Evaluation of 7,000+ patients with two different routes of cardioplegia

BACKGROUND: This study examined the efficacy and safety of retrograde cardioplegia in comparison with an antegrade/retrograde approach. METHODS: Between January 1, 1991, and December 31, 1995, 7,032 coronary artery bypass procedures, alone or in combination with valve replacement/repair, were performed using either retrograde cardioplegia (R) or an antegrade/retrograde (AR) approach. There were 4,224 patients in the R group and 2,808 in the AR group. These included elective, urgent, emergent/salvage, first operative, and redo cases. RESULTS: All preoperative, intraoperative, and postoperative variables listed in The Society of Thoracic Surgeons National Cardiac Surgery Database were used to compare the two groups using univariate analysis. The pump time was longer in the AR group, with fewer grafts per patient. The R group had higher predicted risk (3.2% versus 3.0%; p = 0.04), more postoperative atrial fibrillation (34% versus 31%; p = 0.006), and longer postoperative length of stay (8.8 versus 8.0 days; p < 0.001). Using The Society of Thoracic Surgeons National Cardiac Surgery Database predicted risk group model, a subgroup of 221 coronary artery bypass grafting patients in the retrograde (s-R) and 132 coronary artery bypass grafting patients in the antegrade/retrograde (s-AR) group fell into a greater incidence of predicted mortality group (> or = 10%). The s-R subgroup had more patients in New York Heart Association functional class IV. Univariate analysis revealed higher postoperative atrial fibrillation (51% versus 41%; p = 0.05) and longer postoperative length of stay (12.8 versus 10.8 days; p = 0.03) in the s-R subgroup versus the s-AR subgroup. CONCLUSIONS: The results appear to favor neither approach. Preoperatively, both retrograde groups (R and s-R) had higher preoperative predicted risk, but operative mortality or complications were not significantly increased when compared with the AR and s-AR groups. Retrograde cardioplegia alone was shown to be effective in the R and s-R groups, but atrial fibrillation developed in more patients, which could have contributed to longer length of stay in these groups. Antegrade/retrograde cardioplegia offers good immediate outcome but the delivery method can be cumbersome and confusing during the adjustments of flow clamps for antegrade/retrograde delivery and may contribute to prolonged pump times. From this retrospective, nonrandomized review, it appears that retrograde cardioplegia alone provides as good myocardial protection and safety as an antegrade/retrograde approach in either the low-risk or high-risk patient.     

Longterm followup (12-15 years) of a randomized controlled trial comparing Bassini-Stetten, Shouldice, and high ligation with narrowing of the internal ring for primary inguinal hernia repair

OBJECTIVE: To determine preoperative and perioperative risk factors for gastrointestinal (GI) complications following cardiac surgery. DESIGN: A database including records of patients who underwent cardiac surgery was reviewed, with univariate analysis of several variables thought to be relevant to GI complications. Using a risk-adjusted model, preoperative stratification was used to fit a logistic regression model including operative features. SETTING AND PATIENTS: All patients undergoing cardiac surgery from January 1, 1991, to December 31, 1994, at a university-affiliated teaching hospital. MAIN OUTCOME MEASURES: Incidence of GI complications, postoperative mortality, length of hospital stay, and relative risk of GI complications based on multivariate analyses. RESULTS: Gastrointestinal complications occurred in 2.1% of patients and had an associated mortality of 19.4%; this was higher than the mortality in patients without GI complications (4.1%; P < .001). Length of hospital stay was significantly longer in patients with GI complications (43 vs 13.4 days; P < .001). In patients who underwent coronary artery bypass grafting only, cardiopulmonary bypass time was significantly longer in patients with GI complications (166 vs 138 minutes; P = .004). In patients who underwent valve replacement, bypass time was not associated with GI complications. Use of a left internal mammary artery graft was associated with a lower incidence of GI complications. CONCLUSIONS: Patients who have GI complications after cardiac surgery have a higher mortality and a longer hospital stay. The use of a left internal mammary artery seems to have a protective effect against GI complications. Based on these observations, patients may be stratified into low-, medium-, and high-risk groups.     

