence of postoperative complications were compared.

RESULTS

No significant between-group differences were observed in patient backgrounds or incidence of complications other than postoperative AF, which occurred significantly less frequently in group L. After administration of landiolol, heart rate decreased but no change was observed in arterial pressure or other parameters, and patient hemodynamics remained stable.

CONCLUSION

Intraoperative and perioperative administration of low-dose landiolol has a preventive effect on the development of AF after CABG surgery.

Electrophysiological changes preceding the onset of atrial fibrillation after coronary bypass grafting surgery

BACKGROUND

The incidence of Post-CABG atrial fibrillation (AF) lies between 25% and 40%. It worsens morbidity and raises post-operative costs. Detection of incoming AF soon enough for prophylactic intervention would be helpful. The study is to investigate the electrophysiological changes preceding the onset of AF and their relationship to the preoperative risk.

METHODS AND RESULTS

Patients were recorded continuously for the first four days after coronary artery bypass grafting surgery (CABG) with three unipolar electrodes sutured to the atria (AEG). The patients experiencing an AF lasting more than 10 minutes were selected and the two hours before the onset were analyzed. Four variables were found to show significant changes in the two hours prior to the first prolonged AF: increasing rate of premature atrial activation, increasing incidence of short transient arrhythmias, acceleration of heart rate, and rise of low frequency content of heart rate. The main contrast was between the first and last hour before AF onset. Preoperative risk was not predictive of the onset time of AF and did not correlate with the amplitude of changes prior to AF.

CONCLUSIONS

Post-CABG AF were preceded by electrophysiological changes occurring in the last hour before the onset of the arrhythmia, whereas none of these changes was found to occur in all AF patients. The risk was a weighted sum of factors related to the density of premature activations and the state of atrial substrate reflected by the sinus rhythm and its frequency content prior to AF. Preoperative risk score seems unhelpful in setting a detection threshold for the AF onset.

Impact of concomitant coronary artery disease on atherosclerotic plaques in the aortic arch in patients with severe aortic stenosis

BACKGROUND

Coronary artery disease (CAD) often occurs concurrently in patients with severe aortic stenosis (AS). However, the influence of concomitant CAD on the presence of atherosclerotic complex plaques in the aortic arch, which is associated with increased stroke risk, has not been fully assessed in patients with severe AS.

HYPOTHESIS

We hypothesized that concomitant CAD would be associated with the presence of complex arch plaques in patients with severe AS.

METHODS

The study population consisted of 154 patients with severe AS who had undergone transesophageal echocardiography (TEE) and coronary angiography (71 male; mean age, 72 ± 8 years; mean aortic valve area, 0.67 ± 0.15 cm(2) ). Aortic arch plaques were assessed using TEE, and complex arch plaques were defined as large plaques (≥4 mm), ulcerated plaques, or mobile plaques.

RESULTS

The prevalence of aortic arch plaques (87% vs 70%; P = 0.03) and complex arch plaques (48% vs 20%; P < 0.001) was significantly greater in AS patients with CAD than in those without CAD. After adjustment for traditional atherosclerotic risk factors, we found that concomitant CAD was independently associated with the presence of complex arch plaques (odds ratio: 2.86, 95% confidence interval: 1.23-6.68, P = 0.01).

CONCLUSIONS

In patients with severe AS, concomitant CAD is associated with severe atherosclerotic burden in the aortic arch. This observation suggests that AS patients with concomitant CAD are at a higher risk for stroke, and that careful evaluation of complex arch plaques by TEE is needed for the risk stratification of stroke in these patients.

From accuracy to patient outcome and cost-effectiveness evaluations of diagnostic tests and biomarkers: an exemplary modelling study

BACKGROUND

Proper evaluation of new diagnostic tests is required to reduce overutilization and to limit potential negative health effects and costs related to testing. A decision analytic modelling approach may be worthwhile when a diagnostic randomized controlled trial is not feasible. We demonstrate this by assessing the cost-effectiveness of modified transesophageal echocardiography (TEE) compared with manual palpation for the detection of atherosclerosis in the ascending aorta.

