Clinical performance of the EuroSCORE II compared with the previous EuroSCORE iterations.

BACKGROUND: The European System for Cardiac Operative Risk Evaluation (EuroSCORE) II has been recently introduced as an update to the previous versions. We sought to evaluate the predictive performance of the EuroSCORE II model against the original additive and logistic EuroSCORE models. PATIENTS AND METHODS: The study included 1,247 consecutive patients who underwent cardiac surgery procedures during a 14-month period starting from the beginning of 2012. The original additive and logistic EuroSCORE models were compared with the EuroSCORE II focusing on the accuracy of predicting hospital mortality. RESULTS: The overall hospital mortality rate was 3.45%. The discriminative power of the EuroSCORE II was modest and similar to other algorithms (C-statistics 0.754 for additive EuroSCORE; 0.759 for logistic EuroSCORE; and 0.743 for EuroSCORE II). The EuroSCORE II significantly underestimated the all-patient hospital mortality (3.45% observed vs. 2.12% predicted), as well as in the valvular (3.74% observed vs. 2% predicted), and combined surgery cohorts (6.87% observed vs. 3.64% predicted). The predicted EuroSCORE mortality significantly differed from the observed mortality in the third and the fourth quartile of patients stratified according to the EuroSCORE II mortality risk (p < 0.05). The calibration of the EuroSCORE II was generally good for the entire patient population (Hosmer-Lemeshow [HL] p = 0.139), for the valvular surgery subset (HL p = 0.485), and for the combined surgery subset (HL p = 0.639). CONCLUSION: The EuroSCORE II might be considered a solid predictive tool for hospital mortality. Although, the EuroSCORE II employs more sophisticated calculation methods regarding the number and definition of risk factors included, it does not seem to significantly improve the performance of previous iterations.

Locally derived system for cardiac operative risk evaluation.

INTRODUCTION: During the last two decades, many authors have found that European Systems for Cardiac Operative Risk Evaluation (additive and logistic models) overestimate the risk in cardiac surgery. The new European model has recently been introduced as an update to previous versions. The aim of the study was to investigate the significance of locally derived system for cardiac operative risk evaluation and to compare its predictive power with the existing European systems. MATERIAL AND METHODS: For developing a local risk prediction model, data from 2681 patients submitted to cardiac surgery at the Institute of Cardiovascular Diseases Vojvodina have thoroughly been collected. Logistic regression analysis was used to construct a local model for prediction of outcome. The evaluation of the local model and three European systems was performed by comparing the observed and expected hospital mortality. RESULTS: The difference between the predicted and observed mortality regardless of the type of surgery was statistically insignificant for the additive European system (p=0.073) and the local model (p=0.134). The logistic European system overestimated the operative risk, while the new European model underestimated mortality. In coronary surgery, all models, except the logistic European system, performed well. In valvular surgery, the new European model and the local model underestimated mortality significantly, while the additive and logistic European models performed well. In combined surgery, the new European system significantly underestimated mortality (p=0.029), while the local model performed well (p=0.252). CONCLUSION: The locally derived model shows satisfactory results, with good calibration and discriminative power. The local model specifically outperforms all other European systems in terms of discriminatory power in combined surgery subset.

Vojvodinascore--local system for cardiac operative risk evaluation.

INTRODUCTION: The aim of the study was to investigate the prognostic value, sensitivity and specificity of both the logistic and additive European System for Cardiac Operative Risk Evaluation (as well as the European System for Cardiac Operative Risk Evaluation II and to assess the necessity for developing a local outcome prediction model in cardiac surgery. MATERIAL AND METHODS: The research included 406 consecutive patients who had undergone cardiac surgical procedures at Institute of Cardiovascular Diseases of Vojvodina from January 2012 to July 2012. The authors compared the predicted mortality according to the additive and logistic European Systems for Cardiac Operative Risk Evaluation, the new European System for Cardiac Operative Risk Evaluation II and the observed mortality (30 days after surgery). RESULTS: The difference between the predicted and observed mortality regarding the whole group of 406 operated cardiac patients was not statistically significant for the additive European System for Cardiac Operative Risk Evaluation (p = 0.081) and the European System for Cardiac Operative Risk Evaluation II (p = 0.164), but it was statistically significant for the logistic European System for Cardiac Operative Risk Evaluation (p = 0.031). The areas under the receiver operating characteristic curves are statistically different from 0.5 for both models (additive and logistic European System for Cardiac Operative Risk Evaluation), as well as for the European System for Cardiac Operative Risk Evaluation II. However, the proper classification of the patients has not been observed since their sensitivity and specificity are not satisfactory. CONCLUSION: The additive and logistic European Systems for Cardiac Operative Risk Evaluation overestimate while the European System for Cardiac Operative Risk Evaluation II underestimates the risk in cardiac surgery. We believe that a locally derived model would be of great use in the everyday clinical practice since it would faithfully illustrate the actual state of patient population of the region where it was developed. At the same time it would provide the accurate prediction of surgical outcome.

