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Jürgen Ennker

Publications and source records attributed to Jürgen Ennker.

14 recordsLinked to original sources
PubMed2006

Current determinants of 30-day and 3-month mortality in over 2000 aortic valve replacements: Impact of routine laboratory parameters.

OBJECTIVE: Haematological and biochemical measurements are performed routinely before surgery to exclude organ malfunction and blood cell and coagulation abnormalities. We aimed to test routinely obtained laboratory data as factors predicting operative risk. METHODS: Between 1996 and 2003, 2198 patients underwent aortic valve replacement (AVR) (908 of them with concomitant CABG) in our institute. The mean age of the study population was 69+/-11 years (range 13-91, 43% female). Clinical and laboratory parameters based on the consolidated data mart set were evaluated by multiple logistic regression analysis. RESULTS: The overall operative mortality (within 30 days) was 3.8% and the mortality after 3 months was 5.9%. In addition to clinical characteristics, the following laboratory values were identified as independent predictors of 30-day mortality: fasting blood glucose, antithrombine III, partial thromboplastine time and creatinine kinase. As independent predictors of 3-month mortality, the following laboratory values were indentified: fasting blood glucose, serum creatinine, antithrombine III, partial thromboplastine time, lactate dehydrogenase, sodium concentration and serum proteins. The discriminative power of the models increased if laboratory parameters were included in addition to preoperative clinical characteristics (from 0.75 to 0.79 and from 0.75 to 0.78 for 30-day and 3-month mortality, respectively). The discriminative power using the logistic EuroScore was lower (0.71 and 0.7, for 30-day and 3-month mortality, respectively). CONCLUSIONS: Laboratory parameters as objective markers for organ function and nutritional status are useful data for the prediction of 30-day and 3-month mortality after aortic valve replacement. Using modern methods of information technology, these valuable data which are stored electronically in most hospitals, can be used efficiently for research and quality control.

Adolescent↗
PubMed2005

Prevalence and risks of undiagnosed diabetes mellitus in patients undergoing coronary artery bypass grafting.

BACKGROUND: Numerous studies have shown that diabetes mellitus (DM) is not identified and, consequently, inadequately treated in a substantial proportion of the patients in the general population. We know very little about the extent and the consequences of undiagnosed diabetes in the risk group of patients with coronary heart diseases. The objective of this study was therefore to determine the prevalence and the risks of undiagnosed DM among patients with coronary artery bypass. METHODS AND RESULTS: The data of 7310 patients who have undergone coronary bypass operations between 1996 and 2003 were analyzed. Depending on their diagnosis on admission and their fasting plasma glucose (FPG) level, these patients were classified as known diabetics, undiagnosed diabetics (FPG > or =126 mg/dL), or as nondiabetics (FPG <126 mg/dL) and were compared in terms of their preoperative, intraoperative, and postoperative characteristics. Among the patients with coronary bypass that we examined, we found a prevalence of diagnosed diabetics of 29.6%. The prevalence of patients with undiagnosed DM (FPG > or =126 mg/dL) was 5.2%. In comparison with the other groups (non-DM versus undiagnosed DM versus known DM), the undiagnosed diabetics more frequently required resuscitation (1.7% versus 4.2% versus 1.5%; P<0.01) and reintubation (2.1% versus 5.0% versus 3.5%; P<0.01) and often showed a longer period of ventilation >1 day (5.6% versus 10.5% versus 7.4%; P<0.01). Perioperative mortality rate was highest in this group (0.9% versus 2.4% versus 1.4%; P<0.01). CONCLUSIONS: This study is the first to publish the prevalence of undiagnosed diabetes mellitus in cardiac surgery. During the perioperative and postoperative courses, these patients displayed a substantially higher morbidity and mortality rate.

Aged↗
PubMed2005

Stentless bioprostheses in small aortic roots: impact of patient-prosthesis mismatch on survival and quality of life.

BACKGROUND AND AIM OF THE STUDY: Although stentless bioprostheses offer hemodynamic advantages, prosthetic valves of smaller size may provide less reduction of left ventricular hypertrophy and, therefore, affect survival and quality of life. METHODS: A total of 303 patients (mean age 75 +/- 7 years) who underwent aortic valve replacement with the stentless Freestyle bioprostheses were followed up. The impact of projected indexed effective orifice area (IEOA) on survival and quality of life (QoL) was determined multivariately by Cox regression and logistic regression analysis. RESULTS: Independent predictors of survival time were diabetes mellitus (p < 0.001), atrial fibrillation (p = 0.004), male gender (p = 0.015), peripheral vascular disease (p = 0.039), and patient-prosthesis mismatch (PPM, defined as projected IEOA < 0.75 cm2/m2) in patients with aortic regurgitation (p = 0.017). A history of congestive heart failure (p = 0.016), small body mass index (p = 0.01), age > 75 years (p = 0.002) and small projected IEOA (p = 0.016) were identified as predictors of impaired QoL. CONCLUSION: PPM and small projected IEOA were identified as independent risk factors for impaired mid-term survival and QoL. As the occurrence of PPM was rare in total root replacements, and the implantation procedure did not increase the operative risk in the present patient population, the recommendation is made to consider this implantation technique if a small projected IEOA is expected.

