Atherosclerosis of the ascending aorta is an independent predictor of long-term neurologic events and mortality

[Isolated coronary surgery in the octogenarian. Immediate results and analysis of long-term survival rate and quality of life]

BACKGROUND

There are almost three million octogenarians living in France, many of whom present with a coronaropathy. Moreover, it appears that life expectancy at 80 years of age is still important.

OBJECTIVE

To evaluate the results of coronary surgery among these patients.

METHODS

Eighty-eight consecutive octogenarians who had an isolated coronary artery bypass surgery between 1996 and 2002 were compared with 165 patients 60 to 70 years of age; the two groups had been paired according to the main risk factors. Patients were contacted by telephone and then received a quality-of-life-related questionnaire.

RESULTS

Operative mortality was 2.3% in the octogenarian versus 1.2% in the 60- to 70-year-old group (P not significant). There was more low cardiac output syndrome, postoperative acute renal failure and transfusion in octogenarians. Long-term survival (average duration of follow-up was 3.8 years) was higher in the 60- to 70-year-old group: 89.7% versus 77.9% (P=0.025). Four independent risk factors of long-term increased mortality were found: age, diabetes, history of stroke and postoperative blood transfusion. Finally, the long-term survival in the octogenarians who had this surgery was higher than in the octogenarians of the general French population to a significant degree, with a quality of life considered to be satisfactory.

CONCLUSION

For selected octogenarians, an isolated coronary surgery can be proposed, with short- and long-term results comparable with those of a younger population.

Risk factors for neurocognitive dysfunction after cardiac surgery in postmenopausal women

BACKGROUND

Women are at higher risk than men for neurologic complications from cardiac operations. This study identified risk factors for neurocognitive dysfunction after cardiac operations in elderly women.

METHODS

One hundred thirteen postmenopausal women undergoing primary coronary artery bypass grafting, with or without valve operation, underwent psychometric testing and neurologic evaluation the day before operation and 4 to 6 weeks postoperatively. Risk factors assessed for neurologic complications included atherosclerosis of the ascending aorta and apolipoprotein epsilon4 genotype. Postoperative neurocognitive dysfunction was defined as the composite end point of a one standard deviation decrement from baseline on two or more psychometric tests or a new neurologic deficit.

RESULTS

Neurocognitive dysfunction was present in 25% of the women 4 to 6 weeks postoperatively. Women with a neurocognitive deficit tended to be older than those without a deficit (72.1 +/- 8.1 vs 69.4 +/- 8.9 years, p = 0.144) and were more likely to have mild atherosclerosis of the ascending aorta, a history of congestive heart failure, longer duration of cardiopulmonary bypass (CPB) and aortic cross-clamping, lower nadir blood pressure during CPB, higher rates of postoperative atrial fibrillation, and longer postoperative hospitalization. Mild atherosclerosis of the ascending aorta, duration of CPB, duration of aortic cross-clamping (p = 0.051), and length of postsurgical hospitalization were independently associated with postoperative neurocognitive dysfunction.

CONCLUSIONS

Mild atherosclerosis of the ascending aorta, duration of CPB, aortic cross-clamping time, and length of hospitalization, but not apolipoprotein epsilon4 genotype, identified risk for neurocognitive dysfunction after cardiac operation in postmenopausal women.

Brain protection in cardiac surgery

Brain injury is a major source of patient morbidity after cardiac surgery, and is associated with prolonged hospitalization, excessive operative mortality, high hospital costs, and altered quality of life. Frequency and the clinical manifestations depend on multiple factors, including the completeness and timing of neurologic testing. Ischemic brain infarctions may or may not be associated with stroke or postoperative neurocognitive dysfunction, but the long-term implications of these lesions on neurologic function have not yet been extensively evaluated. This article reviews the current views on the pathophysiologic basis of cerebral injury after cardiac surgery and provides a summary of measures aimed at reducing its occurrence.

Cardiac anesthesia and surgery in geriatric patients

The average age of US population is steadily increasing, with more than 15 million people aged 80 and older. Coronary artery disease and degenerative cardiovascular diseases are particularly prevalent in this population. Consequently, an increasing number of elderly patients are referred for surgical intervention. Advanced age is associated with decreased physiologic reserve and significant comorbidity. Thorough preoperative assessment, identification of the risk factors for perioperative morbidity and mortality, and optimal preparation are critical in these patients. Age-related changes in comorbidities and altered pharmacokinetics and pharmacodynamics impacts anesthetic management, perioperative monitoring, postoperative care, and outcome. This article updates the age-related changes in organ subsystems relevant to cardiac anesthesia, perioperative issues, and intraoperative management. Early and late operative outcome in octogenarians undergoing cardiac surgery are reviewed. The data clearly indicate that no patient group is "too old" for cardiac surgery and that excellent outcomes can be achieved in selected group of elderly patients.

Mechanisms of cerebral injury from cardiac surgery

Cerebral injury is a frequent complication of cardiac surgery, and it has been associated with high mortality, morbidity, hospital costs; an increased likelihood of admission to a secondary care facility after hospital discharge; and impaired quality of life. This article examines postulated mechanisms for cerebral injury from cardiac surgery. Most emphasis has been placed in the past on the intraoperative interval as being the period of highest cerebral vulnerability. Many clinical cerebral events, however, occur in the postoperative period.

The influence of epiaortic ultrasonography on intraoperative surgical management in 6051 cardiac surgical patients

BACKGROUND

Intraoperative echocardiography has become a mainstay monitor of cardiac function and a popular diagnostic tool in patients undergoing cardiac procedures. Previous reports suggest that epiaortic ultrasonography (EU) is superior to transesophageal echocardiography and manual palpation in identifying ascending aortic atheroma. Its impact on surgical decision making has not been thoroughly investigated, however.

METHODS

We retrospectively analyzed the medical records of 6051 consecutive patients who underwent EU of their ascending aorta during cardiac operations between 1996 and 2006 to determine a potential impact on intraoperative surgical decision making. Aortic atheroma was graded according to standard classification. Neurologic complications were evaluated according to the Society of Thoracic Surgeon definition for stroke and transient ischemic attack (TIA).

RESULTS

The overall impact of EU on surgical decision making was 4.1% and included a change in the technique for inducing cardiac arrest in 1.8%, aortic atherectomy or replacement surgery in 0.8%, requirement for off-pump coronary artery bypass grafting (CABG) in 0.6%, avoidance of aortic cross-clamping and use of ventricular fibrillatory arrest in 0.5%, change in arterial cannulation site in 0.2%, or avoidance of aortic cannulation in 0.2%. The greatest affect of EU was observed in patients undergoing combined CABG with aortic/mitral valve procedures (6.7%). The smallest impact was seen in patients undergoing mitral valve operations (1.4%). Aortic atheroma was more frequent on the anterior aspect of the aorta (n = 171) in patients with a change in surgical plan than on the posterior aspect (n = 78). The overall stroke rate was lower in patients with intraoperative EU compared with all patients undergoing surgical procedures.

