Stroke in cardiac surgical patients: determinants and outcome

Outcome of heart surgery procedures in octogenarians: is age really not an issue?

Survival rates are a well-known marker for quality performance of a cardiac surgery department, as well as standard of procedures, freedom of reoperation, postoperative complications, length of hospital stay, improvement in New York Heart Association classification and quality of life after surgery. Until recently there has not been any great interest of surgeons in topics concerning the costs of postoperative care, as long as the results were successful. However, satisfactory results after cardiac surgery in aged people require successful procedures, as well as meticulous perioperative care. The expenses of healthcare are constantly growing and approaches to optimize costs in all departments of medicine have a high priority. Exact evaluation of comorbidities and prevention of complications in aged people, as well as attentive strategies concerning expenses, may help to reduce mortality, postoperative complications and costs.

Risk Estimates of Stroke After Coronary Artery Bypass Graft and Carotid Endarterectomy

Neurologic complications of cardiovascular surgeries are well documented in the literature. Neurologic deficits may be mild and reversible or may be associated with permanent neurologic deficit. The incidence and severity of such complications vary according to the type of surgical procedure and usually correlate with patients' preoperative general medical condition, duration of surgeries, and intraoperative complications.

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.

Changes in jugular bulb oxygen saturation during off-pump coronary artery bypass graft surgery

BACKGROUND

The effect of haemodynamic derangement during coronary artery anastomosis in off-pump coronary artery bypass surgery on cerebral blood flow has not been elucidated. Jugular bulb oxygen saturation is a useful indicator of cerebral blood flow provided that the cerebral metabolic rate is constant. This study was designed to evaluate the changes in jugular bulb oxygen saturation during off-pump coronary artery bypass surgery.

METHODS

With IRB approval, 48 patients were included. After anaesthesia, an 18-G catheter was introduced into the jugular bulb. Haemodynamic variables and oxygen profiles from gas analysis of jugular bulb blood and arterial blood were obtained: after sternotomy (baseline); at 5 min after the beginning of the anastomosis of the left anterior descending artery, obtuse marginal artery, and right coronary artery; and after sternal closure.

RESULTS

Cardiac index and mixed venous oxygen saturation decreased significantly during anastomosis of all three arteries compared to the baseline value. Although the changes in jugular bulb oxygen saturation during anastomosis were statistically significant compared to its baseline value, jugular bulb oxygen saturation remained within normal limit throughout the study.

CONCLUSIONS

Jugular bulb oxygen saturation, which represents the global cerebral oxygenation, was well maintained during the anastomosis of all coronary arteries despite significant haemodynamic changes during off-pump coronary artery bypass (OPCAB).

The use of the stroke risk index to predict neurological complications following coronary revascularisation on cardiopulmonary bypass

The aim of this study was to investigate the validity of the stroke risk index (SRI) in identifying patients who develop a stroke following coronary artery bypass grafting on cardiopulmonary bypass. Retrospective data were analysed from 6846 patients who underwent adult coronary artery surgical procedures on cardiopulmonary bypass between 1997 and 2003. Patients were risk stratified pre-operatively using the SRI assessment model into low (Group A < or = 50), medium (Group B, 51-100) and high risk (Group C, > 100). A total of 217 patients (3.2%) with a mean age 65.9 +/- 11.7 years developed adverse neurological events following surgery. The CNS injury risk was 4% in Group A, 23% in Group B, and 8% in Group C. Pre-operatively, patients in Group B were older (p < 0.05), had a greater proportion of redo operations (OR 3.02; p < 0.001), diabetes mellitus (OR 2.51; p < 0.05), hypertension (OR 1.64; p < 0.01), myocardial infarction (OR 3.79; p < 0.05), ejection fraction < 30% (OR 1.46; p < 0.01) and absence of sinus rhythm (OR 2.52; p < 0.05) when compared with their counterparts. CNS events increased the patients' hospital stay by 40% in Groups A and C (p = 0.04) and 72% in Group B (p < 0.001). Only 31% returned home, compared with 85% of patients without cerebral complications (p < 0.001). These findings demonstrate that factors such as a pre-operative history of redo procedures, myocardial infarction, ejection fraction < 30% and absence of sinus rhythm play an important role in identifying the at-risk population. We conclude, therefore, that a further refinement and validation of the SRI is necessary.

Brain Magnetic Resonance Imaging Abnormalities following Off-Pump Cardiac Surgery

Background: Neurological and cognitive deficits are known complications after coronary artery bypass surgery (CABG) and are believed to be secondary to brain ischemia. Diffusion-weighted magnetic resonance imaging (DW-MRI) of the brain is especially sensitive and can depict ischemic areas that may not be evident clinically or with conventional MRI. Abnormalities found at brain MRI following CABG performed with cardiopulmonary bypass (ie, on pump) have been reported, but data are limited for CABG performed without use of cardiopulmonary bypass (ie, off pump). The objective of this study was to determine the rate of DW-MRI detection of brain lesions following off-pump CABG. Methods and Results: Sixteen patients consecutively undergoing off-pump CABG underwent DW-MRI prior to and after surgery. A neuroradiologist blinded to patient data coded the location and size of lesions. Neurological function was assessed with the National Institutes of Health Stroke Scale. Five (31%) of the patients had new focal ischemic lesions found at postoperative DW-MRI. Risk factors for postoperative brain ischemic lesions were similar between patients with and those without lesions found at DW-MRI. No patient had a definite clinical stroke after surgery. Conclusions: Ischemic lesions found at DW-MRI are seen after off-pump CABG at a rate similar to that reported for CABG with cardiopulmonary bypass. This finding suggests that these lesions are not totally due to cardiopulmonary bypass. Further prospective clinical studies would be helpful for determining which factors are causally related to brain ischemia following CABG.

Herzchirurgie im Alter

Due to demographic changes in average life expectancy, the age of patients undergoing cardiac surgery is increasing. We have reviewed the literature to analyse whether and how far octogenarians benefit from cardiac surgical procedures. Different studies analysed the outcome of patients in different age groups after cardiac surgery. Octogenarians can undergo cardiac surgical procedures at a reasonable risk. The perioperative mortality and other postoperative complications are strongly dependent on comorbidities rather than on patients' age. Elderly patients benefit from improved functional status and quality of life.

Short-Term Complications and Resource Utilization in Matched Subjects After On-Pump or Off-Pump Primary Isolated Coronary Artery Bypass

• Background Studies suggest that patients who undergo off-pump coronary artery bypass grafting (OPCABG) have fewer short-term complications and use fewer inpatient resources than do patients who undergo standard coronary artery bypass grafting (CABG) with extracorporeal circulation. However, dissimilarity between groups in risk factors for complications has hindered interpretation of results.

