A review and assessment of cyanobacterial toxins as cardiovascular health hazards.

Eutrophicated waters frequently support bloom-forming cyanobacteria, many of which produce potent cyanobacterial toxins (cyanotoxins). Cyanotoxins can cause adverse health effects in a wide range of organisms where the toxins may target the liver, other internal organs, mucous surfaces and the skin and nervous system. This review surveyed more than 100 studies concerning the cardiovascular toxicity of cyanotoxins and related topics. Over 60 studies have described various negative effects on the cardiovascular system by seven major types of cyanotoxins, i.e. the microcystin (MC), nodularin (NOD), cylindrospermopsin (CYN), anatoxin (ATX), guanitoxin (GNTX), saxitoxin (STX) and lyngbyatoxin (LTX) groups. Much of the research was done on rodents and fish using high, acutely toxin concentrations and unnatural exposure routes (such as intraperitoneal injection), and it is thus concluded that the emphasis in future studies should be on oral, chronic exposure of mammalian species at environmentally relevant concentrations. It is also suggested that future in vivo studies are conducted in parallel with studies on cells and tissues. In the light of the presented evidence, it is likely that cyanotoxins do not constitute a major risk to cardiovascular health under ordinary conditions met in everyday life. The risk of illnesses in other organs, in particular the liver, is higher under the same exposure conditions. However, adverse cardiovascular effects can be expected due to indirect effects arising from damage in other organs. In addition to risks related to extraordinary concentrations of the cyanotoxins and atypical exposure routes, chronic exposure together with co-existing diseases could make some of the cyanotoxins more dangerous to cardiovascular health.

Effect of Ascorbic Acid on Cardiac Surgery-Associated Acute Kidney Injury Incidence.

OBJECTIVES: Acute kidney injury (AKI) is associated with higher perioperative mortality and morbidity. Oxidative stress has been proposed as a cause of postoperative AKI. Ascorbic acid (AA) supplementation was suggested as a novel and promising antioxidant. The aim of this study was to evaluate the capability of AA to reduce the incidence of postoperative AKI in cardiac surgery patients. METHODS: A prospective randomized trial was conducted in patients scheduled for on-pump cardiac surgery. Subjects in the AA group received 2 g of AA intravenously during the induction of anesthesia, 2 g before aortic cross-clamp removal and 1 g every 8 hours for five postoperative days (the JERICA protocol). Postoperatively, the patients were monitored for AKI and other complications. Malondialdehyde levels were monitored in a subpopulation of 100 patients to evaluate the effect of AA on oxidative stress level. RESULTS: The AA and control group consisted of 163 and 169 patients, respectively. The groups were well matched for baseline demographics and had similar intraoperative characteristics. The incidence of AKI in the AA and control group was 20.9 and 28.4%, respectively (p = 0.127). The estimated glomerular filtration rate did not differ between the study groups in the entire postoperative period. There was a trend toward higher malondialdehyde values with statistical significance on postoperative day 1 and lower in-hospital mortality in the AA group (0.6 vs. 4.1%, p = 0.067). CONCLUSION: Our results do not support the effectiveness of AA supplementation in reducing the incidence of postoperative AKI in on-pump cardiac surgery patients. CLINICAL REGISTRATION NUMBER: This study was registered with the ISRCTN Registry under the trial registration number ISRCTN98572043.

Management of mechanical aortic valve thrombosis during the first trimester of pregnancy.

BACKGROUND: Cardiovascular diseases are the leading cause of morbidity and mortality in pregnant women. On the other hand, cardiac surgery is not so common for pregnant women. CASE REPORT: We present the case of a pregnant woman with diagnosed thrombosis of the mechanical aortic valve in the 12th gestational week. The patient underwent surgery, and successfully completed her pregnancy till the 37th gestational week. CONCLUSION: We showed that, despite general anaesthesia during the first trimester of pregnancy, the application of the nonpulsatile flow of extracorporeal circulation and mild hypothermia, the operation was successfully completed and that both mother and fetus survived.

ACUTE KIDNEY INJURY AFTER OPEN-HEART SURGERY PROCEDURES.

Cardiac surgery-associated acute kidney injury (CS-AKI) is a major complication associated with increased morbidity and mortality. There are multiple diagnostic criteria for CS-AKI. Despite many new investigations available for improved AKI diagnostics, creatinine and urea remain the cornerstone of diagnostics in everyday clinical practice. There are three major pathophysiological mechanisms that contribute to kidney injury, i.e. renal hypoperfusion, inflammation with oxidative stress, and use of nephrotoxic agents. Some risk factors have been identified that can be modified during the course of treatment (use of nephrotoxic agents, duration of cardiopulmonary bypass, type of extracorporeal circulation, postoperative low cardiac output or hypotension). The aim of AKI prevention should always be to prevent aggravation of renal failure and, if possible, to avoid progression to renal replacement therapy, which in turn brings worse long-term outcomes.

Déjà vu: is your patient a twin?

