Huseyin Oflaz

Istanbul University, İstanbul, Istanbul, Turkey

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Publications (68)194.75 Total impact

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    Article: Decrease in endothelial progenitor cells associated with inflammation, but not with endothelial dysfunction in chronic hemodialysis patients.
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    ABSTRACT: Introduction: Endothelial progenitor cells (EPC), bone marrow derived cells, are considered to have a pivotal role in maintaining the integrity and repair of the endothelium. Endothelial dysfunction, atherosclerosis and inflammation are implicated for increased CV mortality in uremia. In this study, we aimed to investigate the possible association of EPC with inflammation, endothelial dysfunction and atherosclerosis in chronic hemodialysis (HD) patients. Patients and methods: 67 HD patients (male/female: 30/37, mean age: 58 ± 15 years) and 22 healthy controls (male/female: 13/9; mean age: 48 ± 8 years) were included. EPC were cultivated in the fibronectin-covered culture dishes and counted. Also EPC markers were studied by flow cytometry using anti-CD34, anti-CD133 and anti-vascular endothelial growth factor receptor 2 (VEGFR-2) antibodies. Serum levels of IL-6, TNF-α, intercellular cell adhesion molecule (ICAM), vascular cell adhesion molecule (VCAM) and asymmetric dimethyl-arginine (ADMA) were measured by ELISA method. Endothelial function was investigated by measuring flow-mediated dilatation (FMD) of the brachial artery. Carotid intima-media thickness (CIMT) and ratio (CIMR) were also examined. Results: EPC number was decreased in HD patients when compared to controls (63.7 ± 8.9 vs. 101.5 ± 19.6/ high power field, p < 0.001). Also CD34+ cell count was significantly lower in the HD group (2.26 ± 3.52 vs. 6.03 ± 4.73%, p < 0.0001). EPC number was significantly inversely correlated with serum TNF-α levels in HD patients(r: -0.453, p < 0.001) and also in the control group (r = -0.509, p = 0.044). There was an inverse association between VEGFR-2+/CD34+cell count and serum IL-6 levels (r: -0.364, p = 0.006) in HD patients. However, EPC count was not related to FMD and CIMT/CIMR. In HD patients, there was a positive correlation between serum IL-6 levels with CIMT (r = 0.358, p = 0.01) and CIMR was positively correlated with serum ICAM (r = 0.430, p = 0.002). Conclusion: EPC number was decreased in uremia and was associated with inflammation. TNF-α might have specific inhibitory actions on EPC in both HD patients and healthy controls. No relationship was present between EPC and endothelial dysfunction/atherosclerosis.
    Clinical nephrology 08/2012; · 1.17 Impact Factor
  • Article: Reduction of uric acid levels with allopurinol treatment improves endothelial function in patients with chronic kidney disease.
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    ABSTRACT: Endothelial dysfunction (ED) is a key event in the development of atherosclerotic cardiovascular disease (CVD) in patients with chronic kidney disease (CKD). Association of hyperuricemia with CVD has been previously reported in the nonuremic population. In this prospective study, we aimed to evaluate the effects of treatment of hyperuricemia with allopurinol on ED and changes in the serum reactive oxygen species in patients with CKD. In this study, 19 (13 male) hyperuricemic (UA > 7 mg/dl) nondiabetic CKD patients without any comorbidity, aged < 60 years with creatinine clearance (CrCl) between 20 and 60 ml/min were evaluated. Endothelial functions were assessed by ischemia-induced forearm vasodilatation method (EDD). Oxidative stress was evaluated by measuring the serum oxidized LDL (ox-LDL), advanced oxidation protein products (AOPP) and nitrotyrosine (NT) levels. After measuring all these tests at baseline, allopurinol therapy was commenced for 8 weeks. After 8 weeks of allopurinol treatment, all measurements were repeated. Then, allopurinol treatment was ceased and same measurements were also repeated 8 weeks after ceasing of the treatment. Serum creatinine, total cholesterol, albumin, hs-CRP, CrCl and proteinuria levels of the patients were similar among three study periods. After allopurinol therapy, the mean serum UA and NT levels significantly reduced as compared to baseline. At the 8th week after cessation of allopurinol treatment, serum UA levels were significantly increased. After allopurinol therapy, EDD value increased from 5.42 ± 8.3% at baseline to 11.37 ± 9% (p < 0.001). At the 8th week after ceasing allopurinol treatment, EDD returned to baseline values (5.96 ± 8%, p < 0.001). Treatment of hyperuricemia with allopurinol improve ED in patients with CKD. However, mechanism responsible for this beneficial effect seems to be apart from antioxidant effects of allopurinol.