[Postoperative nonlethal complications following open heart surgery].

BACKGROUND/AIM: Postoperative nonlethal complications after open heart surgery are a serious clinical problem causing a considerable engagement of health workers, an augmented use of drugs, and prolonged operation incapac ity leading to prolonged hospital stay and increased expenses. The aim of the study was to establish whether there is any correlation between the level of expected operative risk and postoperative nonlethal complications. METHODS: A consecutive series of 853 patients subjected to the open heart surgery were investigated, 622 (73%) males and 231 (27%) females. The average age of the patients was 57.2 +/- 9.9 (16-81) years. The patients were divided into 3 groups according to the additive EuroSCORE model: groups I, II and III with the expected operative risk of 0%-2%, 2%-5% and over 5%, respectively. The data were collected prospectively and analyzed retrospectively. Statistical methods of correlation and t-test were used. RESULTS: A high degree of correlation between the operative risk level and frequency of postoperative nonlethal complications (R = 0.98) was found. The average rate of complications was 24% for the whole group of 853 patients. It accounted for 21%, 29% and 47% in the groups I, II and III, respectively. According to the expected operative risk level there was a statistically significant difference in respect of heart arrhythmias (p = 0.02), neurologic complications (p = 0.002), and pulmonary complications (p = 0.009). CONCLUSION: Our results show a high degree of correlation between the expected level of operative risk according to the EuroSCORE model and the frequency of postoperative nonlethal complications. There is a statistically significant difference in respect to frequency of heart rhythm disturbances, pulmonary and neurological complications and expected operative mortality.

Patency of internal thoracic artery and vein grafts according to revascularized coronary artery properties.

Long-term results of surgical myocardial revascularization are determined by the quality of grafts and the progression of atherosclerosis in coronary arteries. The aim of the study was to evaluate the patency rate of internal thoracic artery and great saphenous vein grafts in relation to the hemodynamic properties of revascularized coronary artery. The patency of internal thoracic artery and great saphenous vein grafts was analyzed in relation to the degree of coronary stenosis estimated by angiography and the diameter of distal portion of coronary artery assessed intra-operatively. The long-term patency of great saphenous grafts depends on the distal coronary artery diameter but not on the degree of coronary artery stenosis. The patency of internal thoracic artery graft depends on the degree of coronary artery stenosis but not on the distal coronary artery diameter. The internal thoracic artery is the superior graft in coronary surgery, but the low patency rate in case of moderate coronary artery stenosis emphasizes the importance of selective approach.

[Ministernotomy: a preliminary experience in heart valve surgery].

