Short-term effects of fluvastatin therapy on plasma interleukin-10 levels in patients with chronic heart failure.

BACKGROUND: Experimental data demonstrated that inflammatory mediators, such as pro-inflammatory and anti-inflammatory cytokines and their receptors might have important role in the development and the progression of heart failure (HF). Statins were shown to downregulate inflammatory cytokines in HF. Interleukin (IL)-10 is one of the most important anti-inflammatory cytokines. The effect of statin therapy on plasma IL-10 levels is not known in patients with HF. We conducted this study to investigate the effects of fluvastatin therapy on plasma IL-10 cytokine concentration in patients with HF. METHODS: A total of 29 patients with ischemic HF were included in this prospective uncontrolled study. Patients were assigned to fluvastatin (80 mg/day) after baseline examinations. Determination of biochemical parameters including lipids, IL-10, and tumor necrosis factor-alpha were performed at baseline and 12 weeks after the initiation of fluvastatin therapy. All participants also underwent symptom-limited exercise tolerance test at baseline and 12 weeks, and heart rate recovery (HRR) was calculated. RESULTS: A significant elevation in the plasma levels of IL-10 after 12 weeks of fluvastatin treatment (4.8+ or -1.0 vs. 6.5+ or -1.3 pg/ml, P=0.002) was observed. Plasma tumor necrosis factor-alpha levels were significantly decreased after fluvastatin therapy (6.3+ or -2.3 vs. 4.8+ or -1.4 pg/ml, P=0.003). Fluvastatin therapy significantly improved HRR at 1 min after 12 weeks compared with baseline (19+ or -7 vs. 24+ or -9 bpm, P<0.001). A positive correlation between the change in the levels of IL-10 and the change in HRR at 1 min (r=0.57, P<0.001) was observed. CONCLUSION: Fluvastatin therapy might lead to an increase in plasma IL-10 levels and an associated improvement in vagal tonus as assessed by HRR at 1 min in patients with HF. These findings might partly explain the possible benefit observed in statin trials.

Coronary flow reserve is impaired in patients with slow coronary flow.

BACKGROUND: Slow coronary flow (SCF) in a normal coronary angiogram is a well-recognized clinical entity, but its etiopathogenesis remains unclear. However, previous studies have suggested that microvascular abnormalities and endothelial dysfunction responsible for SCF. Accordingly, we hypothesized that SCF phenomenon may be a form, at least early phase, of atherosclerosis that involve both small vessels and epicardial coronary arteries, and therefore we investigated coronary flow reserve (CFR) reflecting coronary microvascular function in patients with SCF. METHODS: Twenty subjects with SCF and 15 control subjects with normal coronary flow were studied. Coronary flow was quantified according to TIMI frame count (TFC). Coronary diastolic peak flow velocities were measured at baseline and after dipyridamole infusion. CFR was calculated as the ratio of hyperemic to baseline diastolic peak velocities. RESULTS: Demographic features, coronary risk factors, echocardiographic measurements except diastolic function parameters, and biochemical measurements were similar between the groups. CFR values were significantly lower in subjects with SCF than in the control group (1.99+/-0.38 versus 2.99+/-0.47, P<0.0001). In addition, TIMI frame count independently correlated with CFR. CONCLUSION: These findings suggest that CFR, which reflects coronary microvascular function, is impaired in patients with SCF, and corrected TFC well correlates with CFR.

Value of preoperative echocardiography in the prediction of postoperative atrial fibrillation following isolated coronary artery bypass grafting.

The value of echocardiography, especially tissue Doppler imaging (TDI), in the assessment of risk of postoperative atrial fibrillation (AF) after coronary artery bypass grafting (CABG) is not clear. One hundred two consecutive patients (80 men; mean age 61 +/- 10 years) who underwent elective isolated CABG were included in the study. All patients underwent conventional transthoracic echocardiography and TDI of the left and right heart before surgery. Also, 24-hour Holter recordings were obtained for all patients. The study end point was the development of postoperative AF. The surgical mortality rate was 2%. Postoperative AF occurred in 18 patients (18%). Patients with postoperative AF have been significantly older than patients without postoperative AF (73 +/- 7 vs 58 +/- 9 years, respectively; p <0.001). Compared with patients without postoperative AF, a significantly higher proportion of patients with postoperative AF experienced paroxysmal AF before surgery (6% vs 33%, respectively; p = 0.001). Patients with postoperative AF had a significantly larger mean left atrial diameter compared with patients without postoperative AF (37 +/- 3 vs 35 +/- 3 mm, respectively; p = 0.012). Multivariate logistic regression analysis identified age as the most significant predictor of postoperative AF (odds ratio 1.254, 95% confidence interval 1.127 to 1.396; p <0.001). Of the echocardiographic variables, only left atrial diameter was identified as a significant predictor of postoperative AF (odds ratio 1.250, 95% confidence interval 1.055 to 1.562; p = 0.047). In conclusion, in the prediction of postoperative AF after isolated CABG, preoperative transthoracic echocardiography, including both conventional echocardiography and TDI, is of little value.

