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Spyros Deftereos

Publications and source records attributed to Spyros Deftereos.

14 recordsLinked to original sources
PubMed2006

Aortic valve replacement in a patient with thalassemia intermedia.

Pseudoxanthoma elasticum-like diffuse elastic tissue defects and hypercoagulability are two well-established features in beta-thalassemia, which play a key role in the development of a spectrum of collateral complications in these patients. We present here a middle-aged thalassemia intermedia patient with severe aortic stenosis caused by heavy calcification of the valve, a hallmark of pseudoxanthoma elasticum. The patient underwent a successful replacement of the valve, which is the first such operation ever reported in these patients. However, rapid thrombosis leaded to failure of the mechanical valve, despite proper antithrombotic therapy.

Aortic Valve Stenosis↗
PubMed2005

Myelodysplastic syndrome associated with multiple autoimmune disorders.

The association between myelodysplastic syndromes (MDS) and autoimmune manifestations is not uncommon. As a rule, autoimmune abnormalities follow the diagnosis of MDS. We describe here a patient with MDS who developed a striking spectrum of diverse autoimmune disorders, including dermatitis, polyarthritis, and vasculitis, which preceded the clinical appearance of MDS.

Aged↗
PubMed2005

Cardiovascular effects of splenomegaly and splenectomy in beta-thalassemia.

Splenomegaly is common in beta-thalassemia, bearing some particular hemodynamic features, while splenectomy is an established therapeutic intervention in these patients. Their effects, however, on systemic hemodynamics and thalassemia heart disease have not yet been assessed. The study included 32 consecutive patients, 13 with thalassemia major (TM) and 19 with thalassemia intermedia (TI), aged 23.4+/-4.2 years, requiring splenectomy. Assessment was performed before and 6 months after splenectomy and included hematological profile and resting echocardiography; total blood volume was also measured in 10 of 32 cases. Preoperative echocardiographic data were compared with those of 34 controls. Preoperative left ventricular diameters and mass, cardiac index, and systolic pulmonary artery pressure were all significantly higher in patients compared to controls (p<0.001), but did not differ significantly between TM and TI patients. Postoperatively, the mean hemoglobin level increased from 8.1+/-0.6 to 9.1+/-0.4 g/dl (p<0.001), total blood volume index declined from 2847+/-332 to 2310+/-276 ml/m(2) (p<0.001), blood transfusions were discontinued in 80% of TI patients and mean 6-monthly transfusion requirements in TM patients were reduced from 28+/-5 to 22+/-4 units (p<0.001). However, cardiac parameters were not significantly modified. It seems that left ventricular remodeling, high output state, and increased pulmonary artery pressure characterize both TM and TI patients who require splenectomy. Although these abnormalities remain unchanged after splenectomy, the removal of the spleen may contribute to the prevention of further cardiac damage by ameliorating the patients' hematological status and reducing their transfusion needs.

Adult↗
PubMed2005

Identification of echocardiographic indices for the early detection of left-ventricular systolic dysfunction in beta-thalassaemia via Self-Organizing Maps: a data-exploration study.

Congestive heart failure (CHF) remains the primary cause of death in patients suffering from beta-thalassaemia major. Its early detection allows the prompt initiation of aggressive chelation therapy, when the condition can still be reversed. We aimed at identifying echocardiographic indices for the early detection of left ventricular (LV) systolic dysfunction, the physiological abnormality underlying CHF, in these patients. We used Self-Organizing Maps (SOMs)--an artificial neural network--for identifying novel correlations within our Electronic Healthcare Record (EHCR) database on beta-thalassaemia. We sought echocardiographic parameters that are correlated to future deterioration of the LV ejection fraction and therefore constitute early signs of LV systolic dysfunction. At the same time, we evaluated SOMs as tools for exploring clinical datasets and make recommendations on the setup of the SOM algorithm that is appropriate for such tasks. We found that high values of the LV end-systolic diameter index and of the E/A ratio are early indications of LV systolic dysfunction. From a technical point of view, zero-mean unit-variance normalization of the input data, a large initial neighbourhood radius and a rectangular SOM grid produced optimal maps for the purpose of detecting clinical correlations. We have successfully used SOMs for exploring a clinical dataset and for creating novel medical hypotheses. A clinical study has been launched to confirm these hypotheses, and initial results are encouraging.

Adult↗
PubMed2005

Technical guidelines for enhancing privacy and data protection in modern electronic medical environments.

Raising awareness and providing guidance to on-line data protection is undoubtedly a crucial issue worldwide. Equally important is the issue of applying privacy-related legislation in a coherent and coordinated way. Both these topics gain extra attention when referring to medical environments and, thus, to the protection of patients' privacy and medical data. Electronic medical transactions require the transmission of personal and medical information over insecure communication channels like the Internet. It is, therefore, a rather straightforward task to capture the electronic medical behavior of a patient, thus constructing "patient profiles," or reveal sensitive information related to a patient's medical history. The consequence is clearly a potential violation of the patient's privacy. We performed a risk analysis study for a Greek shared care environment for the treatment of patients suffering from beta-thalassemia, an empirically embedded scenario that is representative of many other electronic medical environments; we capitalized on its results to provide an assessment of the associated risks, focusing on the description of countermeasures, in the form of technical guidelines that can be employed in such medical environments for protecting the privacy of personal and medical information.

