Gastrointestinal complications after cardiac surgery

OBJECTIVE: Gastrointestinal (GI) complications after cardiac surgery with cardiopulmonary bypass (CPB) are uncommon complications with significant morbidity and mortality rates. METHODS: From 1988 to 1995, 36 GI complications were identified in 3158 patients who underwent cardiac surgery (1.14% incidence). The mortality rate was 13.9%. Complications included hemorrhage in the GI tract in 22, perforated ulcer in 3, acute cholecystitis in 3, pancreatitis in 2, mesenteric ischemia in 3, diverticulitis in 1 and liver failure in 2 patients. RESULTS: Clinical risk factors included advanced age, combined coronary artery bypass grafting (CABG)-valve operation, postoperative low cardiac output (LCO), prolonged ventilation time, re-exploration of the chest, sternal infection and a positive history of peptic ulcer. Patients with a prolonged pump time had an increased risk of GI complications (P < 0.001). CONCLUSIONS: Gastrointestinal complications, although of low incidence, carry a significantly high mortality, and the clinician must be alert to institute early appropriate treatment.     

Emergency coronary surgery after failed angioplasty: 11 years of experience (1987-1997)

METHODS: From January 1987 to December 1997, thirty patients underwent emergent or urgent coronary artery bypass grafting after failed elective percutaneous transluminal coronary angioplasty. Dissection/occlusion of the target artery was the commonest complication, but we also had two cases of stent dislocation and one case of coronary artery wall perforation. Two-thirds of the patients experienced extreme preoperatory hemodynamic instability (i.e., cardiac arrest or cardiogenic shock) and half had to be intubated in the Catheterization Laboratory. An average of 1.73 grafts/patient was performed. Complete coronary revascularization was achieved in 93% of the cases; the internal mammary artery could be employed in one-third only. RESULTS: In-hospital mortality was 10%, and perioperatory myocardial infarction or persistent ischemia could be detected in half of the patients. The need for aortic counterpulsation, and the use of inotropic and antiarrhythmic drugs were higher than average in this group of patients; while intensive care unit and hospital stay were longer. Patients with deteriorated preoperative hemodynamics fared significantly worse. Late results were encouraging: seventy-five per cent of all patients (and 84% of hospital survivors) were still alive an average of 52 months after surgery. Two-thirds of all patients (and 72% of hospital survivors) were alive and angina-free. CONCLUSIONS: Even in the current era, revascularization surgery after failed coronary angioplasty still carries an increased risk for postoperative complications and death, especially for patients with deteriorated preoperative hemodynamic conditions. On the other hand, postoperative middle- and long-term results are encouraging, as hospital survivors were similar to elective bypass patients regarding survival and freedom from return of angina.     

Factors influencing selected lengths of ICU stay for coronary artery bypass patients

This study examines factors influencing the length of intensive care unit stay for patients after coronary artery bypass surgery. Profiles of patients with selected lengths of ICU stay were identified for Group 1 (< or =1 day) and Group 2 (> or =2 days). Medical records of 175 patients who had undergone this procedure at an urban teaching hospital were reviewed. Patients who had a 1-day ICU length of stay were younger (mean=62.39, SD=10.88) and had comorbidities such as hypertension. Those patients with an ICU length of stay 2 days or longer were older (mean=68.18, SD=11.84) and had preoperative comorbidities such as congestive heart failure, chronic obstructive pulmonary disease, ejection fraction <50%, and need for an intra-aortic balloon pump. Atrial dysrhythmias, low cardiac output syndrome, renal insufficiency, and respiratory insufficiency were the postoperative complications associated with a prolonged ICU length of stay. Knowledge of the factors influencing selected lengths of ICU stay will enable nurses to choose patients for critical pathways and to anticipate postoperative problems in high-risk patients.     