Assessing coronary blood flow with TIMI frame count method in isolated myocardial bridging.

Myocardial bridging (MB) is a congenital anomaly of coronary arteries and its functional significance remains controversial. Using the TIMI frame count (TFC) method, the authors investigated whether the coronary blood flow velocity is decreased in MB. The study included 18 patients (group 1; 12 men and 6 women; mean age 50 +/-6 years) who had angiographically proven MB and otherwise normal coronary arteries and 20 subjects (group 2; 13 men and 7 women; mean age 50 +/-7 years) with normal-appearing coronary arteriograms. TFC of each group was determined and correlation between TFC and various factors including percent systolic narrowing, age, gender, body mass index, blood pressure, and echocardiographic parameters (ejection fraction, left-right ventricle wall thickness, and diameters) was investigated. Baseline characteristics were similar in the groups. All of the MB was localized to the left anterior descending (LAD) artery. Corrected TFC(LAD) frame count (CTFC) was significantly higher in group 1 than in group 2 (24.7 +/-2.1 vs 22.1 +/-1.9 frames/s, p = 0.001). Circumflex and right coronary artery frames counts were similar in the groups (22.4 +/-2.4 vs 21.3 +/-2.3 frames/s, p = 0.18, 23.1 +/-2.2 vs 23.4 +/-2.1 frames/s, p = 0.7) On correlation analysis, there was no correlation between TFC and the factors investigated. CTFC of patients with MB was higher than of those with normal coronary arteries, irrespective of the degree of systolic narrowing. This may suggest that coronary blood flow is decreased in patients with MB compared to patients having normal coronary arteries.

Comparison of different regression analyses for identifying risk factors in obese and nonobese patients with coronary artery disease.

This study was designed to assess conventional and novel risk factors in obese and nonobese patients with coronary artery disease (CAD) by using multivariate forward and univariate logistic regression analysis and to find the best model of analysis for identifying these risk factors. The study group consisted of 398 patients who consecutively underwent coronary angiography for the investigation of chest pain, except overweight patients. In univariate logistic regression analysis, high C-reactive protein and cigarette smoking were found to be the strongest variables in obese and nonobese patients with CAD, respectively. In multivariate forward logistic regression analysis, some risk factors were not found as predictors of CAD. Multivariate forward logistic regression analysis with the advantage of a high predictable ratio may be more useful for the analysis of risk factors in patients with CAD.

Effect of slow coronary flow on electrocardiographic parameters reflecting ventricular heterogeneity.

QT interval dispersion reflects regional variations in ventricular repolarization and cardiac electrical instability. Previous studies have showed that QT interval dispersion changes during episodes of myocardial ischemia. Slow coronary flow (SCF) in epicardial coronary arteries is a rare and unique angiographic finding. Whether this pattern of flow is associated with electrocardiographic abnormalities is unknown. Therefore, this study was designed to investigate whether SCF results in electrocardiographic (ECG) changes compared to normal coronary flow. For this aim 24 patients with angiographically proven SCF who had no obstructive coronary lesion (group I) and 25 patients without coronary artery disease (group II) were included in the study. Both groups underwent a routine standard 12-lead surface electrocardiogram recorded at 50 mm/s during rest. QT dispersion (QTd), corrected QT (QTc), and corrected QT dispersion (QTcd) were calculated. Distributions of sex, age, body mass index (BMI), and cardiac risk factors were similar in the 2 groups. Mean heart rate was similar in the 2 groups (74 +/-8 vs 77 +/- 7 p > 0.05). Mean QRS interval durations were similar in the groups (92 +/-7 vs 90 +/-6 ms p > 0.005). In group I, QTd, QTcd, and QTc, were significantly higher than in group II (QTd: 73 +/-14 vs 40 +/-14; QTcd: 71 +/-15 vs 42 +/-9; QTc: 414 +/-14 vs 388 +/-13, respectively p <0.05). In conclusion, SCF was found to be associated with prolonged QT interval and increased QT dispersion. Ischemia in microvascular level and/or altered autonomic regulation of the heart may be responsible mechanisms.

