Side differences in cerebrovascular accidents after cardiac surgery: a statistical analysis of neurologic symptoms and possible implications for anatomic mechanisms of aortic particle embolization

The role of CDR1as/ciRS-7 in cardio-cerebrovascular diseases

Cerebellar degeneration-related protein 1 antisense RNA (CDR1as), also known as ciRS-7, is a circular natural antisense transcript of CDR1. It is a widely studied and powerful representative of circular RNAs. Based on its widely reported role in cancer, CDR1as is considered one of the most promising biomarkers for diagnosing and treating tumours. However, some recent studies have extensively focused on its regulatory role in cardio-cerebrovascular diseases instead of in tumours. Studies have shown that CDR1as plays a unique role in the occurrence of cardio-cerebrovascular diseases; thus, it may be a potential target for preventing and treating cardio-cerebrovascular diseases. Furthermore, CDR1as has also been found to be related to signal transduction pathways related to inflammatory response, oxidative stress, etc., which may reveal its potential mechanism in cardio-cerebrovascular diseases. However, there is no literature to summarize the role and possible mechanism of CDR1as in cardio-cerebrovascular diseases. Therefore, in the present review, we have comprehensively summarised the latest progress in the biological characteristics, development processes, regulatory mechanisms, and roles of CDR1as in cardio-cerebrovascular diseases, aiming to provide a reference and guidance for future studies.

Acute stroke in patients undergoing coronary artery bypass grafting surgery in acute coronary syndrome: Predictors and outcomes

OBJECTIVES

Coronary artery bypass grafting (CABG) surgery in patients with acute coronary syndrome (ACS) remains a high-risk procedure and is associated with adverse outcomes. The risk factors of acute stroke in the above-mentioned patients stay unclear and some appropriate data is lacking in the literature. Thus, we aimed to investigate the predictors of acute stroke in patients undergoing CABG surgery in ACS.

METHODS

The retrospective single-centre cohort analysis was conducted. All patients (n = 1344) who suffered from acute coronary syndrome and underwent CABG procedure at the University hospital Cologne from June 2011 until October 2019 were included in our study. In order to find the risk factors of acute stroke after bypass surgery, patients were divided into two groups (non-stroke group (n = 1297) and stroke group (n = 47)). In order to even above-mentioned groups propensity score matching (PSM) analysis was performed (non-stroke group (n = 46) and stroke group (n = 46).

RESULTS

Duration of cardiopulmonary bypass (p = .015) and cross clamp time (p = .006) were significantly longer in patients who suffered stroke. Perioperative myocardial infarction was significantly higher (p = .030) in the stroke group. Likewise, the duration of intensive care unit stay (p < .001) and in-hospital stay (p < .001) were significantly longer in patients with stroke. However, the mortality rate did not differ significantly (p = .131) between above-mentioned groups. Univariate and multivariate analysis showed cardiogenic shock (p = .003), peripheral vascular disease (PVD, p = .025) and previous stroke (p = .045) as relevant independent predictors for acute stroke after CABG procedure in patients with ACS.

CONCLUSION

Based on our findings, acute stroke after bypass surgery in patients with ACS is associated with increased mortality and adverse outcomes. Cardiogenic shock, peripheral vascular disease and previous stroke were independent predictors of stroke after CABG procedure. Therefore, preoperative evaluation of potential risk factors may be crucial to improve postoperative results.

Toward stroke-free coronary surgery: The role of the anaortic off-pump bypass technique

Surgical coronary revascularization remains the preferred strategy in a significant portion of patients with coronary artery disease due to superior long-term outcomes. However, there is a significant risk of perioperative neurologic injury that has influenced guideline recommendations. These complications occur in 1%-5% of patients, ranging from overt neurologic deficits with permanent disability, to subtle cerebral defects noted on neuroimaging that may result in slow cognitive and functional decline. The primary mechanism by which these events occur is thromboembolism from manipulation of the ascending aorta. This occurs during cardiopulmonary bypass, aortic cross-clamping, and partial occlusion clamping (side clamp). Elderly patients and patients with aortic atheroma are, therefore, at significantly increased risk. Initial surgical techniques addressed this by aggressively debriding or replacing the ascending aorta during coronary artery bypass grafting (CABG). Strategies then moved toward minimizing aortic manipulation through pump-assisted beating heart surgery and off-pump surgery with partial occlusion clamping or proximal anastomosis devices. Finally, anaortic off-pump CABG aims to avoid all manipulation of the ascending aorta through advanced off-pump grafting techniques combined with in situ and composite grafts. This has been demonstrated to result in the greatest reduction in risk. Establishing successful anaortic off-pump CABG programs requires subspecialization and focused interest groups dedicated to advancing CABG outcomes.