Influence of ejection fraction on hospital mortality, morbidity, and costs for CABG patients

BACKGROUND: Preoperative ejection fraction (EF) has been shown to adversely affect postoperative hospital mortality and morbidity for patients undergoing isolated coronary artery bypass grafting. METHODS: To investigate influence of EF on isolated coronary artery bypass grafting outcomes (overall hospital mortality, hospital cardiac mortality, hospital morbidity, and hospital costs), data were reviewed from 1,354 consecutive patients who underwent isolated coronary artery bypass grafting between January 1, 1990, and April 30, 1992, at a single nonprofit hospital. Overall hospital mortality was 4.06% (cardiac, 2.36%). Hospital morbidity was 14.25% (including mortality). Hospital costs (not charges) averaged $16,673 per patient. To explore the impact of preoperative EF, EF was stratified into regular intervals. Each interval was then compared with regard to hospital mortality, morbidity, and average costs. A new statistical tool, discharge analysis, was developed to analyze the cost data. This was necessary because previous efforts at cost analysis have used tools inappropriate for real world cost data. RESULTS: The statistical analysis showed that patients with EF of 0.40 or greater had the best outcomes (lowest mortality, morbidity, and cost). Once the EF is 0.40 or greater the EF does not carry further predictive value. At EF less than 0.40, patients with EF less than 0.30 have a poorer outcome than patients with EF of 0.30 to 0.39. CONCLUSIONS: (1) Ejection fraction is a valid predictor of mortality, morbidity and resource utilization based on statistical analysis. (2) Patients can be broadly grouped as having EF greater than 0.40, less than 0.30, or from 0.30 to 0.39 with regard to clinical and cost outcomes. (3) Postoperative length of stay is not predicted by risk-adjusted EF. (4) A new tool, discharge analysis, is presented to facilitate cost analysis.     

Operative outcome and hospital cost

INTRODUCTION: Because of concern about increasing health care costs, we undertook a study to find patient risk factors associated with increased hospital costs and to evaluate the relationship between increased cost and in-hospital mortality and serious morbidity. METHODS: More than 100 patient variables were screened in 1221 patients undergoing cardiac procedures. Simultaneously, patient hospital costs were computed from the cost-to-charge ratio. Univariate and multivariate statistics were used to explore the relationship between hospital cost and patient outcomes, including operative death, in-hospital morbidity, and length of stay. RESULTS: The greatest costs were for 31 patients who did not survive operation ($74,466, 95% confidence interval $27,102 to $198,025), greater than the costs for 120 patients who had serious, nonfatal morbidity ($60,335, 95% confidence interval $28,381 to $130,897, p = 0.02) and those for 1070 patients who survived operation without complication ($31,459, 95% confidence interval $21,944 to $49,849, p = 0.001). Breakdown of the components of hospital costs in fatalities and in cases with nonfatal complications revealed that the greatest contributions were in anesthesia and operating room costs. Significant (by stepwise linear regression analysis) independent risks for increased hospital cost were as follows (in order of decreasing importance): (1) preoperative congestive heart failure, (2) serum creatinine level greater than 2.5 mg/dl, (3) New York state predicted mortality risk, (4), type of operation (coronary artery bypass grafting, valve, valve plus coronary artery bypass grafting, or other), (5) preoperative hematocrit, (6) need for reoperative procedure, (7) operative priority, and (8) sex. These risks were different than those for in-hospitality death or increased length of stay. Hospital cost correlated with length of stay (r = 0.63, p < 0.001), but there were many outliers at the high end of the hospital cost spectrum. CONCLUSIONS: We conclude that operative death is the most costly outcome; length of stay is an unreliable indicator of hospital cost, especially at the high end of the cost spectrum; risks of increased hospital cost are different than those for perioperative mortality or increased length of stay; and ventricular dysfunction in elderly patients undergoing urgent operations for other than coronary disease is associated with increased cost. Certain patient factors, such as preoperative anemia and congestive heart failure, are amenable to preoperative intervention to reduce costs, and a high-risk patient profile can serve as a target for cost-reduction strategies.     