The risk of coronary artery surgery in women: a matched comparison using preoperative severity of illness scoring

OBJECTIVE: To evaluate the effect of gender on outcomes of coronary artery bypass surgery using a weighted preoperative severity of illness scoring system. DESIGN: Retrospective database review. SETTING: Tertiary care teaching hospital. PARTICIPANTS: The patient population consisted of 2,800 consecutive coronary artery bypass graft (CABG) patients (658 women, 2,142 men), with or without concurrent procedures, operated on between January 1, 1993 and March 31, 1994. MEASUREMENTS AND MAIN RESULTS: Patients were stratified for severity of illness using a 13-element scoring system. The distribution of severity of illness scores and severity of illness-stratified morbidity, hospital mortality, and intensive care unit (ICU) length of stay were compared by chi-square and Fischer's exact test where appropriate. Median duration of intubation and median duration of ICU length of stay were examined by the median test. Female versus male unadjusted mortality (4.9% v 3.0%), total morbidity (15.0% v 9.2%), and average initial ICU length of stay (92.62% v 60.56 hours) were statistically different. Female patients also had significantly more of the following postoperative morbidities: central nervous system complications (focal neurologic deficits, patients > or = 65 years 3.20% v 1.54%; global neurologic deficits, patients > or = 65 years 2.75% v 1.25%), duration of perioperative ventilation that includes the intubation time in the operating room until extubation in the ICU (average = 77.36 hours v 49.20 hours; median = 21.87 v 20.26 hours), and average initial ICU length of stay (average = 92.62 hours v 60.56 hours; median = 42.33 hours v 27.91 hours). However, distribution of severity scores was also different. Women had significantly more preoperative risk factors (p < 0.05): age 65 to 74 years (45.1% v 36.6%), age > or = 75 years (21.3% v 11.9%), chronic obstructive pulmonary disease (10.8% v 6.4%), hematocrit less than 34% (21.9% v 5.5%), diabetes (34.8% v 21.8%), weight less than 65 kg (37.4% v 6.2%), and operative mitral valve insufficiency (9.6% v 6.0%). Stratified by severity, no statistically significant gender differences were found for mortality, morbidity, or ICU length of stay. CONCLUSIONS: Gender does not appear to be an independent risk factor for perioperative morbidity, mortality, or excessive ICU length of stay when patients are stratified by preoperative risk in this severity of illness scoring system.     

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.     

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.     

A national study of postoperative mortality associated with coronary artery bypass grafting in Israel. ISCAB Consortium. Israel Coronary Artery Bypass Study

BACKGROUND: Investigation of observed differences in outcomes among medical centers is of major interest to the medical community and the public and has a substantial impact on efforts to improve the quality of medical care. METHODS: This study analyzed data from consecutive patients who underwent isolated coronary artery bypass grafting at 14 medical centers. Data included demographic and clinical information, comorbidity, cardiac catheterization results, and 30-day postoperative vitality status. Logistic regression analysis was used to identify variables associated with mortality. An outlier hospital was defined as one having an observed mortality outside the 95% confidence interval boundaries around the expected mortality rate calculated, given the patient risk factors. RESULTS: The overall crude 30-day mortality rate for isolated coronary artery bypass grafting among the 4,835 patients in this study was 3.1%. The rate varied among centers, ranging from 0.85% to 7.05%. Predictors of 30-day mortality included advanced age, female sex, diabetes mellitus, poor left ventricular function, high creatinine level, high priority of operation, and three-vessel disease (with or without left main coronary artery disease). After adjustment for risk factors, two hospitals were defined as outliers. CONCLUSIONS: The observed disparity in early mortality among patients undergoing coronary artery bypass grafting is not due solely to differences in case mix.     