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.

Exclusion Technique for Entire Shaggy Aorta Followed by One-Stage Repair of the Aortic Arch and Descending Aorta

OBJECTIVE

A shaggy aorta is defined as a very extensive atheromatous disease with diffuse ulcers in combination with fragile and mobile debris, and actual thrombus. Multiple embolisation - resulting in permanent neurological deficits, paraplegia and a large area of mesenteric embolisation - attributed to cholesterol atheromatic mobile plaque caused by shaggy aorta needs to be prevented.

METHODS

Complete exclusion of the shaggy aorta from the distal aortic arch to the end of the descending aorta was presented in two cases: a 71-year-old male and a 51-year-old male. Successful one-stage repair of the extended aortic arch and descending aorta was performed using an isolated selective cerebral perfusion technique via sternotomy and left anterior thoracotomy.

RESULTS

There were no neurological or embolic events in the present cases. Contrast-enhanced computed tomography showed good reconstruction of the aortic arch and descending aorta. The patients are still being followed up in the outpatient clinic and have shown no atheromatic embolisation for the past 6 years.

CONCLUSIONS

The exclusion technique for an entire shaggy aorta followed by one-stage repair of the aortic arch and descending aorta is a durable and feasible operation for preventing atheromatous embolisation.

Perioperative Stroke

PURPOSE OF REVIEW

This review overviews perioperative stroke as it pertains to specific surgical procedures.

RECENT FINDINGS

As awareness of perioperative stroke increases, so does the opportunity to potentially improve outcomes for these patients by early stroke recognition and intervention. Perioperative stroke is defined to be any stroke that occurs within 30 days of the initial surgical procedure. The incidence of perioperative stroke varies and is dependent on the specific type of surgery performed. This chapter overviews the risks, mechanisms, and acute evaluation and management of perioperative stroke in four surgical populations: cardiac surgery, carotid endarterectomy, neurosurgery, and non-cardiac/non-carotid/non-neurological surgeries.

Early Versus Delayed Stroke After Cardiac Surgery: A Systematic Review and Meta-Analysis

Background Although it is traditionally regarded as a single entity, perioperative stroke comprises 2 separate phenomena (early/intraoperative and delayed/postoperative stroke). We aimed to systematically evaluate incidence, risk factors, and clinical outcome of early and delayed stroke after cardiac surgery. Methods and Results A systematic review ( MEDLINE , EMBASE , Cochrane Library) was performed to identify all articles reporting early (on awakening from anesthesia) and delayed (after normal awakening from anesthesia) stroke after cardiac surgery. End points were pooled event rates of stroke and operative mortality and incident rate of late mortality. Thirty-six articles were included (174 969 patients). The pooled event rate for early stroke was 0.98% (95% CI 0.79% to 1.23%) and was 0.93% for delayed stoke (95% CI 0.77% to 1.11%; P=0.68). The pooled event rate of operative mortality was 28.8% (95% CI 17.6% to 43.4%) for early and 17.9% (95% CI 14.0% to 22.7%) for delayed stroke, compared with 2.4% (95% CI 1.9% to 3.1%) for patients without stroke ( P<0.001 for early versus delayed, and for perioperative stroke, early stroke, and delayed stroke versus no stroke). At a mean follow-up of 8.25 years, the incident rate of late mortality was 11.7% (95% CI 7.5% to 18.3%) for early and 9.4% (95% CI 5.9% to 14.9%) for delayed stroke, compared with 3.4% (95% CI 2.4% to 4.8%) in patients with no stroke. Meta-regression demonstrated that off-pump was inversely associated with early stroke (β=-0.009, P=0.01), whereas previous stroke (β=0.02, P<0.001) was associated with delayed stroke. Conclusions Early and delayed stroke after cardiac surgery have different risk factors and impacts on operative mortality as well as on long-term survival.