    Clinical nephrology 04/2012; 77(4):275-82. · 1.17 Impact Factor
  • Article: Intrarenal application of N-acetylcysteine for the prevention of contrast medium-induced nephropathy in primary angioplasty.
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    ABSTRACT: Contrast medium-induced nephropathy (CIN) is a well-known complication of coronary angiographic procedures, especially in patients treated with primary angioplasty. To prevent CIN, we examined using a local application of N-acetylcysteine (NAC) for the prevention of CIN during primary angioplasty. We hypothesized that a local application of NAC into the renal arteries would provide the benefit of a higher local concentration, lower first-pass metabolism, and faster efficacy. To evaluate the effects of NAC by the intrarenal route, we performed a prospective, randomized clinical study in patients with acute myocardial infarction treated with primary angioplasty. Participants were 312 patients with ST-segment elevation myocardial infarction undergoing primary angiography. Eligible patients were randomly assigned to receive intravenous NAC, intrarenal NAC, or placebo. Overall, CIN occurred in 74 (23.7%) of the 312 patients. The rate of CIN was 25% in the intravenous NAC group, 22.9% in the intrarenal NAC group, and 23.2% in the placebo group, with no significant effect seen for either treatment (P=0.64). We did find a significant correlation between CIN and ejection fraction (P=0.05) and baseline renal function (P=0.01). Both intrarenal and intravenous applications of NAC failed to show any benefit over placebo in the prevention of CIN. This result shows that NAC application does not have any prophylactic effect, dose dependent or otherwise, on CIN, as previously reported. Our results suggest that more attention should be paid to optimize hemodynamic variables for the prevention of CIN.
    Coronary artery disease 02/2012; 23(4):265-70. · 1.56 Impact Factor
  • Article: The preoperative cardiology consultation: goal settings and great expectations.
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    ABSTRACT: Despite the availability of guidelines for preoperative cardiology consultations, their efficacy in real clinical practice remains unknown. Furthermore, there are concerns that overused cardiology consultations can lead to unnecessary investigations, prolonged hospital stays, and even cancellation of necessary surgery. In this retrospective study, we investigated: (i) the potential impact of the American Heart Association/American College of Cardiology algorithm and (ii) the potential of this algorithm for preventing unnecessary evaluation. We examined the cardiology consultation requests for 712 patients scheduled for elective surgery. Our analysis included: (i) patient characteristics, (ii) abnormalities revealed by the consultant, (iii) impact of these abnormalities on clinical decision making and therapy modification. The most common reason for consultation was 'pre-operative evaluation' (80.9%). Although our cardiologists revealed an abnormality in 67.8% and recommended further work up in 58.7% of our patients, they contributed to the clinical course in only 36.9%. Moreover, when the algorithm was applied to 'routine pre-operative evaluation' requests lacking a specific question, only 7.6% of these consultation requests required further investigation. Preoperative cardiology consultation seems to be overused. Although the fear of missing important issues leads surgeons to use a decreased threshold for pre-operative consultation requests, such a non-specific manner of pre-operative consultation request causes unnecessary investigations and decreased cost-effectiveness. Furthermore, the detection of any clinical abnormality by cardiologists surprisingly adds little to clinical decision making.
    Acta cardiologica 08/2011; 66(4):447-52. · 0.61 Impact Factor
  • Article: Hypervolemia rather than arterial calcification and extracoronary atherosclerosis is the main determinant of pulse pressure in hemodialysis patients.