Perioperative risk factors affecting hospital stay and hospital costs in open heart surgery for patients > or = 65 years old

OBJECTIVE: Demographic changes, associated with increased demands for open heart surgery in the elderly, place increased burden on financial resources. To evaluate perioperative risk factors affecting incidence of hospital events and estimation of hospital charges, 2577 patients > or = 65 years (range 65-91), operated on from January 1991 to December 1994, were compared with a concurrent cohort of 2642 younger patients. METHODS: Statistical analysis, by surgical procedure, focused on hospital mortality, key postoperative complications affecting length of hospital stay and hospital charges. RESULTS: Overall hospital mortality was 4.7%, 3.5% in younger patients versus 6.1% in the older group (P < 0.01). Mortality was significantly lower in patients less than 65 years undergoing coronary artery bypass grafting (3% versus 5%, P < 0.01) and valve replacement (4% versus 9%, P = 0.01). Significant risk factors for hospital death in the elderly: diabetes (P < 0.01), hypertension (P < 0.01), myocardial infarction (P < 0.01) and congestive heart failure (P < 0.01). Significant postoperative events, more common in older patients, included prolonged ventilation (P < 0.01), congestive heart failure (P < 0.01), infection (P < 0.01), cerebrovascular accident (P < 0.01), and intra aortic balloon pump (P < 0.01). Incremental risk factors for morbidity in the elderly were: higher New York Heart Association class, congestive heart failure, emergent operation, and female gender. Mean length of hospital stay for the < 65 group was 15.3 versus > 19.5 days for the > 65 group (P < 0.01). Length of stay over 18 days positively correlated with increased morbidity in both age groups. For patients > or = 65 years of age, the average hospital charge for open heart surgery was 172% higher for patients with a length of stay greater than 18 days compared with 165% for patients less than 65 years of age. CONCLUSIONS: Higher operative mortality and longer length of stay in elderly patients, resulting in increased health care costs, was associated with more co-morbidities. These results suggest interventions designed to reduce congestive heart failure and other co-morbidities may improve patient's recovery and reduce costs.     

Elimination of cardiopulmonary bypass: a prime goal in reoperative coronary artery bypass surgery

OBJECTIVE: The purpose of this study was to evaluate morbidity and mortality in reoperative coronary artery bypass surgery using the New York State database. METHODS: Patients undergoing reoperative coronary artery bypass between January-1995 and December 1996 were included. Patients were operated using cardiopulmonary bypass (CPB group, n = 184) or without cardiopulmonary bypass (non-CPB group, n = 105) by surgeon preference. Groups were compared for preoperative risk factors, postoperative mortality and major complications. RESULTS: Crude mortality was lower in the non-CPB group, despite a higher expected mortality, resulting in a risk-adjusted mortality of 1.3% versus 2.7% for the CPB group (NS). Of non-CPB patients, 91.4% were without complications, while only 72.1% of CPB patients (P < 0.0001) were complication-free. Major complications were significantly reduced in non-CPB patients compared to CPB patients: stroke 0% versus 3.8% (P < 0.04), cardiovascular complications 4.8% versus 15.8% (P < 0.005), other major complications 1.9% versus 10.4% (P < 0.007). Postoperative IABP support was needed in 1.9% of the non-CPB group patients and in 14.2% of the CPB group (P < 0.0007). CONCLUSIONS: The main object of reoperative CABG is to relieve symptoms, since the survival benefit of the procedure has not been demonstrated. Performance of reoperative coronary artery bypass surgery without cardiopulmonary bypass significantly reduces morbidity. We conclude that cardiopulmonary bypass should be avoided whenever possible in reoperative coronary bypass surgery.     

Improved outcome after coronary bypass surgery in patients with ischemic cardiomyopathy and residual myocardial viability

BACKGROUND: Although residual myocardial viability in patients with coronary artery disease and extensive regional asynergy is associated with improved ventricular function after coronary bypass surgery, the relationship between viability and clinical outcome after surgery is unclear. We hypothesized that patients with poor ventricular function and predominantly viable myocardium have a better outcome after bypass surgery compared with those with less viability. METHODS AND RESULTS: Seventy patients with multivessel coronary artery disease and left ventricular ejection fractions < 40% who underwent preoperative quantitative 201Tl scintigraphy before coronary bypass surgery were analyzed retrospectively. 201Tl scintigrams were reviewed blindly, and each segment was assigned a score based on defect magnitude. Segmental viability scores were summed and divided by the number of segments visualized to determine a viability index. The viability index was significantly related to 3-year survival free of cardiac event (cardiac death or heart transplant) after bypass surgery (P=.011) and was independent of age, ejection fraction, and number of diseased coronary vessels. Patients with greater viability (group 1; viability index > 0.67; n=33) were similar to patients with less viability (group 2; viability index < or = 0.67; n=37) with respect to age, comorbidities, and extent of coronary artery disease. There were 6 cardiac deaths and no heart transplants in group 1 patients and 15 cardiac deaths and two transplants in group 2 patients. Survival free of cardiac death or transplantation was significantly better in group 1 patients on Kaplan-Meier analysis (P=.018). CONCLUSIONS: We conclude that resting 201Tl scintigraphy may be useful in preoperative risk stratification for identification of patients more likely to benefit from surgical revascularization.     

