Serkan Bulur

Lipoprotein(a) is associated with coronary heart disease independent of metabolic syndrome

AimTo assess (i) the association between lipoprotein(a) [Lp(a)] with the likelihood of coronary heart disease and metabolic syndrome (MS) and (ii) its covariates in Turkish adults. MethodsCross-sectional evaluation of 1309 adults, who had serum Lp(a) determinations by Behring nephelometry, and followed for a mean 1.0 year. MS was defined by ATPIII criteria modified for male abdominal obesity. ResultsMean age of the sample was 56.8±11.3 years. After adjustment for sex, age, and smoking status, log-transformed Lp(a) levels were associated significantly with coronary heart disease likelihood in both sexes combined [odds ratio: 1.53 (95% confidence interval: 1.06; 2.20)]. This association persisted after additional adjustment for MS [odds ratio: 1.57 (95% confidence interval: 1.09; 2.26)]. The Lp(a) mid-tertile (5–17 mg/dl), accompanied by significantly lower serum triglycerides than the two remaining tertiles, was inversely associated significantly with MS in either sex; in women, this association was independent of waist circumference. In a linear regression comprising seven variables, excepting total cholesterol, only &ggr;-glutamyltransferase in women (P=0.002) and waist circumference (P=0.057) in men were inverse covariates of modest magnitude of Lp(a). ConclusionCoronary heart disease likelihood, significantly associated with Lp(a) concentrations, is independent of MS and insulin resistance. Suggestive evidence was provided that intermediary Lp(a) concentrations, when accompanied by the presence of MS, could accelerate progression of vascular disease, especially in women.

Increased morning blood pressure surge and coronary microvascular dysfunction in patient with early stage hypertension

Morning blood pressure surge (MBPS) is defined as an excessive increase in blood pressure (BP) in the morning from the lowest systolic BP during sleep, and it has been reported as a risk factor for cardiovascular events in current clinical studies. In this study, we evaluated the association between the rate of BP variation derived from ambulatory BP monitoring data analysis and coronary microvascular function in patients with early stage hypertension. One hundred seventy patients with prehypertension and Stage 1 hypertension who fulfilled the inclusion and exclusion criteria were included in the study. We divided our study population into two subgroups according to the median value of coronary flow reserve (CFR). Patients with CFR values <2.5 were defined as the impaired CFR group, and patients with CFR values ≥2.5 were defined as the preserved CFR group, and we compared the MBPS measurements of these two subgroups. CFR was measured using transthoracic Doppler echocardiography (TTDE). Ambulatory 24-hour systolic and diastolic BP, uric acid, systolic MBPS amplitude, diastolic MBPS amplitude, high-sensitivity C-reactive protein, and mitral flow E/A ratio were statistically significant. These predictors were included in age- and gender-adjusted multivariate analysis; ambulatory 24-hour systolic BP (ß = 0.077, P < .001; odds ratio [OR] = 1.080; 95% confidence interval [CI] [1.037-1.124]) and systolic MBPS amplitude (ß = 0.043, P = .022; OR = 1.044; 95% CI [1.006-1.084]) were determined to be independent predictors of impaired CFR (Hosmer-Lemeshow test, P = .165, Nagelkerkes R(2) = 0.320). We found that increased changes in MBPS values in patients with prehypertension and Stage 1 hypertension seemed to cause microvascular dysfunction in the absence of obstructive coronary artery disease.

Predicting heart transplantation outcomes through data analytics

Predicting the survival of heart transplant patients is an important, yet challenging problem since it plays a crucial role in understanding the matching procedure between a donor and a recipient. Data mining models can be used to effectively analyze and extract novel information from large/complex transplantation datasets. The objective of this study is to predict the 1-, 5-, and 9-year patients graft survival following a heart transplant surgery via the deployment of analytical models that are based on four powerful classification algorithms (i.e. decision trees, artificial neural networks, support vector machines, and logistic regression). Since the datasets used in this study has a much larger number of survival cases than deaths for 1- and 5-year survival analysis and vice versa for 9-year survival analysis, random under sampling (RUS) and synthetic minority over-sampling (SMOTE) are employed to overcome the data-imbalance problems. The results indicate that logistic regression combined with SMOTE achieves the best classification for the 1-, 5-, and 9-year outcome prediction, with area-under-the-curve (AUC) values of 0.624, 0.676, and 0.838, respectively. By applying sensitivity analysis to the data analytical models, the most important predictors and their associated contribution for the 1-, 5-, and 9-year graft survival of heart transplant patients are identified. By doing so, variables, whose importance changes over time, are differentiated. Not only this proposed hybrid approach gives superior results over the literature but also the models and identification of the variables present important retrospective findings, which can be the basis for a prospective medical study. A data-driven approach for predicting survival outcomes at multiple time-points is developed.The method successfully predicted short-, mid-, & long-term heart transplantation outcomes.The proposed method is unique in that it fills an important gap in the published literature.The approach is generic so it can be applied to other organ transplantation cases.

Association of omentin Val109Asp polymorphism with coronary artery disease.

