Xenon anaesthesia for patients undergoing off-pump coronary artery bypass graft surgery: a prospective randomized controlled pilot trial.

BACKGROUND: Off-pump coronary artery bypass (OPCAB) surgery carries a high risk for haemodynamic instability and perioperative organ injury. Favourable haemodynamic effects and organ-protective properties could render xenon an attractive anaesthetic for OPCAB surgery. The primary aim of this study was to assess whether xenon anaesthesia for OPCAB surgery is non-inferior to sevoflurane anaesthesia with regard to intraoperative vasopressor requirements. METHODS: Forty-two patients undergoing elective OPCAB surgery were enrolled in this prospective, single-blind, randomized controlled pilot trial. Patients were randomized to either xenon (50-60 vol%) or sevoflurane (1.1-1.4 vol%) anaesthesia. Primary outcome was intraoperative noradrenaline requirements necessary to achieve predefined haemodynamic goals. Secondary outcomes included safety variables such as the occurrence of adverse events (intraoperatively and during a 6-month follow-up after surgery) and the perioperative cardiorespiratory and inflammatory profile. RESULTS: Baseline and intraoperative data did not differ between groups. Xenon was non-inferior to sevoflurane, as xenon patients required significantly less noradrenaline intraoperatively to achieve the predefined haemodynamic goals {geometric mean 428 [95% confidence interval (CI) 312, 588] vs 1702 [1267, 2285] µg, P<0.0001}. No differences were found for safety. Significantly more sevoflurane patients developed postoperative delirium (POD) (hazard ratio 4.2, P=0.044). The average arterial pressure was lower in the sevoflurane group {median75 [interquartile range (IQR) 6] vs 72 [4] mmHg, P=0.002}. No differences were found for other haemodynamic parameters, the respiratory profile and the perioperative release of inflammatory cytokines, troponin T, serum protein S-100ß and erythropoietin. CONCLUSIONS: Compared with sevoflurane, xenon anaesthesia allows a significant reduction in vasopressor administration in OPCAB surgery. Moreover, xenon anaesthesia was associated with a lower risk for POD, a finding that has to be confirmed in larger studies. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT01757106) and EudraCT (2012-002316-12).

Cross-reactivity of a new food ingredient, dun pea, with legumes, and risk of anaphylaxis in legume allergic children.

BACKGROUND: Legume allergy is the fifth food allergy in Europe. The dun pea (Pisum sativum sativum var. arvense), a pea belonging to the same subspecies as green pea, has been recently introduced as an ingredient in the human food industry. The aims of this study were to evaluate the cross-reactivity between dun pea and other legumes and to search for modification of allergenicity induced by food technologies. METHODS: A series of 36 patients with legume and/or peanut allergy was studied. They underwent skin tests to peanut and a panel of legumes including dun pea. Specific IgE to dun pea and cross-reactivity to peanut allergens, particularly to Ara h 1, were evaluated by ELISA. Proteins and allergens of different pea extracts were studied by SDS-PAGE and immunoblots. RESULTS: In France and Belgium, 7.7% of severe food anaphylaxis cases were due to legumes. Patients with isolated legume allergy had positive prick tests to dun pea, whereas patients with isolated peanut allergy had negative prick tests. Cross-reactivity between sIgE to peanut and dun pea was observed, and more frequently than expected (96%) peanut-allergic patients with legume sensitization or allergy had sIgE to Ara h 1. Analysis of dun pea allergens suggested that protein epitopes were presented differently in dun pea seeds, isolate and flour. CONCLUSIONS: This study identifies, for the first time, a risk of dun pea allergy in legume-allergic patients and in a subset of peanut-allergic patients.

An apple a day ... chronic glossitis in a 4-year-old boy.

We report a case of chronic glossitis in a 4-year-old boy due to scurvy. The boy showed up in our department with a patchy depapillated tongue. A detailed dietary history revealed an unbalanced diet without any fruit or vegetable. The biological investigations showed a low serum ascorbic acid. The boy was treated by oral ascorbic acid during 15 days. The glossitis improved within one week and serum levels of vitamin C returned to the normal range. In industrial countries, scurvy became a rare disease in healthy children. However, since a few years, cases are reported in children and teenagers with unbalanced diet coming from economically favoured families. These extreme cases are one of the signs of a more general deterioration of dietary habits in paediatric populations in our societies. This emphasizes the importance of effective nutritional education programs aimed towards both parents and children.