CONCLUSIONS

Epiaortic ultrasonography is a useful technique to detect ascending aortic atheroma, has a significant impact on surgical decision making in more than 4% of cardiac surgical patients, and might result in improved perioperative neurologic outcome.

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.

Patch aortoplasty for proximal anastomosis of coronary artery bypass grafts in patients with complex aortic pathology

Proximal anastomosis of conduits to the ascending aorta in patients undergoing coronary artery bypass grafting may be hazardous or impossible in the presence of complex aortic pathology. We describe a technique of the excision of a segment of the diseased aortic wall, reconstruction with a bovine pericardial patch, and attachment of the grafts to the patch. The technique was used successfully in 2 patients (ie, 1 patient with Takayasu's disease and the other with a heavily calcified aorta).

Cerebral dysfunction after cardiac surgery--are we moving forward?

This review focuses on the effects of cardiac surgery and cardiopulmonary bypass on the brain, with special emphasis on the results of recently conducted studies. The incidence of postoperative neurological and neuropsychological deficits and risk factors for cerebral injury are reviewed. The relationships between cerebral embolic load, release of biochemical markers of brain injury and cognitive dysfunction after cardiac surgery are also reviewed. Finally, recently gained information on the management of cardiopulmonary bypass is discussed, along with the results of recent pharmacological neuroprotective trials in patients undergoing cardiac surgery.

The topography of aortic atherosclerosis enhances its precision as a predictor of stroke

BACKGROUND

Atherosclerosis of the thoracic aorta is an independent risk factor for stroke after cardiac surgery. No attention had so far been paid to its topography. The relationship between the topography of aortic atherosclerosis and stroke was studied in patients admitted for coronary surgery.

METHODS

The extent and location of atherosclerosis in the ascending aorta and arch was assessed intraoperatively with epiaortic ultrasound and transesophageal echocardiography in 611 consecutive patients. They were followed for 5.5 +/- 1.7 years (mean +/- SE), amounting to 3,358 patient-years.

RESULTS

The incidence of early postoperative (<30-day) stroke was 6.4% in patients with atherosclerosis of the ascending aorta and 1.5% in those without (p = 0.004). The five-year stroke-free survival rates (>30 days after the operation) for patients without aortic disease, with less than 50%, and with greater than 50% of the ascending aorta affected, were 95.3 +/- 0.9%, 91.8 +/- 2.1%, and 65.0 +/- 14.6%, respectively (p < 0.0001).

CONCLUSIONS

Atherosclerosis of the ascending aorta stands out as a predictor of late stroke. High risk is predominantly linked to atheromas in its distal part and lesser curvature.

The impact of increasing age on anatomic factors affecting carotid angioplasty and stenting

PURPOSE

Current evaluations of carotid artery angioplasty and stenting (CAS) have suggested equivalency compared with carotid endarterectomy (CEA). However, the incidence of stroke and death with CAS may be higher in elderly patients. We assessed the anatomic characteristics of patients undergoing CAS and compared them based on age older or younger than 80 years. The impact of age on the incidence of postoperative complications was also determined.

METHODS

From February 2003 to August 2005, 135 CAS procedures were performed in 133 patients. Digital subtraction angiograms for each patient were evaluated by two independent observers blinded to patient identifiers. Anatomic characteristics that impact the performance of CAS were assessed as either favorable or unfavorable. These included aortic arch elongation, arch calcification, arch vessel origin stenosis, common and internal carotid artery tortuosity, and treated lesion stenosis, calcification, and length. Postoperative events were defined as myocardial infarction, stroke, and death. Fisher's exact test and chi(2) tests were used to determine statistical significance (P < .05).

RESULTS

Of the 133 patients treated, 87 (65%) were men and 46 (35%) were women; and 37 (28%) were >or=80 years of age. The cohort >or=80 years old had an increased incidence of unfavorable arch elongation (P = .008), arch calcification (P = .003), common carotid or innominate artery origin stenosis (P = .006), common carotid artery tortuosity (P = .0009), internal carotid artery tortuosity (P = .019), and treated lesion stenosis (P = .007). No significant difference was found for treated lesion calcification or length. Perioperative cerebral vascular accidents occurred in four patients (3.0%, 3 with no residual deficit, 1 with residual deficit), myocardial infarction in three (2.2%), and one patient (0.8%) died secondary to a hemorrhagic stroke. The combined stroke, myocardial infarction, and death rate for the entire population was 3.7%. The rate was significantly increased in patients aged >or=80 years old (10.8%) compared with those aged <80 years old (1%, P = .012).

CONCLUSIONS

Elderly patients, defined as those aged >80 years, have a higher incidence of anatomy that increases the technical difficulty of performing CAS. This increase in unfavorable anatomy may be associated with complications during CAS. Although the small number of perioperative events does not allow for determination of a direct relationship with specific anatomic characteristics, the presence of unfavorable anatomy does warrant serious consideration during evaluation for CAS in elderly patients.

Apicoaortic valved conduit: Potential for progress?

OBJECTIVE

The number of elderly patients who require aortic valve replacement is growing, as is the increase of complicating factors, such as previous coronary bypass grafting and atherosclerotic disease of the ascending aorta. An uncommon surgical option to aortic valve replacement is the apicoaortic valved conduit. In this article the techniques and outcomes of 13 cases of apicoaortic valved conduit insertions in high-risk patients are described.

METHODS

From 2002 through 2005, 13 patients (mean age, 75 +/- 8.7 years; 8 men) with severe calcific aortic stenosis had insertions of an apicoaortic valved conduit because of a porcelain aorta (n = 4), previous coronary bypass grafting (n = 6), or both (n = 3). The off-pump technique was used in 9 patients, and a heparinized miniextracorporeal circulation system was used in 4 patients. Follow-up time was 6 to 33 months.

RESULTS

Mean intensive care stay was 2 +/- 2.7 days, and mean hospital stay was 12 +/- 8 days. The 30-day mortality was 15% (2 patients; postoperative days 3 and 28, both caused by myocardial infarction). Mortality later than 30 days postoperatively was 23% (3 patients; postoperative day 45 caused by bilateral pulmonary bleeding because of pneumonia, postoperative day 56 caused by myocardial infarction, and postoperative day 81 caused by pneumonia). The remaining 8 patients were doing well, all in New York Heart Association class I or II at follow-up, with echocardiography showing a low gradient over the valved conduit.