Risk factors for postoperative morbidity

OBJECTIVE: Analysis of outcomes after coronary artery bypass grafting has focused on risk factors for operative mortality. Nonfatal perioperative morbidity is far more costly and more common after operation. To identify the risk factors that lead to postoperative morbidity, we evaluated 938 patients undergoing coronary artery bypass grafting at Albany Medical Center Hospital during 1993. METHODS: Multivariate statistical analysis was performed on preoperative patient variables to identify risk factors for either serious postoperative morbidity or increased hospital length of stay. Variables were considered both individually and in combination. For example, age was considered individually or in combination with other variables, including parameters of blood volume (i.e., age divided by red blood cell volume or Age/RBCVOL). Similar multivariate analysis was performed to identify independent risk factors for hospital mortality. RESULTS: In order of decreasing importance, the following patient variables were significantly associated with increased length of stay by stepwise Cox regression analysis: Age/RBCVOL, history of congestive heart failure, hypertension, femoral-popliteal peripheral vascular disease, chronic obstructive lung disease, and renal dysfunction. The combination variable, Age/RBCVOL, was an important risk factor for both increased length of stay and serious postoperative morbidity. Variables that were significant independent predictors of increased mortality, such as preoperative shock, and redo operation, were not risk factors for either serious morbidity or increased length of stay. CONCLUSIONS: We conclude that risk factors for postoperative morbidity are different from those for postoperative mortality. These results suggest that older patients with preoperative anemia and low blood volume who also have other comorbidities (congestive heart failure, stroke, chronic obstructive pulmonary disease, or hypertension) are at increased risk for postoperative complications. This allows identification of a high-risk cohort of patients who are likely candidates for interventions to lessen postoperative morbidity.     

Coronary artery bypass grafting in immune thrombocytopenic purpura

BACKGROUND: Reports of patients with idiopathic thrombocytopenic purpura undergoing cardiac operations are scarce and no recommendations exist regarding their management. We report 3 patients with idiopathic thrombocytopenic purpura and severe coronary artery disease who underwent uncomplicated coronary bypass grafting. METHODS: The case history of each patient with idiopathic thrombocytopenic purpura who underwent coronary artery bypass grafting and the literature were reviewed. RESULTS: All 3 patients underwent uncomplicated coronary artery bypass grafting after preoperative treatment with intravenous immunoglobulin and intraoperative platelet transfusions if needed. Prophylactic splenectomy was not performed. There was no increased incidence of bleeding complications. CONCLUSIONS: Coronary artery bypass grafting can be safely performed in patients with idiopathic thrombocytopenic purpura using conventional conduits after pretreating with immunoglobulin G and avoiding splenectomy.     

The C-terminal region of the Escherichia coli UvrC protein, which is homologous to the C-terminal region of the human ERCC1 protein, is involved in DNA binding and 5''-incision