METHODS

Based on a previous diagnostic accuracy study, actual Dutch reimbursement data, and evidence from literature we developed a Markov decision analytic model. Cost-effectiveness of modified TEE was assessed for a life time horizon and a health care perspective. Prevalence rates of atherosclerosis were age-dependent and low as well as high rates were applied. Probabilistic sensitivity analysis was applied.

RESULTS

The model synthesized all available evidence on the risk of stroke in cardiac surgery patients. The modified TEE strategy consistently resulted in more adapted surgical procedures and, hence, a lower risk of stroke and a slightly higher number of life-years. With 10% prevalence of atherosclerosis the incremental cost-effectiveness ratio was € 4,651 and € 481 per quality-adjusted life year in 55-year-old men and women, respectively. In all patients aged 65 years or older the modified TEE strategy was cost saving and resulted in additional health benefits.

CONCLUSIONS

Decision analytic modelling to assess the cost-effectiveness of a new diagnostic test based on characteristics, costs and effects of the test itself and of the subsequent treatment options is both feasible and valuable. Our case study on modified TEE suggests that it may reduce the risk of stroke in cardiac surgery patients older than 55 years at acceptable cost-effectiveness levels.

Landiolol, an ultra-short-acting β₁-blocker, more effectively terminates atrial fibrillation than diltiazem after open heart surgery: prospective, multicenter, randomized, open-label study (JL-KNIGHT study)

BACKGROUND

Recent studies have suggested that esmolol is the first choice for rate control in patients with postoperative atrial fibrillation (AF) after coronary artery bypass surgery, but side-effects of esmolol such as hypotension are problematic. To overcome this problem, landiolol, an ultra-short-acting β(1)-blocker with a less negative inotropic effect than esmolol, has been developed. The aim of the present study was to investigate whether landiolol was effective for both rate control and conversion to normal sinus rhythm (NSR).

METHODS AND RESULTS

A prospective, randomized, open-label comparison between i.v. landiolol and diltiazem in patients with postoperative AF was undertaken between January 2008 and June 2009 in Japan. Of 335 patients included in the analysis, 71 patients went into AF. Among these 71 patients, conversion to NSR within 8h after onset of AF occurred in 19 of 35 patients (54.3%) in the landiolol group vs. 11 of 36 patients (30.6%) in the diltiazem group (P<0.05). The incidence of hypotension was lower in the landiolol group (4/35, 11.4%) compared with the diltiazem group (11/36, 30.6%; P<0.05). The incidence of bradycardia was also lower in the landiolol group (0%) compared with the diltiazem group (4/36, 11.1%; P<0.05).

CONCLUSIONS

Landiolol is more effective and safer than diltiazem for patients with postoperative AF after open heart surgery.

Risk of Stroke After Coronary Artery Bypass Grafting

Background and Purpose—

The risk of stroke after coronary artery bypass grafting (CABG) is known to increase dramatically with age. During recent years, the age of patients operated on has increased and concomitant therapy has changed. Therefore, we have re-evaluated the risk of stroke after CABG.

Methods—

Through the Danish National Hospital Register, we identified all 25 159 patients with isolated CABG from 1997 through 2006. Stroke, comorbidities, and medication were further obtained. Risk factors of stroke were determined through regression models.

Results—

Overall, 1901 patients (7.6%) suffered a stroke after surgery, 477 patients (2.0%) within 30 days after CABG. Rates of stroke per 100 person-years (95% CI) within 30 days after surgery increased with age: <60 years, 10.1 (7.8–13.0); 60 to 64 years, 18.4 (14.3–23.5); 65 to 69 years, 27.7 (23.0–33.3); 70 to 74 years, 36.0 (30.4–42.6); 75 to 79 years, 36.1 (29.1–44.7); ≥80 years, 38.0 (25.2–57.1). Risks of stroke within 30 days after surgery adjusted for age (reference: age <60 years), sex, relevant comorbidities, and selected medication included: 60 to 64 years: HR, 1.7 ( P =0.005; 95% CI, 1.2–2.4), 65 to 69 years: HR, 2.4 ( P =0.001; 95% CI, 1.7–3.3), 70 to 74 years: HR, 2.8 ( P =0.001; 95% CI, 2.1–3.8), 75 to 79 years: HR, 2.8 ( P =0.001; 95% CI, 2.0–4.0), ≥80 years: HR, 3.0 ( P =0.001; 95% CI, 1.8–4.9), previous stroke: HR, 4.2 ( P =0.001; 95% CI, 3.3–5.4), diabetes: HR, 1.3 ( P =0.019; 95% CI, 1.1–1.7), hypertension: HR, 1.4 ( P =0.003; 95% CI, 1.1–1.7), peripheral vascular disease: HR, 1.6 ( P =0.001; 95% CI, 1.3–2.1), renal failure: HR, 1.7 ( P =0.012; 95% CI, 1.1–2.5), statins: HR, 0.8 ( P =0.049; 95% CI, 0.7–1.0), clopidogrel: HR, 0.6 ( P =0.032; 95% CI, 0.4–1.0).