The value of pulse pressure and stroke volume variation as predictors of fluid responsiveness during open chest surgery.

SUMMARY: We investigated the ability of pulse pressure variation and stroke volume variation to predict fluid responsiveness during mechanical ventilation in patients undergoing open chest surgery by comparing their respective correlations with cardiac output changes induced by leg elevation. Serial leg elevation manoeuvres were performed before and after sternotomy in 15 patients scheduled for elective off-pump coronary bypass surgery. Under closed chest conditions, both pulse pressure variation and stroke volume variation correlated well with the induced cardiac output changes (r = 0.856, p = 0.002 and r = 0.897, p = 0.0012, respectively). These correlations were lost for both parameters following sternotomy. Our data show that pulse pressure variation and stroke volume variation are valid predictors of fluid responsiveness under closed chest conditions but that this property no longer holds when the chest is open.

Assessment of myocardial viability in chronic coronary artery disease using technetium-99m sestamibi SPECT. Correlation with histologic and positron emission tomographic studies and functional follow-up.

OBJECTIVES: The value of 99mTc-sestamibi (2-methoxy-isobutyl isonitrile [MIBI]) as a viability tracer was investigated in patients undergoing coronary artery bypass graft surgery. BACKGROUND: Initial studies claim that rest MIBI single-photon emission computed tomographic (SPECT) studies can be used to assess myocardial viability. METHODS: Thirty patients with a severely stenosed left anterior descending coronary artery and wall motion abnormalities were prospectively included. The patients underwent a MIBI rest study, a positron emission tomographic (PET) flow (13NH3) and metabolism (18F-deoxyglucose) study and nuclear angiography before undergoing bypass surgery. A preoperative transmural biopsy specimen was taken from the left ventricular anterior wall. Morphometry was performed to assess percent fibrosis. After 3 months, radionuclide angiography was repeated. RESULTS: Statistically significant higher MIBI values were found in the group with myocardial viability as assessed by PET than in the group with PET-assessed nonviability (p < 0.01). Significantly higher MIBI values were found in the group with enhanced contractility at 3 months (76 +/- 13% vs. 53 +/- 22%, p < 0.01). A linear relation was found between MIBI uptake and percent fibrosis in the biopsy specimen (r = 0.78, p < 0.00001). When maximizing the threshold for assessment of viability with MIBI by using functional improvement as the reference standard, a cutoff value of 50% was found, with positive and negative predictive values of 82% and 78%, respectively. CONCLUSIONS: 99mTc MIBI uptake was significantly higher in PET-assessed viable areas and in regions with enhanced contractility at 3 months. A linear relation was found between percent fibrosis and MIBI uptake. An optimal threshold of 50% was found for prediction of functional recovery.

Is return of angina after coronary artery bypass grafting immutable, can it be delayed, and is it important?

BACKGROUND: Because survival after either an operation or angioplasty is similar across a wide spectrum of coronary patients, lasting symptom relief assumes high priority. OBJECTIVES: The objectives of this observational clinical study were (1) to determine whether the return of angina is immutable; (2) to identify factors that might delay its return, and (3) to evaluate whether its return is predictive of subsequent adverse events. METHODS: The return of angina of any degree of severity and morbid events subsequent to its return were studied by multivariable time-related analyses in a consecutive series of 9600 patients who were undergoing primary isolated coronary bypass operations between 1971 and 1992. RESULTS: The freedom rate from return of angina was 94%, 82%, 61% and 38% at 1, 5, 10, and 15 years. Increased modest risk of early return of angina was associated with preoperative demographic, symptom, coronary and vascular disease variables but reduced by more extensive arterial grafting. The ever-increasing risk of late return of angina was associated with demographic, symptomatic, left ventricular function, and coronary disease variables and was related strongly to comorbidity but was weakly reduced by controllable surgical variables. After the return of angina, 10-year freedom rate from infarct and survival was 71% and 68% respectively. CONCLUSIONS: (1) The risk of angina return increases relentlessly after operation, so it is likely immutable. (2) Delay of late angina return by use of arterial grafting is clinically trivial; control of noncardiac comorbidity may be more effective. (3) Fortunately, the return of angina after coronary artery bypass grafting has minimal impact on survival and is not predictive of imminent infarct.