Activities of Daily Living↗
PubMed2004

Hyperkalemic blood versus crystalloid cardioplegia in longer clamping times.

The 715 patients who had crystalloid cardioplegia were compared with 5419 who had cold hyperkalemic blood cardioplegia for isolated coronary artery grafting from 1996 through 2001. Creatine kinase-MB was measured preoperatively, at 90 min, and 7 hours after the end of extracorporeal circulation. Correlation of post-bypass creatine kinase-MB release with aortic crossclamp time and other variables in the two cardioplegia groups was made using dichotomous encoding of cardioplegia in a multivariate linear regression model. Creatine kinase-MB levels 90 min after bypass were higher in patients who had crystalloid cardioplegia than in those who had blood cardioplegia. There was a linear relationship between aortic crossclamp time and post-bypass creatine kinase-MB release in both cardioplegia groups. Post-bypass creatine kinase-MB release increased with aortic crossclamp time independently of other factors and significantly more with crystalloid cardioplegia than with blood cardioplegia (the slope of the regression line was 0.230 versus 0.106). Intraaortic balloon pumping was used less frequently in the blood cardioplegia group. There was an advantage with blood cardioplegia for myocardial protection in longer aortic crossclamp times for isolated coronary bypass grafting.

Biomarkers↗
PubMed2004

Impact of age on the results of coronary artery bypass grafting.

As the average age of patients undergoing cardiac surgery is increasing, the effects of age on the incidence of postoperative complications and 30-day mortality after coronary artery bypass grafting were examined. The EuroSCORE and corresponding age-stripped EuroSCORE were calculated in 6,057 patients who underwent isolated coronary bypass between January 1996 and January 2002. Both EuroSCORE and age-stripped EuroSCORE exhibited a significant increase with age in the whole group of patients and in those who were alive 30 days after surgery. The 30-day mortality and the incidence of postoperative complications increased significantly with age. A significant age-dependent increase in EuroSCORE was found in patients who died within 30 days postoperatively, whereas no age dependence was observed in the age-stripped EuroSCORE. Univariate analysis showed diabetes mellitus and atrial fibrillation to be significant risk factors for 30-day mortality; atrial fibrillation was also found to significantly affect 30-day mortality on multivariate analysis. In view of the increasing co-morbidity and age-dependent organ changes in the elderly, specific preventive and therapeutic measures are needed in this group of patients undergoing cardiac surgery.

Age Factors↗
PubMed2004

Data mart based research in heart surgery: challenges and benefit.

For many new medical research questions in heart surgery comprehensive and large data bases are essential. We discuss typical challenges for the integration of real-time and legacy data stored in multiple unconnected hospital information systems (HIS). Furthermore the HIS are often operated by autonomous departments whose data base structures are subject to occasional modifications. We present a solution which integrates and consolidates all research relevant data in a data mart without imposing any considerable operational or maintenance contract liability risk for the existing HIS. The problems of partial consistency and partial redundancy in the data are discussed. The data mart system serves multiple purposes: beside clinical reporting and quality assessment, the preparation steps for comprehensive studies are enormously simplified.

Biomedical Research↗
PubMed2003

Creatinine clearance versus serum creatinine as a risk factor in cardiac surgery.

BACKGROUND: Renal impairment is one of the predictors of mortality in cardiac surgery. Usually a binarized value of serum creatinine is used to assess the renal function in risk models. Creatinine clearance can be easily estimated by the Cockcroft and Gault equation from serum creatinine, gender, age and body weight. In this work we examine whether this estimation of the glomerular filtration rate can advantageously replace the serum creatinine in the EuroSCORE preoperative risk assessment. METHODS: In a group of 8138 patients out of a total of 11878 patients, who underwent cardiac surgery in our hospital between January 1996 and July 2002, the 18 standard EuroSCORE parameters could retrospectively be determined and logistic regression analysis performed. In all patients scored, creatinine clearance was calculated according to Cockcroft and Gault. The relationship between the predicted and observed 30-days mortality was evaluated in systematically selected intervals of creatinine clearance and significance values computed by employing Monte Carlo methods. Afterwards, risk scoring was performed using a continuous or a categorical value of creatinine clearance instead of serum creatinine. The predictive ability of several risk score models and the individual contribution of their predictor variables were studied using ROC curve analysis. RESULTS: The comparison between the expected and observed 30-days mortalities, which were determined in different intervals of creatinine clearance, revealed the best threshold value of 55 ml/min. A significantly higher 30-days mortality was observed below this threshold and vice versa (both with p < 0.001). The local adaptation of the EuroSCORE is better than the standard EuroSCORE and was further improved by replacing serum creatinine (SC) by creatinine clearance (CC). Differential ROC analysis revealed that CC is superior to SC in providing predictive power within the logistic regression. Variable rank comparison identified CC as the best single variable predictor, even better than the variable age, former number 1, and SC, previously number 9 in the standard set of EuroSCORE variables. CONCLUSION: The renal function is an important determinant of mortality in heart surgery. This risk factor is not well captured in the standard EuroSCORE risk evaluation system. Our study shows that creatinine clearance, calculated according to the Cockcroft and Gault equation, should be applied to estimate the preoperative renal function instead of serum creatinine. This predictor variable replacement gains a significant improvement in the predictive accuracy of the scoring model.