• Objectives To compare the prevalence of selected complications (atrial fibrillation, stroke, reoperation, and bleeding) and inpatient resource utilization (length of stay, discharge disposition, total charges) between subjects undergoing primary isolated CABG or OPCABG who were matched with respect to key risk factors.

• Methods Retrospective, causal-comparative survey conducted in 1 center for 18 months. Patients who underwent primary isolated CABG or OPCABG were matched for sex, age (within 2 years), left ventricular ejection fraction (within 0.05), and graft-patient ratio (exact match) and compared for prevalence of new-onset atrial fibrillation, stroke, reoperation within 24 hours, and bleeding. Statistical analysis included Wilcoxon and t tests for paired comparisons.

• Results The sample (107 matched pairs) was 63% male, with a mean age of 66 (SD 9.5) years, a mean left ventricular ejection fraction of 0.51 (SD 0.13), and a mean graft-patient ratio of 3.41 (SD 0.74). The 2 groups did not differ significantly in New York Heart Association class (P = .43), Acute Physiology and Chronic Health Evaluation III score (P = .22), postoperative β-blocker use (P = .73), or comorbid conditions. None of the complications examined differed significantly between pairs.

• Conclusion Patients with comparable risk profiles have similar prevalences of selected complications after CABG and OPCABG.

Improved Health-related Quality of Life after Coronary Artery Bypass Grafting Is Unrelated to Use of Cardiopulmonary Bypass

This prospective study was instituted to assess whether the use of the on-pump method or the off-pump method affects changes in health-related quality of life (QOL) as evaluated a year after coronary artery bypass graft (CABG) surgery. Data including preoperative risk factors and postoperative morbidity up to discharge were collected from 508 CABG patients operated in the Heart Center of a university hospital and further treated in secondary referral hospitals. Four hundred and fifty-two (89.0%) patients underwent operation with the on-pump method and 56 (11.0%) with the off-pump method, i.e., without cardiopulmonary bypass (CPB). The RAND-36 Health Survey (RAND-36) was used as indicator of QOL. The primary outcome measure was a change in the physical component summary (PCS) and mental component summary (MCS) from the RAND-36. Symptomatic status was estimated according to New York Heart Association (NYHA) class. Assessments were made preoperatively and repeated 12 months later. The majority of patients operated on-pump (85.6%) and off-pump (92.9%) had a favorable outcome without major complications (p = 0.136). The present data showed significant improvement (p < 0.001) in all eight domains of QOL following on-pump CABG. Likewise, off-pump patients improved in all eight aspects, and the change was statistically significant in six dimensions. A highly significant (p < 0.001) pattern of change was seen in the RAND-36 MCS and PCS scores in both operative groups. Differences between the groups were nonsignificant. We conclude that most patients experience significant improvement in health-related QOL during the first year after CABG, and that cardiopulmonary bypass has no effect on patients' subsequent health-related QOL, but its use depends on specific indications.

Predictors of stroke in patients undergoing coronary artery bypass grafting surgery: A prospective, nested, case-control study

The objective of the present study was to assess the risk factors for stroke in patients undergoing coronary artery bypass grafting (CABG) surgery. We conducted a nested case-control study from a 9-year, prospective hospitalization cohort (n = 6245). Inclusion in the cohort included CABG between October 1993 and June 2002. Exclusion criteria included any other simultaneously performed surgery. Cases were defined as patients who underwent CABG and experienced a stroke (171 cases, 2.7% of the total), and controls were patients who underwent CABG without a stroke. Cases were matched to controls at a ratio of 1:3 (513 controls). The 39 predictor variables were pump time, body surface area, creatinine, previous percutaneous transcoronary angioplasty (PTCA), clamp time, coronary perfusion time, previous cardiac surgeries, hypertension, race, sex, previous myocardial infarction, family history of coronary disease, history of cerebrovascular disease, preoperative neurologic disease, pulmonary hypertension, aortic disease, previous intervention within 30 days, angina history, bleeding history, previous vascular surgery, diabetes, age, myocardial findings, chronic obstructive pulmonary disease, New York Heart Association class, previous gastrointestinal disease, current vascular disease, systemic diseases, vessels at last PTCA, PTCA result, current smoking, tobacco history, dialysis, current anticoagulant therapy, character of operation, left ventricular hypertrophy, hypercholesterolemia, and chronic corticosteroid therapy. There were 13 significant predictors of stroke. Regression analysis revealed 3 independent predictors of stroke: age >70 years (odds ratio [OR], 4.61; 95% confidence interval [CI], 2.84-6.07), poor preoperative neurologic status (OR, 4.24; 95% CI, 2.02-5.79), and previous cardiac surgery (OR, 1.75; 95% CI, 1.05-2.91). We conclude that in patients undergoing CABG surgery, the independent predictors for stroke, in order of risk, are age >70 years, poor preoperative neurologic status, and previous cardiac surgery.

Stroke rate of off-pump coronary artery bypass; aortocoronary bypass versus in-situ bypass

Off-pump coronary artery bypass (OPCAB) using in-situ grafts does not require aortic manipulation, and it is theoretically free from the risk of stroke. Because of the limited availability of in-situ grafts, aortocoronary bypass has been conducted in addition to in-situ grafting. In this paper, the authors prospectively investigated whether or not on aortocoronary bypass increases the incidence of stroke after off-pump bypass. Perioperative data were collected prospectively from patients who underwent isolated off-pump bypass at their hospital group between March 1997 and February 2002. The patients were divided into 2 groups; group AC (patients with at least 1 aortocoronary bypass, n = 280) and group IS (patients with all in-situ grafts, n = 234). Patients with 3-vessel disease more frequently underwent aortocoronary bypass and patients with a history of stroke, calcified ascending aorta, or renal failure more often underwent in-situ graft. The number of distal anastomoses was greater in group AC (3.5 +/- 1.0) than in group IS (2.7 +/- 1.1), p < 0.0001. Patient recovery and complication rates were similar, including the occurrence of postoperative stroke: 3.0% (7/234) in group IS vs 0.7% (2/280) in group AC, p = 0.051, NS. The graft patency and remote results were not significantly different between the 2 groups. Side clamping of the aorta used in off-pump aortocoronary bypass does not increase the risk of postoperative strokes compared to in-situ bypass. Postoperative stroke after OPCAB may depend on the patient's preoperative comorbidities.

Perioperative stroke in coronary artery bypass patients

BACKGROUND AND AIMS

Stroke has remained one of the most frustrating complications in coronary artery bypass surgery (CABG). The purpose of this study was to describe the incidence and correlates of stroke in CABG patients operated on in a hospital with low annual volume of open-heart surgery procedures. The aim was moreover to clarify subsequent outcome and self-reported satisfaction-based quality of life of patients who had experienced a stroke.

MATERIAL AND METHODS

The material was a cohort of 1318 consecutive CABG patients operated on over a 6-year period. Data was collected prospectively but the final analysis was retrospective. Questionnaires supplemented the estimation of survival and subsequent functional status.