Ward versus intensive care management of high-risk surgical patients

BACKGROUND: Selection of high-risk surgical patients for preoperative and perioperative admission to an intensive therapy unit (ITU) for enhancement of oxygen delivery may reduce postoperative morbidity and mortality rates. Limited resources may prevent admission of all suitable patients. This audit study examined whether it is possible to select patients most at risk and thus reduce surgical morbidity and mortality rates when ITU services are limited. METHODS: This was a retrospective audit comparing the actual outcomes of complications and death with predicted outcomes using the POSSUM score (Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity) for 101 general surgical and vascular patients who would have fulfilled previously suggested criteria for preoperative admission to the ITU. Main outcome measures were the number of preoperative ITU admission criteria, American Society of Anesthesiologists (ASA) and POSSUM scores, preoperative oxygen delivery values, intravenous fluid therapy, length of ITU stay, length of hospital stay, postoperative complications and 28-day mortality. RESULTS: Medical staff allocated patients appropriately. There was a lower mortality rate than predicted from individual POSSUM scores. Patients who were admitted to the ITU before operation had the highest ASA scores, admission criteria and POSSUM scores; they also had significantly lower mortality and morbidity rates than predicted by the POSSUM scoring system. CONCLUSION: Patients with the greatest reduction in mortality and morbidity rates were admitted to the ITU before operation and had cardiovascular physiology 'optimized' before surgery.     

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.     

The unequal clinical profile, quality of life and hospital mortality in patients undergoing aortocoronary bypass in the public and private centers of Catalonia. The CIRCORCA Study

INTRODUCTION AND AIMS: The influence of the type of health care funding and management of hospital centres on hospital mortality in coronary artery bypass surgery (CABG) has not been analyzed in detail. We therefore assessed clinical and quality of life preoperative profiles and in-hospital mortality in public and private patients undergoing coronary bypass surgery in Catalonia. METHODS: Clinical questionnaires, Duke Activity Status Index (DASI) and SF-36 were preoperatively administered to all patients undergoing first coronary bypass surgery without associated procedures in Catalonia between November 1996-June 1997. In-hospital morbidity and mortality were recorded. RESULTS: Predictors of in-hospital death, including DASI, SF-36 and comorbidity scores, were significantly worse in public than in private patients. In-hospital mortality rate was more than ten times greater in public than in private patients (8.2% vs 0.7%; p < 0.001). Multivariate analysis identified private funding of health care, among others, as an independent predictor of in-hospital survival. Non evidence-based indications for surgery were significantly more common in private than in public patients (6% vs 0.7%, p < 0.001). CONCLUSIONS: a) In catalonia, the risk profile of public patients undergoing coronary bypass surgery was significantly higher than that of private patients, accounting, at least in part, for a remarkable mortality difference; b) non evidence-based indications for surgery were more common in private than in public patients; c) these unequal patterns raise questions about the adequacy of care and referral patterns in both private and public sectors.     

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.     

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.     

Drug therapy before coronary artery surgery: nitrates are independent predictors of mortality and beta-adrenergic blockers predict survival

We conducted this study to evaluate whether there is an association between preoperative drug therapy and in-hospital mortality in patients undergoing coronary artery graft surgery. We collected data on 1593 consecutive patients undergoing coronary artery surgery. The relative risk of in-hospital mortality was determined by logistic regression with in-hospital mortality as the dependent variable, and independent variables that included known risk factors and preoperative cardioactive or antithrombotic drug treatment, i.e., age; left ventricular function; left main coronary artery disease; urgent priority; gender; previous cardiac surgery; concurrent cardiovascular surgery; chronic lung disease; creatinine concentration; hemoglobin concentration; diabetes; hypertension; cerebrovascular disease; recent myocardial infarction; prior vascular surgery; number of arteries bypassed; and regular daily treatment with beta-blockers, aspirin within 5 days, calcium antagonists, angiotensin converting enzyme (ACE) inhibitors, digoxin, or warfarin. In-hospital mortality was 3.3%. The relative risk of in-hospital mortality (with 95% confidence intervals of the relative risk) associated with the following drug treatments was: nitrates 3.8 (1.5-9.6), beta-blockers 0.4 (0.2-0.8), aspirin within 5 days 1.0 (0.5-1.9), calcium antagonists 1.1 (0.6-2.1), ACE inhibitors 0.8 (0.4-1.5), digoxin 0.7 (0.2-1.8), and warfarin 0.3 (0.1-1.6). We conclude that in-hospital mortality is positively associated with preoperative nitrate therapy and negatively associated with beta-adrenergic blocker therapy. A significant association between in-hospital mortality and the preoperative use of calcium antagonists, ACE inhibitors, aspirin, digoxin, and warfarin was not confirmed. Implications: We examined the association between common drug treatments for ischemic heart disease and short-term survival after cardiac surgery using a statistical method to adjust for patients' preoperative medical condition. Death after surgery was more likely after nitrate therapy and less likely after beta-blocker therapy.     