Emergency coronary bypass grafting for evolving myocardial infarction. Effects on infarct size and left ventricular function.

Emergency aorta-coronary bypass grafting was performed early in the course of evolving myocardial infarction in 48 patients. The time interval between the onset of symptoms and reperfusion was 169 +/- 80 minutes. Quantitative assessment of postoperative thallium 201 myocardial scans in 19 patients revealed a significant salvage of myocardium after surgical reperfusion: The size of the residual infarction was less than 50% of that in a matched, medically treated, prospective control group (n = 39) (p less than 0.05). Postoperative equilibrium-gated radionuclide blood pool studies (technetium 99m) showed an enhanced recovery of regional and global ejection fraction after operation as compared to after medical treatment (p less than 0.05). Ultrastructural evaluation of biopsy specimens obtained during the operation delineated subendocardial necrosis in the majority of cases (72%), but subepicardial necrosis was found in only 6% of instances. Q-wave abnormalities were observed on the postoperative electrocardiogram in 50% of cases. Operative mortality was 0% in low-risk patients (i.e., hemodynamically stable condition, n = 26) and 18% in high-risk patients (i.e., cardiogenic shock including total electromechanical dysfunction, n = 22). Survival rate at 18 months was 92% +/- 4%, and 95% +/- 4% of the survivors were event free. It is concluded that early surgical reperfusion of evolving myocardial infarction limits infarct size significantly, enhances functional recovery, and may be a lifesaving operation in patients having cardiogenic shock associated with unsuccessful resuscitation.

Mechanical support with microaxial blood pumps for postcardiotomy left ventricular failure: can outcome be predicted?

OBJECTIVE: We sought to identify the indications of mechanical support in postcardiotomy left ventricular failure in patients who are unable to undergo transplantation. METHODS: From 1989 through 1997, 61 patients with postcardiotomy left ventricular failure beyond intra-aortic balloon pumping were assisted with the Hemopump cardiac assist system (Medtronic, Minneapolis, Minn). Their mean age was 64 +/- 8 years. Comorbidity was prevalent; 47% underwent cardiac massage before pump support, and evolving myocardial infarction was diagnosed in 43% before surgery. Multivariable logistic regression of data known at the moment of pump insertion was performed to identify the risk factors for mortality. RESULTS: Sixty-five percent of the patients were weaned from the device, but only 30% were discharged home. Cardiac index evolution during the first hours after pump insertion (P <.001) is the only independent predictor for possibility to wean from the device in the multivariable analysis. Acute renal failure is the only variable retained in the model for 90-day mortality. Device-related complications were far more frequent with the femoral (54%) than with the transthoracic (6%) cannula. Only 13% of the patients had bleeding complications. CONCLUSIONS: One third of the patients with postcardiotomy heart failure refractory to use of the intra-aortic balloon pump can be saved with the use of an endovascular axial flow pump. It is impossible to predict lethal outcome on preoperative data alone. The early hemodynamic response to support seems to be related to functional recovery of the heart and subsequent weaning from the device.

Nifedipine as an adjunct to St. Thomas' Hospital cardioplegia. A double-blind, placebo-controlled, randomized clinical trial.