Increased high sensitive CRP level and its significance in pathogenesis of slow coronary flow.

Previous studies have suggested that microvascular abnormalities cause slow coronary flow (SCF). The role of inflammation has not been investigated, to date. The purpose of this study was to determine the role of inflammation in pathogenesis of SCF. The study included 32 patients with angiographically proven SCF (mean age 49 +/-9 years) (group I) and 30 subjects with normal coronary flow (mean age 48 +/-8 years) (group II). Blood samples were collected for high sensitive CRP (hs-CRP) measurements. Thrombolysis in myocardial infarction frame count (TFC) was compared in both groups. Distribution of sex, age, body mass index (BMI), arterial blood pressure, and ejection fraction were similar in the 2 groups. TFC was significantly higher in group I than in group II for each artery including left anterior descending coronary artery (LAD), left circumflex artery (Cx), and right coronary artery (RCA) (38.9 +/-6.6 vs 22.1 +/-1.8 frames, p = 0.0001; 39.6 +/-4.9 vs 22.3 +/-1.8 frames, p = 0.001 ; 39.0 +/-3.8 vs 22.0 +/-1.8 frames, p = 0.001, respectively). In group I, serum hs-CRP concentration was significantly higher than that of group II (0.6 +/-0.58 vs 0.24 +/-0.1 mg/dL p = 0.03). Correlation analysis showed a positive correlation between hs-CRP level and TFC for each artery (for CTFC(LAD), r = 0.36 p = 0.004; for TFC(Cx), r = 0.42 p = 0.003; and for TFC(RCA), r = 0.42, p = 0.0001 respectively). Increased hs-CRP level suggests that inflammation may be associated with pathogenesis of SCF or at least in part contributes to its pathogenesis. Increased hs-CRP level may also be an early marker of impaired coronary blood flow.

Endothelial nitric oxide synthase gene polymorphisms in patients with slow coronary flow.

BACKGROUND AND AIMS: The aim of this study was to explore potential associations of the intron 4 variable number of tandem repeats (VNTR) and E298A polymorphisms of the endothelial nitric oxide synthase (eNOS) gene with slow coronary flow (SCF). The association between plasma nitrate and nitrite (NO x ) concentrations and eNOS gene polymorphisms was also assessed. MATERIALS AND METHODS: The intron 4 VNTR and E298A polymorphisms of the eNOS gene were evaluated in the isolated DNA blood samples obtained from the SCF patient group (n = 30) and healthy group consisted of age- and sex-matched controls (n = 61). RESULTS: Plasma NO x level was significantly lower in patients with SCF than in controls. In addition, patients with SCF have significantly lower nitric oxide levels than control subjects within each genotype variants. The allele and genotyped frequencies of the eNOS intron 4 VNTR and E298A polymorphisms were similar between patients with SCF and the controls. Plasma NO x concentrations with respect to the relevant genotypes were found insignificant. DISCUSSION AND CONCLUSION: Plasma NO x is lower in patients with SCF than in healthy subjects. Our findings may suggest the lack of association between intron 4 VNTR and E298A polymorphisms of the eNOS gene and SCF.

Value of prolonged QRS duration as a predictor of low cardiac output syndrome in patients with impaired left ventricular systolic function who undergo isolated coronary artery bypass grafting.