Conclusions—

The increase in stroke with age after CABG is moderate and the relation uncertain in ages older than 70 years. Declining CABG in elderly patients because of risk of stroke purely on the basis of high age is debatable.

Outcomes in patients with symptomatic cerebrovascular disease undergoing heart transplantation

OBJECTIVES

We sought to determine outcomes in patients with and without symptomatic cerebrovascular disease (sCVD) undergoing heart transplantation. Second, we sought to determine factors associated with stroke in the perioperative period after heart transplantation.

BACKGROUND

sCVD is considered a relative contraindication to heart transplantation. Despite this concern, outcomes in patients with sCVD undergoing heart transplantation have not been well defined.

METHODS

Data on all single-organ heart transplants performed in the United States between April 1994 and December 2006 in patients age 40 years or older were analyzed. Survival analysis was performed to examine the effect of sCVD on the combined outcome of stroke or death, stroke, death, and functional decline, adjusting for potential confounding variables over long-term follow-up. In a separate analysis, predictors of perioperative stroke during the transplant-related hospitalization were examined using multiple logistic regression.

RESULTS

There were 1,078 patients with and 16,765 patients without sCVD. The annualized rates of stroke or death (11.5% vs. 7.8%; p < 0.001), stroke (4% vs. 1.4%; p < 0.001), death (8.9% vs. 7.4%; p < 0.001), and functional decline (3.7% vs. 3.0%; p = 0.002) were higher in patients with sCVD than in patients without sCVD. In multivariable analysis, patients with sCVD were at increased risk of stroke or death (hazard ratio [HR]: 1.29; 95% confidence interval [CI]: 1.17 to 1.42), stroke (HR: 2.24; 95% CI: 2.02 to 2.87), and functional decline (HR: 1.21; 95% CI: 1.03 to 1.42) compared with those without sCVD. We did not identify a higher risk of death in patients with sCVD (HR: 1.08; 95% CI: 0.98 to 1.20), compared with those without sCVD. sCVD, ventilator use, and ventricular assist device use were the most important predictors of perioperative stroke.

CONCLUSIONS

Patients with sCVD are at an increased risk of stroke and functional decline after transplantation independent of other variables, but not death, during long-term follow-up. These results should assist programs in making informed decisions in patients with sCVD who are undergoing evaluation for heart transplantation.

Silent meningioma - a rare cause of stroke in post-cardiopulmonary bypass patients

Stroke in cardiac patients undergoing surgery is usually attributed to the use of cardiopulmonary bypass. In this report, we present an unusual cause of cerebral dysfunction: a meningioma leading to stroke, following coronary artery bypass grafting in a 62-year-old patient. Diagnosis and treatment options of the pathology are discussed with the guidance of the literature.

Implementation and efficacy of selective sonographic screening for carotid disease before cardiac surgery

BACKGROUND

Preoperative carotid sonography with consecutive preventive strategies might reduce stroke risk during cardiac surgery. Since routine sonography in all patients may be unfeasible, an approach to examine preselected patients was investigated.

METHODS

A prognostic model predicting carotid disease was developed using the clinical data of 1,768 routinely examined patients. It recommended 1,018 of 4,814 patients of a following collective for selective sonography. Patients recommended for preoperative sonography were compared to those selected in clinical practice.