Results of a regional study of modes of death associated with coronary artery bypass grafting. Northern New England Cardiovascular Disease Study Group

BACKGROUND: It is well known that surgeon-specific in-hospital mortality rates for coronary artery bypass grafting vary, but this aggregate measure does not suggest specific opportunities for improvement. METHODS: We performed a regional prospective study of 8,641 consecutive patients undergoing isolated coronary artery bypass grafting by all of the 23 cardiothoracic surgeons practicing in northern New England during the study period. Mode of death was assigned by an end points committee using predetermined definitions. Surgeons were ranked according to risk-adjusted mortality rates and grouped in terciles, and cause-specific mortality rates were determined. RESULTS: The mortality rate was 3.3% in the lowest surgeon mortality tercile and 5.8% in the highest tercile. Fatal heart failure accounted for 80.0% of the difference in aggregate mortality rates, ranging from 1.9% in lowest surgeon mortality tercile to 4.0% in the highest tercile (p < 0.001). Rates of other causes did not differ significantly across surgeon mortality terciles. Differences in rates of fatal heart failure could not be explained by differences in preoperative left ventricular dysfunction or other patient characteristics. CONCLUSIONS: Most of the difference in observed mortality rates across surgeons is attributable to differences in rates of heart failure.     

Extensive endarterectomy of the left anterior descending coronary artery combined with coronary artery bypass grafting

BACKGROUND: Complete revascularization of a diffusely diseased left anterior descending (LAD) coronary artery can be accomplished by extensive endarterectomy in conjunction with coronary artery bypass grafting (CABG). The present study was designed to assess the safety of the procedure, and which techniques lead to the best short- and long-term results. METHODS: Between January 1990 and October 1994 106 patients underwent extensive open endarterectomy of the LAD coronary artery combined with CABG at our institution. This group constituted 4.9% of all patients undergoing CABG during this period. The mean age of those studied was 64.4 +/- 9.2 years and 92% were male. In 22 patients (21%) the procedure was a repeat CABG and 12% had had percutaneous transluminal coronary angioplasty prior to the operation. Ninety-one per cent of the patients were in Canadian Cardiovascular Society (CCS) angina class 3 or 4, 91% had three-vessel disease and 36% had unstable angina at the time of surgery. The mean preoperative left ventricular ejection fraction was 53.6 +/- 14.9% (range, 15-80%). The internal mammary artery (IMA) was used to bypass the LAD coronary artery in 40 patients (38%) and a saphenous vein graft (SVG) was used in 66 patients. In 25 of the IMA bypass group an additional venous patch was used (IMA+P). RESULTS: The overall mortality rate was 9.4% (10 patients), including seven immediate postoperative deaths. When the IMA was used as a conduit the mortality rate was only 5.0%. There were seven (6.6%) postoperative non-fatal myocardial infarctions. There was a low incidence of other postoperative complications, similar to that following CABG without endarterectomy performed during the same period. Multivariate analysis identified emergency operation, two-vessel endarterectomy and female sex as independent risk factors for mortality. Upon follow-up study of 94 hospital survivors (98%), at a mean of 26.5 months (range, 1-48 months), all endarterectomy patients were in CCS class 1 or 2. Seventy-eight patients (83%) had an excellent postoperative exercise tolerance and the left ventricular function was preserved. The 4-year survival rates were 88% and 96% and the cardiac event-free survival rates were 74% and 87% in the SVG and IMA groups respectively. CONCLUSIONS: Complete revascularization of the diffusely diseased LAD coronary artery can be accomplished by adjunctive open endarterectomy with a degree of operative risk (mortality 9% and incidence of non-fatal myocardial infarction 7%). The immediate and medium-term results are improved when the IMA is used as a conduit, with or without additional venous patch. Independent risk factors for mortality were two-vessel endarterectomy, female sex and emergency operation. The long-term results revealed an overall survival rate of 92% and a cardiac event-free survival rate of 79% at 4 years, as well as excellent functional results.     

