Selahattin Akyol

The association of serum prolidase activity with the presence and severity of coronary artery disease.

ObjectivesProlidase is a cytosolic exopeptidase that cleaves iminodipeptides with carboxy-terminal proline or hydroxyproline and plays major role in collagen turnover. Collagen is the essential content in atherosclerotic plaque playing a key role in the stability/instability of and progression of coronary artery disease (CAD). Consequently, in this study we sought to determine serum prolidase activity and markers of oxidative stress such as lipid hydroperoxide and total free sulfhydryl in CAD. Design and methodsWe have evaluated 199 patients with CAD and 122 control cases with clinical, electrocardiographic, and laboratory investigation. We have measured serum prolidase activity and serum total free sulfhydryl levels spectrophotometrically. Serum lipid hydroperoxide levels were determined with ferrous ion oxidation-xylenol orange method. We assessed the association of serum prolidase activity with the presence and severity of CAD and clinical characteristics, and laboratory parameters. ResultsSerum prolidase activity (52.5±5.6 vs. 46.7±5.1 U/l, respectively, P<0.001) and serum lipid hydroperoxide levels were significantly increased in patients with CAD compared with control cases whereas, serum total free sulfhydryl levels were significantly decreased in patients with CAD compared with control cases. Serum prolidase activity and total free sulfhydryl levels were independent predictors of the presence of CAD [(χ2=75.532, ß=0.212, P=0.003) and (χ2=25.969, ß=−30.486, P=0.019), respectively] and Gensini score [(&bgr;=0.276, P<0.001) and (&bgr;=−0.274, P<0.001), respectively]. Independent predictors of serum prolidase activity were serum high-density lipoprotein cholesterol (&bgr;=−0.138, P=0.023) and urea levels (&bgr;=0.146, P=0.036), and Gensini score (&bgr;=0.317, P<0.001). ConclusionFindings of this study have shown that serum prolidase activity is significantly associated with the presence and severity of CAD, and elevated serum prolidase activity might be an independent predictor of coronary atherosclerosis.

Paraoxonase and arylesterase activities in untreated dipper and non-dipper hypertensive patients

OBJECTIVES Paraoxonase, a high density lipoprotein (HDL) associated enzyme, was shown to be reduced in patients with cardiovascular diseases. We aimed to examine serum paraoxonase and arylesterase activities, and oxidative stress markers such as lipid hydroperoxide (LOOH) and total antioxidant status (TAS) in dipper and non-dipper hypertensive patients. DESIGN AND METHODS Forty-six non-dipper hypertensives (NDH group), 40 dipper hypertensives (DH group) and 28 healthy control subjects were included in the study. Clinical and echocardiographic assessment and ambulatory blood pressure monitoring were performed in all subjects. Serum paraoxonase and arylesterase activities were measured spectrophotometrically. LOOH levels were measured by ferrous oxidation with xylenol orange assay. TAS was determined by using an automated measurement method. RESULTS Paraoxonase and arylesterase activities and TAS levels were significantly lower in patients with NDH compared to both DH and control groups (p<0.001, for both). Also, LOOH levels were found at high level in patients with NDH compared to control and DH groups. In NDH group, both paraoxonase and arylesterase activities were independently correlated with LDL cholesterol, TAS and LOOH levels. In DH group, both paraoxonase and arylesterase activities were independently correlated with HDL cholesterol and LOOH levels. CONCLUSIONS Reduced paraoxonase and arylesterase activities in NDH might indicate increased oxidative stress, which plays an important role in the development of cardiovascular diseases. Low serum activities of paraoxonase and arylesterase might be considered as prospective prognostic markers of the development of cardiovascular diseases in dipper and non-dipper hypertensive patients.

Paraoxonase-1 activity and oxidative stress in patients with anterior ST elevation myocardial infarction undergoing primary percutaneous coronary intervention with and without no-reflow.