RESULTS

Besides the evaluated predictor variables, a history of syncope/cardiogenic shock and of pulmonary disease was associated with patient selection for sonography in clinical practice, even though both variables were not associated with severe carotid disease. In patients who underwent sonography, although this was not recommended by the prognostic model, severe carotid disease was estimated lower than what was actually detected, suggesting a change in relative relevance of predicting variables along with the change in frequencies of patients' cardiovascular characteristics.

CONCLUSION

Prognostic models for selective screening before cardiac surgery may require reevaluation over time, especially when baseline characteristics used for prediction have changed. Criteria used in clinical practice to select patients for screening may differ from those recommended by investigational studies.

Hydrodynamics of aortic cannulae during extracorporeal circulation in a mock aortic arch aneurysm model

This study was designed to analyze flow pattern, velocity, and strain on the aortic wall of a glass aortic arch aneurysm model during the extracorporeal circulation, and to elucidate the characteristics of flow pattern in three different aortic cannulae. Different patterns of large vortices and helical flow were made by each cannula. With the curved end-hole cannula, the high velocity flow (approximately 0.6-0.8 m/s) was blowing to the aneurismal wall without attenuating the strain rate tensor (approximately 0.2-0.25/s). With the dispersion cannula and the Soft-Flow cannula, cannular jet was attenuated in the ascending aorta creating a large vortex at a velocity less than 0.5 m/s, and the strain rate tensor on the aneurismal wall was small (less than 0.15/s). In conclusion, end-hole cannula should not be used in the operation of aortic arch aneurysm. Dispersion-type aortic cannulae were less invasive on the aortic arch aneurismal wall, but particular attention to alternative cannulation sites should be paid in cases with severe atherosclerosis on the ascending aortic wall.

Impact of early and delayed stroke on in-hospital and long-term mortality after isolated coronary artery bypass grafting

Stroke after coronary artery bypass grafting (CABG) is an infrequent, yet devastating complication with increased morbidity and mortality. We sought to determine risk factors for early (intraoperatively to 24 hours) and delayed (>24 hours to discharge) stroke and to identify their impact on long-term mortality after CABG. We studied 4,140 consecutive patients who underwent isolated CABG from 1992 to 2003. Long-term survival data (mean follow-up 7.4 years) were obtained from the National Death Index. Independent predictors for stroke and in-hospital mortality were determined by multivariate logistic regression analysis including all available preoperative, intraoperative, and postoperative risk factors. Independent predictors for long-term mortality were determined by multivariate Cox regression analysis. One hundred two patients (2.5%) developed early stroke and 36 patients (0.9%) delayed stroke. Independent predictors for early stroke were age, recent myocardial infarction, smoking, femoral vascular disease, body mass index, reoperation for bleeding, postoperative sepsis and/or endocarditis, and respiratory failure, whereas those for delayed stroke were female gender, white race, preoperative renal failure, respiratory failure, and postoperative renal failure. Early stroke was an independent predictor for in-hospital (odds ratio 3.49, 95% confidence interval [CI] 1.56 to 7.80, p = 0.002) and long-term (hazard ratio 1.70, 95% CI 1.30 to 2.21, p <0.001) mortalities. Delayed stroke was not an independent predictor for in-hospital (odds ratio 0.90, 95% CI 0.23 to 3.51, p = 0.878) or long-term (hazard ratio 0.66, 95% CI 0.38 to 1.17, p = 0.156) mortality. In conclusion, risk factors for early in-hospital stroke differ from those of delayed in-hospital stroke after CABG. Early stroke is an independent predictor for in-hospital and long-term mortalities, suggesting the need for a more frequent follow-up and appropriate pharmacologic therapy after discharge.