CONCLUSIONS

The apicoaortic valved conduit in high-risk patients undergoing aortic valve replacement remains a feasible option, with a substantial potential for technical development and progress.

Carotid sonography and transesophageal echocardiography in patients with ischemic stroke or transient ischemic attack in the territory of the carotid artery

PURPOSE

To assess the benefit of combining carotid sonography and transesophageal echocardiography (TEE) for the evaluation of patients with stroke or transient ischemic attack (TIA) in the territory of the carotid artery.

METHODS

During a 2-year period in Turku University Hospital, consecutive in patients with stroke or TIA who were candidates for carotid endarterectomy and for oral anticoagulation were evaluated with carotid sonography for symptomatic moderate (50-69%) or severe (>or=70%) internal carotid artery (ICA) stenosis, and with TEE for potential cardiac sources of embolism.

RESULTS

In 20% (40/197) of patients, a severe symptomatic ICA stenosis and/or a major risk factor for a cardiac source of embolism were found. In 56% (110/197) of patients, a moderate or severe symptomatic ICA stenosis and/or a potential cardiac source of embolism were found, whereas 11% (21/197) of patients had both a moderate or severe symptomatic ICA stenosis and a potential cardiac source of embolism.

CONCLUSIONS

This study suggests that the presence of a moderate or severe symptomatic ICA stenosis does not exclude the presence of a potential cardiac source of embolism and vice versa. Carotid sonography and TEE complement each other and are valuable diagnostic tools that should be recommended in patients with ischemic stroke or TIA in the territory of the carotid artery when they are candidates for carotid endarterectomy and for oral anticoagulation.

Aortic arch atheroma and the risk of stroke

Brain infarction of unknown cause, known as cryptogenic stroke, represents 30% to 40% of all ischemic strokes, or approximately 400,000 cases each year in western Europe. In this category of patients new potential causes, such as aortic arch atheroma in the elderly, have been investigated in the past two decades.

Surgical Approach in Massive Intraoperative Atherosclerotic Embolism

We describe a case of massive embolization of atherosclerotic material during aortic cannulation and the surgical approach chosen to treat it, that is, retrograde cerebral perfusion and subtotal arch replacement in deep hypothermic circulatory arrest.

Primary Prevention of Ischemic Stroke

Background and Purpose— This guideline provides an overview of the evidence on various established and potential stroke risk factors and provides recommendations for the reduction of stroke risk.

Methods— Writing group members were nominated by the committee chair on the basis of each writer’s previous work in relevant topic areas and were approved by the American Heart Association Stroke Council’s Scientific Statement Oversight Committee. The writers used systematic literature reviews (covering the time period since the last review published in 2001 up to January 2005), reference to previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and when appropriate, formulate recommendations based on standard American Heart Association criteria. All members of the writing group had numerous opportunities to comment in writing on the recommendations and approved the final version of this document. The guideline underwent extensive peer review before consideration and approval by the AHA Science Advisory and Coordinating Committee.

Results— Schemes for assessing a person’s risk of a first stroke were evaluated. Risk factors or risk markers for a first stroke were classified according to their potential for modification (nonmodifiable, modifiable, or potentially modifiable) and strength of evidence (well documented or less well documented). Nonmodifiable risk factors include age, sex, low birth weight, race/ethnicity, and genetic factors. Well-documented and modifiable risk factors include hypertension, exposure to cigarette smoke, diabetes, atrial fibrillation and certain other cardiac conditions, dyslipidemia, carotid artery stenosis, sickle cell disease, postmenopausal hormone therapy, poor diet, physical inactivity, and obesity and body fat distribution. Less well-documented or potentially modifiable risk factors include the metabolic syndrome, alcohol abuse, drug abuse, oral contraceptive use, sleep-disordered breathing, migraine headache, hyperhomocysteinemia, elevated lipoprotein(a), elevated lipoprotein-associated phospholipase, hypercoagulability, inflammation, and infection. Data on the use of aspirin for primary stroke prevention are reviewed.

Conclusion— Extensive evidence is available identifying a variety of specific factors that increase the risk of a first stroke and providing strategies for reducing that risk.

Extra-aortic balloon counterpulsation: an intraoperative feasibility study

BACKGROUND

Current methods of counterpulsation or ventricular assistance have significant vascular and limb complications. The aim of this study was to determine the safety and performance of a new method of non-blood-contacting counterpulsation using an inflatable cuff around the ascending aorta (extra-aortic balloon [EAB]).

METHODS AND RESULTS

In 6 patients undergoing first time off-pump coronary bypass surgery via sternotomy, the EAB was secured around the ascending aorta and attached to a standard counterpulsation console. At baseline and with 1:2 and 1:1 augmentation, hemodynamic and echocardiographic parameters of ventricular function and coronary flow were measured. High-intensity transient signals were measured using transcutaneous Doppler over the right common carotid artery. No complications occurred. With EAB there was no significant change in heart rate or blood pressure and no increase in high-intensity transient signals. There was a 67% increase in diastolic coronary blood flow (mean left-main diastolic velocity time integral 15.3 cm unassisted versus 25.1 cm assisted, P<0.05). Measurements with transesophageal echocardiography at baseline and with 1:1 counterpulsation demonstrated a 6% reduction in end-diastolic area (P=NS), a 16% reduction in end-systolic area (P<0.01), a 31% reduction in left ventricular wall stress (P<0.05), and a 13% improvement in fractional area change (P<0.005).

CONCLUSIONS

EAB counterpulsation augments coronary flow and reduces left ventricular afterload. Further testing is warranted to assess the use of the EAB for chronic non-blood-contacting support of the failing heart.

Stroke and Encephalopathy After Cardiac Surgery

Background and Purpose— As a result of advances in surgical, anesthetic, and medical management, cardiac surgery can now be performed on older, sicker patients, some of whom have had prior cardiac interventions. As surgical mortality has declined in recent years, attention has focused on the complications of stroke and encephalopathy after cardiac surgery.

Summary of Review— Patients with preexisting cerebrovascular disease are at increased risk for these untoward neurological outcomes, which are associated with longer lengths of hospital stay, higher costs, and greater mortality. The mechanisms underlying these neurological events may include microemboli and hypoperfusion during surgery, and postoperative atrial fibrillation. Predictive models, based on information available before surgery, allow identification of these “high risk” patients.

