Muhammet Bilgi

Relationship of serum uric acid to measures of endothelial function and atherosclerosis in healthy adults

Although uric acid (UA) is considered as an antioxidant, the relationship between serum UA levels and cardiovascular diseases is not clear yet. Higher brachial artery resting diameter (BD), impaired brachial artery flow‐mediated dilatation (FMD), increased carotid intima‐media thickness (IMT), decreased aortic distensibility (AoD), and increased aortic stiffness index (AoSI) and elastic modulus (AoEM) are predictors for development and/or progression of atherosclerosis. In this study, BD, FMD, carotid IMT, AoD, AoSI and AoEM were studied in healthy subjects with UA concentrations in physiological range.

Statin therapy helps to control blood pressure levels in hypertensive dyslipidemic patients.

Aim. Aside from lowering lipid levels; statins improve endothelial function, decrease platelet aggregation, reduce procoagulant blood factors, and decrease vascular tone. This study was conducted to investigate the possible effect of atorvastatin on blood pressure (BP) in a group of hypertensive and dyslipidemic patients. Methods. Thirty-six hypertensive and dyslipidemic patients with inadequately controlled lipid levels by diet were treated with atorvastatin 20 mg/day for 8 weeks and compared with 24 patient matched controls treated with diet alone. The type and dosage of antihypertensive medications were not altered during statin therapy. Blood lipid profile including total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL) and triglyceride (TG) levels were noted at inclusion and after 8 weeks. Ambulatory BP monitoring (ABPM) was carried out at study entry and at the end of week eight. Results. A total of 49 patients (32 patients in the atorvastatin group and 17 patients in the control group) completed the 3-month follow-up period of observation. The ABPM studies indicated significant reductions in total average systolic BP, total average diastolic BP, total average mean BP, day average systolic BP, day average diastolic BP, night average systolic BP, night average diastolic BP, and night average mean BP levels in the atorvastatin group, whereas these reductions were not observed in the control group. Conclusion. Our results indicate that atorvastatin therapy significantly improves BP control in hyperlipidemic hypertensive patients. However, the effects of other statins on BP, as well as, the different dosages need to be further investigated.

Relation of Serum Parathyroid Hormone Level to Severity of Heart Failure

Increased parathyroid hormone (PTH) level is associated with all-cause mortality in patients with heart failure (HF). However its role for identifying advanced HF has not been previously studied. We aimed to investigate whether the assessment of serum PTH could enable clinicians to identify patients with advanced HF. One hundred fifty consecutive patients who visited our outpatient clinic with systolic HF were enrolled in the present study. Serum levels of PTH and brain natriuretic peptide (BNP) were measured across all New York Heart Association functional classes. Mean levels of PTH were 43 ± 19, 84 ± 56, 121 ± 47, and 161 ± 60 pg/ml in New York Heart Association functional classes I, II, III, and IV, respectively (p <0.001). In univariate analysis, body mass index, disease duration, PTH, BNP and hemoglobin levels, creatinine clearance, heart rate, systolic blood pressure, left ventricular ejection fraction, left ventricular diastolic diameter, left atrial size, presence of atrial fibrillation, and diuretic usage were found to be predictors of advanced HF. In multivariate logistic regression analysis, PTH level (hazard ratio 1.032, 95% confidence interval 1.003 to 1.062, p = 0.003) and body mass index (hazard ratio 0.542, 95% confidence interval 0.273 to 1.075, p = 0.079) were associated with advanced HF. Furthermore, serum PTH levels were correlated with BNP level and left ventricular ejection fraction (p <0.001 for the 2 comparisons). In receiver operator characteristics curve analysis, the optimal cut-off value of PTH to predict advanced HF was >96.4 pg/ml, with 93.3% sensitivity and 64.2% specificity. In conclusion, measurement of serum PTH could provide complementary information and a simple biomarker strategy to categorize patients with advanced HF based on increased PTH levels, allowing rapid risk stratification in these patients.

Efficacy of allopurinol pretreatment for prevention of contrast-induced nephropathy: a randomized controlled trial

BACKGROUND Contrast-induced nephropathy (CIN) remains a common complication of radiographic procedures. Radiocontrast agents can cause a reduction in renal function that may be due to reactive oxygen species. Conflicting evidence suggests that administration of antioxidants prevents CIN. METHODS We assessed the efficacy of allopurinol in preventing CIN. We prospectively randomized 159 patients with a serum creatinine concentration >1.1mg/dL undergoing cardiac catheterization/interventions to receive allopurinol (300 mg, p.o.) 24h before administration of radiocontrast agent and hydration (1mg/kg/hN/saline for 12h pre- and post-contrast, n=79), or hydration alone (1mg/kg/hN/saline for 12h pre- and post-contrast, n=80). RESULTS CIN occurred in 6 of 80 patients (7.5%) in the control group and no subjects in the allopurinol group (p=0.013). In the allopurinol group, median serum creatinine concentration decreased significantly from 1.43 mg/dL [1.1-4.15 mg/dL] to 1.35 mg/dL [0.7-4.15 mg/dl] at 48 h and to 1.27 mg/dL [0.66-4.37 mg/dL] at 4 days after radiocontrast administration (p<0.0001 and p<0.0001 compared with baseline, respectively). In the control group, median serum creatinine concentration decreased non-significantly from 1.48 mg/dL [1.1-2.96 mg/dL] to 1.43 mg/dL [0.73-3.02 mg/dL] and to 1.45 mg/dL [0.86-3.71 mg/dL] (p=0.045 and p=0.57, respectively) 48 h and 4 days after radiocontrast administration. CONCLUSIONS Prophylactic oral administration of allopurinol, along with hydration, may protect against CIN in high-risk patients undergoing coronary procedures.