Incidence, imaging analysis, and early and late outcomes of stroke after cardiac valve operation

The aim of this study was to analyze the incidence, topography, and mechanisms of stroke, independent predictors, and late outcome after cardiac valve operations. We retrospectively analyzed prospectively collected data from 2,808 patients (mean age 63 +/- 15 years, n = 1,610, 55% men) who underwent valve surgery with or without concomitant coronary artery bypass grafting from January 1998 to December 2006. Stroke was defined as any new permanent focal neurologic deficit. Overall incidence of stroke was 2.2% (n = 63) and decreased during the study period from 3.3% (1998 to 2002) to 1.3% (2003 to 2006; p = 0.001). The highest stroke rate was observed after double aortic/mitral valve replacement (5.4%) and valve/coronary artery bypass grafting procedures (3.6%). Brain imaging was positive in 74% (n = 43 of 58) and showed ischemic stroke in all patients and hemorrhagic conversion in 28%. Distribution of acute stroke was large territory embolic artery (n = 33, 77%), watershed (n = 7, 16%), and mixed pattern (n = 3, 7%). Multivariate analysis revealed calcified ascending aorta (odds ratio [OR] 2.7), female gender (OR 2.6), ejection fraction <30% (OR 2.3), diabetes (OR 2.2), age >70 years (OR 2.0), and cardiopulmonary bypass time >120 minutes (OR 3.7) as predictors of stroke. Hospital mortality was 24% and 4.6% in patients with and without stroke, respectively. Survival of stroke patients was 78% and 54% at 1 year and 5 years, respectively, and was significantly decreased compared with patients without stroke. Valve pathology including endocarditis did not influence the incidence of stroke. Intraoperative epiaortic scanning may contribute in decreasing the incidence of this complication and may be warranted in all patients undergoing valvular surgery. In conclusion, stroke after valvular surgery is associated with an increased hospital mortality and morbidity and decreased long-term survival.

Timing of stroke after cardiopulmonary bypass determines mortality

BACKGROUND

Stroke is an important complication of cardiopulmonary bypass (CPB). This study determined if the timing of stroke events after CPB predicted stroke-related mortality or rehabilitation needs at hospital discharge.

METHODS

We performed a retrospective review of 7201 consecutive cardiac surgical patients during a 10-year period and identified 202 strokes. Postoperative stroke after CPB was classified as early (< or = 24 hours) or late (> 24 hours). Data were collected on patient characteristics, intraoperative variables and outcomes, postoperative course, stroke severity, and discharge status, including death from stroke. Logistic regression analysis was used to assess the relationship between the timing of stroke and discharge status after adjusting for clinically relevant factors.

RESULTS

The stroke incidence was 2.8%. Postoperative strokes occurred within 24 hours in 22.8% (46 of 202) and after 24 hours in 77.2% (156 of 202). Factors found in logistic regression analysis to be independently associated with stroke-related death included stroke within 24 hours postoperatively (odds ratio [OR], 9.16; p < 0.0001), preoperative chronic renal insufficiency (OR, 4.46; p = 0.01), and National Institute of Health Stroke Scale (NIHSS) score (OR, 1.16 per NIHSS point increase; p < 0.0001). Among survivors, early stroke was associated with greater rehabilitation needs (p < 0.001).

CONCLUSIONS

Early stroke after CPB is independently associated with higher stroke-related death and is associated with increased need for skilled rehabilitation at discharge. Neuroprotective strategies aimed at reducing early postoperative stroke may positively impact death and neurologic disability after CPB.

Incidence, topography, predictors and long-term survival after stroke in patients undergoing coronary artery bypass grafting

BACKGROUND

Previous studies on stroke after coronary artery bypass grafting (CABG) provide limited data about the timing (early vs delayed) of this event and findings of brain imaging analysis. This information is of significant importance because it provides insight into the etiology of stroke, potentially allowing the development of preventive measures. This study analyzed the incidence and timing of stroke, the topography and mechanisms of cerebral lesions, independent predictors, and late outcome after the occurrence of this complication in patients undergoing CABG.

METHODS

We retrospectively analyzed prospectively collected data from 2985 patients (2064 men [67%]), with a mean age of 66 +/- 11 years, who underwent CABG between January 1998 and December 2006. Stroke was defined as any new permanent focal neurologic deficit (early stroke, < or = 24 hours; delayed, > 24 hours postoperatively).