Conclusion— Establishing the degree of functionally significant vascular disease of the brain before surgery should be an essential part of the preoperative evaluation, particularly when modifications in surgical technique or novel neuroprotective agents are being evaluated.

Analysis of anatomic factors and age in patients undergoing carotid angioplasty and stenting

Recent data suggest that patient age >80 years may be associated with increased risk of periprocedural complications from carotid angioplasty and stenting (CAS). In this study, we analyzed anatomic risk factors in patients undergoing CAS based on age >80 or <80 years. Our hypothesis was that patients >80 would have more challenging anatomy. Between February 2003 and August 2004, 82 patients underwent CAS. Images for 57 lesions were available for review. Eighteen patients were > or =80 years old and 39 were <80. Cerebral protection devices, including EPI Filterwire, Percusurge, Accunet, and Angioguard, were used in all but two cases; and self-expanding stents (Wallstent, NexStent, Acculink, Precise) were placed in all. Arterial anatomic characteristics were assigned a score based on complexity and associated procedural risk. Characteristics evaluated using angiographic images were aortic arch elongation classification, arch calcification, common carotid/innominate stenosis, common carotid tortuosity, internal carotid tortuosity, index lesion length, index lesion calcification, and index lesion stenosis. Statistical analysis was performed using Fisher's exact test. CAS was successfully completed in 98% of cases. The two patients in whom we could not perform CAS were 79 and 83 years old. The anatomic characteristics that were statistically significantly more complex/severe in patients > or =80 were arch calcification (p = 0.045), common carotid/innominate stenosis (p = 0.023), common carotid tortuosity (p = 0.049), and internal carotid tortuosity (p = 0.032). There was no statistically significant difference in arch elongation classification, lesion length, lesion calcification, or stenosis severity (p = nonsignificant). Overall, patients > or =80 years had an increased incidence of complex anatomic risk factors compared to younger patients (p < 0.001). Cerebrovascular accident without residual deficits occurred in two patients; both were >80 years old. Complex arterial anatomy is more often present in patients >80 years and may explain the increased complication rates associated with CAS. Pre- or intraoperative consideration of these characteristics may help provide better risk assessment in candidates for CAS.

Do stroke patients with normal carotid arteries require TEE for exclusion of relevant aortic plaques?

OBJECTIVES

This study investigated (a) the hypothesis that stroke patients with aortic atheroma would show comparable atherosclerotic changes in the carotid arteries, which are easily accessible for ultrasound evaluation and (b) the possibility of carotid duplex sonography as a replacement for transoesophageal echocardiography (TEE) for the exclusion or prediction of relevant aortic plaques.

METHODS

In 301 consecutive patients (mean age 62 years) with acute cerebral ischaemia, two dimensional ultrasound measurements were taken of common carotid artery intima media thickness (IMT) and maximal plaque area (PA) and the local degree of internal carotid artery (ICA) stenosis were determined. Maximal aortic wall thickness (AWT) was assessed by TEE.

RESULTS

An IMT < or =0.9 mm yielded a negative predictive value (NPV) of 95.8% for exclusion of aortic atheromas > or =4 mm and an NPV of 100% for the exclusion of aortic thrombi. However, positive predictive value of IMT >0.9 mm was low (29.6%), increasing only slightly in the presence of carotid plaques (33%). Incidence of aortic thrombi was significantly higher with > or =50% compared with <50% ICA stenosis (11.3% v 3.9%, respectively). IMT and PA correlated moderately with AWT (r = 0.47, r = 0.53, respectively; p<0.001). Systolic blood pressure, coronary heart disease and peripheral artery disease, increased IMT, and ICA stenosis > or =50% were independently related to AWT > or =4 mm.

CONCLUSIONS

A high NPV of normal carotid ultrasound does not support routine TEE for the exclusion of complex aortic plaques as a high risk source of cerebral embolism. However, in patients with carotid atherosclerosis, particularly in those with ICA stenosis > or =50%, TEE should be performed to exclude an additional high risk source for stroke.

Improved Visualization of Aortic Intima-media Thickening with the Use of Perflutren Lipid Microspheres

BACKGROUND

Transesophageal echocardiography (TEE) has been used to diagnose atherosclerotic disease for patients who present with systemic embolic events. The primary aim of this study was to assess the supplemental value of echocardiographic contrast to standard TEE in identifying the aortic intima-medial thickness.

METHODS

An aorta phantom was used to validate the accuracy of border delineation with and without contrast during TEE imaging. In all, 44 patients underwent TEE imaging of the thoracic aorta with a subsequent administration of a 0.3-mL bolus of perflutren lipid microspheres (Definity). Precontrast and postcontrast images were analyzed semiquantitatively for border delineation and quantitatively for intima-medial thickness and cross-sectional area.

RESULTS

Wall thickness in the aortic phantom model with contrast was smaller, more accurate, and more reproducible to the true measurement. The clinical studies reflected similar results with average contrast intima-medial thickness measured at 0.15 +/- 0.08 cm and noncontrast at 0.18 +/- 0.08 cm (P < .01). The lateral wall showed the greatest improvement with a score of 1.23 increasing to an average of 1.82 (P < .001) with contrast. The medial, anterior, and posterior walls improved to an average 1.98, 1.39, and 2.0, respectively (P = .01).

CONCLUSIONS

Contrast agents provide better aortic intima-media enhancement during TEE.

Low Hematocrit During Cardiopulmonary Bypass is Associated With Increased Risk of Perioperative Stroke in Cardiac Surgery

BACKGROUND

The relationship between degree of hemodilution during cardiopulmonary bypass (CPB) and perioperative stroke has not been fully elucidated. The objective of this observational study was to evaluate the relationship between nadir hematocrit during CPB and perioperative stroke while adjusting for variables known to have an association with stroke and anemia.

METHODS

Perioperative data were prospectively collected on 10,949 consecutive patients who underwent cardiac surgery with CPB from 1999 to 2004 at a quaternary care hospital. Stroke was defined as a persistent neurologic deficit, consistent with a central nervous system lesion, occurring within 30 days of operation. Stroke was classified as perioperative if patients awoke from anesthesia with neurologic symptoms and postoperative if patients awoke without symptoms. Multivariable logistic regression analysis was used to control for confounding variables to obtain the independent relationship between nadir hematocrit during CPB and perioperative stroke.

RESULTS

The prevalence of perioperative stroke was 1.0% (n = 110). An additional 50 patients had postoperative stroke. Nadir hematocrit during CPB was an independent predictor of perioperative stroke. After controlling for confounding variables, each percent decrease in hematocrit was associated with a 10% increase in the odds of suffering perioperative stroke (95% confidence interval, 4% to 18%; p = 0.002). The model was accurate (c-index = 0.85) and reliable (Hosmer-Lemeshow test p = 0.4).