BACKGROUND/AIM: The last decade of the 20th century brought up a significant development in the field of minimally invasive approaches to the valvular heart surgery. Potential benefits of this method are: good esthetic appearance, reduced pain, reduction of postoperative hemorrhage and incidence of surgical site infection, shorter postoperative intensive care units (ICU) period and overall in-hospital period. Partial upper median stemotomy currently presents as a state-of-the art method for minimally invasive surgery of cardiac valves. The aim of this study was to report on initial experience in application of this surgical method in the surgery of mitral and aortic valves. METHODS: The study was designed and conducted in a prospective manner and included all the patients who underwent minimally invasive cardiac valve surgery through the partial upper median stemotomy during the period November 2008 - August 2009. We analyzed the data on mean age of patients, mean extubation time, mean postoperative drainage, mean duration of hospital stay, as well as on occurance of postoperative complications (postoperative bleeding, surgical site infection and cerebrovascular insult). RESULTS: During the observed period, in the Institute for Cardiovascular Diseases of Vojvodina, Clinic for Cardiovascular Surgery, 17 ministernotomies were performed, with 14 aortic valve replacements (82.35%) and 3 mitral valve replacements (17.65%). Mean age of the patients was 60.78 +/- 12.99 years (64.71% males, 35.29% females). Mean extubation time was 12.53 +/- 8.87 hours with 23.5% of the patients extubated in less than 8 hours. Mean duration of hospital stay was 12.35 +/- 10.17 days (in 29.4% of the patients less than 8 days). Mean postoperative drainage was 547.06 +/- 335.2 mL. Postoperative complications included: bleeding (5.88%) and cerebrovascular insult (5.88%). One patient (5.88%) required conversion to full stemotomy. CONCLUSION: Partial upper median sternotomy represents the optimal surgical method for the interventions on the whole ascendant aorta (including aortic valve) and mitral valve through the roof of the left atrium, with a few significant advantages compared to the full stemotomy surgical approach.

Myocardial revascularization without extracorporeal circulation in patients at high operative risk.

It is considered that over 25% of surgical patients with coronary artery disease are treated without extracorporeal circulation, i.e. off-pump coronary artery bypass. The aim of the study was to evaluate results of surgical myocardium revascularization in patients at high operative risk. During the period 2005-2008, 148 patients were operated without the use of extracorporeal ciruculation. According to the logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) stratification, 28 patients (19%) were designated as the high risk patients. The average age of these high risk patients was 72 years (55-86). The group consisted of 23 men (82.1%) and 5 women (17.8%). The postoperative mortality in the whole group of patients was 0.68% (1/148), whereas it was 0% in the high risk group. The average number of coronary anastomoses was 2.4. Eight patients (28.6%) had some sort of postoperative complications. Our results demonstrate safety and efficacy of surgical revascularization without cardiopulmonary bypass in patients at high operative risk.

[Prevention of sudden cardiac death by the implantable cardioverter defibrilator].

INTRODUCTION; Sudden cardiac death or, as it is also called, a modern man's killer occurs a few hours after the beginning of the disease. Sudden death is the one that happens within an hour from the onset of the subjective discomforts regardless of the existence of any previous disease. According to modern statistics, 450.000 people die suddenly in the USA and 150,000 in Germany. CAUSES OF SUDDEN DEATH: The most frequent causes of sudden death are cardiologic or, in other words, a heart rhythm disorder such as ventricular tachycardia, ventricular fibrillation and bradycardiac rhythm disorder. All these reasons can be efficiently prevented by the implantation of the cardioverter defibrillators. IMPLANTABLE CARDIOVERTER DEFIBRILLATOR: In comparison with the already known medications, the defibrillator seems to be the most efficient in prevention of sudden cardiac death. This fact has been confirmed by large multicentre studies. The implantation itself is a routine procedure. It lasts about an hour and it often passes without any complications. The patient leaves the hospital a few days after the procedure. About 150 of these procedures are performed per year at the Institute of Cardiovascular Diseases Vojvodina. The Social Insurance Fund bears medical costs and the patient only pays the participation fee, which is symbolical if compared to the value and use of the device. Owing to this fact, this device is available to every patient thus making the efficient sudden cardiac death prevention possible.

Correlation between EuroSCORE and intensive care unit length of stay after coronary surgery.