STUDY OBJECTIVES: To examine the incidence and consequences of atrial arrhythmias in surgical ICU patients following major noncardiac, nonthoracic surgery. DESIGN: Prospective observational study. SETTING: University hospital surgical ICU. PATIENTS: Four hundred sixty-two consecutive patients after noncardiothoracic surgery. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Patients were assigned to one of three groups: group 1-new-onset atrial arrhythmias (n=47); group 2-history of atrial arrhythmias (n=58); and group 3-no atrial arrhythmias (n=357). New arrhythmias occurred in 10.2% of patients. Most began within the first 2 postoperative days. These patients had a higher mortality rate (23.4%), longer ICU stay (8.5+/-17.4 [SD] days), and extended hospital stay (23.3+/-23.6 days) than patients without atrial arrhythmias (mortality, 4.3%; ICU stay, 2.0+/-4.5 days; hospital stay; 13.3+/-17.7 days; p<0.02). Thirteen percent of patients had a history of atrial arrhythmias. They had a higher mortality rate (8.6%) and longer ICU stays (2.9+/-4.9 days; p<0.02) than patients without arrhythmias. Most deaths in the two arrhythmia groups were not due to cardiac problems, but to sepsis or cancer. CONCLUSIONS: Patients admitted to a surgical ICU after noncardiothoracic surgery with a history of or who developed new atrial arrhythmias had greater mortality and longer ICU stays than patients without arrhythmias. The incidence of new-onset arrhythmias was lower than reported after cardiac and thoracic surgery, but higher than in the general population. Atrial arrhythmias were not the cause of death and appear to be markers of increased mortality and morbidity.     

Abnormal left ventricular filling after neonatal repair of congenital heart disease: association with increased mortality and morbidity

BACKGROUND: The presence of mid-diastolic flow reversal on the mitral valve Doppler inflow indicates abnormal left ventricular filling. To determine whether mid-diastolic flow reversal predicts outcome in patients undergoing repair or palliation of neonatal congenital heart disease, we reviewed the echocardiograms and medical records of 40 patients with either left ventricular outflow obstruction or transposition of the great arteries. METHODS: All patients underwent surgical repair; transposition of the great arteries (TGA) = 17, coarctation of the aorta (CoA) = 14, interrupted aortic arch (IAA) = 8, and aortic stenosis (AS) = 1. The presence of mid-diastolic flow reversal was determined by pulsed Doppler interrogation of the mitral valve on preoperative and postoperative echocardiograms. RESULTS: Preoperative echocardiograms showed diastolic flow reversal in only 5 patients; 1 of 1 with AS and 4 of 14 with CoA. Twenty-one of 40 patients showed postoperative diastolic flow reversal; 1 of 1 with AS, 8 of 8 with IAA, 1 of 14 with CoA, and 11 of 17 with TGA. Postoperative mid-diastolic flow reversal 1 to 3 days after surgery was associated with higher mortality rate: 7 of 21 patients with diastolic flow reversal and 0 of 19 without diastolic flow reversal died. Patients with diastolic flow reversal who survived had longer intensive care unit (26.2 +/- 13.5 days vs 7.1 +/- 4.1 days, P <.001) and hospital (57.4 +/- 38.8 days vs 14.8 +/- 5.2 days, P <.05) stays. CONCLUSION: Mid-diastolic flow reversal is an indicator of prolonged hospital stay and mortality in patients with left ventricular outflow tract obstruction or TGA.     

Preoperative prediction of postoperative morbidity in coronary artery bypass grafting

BACKGROUND: The risk factors of patients selected for coronary artery bypass grafting have increased in recent years because of the aging population. Prediction of postoperative complications is essential for optimal use of the available resources. The aim of this study was to develop a scoring method for prediction of postoperative morbidity of individual patients undergoing bypass grafting. METHODS: Data from 386 consecutive patients who underwent coronary artery bypass grafting in a single center were retrospectively collected. The relationship between the preoperative risk factors and the postoperative morbidity was analyzed by the Bayesian approach. Three risk indices (15-factor and seven-factor computed and seven-factor manual models) were developed for the prediction of morbidity. The criterion for morbidity was a prolonged hospital stay postoperatively (> 12 days) because of adverse events. RESULTS: The best predictive preoperative factors for increased morbidity were emergency operation, diabetes, rhythm other than sinus rhythm on the electrocardiogram or recent myocardial infarction, low ejection fraction (< 0.49), age greater than 70 years, decreased renal function, chronic pulmonary disease, cerebrovascular disease, and obesity. The sensitivity of the scoring methods ranged from 51% to 72% and the specificity, from 77% to 86%. CONCLUSIONS: The results show that individual patients can be stratified according to postoperative risk for complications on the basis of preoperative information that is available for most patients.     