CONCLUSIONS

There is an independent, direct association between degree of hemodilution during CPB and risk of perioperative stroke. Prospective randomized clinical trials comparing different degrees of hemodilution during CPB are required to determine whether this is a cause-effect relationship or a simple association.

Extra-Ascending Aortic Versus Intra-Descending Aortic Balloon Counterpulsation—Effect on Coronary Artery Blood Flow

BACKGROUND

Diastolic counterpulsation has been used to provide circulatory augmentation for chronic heart failure or for short-term cardiac support. Recently an extra-aortic balloon (EAB) counterpulsation device has been proposed.

AIM

To compare the circulatory effects of counterpulsation using the EAB or an intra-aortic balloon (IAB) in the acute pig model.

METHODS

In six anaesthetized great white pigs (paced at 100 bpm), ECG, arterial and central venous pressures, flow in the coronary circulation and descending thoracic aorta were measured. Baseline data was collected, then with the EAB or an IAB fitted using 1:1 and 1:2 counterpulsation modes. Baseline data was compared to EAB and IAB data in 1:1 mode. Assisted beat data compared to unassisted beat data was also analysed in 1:2 mode.

RESULTS

Both devices augmented peak diastolic arterial pressure, and decreased afterload. EAB counterpulsation increased diastolic coronary flow in both the 1:1 mode by 69% (p < 0.05) and in the 1:2 mode by 63% (assisted versus unassisted beat, p < 0.05). The IAB significantly increased diastolic coronary flow only in the 1:2 mode by 28% (p < 0.01). Both devices augmented total coronary flow and some augmentation of aortic flow was observed.

CONCLUSION

The circulatory effect of the EAB and IAB counterpulsation were comparable. This suggests the EAB could be used as a non-blood contacting heart assist device in patients suffering moderate-severe heart failure.

L’apport de l’échocardiographie transœsophagienne au diagnostic des lésions emboligènes de l’aorte thoracique

Atherosclerotic plaques of the thoracic aorta are a well-recognized source of systemic embolism, especially cerebral embolism, in patients 60 years of age or older. The most helpful and readily available imaging technique to detect aortic plaques is transesophageal echocardiogram. Aortic plaques>4mm in thickness are the more likely to cause peripheral embolism. Moreover, plaque morphology is important to consider, since ulcerated plaques and plaques with mobile intra-aortic components ("debris") as well as hypoechoic and noncalcified plaques are at the higher risk of embolism. In addition to these common atherosclerotic lesions, rare cases of mobile thromboses of the aortic arch without aortic debris have been described in younger patients. Finally, a particular situation is that of cholesterol embolism following invasive intra-aortic maneuvers on atherosclerotic aortas. While the diagnosis of these lesions is well established, their management and treatment remain controversial.

Risk factors for late stroke after coronary artery bypass grafting

BACKGROUND

Postoperative stroke is a severe complication immediately after coronary artery bypass grafting, and it significantly deteriorates the postoperative quality of life if it occurs in the long term. It was the aim of our study to determine factors associated with the occurrence of new strokes during long-term follow-up after coronary artery bypass grafting.

METHODS

From 387 of 500 patients undergoing coronary artery bypass grafting (age, 67 years [33-84 years]; 76% male) who had intraoperative epiaortic ultrasonography for assessment of ascending aortic wall thickness, a complete follow-up regarding postoperative stroke was achieved. The median follow-up time was 52 months (9-74 months).

RESULTS

A stroke occurred in 26 (7%) of 387 patients, and the cumulative freedom from stroke was 99%, 95%, and 89% after 1, 3, and 5 years, respectively. A significantly lower freedom from stroke was present in patients with an age of 70 years or more (P = .007), preoperative unstable angina (P = .031), chronic obstructive pulmonary disease (P = .009), carotid artery disease (P < .001), preoperative history of neurologic events (P < .001), and a maximum ascending aortic wall thickness of 4 mm or more (P = .010). Multivariate analysis revealed preoperative history of neurologic events (P = .021) to be an independent risk factor.

CONCLUSION

Patients with ascending aortic atherosclerosis, older age (> or =70 years), preoperative unstable angina, chronic obstructive pulmonary disease, and carotid artery disease are at risk for late postoperative stroke after coronary artery bypass grafting. A history of neurologic events is of special predictive importance.

Atherosclerosis of the ascending aorta as a major determinant of the outcome of cardiac surgery

Epiaortic ultrasonography has high sensitivity for the detection of atherosclerosis. In several studies, the technique has identified atherosclerosis of the ascending aorta as the major risk factor for stroke after cardiac surgery. The level of risk depends on the presence, location and extent of disease when the ascending aorta is surgically manipulated. This knowledge enables clinicians to focus on the diagnostic and surgical technique and to consider the various options. Routine use of intraoperative epiaortic ultrasonography should be applied so that surgical manipulation of the ascending aorta can be reduced or, if possible, avoided in patients with atherosclerosis of the ascending aorta. Alternatively, if major manipulation such as clamping must be performed in the presence of severe atherosclerosis, the use of intra-aortic filters could be considered.

Fluvastatin reduces the 4-year cardiac risk in patients with multivessel disease

BACKGROUND

To evaluate the impact of the extent of coronary disease (single- or multivessel) and of fluvastatin treatment on the incidence of long-term cardiac atherosclerotic complications in the Lescol Intervention Prevention Study (LIPS).

METHODS

A total of 1063 patients with single-vessel disease and 614 patients with multivessel disease were randomized to receive fluvastatin (40 mg bid) or placebo for at least 3 years following a first successful percutaneous coronary intervention. The incidence of cardiac atherosclerotic events (cardiac death, non-fatal myocardial infarction, and coronary re-interventions not related to restenosis) was evaluated.

RESULTS

Patients with multivessel disease tended to be older and presented a higher prevalence of associated risk factors and cardiovascular antecedents. The presence of multivessel disease markedly increased the risk of cardiac atherosclerotic events compared with single-vessel disease among patients allocated to placebo (RR 1.67 [95% CI: 1.24-2.25]; p<0.001). In patients treated with fluvastatin, however, no significant differences in long-term outcomes were observed between patients with multivessel disease and patients single-vessel disease (RR 1.28 [95% CI: 0.90-1.81]; p=0.2).

CONCLUSIONS

Multivessel coronary disease impaired the 4-year outcomes after percutaneous intervention. However, the hazardous effect of multivessel disease was significantly reduced by long-term fluvastatin treatment.

