Mehmet Ozaydin

N-acetylcysteine for the prevention of postoperative atrial fibrillation: a prospective, randomized, placebo-controlled pilot study

AIMS Oxidative stress has recently been implicated in the pathophysiology of atrial fibrillation (AF). The aim of the present study was to evaluate the effects of antioxidant agent N-acetylcysteine (NAC) on postoperative AF. METHODS AND RESULTS The population of this prospective, randomized, double-blind, placebo-controlled study consisted of 115 patients undergoing coronary artery bypass and/or valve surgery. All the patients were treated with standard medical therapy and were randomized to NAC group (n = 58) or placebo (saline, n = 57). An AF episode >5 min during hospitalization was accepted as endpoint. During follow-up period, 15 patients (15/115, 13%) had AF. The rate of AF was lower in NAC group compared with placebo group (three patients in NAC group [5.2%] and 12 patients in placebo group [21.1%] had postoperative AF; odds ratio [OR] 0.20; 95% confidence interval [CI] 0.05 to 0.77; P = 0.019). In the multivariable logistic regression analysis, independent predictors of postoperative AF were left atrial diameter (OR, 1.18; 95% CI, 1.06-1.31; P = 0.002) and the use of NAC (OR, 0.20; 95% CI, 0.04-0.91; P = 0.038). CONCLUSION The result of this study indicates that NAC treatment decreases the incidence of postoperative AF.

Mobile phone-induced myocardial oxidative stress: protection by a novel antioxidant agent caffeic acid phenethyl ester.

Electromagnetic radiation (EMR) or radiofrequency fields of cellular mobile phones may affect biological systems by increasing free radicals, which appear mainly to enhance lipid peroxidation, and by changing the antioxidant defense systems of human tissues, thus leading to oxidative stress. Mobile phones are used in close proximity to the heart, therefore 900 MHz EMR emitting mobile phones may be absorbed by the heart. Caffeic acid phenethyl ester (CAPE), one of the major components of honeybee propolis, was recently found to be a potent free radical scavenger and antioxidant, and is used in folk medicine. The aim of this study was to examine 900 MHz mobile phone-induced oxidative stress that promotes production of reactive oxygen species (ROS) and the role of CAPE on myocardial tissue against possible oxidative damage in rats. Thirty rats were used in the study. Animals were randomly grouped as follows: sham-operated control group (N: 10) and experimental groups: (a) group II: 900 MHz EMR exposed group (N: 10); and (b) group III: 900 MHz EMR exposed+CAPE-treated group (N: 10). A 900 MHz EMR radiation was applied to groups II and III 30 min/day, for 10 days using an experimental exposure device. Malondialdehyde (MDA, an index of lipid peroxidation), and nitric oxide (NO, a marker of oxidative stress) were used as markers of oxidative stress-induced heart impairment. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities were studied to evaluate the changes of antioxidant status. In the EMR exposed group, while tissue MDA and NO levels increased, SOD, CAT and GSH-Px activities were reduced. CAPE treatment in group III reversed these effects. In this study, the increased levels of MDA and NO and the decreased levels of myocardial SOD, CAT and GSH-Px activities demonstrate the role of oxidative mechanisms in 900 MHz mobile phone-induced heart tissue damage, and CAPE, via its free radical scavenging and antioxidant properties, ameliorates oxidative heart injury. These results show that CAPE exhibits a protective effect on mobile phone-induced and free radical mediated oxidative heart impairment in rats.

Statin Use before By-Pass Surgery Decreases the Incidence and Shortens the Duration of Postoperative Atrial Fibrillation

Backround: The aim of the present observational study is to search the incidence of postoperative atrial fibrillation (AF) in patients with or without preoperative statin treatment. Methods andResults: The population consisted of 362 consecutive patients (267 on and 95 not on statin). Diabetes mellitus was more frequent in statin group (p = 0.03). Other demographic and procedural variables were similar in the both groups (All p > 0.05). Postoperative AF was less frequent and its duration was shorter in statin group compared to non-statin group (p = 0.03 and 0.0001, respectively). The Kaplan-Meier analysis showed the protective effect of statins against the risk of developing AF (p = 0.01). Conclusion: Statin treatment before the by-pass surgery decreases the incidence and shortens the duration of postoperative AF.