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    ABSTRACT: Pulse pressure (PP) has been reported as an independent predictor of cardiovascular mortality in hemodialysis patients. In this study, we aimed to investigate association of PP with echocardiographic and vascular structural changes such as atherosclerosis and arterial calcifications in HD patients. In this cross-sectional study, 108 chronic hemodialysis patients (49 male, 59 female, mean age: 46 ± 13 years) were included. Biochemical analyses, echocardiographic and high-resolution carotid Doppler examinations were done. Aortic wall and coronary artery calcifications were measured with electron beam computed tomography. The degree of carotid artery stenosis was measured at four different sites (communis, bulbus, interna and externa) in both carotid arteries. PP was strongly correlated with systolic (r: 0.82) and diastolic (r: 0.33) blood pressure, left ventricular mass index (r: 0.58), left ventricle end diastolic diameter (r: 0.38) and weakly correlated with aortic wall calcification score (r: 0.26) and carotid plaque score (r: 0.27), but not with coronary artery calcification score. Patients with carotid plaque had higher PP than patients without plaque (50 ± 16 mmHg versus 44 ± 14 mmHg, P = 0.05). Patients were divided into three groups according to aortic wall calcification score. PP was significantly higher in patients with higher aortic wall calcification (54 ± 16 mmHg) than patients with lower aortic wall calcification (44 ± 15 mmHg, P = 0.04). However, on multivariate linear regression analysis for predicting PP, the only significant factor retained was left ventricle end diastolic diameter. PP was weakly associated with large vessel calcification and atherosclerosis in hemodialysis patients. The bulk of the effect on PP seems to be due to hypervolemia.
    International Urology and Nephrology 07/2011; 44(4):1203-10. · 1.47 Impact Factor
  • Article: Circulating vaspin levels and epicardial adipose tissue thickness are associated with impaired coronary flow reserve in patients with nonalcoholic fatty liver disease.
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    ABSTRACT: Patients with nonalcoholic fatty liver disease (NAFLD) have a reduced coronary flow reserve (CFR) and an increased risk of cardiovascular disease. The fat cells that surround coronary arteries may play a central and underrecognized role in development of cardiovascular disease through the systemic secretion of adipokines. We therefore evaluated the relation of epicardial fat thickness, serum levels of epicardial fat-related adipokines (chemerin and vaspin), and CFR in patients with NAFLD. We investigated 54 patients with biopsy-proven NAFLD and 56 age- and sex-matched controls. CFR and epicardial fat thickness (EFT) were measured by transthoracic echocardiography. Serum levels of chemerin and vaspin were measured by ELISA. EFT was significantly higher (0.64 ± 0.13 vs. 0.54 ± 0.10 cm, P<0.001) and CFR significantly lower (2.11 ± 0.45 vs. 2.52 ± 0.62, P < 0.001) in patients with NAFLD than in controls. Serum levels of vaspin and chemerin were both significantly increased in patients with NAFLD compared with controls. Stepwise regression analysis showed that EFT (β=-0.53, t=-3.7, P<0.001), serum vaspin levels (β=-0.30, t=-2.5, P=0.014), and liver fibrosis (β=-0.31, t=-2.11, P=0.041), in the order they entered into the model, were independent predictors of CFR in NAFLD patients. Our data suggest the presence of a complex interplay between EFT, serum vaspin, and liver histology in promoting an impaired hyperemic stimulation of coronary blood flow in patients with NAFLD.
    Atherosclerosis 03/2011; 217(1):125-9. · 3.79 Impact Factor
  • Article: Effect of cigarette smoking on platelet aggregation.
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    ABSTRACT: Cigarette smoking may increase platelet aggregation and cause atherothrombotic cardiovascular events. We aimed to investigate the impact of cigarette smoking on platelet function in patients with ischemic coronary heart disease (CHD). Twenty patients with ischemic stable CHD under aspirin therapy (300 mg/d), who continue to smoking despite all warnings, and 20 nonsmokers with CHD are enrolled in the study. Platelet function is studied at the morning, before and 15 minutes after the first cigarette, by the Platelet Function Analyzer (PFA)-100, with collagen and epinephrine and collagen and adenosine diphosphate cartridges. Post aspirin platelet hyperactivity is defined as having a closure time (CT) shorter than 186 seconds despite regular aspirin intake. Serial CT measurements are analyzed by paired samples t test. Persistent platelet activity was present in 4 smoker (20%) and 3 nonsmoker (15%) patients at the beginning. Platelet activity measured by the PFA-100 is been increased significantly after cigarette smoking (P = .004). Shorter CTs were determined after smoking in all patients with and without baseline persistent platelet activity, and 4 more participants became aspirin nonresponder (P = .004). No significant differences in demographic, hematological, and biochemical parameters were determined between aspirin responders and nonresponders. We determined that cigarette smoking may increase platelet aggregation in patients with ischemic CHD in an aspirin nonresponsive manner. Our results emphasize the importance of quitting cigarette smoking in patients with CHD.