Coronary flow reserve and coronary microvascular functions are strongly related to serum uric acid concentrations in healthy adults.

BackgroundUric acid is a well known antioxidant; however, the relationship between serum uric acid levels and oxidative stress-caused disorders including cardiovascular diseases is not clear yet. Transthoracic Doppler echocardiographic measurement of coronary flow reserve is a useful tool to investigate coronary flow reserve and coronary microvascular functions. In this study, we investigated the possible association between serum uric acid concentrations and coronary flow reserve in healthy adults. MethodsOne hundred healthy volunteers with normal uric acid levels, between 18 and 55 years of age, were included in this study. The study group was divided into two with regard to the serum uric acid levels. Coronary diastolic peak flow velocities were measured at baseline and after dipyridamole infusion (0.56 mg/kg over 4 min) using echocardiography. ResultsCoronary flow reserve and hyperemic mean peak flow velocity were significantly greater in participants with lower serum uric acid concentrations (≤234 μmol/l for women, ≤302 μmol/l for men) than in those with higher serum uric acid concentrations (>234 μmol/l for women, >302 μmol/l for men) (2.91±0.5 vs. 2.47±0.5, P<0.001; 66.8±11.4 vs. 61.1±16.5, P=0.04). The baseline mean peak flow velocity was significantly greater in participants with higher serum uric acid concentrations than in those with lower serum uric acid concentrations (24.7±4.1 vs. 23.1±2.4, P=0.02). ConclusionLower serum uric acid concentrations might be regarded as indicative of coronary microvascular and conductance vessel functionality.

Interpretation of Electrocardiogram Images Sent Through the Mobile Phone Multimedia Messaging Service

OBJECTIVE In this study, the diagnostic accuracy of interpretations of electrocardiogram (ECG) images taken by a mobile phone and sent as multimedia message was investigated. MATERIALS AND METHODS The ECGs of 305 patients who were admitted to the emergency department with cardiac complaints were photographed with the camera of a Nokia (Espoo, Finland) N93 mobile phone. The images were sent via a multimedia messaging system to an identical mobile phone carried by a cardiologist and were interpreted on the screen of that mobile phone. Another cardiologist and an emergency physician interpreted ECG paper printouts separately. The findings of the core laboratory were used as the gold standard. The interpretation errors were scaled from 1 to 4 with respect to the significance of findings. RESULTS The total ratio of Grade 4 errors, which consisted of significant errors, did not show any significant difference (p=0.76) between the interpretations by the emergency medicine specialist and the cardiologist who interpreted the ECGs on the mobile phone; the cardiologist who interpreted the ECG paper printouts made significantly fewer mistakes than the other two specialists (p=0.025 and p=0.023, respectively). The separate assessment of the findings showed that in the diagnostic process of ST-segment elevation, depression, and supraventricular tachycardia, the consistency of the interpretations (κ=0.81, κ=0.81, and κ=1.0, respectively) made on the mobile phone screen was slightly better than that of the emergency medicine specialist (κ=0.73, κ=0.77, and κ=0.80, respectively) and was similar to that of the cardiologist (κ=0.91, κ=0.91, and κ=1.0, respectively) who interpreted ECG paper printouts. CONCLUSIONS Our findings suggest that sending the ECG images via a multimedia message service may be a practical and inexpensive telecardiology procedure.

Coronary flow reserve in dipper and non-dipper hypertensive patients

Background. Failure to decrease blood pressure (BP) normally during night‐time, which is called non‐dipping, in hypertensive individuals is associated with higher cardiovascular morbidity and mortality. In addition, non‐dipping BP leads to structural changes in the left ventricle; however, the effect of non‐dipping BP on coronary flow reserve (CFR) has not been studied yet. Methods. In this study, we measured CFR of 22 subjects with non‐dipper hypertension, and 15 subjects with dipper hypertension using transthoracic second‐harmonic Doppler echocardiography (Acuson Sequoia C256®). None of the subjects had any systemic disease or coronary risk factor except hypertension. Results. Age, gender, body mass index, lipids and echocardiographic findings including left ventricular mass index were similar between the groups. Office BP recordings were similar between non‐dipper and dipper groups (147.9±6.1/93.9±4.3 vs 144.0±8.0/93.0±3.7). Daytime and 24‐h ambulatory BP measurements were similar within the groups, but night‐time BPs were significantly greater in non‐dipper group than those were in dipper group. Left ventricular diastolic and systolic functions, and both baseline and hyperemic peak diastolic coronary velocity as well as CFR, were similar between the non‐dipper and dipper groups (CFR: 2.47±0.59 vs 2.39±0.47). Conclusion. CFR were similar in patients with non‐dipper and dipper hypertension in the absence of excessive left ventricular hypertrophy and other cardiovascular risk factors.