Mortality and morbidity among patients who undergo combined valve and coronary artery bypass surgery: early and late results

AIM: To describe mortality and morbidity early and late after combined valve surgery and coronary artery bypass grafting (CABG) as compared with CABG alone. PATIENTS and METHODS: All patients from western Sweden in whom CABG in combination with valve surgery or CABG alone was carried out in 1988-1991. RESULTS: Among 2116 patients who underwent CABG, 35 (2%) had this combined with mitral valve surgery and 134 (6%) had this combined with aortic valve surgery, whereas the remaining 92% underwent CABG alone. Patients who underwent combined valve surgery and CABG were older, included more women and had a higher prevalence of previous congestive heart failure and renal dysfunction but on the other hand a less severe coronary artery disease. Among patients who underwent mitral valve surgery in combination with CABG the mortality over the subsequent 5 years was 45%). The corresponding figure for patients who underwent aortic valve surgery in combination with CABG was 24%. Both were higher than for CABG alone (14%; P < 0.0001 and P = 0.003, respectively). In a stepwise multiple regression model mitral valve surgery in combination with CABG was found to be an independent significant predictor for death but aortic valve surgery in combination with CABG was not. Among patients who underwent mitral valve surgery in combination with CABG and were discharged alive from hospital 77% were rehospitalized during the 2 years following the operation as compared with 48% among patients who underwent aortic valve surgery in combination with CABG and 43% among patients with CABG alone. Multiple regression identified mitral valve surgery in combination with CABG as a significant independent predictor for rehospitalization but not aortic valve plus CABG. CONCLUSION: Among patients who either underwent CABG in combination with mitral valve surgery or aortic valve surgery or CABG alone, mitral valve surgery in combination with CABG was independently associated with death and rehospitalization, but the combination of aortic valve surgery and CABG was not.     

Central venous catheter use in low-risk coronary artery bypass grafting

BACKGROUND: To assess the impact of central venous pressure catheter monitoring in low-risk coronary artery bypass grafting (CABG), we compared the hospital course of patients undergoing CABG with central venous pressure catheter monitoring with that of similar patients undergoing CABG with pulmonary artery catheter monitoring. METHODS: All isolated primary CABG procedures (n = 312) performed between April 22 and October 31, 1996, were evaluated, and 194 patients meeting six central venous pressure catheter use criteria were identified. Of these 194 patients, 133 (68%) underwent CABG with central venous pressure catheter monitoring, and 61 (32%) had pulmonary artery catheter monitoring owing to surgeon or anesthesiologist preference. RESULTS: In-hospital mortality was similar. A trend toward increased overall complications was seen in the pulmonary artery catheter group. The total volume infused in the first 12 hours, the 24-hour weight gain, and the intubation time were significantly greater in the pulmonary artery catheter group. Increases in intensive care unit length of stay and in total hospital charges trended toward statistical significance in the pulmonary artery catheter group. CONCLUSIONS: Pulmonary artery catheter use in low-risk patients undergoing CABG was associated with greater weight gain and longer intubation time and may be associated with increased morbidity and utilization of hospital resources.     

Selection of patients for cardiac evaluation before peripheral vascular operations

PURPOSE: This study evaluated the value of preoperative cardiac screening with dipyridamole thallium scintigraphy and radionuclide ventriculography in vascular surgery patients. METHODS: From July 1, 1989, to Dec. 31, 1991, we routinely (irrespective of the patient's cardiac history or symptomatology) performed dipyridamole thallium scintigraphy (DTS) and radionuclide ventriculography (RVG) in 394 patients being considered for an elective vascular operation. Patients with reversible defects on DTS underwent coronary arteriography. RESULTS: DTS results were normal in 146 patients (37%), showed a fixed defect in 75 (19%), and showed a reversible defect in 173 (44%). Patients with and without a history of angina or myocardial infarction had identical rates of reversible defects. Normal left ventricular function (> 50%) was noted in 76% of the patients; 17% had moderate dysfunction (35% to 50%) and 7% had a low ejection fraction (< 35%). The finding of severe coronary artery disease led to cardiac revascularization in 17 patients who had no prior history of cardiac disease and in 13 patients with a history of angina or myocardial infarction. Two deaths and nine major complications were associated with coronary arteriography and cardiac revascularization. Vascular procedures (144 aortic, 53 carotid, 146 infrainguinal) were ultimately performed in 343 patients, with a mortality rate of 1.7% (3.5% aortic, 0% carotid, and 0.7% infrainguinal bypass). The nonfatal perioperative myocardial infarction rate was 2.0%. We monitored all 394 patients for cardiovascular events, with a mean follow-up of 40 months. Patients who underwent cardiac revascularization had a 4-year survival rate of 75%, which was similar to those with a normal DTS. Late cardiac events were significantly more frequent in patients who had either a reversible DTS or RVG < 35%. CONCLUSIONS: Routine cardiac screening of vascular surgery patients had similar impact on patients irrespective of their prior history or current symptoms suggesting coronary artery disease. Routine screening did not result in substantial benefit. Screening studies such as DTS or RVG may be most useful as part of an overall risk versus benefit assessment in patients without active symptoms of coronary artery disease who have less compelling indications for vascular intervention (claudication, moderate-sized aortic aneurysms, or asymptomatic carotid disease).     