BACKGROUND Reperfusion and ischemic injuries are pathogenetic mechanisms of no-reflow. Oxidative stress plays a critical role during ischemia as well as during the reperfusion phase following ST elevation myocardial infarction (STEMI). We sought to investigate the relationship between no-reflow with paraoxonase-1 (PON-1) activity and oxidative stress markers (total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), lipid hydro-peroxide (LOOH)) in patients with anterior STEMI undergoing primary percutaneous coronary intervention (PCI). METHODS In this study, 319 consecutive anterior STEMI patients undergoing primary PCI were prospectively included (mean age 56.5 ± 12.5 years). The patients were divided into two groups as normal flow (n = 231) and no-reflow (n = 88) groups. Serum PON-1 activity was measured spectrophotometrically. TAC and TOS levels were determined by using an automated measurement method. LOOH levels were measured by ferrous oxidation with xylenol orange assay. RESULTS PON-1 activity and TAC levels were significantly lower and TOS, OSI and LOOH levels were significantly higher in patients with no-reflow compared to normal flow group (p < 0.05, for all). On multivariate logistic regression analysis, PON-1 activity (β = 0.976, 95% CI = 0.962-0.990, p = 0.001) and OSI (β = 1.094, 95% CI = 1.042-1.148, p < 0.001) as well as diabetes, infarction time, thrombus score and initial SYNTAX score were independently associated with no-reflow. CONCLUSION In patients with no-reflow compared with normal flow, oxidants are increased, while serum PON-1 activity and antioxidants are decreased. This result shows that increased oxidative stress has a role in the pathogenesis of no-reflow.

Serum 25-Hydroxyvitamin D Level Is Associated With Arterial Stiffness, Left Ventricle Hypertrophy, and Inflammation in Newly Diagnosed Hypertension

Objectives Vitamin D may modulate vascular inflammation, vascular smooth muscle cell proliferation, the renin-angiotensin system, and cardiomyocyte proliferation, myocardial fibrosis, and proliferation. These mechanisms may play a role on arterial stiffness and left ventricle hypertrophy (LVH) in hypertensive patients. We aimed to evaluate the association between serum vitamin D with arterial stiffness and LVH in patients with hypertension. Methods We studied 133 patients with newly diagnosed hypertension [mean (SD) age, 62.9 (10.6) years]. Pulse wave velocity (PWV), which reflects arterial stiffness, was calculated using the single-point method via the Mobil-O-Graph ARCsolver algorithm. Left ventricular mass index (LVMI) was determined according to Deverux formula. The patients were divided into the following 2 groups according to serum vitamin D level: vitamin Dlow group with less than 20 ng/mL and vitamin Dhigh group with greater than or equal to 20 ng/mL. Results The highest PWV, high-sensitivity C reactive protein, and LVMI values were observed in vitamin Dlow group compared with vitamin Dhigh group. Multiple linear regression analysis showed that vitamin D level was independently associated with LVMI (β = −0.235, P = 0.002) and PWV (β = −0.432, P < 0.001). Adjustment for age, sex, parathyroid hormone level, body surface area, and mean blood pressure did not modify these associations. Vitamin D level was also independently associated with high-sensitivity C reactive protein (β = −0.143, P = 0.047). However, adjustment for parathyroid hormone level or body surface area and mean blood pressure attenuate this association. Conclusions Serum 25-hyroxyvitamin D is independently related with arterial stiffness, LVH, and inflammation. Vitamin D may play a role on pathogenesis of arterial stiffness and LVH in patient with newly diagnosed hypertension.

Serum 25‐Hydroxyvitamin D Level and Extent and Complexity of Coronary Artery Disease

There are limited number of studies about relationship between serum vitamin D level and presence and severity of coronary artery disease (CAD). We assessed the relationship between the extent and complexity of CAD assessed by SYNTAX score and 25‐hydroxyvitamin D level in patients with stable CAD.

Aortic stiffness increases in proportion to the severity of apnoea–hypopnea index in patients with obstructive sleep apnoea syndrome

Obstructive sleep apnoea syndrome (OSA) and aortic stiffness are associated with an increased risk of cardiovascular morbidity and mortality. Although aortic stiffness increased in patients with OSA, the relationship between severity of OSA indicated with apnoea–hypopnea index (AHI) and aortic stiffness was not investigated in previous studies. The aim of this study is to investigate the relationship between the severity of OSA and aortic stiffness.

Mean platelet volume is associated with disease severity in patients with obstructive sleep apnea syndrome.