Modifying risk for extracorporeal circulation: trial of four antiinflammatory strategies

BACKGROUND: Despite recent rediscovery of beating heart cardiac surgical techniques, extracorporeal circulation remains appropriate for most heart operations. To minimize deleterious effects of cardiopulmonary bypass, antiinflammatory strategies have evolved. METHODS: Four state-of-the-art strategies were studied in a prospective, randomized, preoperatively risk stratified, 400-patient study comprising primary (n = 358), reoperative (n = 42), coronary (n = 307), valve (n = 27), ascending aortic (n = 9), and combined operations (n = 23). Groups were as follows: standard, roller pump, membrane oxygenator, methylprednisolone (n = 112); aprotinin, standard plus aprotinin (n = 109); leukocyte depletion, standard plus a leukocyte filtration strategy (n = 112); and heparin-bonded circuitry, centrifugal pumping with surface modification (n = 67). RESULTS: Analysis of variance, linear and logistic regression, and Pearson correlation were applied. Actual mortality (2.3%) was less than half the risk stratification predicted mortality (5.7%). The treatment strategies effectively attenuated markers of the inflammatory response to extracorporeal circulation. Compared with the other groups the heparin-bonded circuit had highly significantly decreased complement activation (p = 0.00001), leukocyte filtration blunted postpump leukocytosis (p = 0.043), and the aprotinin group had less fibrinolysis (p = 0.011). Primary end points, length of stay, and hospital charges, were positively correlated with operation type, age, pump time, body surface area, stroke, pulmonary sequelae, predicted risk for stroke, predicted risk for mortality, and risk strata/treatment group interaction (p = 0.0001). In low-risk patients, leukocyte filtration reduced length of stay by 1 day (p = 0.02) and mean charges by $2,000 to $6,000 (p = 0.05). For high-risk patients, aprotinin reduced mean length of stay up to 10 fewer days (p = 0.02) and mean charges by $6,000 to $48,000 (p = 0.0007). CONCLUSIONS: These pharmacologic and mechanical strategies significantly attenuated the inflammatory response to extracorporeal circulation. This translated variably into improved patient outcomes. The increased cost of treatment was offset for selected strategies through the added value of significantly reduced risk.     

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.     

Revascularization of the circumflex artery with mechanical stabilization: initial experience