    Clinical and Applied Thrombosis/Hemostasis 03/2011; 17(6):E175-80. · 1.33 Impact Factor
  • Article: Folic Acid and vitamin B12 supplementation improves coronary flow reserve in elderly subjects with vitamin B12 deficiency.
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    ABSTRACT: Major cardiovascular risk factors including hyperhomocysteinemia are frequently associated with decreased coronary flow reserve (CFR), an important physiological parameter of the coronary circulation. This study was designed to determine whether folate (5 mg) and vitamin B12 (500 μg) supplementation in elderly patients with vitamin B12 deficiency improved CFR, while reducing homocysteine levels. Forty-four patients aged >65 years showing serum vitamin B12 concentrations <180 mg/dL were randomized to take either oral folate (5 mg) plus vitamin B12 (500 μg) supplementation (n = 24) or placebo (n = 20) for 8 weeks. The study course consisted of two visits: visit 1 (pretreatment) included the baseline assessment of laboratory profile and CFR values with trans-thoracic Doppler echocardiography. Visit 2 was scheduled 8 weeks later to repeat CFR and laboratory tests after therapy. In the treatment arm, oral supplementation with folate and vitamin B12 significantly improved total cholesterol, serum folate, serum vitamin B12, homocysteine, and insulin resistance. At 8 weeks, the treatment group had a significant increase from baseline in CFR values (baseline: 1.7 ± 0.2; postttreatment: 2.1 ± 0.2, p <0.001) that was not seen in the placebo group (baseline: 1.6 ± 0.2; posttreatment: 1.6 ± 0.2; P = ns). In this study of elderly subjects with vitamin B12 deficiency, supplementation with folate and vitamin B12 was associated with a significant improvement in CFR values.
    Archives of medical research 07/2010; 41(5):369-72. · 1.88 Impact Factor
  • Article: Improvement of coronary flow velocity reserve with telmisartan in patients with autosomal-dominant polycystic kidney disease.
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    ABSTRACT: Endothelial dysfunction (ED) has been reported in patients with autosomal-dominant polycystic kidney disease (ADPKD). Coronary flow velocity reserve (CFVR) is a noninvasive test showing endothelial function of epicardial coronary arteries and coronary microcirculatory function. The aim of this study was to investigate the effect of the angiotensin receptor blocker, telmisartan, on CFVR in patients with ADPKD. Thirteen patients with ADPKD and well-preserved renal function and 22 healthy controls were included in the study. CFVR was measured at baseline and after dipyridamole infusion by echocardiography. CFVR was calculated as the ratio of hyperemic to baseline average peak diastolic velocities. After the baseline evaluation of CFVR, patients started telmisartan at a dose of 80 mg/day and were followed for 12 months. CFVR was remeasured after 6 and 12 months of therapy. Patients with ADPKD had significantly lower CFVR compared to healthy subjects. CFVR increased significantly after 6 months and 12 months of telmisartan therapy (P = 0.001) in patients with ADPKD. One year of telmisartan therapy significantly improved CFVR in patients with ADPKD. This finding suggests that the stimulation of the renin-angiotensin-aldosterone system contributes to the ED in these patients.
    Southern medical journal 04/2010; 103(5):409-13. · 0.92 Impact Factor
  • Article: Coronary artery calcification and coronary flow velocity in haemodialysis patients.