RESULTS

The incidence of stroke was 2.6 %. Age > 70 years, chronic obstructive pulmonary disease (COPD), peripheral vascular disease (PVD), cerebral vascular disease (CVD), number of aortic anastomoses and significant atherosclerosis of the ascending aorta were univariate predictors of stroke. Postoperative stroke was experienced in 55.9% of cases delayed appearing from 2nd postoperative day on. Stroke patients had a higher rate of mortality (14.7% vs. 1.0%, p = 0.001) and poorer survival than no-stroke patients (82.4% and 97.4% at one year and 61.2% and 89.7% at six years, p < 0.001).

CONCLUSIONS

The incidence of stroke seems to be on the same level in CABG patients from a low volume hospital as in reports from centres with a high volume of annual procedures. Stroke predicts higher mortality, longer intensive care unit (ICU) stay, longer hospitalisation and poorer survival. A relatively high number of stroke patients need permanent institutional care. Satisfaction-based quality of life in CABG patients also remains on a lower level in comparison to patients without neurological complications.

Subdural hemorrhagic injury after open heart surgery

We report two cases of acute subdural hematoma after cardiac surgery using cardiopulmonary bypass. In both patients, emergency removal and drainage of a subdural hematoma was performed by neurosurgeons, and complete recovery followed. Subdural hemorrhagic brain injury after cardiac surgery is rare and devastating; however, we consider early diagnosis and proper treatment to be effective because organic brain damage did not occur.

Rehabilitation of postcardiac surgery stroke patients. Progress, outcomes, and comparisons with other stroke patients

OBJECTIVE

To examine the demographics, progress, and functional outcomes of all postcardiac surgery stroke patients admitted to the rehabilitation unit of an acute, tertiary general hospital over a 5-yr period and to compare this cohort with an age-matched control group of other stroke patients admitted during the same period.

DESIGN

A retrospective chart review of 47 postcardiac surgery stroke and a matched control group of other stroke patients admitted to the rehabilitation unit.

RESULTS

The mean age of the postcardiac surgery stroke patients was 70.80 +/- 8.37 yr, with 60% of patients being male. Their average length of stay on the rehabilitation unit was 15.64 +/- 11.96 days. Mean admit FIM total score was 65.64 +/- 16.33, with a discharge FIM total score of 86.77 +/- 18.93. Mean admit FIM motor score was 41.47 +/- 9.45, with a discharge FIM motor of 60.74 +/- 13.20. The other stroke group had significantly greater admit FIM total (P = 0.03), admit motor (P = 0.001), and discharge motor (P = 0.025) scores. FIM efficiency and motor and cognitive gains were comparable between the two groups. Length of stay on the rehabilitation unit was approximately 2 days less (P = 0.224) for the other stroke cohort. Ultimately, 39 (83%) of the postcardiac surgery stroke patients were discharged to the community compared with 45 (96%) of the other stroke patients (P = 0.19).

CONCLUSIONS

The majority of postcardiac surgery stroke patients successfully completed a comprehensive inpatient rehabilitation program. They had lower admit FIM total scores and admit and discharge FIM motor scores than the other stroke group and were almost as likely to ultimately return to the community.

Off-pump technique in coronary artery bypass grafting in elderly patients

BACKGROUND

The use of cardiopulmonary bypass (CPB) during coronary artery bypass grafting (CABG) is associated with substantial morbidity and mortality, especially in the elderly. The purpose of this study was to evaluate the feasibility of beating heart coronary artery revascularization in patients aged at least 80 years.

METHODS

A retrospective chart review was carried out for 17 patients aged over 80 years who underwent isolated off-pump CABG at the Tri-Service General Hospital, Taiwan, during the period July 1999 to December 2000. The demographic characteristics, operative data, postoperative results and short-term outcomes of patients were compared with those of 12 patients who underwent conventional CABG using CPB during the same time period.

RESULTS

The off-pump group consisted of 13 men and four women with a mean age of 82.2 +/- 0.9 years and an ejection fraction of 53.4 +/- 4.1%. The on-pump group consisted of eight men and four women with a mean age of 83.5 +/- 0.5 and an ejection fraction of 42.0 +/- 4.8%. The mean number of anastomoses performed per patient was 3.1 +/- 0.3 in the off-pump group and 3.0 +/- 0.14 in the on-pump group. There was no occurrence of stroke, myocardial infarction, re-entry for bleeding or renal failure among patients in the off-pump group. Intubation time (10.6 vs 48.4 h), intensive care unit stay (2.9 vs 4.2 days) and postoperative stay (12.7 vs 18.1 days) were significantly shorter in the off-pump group than in the on-pump group. No patient died in the off-pump group, whereas one patient died in the on-pump group.

CONCLUSIONS

The results of this study suggest that the off-pump technique is a safe and efficacious method for myocardial revascularization in elderly patients and that the short-term outcome obtained with this technique are promising. Our data suggest that the off-pump technique is preferable in these patients.

The Society of Thoracic Surgeons: 30-day operative mortality and morbidity risk models

BACKGROUND

Although 30 day risk-adjusted operative mortality (ROM) has been used for quality assessment, it is not sufficient to describe the outcomes after coronary artery bypass grafting (CABG) surgery. Risk-adjusted major morbidity may differentially impact quality of care (as complications occur more frequently than death) and enhance a surgical team's ability to assess their quality. This study identified the preoperative risk factors associated with several complications and a composite outcome (the presence of any major morbidity or 30-day operative mortality or both).

METHODS

For CABG procedures, the 1997 to 1999 Society of Thoracic Surgeons (STS) National Adult Cardiac Surgery Database was used to develop ROM and risk-adjusted morbidity (ROMB) models. Risk factors were selected using standard STS univariate screening and multivariate logistic regression approaches. Risk model performance was assessed. Across STS participating sites, the association of observed-to-expected (O/E) ratios for ROM and ROMB was evaluated.

RESULTS

The 30-day operative death and major complication rates for STS CABG procedures were 3.05% and 13.40%, respectively (503,478 CABG procedures), including stroke (1.63%), renal failure (3.53%), reoperation (5.17%), prolonged ventilation (5.96%), and sternal infection (0.63%). Risk models were developed (c-indexes for stroke [0.72], renal failure [0.76], reoperation [0.64], prolonged ventilation [0.75], sternal infection [0.66], and the composite endpoint [0.71]). Only a slight correlation was found, however, between ROMB and ROM indicators.

CONCLUSIONS

Used in combination, ROMB and ROM may provide the surgical team with additional information to evaluate the quality of their care as well as valuable insights to allow them to focus on areas for improvement.