During the last several years many authors have found that the European System for Cardiac Operative Risk Evaluation is useful in the prediction of not only postoperative mortality but also of the length of stay in the intensive care unit, complication rate and overall treatment expenses. This study included 329 patients who had undergone isolated surgical myocardial revascularization at our Department during the period from January 1st to June 6th, 2008. For the operative risk evaluation, the additive European System for Cardiac Operative Risk Evaluaion was used. In group I (low risk 0-2%) there were 144 patients (43.7%), whereas group II (medium risk 3-5%) and group III (high risk > or = 6%) included 141 (42.8%) and 44 (13.4%) patients, respectively. The length of stay in the intensive care unit was 25.56, 32.43 and 49.59 hours for groups I, II and III, respectively. The difference in the mean length of stay in the intensive care unit between the groups was highly statistically significant (p < 0.001) with a positive correlation (R = 0.193; p < 0.001). There is a positive correlation in patients who had undergone surgical myocardial revascularization in terms of operative risk expressed by the additive European System for Cardiac Operative Risk Evaluation and length of stay in the intensive care unit, total intubation period and development of early postoperative complications.

[Evaluation of results in coronary surgery using EuroSCORE].

INTRODUCTION: The European System for Cardiac Operative Risk Evaluation (EuroSCORE) was developed in order to predict operative risk in cardiac surgery and to assess the quality of the cardio-surgical care. Introduction of the uniform terminology in result evaluation process leads to the significant improvement in measuring and evaluation of surgical treatment quality. OBJECTIVE: The aim of the study was to evaluate our results in isolated coronary surgery using the EuroSCORE. METHODS: The study was done respectively by analysing predicted mortality according to the EuroSCORE model and observed operative risk in 4,675 coronary patients operated at our Clinic during the period 2001-2008. For statistical analyses, the Pearson, Chi-square and ANOVA tests were used. RESULTS: The total postoperative mortality predicted by the EuroSCORE was 2.9 +/- 2.25, while the observed one was 2.2%. When the scoring system and observed results were compared over the years, a considerably lower observed mortality was found during the last 4 years. Overall average number of distal anastomoses was 2.62 +/- 0.84. During the period 2004-2008, the average number of coronary anastomoses increased over the years reaching the value of 2.77 +/- 0.88. The difference is at the level of statistical significance with the trend of further increase. Percentage of the patients with single or double graft myocardial revascularization decreases, while the number of the patients with triple or more bypasses increases. CONCLUSION: During the last years, the results in isolated coronary surgery have considerably improved. The EuroSCORE overestimates operative risk. In order to improve its predictive value, the model should be recalibrated.

[Trends of risk factors in coronary surgery].

INTRODUCTION: In current era of widespread use of percutaneous coronary interventions (PCI), it is debatable whether coronary artery by-pass graft (CABG) patients are at higher risk. OBJECTIVE: The aim of the study was to evaluate trends in risk profile of isolated CABG patients. METHODS: By analysing the EuroSCORE and its risk factors, we reviewed a consecutive group of 4675 isolated CABG patients, operated on during the last 8 years (2001-2008) at our Clinic. The number of PCI patients was compared to the number of CABG patients. For statistical analyses, Pearson's chi-square and ANOVA tests were used. RESULTS: The number of PCI increased from 159 to 1595 (p < 0.001), and the number of CABG from 557 to 656 (p < 0.001). The mean EuroSCORE increased from 2.74 to 2.92 (p = 0.06). The frequency of the following risk factors did not change over years: female gender, previous cardiac surgery, serum creatinine > 200 micromol/l, left ventricular dysfunction and postinfarct ventricular septal rupture. Chronic pulmonary disease, neurological dysfunction, and unstable pectoral angina declined significantly (p < 0.001). Critical preoperative care declined from 3.1% in 2001 to 0.5% in 2005, than increased and during the last 3 years did not change (2.3%). The mean age increased from 56.8 to 60.7 (p < 0.001) and extracardiac arteriopathy increased from 9.2% to 22.9% (p < 0.001). Recent preoperative myocardial infarction increased from 11% to 15.1% (p = 0.021), while emergency operations increased from 0.9% to 4.0% (p = 0.001). CONCLUSION: The number of CABG increases despite the enlargement of PCI. The risk for isolated CABG given by EuroSCORE increases over years. The risk factors, significantly contributing to higher EuroSCORE are: older age, extracardiac arteriopathy, recent myocardial infarction and emergency operation.

[Hospital infections at the Department of Cardiovascular Surgery].