OBJECTIVES: To evaluate the short-term result of the coronary artery revascularization without cardiopulmonary bypass for triple vessel disease, including the circumflex territory performed on the stabilized beating heart. METHODS: Prospective study conducted on the first 35 consecutive patients with triple vessel disease operated upon without cardiopulmonary bypass by a single surgeon (RC) at the Montreal Heart Institute between October 1996 and March 1997. RESULTS: Mean age of patients was 64 +/-1.6 years and the majority were men (30). Most common risk factors were hypercholesterolemia (65%) and familial history (55%) of ischemic heart disease. Main surgical indication was unstable angina (74%) and mean preoperative left ventricular ejection fraction was 53 +/- 3%. Hundred and twelve bypass were constructed averaging 3.2 +/- 0.1 grafts/patients of which 39 were made on branches of the circumflex artery. Average ischemic time was 34.17 +/- 2.17 minutes. The internal thoracic artery, saphenous vein, and radial artery were used as a vascular conduit in 44, 67, and 1 occasions respectively. There was one operative mortality, and one non Q perioperative myocardial infarction (CK-MB: 89 U/L). No patient required aortic counterpulsation balloon assistance. The average postoperative CK-MB (U/L) were 12.2 +/- 1.9, 15.2 +/- 3.2, and 10.3 +/- 1.7 at 1, 24 and 48 hours respectively. During the post-operative period 26% (9) of the patients presented atrial fibrillation, 6.5% (2) early reexploration for bleeding, and 63% (22) did not require transfusion. Average stay in hospital was 6.1 +/- 45 days. Coronary grafts were angiographically assessed in the first 10 patients and at the postmortem exam in one and displayed a 100% patency with 93.5% (29/31) adequate runoff. Conclusion: Triple vessel coronary artery disease revascularization is feasible on the beating heart without cardiopulmonary bypass with excellent short-term clinical and angiographic results.     

Surgical treatment of ischemic heart disease complicated with severe left ventricular dysfunction: experience in 200 cases

BACKGROUND: The study was designed to evaluate short and long-term benefits of coronary artery bypass graft in patients with coronary artery disease and severely depressed left ventricular ejection fraction and to identify contemporary risk factors associated with significantly greater mortality in this high-risk subgroup. METHODS: From 1985 to 1995, 200 consecutive pts with EF < or = 0.30 underwent CABG. Among these patients, 60% were older than 70 years. NYHA functional class III/IV was present in 31% of pts. Preoperative mean cardiac index was 2.7 +/- 7 l/min/m2, mean pulmonary artery pressure was 29.9 +/- 7 mm Hg and contractility score (generated by appropriate software for left ventricular kinesis analysis) mean value was 50.1 +/- 11.6 points. Urgent operation was required in 32 pts (16%). The majority of pts were completely revascularized. RESULTS: Operative mortality was 9% (18 pts). Low output syndrome was the most common postoperative complication (13.5%) followed by ventricular arrhythmia (8%), mean length of postoperative hospitalization for survivors was 13 +/- 10 days. Of 23 possible operative risk factors evaluated, four were associated with significantly greater mortality: cardiac index < or = 2.1 l/min/m2, urgent operation, contractility score > or = 80 and associated surgical procedures. Survivors experienced significant improvement in CHF class (p < 0.001) and follow up EF (p < 0.001). Kaplan-Meier estimate of survival at 1 year, 5 years and 8 years was 85%, 65% and 54%. CONCLUSION: Through more careful assessment of preoperative risk factors, patients selection and perioperative management, actually coronary artery bypass graft may be offered to pts with low ejection fraction with reduced morbidity and mortality.     

End-on aortogram: improved identification of important coronary artery anomalies in tetralogy of Fallot

OBJECTIVE: To identify coronary artery anomalies in patients with tetralogy of Fallot with an aortogram taken with steep caudal and left oblique angulation ("end-on" aortogram). DESIGN: Prospective evaluation of end-on aortogram in the preoperative angiographic assessment of consecutive patients with tetralogy of Fallot. SETTING: Regional paediatric cardiology centre. PATIENTS: 34 patients, aged 3 months to 12 years (median age 9 months). METHODS: An aortogram was performed with steep caudal (38 degrees-45 degrees) and left oblique (0 degrees-30 degrees) angulation under general anaesthetic as part of routine preoperative angiographic assessment. RESULTS: The origins and courses of the coronary arteries were visualised in all patients and important coronary artery anomalies were identified in four patients: single left coronary artery; single right coronary artery (two patients); separate high origin of left anterior descending. These anomalous coronary vessels crossed the right ventricular outflow tract. CONCLUSIONS: It is important to identify preoperatively coronary arteries that may interfere with right ventricular outflow tract reconstruction. An aortogram with steep caudal and left oblique angulation is useful in identifying anomalous coronary arteries and more importantly it defines the relation of these vessels to the right ventricular outflow tract.     

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.