Adult↗
PubMed2003

[Impact of age on postoperative events and mortality in cardiac surgery].

BACKGROUND AND OBJECTIVE: The number of "older" patients undergoing cardiac surgery is steadily increasing. In the year 2000, 37% of all patients who underwent a cardiac operation in Germany were > or = 70 years. Looking at data from our institution, we analyzed the impact of age on postoperative events and mortality in cardiac surgery. PATIENTS AND METHODS: Data from 7,048 patients who underwent cardiac surgery in our institution from January 1996 until January 2002 were analyzed. For all patients, EuroSCORE and the corresponding age-stripped value were calculated. All recorded postoperative complications and 30-day mortality were statistically analyzed. RESULTS: EuroSCORE as well as the age-stripped EuroSCORE showed a significant rise with increasing age in the total number of patients as well as in the patients, who did not die during the first 30 days after the operation. 30-day mortality and the incidence of postoperative complications increased significantly with age. While the EuroSCORE showed a significant age-dependent increase in patients who died within 30 days after the operation, the age-stripped EuroSCORE did not reveal a significant discrepancy in mortality with respect to age. CONCLUSION: Our data confirm that the age alone of a patient undergoing cardiac surgery has to be regarded as one of the important independent risk factors for mortality. In order to limit mortality in the steadily growing number of older and multimorbid patients undergoing cardiac surgery, exceptional emphasis has to be put on patient selection and therapeutic measures to improve preoperative status.

Age Factors↗
PubMed2003

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

BACKGROUND: Stroke after cardiac surgery is a devastating complication. The relationship between white blood cell count (WBC) and perioperative cerebrovascular accident (CVA) has not been investigated. An effort was made to identify how preoperative WBC may relate to CVA development during or after cardiac surgery. METHODS: Prospective data were collected from 7,483 patients who underwent coronary artery bypass grafting or valvular surgery or both. WBC was determined preoperatively and postoperatively. Differentiation of WBC was examined only preoperatively. RESULTS: There were a total of 125 CVAs (10 transient ischemic attacks [TIAs], 115 strokes). WBC was significantly higher preoperatively and directly postoperatively in patients with stroke. Qualitative changes in preoperative WBC were also found in these patients (chi2; p < 0.001). The predictive power of the stepwise logistic regression model for CVA was greater when preoperative WBC was included. The risk for perioperative CVA increased starting at preoperative WBC of 9 x 10(9)/L (p = 0.044) and progressed in higher WBC ranges. WBC had a significant impact on CVA outcome (analysis of variance, p = 0.001). CONCLUSIONS: Our studies have established the correlation between high preoperative WBC and stroke during or after cardiac surgery. Furthermore, elevated preoperative WBC was related to the clinical outcome of CVA. Preoperative measures aimed at preventing or treating conditions such as infections that may cause elevated WBC may be beneficial in the prevention of stroke during or after cardiac surgery.

Aged↗
PubMed2003

Risk in elderly patients after stentless versus stented aortic valve surgery.

Recent studies suggest that the hemodynamic advantage of stentless bioprostheses over the stented type improves long-term survival after aortic valve replacement, but the more complex and time-consuming implantation technique may increase the risks of operative death and postoperative complications. Between April 1996 and June 2001, 519 patients with a mean age of 76 +/- 5 years underwent aortic valve replacement using a stentless (Medtronic Freestyle, n = 277) or stented bioprosthesis (Medtronic Mosaic, n = 242). Multiple logistic regression analysis considering different patient populations revealed no increased risk of operative death, postoperative complications, or neurological impairment after implantation of a stentless bioprosthesis. Survival curves in respect of 367 patients who underwent aortic valve replacement up to September 2000 and were followed up for 3 years were not different (p = 0.98). As the patients were elderly, improved survival due to implantation of a stentless valve could not be demonstrated within this time span.