Computer Communication Networks↗
PubMed2005

Does heterozygous beta-thalassemia confer a protection against coronary artery disease?

Six hundred and thirty-eight patients who presented with clinical symptoms and/or electrocardiographic findings suggestive of stable angina pectoris were studied; they were also investigated by coronary arteriography. Hemoglobin electrophoresis was performed on all patients to detect the presence of the beta-thalassemia trait. Results were analyzed by logistic regression analysis to determine whether the latter confers any protective effect against advanced coronary artery disease (aCAD; defined as the presence of atheromas in coronary arteries, resulting in stenosis at least 70%). The role of the currently accepted risk factors (smoking, hypertension, hypercholesterolemia, and diabetes) in developing aCAD were reconfirmed, while at the same time it was found that beta-thalassemia heterozygosity is associated with a reduced risk against aCAD (odds ratio 0.39, 95% confidence interval 0.16-0.98). The lipoprotein and blood rheology profile of these individuals may be the underlying causes of this protective effect.

Aged↗
PubMed2005

Thalassemia heart disease: a comparative evaluation of thalassemia major and thalassemia intermedia.

BACKGROUND: Heart disease represents the main determinant of survival in beta-thalassemia, but its particular features in the two clinical forms of the disease, thalassemia major (TM) and thalassemia intermedia (TI), are not completely clarified. METHODS: We compared clinical and echocardiographic global parameters in 131 TM patients who received regular chelation transfusions and were highly compliant with treatment (mean age, 28 +/- 6 years [+/- SD]), and 74 age-matched, TI patients who did not receive chelation transfusions. RESULTS: Congestive heart failure was encountered in five patients with TM (3.8%; age range, 25 to 29 years) and in two patients with TI (2.7%; age range, 37 to 40 years). Systolic left ventricular (LV) dysfunction (ejection fraction < 55% or shortening fraction < 35%) was only encountered in patients with TM (8.4%). Considerable pulmonary hypertension (systolic tricuspid gradient > 35 mm Hg) was only present in TI (23.0%). In the remaining patients without evident heart disease, cardiac dimensions, LV mass, LV shortening and ejection fractions, and cardiac output were significantly higher in patients with TI. LV afterload was higher in patients with TM. LV diastolic early transmitral diastolic peak flow velocity (E)/late transmitral diastolic peak flow velocity (A) ratio was also higher in TM. Systolic and mean pulmonary artery pressures and total pulmonary resistance were higher in both young and old TI patients. CONCLUSION: Regular lifelong transfusion and chelation therapy in TM prevented premature heart disease and pulmonary hypertension, although LV dysfunction still occurred and led to heart failure. The absence of regular therapy in TI, in contrast, preserved systolic LV function but allowed pulmonary hypertension development, which also led to heart failure, starting within the fourth decade of life, a decade later compared to TM.

Adult↗
PubMed2004

Hemodynamic assessment of splenomegaly in beta-thalassemia patients undergoing splenectomy.

Splenomegaly is a common finding in beta-thalassemia; however, its hemodynamic features and its potential correlations with high output state and hepatic disorders, both also frequent in thalassemia, have not yet been assessed in these patients. Eight beta-thalassemia patients with the indication for splenectomy and no symptoms or signs of heart disease, aged 25.6+/-5.5 years, were studied. Preoperative assessment included hematological profile, liver biology, hepatitis virus serology, and echocardiography. During splenectomy, splenic artery blood flow and splenic vein pressure were directly measured and liver biopsies were taken. Preoperative echocardiographic data were compared with those of 34 healthy controls. The preoperative cardiac index was significantly elevated in patients (4.8+/-1.3 vs 3.4+/-1.1 l/min per m2 in controls, p<0.001). Splenic blood flow, although increased, was not particularly high, being 285+/-56 ml/min or 0.13+/-0.04 ml/min per g of splenic mass, representing 4.1+/-0.9% of total cardiac output (CO). Splenic vein pressure was considerably elevated (29.7+/-5.5 cmH2O). Hepatic fibrosis, iron deposition, and extramedullary foci were found in all eight biopsies. Serology was positive in five of eight cases. beta-thalassemia patients with extensive splenomegaly requiring splenectomy are characterized by high output state, increased splenic blood flow, which probably makes a limited contribution to CO elevation, and portal hypertension, manifest by increased splenic vein pressure and hepatic histopathological abnormalities.

Adolescent↗
PubMed2004

Rupture of chordae tendineae in patients with beta-thalassemia.

