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Biomedical subjects

P Sergeant

Publications and source records attributed to P Sergeant.

At least 19 recordsLinked to original sources
PubMed2001

The challenge of departmental quality control in the reengineering towards off-pump coronary artery bypass grafting.

OBJECTIVE: Off pump coronary surgery is a major reengineering effort of the surgical systems. There are no perfect tools available to guide every centre in the confrontation with the complete spectrum of risk and the limited number of events. This study analyses the use of a hospital mortality risk-stratifying system in the complete shift towards off-pump CABG. METHODS: All 535 off-pump CABG patients from January 1997 till September 2000 underwent a comparison of their hospital mortality versus the EuroSCORE predictions. The mean risk predicted by the EuroSCORE was 4.5+/-3% (range 0-14) and the mean age was 65+/-10 years (range 36-89). The series includes 23 repeat procedures, also 77 patients with per oral or insulin-treated diabetes. The number of distal anastomoses was 2.5+/-1 and of arterial grafts 1.3+/-0.6. RESULTS: The observed hospital mortality was 15 patients, 2.8% (Fisher exact test P=0.19 versus the EuroSCORE). The 1 and 3 month Kaplan-Meier survival, irrespective from hospital discharge, was 97.4+/-0.7 and 97.2+/-0.7%, respectively. A cumulative risk-adjusted mortality plot is constructed. The area under the ROC curve was 0.886. A stepwise sampling of patients according to increasing risk identified the difference between the EuroSCORE-predicted and observed hospital mortality for the complete spectrum of risk. The P value of this difference was 0.06 for the grouping including all patients from 0-5% risk (78% reduction), 0.04 for the grouping 0-8% risk (61% reduction), and 0.05 for the grouping 0-11% risk (52% reduction of risk). The loss of statistical significant difference was due to the inclusion of the patients at extremely high risk. CONCLUSION: A hospital mortality risk-stratifying system can provide guidance but different and in depth approaches are mandatory to improve the insight, certainly in the presence of a large spectrum of risk.

Aged↗
PubMed2001

Single centre, single domain validation of the EuroSCORE on a consecutive sample of primary and repeat CABG.

OBJECTIVES: Intra- and interdepartmental benchmarking require scoring systems with excellent performance on several properties: discrimination (resolution), reliability (calibration) and stability over the complete spectrum of peri-procedural risk. This single centre, single domain study validates the European system for cardiac operative risk evaluation (EuroSCORE) on an independent sample of primary and repeat coronary artery bypass grafting (CABG) patients and will evaluate these different properties. METHODS: The study population is a consecutive series of 2051 isolated primary and repeat CABG patients, inclusive of patients in cardiogenic shock or resuscitation, operated on in a single institution from January 1997 to July 2000. The age of the patients was 66+/-9 years, 77% were males and 7% were repeat procedures. The EuroSCORE was 5.0+/-3%, with a range from 0 to 22. The studied event was in-hospital death, defined as mortality during hospital stay, which was unlimited in time and included a stay in a secondary hospital without discharge home. RESULTS: The EuroSCORE predicted 102 deaths versus 81 deaths observed (P=0.14, Fisher exact test). The EuroSCORE described only 20% of the variance of in-hospital mortality. The EuroSCORE created an area under the receiver operating characteristic curve of 0.83+/-0.03. The highest discriminative accuracy was obtained with 8% EuroSCORE risk (only 64% sensitivity and 87% specificity). Further exploration identified an over score in the EuroSCORE range 0-8 (57%, P<0.0001). There was an equal score (-2%, P=1) in the range 9-11, but an under score in the range 12-22 (-133%, P=0.003). CONCLUSIONS: On the condition that these single centre results could be extended to any European cardiac surgery centre, it can be concluded that the overall acceptable performance of the EuroSCORE is the result of an over score in the lower risk and insufficient correction in the higher risk spectrum. The EuroSCORE is probably refined enough for improved informed consent versus aggregated results but should only be used for inter-institutional benchmarking with great caution, preferably below the 12% risk pivot.

Aged↗
PubMed2001

[Towards simplified cesarean section?].