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    ABSTRACT: Decreased coronary flow reserve (CFR) is a marker of endothelial dysfunction, coronary artery calcification and inflammation, well-known cardiovascular risk factors in haemodialysis (HD) patients. In this study, we aimed to investigate the correlation of coronary artery calcification scores (CACS) with CFR in HD patients. Sixty-four end-stage renal failure patients were enrolled in this study (38 males, 26 females). Thirty-nine healthy subjects (22 males, 17 females) were included in the control group. Biochemical parameters and acute-phase inflammation marker [high-sensitivity C-reactive protein (hs-CRP)] of patients were recorded before dialysis. The CACS were measured by electron beam computerized tomography method. CFR recordings were performed by trans-thoracic Doppler echocardiography. The relationship between CACS and CFR was evaluated. The mean CACS was 281 +/- 589 and 29 patients had CACS < 10. Patients with CACS > 10 had significantly lower CFR values compared to patients with CACS < 10 (1.56 +/- 0.38 vs 1.84 +/- 0.53, P = 0.024). However, there was no difference in hs-CRP values between the groups. CFR was negatively correlated with CACS (r = -0.276, P = 0.030). In multiple stepwise regression analysis, CACS was found to be an independent variable for predicting CFR (P = 0.048). During a follow-up of 18 months, 10 patients had experience of cardiovascular events. Patients with CACS > 10 had significantly higher event rate [34.5% (10/29) vs 0% (0/24)] compared to those with CACS < 10 (P = 0.001). Patients who developed cardiovascular events had significantly higher mean CACS and lower CFR values than the remaining group (P = 0.019 and P = 0.039). All of four patients who died during follow-up were in the CFR < 2 and CACS > 10 groups. CACS was associated with CFR in HD patients. However, we did not find any association of inflammation with CACS and CFR. This association between CFR and CACS might indicate two different (anatomical and functional) aspects of the common pathophysiology of the arterial system in HD patients.
    Nephrology Dialysis Transplantation 02/2010; 25(8):2685-90. · 3.40 Impact Factor
  • Article: Coronary flow reserve is impaired in patients with nonalcoholic fatty liver disease: association with liver fibrosis.
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    ABSTRACT: Nonalcoholic fatty liver disease (NAFLD) is associated with an increased risk of cardiovascular disease. Coronary flow reserve (CFR) is widely used to examine the integrity of coronary microvascular circulation. We evaluated the prevalence of impaired CFR in patients with biopsy-proven NAFLD. We also investigated the independent clinical, biochemical, and liver histology predictors of CFR in the setting of NAFLD. Fifty-nine consecutive patients with NAFLD and 77 age- and gender-matched controls were evaluated. CFR recordings were performed by transthoracic Doppler harmonic echocardiography. CFR>or=2.0 was considered normal. CFR was significantly lower in patients with NAFLD than in controls (2.11+/-0.45 vs. 2.52+/-0.62, P<0.001). An impaired CFR (i.e. <2) was found in 25 NAFLD patients (42.4%) whereas all controls had normal CFR values (P<0.001). A stepwise linear regression analysis in NAFLD patients identified liver fibrosis scores as the only independent predictor of CFR values (beta=-0.60; t=-2.44, P=0.021). Our findings indicate that in patients with biopsy-proven NAFLD: (a) an abnormal CFR is found in approximately 42.4% of cases, and (b) liver fibrosis scores are an independent predictor of depressed CFR.
    Atherosclerosis 02/2010; 211(1):182-6. · 3.79 Impact Factor
  • Article: Impact of genetic polymorphisms on platelet function and aspirin resistance.
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    ABSTRACT: Genetic polymorphisms may affect platelets' responses to the antiplatelet therapy. Our aim was to determine the role of genetic polymorphisms on aspirin resistance in patients with coronary heart disease (CHD). A total of 126 consecutive patients (35-85 years old, 32% women) with chronic stable CHD was enrolled in the study. Platelet function assays were realized by the platelet function analyzer (PFA)-100 with collagen and epinephrine (Col/Epi) and collagen and adenosine diphosphate (Col/ADP) cartridges. Aspirin resistance was defined as having a closure time of less than 186 s with Col/Epi cartridges despite regular aspirin therapy. Factor V, prothrombin, factor XIII, beta-fibrinogen, plasminogen activator inhibitor I (PAI-1), glycoprotein IIIa, methylene tetrahydrofolate reductase, ACE and ApoB gene polymorphisms were determined by three consecutive steps: isolation and amplification of DNA and reverse hybridization. We determined that 30 patients (23.8%) had aspirin resistance by the PFA-100. Mean closure time measured with the Col/ADP cartridges was 74 +/- 12 s (51-104 s). Ten of the 30 patients with aspirin resistance were women (33.3%). Genetic polymorphisms were determined in 30 aspirin-resistant and 17 aspirin-sensitive patients. No statistically significant relationship was determined between aspirin resistance and the genetic panel. In our study we did not determine a significant relationship between the aspirin resistance and factor V, prothrombin, factor XIII, beta-fibrinogen, PAI-1, glycoprotein IIIa, methylene tetrahydrofolate reductase, ACE and ApoB gene polymorphisms.