INTRODUCTION: Despite modern surgical techniques, preoperative preventive use of antibiotics and optimal treatment of operative site, patients who underwent surgical procedures are still at a risk of developing hospital infections. The aim of this paper was to estimate the frequency of hospital infections at the Department of Cardiovascular Surgery and their presence according to the anatomic localization as well as to identify the most frequent causes of hospital infections. MATERIAL AND METHODS: During one-year period, all surgically treated patients were prospectively followed at the Department of Cardiovascular Surgery of the Institute of Cardiovascular Diseases, Vojvodina. There were 1302 patients who underwent 1396 surgical procedures during the period observed The descriptive epidemiological method was applied in the study. The following odds ratio and rates were calculated: the incidence rate of patients with hospital infections, the incidence rate of hospital infections and the incidence rate in relation to hospital stay of each patient (incidence density). RESULTS: During that period, 36 hospital infections were recorded in 33 patients. The average incidence rate of patients with hospital infection was 2.53% and hospital infection rate was 2.58% (from 0% to 5.13%). The male-female ratio was 3.1:1. The most frequent hospital infections were surgical site infections (incidence rate 0.86%), then gastroenteritis (incidence rate 0.77%) and bloodstream infections (incidence rate 0.46%). The most common causes of hospital infections were: Staphylococcus aureus (14.8%), Acinetobacter spp (22.2%) and coagulase negative staphylococcus (11.1%). CONCLUSION: The fact is that the incidence rate of hospital infections is relatively low, and such a trend can continue only if the continuous epidemiological control and preventive measures are implemented in the future.

Surgical treatment of heart failure in patients with primary and ischemic dilated cardiomyopathy.

OBJECTIVE: The aim of this study was to show hemodynamic and clinical improvement of heart failure after reductive annuloplasty of double (mitral and tricuspid) orifices (RADO) in the treatment of ischemic (IDCM) and primary (PDCM) dilated cardiomyopathy. MATERIALS AND METHODS: From November 1986 to July 15, 2002, 341 patients underwent operations for dilated cardiomyopathy. The IDCM group consisted of 231 patients (68%) with a mean ejection fraction (EF) of 23.3%. From July 1991 to July 15, 2002, the 110 patients in the PDCM group (mean EF, 22.9%) underwent such operations. RESULTS: The postoperative 30-day mortality rate was 5.9% for the entire patient population, 7.3% for the IDCM group, and 2.7% for the PDCM group. Follow-up survival rates were 61.5% +/- 4.0% at 5 years and 38.2% +/- 8.0% at 14 years for the IDCM group and 43.9% +/- 5.6% at 5 years and 21.3% +/- 8.5% at 10 years for the PDCM group. CONCLUSION: RADO corrects remodeling of the fibrous skeleton of the heart, changes the spherical geometry of the left ventricle, improves the hemodynamic action of the left and right ventricles, and slows down the progression of heart failure. We recommend the RADO procedure as an important associated procedure in the surgical treatment of IDCM and as a new surgical alternative for treating the early stage of PDCM immediately after the first decompensation.

Reductive annuloplasty of double orifices in patients with primary dilated cardiomyopathy.

BACKGROUND: Patients with primary dilated cardiomyopathy exhibit extensive remodeling of the left ventricle, mitral and tricuspid annular dilation and both mitral and tricuspid regurgitation. These factors significantly contribute to heart failure, and are predictors of early lethal outcome. The aim of this study is to show hemodynamic and clinical improvement after reductive annuloplasty of both mitral and tricuspid orifices in primary dilated cardiomyopathy. METHODS: There were 76 patients with primary dilated cardiomyopathy. Mitral annuloplasty using a Carpentier-Edwards sizer was performed on 9 patients, and posterior semicircular reductive annuloplasty was performed on 67 patients. Modified De Vega's tricuspid annuloplasty was performed on all patients. RESULTS: Immediate and long-term results showed significant improvement in hemodynamic values and myocardial contractility after operation. CONCLUSIONS: Reductive annuloplasty of both mitral and tricuspid orifices corrects remodeling of the left ventricle of the heart, changes sphericity and geometry of the left ventricle, improves hemodynamic action of the left and right ventricle, and slows down progression of heart failure. We recommend reductive annuloplasty of both mitral and tricuspid orifices before or soon after the first decompensation.