OBJECTIVE Coronary artery disease (CAD) is the most important morbidity and mortality disease in the world. It is also one of the leading causes of death in Turkey. Omentin, a recently found adipocytokine, is reported to regulate insulin sensitivity. It has anti-inflammatory properties and is inversely associated with CAD. Omentin gene polymorphism in patients with CAD has not been studied yet. The aim of this study is to investigate the relationship between omentin Val109Asp polymorphism and CAD. METHODS This is an observational study on genetic association. 157 consecutive patients who had undergone coronary angiography were included in the study. Seventy-five of them had CAD and the rest serves the control group. Val109Asp polymorphism was analyzed and compared. Chi-square test was used in comparison of genotype frequencies, whereas ANOVA and chi-square tests were used in comparison of clinical characteristics according to the genotypes. RESULTS There was no significant difference between CAD patients and control subjects regarding omentin Val109Asp polymorphism. However, a 2.5 fold increase in Val/Val (homozygous mutant) genotype was detected in patients with CAD. The OR (80% Cl) for Val/Val genotype was 3.46 (1.14-10.49). CONCLUSION Although no significant difference was detected regarding omentin Val109Asp polymorphism, Val/Val genotype frequency was found to be more in patient group than control group. In conclusion, it may be speculated that Val/Val genotype increases the tendency for CAD, but this experiment should done with larger population to clarify this issue.

Serum folate is associated with coronary heart disease independently of homocysteine in Turkish men

BACKGROUND & AIMS Whether serum homocysteine levels are associated with coronary heart disease (CHD) and the metabolic syndrome (MS) needs investigation in different ethnic groups. These associations and the influence of serum folate and vitamin B(12) thereupon were addressed separately in genders. METHODS A random sample of Turkish adults was studied cross-sectionally. RESULTS Median age of 338 men and 342 women was 55 years. Geometric mean serum homocysteine concentrations were 12.7+/-1.5 micromol/l in men and 9.6+/-1.4 micromol/l in women (p<0.001). Linear regression analysis among 11 variables revealed male sex, reduced estimated glomerular filtration rate (eGFR) and vitamin B(12), (in men) reduced folate as significant independent covariates of higher homocysteine levels. Logistic regression analysis disclosed that (sex-specific) top versus bottom homocysteine tertile was borderline significantly and independently associated with CHD in men and both genders combined, after adjustment for gender, age, smoking status, systolic blood pressure, eGFR, folate and vit B(12). Folate revealed significant inverse association with CHD likelihood in men and combined genders (OR 0.73 for doubling [95%CI 0.56; 0.94]), independently of homocysteine levels and even of presence of type-2 diabetes. Serum vit B(12) concentrations were significantly associated with MS likelihood in women alone after adjustment for sex, age, smoking status, folate and antidiabetic medication. CONCLUSION High serum homocysteine and low folate levels are associated in Turkish men independently with CHD, which needs confirmation in a larger sample. In women, vitamin B(12) concentrations are significantly associated with MS likelihood.

Elastic Properties of the Ascending Aorta and Left Ventricular Function in Patients with Hypothyroidism: ELASTIC PROPERTIES OF ASCENDING AORTA AND LV FUNCTION

Background: We sought to clarify the possible role of elastic properties of the ascending aorta in the development of cardiac disease associated with hypothyroidism (HT). Methods: A total of 37 patients with HT (age: 39.3 ± 8.9 years) and 29 control subjects were studied. Ascending Aortic (Ao) diameter, Ao elastic indexes, strain (AoST), distensibility (AoD), stiffness index (AoSI), and pressure strain modulus were calculated from the echocardiographically derived Ao diameters. Myocardial performance index (MPI), E/A ratio, isovolumetric relaxation time (IVRT), deceleration time (DT) were measured by Doppler echocardiography to assess diastolic LV function. Patients were treated with levothyroxine and followed‐up for 6 months. Thyroid function tests and echocardiographic measurements were repeated at the end of the study. Results: AoD (cm2 dyn−1 10−3) and AoST (%) were significantly lower (3.8 vs. 6.1; P < 0.001, 7.4 vs. 12.6, P < 0.001; respectively), whereas AoSI was higher in HT patients (6.2 vs. 3.3; P < 0.001). After treatment, AoD and AoST were increased (5.7; P < 0.001 and 11.8; P < 0.001; respectively), whereas AoSI was decreased significantly (3.7; P < 0.001). Also, early/late mitral peak velocity ratio (Emax/Amax) was significantly lower in HT patients (1.19 vs 1.34; P < 0.01), whereas MPI was higher (0.52 vs. 0.42; P < 0.001). MPI showed a strong correlation with aortic root indexes [AoST (r =−0.61/P < 0.001); AoD, (r =−0.57/P < 0.002); AoSI, (r = 0.53/P < 0.005)] in the HT group. After 6 months of therapy, MPI significantly decreased P < 0.001) and E/A ratios were normalized (P < 0.001). Conclusions: Ao root functions have an important role on diastolic LV function. Levothyroxine replacement therapy can reverse all of these adverse effects of HT.