Preoperative high leukocyte count: a novel risk factor for stroke after cardiac surgery

BACKGROUND

Stroke after cardiac surgery is a devastating complication. The relationship between white blood cell count (WBC) and perioperative cerebrovascular accident (CVA) has not been investigated. An effort was made to identify how preoperative WBC may relate to CVA development during or after cardiac surgery.

METHODS

Prospective data were collected from 7,483 patients who underwent coronary artery bypass grafting or valvular surgery or both. WBC was determined preoperatively and postoperatively. Differentiation of WBC was examined only preoperatively.

RESULTS

There were a total of 125 CVAs (10 transient ischemic attacks [TIAs], 115 strokes). WBC was significantly higher preoperatively and directly postoperatively in patients with stroke. Qualitative changes in preoperative WBC were also found in these patients (chi2; p < 0.001). The predictive power of the stepwise logistic regression model for CVA was greater when preoperative WBC was included. The risk for perioperative CVA increased starting at preoperative WBC of 9 x 10(9)/L (p = 0.044) and progressed in higher WBC ranges. WBC had a significant impact on CVA outcome (analysis of variance, p = 0.001).

CONCLUSIONS

Our studies have established the correlation between high preoperative WBC and stroke during or after cardiac surgery. Furthermore, elevated preoperative WBC was related to the clinical outcome of CVA. Preoperative measures aimed at preventing or treating conditions such as infections that may cause elevated WBC may be beneficial in the prevention of stroke during or after cardiac surgery.

Modeling stroke risk after coronary artery bypass and combined coronary artery bypass and carotid endarterectomy

BACKGROUND AND PURPOSE

The goals of this study were to compare the ability of statewide and institutional models of stroke risk after coronary artery bypass (CAB) to predict institution-specific results and to examine the potential additive stroke risk of combined CAB and carotid endarterectomy (CEA) with these predictive models.

METHODS

An institution-specific model of stroke risk after CAB was developed from 1975 consecutive patients who underwent nonemergent CAB from 1994 to 1999 in whom severe carotid stenosis was excluded by preoperative duplex screening. Variables recorded in the New York State Cardiac Surgery Program database were analyzed. This model (model I) was compared with a published model (model II) derived from analysis of the same variables using New York statewide data from 1995. Predicted and observed stroke risks were compared. These formulas were applied to 154 consecutive combined CAB/CEA patients operated on between 1994 and 1999 to determine the predicted stroke risk from CAB alone and thereby deduce the maximal added risk imputed to CEA.

RESULTS

Risk factors common to both models included age, peripheral vascular disease, cardiopulmonary bypass time, and calcified aorta. Additional risk factors in model I also included left ventricular hypertrophy and hypertension. Risk factors exclusive to model II included diabetes, renal failure, smoking, and prior cerebrovascular disease. Our observed stroke rate for isolated CAB was 1.7% compared with a rate predicted with model II (statewide data) of 1.56%. The observed stroke rate for combined CEA/CAB was 3.9%. When the Stony Brook model (model I) based on patients without carotid stenosis was used, the predicted stroke rate was 2.8%. When the statewide model (model II), which included some patients with extracranial vascular disease, was used, the predicted stroke rate was 3.4%. The differences between observed and predicted stroke rates were not statistically significant.

CONCLUSIONS

Estimation of stroke risk after CAB was similar whether statewide data or institution-specific data were used. The statewide model was applicable to institution-specific data collected over several years. Common risk factors included age, aortic calcification, and peripheral vascular disease. The observed differences in the predicted stroke rates between models I and II may be due to the fact that carotid stenosis was specifically excluded by duplex ultrasound from the patient population used to develop model I. Modeling stroke risk after CAB is possible. When these models were applied to patients undergoing combined CAB/CEA, no additional stroke risk could be ascribed to the addition of CEA. Such models may be used to identify groups at increased risk for stroke after both CAB and combined CAB/CEA. The ultimate place for CEA in patients undergoing CAB will be defined by prospective randomized trials.

High-dose glucose-insulin-potassium after cardiac surgery: a retrospective analysis of clinical safety issues

BACKGROUND

Metabolic treatment with insulin or glucose-insulin-potassium (GIK) has received attention in association with myocardial infarction, cardiac surgery and critical care. As a result of insulin resistance during neuroendocrine stress, doses of insulin up to 1 IU kg-1 b.w.*h are required to achieve maximal metabolic effects after cardiac surgery. The clinical experience with regard to safety issues of such a high-dose GIK regime in critically ill patients after cardiac surgery is reported.

METHODS

Retrospective, observational study involving all patients treated with high-dose GIK after cardiac surgery during one year in a cardiovascular center at a University Hospital.

RESULTS

Eighty-nine patients out of 854 adult patients undergoing cardiac surgery were treated with high-dose GIK. Mean age was 69 +/- 1 years, Higgins score 5.3 +/- 0.3. Preoperatively 31.4% had left ventricular function EF< or =0.35 and 32.5% had sustained a myocardial infarct during surgery. Mortality was 5.6% and the average ICU stay was 3.7 +/- 0.5 days. The main indication for GIK was intraoperative heart failure (69.7%). The average glucose infusion rate during the first 6 h was 4.22 +/- 0.15 and 4.91 +/- 0.14 mg kg-1 b.w.*min, respectively, in diabetic and non-diabetic patients (P = 0.023). Blood glucose and s-potassium control was acceptable.

CONCLUSIONS

The high-dose GIK regime allowed substantial amounts of glucose to be infused both in diabetic and critically ill patients with maintenance of acceptable blood glucose control. Provided careful monitoring, this regime can be safely used in clinical practice and deserves further evaluation for treatment of critically ill patients following cardiac surgery.

The short-term and long-term effects of warm or tepid cardioplegia

BACKGROUND

Clinical studies of myocardial protection rarely identify differences in hard clinical outcomes after surgery, either early or late, because most trials lack sufficient statistical power to deal with low-frequency events.

METHODS

Prospectively collected data concerning all isolated coronary bypass operations from November 1989 to February 2000 were analyzed to determine the effects of cold blood cardioplegia and warm or tepid blood cardioplegia on early and late outcomes after surgery. Warm blood cardioplegia was used in 4532 patients, whereas cold blood cardioplegia was used in 1532. The allocation of patients to receive warm blood cardioplegia and cold blood cardioplegia was random in 749 cases and according to surgeon preference in the remainder. Most patients in the cold blood cardioplegia group had surgery earlier in the time course of the study, and most in the warm blood cardioplegia group underwent surgery later.