RESULTS

The incidence of stroke was 1.6% (n = 48) and similar between conventional CABG (1.6%) and off-pump CABG (1.4%). Early stroke occurred in 25 patients (52%). Brain imaging was obtained in 44 patients (92%): 44 had computed tomography, 3 had magnetic resonance imaging. Results were positive in 33 of 44 patients (75%), showing large embolic stroke in 25 (76%), watershed in 5 (15%), and mixed pattern in 3 (9%). Chronic ischemic changes were found in 17 patients. Multivariate analysis revealed extensive aortic calcification (odds ratio [OR], 4.2), previous stroke (OR, 2.2), female sex (OR, 1.9), and congestive heart failure (OR, 2.6) as predictors of stroke. The hospital mortality rate after stroke was 16.7% (n = 8) compared with 1.5% (n = 44) in those without (p < 0.001). The mortality rate was higher in early stroke at 24% (6 of 25) compared with 9% (2 of 23) in late stroke. Survival of stroke patients was 87% at 1 year and 62% at 5 years and was significantly reduced compared with 96% and 85%, respectively, in patients without stroke (p<0.001).

CONCLUSIONS

Most strokes after CABG occurred early after surgery. This complication is associated with an increased hospital mortality and morbidity and reduced long-term survival. The infarction type had no impact on early and late outcome. Preoperative computed tomography scan seems warranted in patients at risk and without any previous history of stroke.

Cerebral ischemic lesions on diffusion-weighted imaging are associated with neurocognitive decline after cardiac surgery

BACKGROUND AND PURPOSE

Improvements in cardiac surgery mortality and morbidity have focused interest on the neurological injury such as stroke and cognitive decline that may accompany an otherwise successful operation. We aimed to investigate (1) the rate of stroke, new ischemic change on MRI, and cognitive impairment after cardiac valve surgery; and (2) the controversial relationship between perioperative cerebral ischemia and cognitive decline.

METHODS

Forty patients (26 men; mean [SD] age 62.1 [13.7] years) undergoing intracardiac surgery (7 also with coronary artery bypass grafting) were studied. Neurological, neuropsychological, and MRI examinations were performed 24 hours before surgery and 5 days (MRI and neurology) and 6 weeks (neuropsychology and neurology) after surgery. Cognitive decline from baseline was determined using the Reliable Change Index.

RESULTS

Two of 40 (5%) patients had perioperative strokes and 22 of 35 (63%) tested had cognitive decline in at least one measure (range, 1 to 4). Sixteen of 37 participants (43%) with postoperative imaging had new ischemic lesions (range, 1 to 17 lesions) with appearances consistent with cerebral embolization. Cognitive decline was seen in all patients with, and 35% of those without, postoperative ischemic lesions (P<0.001), and there was an association between the number of abnormal cognitive tests and ischemic burden (P<0.001).

CONCLUSIONS

We have provided a reliable estimate of the rate of stroke, postoperative ischemia, and cognitive impairment at 6 weeks after cardiac valve surgery. Cognitive impairment is associated with perioperative ischemia and is more severe with greater ischemic load.

Impaired cerebral autoregulation distal to carotid stenosis/occlusion is associated with increased risk of stroke at cardiac surgery with cardiopulmonary bypass

OBJECTIVES

Severe carotid stenosis and occlusion are associated with an increased risk of stroke during and after cardiac surgery with cardiopulmonary bypass. Relevance of an impaired cerebral autoregulation caused by stenosis/occlusion is unknown.

METHODS

We prospectively assessed the incidence of stroke in relation to severity of carotid disease and corresponding autoregulatory reserve in 2797 patients who had coronary artery bypass graft and/or valve surgery with cardiopulmonary bypass. Patients underwent preoperative carotid sonography and, in case of severe extracranial disease, transcranial Doppler sonography with carbon dioxide stimulation to assess cerebrovascular reserve capacity.

RESULTS

Sixty-seven (2.4%) patients had an ischemic stroke, which was fatal in 5. Anterior hemispheric stroke occurred in 42 (1.9%) patients with no/low-grade stenosis, 6 (1.8%) with medium-grade stenosis, 1 (0.6%) with high-grade stenosis/occlusion and normal autoregulation, and 3 (27.3%) with high-grade stenosis/occlusion and exhausted autoregulatory reserve. Increased risk was observed in patients with high-grade stenosis/occlusion and exhausted autoregulatory reserve also after adjustment for potential confounders (adjusted odds ratio [OR] 28.3, 95% confidence interval [CI] 5.8-139.1). Stroke risk was not increased in patients with stenosis/occlusion and normal autoregulation (1.5%, adjusted OR 0.6, 95% CI 0.2-1.6).