The cardioprotective effect of the addition of the slow calcium-channel blocker nifedipine to cardioplegic solution was tested in two double-blind placebo controlled randomized studies. The first study included 24 patients undergoing aortic-coronary bypass grafting, and the second included 24 patients undergoing aortic valve replacement. Nifedipine at a dose of 200 micrograms/L or placebo was added to St. Thomas' Hospital cardioplegic solution. The following markers of ischemia were used: adenosine triphosphate and its catabolites, creatine phosphate and inorganic phosphate, determined in transmural left ventricular biopsy specimens taken before, at the end of, and after aortic cross-clamping; hemodynamic recovery 15 minutes after cessation of cardiopulmonary bypass; clinical outcome in terms of the incidence of arrhythmias, low cardiac output, positive inotropic support immediately after operation, and follow-up at 15 months. The main difference between the two studies was that myocardial temperature during cross-clamping remained constant at 14 degrees C in coronary bypass grafting but increased to 25 degrees C in valve operations despite the application of the same amounts of cardioplegic solutions. This lower temperature resulted in better preservation of high-energy phosphates in coronary bypass operations as compared to the placebo group having valve replacement operations. According to analysis of variance, a drug effect could be demonstrated only in the aortic valve replacement study: Accumulation of breakdown products of the adenine nucleotide pool was less in the nifedipine group than in the placebo group (p less than 0.05). Adenosine triphosphate decreased only to 84% in the nifedipine group and to 72% in the placebo group. Despite this adenosine triphosphate-sparing effect, weaning from cardiopulmonary bypass was more difficult in the nifedipine group. Left ventricular stroke work index 15 minutes after bypass was decreased to 72% of the prebypass value in the nifedipine group (t test, p less than 0.01) and only to 86% in the placebo group (p = NS). In contrast, after the patients were admitted to the intensive care unit, the incidence of low cardiac output tended to be lower in the nifedipine group than in the placebo group: 33% versus 58% (p = NS). In conclusion, ischemia-induced degradation of nucleotides as it occurs when myocardial cooling is inadequate can be prevented by the addition of nifedipine to the St. Thomas' Hospital cardioplegic solution. This effect, however, is not associated with an improved clinical outcome.

Intermittent aortic cross-clamping versus St. Thomas' Hospital cardioplegia in extensive aorta-coronary bypass grafting. A randomized clinical study.

Myocardial preservation was assessed in 72 patients undergoing extensive myocardial revascularization. The patients were allocated at random to three surgical techniques: Group 1, intermittent aortic cross-clamping at 32 degrees C; Group 2, intermittent aortic cross-clamping at 25 degrees C; and Group 3, St. Thomas' Hospital cardioplegia. As intraoperative markers of ischemic damage, adenosine triphosphate, creatine phosphate, and glycogen contents were determined in transmural left ventricular biopsy specimens taken at the beginning and at the end of cardiopulmonary bypass. Ultrastructure was studied in a similar pair of biopsy specimens. Release of myocardium-specific creatine kinase isoenzyme was determined intraoperatively and postoperatively. Functional recovery was assessed before and after weaning from cardiopulmonary bypass. The incidence of low cardiac output, myocardial infarction, and rhythm disturbances was compared between groups. Finally, actuarial survival and event-free curves were studied after 18 months' follow-up. The results show a better preservation of high-energy phosphates, glycogen, and ultrastructure in the cardioplegia group as compared to the two cross-clamp groups. However, severe myocardial damage was never observed. Release of MB creatine kinase isoenzyme was the same in all three groups. Functional recovery of the hearts immediately after cessation of cardiopulmonary bypass was better in the cardioplegia group, but the incidence of rhythm disturbances (atrioventricular conduction problems) was higher in the cardioplegia group than in the other two groups (p less than 0.05). Clinical outcome in terms of incidence of perioperative infarction, survival, and event-free follow-up was not different between groups. It is concluded that both techniques (aortic cross-clamping at 32 degrees C or 25 degrees C and St. Thomas' Hospital cardioplegia) offer good myocardial protection in extensive aorta-coronary bypass operations. St. Thomas' cardioplegia, however, in contrast to intermittent aortic cross-clamping, prevents the onset of ischemia-induced deterioration of cardiac metabolism, i.e., destruction of the adenine nucleotide pool.

Hemopump fails as bridge to transplantation in postinfarction ventricular septal defect.

From 1990, six patients were bridged to transplantation with a catheter-mounted axial flow pump (Hemopump). Indications were graft failure (two patients), postinfarction ventricular septal defect (two patients), myocarditis (1 patient), and myocardial infarction (1 patient). The 21F cannula, inserted via the groin, was used as a partial assist in four patients, and the 31F cannula, inserted via the ascending aorta, was used to assist the other two patients completely. Hemodynamic recovery was achieved in all patients (mean cardiac index rose from 2.1 L/gm/m2 to 3.85 L/gm/m2 after 1 hour assist). Sudden pump failure occurred in the two patients with postinfarction ventricular septal defect and a piece of necrotic tissue blocking the catheter was found. Both patients died. The other four patients were successfully bridged to transplantation. One of these patients died during his postoperative hospital stay; the three remaining patients were discharged and were well at follow-up (46, 40, and 3 months). The Hemopump device provides sufficient organ perfusion to be used as a bridge to transplantation. No conclusions can be drawn for the long-term use (longest run in this series was 102 hours). Postinfarction ventricular septal defect is a contraindication for the use of the Hemopump device.