Incidence and etiological mechanism of stroke in cardiac surgery

OBJECTIVE

We studied patients who had experienced a stroke in the postoperative period of cardiac surgery, aiming to analyse their progression and determine the factors that may influence prognosis and treatment.

METHODS

We established a protocol for early detection of stroke after cardiac surgery and collected data on stroke onset and a number of clinical, surgical, and prognostic variables in order to perform a descriptive analysis.

RESULTS

Over the 15-month study period we recorded 16 strokes, which represent 2.5% of the patients who underwent cardiac surgery. Mean age in our sample was 69 ± 8 years; 63% of patients were men. The incidence of stroke in patients aged 80 and older was 5.1%. Five patients (31%) underwent emergency surgery. By type of cardiac surgery, 7% of patients underwent mitral valve surgery, 6.5% combined surgery, 3% aortic valve surgery, and 2.24% coronary surgery. Most cases of stroke (44%) were due to embolism, followed by hypoperfusion (25%). Stroke occurred within 2 days of surgery in 69% of cases. The mean NIHSS score in our sample of stroke patients was 9; code stroke was activated in 10 cases (62%); one patient (14%) underwent thrombectomy. Most patients progressed favourably: 13 (80%) scored≤2 on the modified Rankin Scale at 3 months. None of the patients died during the postoperative hospital stay.

CONCLUSION

In our setting, strokes occurring after cardiac surgery are usually small and have a good long-term prognosis. Most of them occur within 2 days, and they are mostly embolic in origin. The incidence of stroke in patients aged 80 and older and undergoing cardiac surgery is twice as high as that of the general population.

Intraoperative epiaortic scanning for preventing early stroke after off-pump coronary artery bypass

BACKGROUND

Numerous studies have demonstrated the accuracy of epiaortic ultrasound scanning (EAS) for assessing ascending aortic disease. It remains unclear whether EAS changes the incidence of perioperative stroke after off-pump coronary artery bypass (OPCAB).

METHODS

We studied a retrospective cohort of 2292 patients who underwent isolated OPCAB from January 2001 to December 2011. Patients were retrospectively subdivided into two groups: the non-EAS group (n=1019) who underwent OPCAB under only intraoperative transoesophageal echocardiography and the EAS group (n=1273) who underwent OPCAB under EAS.

RESULTS

In the non-EAS group, 317 (31.1%) patients underwent OPCAB with partial aortic clamping and 702 (68.9%) underwent OPCAB without partial aorta clamping. In the EAS group, 301 (23.7%) patients underwent OPCAB with partial aortic clamping and 972 (76.3%) underwent OPCAB without partial aortic clamping. The incidence of early stroke was not different statistically between the EAS and non-EAS groups [non-EAS 1.7% (17/1019) vs EAS 0.8% (10/1273); P=0.052]. However, in the subgroups of patients with partial aorta clamping, the incidence of the early stroke was significantly lower in the EAS group [2.8% (9/317) vs 0.7% (2/301) P=0.041].

CONCLUSIONS

EAS has a significant clinical benefit in reducing the incidence of early stroke in cases of partial aortic clamping in OPCAB. Therefore, EAS should be considered in patients who need partial aortic clamping in OPCAB.

Stroke after cardiac surgery--hemispheric distribution and survival

OBJECTIVES

Stroke following cardiac surgery may occur either in association with surgery (early) or occur postoperatively (delayed). The hemispheric distribution of lesions may provide information about embolic routes, which was analyzed here.

DESIGN

In 10,809 patients undergoing cardiac surgery, early (n = 223) and delayed stroke (n = 116) were explored. Symptoms and computed tomography findings were evaluated to categorize hemispheric distributions. This was compared with pre- and intra-operative characteristics and survival, using logistic regression and Kaplan-Meier statistics.

RESULTS

Early stroke had preponderance for the right rather than the left hemisphere (P = 0.009), whereas delayed stroke had a uniform distribution. Several intraoperative variables predicted the development of bilateral stroke compared with its unilateral counterpart. At multivariable analysis, the use of tranexamic acid was associated with bilateral stroke (P = 0.017), but was also associated with right rather than left-hemispheric stroke (P = 0.001). Bilateral lesions dramatically impaired survival versus those with unilateral lesions (P < 0.001). There was no survival difference between left and right-hemispheric stroke.