Incremental Value of Live/Real Time Three-Dimensional Transthoracic Echocardiography over Two-Dimensional Echocardiography in Hypertrophic Cardiomyopathy with Mid-Ventricular Obstruction and Apical Aneurysm

We describe a case of hypertrophic cardiomyopathy with mid‐left ventricular obstruction and apical aneurysm containing thrombi where live/real time three‐dimensional transthoracic echocardiography provided incremental value over two‐dimensional echocardiography in assessing the findings.

Incremental Value of Live/Real Time Three-Dimensional over Two-Dimensional Transesophageal Echocardiography in the Assessment of Atrial Septal Pouch.

An atrial septal pouch (ASP) results from partial fusion of the septum primum and the septum secundum, and depending on the site of fusion, the pouch can be left‐sided (LASP) or right‐sided (RASP). LASPs have been described in association with thrombi found in patients admitted with acute strokes, raising awareness of its potential cardioembolic role, especially in those with no other clearly identifiable embolic source. We retrospectively studied 39 patients in whom the presence of an ASP had been identified by three‐dimensional transesophageal echocardiography (3DTEE) and who had a two‐dimensional transesophageal echocardiogram (2DTEE) performed during the same clinical encounter. The incremental value provided by 3DTEE over 2DTEE included the detection of six ASPs not found by 2DTEE; the detection of two ASPs in the same subject (in four patients) not identified by 2DTEE; larger ASP measurements of length and height in over 80% of the cases; and measurement of the ASP width (elevational axis) for the calculation of the area of the ASP opening, because of its unique capability to view the pouch en face. In addition, the volume of ASP and of the echogenic masses contained in the ASP (four of 39 patients) could be calculated by 3DTEE, which is a superior parameter of size characterization when compared to individual dimensions. One of these patients who presented with ischemic stroke diagnosed by magnetic resonance imaging had a large (>2 cm) mass in a LASP, with echolucencies similar to those seen in thrombi and associated with clot lysis and resolution. This mass completely disappeared on anticoagulant therapy lending credence that it was most likely a thrombus. There was no history of stroke or any other type of embolic event in the other three patients with masses in ASP. In conclusion, this retrospective study highlights the incremental value of 3DTEE over 2DTEE in the comprehensive assessment and characterization of ASPs, which can aid in the clarification of their role in cryptogenic stroke patients.

Myocardial performance index in patients with dipper and nondipper hypertension.

BackgroundThe aim of this study was to evaluate the relationship between left ventricular (LV) myocardial performance index (MPI) and nondipper pattern in hypertensive patients. MethodsBetween June 2012 and November 2012, patients admitted to the Cardiology Department of Düzce University Faculty of Medicine and diagnosed previously with essential hypertension were included in the study. Patients were divided into two groups, nondippers and dippers, using ambulatory blood pressure measurement. All patients were evaluated by two-dimensional and Doppler echocardiography. LV MPI was calculated from tissue Doppler imaging parameters. ResultsThere was no significant difference between the two groups in the proportion of each class of antihypertensive medications. Dippers and nondippers had similar age, BMI, lipid profiles, and smoking status. The MPI value was significantly higher in nondippers than in dippers, and was correlated negatively with the rate of systolic and diastolic blood pressure fall at night (P<0.001). ConclusionOur study showed that MPI is disturbed in patients with nondipper hypertension. MPI may be used in the diagnosis and follow-up of global LV dysfunction in patients with a nondipper pattern, but further prospective studies are needed.

Efficacy of olmesartan therapy on fibrinolytic capacity in patients with hypertension

The efficacy of olmesartan on fibrinolytic capacity has not been studied yet. Therefore, the aim of the present study was to investigate the efficacy of olmesartan on hemostatic/fibrinolytic status by measuring plasma level of plasminogen activator inhibitor-1 (PAI-1) and soluble thrombomodulin levels in patients with hypertension. Forty-two consecutive, newly diagnosed (25 women and 17 men with a mean age of 48 ± 8 years) patients with untreated essential hypertension were included in the study. Olmesartan medoxomil (20 mg/day) was started and the patients were followed up for 6 months. Baseline biochemical variables, thrombomodulin, and PAI-1 levels were compared with the levels of these variables measured at the end of the 6-month follow-up period. After 6 months of treatment with olmesartan medoxomil, there was a significant reduction in systolic and diastolic blood pressure (from 159.5 ± 10.9 to 134.6 ± 12.7 mmHg and from 98.0 ± 6.3 to 83.9 ± 7.0 mmHg, respectively). Mean plasma PAI-1 and thrombomodulin levels were also significantly decreased (59.73 ± 41.91 vs. 48.60 ± 33.65 ng/ml, P = 0.001 and 8.09 ± 2.29 vs. 6.92 ± 1.42 μg/l, P < 0.001, respectively). Olmesartan medoxomil decreased plasma PAI-1 and thrombomodulin levels after 6 months of therapy, indicating a favorable effect on fibrinolytic capacity in patients with essential hypertension.