Closing the loop: optimizing physicians' operational and strategic behavior.

Clinical databases are essential elements in optimizing medical care. They are no finality by themselves, but essential elements in the generation of knowledge. Optimal medical care starts with optimal care based on existing knowledge. This care continues with the registration of the variability in morbidity, comorbidity, and therapy, but also the registration of the early and late outcome. This should then allow the generation of structured inferences based on this registration and the closure of the loop, by treating patients according to this newly created evidence.

Does arterial revascularization decrease the risk of infarction after coronary artery bypass grafting?

BACKGROUND: This study sought to determine whether extensive arterial grafting reduces the prevalence and consequences of infarct after coronary artery bypass grafting. METHODS: Post-primary coronary artery bypass grafting infarcts and time-related events thereafter were identified by 99.9% complete follow-up of 9,600 patients (1971 to 1992). The contribution of arterial grafting to freedom from infarct was assessed by multivariable hazard function analysis to adjust for other risk factors. RESULTS: Unadjusted 1-month and 10-year freedom from infarction was 97% and 86%. By multivariable analysis, arterial grafting lowered the prevalence of periprocedural (p = 0.005), intermediate term (p = 0.007 and 0.006), and late infarction (arterial grafting to the left anterior descending coronary artery, p = 0.0006). Unadjusted survival after first infarct after coronary artery bypass grafting was 74% and 52% at 1 and 10 years; arterial grafting improved 10-year survival from 48% to 59% (p = 0.002). An additional benefit or cost of extending arterial grafting (n = 1,727) beyond a single one could not be identified (p > 0.1). CONCLUSIONS: Arterial conduits, particularly to the left anterior descending coronary artery, should be used for coronary artery bypass grafting to reduce early and late myocardial infarction and its consequences. However, use of more than a single arterial graft appears to confer no additional benefit.

Left ventricular assistance with the transthoracic 24F Hemopump for recovery of the failing heart.

BACKGROUND: The Hemopump was developed as a more powerful assist device for postcardiotomy support in patients in whom the intraaortic balloon pump is insufficient. METHODS: Over a 2-year period 21 (0.8%) of 2,585 patients undergoing cardiac operations needed a ventricular assist device because of postcardiotomy heart failure unresponsive to pharmacologic and intraaortic balloon support. Sixteen of these patients were assisted with the 24F transthoracic Hemopump left ventricular assist device. The aim of the mechanical support was myocardial recovery as the underlying conditions (age, arterial hypertension, diabetes, vascular and pulmonary disease) excluded heart transplantation. RESULTS: Hemodynamic improvement was apparent with a decrease in left atrial pressure (mean, 18.6 to 9.2 mm Hg), an increase in arterial blood pressure (mean, 54.1 to 70.1 mm Hg), and an increase in cardiac index. Five patients died within the first 24 hours because of low cardiac output. Although the heart was well unloaded (decrease in left atrial pressure of 8 +/- 4.69 mm Hg versus 9.3 +/- 5.51 mm Hg for the other patients), the increase in cardiac index was significantly lower (+0.516 versus +1.377 L.min-1.m-2; p = 0.027). Three of these 5 patients were known to have severe left ventricular hypertrophy. Of the remaining 11 patients, 2 were assisted for 1 week but failed to show recovery of the myocardium, 8 (50%) were weaned, and 4 (25%) were discharged. There were no device-related complications except the thrombosis of a cannula that was left for 10 days. CONCLUSIONS: The transthoracic Hemopump is an easy-to-use and reliable assist device. Left ventricular hypertrophy is a relative contraindication for the use of the Hemopump.

Determinants of early and late results of combined valve operations and coronary artery bypass grafting.