RESULTS

Perioperative death, myocardial infarction, and death or myocardial infarction were all more common in the cold blood cardioplegia group than in the warm blood cardioplegia group (death 2.5% vs 1.6%, P =.027, adjusted odds ratio 1.45, 95% confidence interval 0.95-2.22, P =.09; myocardial infarction 5.4% vs 2.4%, P <.0001, adjusted odds ratio 1.86, 95% confidence interval 1.36-2.53, P <.0001; death or myocardial infarction 7.3% vs. 3.8%, P <.0001, adjusted odds ratio 1.70, 95% confidence interval 1.30-2.21, P <.0001). Actuarial survival at 60 months was 91.1% +/- 1.4% in the warm blood cardioplegia group and 89.9% +/- 1.3% in the cold blood cardioplegia group (P =.09), whereas freedom from death or myocardial infarction was 84.7% +/- 1.8% and 83.2% +/- 1.6%, respectively (P =.16). In multivariate models, cold blood cardioplegia was associated with poorer survival (risk ratio 1.30, 95% confidence interval 0.96-1.75, P =.09) and freedom from any death or late myocardial infarction (risk ratio 1.93, 95% confidence interval 1.56-2.39, P =.0001).

CONCLUSIONS

In 6064 patients undergoing isolated coronary artery bypass grafting, warm or tepid blood cardioplegia may be associated with better early and late event-free survivals than is cold cardioplegia.

Stroke after cardiac surgery: a risk factor analysis of 16,184 consecutive adult patients

BACKGROUND

Stroke remains a devastating complication after cardiac surgical procedures despite advances in perioperative monitoring and management. The purpose of this study was to determine the predictors of stroke in a large, contemporary cardiac surgery population.

METHODS

Prospective data on 16,184 consecutive patients undergoing cardiac surgery (coronary artery bypass grafting [CABG], n = 8,917; beating heart CABG, n = 1,842; aortic valve surgery, n = 1,830; mitral valve surgery, n = 708; double or triple valve surgery, n = 381; CABG and valve surgery, n = 2,506) between April 1996 and August 2001 were subjected to univariate and multivariate analysis. Stroke was defined as any new permanent (manifest stroke) or temporary neurologic deficit or deterioration (transient ischemic attack or prolonged reversible ischemic neurologic deficit) and was confirmed by computed tomography or magnetic resonance imaging whenever possible.

RESULTS

Overall incidence of stroke was 4.6% and varied between surgical procedures (CABG 3.8%; beating-heart CABG 1.9%; aortic valve surgery 4.8%; mitral valve surgery 8.8%; double or triple valve surgery 9.7%; CABG and valve surgery 7.4%). Of 63 patient-specific and treatment variables, 54 were found to have a significant univariate association with postoperative stroke. Multivariable analysis revealed 10 variables that were independent predictors of stroke: history of cerebrovascular disease, peripheral vascular disease, diabetes, hypertension, previous cardiac surgery, preoperative infection, urgent operation, CPB time more than 2 hours, need for intraoperative hemofiltration, and high transfusion requirement. Beating heart CABG was associated with a lower incidence of stroke in this multivariable analysis.

CONCLUSIONS

Identification of predictors for stroke is important for understanding the pathogenesis of this devastating complication as well as for developing preventative strategies. Although retrospective analyses can be subject to selection bias we believe beating heart CABG is associated with a lower incidence of stroke and may therefore improve patient outcomes.

Increased S100B in blood after cardiac surgery is a powerful predictor of late mortality

BACKGROUND

Long-term outcome in patients who suffered stroke after undergoing a cardiac operation has been investigated sparingly, but increased long-term mortality has been reported. S100B is a biochemical marker of brain cell ischemia and blood-brain barrier dysfunction. The aim of this investigation was to record the long-term mortality in consecutive patients undergoing cardiac operations and to explore whether increased concentrations of S100B in blood had a predictive value for mortality.

METHODS

Prospectively collected clinical variables, including S100B, in 767 patients who survived more than 30 days after a cardiac operation, were analyzed with actuarial survival analysis and 678 patients were analyzed with Cox multiple regression analysis.

RESULTS

Forty-nine patients (6.4%) were dead at follow-up (range, 18 to 42 months); 11.5% (88 of 767 patients) had elevated S100B 2 days after operation (range, 38 to 42 hours). The probability for death at follow-up was 0.239 if the S100B level was more than 0.3 microg/L, and 0.041 if it was less than 0.3 microg/L. The clinical variables independently associated with mortality were preoperative renal failure, preoperative low left ventricular ejection fraction, emergency operation, severe postoperative central nervous system complication, and elevated S100B values, which turned out to be the most powerful predictor.

CONCLUSIONS

Even slightly elevated S100B values in blood 2 days after cardiac operation imply a bad prognosis for outcome, and especially so in combination with any central nervous system complication.

Neurological outcomes in coronary surgery: independent effect of avoiding cardiopulmonary bypass

BACKGROUND

Recent studies examining neuroprotective effects of off-pump coronary artery bypass grafting (CABG) have shown inconsistent results. We examined our database to quantify the independent effects of avoidance of cardiopulmonary bypass (CPB) and aortic manipulation on neurologic outcomes after CABG.

METHODS

A total of 2,327 consecutive cases undergoing isolated CABG between April 1997 and May 2001 were identified at our two institutions. Patients were divided into three groups: on CPB, off-pump with aortic manipulation, and off-pump without aortic manipulation. To control for the confounding effects of other risk factors, we performed a multivariate logistic regression analysis. Potential covariates considered in the logistic model included age, sex, redo operations, diabetes, chronic obstructive pulmonary disease, neurologic disease, peripheral vascular disease, ejection fraction, and priority of operation.

RESULTS

A total of 1,210 cases were performed on CPB, compared with 520 off-pump with aortic manipulation, and 597 off-pump without aortic manipulation. The incidence of focal neurologic deficit was 1.6% (n = 19) in the on-pump group, 0.4% (n = 2) in the off-pump with aortic manipulation group, and 0.5% (n = 3) for the off-pump without aortic manipulation group (p for trend = 0.027). The results of the multivariate logistic regression analysis demonstrated that use of CPB was a risk factor for focal neurologic deficit, with an odds ratio of 3.82 (95% confidence interval, 1.41 to 10.34; p = 0.005). Aortic manipulation did not significantly influence neurologic outcome in off-pump patients.

CONCLUSIONS

Off-pump operation, with or without aortic manipulation, reduces adverse neurologic outcomes compared with on-pump procedures.

Risk factor analysis of early and delayed cerebral complications after cardiac surgery

OBJECTIVE

To report the incidence, severity, and possible risk factors for early and delayed cerebral complications.

DESIGN

Retrospective study.

SETTING

Linköping University Hospital, Sweden.

PARTICIPANTS

Consecutive patients who underwent cardiac surgery in the period July 1996 through June 2000 (n = 3,282).

INTERVENTIONS

A standard cardiopulmonary bypass (CPB) technique was used for most patients. Postoperative anticoagulant treatment included heparin or anti-Xa dalteparin. Patients undergoing coronary artery bypass graft surgery received acetylsalicylic acid, and patients undergoing valve surgery received warfarin.