CONCLUSIONS

When stroke, after cardiac surgery, is subdivided into early and delayed forms, it becomes evident that early, but not delayed stroke, demonstrates a hemispheric side difference. The preponderance for right-hemispheric lesions may indicate embolic mechanisms routed via the brachiocephalic trunk.

Early and delayed stroke after coronary surgery - an analysis of risk factors and the impact on short- and long-term survival

OBJECTIVE

Stroke is a serious complication to cardiac surgery, and is generally considered as a uniform disease regardless of its temporal relationship to surgery. Our hypothesis suggests that stroke, in association with surgery, reflects other characteristics than stroke occurring with a free interval. This issue was here explored for risk factors and survival effects.

METHODS

Data were collected from 7839 procedures of isolated coronary artery bypass grafting (CABG), 297 off-pump CABG, and 986 combined CABG and valve procedures. Records of patients with any signs of neurological complications were reviewed to extract 149 subjects with stroke at extubation (early, 1.6%) versus 99 patients having a free interval (delayed, 1.1%). Survival data were complete, with a median follow-up time of 9.3 years (maximum 16.3 years). Independent risk factors were analyzed by logistic regression and survival by Cox regression.

RESULTS

Risk factors for early stroke were advanced age, high preoperative creatinine level, extent of aortic atherosclerosis, and long cardiopulmonary bypass time (all P<0.001). Factors associated with delayed stroke were female gender (P<0.001), unstable angina (P=0.003), previous cerebrovascular disease (P=0.009), inotropic support requirement (P<0.001), and postoperative atrial fibrillation (P<0.001). Stroke explained mortality not only in the early postoperative period (P<0.001), but also at long-term follow-up (P<0.001). Early and delayed stroke were associated with mortality hazard ratios (HRs) of 1.44 and 1.85 (P=0.008, P<0.001), respectively. However, for patients surviving their first postoperative year, early stroke did not influence long-term mortality (HR 1.07, P=0.695). This was in contrast to delayed stroke (HR 1.71, P=0.001).

CONCLUSIONS

Early and delayed stroke differed in their related risk factors. The influence of stroke on short-term mortality was obvious and devastating. Mortality in association with early stroke mainly presented itself in the acute period, whereas for delayed stroke survival continued to be impaired also in the long-term perspective. Our report emphasizes that early and delayed stroke should be considered as two separate entities.

Reducing emboli in cardiac surgery: does it make a difference?

Particulate embolization remains a serious complication of cardiac surgery. Adverse events associated with particulate embolization affect patient morbidity and long-term survival, and increase the length of hospital stay and the cost of health care. Today, atherosclerosis plays a role in at least two-thirds of all adverse events after coronary artery revascularization, and postoperative stroke is the second most common cause of operative mortality. Because many lower-risk patients now undergo interventional revascularization, higher-risk patients are now typically referred for surgical revascularization. These patients are older and sicker, and have multiple comorbidities, making them more susceptible to adverse events. For these high-risk patients, surgeons should be proactive in attempting to reduce the possibility of emboli. Patients must be carefully assessed before surgery to determine their risk, and if the risk is high, surgeons should consider using newer, innovative devices, and techniques in their operative strategy that have proven to be effective in mitigating some of the potential embolic adverse events. A multifaceted, preventive strategy can make a difference, not only in reducing particulate emboli, but also in reducing morbidity and in lowering the economic burden on the health-care system. This brief review will address three areas of focus that are important for the prevention of particulate embolization: (i) prevalence and morbidity of atherosclerotic disease; (ii) risk factors for adverse neurologic events; and (iii) prevention/mitigation of adverse events for patients undergoing cardiac surgery.

Technology insight: brain MRI and cardiac surgery--detection of postoperative brain ischemia

Annually, an estimated 1 million patients undergo heart surgery worldwide. Unfortunately, stroke continues to be a frequent complication of cardiac surgery, with the specific cerebrovascular risk depending upon the particular surgical procedure performed. Neuroimaging has an integral role in the initial evaluation and management of patients who present with acute stroke symptoms following cardiac surgery. The aim of this paper is to review the role brain MRI has in detecting postoperative brain ischemia in these patients. Multimodal MRI--using diffusion-weighted MRI (DWI), perfusion-weighted MRI, and gradient-recalled echo imaging--has an excellent capacity to identify and delineate the size and location of acute ischemic strokes as well as intracerebral hemorrhages. This differentiation is critical in making appropriate treatment decisions in the acute setting, such as determining patient eligibility for thrombolytic or hemodynamic therapies. At present, DWI offers prognostic value in patients with strokes following cardiac surgery. Additionally, DWI could be a valuable tool for evaluating stroke preventive measures as well as therapeutic interventions in patients undergoing CABG surgery.