In the past few years, many international publications have reported important improvements in the cesarean section procedure. Considering these improvements, M STARK suggests a new technique for the cesarean section which is called < > (=ML). To assess feasibility and efficiency of this technique the authors conducted a prospective randomised study for 4 months including all cesarean sections and compared the ML technique with the classical Pfannenstiel are. The following criteria were noted for each woman. Results showed the superiority of the M.L. technique especially with regard to the length of duration of the post-operative fever and the parietal blood collection, where difference is significant. Regarding the blood loss rate, the post-operation pain, the delay before gas and the duration of the hospitalisation period the M.L. technique seems to be better although the difference is not very significant statistically. Following this study and the international literature survey, authors conclude that the M. L technique is so much better than the pfannenstiel technique that it must be used throughout daily obstetrical practice.

Blood Loss, Surgical↗
PubMed2000

Micropumps to support the heart during CABG.

OBJECTIVE: To show the effect of myocardial support by micropumps during beating heart CABG for triple vessel disease. METHODS: In 12 sheep, three coronary arteries (LAD, intermediate branch and circumflex) were consecutively occluded for 10 min. The animals were divided in two groups: group 1 without support (n=6) and group 2 with biventricular support of intravascular micropumps. The pumps (diameter 6.4 mm) were placed through peripheral access (femoral artery and jugular vein) and advanced under fluoroscopic guidance. The hemodynamic evolution was analyzed during the procedure and 2 h of reperfusion. Myocardial flow was assessed by colored microspheres. Differences between groups were analyzed by ANOVA for repeated measurements and post-hoc testing in case of significance. RESULTS: All of the pump-supported animals survived the procedure, 1 of the control animals died of resistant ventricular fibrillation. At the end of the reperfusion period, the hemodynamic performance and myocardial contractility was significantly better in the pump-supported group (cardiac output: 2.4+/-0.9 vs. 3.3+/-0.9 l/min, P=0.0192; mean arterial blood pressure: 51+/-23 vs. 73+/-9 mmHg, P=0. 036; first derivative of the left ventricular pressure: 561+/-271 vs. 947+/-316 mmHg/s, P=0.0074). After the procedure, subendocardial blood flow was significantly better in all areas of the left ventricle in group 2 (0.935+/-0.427 ml/min per g vs. 0.409+/-0.183 ml/min per g in group 1; P=0.0366). CONCLUSION: The supported heart is more resistant to repetitive local ischemia. Support by microaxial pumps can make beating heart surgery safer and applicable for more complex cases.

Animals↗
PubMed2000

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.

Cardiac Surgical Procedures↗
PubMed1998

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.

Angina Pectoris↗
PubMed1998

First cardiological or cardiosurgical reintervention for ischemic heart disease after primary coronary artery bypass grafting.

OBJECTIVE: To study the first reintervention for ischemic heart disease anytime after coronary artery bypass grafting (CABG) and the variables that drive its need or bias its occurrence. Reintervention is defined as an isolated or combined repeat surgical or cardiological procedure for ischemic heart disease. METHODS: A consecutive series of 9600 CABG patients (1971-1992) were followed for up to 20 years (99.9% complete). A multivariable time-related analysis was performed. RESULTS: The 1-, 10- and 15-year freedom from reintervention was 99, 89 and 72% respectively. A three-phase hazard function was identified. Patient variables influencing early freedom included anginal instability, completeness of revascularization and institutional variables. Late freedom was influenced importantly by demographic variables, cardiac and non-cardiac comorbidity and extensive arterial grafting. The 1-month and 10-year survival after reintervention was 95 and 73%. The 1- and 10-year freedom from angina after reintervention was 74 and 32%. CONCLUSION: Reinterventions for ischemic heart disease by interventional cardiology or surgery are rather infrequent in the first decade after CABG but nearly half the patients surviving their second decade undergo one. The increased reintervention rate, apparent after 1985 did not go parallel with improved late post-CABG survival. Older age and the presence of multiple arterial grafts seem to reduce but also to bias the event. The very good survival, only when return of angina is present, suggests a more restrictive differential therapy approach, certainly in the presence of a well functioning arterial graft to the antero-septal region and where the co-morbidity might induce a high reinterventional survival cost.

Angioplasty, Balloon, Coronary↗
PubMed1998

The optimal mode of coronary revascularization for diabetics. A risk-adjusted long-term study comparing coronary angioplasty and coronary bypass surgery.