CONCLUSIONS

Cerebrovascular reserve capacity evaluated by preoperative transcranial Doppler carbon dioxide testing is a major determinant of stroke risk in patients with carotid artery stenosis/occlusion undergoing cardiac surgery with cardiopulmonary bypass. Its assessment facilitates identification of patients with an excess perioperative stroke risk.

Cerebrovascular accidents in patients with a ventricular assist device

OBJECTIVE

A cerebrovascular accident is a devastating adverse event in a patient with a ventricular assist device. The goal was to clarify the risk factors for cerebrovascular accident.

METHODS

Prospectively collected data, including medical history, ventricular assist device type, white blood cell count, thrombelastogram, and infection, were reviewed retrospectively in 124 patients.

RESULTS

Thirty-one patients (25%) had 48 cerebrovascular accidents. The mean ventricular assist device support period was 228 and 89 days in patients with and without cerebrovascular accidents, respectively (P < .0001). Sixty-six percent of cerebrovascular accidents occurred within 4 months after implantation. Actuarial freedom from cerebrovascular accident at 6 months was 75%, 64%, 63%, and 33% with the HeartMate device (Thoratec Corp, Pleasanton, Calif), Thoratec biventricular ventricular assist device (Thoratec Corp), Thoratec left ventricular assist device (Thoratec), and Novacor device (WorldHeart, Oakland, Calif), respectively. Twenty cerebrovascular accidents (42%) occurred in patients with infections. The mean white blood cell count at the cerebrovascular accident was greater than the normal range in patients with infection (12,900/mm3) and without infection (9500/mm3). The mean maximum amplitude of the thrombelastogram in the presence of infection (63.6 mm) was higher than that in the absence of infection (60.7 mm) (P = .0309).

CONCLUSIONS

The risk of cerebrovascular accident increases with a longer ventricular assist device support period. Infection may activate platelet function and predispose the patient to a cerebrovascular accident. An elevation of the white blood cell count may also exacerbate the risk of cerebrovascular accident even in patients without infection. Selection of device type, prevention of infection, and meticulous control of anticoagulation are key to preventing cerebrovascular accident.

Resolving the blind spot of transoesophageal echocardiography: a new diagnostic device for visualizing the ascending aorta in cardiac surgery

BACKGROUND

Atherosclerosis of the ascending aorta (AA) and stroke after cardiac surgery are related. Knowledge of the location of AA-atherosclerosis pre-sternotomy allows changes in surgical strategy to avoid manipulation of the AA. The gold-standard for assessment of AA-atherosclerosis is intraoperative epiaortic ultrasound scanning (EUS). Transoesophageal echocardiography (TOE) is unable to detect atherosclerosis in the distal AA due to the 'blind spot'. A new method [A-View (Aortic-view) method] using a fluid-filled catheter may enhance the assessment of distal AA-atherosclerosis. The aim of this study was to evaluate whether the A-View method indeed visualizes the distal AA and to assess the safety of this technology.

METHODS

In a cross-sectional diagnostic study, 41 patients undergoing cardiac surgery including sternotomy underwent the same work-up including TOE, the A-View method, EUS, and routine operative monitoring.

RESULTS

With the A-View method, the distal AA was visible in all (100%) patients. There were no clinical important side-effects associated with the use of the A-View catheter; however, in one patient the endotracheal tube was accidentally dislocated leading to a decrease in Sa(O2). Severity of atherosclerosis visualized with the A-View method compared with EUS results showed good agreement between the two methods [Kappa of 0.69 (0.50-0.88)]. The Bland-Altman analysis showed poor agreement in plaque-size measurements (bias 0.05 cm2, limits of agreement - 0.63 to 0.74 cm2).

CONCLUSIONS

The A-View method offers a minimally invasive and safe approach to preoperatively resolving the blind spot of TOE. Compared with EUS, the A-View method yielded satisfactory results in the detection of AA-atherosclerosis. The A-View method seems a promising tool for patients undergoing cardiac surgery to direct surgical management.