Abdullah Dogan

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.

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.

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.

The effects of continuous positive airway pressure therapy on mean platelet volume in patients with obstructive sleep apnea

Previous studies have reported increased platelet activation and aggregation in patients with obstructive sleep apnea (OSA). Continuous positive airway pressure (CPAP) treatment has been shown to decrease platelet activation. We aimed to study the effects of nasal CPAP therapy has on MPV values in patients with severe OSA. Thirty-one patients (21 men; mean age 53.8 ± 9.2 years) with severe OSA (AHI > 30 events/hour) constituted the study group. An age, gender and body mass index (BMI) matched control group was composed 25 subjects (14 men; mean age 49.6 ± 8.5 years) without OSA (AHI < 5 events/hour). We measured MPV values in patients with severe OSA and control subjects and we measured MPV values after 6 months of CPAP therapy in severe OS patients. The median (IQR) MPV values were significantly higher in patients with severe OSA than in control group (8.5 [8.3–9.1] vs. 8.3 [7.5–8.8] fL; p = 0.03). The platelet counts were significantly lower in patients with severe OSA than in control group (217.8 ± 45.9 vs. 265.4 ± 64.0 × 109/L; p = 0.002). The six months of CPAP therapy caused significant reductions in median (IQR) MPV values in patients with severe OSA (8.5 [8.3–9.1] to 7.9 [7.4–8.2] fL; p < 0.001). Six months of CPAP therapy caused significant increase in platelet counts when compared with baseline values (217.8 ± 45.9 to 233.7 ± 60.6 × 109/L; p < 0.001). We have found that the MPV values of patients with severe OSA were significantly higher than those of the control subjects and 6 months CPAP therapy caused significant reductions in the MPV values in patients with severe OSA.

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.

Metoprolol vs. carvedilol or carvedilol plus N-acetyl cysteine on post-operative atrial fibrillation: a randomized, double-blind, placebo-controlled study

AIMS Carvedilol and N-acetyl cysteine (NAC) have antioxidant and anti-inflammatory properties. Aim was to evaluate the efficacy of metoprolol, carvedilol, and carvedilol plus NAC on the prevention of post-operative atrial fibrillation (POAF). METHODS AND RESULTS Patients undergoing cardiac surgery (n = 311) were randomized to metoprolol, carvedilol, or carvedilol plus NAC. Baseline characteristics were similar. The incidence of POAF was lower in the carvedilol plus NAC group compared with the metoprolol group (P < 0.0001) or the carvedilol group (P = 0.03). There was a borderline significance for lower POAF rates in the carvedilol group compared with the metoprolol group (P = 0.06). Duration of hospitalization was lower in the carvedilol plus NAC group compared to the metoprolol group (P = 0.004). Multivariate independent predictors of POAF included left-atrial diameter, hypertension, bypass duration, pre-randomization and pre-operative heart rates, carvedilol plus NAC group vs. metoprolol group, and carvedilol plus NAC group vs. carvedilol group. CONCLUSION Carvedilol plus NAC decreased POAF incidence and duration of hospitalization compared with metoprolol and decreased POAF incidence compared with carvedilol.

Gamma-glutamyltransferase in acute coronary syndrome patients without ST elevation and its association with stenotic lesion and cardiac events.

BackgroundThere are limited data on prognostic value of gamma-glutamyltransferase (GGT) in acute coronary syndromes (ACS) with non-ST-segment elevation (NSTE-ACS). We investigated GGT levels and their association with significant stenosis and major cardiac events (MACE) in NSTE-ACS patients. Methods and resultsThis study included 237 patients with NSTE-ACS (ACS group), and age-matched and sex-matched controls with normal coronary arteries (control group). ACS group was divided into subgroups with and without significant stenosis. Serum creatine kinase-MB, troponin T and GGT levels were measured. ACS patients were followed up for MACE (composite of cardiac death, myocardial infarction, recurrent angina, and hospitalization) during 12 months. Median GGT level was higher in ACS group than control group (32 vs. 16 U/l, P=0.001). NSTE-ACS was independently associated with hypertension [odds ratio (OR): 2.83, P=0.001], smoking (OR: 2.19, P=0.015), GGT [OR: 1.16, 95% confidence interval (CI): 1.11–1.21, P=0.001] and ejection fraction (OR: 0.92, P=0.01). GGT level was also higher in patients with significant stenosis than those without significant stenosis (37 vs. 22 U/l, P=0.001). Presence of significant stenosis was independently associated with GGT level (OR: 1.17, 95% CI: 1.12–1.23, P=0.001). At 12 months, MACE-free survival was slightly poor in ACS patients with upper GGT tertile compared with those with lower GGT tertile (77 vs. 97%, P=0.06). ConclusionIn NSTE-ACS patients, increased GGT levels can be associated with significant stenosis and MACE.