MEASUREMENTS AND MAIN RESULTS

Cerebral complications occurred in 107 patients (3.3%). Of these, 60 (1.8%) were early, and 33 (1.0%) were delayed, and in 14 (0.4%) patients the onset was unknown. There were 37 variables in univariate analysis (p < 0.15) and 14 variables in multivariate analysis (p < 0.05) associated with cerebral complications. Predictors of early cerebral complications were older age, preoperative hypertension, aortic aneurysm surgery, prolonged CPB time, hypotension at CPB completion and soon after CPB, and postoperative arrhythmia and supraventricular tachyarrhythmia. Predictors of delayed cerebral complications were female gender, diabetes, previous cerebrovascular disease, combined valve surgery and coronary artery bypass graft surgery, postoperative supraventricular tachyarrhythmia, and prolonged ventilator support. Early cerebral complications seem to be more serious, with more permanent deficits and a higher overall mortality (35.0% v 18.2%).

CONCLUSION

Most cerebral complications had an early onset. The results of this study suggest that aggressive antiarrhythmic treatment and blood pressure control may imfurther prove the cerebral outcome after cardiac surgery.

Impact of aortic manipulation on incidence of cerebrovascular accidents after surgical myocardial revascularization

BACKGROUND

The impact of aortic manipulation on incidence of cerebrovascular accidents (CVAs) was evaluated in patients who underwent myocardial revascularization.

METHODS

From January 1988 to December 2000, 4,875 patients had coronary operations; 33 who survived less than 24 hours and 19 who had aortic cannulation without cross-clamping were excluded. According to the degree of aortic manipulation, patients were divided into two groups: group A, aortic cannulation, cross-clamping, with (A1, n = 597) or without (A2, n = 2,233) side-clamping, and group B, with (B1, n = 460) or without (B2, n = 1,533) side-clamping. Patients in group A (n = 2,830) were operated on with and patients in group B (n = 1,993) were operated on without cardiopulmonary bypass (CPB). Univariate and multivariate analyses were applied to identify independent predictors of higher incidence of CVAs.

RESULTS

Forty-nine patients (1.0%) had a postoperative CVA, 24 early and 25 delayed, with a 30-day mortality of 34.7%. Independent CVA predictors were low output syndrome, presence of extracoronary vasculopathy, conversion from off to on pump, and any aortic manipulation. This latter risk factor was significant in patients with extracoronary vasculopathy, but not in patients without. Side-clamping was not a risk factor in patients operated on with CPB, but it was in no-CPB cases. Patients in group B1 had the same CVA incidence as patients in group A2. Therefore CPB, per se, was not a risk factor for higher CVA incidence.

CONCLUSIONS

Aortic manipulation must be avoided in patients with extracoronary vasculopathy. Maintenance of a good hemodynamic status is crucial for any patient to reduce CVA incidence. Patients with extracoronary vasculopathy are at higher risk, and a correct surgical strategy should be tailored for each case. In no-CPB cases use of side-clamping provides the same CVA risk as in patients in whom CPB, aortic cannulation, and cross-clamping were used.

Propofol and midazolam versus propofol alone for sedation following coronary artery bypass grafting: a randomized, placebo-controlled trial

The aim was to compare the efficacy and side-effects of propofol combined with a constant, low dose of midazolam versus propofol alone for sedation. In a prospective, randomized and double-blinded study, 60 male patients scheduled for elective coronary bypass grafting were enrolled. Postoperatively, patients were stratified to receive either a continuous intravenous infusion of midazolam 1 mg/h or placebo. Target Ramsay sedation score was 3 to 5 corresponding to conscious sedation. An intention-to-treat design for propofol was performed to reach target sedation. Efficacy of sedation was statistically significantly higher in the group midazolam + intention-to-treat with propofol compared with the group placebo + intention-to-treat with propofol (91% vs 79%; P=0.0005). Nine of 27 patients in the midazolam group (33.4%) and nine of 26 patients in the placebo group (34.6%) needed no supplementary propofol. Weaning time from mechanical ventilation was longer in the midazolam group whether or not they required supplemental propofol when compared with placebo group (all: 432 +/- 218 min vs 319 +/- 223 min; P=0.04; supplementary propofol: 424 +/- 234 min vs 265 +/- 175 min; P=0.03). The cumulative number of patients remaining intubated was significantly higher in the group midazolam + propofol compared with the group placebo + propofol (P=0.03). In conclusion, target sedation is reached slightly more often by the co-administration of propofol and a low dose of midazolam, but weaning time from mechanical ventilation is prolonged by the co-administration of propofol and a low dose of midazolam.

Carotid artery disease and stroke during coronary artery bypass: a critical review of the literature

OBJECTIVES

to determine the role of carotid artery disease in the pathophysiology of stroke after coronary artery bypass (CABG).

DESIGN

systematic review of the literature.

RESULTS

the risk of stroke after CABG was 2% and remained unchanged between 1970-2000. Two-thirds occurred after day 1 and 23% died. 91% of screened CABG patients had no significant carotid disease and had a <2% risk of peri-operative stroke. Stroke risk increased to 3% in predominantly asymptomatic patients with a unilateral 50-99% stenosis, 5% in those with bilateral 50-99% stenoses and 7-11% in patients with carotid occlusion. Significant predictive factors for post-CABG stroke included; (i) carotid bruit (OR 3.6, 95% CI 2.8-4.6), (ii) prior stroke/TIA (OR 3.6, 95% CI 2.7-4.9) and (iii) severe carotid stenosis/occlusion (OR 4.3, 95% CI 3.2-5.7). However, the systematic review indicated that 50% of stroke sufferers did not have significant carotid disease and 60% of territorial infarctions on CT scan/autopsy could not be attributed to carotid disease alone.

CONCLUSIONS

carotid disease is an important aetiological factor in the pathophysiology of post-CABG stroke. However, even assuming that prophylactic carotid endarterectomy carried no additional risk, it could only ever prevent about 40-50% of procedural strokes.

Atrial fibrillation after coronary surgery: comparison between different health care systems

AIMS

No studies have evaluated the influence of management strategies in different health insurance environments on atrial fibrillation (AF). This observational study compared the incidence of and treatment strategies for postoperative AF after primary coronary bypass surgery.

METHODS AND RESULTS

One insurance and one public funded location was compared: University of Michigan Health Center (USA, n=272) and Tampere University Hospital (Finland, n=314). USA patients had more co-morbidities and were treated more aggressively after acute myocardial infarction. More Finns were on beta-blockers both preoperatively (93 vs. 68%, P<0.001) and postoperatively (97 vs. 66%, P<0.001). However, AF was more frequent among Finns (38 vs. 29%, P=0.037) and present on 4.6% of cases when transferred postoperatively. No USA patients had AF at time of discharge. Mean length of stay was 8.6 days at USA, and not affected by AF. The incidence of in-hospital death, strokes and multiorgan failures was similar. Multivariable analysis, adjusted for site and selection biases (propensity analysis) revealed increasing age [OR=1.063 (1.042, 1.084), P<0.0001] and use of radial arteries [OR=2.175 (1.071, 4.417), P=0.032) to be independent predictors to the incidence of postoperative AF.