Aortic plaque distribution in relation to cross clamp and cannulation procedures during cardiac surgery

OBJECTIVE

Aortic atherosclerosis may cause cerebrovascular accidents in cardiac surgery. Aortic plaque distribution was analyzed in relation to surgical manipulation.

DESIGN

In 24 autopsy subjects the thoracic aorta was digitally analyzed by macro-anatomic mapping of plaques. Plaque density was compared in different anatomical segments. Hazards associated with surgical manipulation were blindly studied by superimposing cannulation and cross-clamp locations onto the maps.

RESULTS

Plaques were frequent. The anterior wall of the ascending/arch aorta had higher plaque density than its posterior side (p=0.039). However, an anterior plaque predicted to 83% a concomitant plaque in the posterior wall. Plaque formation correlated with age (p=0.004). The theoretical risk of interfering with a plaque during cannulation and/or clamp positioning was 46%.

CONCLUSIONS

Plaque formation is a frequent and age-dependent problem. In the surgery-exposed aorta, the anterior wall had higher plaque density than the posterior side, although the two sides showed strong plaque coexistence. Furthermore, there was an unexpectedly high risk of plaque interference during cannulation and/or clamp maneuvers if blindly performed. The present results emphasize the importance of epiaortic scanning.

Intraluminal aortic manipulation by means of intra-aortic filter, cannulation, and external clamp maneuvers evaluated versus dislodged embolic material

OBJECTIVES

Aortic atherosclerosis is an important risk factor for cerebrovascular accidents in cardiac surgery. An intra-aortic filter might reduce this risk. We aimed to analyze the risks for emboli associated with intraluminal aortic manipulation and intra-aortic filter handling in relation to cannulation and external clamp maneuvers.

METHODS

A model was designed with a cadaver aorta and retrograde perfusion (n = 16). A crossclamp was positioned on the ascending aorta and repeatedly opened under pressure to collect aliquots with dislodged particles. Cannulation was performed after 10 clamp maneuvers, followed by positioning and removing the intra-aortic filter, with each step followed by a washout sequence to collect perfusate. The removed filter was also analyzed. Evaluation was by means of digital image analysis, with differentiation of particles into different spectra.

RESULTS

Intra-aortic filter manipulation produced a significant washout of embolic particles; in particular, this was seen for the macroscopic cellular spectrum (P = .006 and P = .002 for filter insertion and removal, respectively). Particles were also found to be collected by the filter (P = .004). In addition, cannulation and aortic crossclamp manipulation generated a notable number of particles (P = .001 and P = .013, respectively).

CONCLUSIONS

The intra-aortic filter collects material during aortic manipulation. However, intraluminal aortic manipulation from filter handling can also dislodge particles, possibly related to shedding of intimal debris. This is in addition to substantial amounts of particles that are generated by aortic cannulation and aortic crossclamping.

Cerebrovascular accidents after cardiac surgery: an analysis of CT scans in relation to clinical symptoms

There is a link between aortic manipulation, particle embolization, and cerebrovascular accidents (CVA) in cardiac surgery. The present aim was to study hemispheric side differences of CVA. Cardiac-surgery patients with CVA and with computer tomography (CT) performed (n = 77) were analyzed within a total group of 2641 consecutive cases. CT data were reviewed for hemispheric and vascular distribution, and compared with CVA-symptom data of immediate and delayed type. Of the included patients, 66% had positive CT. In the group of 'cardiac-type' operations (e.g., routine clamping and cannulation) and having immediate CVA, right-hemispheric lesions were more frequent than of the contra-lateral side (p = 0.005). Patients with aortic dissections had strong dominance of bilateral findings, which was different from the unilateral pattern of 'cardiac-type' operations (p = 0.001). The middle-cerebral artery territory dominated, and when involved showed a significant (p = 0.022) right-sided distribution. Both CT and clinical symptoms confirmed that CVA after cardiac surgery has a right-hemispheric predominance. These observations may imply that aortic manipulation directs embolic material towards the brachiocephalic trunk.