The risk of stroke following CABG: one possible strategy to reduce it?

OBJECTIVE

Stroke remains a devastating complication of coronary artery bypass grafting (CABG): we evaluated whether a more aggressive diagnostic and therapeutic approach can reduce its incidence.

METHODS

Between January 1998 and January 2002, 1388 consecutive patients underwent isolated on pump CABG with blood cardioplegia. Among the first 627 patients (Group A), Echo-Doppler study (DS) was performed only in selected patients (58) with history of cerebrovascular disease (CVD) and/or carotid bruit; in 761 patients (Group B), DS was performed routinely. Carotid endarterectomy (CEA) was performed in 45 patients in Group A associated to CABG during cardiopulmonary bypass (CPB) and in 90 patients in Group B under local anaesthesia before CABG. Brain CT scan was performed in all cases with postoperative neurological symptoms.

RESULTS

The two groups were homogeneous for age, sex, associated diseases, history of CVD, number of graft and CPB time. There were no differences in terms of hospital mortality between Group A (22/627: 3.5%) and Group B (21/761: 2.75%); p=0.5. Postoperative stroke was observed in 24/627 (3.82%) patients of Group A and in 2/761 (0.26%) of Group B (p<0.001). Hospital mortality for stroke was higher in Group A (12/627: 1.91%) than in Group B (0/761; p<0.001) as well as the incidence of non-fatal stroke (Group A 12/627: 1.91% versus Group B 2/761: 0.26% p=0.006).

CONCLUSIONS

Preoperative DS, performed in all cases of CABG, followed by CEA under local anaesthesia in patients with critical carotid stenosis reduces the incidence of postoperative stroke.

Factors Associated With Presence of Ascending Aortic Atherosclerosis in CABG Patients

BACKGROUND

The indication for epiaortic scanning during coronary artery operation is still a matter of debate. Whether this test should be carried out selectively or on a routine basis is unclear. The aim of this study was to determine factors that predict the presence of atherosclerotic ascending aortic wall thickening in patients undergoing coronary artery bypass grafting (CABG).

METHODS

A total of 500 CABG patients underwent epiaortic scanning using a high-frequency linear ultrasonic probe. Maximum ascending aortic wall thickness was measured and correlated with patient-related variables.

RESULTS

Maximum ascending aortic wall thickness significantly correlated with age (p < 0.001), preoperative creatinine level (p = 0.004), European system for cardiac operative risk evaluation (EuroSCORE, p < 0.001), and maximum descending aortic wall thickness (p < 0.001). Body mass index and left ventricular ejection fraction showed no correlation with maximum ascending aortic wall thickness. Of the categorical variables, hypertension (p = 0.02), unstable angina (p = 0.04), chronic obstructive pulmonary disease (p = 0.02), cerebrovascular disease (p < 0.001), and peripheral vascular disease (p < 0.001) were associated with increased ascending aortic wall thickness whereas sex, diabetes, acute cases, and previous cardiac operation were not. Multivariate analysis revealed maximum descending aortic wall thickness (p < 0.001), cerebrovascular disease (p = 0.03), and peripheral vascular disease (p = 0.04) as independent variables significantly associated with maximum ascending aortic wall thickness.

CONCLUSIONS

If epiaortic scanning is not carried out routinely for detection of ascending aortic arteriosclerosis it should at least be performed in patients with old age, hypertension, unstable angina, chronic obstructive pulmonary disease, cerebrovascular disease, peripheral vascular disease, elevated creatinine levels, higher EuroSCOREs, and increased wall thickness of the descending aorta.

The Use of 3D Epiaortic Scanning to Enhance Evaluation of Atherosclerotic Plaque in the Ascending Aorta: A Case Series

Transesophageal echocardiography (TEE) is becoming the standard of practice for cardiopulmonary bypass (CPB) surgery. Unfortunately, large sections of the ascending aorta are not visible on TEE, and epiaortic scanning has proven superior to TEE and aortic palpation in determining the extent of plaque in the ascending aorta. The recently introduced x4 3-dimensional (3D) ultrasound probe allows both real time 3D imaging and gated acquisition sequences. We present a case series in which 3D ultrasound was used for epiaortic imaging in patients undergoing elective cardiac surgery, and we discuss the benefits and limitations of this imaging modality.

Propensity case-matched analysis of off-pump coronary artery bypass grafting in patients with atheromatous aortic disease

OBJECTIVE

Atheromatous aortic disease is a risk factor for excessive mortality and stroke in patients undergoing coronary artery bypass grafting. Outcomes of off-pump coronary artery bypass grafting and coronary artery bypass grafting with cardiopulmonary bypass in patients with severe atheromatous aortic disease were compared by propensity case-match methods.

METHODS

Routine intraoperative transesophageal echocardiography identified 985 patients undergoing isolated coronary artery bypass grafting with severe atheromatous disease in the aortic arch or ascending aorta. Off-pump coronary artery bypass grafting was performed in 281 patients (28.5%). Propensity matched-pairs analysis was used to match patients undergoing off-pump coronary artery bypass grafting (n = 245) with patients undergoing coronary artery bypass grafting with cardiopulmonary bypass.

RESULTS

Univariate analysis revealed decreased hospital mortality (16/245, 6.5% vs 28/245, 11.4%; P =.058) and stroke prevalence (4/245, 1.6% vs 14/245, 5.7%; P =.03) in off-pump coronary artery bypass grafting compared with coronary artery bypass grafting with cardiopulmonary bypass. Freedom from any postoperative complication was higher in off-pump coronary artery bypass grafting compared with coronary artery bypass grafting with cardiopulmonary bypass (226/245, 92.2% vs 196/245, 80.0%; P <.001). Multivariable analysis of preoperative risk factors showed that increased hospital mortality was associated with coronary artery bypass grafting with cardiopulmonary bypass (odds ratio = 2.7; P =.01), fewer grafts (P =.05), acute myocardial infarction (odds ratio = 11.5; P <.001), chronic obstructive pulmonary disease (odds ratio = 2.4; P =.03), previous cardiac surgery (odds ratio = 10.2, P =.05), and peripheral vascular disease (odds ratio = 2.1; P =.05). Cardiopulmonary bypass was the only independent risk factor for stroke (odds ratio = 3.6, P =.03). At 36 months' follow-up, comparable survival was observed in the off-pump coronary artery bypass grafting and coronary artery bypass grafting with cardiopulmonary bypass groups (74% vs 72%). Multivariable analysis revealed that renal disease (P <.001), advanced age (P <.001), previous myocardial infarction (P =.03), and lower number of grafts (P =.02) were independent risks for late mortality.