Cardiac disease is the primary cause of mortality in beta-thalassemia patients. Except for ventricular dysfunction and pulmonary hypertension that represent the main forms of heart disease in these patients, valvular abnormalities including valvular regurgitation, endocardial thickening and calcification and mitral valve prolapse have also been described. Here we present two patients with thalassemia major and mitral chordal rupture, a previously undescribed abnormality in this population. Pathogenesis of this finding may involve thalassemia-related pseudoxanthoma elasticum-like syndrome, a diffuse elastic tissue defect, which is observed with a notable frequency in these patients and has been associated with numerous cardiovascular complications, including valvular ones.

Adult↗
PubMed2004

Systems literature analysis.

Systems literature analysis (SLA) is the literature-driven version of systems biology. It treats collections of scientific literature as a system of millions of interconnections between research parameters, such as genes, diseases, tissues, cell events, model organisms, experiment types, and reagents. SLA aims to replace the traditional keyword-based querying of literature databases, which return sorted lists of papers, with a systems-based approach that returns integrated networks of relationships. Major applications include literature-based discovery of novel targets that link, for example, previously unlinked diseases and phenotypes to common genes and cellular events, and experiment design.

Databases, Bibliographic↗
PubMed2004

Cardiovascular adaptation to chronic anemia in the elderly: an echocardiographic study.

OBJECTIVE: To study the effects of chronic severe anemia on the aging heart. METHODS: We studied 41 elderly patients (mean age 69.8 yr, standard deviation [SD] 3.9 yr) suffering from chronic severe anemia (mean hemoglobin 6.3, SD 0.5 g/dL) with no history of cardiac disease, along with 63 healthy age- and sex-matched controls. Assessment included physical examination, electrocardiogram and Doppler echocardiography. RESULTS: Although heart rates were similar between patients and controls, arterial blood pressures were significantly lower in patients (mean pressure 92.7 mm Hg, SD 7.9, v. mean 102.1 mm Hg, SD 3.5; p < 0.001). No patient was found to have congestive heart failure. Patients with chronic anemia had larger diameters of the left (end-systolic 35.28, SD 4.20, v. 33.73, SD 2.08 mm, p < 0.05; end-diastolic 53.33, SD 4.55, v. 50.37, SD 2.10 mm, p < 0.001) and right ventricles (30.76, SD 3.98, v. 29.04, SD 2.04 mm; p < 0.05), and greater left-ventricular mass (277.64, SD 62.85, v. 212.91, SD 24.87 g; p < 0.001). Fractional shortening did not differ significantly (0.33, SD 0.04, v. 0.33, SD 0.03). The load-independent end-systolic index was lower in patients (2.67, SD 0.56, v. 3.87, SD 0.49 kdyn x m2/cm5; p < 0.001) along with end-systolic stress and total systemic resistance (p < 0.001) than controls, whereas the cardiac index was higher (4.31, SD 1.29, v. 2.73, SD 0.51 L/min/m2; p < 0.001). Differences between the 2 groups in diastolic function indices and pulmonary arterial pressures were not statistically significant. INTERPRETATION: Chronic severe anemia is well tolerated by the aging heart. Neither congestive heart failure nor clearly evident left-ventricular dysfunction were encountered. The heart exhibited an adaptive potential through remodelling by means of the Frank-Starling mechanism and afterload reduction. However, the lower end-systolic index in patients suggests that ventricular performance was marginally compromised. This state of high output was achieved mainly by increased stroke volume, with little contribution from heart rate.

Adaptation, Physiological↗
PubMed2004

Hypoparathyroidism and heart failure in thalassemic patients: a case report.

Hypocalcemic cardiomyopathy due to primary or secondary hypoparathyroidism is usually refractory to conventional treatment for cardiac failure but responds favorably to the restoration of normocalcemia. We report on a thalassemic patient with severe cardiac failure due to hypocalcemia. Cardiac echocardiography showed impaired biventricular performance and laboratory analyses revealed hypoparathyroidism due to hemosiderosis. Concomitant treatment for heart failure and calcium supplementation was initiated. Thereafter, clinical and laboratory improvement was achieved. In the literature of thalassemic disorders, this is the first case of heart failure associated with hypoparathyroidism in which the patient recovered significantly after the correction of hypocalcemia, providing strong evidence to support our hypothesis of hypocalcemic myocardiopathy.

Adult↗
PubMed2003

Unstable angina associated with coronary arterial calcification in a thalassemia intermedia patient with a pseudoxanthoma elasticum-like syndrome.

The coexistence of a pseudoxanthoma elasticum (PXE)-like syndrome in beta-thalassemia and other hemoglobinopathies is a recently established clinical entity that has been observed with a significant frequency and related to some severe, even life-threatening complications. We present here a thalassemia intermedia patient who developed unstable angina in a setting of severe anemia and PXE-related coronary arterial calcification. Besides the clinical significance of this PXE-like syndrome, its acquired nature may introduce some new thoughts regarding the pathogenesis of atherosclerosis.

Anemia↗