Risk factors for stroke after cardiac surgery: Buffalo Cardiac-Cerebral Study Group

PURPOSE: The purpose of this study was to identify risk factors for stroke in patients undergoing heart surgery. METHODS: A retrospective chart review of patients who underwent cardiac surgery in three hospitals of the State University of New York at Buffalo system over a 36-month period was completed. Demographics and risk factors were recorded, and stroke and death were determined by chart review. Carotid artery stenosis was determined by duplex examination. Data were analyzed by chi-squared and multiple logistic regression. RESULTS: One thousand one hundred seventy-nine cases were analyzed, with a mortality rate of 2.3%, stroke rate of 1.6%, and combined stroke/death rate of 3.1%. Four variables were found to be associated with an increased risk of stroke: carotid artery stenosis greater than 50%, redo heart surgery, valve surgery, and prior stroke. Five variables were associated with increased mortality rates:; carotid artery stenosis greater than 50%, redo surgery, peripheral vascular disease, longer pump time, and hypercholesterolemia. Carotid artery stenosis greater than 50% was present in 14.7% of cases. Carotid artery stenosis greater than 75% was not itself associated with increased stroke risk. Most strokes occurred more than 24 hours after surgery. Stroke distribution did not correlate with site of carotid artery stenosis greater than 50%. CONCLUSIONS: Most neurologic events after heart surgery occur in a subset of patients who can be defined before operation. Whereas carotid artery stenosis greater than 50% is a strong risk factor, the role of prophylactic endarterectomy is unclear. Future studies should focus on this high-risk subgroup. A prospective study of prophylactic carotid endarterectomy in patients undergoing coronary artery bypass grafting is needed.     

Atrial fibrillation after bypass surgery: does the arrhythmia or the characteristics of the patients prolong hospital stay?

STUDY OBJECTIVES: The goal of this study was to determine whether prolonged hospital stay associated with atrial fibrillation or flutter (AF) after coronary artery bypass graft (CABG) surgery is attributable to the characteristics of patients who develop this arrhythmia or to the rhythm disturbance itself. DESIGN: An investigation was conducted through a prospective case series. SETTING: Patients were from a single urban teaching hospital. PARTICIPANTS: Consecutive patients undergoing isolated CABG surgery between December 1994 and May 1996 were included in the study. INTERVENTIONS: No interventions were involved. RESULTS: Of 436 patients undergoing isolated CABG surgery, 101 (23%) developed AF. AF patients were older and more likely to have obstructive lung disease than patients without AF, but both patients with and without AF had similar left ventricular function and extent of coronary disease. ICU and hospital stays were longer in patients with AF. Multivariate analysis, adjusted for age, gender, and race, demonstrated that postoperative hospital stay was 9.2+/-5.3 days in patients with AF and 6.4+/-5.3 days in patients without AF (p<0.001). CONCLUSIONS: Although AF is strongly associated with advanced age, most of the prolonged hospital stay appears to be attributable to the rhythm itself and not to patient characteristics.     