    Blood coagulation & fibrinolysis: an international journal in haemostasis and thrombosis 11/2009; 21(1):53-6. · 1.25 Impact Factor
  • Article: Endothelial dysfunction in hemodialysis patients with failed renal transplants.
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    ABSTRACT: Endothelial dysfunction (ED) is a common precursor and denominator of cardiovascular events including development of atherosclerosis. In this cross-sectional study, we aimed to investigate ED, measured by coronary flow reserve (CFR) in hemodialysis (nHD) patients who were never transplanted and patients with failed renal transplants restarting hemodialysis (fTx-HD). Forty nHD (24 males, mean age 39 ± 9 yr) and 43 fTx-HD patients (27 males, mean age 36 ± 9 yr) were included in the study. Clinical and biochemical parameters, including high-sensitive C-reactive protein (hs-CRP) levels were determined. Also, CFR measurements were used to evaluate ED. There were no significant differences regarding age, gender, smoking status, systolic and diastolic blood pressure levels, mean duration of HD treatment as well as Kt/V((urea)) values between the two groups. Time spent on dialysis in the nHD group and dialysis duration following failure of renal allograft in the fTx-HD group were similar. Serum creatinine, hemoglobin, hematocrit, calcium and phosphorus levels were similar between the two groups as well. When compared to nHD group, serum total cholesterol (139 ± 3 vs. 154 ± 3 mg/dL, p = 0.045), serum albumin (3.8 ± 0.3 g/dL vs. 4.1 ± 0.2 g/dL, p < 0.0001) and CFR (1.60 ± 0.2 vs. 1.75 ± 0.3, p = 0.028) levels were significantly lower, while serum hs-CRP levels (11 ± 15 mg/L vs. 3 ± 4 mg/L, p = 0.001) were significantly higher in the fTx-HD group. Serum hs-CRP negatively correlated (r = -0254, p = 0.021), while serum albumin positively correlated (r = 0402, p = 0.001) with CFR values. ED is more prominent in fTx-HD than the nHD patients. Inflammation, caused by failed renal allograft can be responsible for this abnormality.
    Clinical Transplantation 11/2009; 24(5):678-84. · 1.67 Impact Factor
  • Article: Left ventricular function by 'conventional' and 'tissue Doppler' echocardiography in paediatric dialysis patients.
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    ABSTRACT: Cardiovascular abnormalities are common in children with chronic kidney disease (CKD). Left ventricular (LV) structure and functions have been extensively studied by conventional pulse-wave Doppler echocardiography (cPWD), however, tissue Doppler imaging (TDI) is a relatively new echocardiography method. The aims of this study were to evaluate LV diastolic function in paediatric dialysis patients using cPWD and TDI methods, and to compare the findings obtained with two modalities. This study included 38 children and adolescents on dialysis (14 haemodialysis and 24 peritoneal dialysis, duration of dialysis 58.0 +/- 32.8 months) and 16 age- and sex-matched healthy subjects. The mean left ventricular mass index (LVMI) was significantly higher in the patient group (P < 0.001) and the most common cardiac geometry was concentric LV hypertrophy (55%). There was no significant difference in LV systolic function between patient and control groups. However, dialysis patients had worse LV diastolic function both according to cPWD (lower E/A ratio) and TDI (lower Em/Am ratio) than the healthy subjects (P < 0.001 and P = 0.001, respectively). Also, the index of LV filling pressure (E/Em ratio) obtained by the combination of cPWD and TDI was significantly higher in the patients (P < 0.001). Cumulative dose of calcium-based phosphate binder (CBPB), diastolic blood pressure and LVMI were the independent predictors of E/Em ratio. Our study shows that LV diastolic dysfunction is common in paediatric dialysis patients and TDI findings correlate well with cPWD findings. Similarly, higher dose intake of CBPB, hypertension and LV hypertrophy have a negative effect on LV filling pressure suggesting diastolic function.
    Nephrology 10/2009; 14(7):636-42. · 1.31 Impact Factor
  • Article: Endothelial function and endothelial nitric oxide synthase intron 4a/b polymorphism in primary hyperparathyroidism.