CONCLUSIONS

Patients with severe atherosclerotic aortic disease who undergo off-pump coronary artery bypass grafting have a significantly lower prevalence of hospital mortality, perioperative stroke, and overall complications than matched patients who underwent coronary artery bypass grafting with cardiopulmonary bypass. Routine intraoperative transesophageal echocardiography identifies severe atheromatous aortic disease and directs the choice of surgical technique.

Predictive Value of Inflammatory and Hemostatic Parameters, Atherosclerotic Risk Factors, and Chest X-Ray for Aortic Arch Atheromatosis

BACKGROUND AND PURPOSE

Aortic arch atheromatosis (AAA) is a common cause of cerebral embolism. Transesophageal echocardiography (TEE) shows not only the extension of atherosclerotic plaques but also the mobility of superimposed thrombi. In most cases AAA is only detected after the embolic event. This study was therefore designed to identify predictive factors for AAA.

METHODS

One hundred seven consecutive patients referred for routine TEE were included in the study. Patients on warfarin therapy, with a history of recent surgery, or with any signs of infectious, immunological, or malignant diseases were excluded.

RESULTS

Diabetes mellitus carried the highest risk for AAA (odds ratio, 3.0), followed by hyperlipidemia (2.5) and arterial hypertension (2.3). Age >70 years was accompanied with a 1.8-fold increased risk. Patients with aortic calcifications on standard chest x-ray had a 4.6-fold higher prevalence. Severe AAA was associated with higher levels of C-reactive protein (14.6+/-14.1 versus 4.9+/-7.2 mg/L), fibrinogen (4.20+/-1.22 versus 3.45+/-1.29 mg/L), plasmin/antiplasmin complexes (728+/-297 versus 453+/-243 microg/L), and D-dimers (980+/-652 versus 444+/-349 microg/L).

CONCLUSIONS

AAA is accompanied by elevation of inflammatory and hemostatic parameters. Patients with classic cardiovascular risk factors and aortic calcifications on chest x-ray have a higher prevalence. Further prospective studies are now warranted to establish a risk score to identify patients in whom TEE screening should be undertaken.

Diabetes and evidence of atherosclerosis are major risk factors for adverse outcome after elective thoracic aortic surgery

BACKGROUND

To predict risk after elective repair of ascending aorta and aortic arch aneurysms, we studied 464 consecutive patients.

METHODS

Adverse outcome (stroke or hospital death) was analyzed in 372 patients who underwent proximal repair and 92 patients who underwent aortic arch replacement from 1986 to the present. Preoperative risk factors with a P value less than.2 in a univariate analysis were entered into a multivariate model, and an equation incorporating independent risk factors was derived separately for proximal aorta and arch surgery.

RESULTS

Age more than 65 years (P =.04), diabetes (P =.02), cause (P =.01), and prolonged total cerebral protection time (duration of hypothermic circulatory arrest and selective cerebral perfusion, P =.001) were significant univariate risk factors for elective proximal aortic repair. Diabetes (P =.005, odds ratio 5.1), atherosclerosis (P =.003, odds ratio 4.0), and dissection (P =.048, odds ratio 2.5) were independent factors. For elective arch surgery, female sex (P =.07), age more than 65 years (P =.04), coronary artery disease (P =.02), diabetes (P =.06), cause (P =.07), and prolonged total cerebral protection time (P =.025) were univariate risk factors. Female sex (P =.05, odds ratio 4.7), coronary artery disease (P =.02, odds ratio 6.5), diabetes (P =.13, odds ratio 4.0), and total cerebral protection time (P =.03, odds ratio 1.02/min) were independent factors. To calculate risk of adverse outcome (P), enter 1 if factor is present, 0 if absent, and estimate total cerebral protection time (in minutes). [equation: see text].

CONCLUSION

In this large series of patients, the presence of diabetes and manifestations of atherosclerosis emerge as extremely important risk factors for adverse outcome after ascending aorta or arch surgery, displacing age. Multivariate equations derived from these data allow more precise calculation of risk for each individual contemplating elective surgery.

Overview of transesophageal echocardiography for the chest physician

Transesophageal echocardiography (TEE) is a growing technology that is frequently utilized in the critical care setting by intensivists, surgeons, anesthesiologists as well as specialists in cardiovascular diseases. The clinical application of TEE continues to emerge, and the indications and diagnostic utility of this technology as currently available are summarized in this review.

Modification of surgical technique for ascending aortic atherosclerosis: impact on stroke reduction in coronary artery bypass grafting

OBJECTIVE

Use of epiaortic scanning in coronary surgery is still a matter of debate. It is unclear whether the findings obtained by epiaortic scanning lead to effective changes in surgical technique that may reduce stroke rates.

METHODS

Epiaortic scanning was performed in 352 patients undergoing primary coronary artery bypass grafting before opening the pericardium using a 7.5-MHz ultrasonic probe. In the presence of moderate atherosclerosis (maximum aortic wall thickness of 3 to 5 mm), primarily single aortic crossclamping was carried out. In cases of severe sclerosis (maximum aortic wall thickness > 5 mm), aortic no-touch techniques on the beating heart were used.

RESULTS

The degree of ascending aortic atherosclerosis was normal or mild in 151 patients (42.9%), moderate in 167 patients (47.5%), and severe in 34 patients (9.6%). The operative technique was modified in 31.1% of patients with moderate aortic sclerosis and in 91.2% of patients with severe aortic sclerosis. Perioperative mortality was 0.0% for mild disease, 3.0% for moderate disease, and 8.8% for severe disease (P =.005). Corresponding stroke rates reached 2.0%, 2.4%, and 2.9% (P =.935). Logistic regression adjusting for EuroSCORE showed that ascending aortic atherosclerosis was an independent predictor of perioperative mortality (P =.013, odds ratio 1.67, confidence interval 1.11-2.50). The influence of aortic disease on the stroke prevalence was probably due to chance (P =.935), demonstrating a potentially positive effect of operative modifications concerning stroke caused by aortic manipulation.

CONCLUSIONS

We conclude that intraoperative screening of coronary artery bypass grafting patients by epiaortic scanning can reveal useful information about the operative risk and with an aortic no-touch concept, perioperative stroke rates in high-risk patients may be lower than predicted.

Endoluminal AAA repair using intravascular ultrasound for graft planning and deployment: a 2-year community-based experience

PURPOSE

To examine the effectiveness of intravascular ultrasound (IVUS) and digital subtraction angiography (DSA) for preoperative planning and intraoperative deployment of stent-grafts to treat abdominal aortic aneurysms.