OBJECTIVE: Obstructive sleep apnea syndrome is associated with cardiovascular diseases and thromboembolic events. The mean platelet volume (MPV) is a predictor of cardiovascular thromboembolic events. The aim of the present study is to investigate the association between the MPV and disease severity in patients with obstructive sleep apnea syndrome. METHODS: We prospectively included 194 obstructive sleep apnea syndrome patients without cardiovascular disease (mean age 56.5±12.5 years) who were undergoing sleep tests. An overnight full laboratory polisomnography examination was conducted on each patient. The patients were divided into 3 groups according to the apnea-hypopnea index (AHI): (1) AHIlow group: 5≤AHI<15, (2) AHImid group: 1530. RESULTS: The highest MPV values were found in the AHIhigh group compared with other groups (p<0.05 for all). Multiple linear regression analysis indicated that the MPV was associated with the AHI (β=0.500, p<0.001) and the high sensitivity C-reactive protein (hs-CRP) level (β=0.194, p=0.010). CONCLUSION: The MPV is independently associated with both disease severity and inflammation in patients with obstructive sleep apnea syndrome.

Predictors of successful percutaneous coronary intervention in chronic total coronary occlusions

Introduction Percutaneous coronary intervention (PCI) of chronic total coronary occlusions (CTOs) is one of the most challenging procedures of interventional cardiology and is associated with increased risk of significant complications. However, debate continues in regard to which factors adversely influence the success rate of PCI and whether the benefits of revascularization of CTO outweigh the risks and challenges. Aim To analyze the relationship between lesion characteristics and overall success rates as well as in-hospital outcomes after PCI for CTO. Material and methods We retrospectively examined the procedural outcomes of 173 consecutive native coronary artery CTO PCIs performed from February 2012 to March 2013 (78% men; mean age: 60.3 ±12.1 years). Results The CTO target vessel was the right coronary artery (53.8%), circumflex (10.4%) and left anterior descending artery (35.8%), respectively. The retrograde approach was used in 13.9% of all procedures. Successful revascularization was achieved in 83.2% of patients. Major complications occurred in 13.3% of patients. In multivariate analysis, bridge collaterals, severe calcification and tortuosity as well as tandem occlusions were independent predictors of procedural failure, whereas existence of micro-channels was the only predictor of procedural success. Conclusions Revascularization of coronary CTOs may be performed with high success and low major complication rates. Bridge collaterals, severe calcification and tortuosity, tandem/multiple occlusions and micro-channels were independent predictors of successful CTO revascularization.

Biventricular Myocardial Performance Is Impaired in Proportion to Severity of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is an independent risk factor for cardiovascular morbidity and death. Little information is available regarding the relationship between the severity of OSA and myocardial performance in OSA patients who have normal ejection fractions. We prospectively investigated this relationship, using the tissue-Doppler myocardial performance index (TD-MPI). We conducted overnight, full-laboratory polysomnographic examinations of 116 patients, and calculated the left and right ventricular TD-MPIs. Patients were classified into 3 groups in accordance with their apnea-hypopnea index (AHI) levels: AHImild (≥5 to <15), AHImoderate (≥15 to <30), and AHIsevere (≥30). Left and right ventricular TD-MPI values were higher in the AHIsevere group than in the AHImild and AHImoderate groups (all P <0.05). In addition, right ventricular TD-MPI values in the AHImoderate group were higher than those in the AHImild group (P <0.05). Right ventricular TD-MPI was significantly associated with AHI (β=0.468, P <0.001), left ventricular TD-MPI, and right ventricular early-to-late filling velocities (E/A ratio) in multiple linear regression analysis. On the other hand, left ventricular TD-MPI was significantly associated with right ventricular TD-MPI and left ventricular E/A ratio (both P <0.05). Our results show that OSA severity, determined by means of AHI, is independently associated with impaired right and left ventricular function as indicated by TD-MPI in patients who have OSA and normal ejection fractions.

Gamma Glutamyl Transferase Activity is Associated With Both Paraoxonase Activity and Aortic Stiffness in Hypertensive Patients

We aimed to investigate relationship between gamma glutamyl transferase (GGT) activity with paraoxonase 1 (PON1) activity and aortic stiffness (AS) parameters such as pulse wave velocity (PWV) and augmentation index (AIx).