Coronary artery disease is the leading cause of death worldwide. Hereditary and environmental factors have a strong impact on coronary artery disease development. The exact incidence of this disease and its characteristics among identical twins is unknown. Despite a limited amount of documented cases, several characteristics can be drawn: coronary artery disease is expressed at an early age, the onset of symptoms occurs within a short time span between the twins, the coronary pathology is often very similar and the metabolic and biochemical profiles are generally alike. We present a case of identical male twins with a near simultaneous clinical presentation of coronary artery disease, who initially underwent unsuccessful percutaneous coronary intervention due to chronic total occlusion and finally, coronary artery bypass grafting. In the case of identical twins, it is imperative to aggressively screen the asymptomatic twin of the symptomatic patient irrespective of young age or absence of symptoms.

Closure of an atrial septal defect with a one-way flap patch in a patient with severe pulmonary hypertension.

An isolated atrial septal defect (ASD) can occasionally go unrecognized for decades and accounts for 25-30% of congenital heart disease cases diagnosed in adulthood. Pulmonary hypertension often develops as a result of a long-lasting, left-to-right shunt and may ultimately be associated with a fixed increase of pulmonary vascular resistance, sometimes rendering these patients inoperable. To reduce the risk of developing postoperative morbidity and possible mortality, we employed our technique of a unidirectional valved patch for the closure of ASD.

Development of cardiopulmonary bypass ­ A historical review.

The idea of isolated organ perfusion, a precursor of cardiopulmonary bypass, came by Legalois in 1812. First isolated organ perfusion was described by Loebell in 1849. The first closed system for oxygenation and returning the blood through arteries was created by Frey and Gruber in 1885. Gibbon Jr. is considered the father of extracorporeal circulation. In spring of 1934 he began constructing a machine for extracorporeal circulation in Boston. He published the first description of this system in 1937. Gibbon won the grant of the International Business Machines Corporation for developing the machine in 1947. Together they developed Model I in 1949 and Model II in 1951. After a few unsuccessful attempts in 1952, the first successful surgical intervention on the heart (closure of atrial septal defect) using cardiopulmonary bypass was performed on May 6, 1953. In 1945, Kirklin and his working group reported on a series of eight successfully treated patients in a row who underwent surgery with extracorporeal circulation. First successful valve surgery under the direct vision was performed by Dodrill in 1952, using his "Michigan Heart" machine as a right heart bypass. Using cardiopulmonary bypass, cardiac surgeons can deal with the complex cardiac pathology and save millions of lives.

Surgical treatment of intramural hematoma of the ascending aorta.

INTRODUCTION: Intramural hematoma of the aorta presents potentially fatal condition developing as a result of a vasa vasorum rupture. It is a major risk factor for developing a frank aortic dissection. CASE OUTLINE: A 65-year-old woman was admitted to our clinic for the second time, after her symptoms of chest pain and vertigo (with no electrocardiographic signs of myocardial infarction) hadn't disappeared after several months of medicament treatment (indicated in the first hospitalization). Computed tomography arteriography of the aorta showed no sign of acute aortic dissection, but revealed a contrast depo in the aortic wall of 8 x 14 mm dimensions, with no extravasation of contrast. Also, massive pericardial effusion was observed (10-30 mm in thickness). Transesophageal echocardiography confirmed these findings completely. The patient underwent surgery, in which plaque exulceration was detected on the convex side of the ascending aorta, 3 cm above the aortic valve, 1 cm in diameter, with no signs of intimal tear. A resection of the ascending aorta was performed, and the aorta was reconstructed with a 30 mm Dacron tube graft. The patient was discharged on the 14th postoperative day with satisfactory results. CONCLUSION: Intramural hematoma is not a common event, but it is potentially a fatal one. Open surgery in patients with an intramural hematoma is an effective treatment strategy, although percutaneous endovascular treatment options are being described.

[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.

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.

[Long term survival and quality of life after myocardial revascularization with respect to age and sex distribution].

INTRODUCTION: Quality of life assessment and survival analysis are a "gold standard" in assessing treatment quality in general. In the absence of a universally accepted integral index, we developed our own QOLi-NS (Quality of Life Index--Novi Sad) as a disease specific index. The aim of this study was to investigate long-term survival and quality of life after myicardial revascularization with respect to sex and age. MATERIAL AND METHODS: The study included 563 coronary patients operated on at the University Clinic of Cardiovascular Surgery in Sremska Kamenica, in the period from September 1, 1995 to June 1, 1998. The patients were devided into two groups with respect to sex and age; two age categories were defined: younger and older than 65 years of age. Quality of life was evaluated using Integral Quality of Life Index QOLi-NS. Actuarial life table was used to establish the survival curve. RESULTS: After myocardial revascularization, all investigated patients demonstrated a considerable improvement in quality of life with statistically significant differences with respect to age and sex. The highest postoperative quality of life (QOLi-NS), and the best survival rate were found in male patients and in patients younger than 65 years. CONCLUSION: The gathered data confirmed a significant improvement in quality of life and survival rate after myocardial revascularization in all groups of patients. A statistically significant difference in survival rate was determined with respect to the patients age. Improved quality of life in patients older than 65 years proved that myocardial revascularization is a good therapeutic option for these patients.