Mean platelet volume is increased in patients with severe obstructive sleep apnea

Abstract Increased platelet activation and aggregation which are closely related to cardiovascular complications have been reported in patients with obstructive sleep apnea (OSA). The aim of this study was to assess the mean platelet volume (MPV), an indicator of platelet activation in patients with OSA. The 95 subjects referred for evaluation of OSA underwent overnight polysomnography. Blood samples were taken for MPV determination. According to the apnea-hypopnea index (AHI), subjects were divided into three groups; group 1: control subjects without OSA (AHI < 5, n = 24), group 2: patients with mild to moderate OSA (AHI: 5–30, n = 42), and group 3: severe OSA (AHI > 30, n = 29). Body mass index (BMI) of patients with severe OSA was significantly higher than control subjects (31.5 ± 4.0 vs. 28.2 ± 5.0; p = 0.02). The MPV was significantly higher in patients with severe OSA than in the control group (8.9 ± 1.0 vs. 8.2 ± 0.7 fl; p = 0.01). Correlation analysis within 71 patients with OSA indicated that MPV was correlated with AHI (p < 0.001, r = 0.44) and DI (p = 0.001, r = 0.37). In multivariate regression analysis, when MPV was taken as independent with other study variables which are potential confounders such as age, gender and BMI, MPV was independently correlated with both AHI (β = 0.44, p < 0.001) and DI (β = 0.38, p < 0.001). We have shown that MPV was significantly higher in patients with severe OSA when compared with control subjects and MPV was correlated with AHI and DI.

Matrix metalloproteinases and inflammatory markers in coronary artery ectasia: their relationship to severity of coronary artery ectasia.

ObjectiveAlthough underlying mechanisms of coronary artery ectasia (CAE) are clearly unknown, destruction of extracellular matrix may be responsible for the ectasia formation. Thus, we investigated the role of matrix metalloproteinases (MMP), tissue inhibitor of matrix metalloproteinases (TIMP-1), and inflammatory markers [high-sensitive C-reactive protein, interleukins (ILs)] in CAE patients. MethodsThis study consisted of 28 consecutive CAE patients, 27 obstructive coronary artery disease (CAD) patients, and 22 controls with normal coronary arteries undergoing cardiac catheterization. Plasma levels of MMP-3, MMP-9, TIMP-1, and inflammatory markers were measured. ResultsPlasma level of MMP-3 was significantly higher in CAE patients compared with both CAD patients and controls (17.2±6.1, 11.2±3.2, and 9.2±3.4 ng/ml, respectively, both P=0.001) and so did MMP-9 level (27.4±5.9, 24.8±4.4, and 20.6±4.6 ng/ml, respectively, both P<0.05). IL-6 level was also higher in CAE patients than in controls (60.9±22.1 vs. 36.1±21.5 pg/ml, P=0.001) but were comparable in CAE and CAD patients. Plasma high-sensitive C-reactive protein, IL-1, and TIMP-1 levels were similar in three groups. MMP-3 levels correlated with diffuse (r=0.46, P=0.01) and multivessel ectasia (r=0.45, P=0.02). ConclusionOur results suggest that the increased level of MMP-3, MMP-9, and IL-6 may be responsible for ectasia formation in patients with CAE.

Mean platelet volume in patients with prehypertension and hypertension

Patients with hypertension have evidence of platelet activation. Mean platelet volume (MPV), an indicator of platelet activation has been shown to be elevated in patients with hypertension. Prehypertension is also associated with an increase in cardiovascular morbidity and mortality. The aim of this study was to assess the MPV in patients with prehypertension and hypertension. This study included newly diagnosed and untreated 87 prehypertensive patients, 30 hypertensive patients and 35 normotensive control subjects matched for age, gender, and body mass index. All patients and controls gave informed consent. The MPV values of patients with prehypertension and hypertension were significantly higher than those of the control group (8.4 +/- 0.8 and 8.8 +/- 0.7 versus 7.9 +/- 0.5 fl; p < 0.05 and p < 0.001 respectively). It was also higher in hypertensives than in prehypertensives (8.8 +/- 0.7 versus 8.4 +/- 0.8 fl; p < 0.05). However, we found that the presence of the hypertension (beta = 0.28, P = 0.003) was only significant predictors of higher MPV in a multivariable model that adjusted for other variables. We have shown that, MPV, an indicator of platelet activation was significantly higher in patients with prehypertension and hypertension when compared with control subjects. We have also showed that MPV was also higher in patients with hypertension than in patients with prehypertension. However, presence of the hypertension was only significant predictor of higher MPV.