CONCLUSIONS

We found several major differences in patient selection and treatment strategies among primary coronary bypass patients managed in the two institutions. Despite the marked practice variation, the incidence of postoperative AF was rather similar. Despite routine use of beta-blockers, AF occurred in 29-38% of patients. However, the length of stay was not particularly affected by postoperative AF.

Surgical Approaches to Coronary Artery Disease

In this rapidly evolving era of coronary surgery, technologic advances have allowed the development of new myocardial revascularization strategies. Although conventional coronary artery bypass grafting is being challenged by other promising surgical procedures such as off-pump coronary artery bypass grafting, it remains the gold standard in patients with multivessel disease. Accurate evaluations of these new procedures are ongoing to assess their effectiveness and to define their role in the armamentarium of myocardial revascularization.

Alterations to haemostasis following cardiopulmonary bypass and the relationship of these changes to neurocognitive morbidity

Cardiopulmonary bypass (CPB) is routinely utilized to provide circulatory support during cardiac surgical procedures. The morbidity of CPB has been significantly reduced since its introduction 50 years ago; however, cerebral injury remains a potentially serious consequence of otherwise successful surgery. The risk of stroke postoperatively is approximately 1-5%. Incidence rates for neurocognitive deficit, however, vary markedly depending on the detection method, although typically it is reported in at least 50% of patients. The aetiology of this cerebral injury remains open to debate, although evidence shows that ischaemia secondary to microembolism may be the principal factor. Emboli originate from bubbles of air, atheroemboli released on aortic manipulation and thromboemboli generated as a result of haemostatic activation. Significant generation of thrombin occurs during CPB resulting in fibrin formation, although the trigger of this activation is not fully understood. Rather than originating from contact activation as previously thought, the primary trigger may be via the activated factor VII/tissue factor pathway of coagulation, with an additional role of contact activation in amplification of coagulation as well as the fibrinolytic response to CPB. Haemostatic activation is inhibited with systemic heparin therapy. The relationship between haemostatic activation and emboli formation during CPB is not known. Interventions to reduce cerebral injury in the context of cardiac surgery depend, in large part, on the minimization of emboli. This review investigates cerebral injury after cardiac surgery and evidence showing that microembolism is the principal causative agent. Fibrin emboli are postulated to be an important source of cerebral embolism. The mechanism of haemostatic activation during CPB is therefore also discussed.

On-pump and off-pump coronary artery bypass grafting in the elderly: predictors of adverse outcome

OBJECTIVE

To establish the role that coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB) may have in improving perioperative outcomes of patients 70 years of age and older.

BACKGROUND

Coronary revascularization in elderly patients is associated with morbidity and mortality rates higher than those observed in younger patients. The impact of CABG without CPB on perioperative outcomes has not been clearly established.

METHODS

This retrospective, nonrandomized study consisted of 1,872 CABG patients. Of these, 1389 underwent CABG with CPB (CPB group) and 483 patients underwent CABG without CPB (off-pump group). Preoperative variables and outcomes were compared between the two groups. Multivariate logistic regression analysis was used to identify independent predictors of mortality, stroke, and adverse outcome.

RESULTS

Demographics, Canadian Cardiovascular Society staging, operative priority, and other preoperative variables were comparable between the two groups. The prevalence of previous myocardial infarction was higher in the CPB group (62.6% vs 56.7%; p < 0.005), whereas the prevalence of calcified aorta and preoperative renal failure were higher in the off-pump group (5.4% vs 9.5%; p = 0.04 and 1.7% vs 3.3%; p = 0.04, respectively). Although the graft/patient ratio was higher in the CPB group (3.4 vs 1.9), these patients displayed more extensive coronary artery involvement. At univariate analysis, patients in the off-pump group had a higher rate of freedom from complications (88.2% vs 81.3%; p < 0.005) and a lower incidence of stroke (2.1% vs 4.2%; p = 0.034) than patients in the CPB group. Although there was a trend for a higher actual mortality in the off-pump group (4.8% vs 3.7%; p = ns), the risk adjusted mortality in this group was lower (1.9% vs 2.1%). Multivariate analysis showed that while the use of CPB correlated independently with an increased risk of overall complications, it was not associated with a higher probability of death or stroke.

CONCLUSIONS

This investigation suggests that elderly patients undergoing CABG may benefit from off-pump revascularization, as the use of CPB correlated independently with an increased risk of overall complications. However, CPB did not emerge as an independent predictor of death or stroke at multivariate analysis.

Stroke after cardiac surgery: short- and long-term outcomes

BACKGROUND

Stroke remains a devastating complication of cardiac surgery, but stroke prevention remains elusive. Evaluation of early and long-term clinical outcomes and brain-imaging findings may provide insight into stroke prognosis, etiology, and prevention.

METHODS

Five thousand nine hundred seventy-one cardiac surgery patients were prospectively studied for clinical evidence of stroke. Stroke and nonstroke patients were compared by early outcomes. Data collected for stroke patients included brain imaging results, long-term functional status, and survival. Outcome predictors were then determined.

RESULTS

Stroke was diagnosed in 214 (3.6%) patients. Brain imaging demonstrated acute infarction in 72%; embolic in 83%, and watershed in 24%. Survival for stroke patients was 67% at 1 year and 47% at 5 years. Independent predictors of survival were cerebral infarct type, creatinine elevation, cardiopulmonary bypass time, preoperative intensive care days, postoperative awakening time, and postoperative intensive care days. Long-term disability was moderate to severe in 69%.

CONCLUSIONS

Stroke after cardiac surgery has profound repercussions that are independently related to infarct type and clinical factors. These data are essential for clinical decision making and prognosis determination.

Off-pump coronary artery bypass grafting decreases risk-adjusted mortality and morbidity

BACKGROUND

The purpose of this study was to determine whether coronary artery bypass grafting without cardiopulmonary bypass (off-pump CABG) decreases risk-adjusted operative death and major complications after coronary artery bypass grafting in selected patients.

METHODS

Using The Society of Thoracic Surgeons (STS) National Adult Cardiac Surgery Database, procedural outcomes were compared for conventional and off-pump CABG procedures from January 1, 1998, through December 31, 1999. Mortality and major complications were examined, both as unadjusted rates and after adjusting for known base line patient risk factors.