METHODS

One hundred seventy patients (143 men; mean age 73.6+/-7.2 years, range 51-89) underwent successful DSA and IVUS to determine suitability for stent-graft repair. Patients subsequently received the AneuRx (n=157) or Ancure (n=13) device; intraprocedural IVUS was used to survey the proximal endograft for proper apposition to the aortic wall.

RESULTS

Reliable preoperative IVUS measurements were obtained in all patients. Plaque morphology was assessed in 140 (82.3%) aortic necks; in 36 (25.7%), preoperative IVUS showed high-grade atherosclerotic plaque in the nonaneurysmal abdominal aortic neck. The procedure was successful in 168 (98.8%) cases (1 [0.6%] acute conversion and 1 access failure). There were 2 (1.2%) periprocedural deaths related to bowel ischemia. Four (2.3%) patients developed graft occlusion/kinking and 2 (1.2%) developed renal failure requiring dialysis within 30 days. Multivariate logistic regression analysis revealed that female gender (p=0.0247), a short nonaneurysmal aortic neck (p=0.0185), and presence of high-grade atherosclerotic plaque (p=0.0185) correlated with major acute complications. Over a mean 10.4-month follow-up (range 1-25), 11 patients died of unrelated causes; there was no known AAA rupture or device failure. The Kaplan-Meier estimate of survival at 1 year was 91.0%+/-2.8%. Sixteen (9.4%) patients underwent 17 secondary procedures for endoleak or graft limb occlusion at a mean 5.4 months after stent-graft repair (freedom from secondary intervention at 1 year 86.5%+/-3.2%).

CONCLUSIONS

Our findings suggest that IVUS may identify patients at increased risk of major adverse complications following endovascular repair. The combination of IVUS and DSA for endoluminal stent-graft planning and placement provides excellent short- and mid-term patient outcomes.

Impact of single clamp versus double clamp technique on neurologic outcome

BACKGROUND

Atherosclerotic disease of the aorta has been identified as a risk factor for neurologic complications following coronary artery bypass grafting (CABG) due to the use of aortic clamping and manipulation. We reviewed a change from double clamp to single clamp technique to determine its impact on neurologic outcomes.

METHODS

Patients undergoing isolated CABG by a single surgeon were identified as having double clamp technique (DCT) (aortic cross clamp + sidebiting clamp) or single clamp technique (SCT) (aortic cross clamp only). Data were collected by study personnel and clinicians to determine stroke and neurologic injury (confusion, delirium, seizure, altered mental status, and agitation) outcomes for 461 patients.

RESULTS

Two hundred seventy-two patients had DCT and 189 patients had SCT performed. There were no differences in mean age, previous stroke, hypertension, or diabetes. Intraoperatively, patients with SCT had shorter bypass times (115 minutes vs 128 minutes, p = 0.001), longer aortic cross clamp time (89 minutes vs 80 minutes, p = 0.001), fewer coronary grafts (2.8 vs 3.1, p = 0.001), and had higher mean arterial blood pressure on cardiopulmonary bypass (76 mm Hg vs 69 mm Hg, p = 0.001). Postoperatively, the SCT group had fewer strokes (1.1% vs 2.9%, NS), and neurologic injuries (3.2% vs 9.6%, p = 0.008). By multivariate analysis, the factors that were related to neurologic injury were DCT (p = 0.04), age (p = 0.001), and number of coronary grafts (p = 0.03).

CONCLUSIONS

This experience suggests that the use of the SCT may be important in reducing neurologic injury following CABG.

Atheroembolism in cardiac surgery

BACKGROUND

Atheroembolism is a recognized complication of cardiac surgery, but its incidence and various outcomes have not been completely described. A retrospective study was undertaken to better characterize the syndrome.

METHODS

Records of 49,377 autopsies and surgical specimens from the Johns Hopkins Hospital between 1973 and 1995 were reviewed. Three hundred twenty-seven patients (0.7%) had an identifiable atheroembolism on histologic examination. Of these patients, 29 (0.2%) had undergone a cardiac surgical procedure within 30 days of autopsy or surgical resection. Patient charts and pathology specimens were reviewed for operative findings, postoperative outcomes, and histology.

RESULTS

Six of the 29 patients (21%) had atheroembolism to the heart, 7 patients (24%) had embolism to the central nervous system, 19 patients (66%) had embolism to the gastrointestinal tract, 14 patients (48%) had embolism to one or both kidneys, and 5 patients (17%) had embolism to a lower extremity. Sixteen patients (55%) had atheroembolism in two or more areas. In 6 patients (21%), death was directly attributable to atheroembolism, including intraoperative cardiac failure from coronary embolism (n = 3), massive stroke (n = 2), and extensive gastrointestinal embolization (n = 1).

CONCLUSIONS

Atheroembolism in cardiac surgery has a broad spectrum of clinical presentations, including devastating injuries and death. Although the true incidence is probably underestimated in this retrospective study, the high attendant mortality and morbidity of atheroembolism have been documented. Improvements in outcome are likely to be associated with preoperative identification of patients at high risk, modifications of perfusion technique, and interventions to minimize secondary thrombosis and progressive organ ischemia.

Postcardiac surgery complications: association of acute renal dysfunction and atrial fibrillation

Postoperative creatinine increase is associated with adverse outcome after cardiac surgery. Although postoperative stroke and renal dysfunction are associated after cardiac surgery, suggesting a common systemic insult, a similar assessment of atrial fibrillation and renal dysfunction has not been performed. Therefore, we tested the hypothesis that patients with new-onset atrial fibrillation complicating coronary bypass surgery have a greater postoperative creatinine increase. Data were obtained for 453 elective coronary bypass surgery patients with no history of atrial fibrillation. Multivariate regression analyses of factors associated with peak fractional change in creatinine demonstrated a two-way interaction between age and atrial fibrillation (variable estimate, -1.1; P = 0.002). Similar results were obtained in a secondary multivariate model analyzing factors associated with peak postoperative creatinine (variable estimate, -0.01; P = 0.04). We confirmed our hypothesis that patients with new-onset atrial fibrillation are more likely to have acute renal dysfunction after cardiac surgery. The association of atrial fibrillation and creatinine increase diminishes with advancing age. These data are consistent with a common pathophysiology that contributes in an age-dependent fashion to the etiology of both acute renal dysfunction and atrial fibrillation after coronary bypass surgery.

IMPLICATIONS

We found an independent association between new-onset atrial fibrillation and postoperative creatinine increase that is influenced by age. The degree to which atrial fibrillation is associated with postoperative creatinine increase diminishes with advancing age. This interaction suggests that a common etiology for these two complications may be more important in younger patients.