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    ABSTRACT: Patients with symptomatic primary hyperparathyroidism (pHT) have increased cardiovascular morbidity and mortality. Endothelial nitric oxide synthase (eNOS) intron 4a/b polymorphism is associated with coronary artery disease and hypertension in various populations. Our aim is to evaluate endothelial function in patients with pHT during pre-operative hypercalcemic and post-operative normocalcemic periods and to determine whether intron 4a/b polymorphism of eNOS gene influences endothelial function. Forty patients with pHT (age 48.48+/-11.64 yr) were examined pre-operatively and reexamined 5.8+/-1.9 months after parathyroidectomy. Forty-three healthy subjects (age 47.13+/-8.14 yr) were served as control group. Endothelial function was determined by flow-mediated dilation of brachial artery (FMD). eNOS4a/b polymorphism was detected by polymerase chain reaction. FMD was significantly lower in patients pre-operatively compared with controls (8.48+/-1.78% vs 19.49+/-2.34%, p<0.001). FMD improved significantly after parathyroidectomy (16.19+/-2.16%, p<0.001 compared with pre-operative measurements), but was still significantly lower than controls (p<0.001). The distribution of eNOS4a/b genotype frequencies was not significantly different between patients and controls. Logistic regression analysis showed that increased serum calcium (>2.47 mmol/l) and PTH concentrations (>7.75 pmol/l) were significant independent predictors of lower FMD (<16.7%). ENOS4a/b polymorphism did not enter in this model. Impaired endothelial function in patients with pHT improves after successful parathyroid surgery. No compelling data are evident to suggest that eNOS4a/b polymorphism modifies the endothelial function in patients with pHT.
    Journal of endocrinological investigation 08/2009; 32(7):611-6. · 1.57 Impact Factor
  • Article: Left ventricular thickness is increased in nonhypertensive Turner's syndrome.
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    ABSTRACT: Turner's syndrome (TS), the most frequent congenital anomaly in newborn girls, is associated with various cardiovascular abnormalities, predominantly bicuspid aortic valves and aortic coarctation. The causes of the left ventricular hypertrophy (LVH) and ECG findings associated with TS are unknown. We used echocardiography to assess cardiac structure and function in normotensive patients with TS. Thirty-one patients with TS and 30 healthy women were enrolled in this comparative study. Twelve-lead ECG, 24-hour-ambulatory ECG recording, and echocardiography were performed. With 24-hour-ambulatory ECG recording, the mean heart rate (HR) of TS women was higher than non-TS women. With echocardiographic examination, the interventricular septum diastolic thickness, left ventricle posterior wall diastolic thickness (LVPW), the LV mass index (LVMI), and left atrial diameter index (LADi) were significantly higher in TS women compared with controls. Mitral flow A velocity was significantly higher and the ratio of early to late diastolic filling was significantly lower in TS patients. HR, LV wall thicknesses, LVMI and the LADi are significantly increased in normohypertensive TS women. There is also subclinical diastolic dysfunction in these patients.
    Echocardiography 06/2009; 26(8):943-9. · 1.24 Impact Factor
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    Article: MR imaging features of ventricular noncompaction: emphasis on distribution and pattern of fibrosis.
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    ABSTRACT: The purpose of this study is to describe morphologic features and delayed contrast-enhancement pattern of the noncompaction of the left ventricle in cardiac magnetic resonance (MR) imaging. We retrospectively reviewed morphological cardiac MR imaging findings of ventricular noncompaction in 15 patients (eight men, seven women, and ages 6 months to 73 years old, mean 22 year). In 10 patients delayed contrast enhanced images were obtained after the morphological examination. In all patients, noncompaction was seen in the apical and midventricular-lateral segment. Basal-septal segment involvement was not determined in any patients. Noncompacted/compacted ratio was 2-4.5 (mean 3). In nine patients, right ventricular involvement was observed in addition to left ventricular noncompaction. Delayed contrast-enhancement was seen in eight out of 10 patients not only involved segments but also normal segments of the heart. Cardiac MR imaging is a valuable imaging method in patients with suspected ventricular noncompaction by showing increased trabeculations, deep intertrabecular recesses and fibrosis. Fibrosis is a common finding in ventricular noncompaction.
    European journal of radiology 04/2009; 74(1):147-51. · 2.65 Impact Factor
  • Article: Intraaortic balloon occlusion during refractory cardiac arrest. A case report.