RESULTS

A total of 126 experienced centers performed 118,140 total CABG procedures. The number of off-pump CABG cases was 11,717 cases (9.9% of total cases). The use of an off-pump procedure was associated with a decrease in risk-adjusted operative mortality from 2.9% with conventional CABG to 2.3% in the off-pump group (p < 0.001). The use of an off-pump procedure decreased the risk-adjusted major complication rate from 14.15% with conventional CABG to 10.62% in the off-pump group (p < 0.0001). Patients receiving off-pump procedures were less likely to die (adjusted odds ratio 0.81, 95% CI 0.70 to 0.91) and less likely to have major complications (adjusted odds ratio 0.77, 95% CI 0.72 to 0.82).

CONCLUSIONS

Off-pump CABG is associated with decreased mortality and morbidity after coronary artery bypass grafting. Off-pump CABG may prove superior to conventional CABG in appropriately selected patients.

Off-pump bypass grafting is safe in patients with left main coronary disease

BACKGROUND

Because of a concern about the ability to tolerate beating heart grafting, patients with left main coronary artery stenosis have been excluded from off-pump bypass. We reviewed our experience with off-pump coronary artery bypass grafting for patients with left main coronary artery disease.

METHODS

Eight hundred twenty-three patients underwent bypass grafting for left main coronary artery disease from January 1998 to October 1999. One hundred patients were revascularized without the use of cardiopulmonary bypass and compared with a contemporaneous cohort of 723 patients who underwent grafting with the aid of cardiopulmonary bypass. All patients had multivessel grafting performed through a sternotomy.

RESULTS

There was one death (1%) in the group undergoing off-pump grafting as compared with a 30-day mortality of 4.7% (p = 0.059) in the on-pump group. Univariate analysis established that patients revascularized without cardiopulmonary bypass were significantly less likely to require postoperative inotropic support (23% versus 62%, p < 0.001) and transfusion (35% versus 67%, p < 0.001). Logistic regression analysis revealed that cardiopulmonary bypass was an independent risk factor for mortality (odds ratio, 7.3; 95% confidence interval, 1.34 to 138.4).

CONCLUSIONS

Coronary artery bypass grafting using off-pump techniques are safe and effective in left main coronary artery disease.

Neurological injury after surgery for ischemic heart disease: risk factors, outcome and role of metabolic interventions

OBJECTIVES

Neurological complication remains a feared and increasing problem in association with cardiac surgery. The aim of this study was to analyze risk factors for neurological complications in a cohort of patients in whom inotropes for weaning from cardiopulmonary bypass was gradually replaced by metabolic treatment.

METHODS

The records of 775 consecutive patients undergoing coronary artery bypass grafting (CABG) or combined CABG+valve procedures were examined. Forward stepwise multiple logistic regression analysis was used for statistical evaluation of independent risk factors.

RESULTS

The incidence of neurological injury was 1.8% in patients undergoing isolated CABG and 5.4% after combined CABG+valve procedures. After cross-validation multivariate analysis identified history of cerebrovascular disease, advanced age and aortic cross-clamp time as independent risk factors for postoperative cerebral complications. Chronic obstructive pulmonary disease and number of bypasses also emerged as risk factors in the primary analysis.

CONCLUSIONS

In general, markers for advanced atherosclerosis, with history of cerebrovascular disease as the most important, emerged as predictors for neurological injury. Although it did not enter the final risk model, the results also suggest that postoperative heart failure deserves further surveillance as a potential risk factor for neurological complications. However, no evidence for untoward neurological effects associated with glutamate or glucose-insulin-potassium treatment was found.

Left hemispheric strokes in coronary surgery: implications for end-hole aortic cannulas

BACKGROUND

Perioperative stroke (POS) is a devastating complication of coronary artery bypass grafting (CABG). Many studies have been published concerning risk factors and possible causes of POS but none have studied which side of the brain is more frequently involved. The finding of a strong preponderance of left-sided strokes calls into question some widely held theories as to the cause of POS and implicates end-hole aortic perfusion catheters as a major factor.

METHODS

During a 3-year period (1996 to 1998), prospective data were collected on all 2,217 consecutive CABG patients at one hospital (with surgery by different surgeons in different groups). Strokes were classified as perioperative (within 3 days of surgery) or late (beyond 3 days but during hospitalization).

RESULTS

There were a total of 51 strokes (2.3%): 21 left, 10 right, 7 bilateral, 7 lacunar, 1 brainstem, and 5 indeterminate. There were 18 major territorial perioperative strokes on the left side and 6 on the right side. Thus, 75% (18 of 24) of POS were left-sided. Stroke patients were significantly younger than nonstroke patients (66.3 +/- 10.52 versus 71.4 +/- 8.47 years, p = 0.009). Other demographic data did not differ significantly.

CONCLUSIONS

If aortic clamping, cannulation, or manipulation were responsible for most strokes, then right-sided strokes should predominate, as the innominate artery is closest to the source of such emboli. In contrast, end-hole aortic cannulas direct a high-velocity jet at the left carotid orifice and may be responsible for a large proportion of POS. Side-hole aortic cannulas may reduce the incidence of this complication.

[Total arterial myocardial revascularization with both mammary arteries without extracorporeal circulation]

INTRODUCTION

Tector has described the off-pump total arterial revascularization technique, using multiple anastomosis with both internal thoracic arteries. To reduce surgical morbid-mortality, we have proposed the use of this technique without extracorporeal circulation.

PATIENTS AND METHODS

From April, 1998 the off-pump <<Tector>> technique was performed in 92 patients, 74 male (80%) and 18 female (20%), with a mean age of 64.9+/-8.1 years (42-78). Preoperative angiography demonstrated triple-vessel disease in 58 (63%) patients, and left main disease was present in 19 (20.5%) patients. Forty patients (43.5%) showed unstable angina, 24 patients (26%) significant peripheral vascular disease, and 26 (28%) diabetes mellitus. Both internal thoracic arteries were harvested using the skeletonization technique and were used like a <<T or T>> graft. The flow in the graft was measured using a flowmeter, and in 24 (26%) patients by angiographic study.

RESULTS

A total of 274 distal anastomoses were performed, 122 (44.6%) in the lateral or inferior wall, and 69 (25.2%) were sequential, with an average of 2.98 bypass/patient. In 59.8% of the patients a triple bypass was performed, 22% double bypass, 17% cuadruple bypass and 1 patient a quintuple bypass. During the initial six hours 64.9% of patients were extubated. Only one patient (1.1%) needed intraaortic ballon pumping and 3 (3.2%) inotropics during the postoperative course. Hospital mortality was 3 (3.2%) patients. Reoperation for bleeding was needed in just one patient (1.1%), and 78.3% of patients were not transfused. Mediastinitis occurred in 3 patients (3.2%). Postoperative stroke was not observed. At 7.7+/-2.8 months of mean follow-up all patients were free of symptoms and the global patency rate of 94%.

CONCLUSIONS

Off-pump Tector technique appears to be safe, offering a complete arterial revascularization and showing a reduction of surgical morbidity.