Aged↗
PubMed2003

[Regional lung edema in acute mitral valve insufficiency following chordae tendineae rupture with prolapse of the posterior mitral valve leaflet].

An unilateral or predominantly lobar pulmonary edema is an unusual clinical or radiological finding, often misdiagnosed as one of the more common causes of focal lung disease. We report 2 cases of a regional pulmonary edema caused by the acute onset of a severe mitral insufficiency after the rupture of chordae tendinae resulting in a prolaps of the posterior mitral leaflet. In both cases the regional pulmonary edema was initially misdiagnosed as a pneumonic infiltration, which delayed the cardiological diagnostical procedures and the surgical intervention. The mechanism of the regional edema is an excentric recurgitation jet into the left atrium, which is usually directed to the orifice of the right upper lobe pulmonary vein which increases the hydrostatic vascular pressure in the corresponding lung segment. For the confirmation of the diagnosis, transesophageal echogradiographic is helpful in documenting the direction of the regurgitant flow and detecting differential gradients between the right and left pulmonary venous systems. The pulmonary infiltrations, which persisted for several weeks, disappeared within a few days after surgical mitral-valve-reconstruction in both cases.

Aged↗
PubMed2002

Is age an independent determinant of mortality in cardiac surgery as suggested by the EuroSCORE?

BACKGROUND: The proportion of older patients in cardiac surgery is continuously increasing. 37% of patients undergoing heart surgery in Germany in the year 2000 were 70 years of age and older. We have studied the role of age as a determinant of mortality in cardiac surgery in our institutional patient population. METHODS: We have calculated the EuroSCORE and the corresponding age-adjusted EuroSCORE in 8769 patients who underwent heart surgery between January 1996 and January 2002 and collected the information on the occurrence of postoperative complications and 30-days mortality. RESULTS: The multimorbidity increased with ascending age. Both the EuroSCORE and the age-adjusted EuroSCORE values increased significantly with age in the whole group of patients as well as in the group of patients who were alive 30 days after heart surgery. The incidence of postoperative complications and 30-days mortality increased significantly with age. In patients who died within 30 days after surgery, the EuroSCORE increased significantly with age, whereas the age-adjusted EuroSCORE did not. The occurrence of diabetes mellitus, arterial hypertension and atrial fibrillation, i.e., the risk factors not considered by the EuroSCORE, exhibited a significant age dependence in our patients. The univariate analysis identified the significant dependence of 30-days mortality on diabetes and atrial fibrillation. The stepwise logistic regression analysis showed the dependence of mortality on diabetes. CONCLUSIONS: On the background of the well-known age-dependent structural and functional changes of different body organs, our data show that age is a significant risk indicator in cardiac surgery, strongly correlating with morbidity and mortality. Consequently, special preventive and therapeutic measures are required in clinical environment in the case of elderly patients undergoing cardiac surgery.

Age Factors↗
PubMedDate not supplied

The stentless freestyle bioprosthesis: impact of age over 80 years on quality of life, perioperative, and mid-term outcome.

BACKGROUND: The steadily increasing life expectancy of the population in the Western World, together with the progress in noninvasive diagnostic methods and operating techniques lead to an increase in aortic valve surgery in elderly people. AIM OF THE STUDY: Is there an increased risk of adverse perioperative and mid-term outcome for octogenarians and do they benefit from aortic valve replacement (AVR) with stentless bioprostheses? METHODS: Between 1996 and 2002, 503 patients older than 60 years underwent AVR with a stentless Freestyle bioprosthesis. Seventy-six of them were older than 80 years. The risk of operative mortality, perioperative complications, valve-related morbidity for octogenarians was determined by multivariate logistic regression. RESULTS: In general, risk-adjusted analyses did not reveal an increased risk of operative mortality (p = 0.4), postoperative atrial fibrillation (p = 0.2), prolonged ventilation (p = 0.5), prolonged stay in the intensive care unit (p = 0.3), or mid-term valve-related morbidity as prosthetic valve endocarditis (p = 0.2), reoperation (p = 0.4), bleeding events (p = 0.1), and stroke (p = 0.8) for octogenarians. Continuously increasing age was an independent risk factor for postoperative neurological complications (OR = 1.8 per 10 years, p = 0.04). Quality of life was equal to or better than the general population of the same age. Median survival time of octogenarians was 5.2 +/- 0.5 years. CONCLUSIONS: Except for postoperative neurological complications, octogenarians receiving stentless bioprostheses had no increased risk of adverse perioperative and mid-term outcome in comparison to younger patients. As quality of life and life expectancy after AVR with stentless valves were equal to the general population, AVR with stentless bioprostheses should not be withheld from octogenarians.

Age Factors↗