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    ABSTRACT: Despite recent advances in its management, the outcome from cardiac arrest is often poor despite appropriate cardiopulmonary resuscitation (CPR). The coronary perfusion pressure (CPP) achieved during CPR is associated with successful return of spontaneous circulation (ROSC). Continuous balloon occlusion of the descending aorta is an experimental method that can occlude the 'unnecessary' part of the circulation, thus diverting generated pressure and blood flow to the heart and brain. We present a case report with a patient unresponsive to standard CPR in which constant intraaortic balloon occlusion achieved ROSC and successful survival.
    Resuscitation 01/2009; 80(2):281-3. · 3.60 Impact Factor
  • Article: Plasma ghrelin levels are associated with coronary microvascular and endothelial dysfunction in peritoneal dialysis patients.
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    ABSTRACT: Cardiovascular (CV) disease is the main cause of death in peritoneal dialysis (PD) patients, and endothelial dysfunction (ED) is an early sign of vascular pathology. Ghrelin, a gastric peptide with CV actions, has been shown to inhibit proatherogenic changes in experimental models. However, another peptide hormone, leptin, may mediate deleterious effects on the CV system. The aim of this study is to evaluate the relationship between plasma ghrelin and leptin levels, and their association with coronary microvascular and endothelial functions in PD patients. Twenty-four (14 females and 10 males; mean age 44 +/- 12 yr) nondiabetic PD patients, between 18 and 70 years of age, were enrolled. In addition to demographic, clinical, and laboratory parameters, plasma concentrations of ghrelin and leptin were evaluated. Endothelial functions of the coronary arteries were determined by coronary flow reserve (CFR) measurement using transthoracic Doppler echocardiography (TTDE). A CFR value of < 2 was used as an evidence for ED. When the study group was divided according to CFR measurements as CFR < 2 and >or= 2, there were no significant differences considering age, gender, etiology of renal disease, body mass index (BMI), duration of dialysis, PD modality, PD solution type, history of peritonitis, mean arterial pressure, ejection fraction, and biochemical parameters between the two subgroups. Plasma ghrelin levels (129.4 +/- 82.1 pg/mL) in patients with CFR >or= 2 were significantly higher than those in patients with CFR< 2 (63.3 +/- 35.8 pg/mL) (p = 0.03). However, no significant differences in plasma leptin levels were found between these groups [31.39 +/- 37.81 ng/mL vs. 63.95 +/- 72.83 ng/mL (p = 0.28)]. No correlation existed between plasma ghrelin levels and age, BMI, duration of dialysis, mean arterial pressure, ejection fraction, plasma leptin levels, and biochemical parameters. Decreased plasma ghrelin levels may contribute to the development of atherosclerosis in PD patients by causing ED.
    Renal Failure 01/2009; 31(9):807-13. · 0.82 Impact Factor
  • Article: Atrial and ventricular arryhthmogenic potential in Turner Syndrome.
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    ABSTRACT: P-wave dispersion (Pd), corrected P-wave dispersion (Pdc), QT-wave dispersion (QTd), and corrected QT-wave dispersion (QTdc) parameters were not assessed in Turner Syndrome (TS) before. The aim of this study is to investigate the cardiac arrhythmogenic potential in patients with TS. Thirty-one patients with TS and 30 healthy women were enrolled in the study. For this purpose 12-lead electrocardiogram (ECG) and 24-hour ambulatory ECG recordings were performed. Pd, Pdc, QTd, and QTdc were significantly higher in patients with TS. On 24-hour ambulatory ECG recording, the mean heart rate (HR) was higher, while the mean of all RR intervals between normal beats (MeanNN), the standard deviation of all the RR intervals (SDNN), the square root of the mean of the squared differences of two consecutive RR intervals (rMSSD), and the percentage of the beats with consecutive RR interval difference more than 50 milliseconds (pNN50) were lower in TS. There were significant increases in Pd, Pdc, QTd, and QTdc in patients with TS and they may be features of the disease. The frequency of supraventricular arrhythmias was increased. There also was a significant deterioration of sympathetic and parasympathetic components of autonomic function as assessed by heart rate variability (HRV) in Turner patients.
    Pacing and Clinical Electrophysiology 10/2008; 31(9):1140-5. · 1.35 Impact Factor