5-year reoperation rates after different types of lumbar spine surgery

STUDY DESIGN: Population-based cohort study of Washington State patients who underwent lumbar spine surgery for degenerative conditions in 1988. OBJECTIVES: To compare complications and reoperation rates during the 5-year period after surgery between patients who have undergone lumbar spine fusion surgery and those who have undergone laminectomy or discectomy alone. SUMMARY OF BACKGROUND DATA: Spinal fusion is associated with wider surgical exposure, more extensive dissection, and longer operative times than lumbar surgery without fusion, and previous studies have shown higher complication rates and hospital charges associated with these more complex procedures. In elderly patients, spinal fusion operations were associated with higher mortality rates than laminectomy or discectomy alone, and reoperation rates were not lower. In the current study, reoperations, mortality, and complications following lumbar spine surgery were examined for the general population. METHODS: A statewide hospital discharge database was used to identify all Washington patients who underwent spine surgery in 1988 and to determine the rate of reoperation during the subsequent 5 years. Administrative records also were used to identify complications, mortality, and hospital charges associated with the operations. Unadjusted complication and reoperation rates for the groups were compared using chi-square statistics. Adjusted rates were compared using logistic regression and proportional hazards (Cox) regression after controlling for age, gender, prior spine surgery, diagnosis, comorbidity, type of surgery, and coverage by Workers' Compensation. RESULTS: Of 6376 patients who underwent lumbar surgery for degenerative conditions in Washington in 1988, 1041 (16%) had operations involving spine fusion. Diagnoses of degenerative disc disease or possible instability were more frequent among patients undergoing fusion surgery, whereas herniated discs were more frequent among those undergoing discectomy or laminectomy alone. Complications were recorded in 18% of fusion patients and 7% of nonfusion patients (P < 0.01), but mortality rates did not differ. Unadjusted reoperation rates over the 5-year period were greater for patients who underwent fusion than for patients who underwent nonfusion surgery (18% vs. 15%, respectively), but after adjustment for baseline characteristics, fusion patients had only a slightly greater (and nonsignificant) risk of reoperation (relative risk 1.1, confidence interval .9-1.3). CONCLUSION: As in previous studies, complications in the current study occurred more frequently among patients who underwent lumbar spine fusion than among those who underwent laminectomy or discectomy alone. Reoperations were at least as frequent after fusion, but the authors could not assess treatment efficacy in terms of pain relief or improved function. Although the characteristics of patients undergoing fusion differed from those undergoing a laminectomy or discectomy alone, there appeared to be sufficient overlap in the clinical populations to warrant closer scrutiny of the safety, efficacy, and indications for spinal fusions, preferably in randomized trials.     

Unique retina cell phenotypes revealed by immunological analysis of recoverin expression in rat retina cells

OBJECTIVE: This study was undertaken to determine the impact of previous cardiac surgery on the presentation, management, and outcome of late dissection of the ascending aorta. PATIENTS AND METHODS: From 1976 to 1998, type A dissection developed in 56 patients with a history of previous cardiac surgery. Interval from first operation to type A dissection was 49 +/- 47 months (0.3-180 months). Previous operations were coronary artery bypass grafting (n = 40), aortic valve replacement (n = 8), and other (n = 8). RESULTS: Type A dissection was acute in 34 patients and chronic in 22. In acute dissection, aortic insufficiency occurred in 50%, malperfusion in 12%, and rupture in 18%; 2 patients (6%) were in hemodynamically unstable condition because of rupture. Of patients with previous coronary bypass grafting, 98% had preoperative coronary angiography. Type A dissection was treated by supracoronary tube graft (84%), Bentall procedure (14%), or local repair (2%). Strategies for managing previous coronary bypass grafting included reimplantation of proximal anastomoses with a button of native aorta (29 patients), interposition graft to pre-existing saphenous vein grafts (9 patients), and new saphenous vein grafts (20 patients). Eight hospital deaths occurred (14%). CONCLUSIONS: We conclude that (1) patients having type A dissection late after cardiac surgery infrequently have cardiac tamponade and hemodynamic collapse; (2) patients with previous coronary bypass grafting require coronary angiography, because operative management must account for pre-existing coronary artery disease; and (3) operative mortality is low, and this may be attributable to preoperative hemodynamic stability, delineation of coronary anatomy in those with previous coronary bypass grafting, and operative treatment of coronary artery disease.