BACKGROUND: Factors determining the outcome of operative correction of valvular abnormalities combined with coronary artery bypass grafting are still incompletely defined. METHODS: Determinants of early and late (more than 90 days) deaths and event-free survival were studied for combined valve operations and coronary artery bypass grafting in 741 patients using multivariate analysis. RESULTS: Ninety-day survival probability was 89% (95% confidence interval, 87% to 92%). Preoperative risk factors for early death were age, female sex, renal failure, New York Heart Association class IV or V, and mitral insufficiency. The operative risk factor was the duration of aortic cross-clamping. Five- and 10-year survival probabilities were 74% (95% confidence interval, 71% to 78%) and 43% (95% confidence interval, 36% to 50%), respectively. Preoperative risk factors for late death were age, preoperative renal failure, New York Heart Association class IV or V, vessel disease, and nonsinus rhythm. Five- and 10-year event-free survival probabilities were 57% (95% confidence interval, 53% to 61%) and 23% (95% confidence interval, 17% to 28%), respectively. Preoperative risk factors for non-event-free survival were age, female sex, reduced left ventricular function, mitral regurgitation, and pacemaker rhythm. CONCLUSION: The demographic factors of age and female sex; the comorbid condition of renal failure; the cardiac conditions of advanced New York Heart Association class, left ventricular function, mitral regurgitation, vessel disease, and cardiac rhythm; and the operative condition of ischemia time are the most important predictors of clinical outcome after combined valve operations and coronary artery bypass grafting.

Left ventricular assist with an axial flow pump (Hemopump): clinical application.

Eighteen patients suffering from acute left heart failure were selected as candidates for Hemopump support. In 6 patients, peripheral atheromatosis prevented insertion of the device. Of the remaining 12 patients, 9 had postcardiotomy shock, 2 had acute rejection after orthotopic heart transplantation, and 1 had acute myocardial infarction complicated by a large postinfarction ventricular septal defect. During Hemopump support, hemodynamics recovered in all patients. Major complications were related to mechanical pump failure, such as fracture of the drive cable and expulsion of the cannula out of the ventricle, or to hemolysis of variable degree. Seven patients (58%) survived and were discharged from the hospital: the 2 patients bridged to heart transplantation and 5 of the 9 postcardiotomy patients, including 1 who could not be weaned but later underwent successful transplantation. The patient with the postinfarction ventricular septal defect died after removal of the device because of hemolysis. These results indicate that the Hemopump is a relatively noninvasive and efficacious left ventricular system of moderate power.

Mitral valve surgery combined with coronary bypass grafting: multivariate analysis of factors predicting early and late results.

Total of 123 patients (mean age: 63.8 +/- 7.3 years, (male/female 65/35 percent) underwent mitral valve surgery combined with coronary artery bypass grafting during a seven year period. Preoperatively 12% of them belonged to NYHA functional class II, 54% to class III, 29% to class IV and 3% was operated under emergency conditions. The mitral valve lesion was most frequently either ischaemic (45%) or rheumatic (33%) in origin. Left ventricle function was moderately decreased in 18% and severely damaged in 3% of the patients as documented by preoperative ventriculography. Coronary surgery was performed in all cases with an average number of distal anastomosis of 2.2 +/- 1.1 per patient. The hospital mortality was 13%. Risk factors for early and late mortality were determined by univariate and multivariate analysis. Advanced preoperative functional class and decreased left ventricular function or ischaemic etiology were identified as significant risk factors for early mortality. The patients were followed for an average of 33 +/- 25 months. The majority of them experienced significant functional improvement postoperatively with 69% belonging to NYHA class I or II. The late survival for the 107 hospital survivors was 94.7% at one year, and 84.7% at five years, respectively. Late survival was independently determined by preoperative functional class or previous myocardial infarction. Freedom from ischemic and valve related complications at five years was 95% and 71.2% respectively. 58.2% of the hospital survivors were in functional class I or II and free of any valve related or ischemic complications at the end of the fifth follow up year.(ABSTRACT TRUNCATED AT 250 WORDS)

Early and late outcome after CABG in patients with evolving myocardial infarction.