Teleconsultation of coronary angiograms using smartphones and an audio/video conferencing application

OBJECTIVE To examine the feasibility and accuracy of teleconsultation of coronary angiograms using iPhone 4 and FaceTime. METHODS The study was conducted in two stages. Coronary angiograms of 100 patients with single-vessel disease were retrospectively selected by a core laboratory unit and then re-evaluated by a consultant cardiologist on both an iPhone 4 screen via the FaceTime application and on the workstation monitor of the angiography laboratory. The interpretations of the consultant cardiologist on localization and severity of angiographic lesions were recorded and compared with those of the core laboratory. Using the same teleconsultation system, the consultant cardiologist outside the hospital was presented live angiographic images of 10 patients undergoing primary percutaneous coronary intervention (PCI) for acute myocardial infarction. RESULTS Interpretations of the consultant cardiologist on the localization and severity of 100 lesions on both the smartphone screen and workstation monitor showed high levels of agreement with the results of the core laboratory (for all, κ > 0.80). Of 10 patients whose PCI was performed under live video teleconsultation, eight patients underwent successful PCI while two patients had normal coronary arteries. There was an excellent agreement between the consultant cardiologist and the operator regarding lesion localization. CONCLUSIONS Smartphones allow highly accurate interpretations on angiographic lesions and thus may serve as a supplementary teleconsultation tool in both elective and emergency situations.

Comparison of fibrinolytic versus surgical therapy in the treatment of obstructive prosthetic valve thrombosis: a single-center experience.

OBJECTIVE Prosthetic heart valve thrombosis (PVT) is a rare but severe cardiac condition. There are only a few data regarding comparison of the fibrinolytic and surgical approaches for the treatment of PVT. In this study, we compared the results of fibrinolytic therapy versus surgery in patients who presented to our institution with a diagnosis of obstructive-type PVT. METHODS From January 2001 to August 2008 in our institution, 33 patients who met clinical and echocardiographic criteria for obstructive-type PVT were included in the study. Fifteen of these patients underwent fibrinolytic treatment with streptokinase, which consisted of an initial bolus of 250,000 U followed by 100,000 U/h. Eighteen patients were treated with surgery. RESULTS The 2 groups had similar baseline characteristics, including New York Heart Association functional status, types and positions of prosthetic valves, international normalized ratio values, and presentation symptoms. Full hemodynamic success was achieved in 12 patients who underwent fibrinolytic therapy and in 15 patients in the surgery group. The mean (±SD) streptokinase infusion time was 17.8 ± 11.1 hours. Two major hemorrhages and 2 cases of systemic embolism were observed in the fibrinolytic group. The 2 groups did not differ with respect to mortality rate (P = .79). The duration of hospitalization was longer in the fibrinolytic group than in the surgery group (10.7 ± 6.6 days versus 6.9 ± 6.7 days, P = .045). CONCLUSIONS Although fibrinolytic therapy is generally recommended for the treatment of PVT for specific patient groups, our results suggest that it may be as efficacious and safe as surgery, depending on patient selection.

Low serum bilirubin concentrations are associated with impaired aortic elastic properties, but not impaired left ventricular diastolic function: Hypobilirubinemia impairs aortic elasticity

Elevated serum bilirubin concentrations protect from atherosclerotic diseases; however, it is not clear whether higher serum bilirubin concentrations in physiological ranges do the same. To investigate the association of high and low serum bilirubin concentrations with left ventricular diastolic function and aortic elastic properties. We evaluated left ventricular diastolic function and aortic elastic properties of 42 healthy subjects with hypobilirubinemia (total bilirubin 0.40 ± 0.08 mg/dl; mean age 37.0 ± 3.9) and 40 healthy subjects with hyperbilirubinemia (total bilirubin 1.56 ± 0.49 mg/dl; mean age 36.2 ± 6.0) using transthoracic second harmonic Doppler echocardiography. Age, gender, body mass index and coronary risk factors were similar between the groups, except high‐sensitivity C‐reactive protein (hsCRP). Left ventricular diastolic parameters were similar between the two groups. Aortic distensibility (AoD) was found to be significantly lower (11.1 ± 3.9 vs. 13.2 ± 4.9, p = 0.03) and aortic stiffness index (AoSI) (1.99 ± 0.30 vs. 1.85 ± 0.26, p = 0.02) and elastic modulus (AoEM) (2.06 ± 0.83 vs. 1.73 ± 0.68, p = 0.03; the low and high bilirubin groups, respectively) higher in the low bilirubin group. Serum total bilirubin concentration correlated with hsCRP levels, AoD, AoSI and AoEM. In conclusion, left ventricular systolic and diastolic functions were similar between hypo‐ and hyperbilirubinemic subjects, but aortic elastic properties were impaired in subjects with lower serum bilirubin concentrations.