Tumour marker levels in patients with chronic heart failure

Carbohydrate Antigen 125 (CA 125), a marker for ovarian cancer has been reported to increase in relation to the severity of heart failure.

Effect of Smoking Cessation on Mean Platelet Volume

The aim of this study was to assess the values of mean platelet volume (MPV) in regular smokers and the effect of smoking cessation on MPV. The study group consisted of 116 regular smokers (57 females and 59 males; mean age 46.3 ± 12.7 years) and the control group was composed of 90 healthy volunteers (49 females and 41 males; mean age 47.7 ± 8.3 years). Platelet indices were assessed in regular smokers and control participants. Platelet indices were measured at 3 months after smoking cessation in these 101 participants. The MPV values were significantly higher in smokers than those of controls (8.8 ± 0.9 vs 8.0±0.8 fL, respectively; P < .001). The MPV values decreased significantly at 3 months when compared with the baseline values (8.9 ± 1.0 vs 7.9 ± 0.7 fL, respectively; P < .001). We have found that serum MPV values were significantly higher in regular smokers than in controls. Serum MPV values decreased significantly at 3 months after smoking cessation.

Effects of normal blood pressure, prehypertension, and hypertension on autonomic nervous system function

BACKGROUND Autonomic nervous system plays an important role in blood pressure (BP) regulation, and large proportion of patients with hypertension have increased sympathetic and decreased parasympathetic activity. Heart rate recovery (HRR) is a simple non-invasive measurement for investigating autonomic nervous system influence on the cardiovascular system; however, this methodology has not been used to evaluate autonomic nervous system in subjects with prehypertension (PHT). Accordingly, the present study was designed to evaluate HRR in subjects with PHT. METHODS AND RESULTS We measured HRR of 91 subjects with PHT, 44 patients with hypertension, and 53 normotensive healthy volunteers. HRR was significantly lower in the HT and PHT groups as compared to the control group (24.4 ± 5.7, 26.0 ± 8.4, 30.0 ± 8.7; hypertension, PHT, and control groups, respectively), but it did not significantly differ between HT and PHT groups. HRR was significantly and inversely correlated with age, systolic and diastolic BP, fasting and postprandial glucose level, waist circumference, total cholesterol, LDL cholesterol and non-HDL cholesterol, whereas exercise duration and METs were positively correlated with HRR. In multivariable analysis, we found that systolic BP, postprandial glucose level and exercise duration were independent predictors of lower HRR. CONCLUSIONS HRR, a non-invasive measurement analyzing the dysfunction in autonomic nervous system, was reduced in subjects with PHT as compared to normotensives, and the subjects with PHT had HRR as lower as patients with HT did. Our findings are supportive for the hypothesis that autonomic dysregulation is present in an early stage of essential hypertension.

A comparison of P-wave duration and dispersion in patients with short-term and long-term atrial fibrillation

This study compared P-wave duration and dispersion (PD) in patients with short-term (<or=48 hours) and long-term (>48 hours) atrial fibrillation (AF) after cardioversion. We studied 96 consecutive patients with short-term (group A; n:51, age: 61 +/- 11 years) and long-term AF (group B; n:45, age: 64 +/- 10 years). P-wave measurements were calculated from 12-lead electrocardiogram. There was no difference related to clinical characteristics. Left atrial dimension was significantly higher in group B (P =.003). P maximum (124 +/- 12 vs. 113 +/- 11 ms, P =.001) and PD (57 +/- 8 vs. 49 +/- 9 ms, P =.001) were also significantly longer in group B compared with group A, but P minimum did not. In univariate analysis, PD were related to AF duration (P =.002) and left atrial size (P =.02). This relation remained in multivariate analysis (P =.01, P =.02, respectively). P maximum >112 ms and PD >47 ms had accuracy values of 74% and 83% respectively for separating group B. Our results suggest that P wave duration and dispersion is prolonged in patients with long-term AF compared to short-term AF.