OBJECTIVE: To study the determinants of early and late outcome after coronary artery bypass grafting (CABG) for evolving myocardial infarction. METHOD: 269 consecutive patients underwent isolated primary or repeat CABG from 1971 to 1992 for evolving myocardial infarction. By institutional policy, these were patients, strictly diagnosed, infarcting either in the cardiac cateterization laboratory, shortly after a previous CABG, or on cardiac intervention waiting lists. At operation, 125 patients were hemodynamically stable, 89 patients in cardiogenic shock 55 patients in cardiopulmonary resuscitation (CPR). Interval between infarct onset and surgical reperfusion ranged from 53 min to 15 h (median, 135 min; 90% between 75 and 360). An internal mammary artery graft (IMA) was used in 81 patients. Cross-sectional follow-up was 100% complete and multivariable analysis was conducted in the hazard function domain. RESULT: One-month, 1-year and 10-year survival was 86, 84 and 66%, respectively. The 1-year and 10-year survival, stratified by hemodynamic class, was respectively 98 and 77% for the stable patients, 77 and 60% for the patients in shock and 62 and 49% for those undergoing CPR. Shock and CPR were incremental risk factors for early but not late risk. Use of an IMA graft was not a risk factor early or late in either stable or unstable patients. CONCLUSION: CABG can be performed with acceptable early and long-term risk in selected patients with evolving myocardial infarction, whatever their hemodynamic state. Outcome as regards survival is neither adversely or advantageously affected by choice of bypassing conduit. An evolving myocardial infarction with stable hemodynamics carries a lesser risk than an unstable anginal state with changing ST-segment.

Can the outcome of coronary bypass grafting be predicted reliably?

OBJECTIVE: To test prospectively the unsubstantiated claim that patient-specific predictions of time-related outcome after coronary artery bypass grafting (CABG) from multivariable parametric equations are reliable for medical decision making and for intra- and interdepartmental quality control in surgical training and practice. METHODS: 3720 survival curves were generated prospectively for all primary, isolated CABG patients operated upon at the Katholieke Universiteit (KU) Leuven between July, 1987 and January, 1992 using the published AHA/ACC guidelines multivariable equation derived from prior KU Leuven experience. The average of these curves (risk-adjusted predicted survival) was compared to the Kaplan-Meier (actual) estimates, overall and for patient subsets. Variables associated with systematic deviation of actual from predicted number of deaths were sought by multivariable residual risk analysis. RESULTS: Actual overall survival was less good than predicted (P = 0.03) and the excess risk was distributed uniformly across time. The excess risk was not attributable to substantial changes in prevalence of known risk factors. It was attributable largely to a small subset of patients (n = 292) with low-prevalence, but important risk factors not accounted for by the equation (P = 0.7, for difference in survival among the remaining 3428 patients). CONCLUSIONS: Within the confines of a single institution, patient-specific predictions of outcome after CABG can be made reliably in most patients using multivariable equations developed from a heterogeneous experience, despite changes in prevalence of risk factors. New subsets of high-risk patients, failure or inability to account for important rare risk factors or for institutional changes, may lead to systematic errors of prediction. Under these limitations it is an excellent tool for medical decision making and audit of surgical training and practice.

Validation and interdependence with patient-variables of the influence of procedural variables on early and late survival after CABG. K.U. Leuven Coronary Surgery Program.

OBJECTIVE: First to identify the patient-, procedural- and surgical experience variables influencing the early and late survival after CABG. Second to identify patients likely to benefit, and those unlikely to benefit, from technical details aimed at improving the results of coronary artery bypass grafting (CABG). METHODS: A consecutive series of 9600 patients who underwent CABG using a variety of revascularization methods between 1971 and 1992 were followed with 99.9% success. A multivariable time-related analysis was performed. Patient-specific predictions and nomograms were constructed from it to explore and validate the influences and interdependences of patient-variables with variations in details of the procedure. RESULTS: The 1-, 10- and 20-year risk-unadjusted survival was 97, 81 and 50% respectively. Patient-variables influencing early survival included severity of symptoms, patient presentation and extent of coronary disease, while late survival was influenced importantly by left ventricular function and cardiac and non-cardiac comorbidity. Technical details of the operation influencing early survival included use of endarterectomy, while details such as use of arterial grafting, extensiveness of sequential grafting, completeness of revascularization and extent of grafting to small coronaries influenced late survival to a highly variable degree. CONCLUSION: The early survival is neither improved nor worsened by single, multiple, sequential or complete arterial coronary reconstruction. The late survival is modestly improved with the use of an arterial graft to a major vessel, preferably but not exclusively to the anterior descendens, except for patients with limited life-expectancy. Differences in time-related survival with and without an arterial graft are nearly the same across all levels of ejection fraction. No late beneficial or detrimental effect was identified with more extensive use of arterial reconstructive surgery in multisystem disease.