AIMS: Some recent studies have reported-superior outcomes for diabetic patients following coronary bypass surgery compared with coronary angioplasty. However, the available data are conflicting, are based on relatively small numbers of diabetic patients, and have limited duration of follow-up. The aims of this study were to compare risk adjusted long-term survival in diabetic patients following first-time revascularization via either coronary bypass surgery or coronary angioplasty; and, to identify variables independently associated with mortality. METHODS AND RESULTS: This was a two centre database project involving 15809 patients undergoing either coronary angioplasty or coronary bypass surgery as their initial revascularization procedure. Diabetes was present in 1938 (12%). Mean follow-up was 4.6+/-2.7 years for angioplasty and 6.6+/-4.3 years surgery diabetic patients. Multivariable time-related analyses in the hazard function domain for death were performed. Overall ten-year survival for pharmacologically treated diabetics was better after coronary bypass surgery (60%) than angioplasty (46%, <0.0001). However, the risk-adjusted survival advantage conferred by bypass surgery over angioplasty was strongest for patients receiving oral agents for diabetic control (75% vs 62%) and less impressive for diet (84% vs 81%) and insulin-treated diabetics (63% vs 64%). The major factors independently associated with worse outcome after angioplasty were incomplete revascularization, and the use of a sulfonylurea agent. The use of the left internal mammary graft improved survival in surgical patients. CONCLUSIONS: In general, diabetic patients had better long-term survival after bypass surgery than angioplasty. Incomplete revascularization and sulfonylurea therapy worsened outcome after angioplasty, and use of the left internal mammary improved outcome after bypass surgery.

Angioplasty, Balloon, Coronary↗
PubMed1997

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.

Ammonia↗
PubMed1997

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.

Adult↗
PubMed1997

Gastroepiploic artery coronary bypass graft: non-invasive patency evaluation using color and duplex Doppler ultrasonography.

OBJECTIVE: Color and duplex Doppler ultrasound and digital subtraction angiography were compared for the evaluation of graft patency of the gastroepiploic artery (GEA). METHODS: In 77 observations, ultrasound and digital subtraction angiography were compared. The coronary resistance index (cRI) was defined as the maximal systolic flow velocity minus the maximal diastolic flow velocity, divided by the maximal systolic flow velocity. On digital subtraction angiography, the graft was considered patent, occluded, or patent but non-functional. Grafts were defined as non-functional when they had a diameter of less than 5F with the absence of opacification of the native coronary artery. RESULTS: Of the 77 observations, 64 GEAs were patent angiographically, three were occluded and ten grafts were considered as patent but non-functional. Using color and duplex ultrasound, the GEA was identified in 65 out of 77 observations. There were no cases of false positive visualization of the GEA. All sonographically detected non-functional grafts (n = 7) had a cRI of greater than 0.60. When the non-visualized grafts are considered either non-functional or occluded, a cut-off value for a cRI of 0.60 results in a sensitivity and specificity of 100 and 75%, respectively. CONCLUSION: We propose ultrasound as a primary screening tool for evaluating graft patency. While color Doppler is a suitable technique for graft visualization, spectral analysis with the calculation of a cRI is required for functional evaluation.

Adult↗
PubMed1997

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.

Adult↗
PubMed1997

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.

Angina, Unstable↗
PubMed1997

Comparative study of three vaginal markers of the premature rupture of membranes. Insulin like growth factor binding protein 1 diamine-oxidase pH.

OBJECTIVE: To assess the diagnostic value of three vaginal markers-insulin-like growth factor binding protein 1 (= IGFBP1), diamine-oxidase (= DAO) and pH-for diagnosis of the premature rupture of membranes. STUDY: One hundred pregnant women participated in the study. They were divided into three groups: group A (34 cases with intact membranes), group B (35 cases with total rupture of the membranes), group C (31 cases of suspected rupture of the membranes). Each patient underwent three successive tests for each of the three markers. The test order was allocated at random. For pH the reaction is colorimetric, for DAO the reaction is radio-enzymatic and for IGFBP1 the reaction is immuno-chromatographic. All three reactions are qualitative in nature. The parameters studied were conventional statistical parameters (sensitivity = SN, specificity = SP, positive predictive value = PPV and negative predictive value = NPV). RESULTS: The analysis of the statistics gave the following results in percentages for SN, SP, PPV and NPV respectively; pH: 90.7%, 77.2%, 75%, 91.7%. DAO: 83.7%, 100%, 100%, 89%. IGFBP1: 95.3%, 98.2%, 97.6%, 96.5%. CONCLUSION: The determination of variations in pH is not satisfactory. IGFBP1 is at least better than DAO with, additionally, advantages of rapidity and simplicity.

Amine Oxidase (Copper-Containing)↗