This study determined whether prolonged QRS duration (QRSd; > or =120 ms) is an independent predictor of low cardiac output syndrome (LCOS) in patients with low left ventricular (LV) ejection fraction (EF) who underwent isolated coronary artery bypass grafting (CABG). Abnormal LV systolic function places patients at greater risk for developing LCOS after isolated CABG. In patients with this form of ventricular function impairment, prolonged QRSd is associated with adverse hemodynamic effects. Clinical, operative, and outcome data from 190 consecutive patients with LVEF <50% who underwent isolated CABG (mean 62 +/- 9 years of age) were retrospectively analyzed. For all patients, preoperative QRSd was determined. LCOS was the primary outcome investigated. Fifty-seven patients (30%) developed LCOS. Compared with the subgroup without LCOS, the subgroup with this syndrome had significantly larger proportions of patients with LVEF <30% and prolonged QRSd. In addition, the group that developed LCOS had a longer mean QRSd (117 +/- 25 vs 102 +/- 17 ms, respectively, p = 0.00003) and a significantly higher frequency of adverse postoperative outcomes. Hospital stay was significantly longer in the subgroup with LCOS than in the subgroup without. Multivariate logistic regression analysis identified prolonged QRSd as the most significant predictor of LCOS. LVEF <30%, diuretic therapy, and preoperative risk score (European System for Cardiac Operative Risk Evaluation) were also identified as independent predictors of LCOS. In conclusion, in patients with impaired LV systolic function, prolonged QRSd is a highly significant predictor of LCOS development after isolated CABG.

Comparison of direct stenting versus conventional stent implantation on blood flow in patients with ST-segment elevation myocardial infarction.

As compared with balloon angioplasty, stent implantation in treatment of acute myocardial infarction (AMI) reduces abrupt vessel closure, restenosis, and reocclusion rate. However, a few studies have demonstrated the safety and feasibility of direct stenting compared to conventional stent implantation technique. This study was designed to compare possible advantages of direct stenting with conventional stent implantation on immediate coronary blood flow and short-term clinical benefits in patients with AMI. Fifty patients with AMI who underwent mechanical revascularization were eligible for the study. The patients were randomly assigned to undergo either direct stenting (n = 25) or conventional stent implantation (n = 25). Before and after the procedure thrombolysis in myocardial infarction (TIMI) flow and postprocedural corrected TIMI frame count (cTFC) of the infarct-related artery were measured. There was no difference in TIMI flow distribution at baseline between the 2 groups. TIMI 3 flow rate significantly increased after procedure in both groups compared to baseline (p < 0.05). Postprocedural cTFC was found significantly lower in the direct stent arm compared to conventional stenting (p < 0.001). Both during and after the procedure the complication rate and procedural time were lower in the direct stenting arm. Direct stenting provides better immediate coronary blood flow and is a safe and feasible method compared with conventional stenting in patients with AMI. Improvement in coronary blood flow measured by the corrected TIMI frame count method may suggests a significant reduction of microvascular injury.

Contribution of plasma lipid disturbances to vascular endothelial function in patients with slow coronary flow.

Previous studies have suggested that microcirculatory abnormalities cause slow coronary flow (SCF). However, the underlying mechanism of this phenomenon has not yet been well documented. Therefore, the aim of this study was to determine the role of plasma lipid disturbances in pathogenesis of slow coronary flow (SCF). Forty patients with SCF (group I) and 37 subjects with normal coronary arteries (group II) were included in the study. In each subject plasma lipid concentrations (total cholesterol [TC], low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], and triglyceride [TG]) and brachial artery flow-mediated dilatation (FMD) and nitroglycerin (NTG)-induced dilatation were measured. Total cholesterol level was found to be similar in the 2 groups. In group I, HDL-C level was lower than in group II (34 +/-3 vs 40 +/-4 mg/dL, p=0.0001). In group I, TG level was higher than in group II (213 +/-29 vs 198 +/-24 mg/dL p=0.002). In group I, FMD was smaller than that of group II (3.48 +/-3.1% vs 10.4 +/-5.6%, p=0.0001). The percent NTG-induced dilatation was not different between the groups (15.5 +/-5.3% vs 17.3 +/-6.9%, p=0.27). On regression analysis; there was a significant relationship between percent of FMD and HDL-C (r =0.65, p=0.0001). When the 2 groups were analyzed separately, HDL-C was still related to percent of FMD in both groups (r =0.47 p=0.002 and r =0.45 p=0.005, respectively). Multivariate regression analysis showed that only plasma HDL-C was independently related to FMD (F=7.5 p=0.0001). In patients with SCF, reduced flow-mediated dilatation was detected and was found to be associated with plasma lipid disturbances, principally low HDL and high TG levels.

An experience on radial versus femoral approach for diagnostic coronary angiography in Turkey.

OBJECTIVE: The radial approach has been increasingly used as an alternative to femoral access. The purpose of the present study was to assess the feasibility, success, and safety of the transradial approach (TRA) for diagnostic coronary angiography, and to describe the difficulties associated with the technique as compared with transfemoral approach (TRF). METHODS: A series of 180 consecutive patients were divided to TRA or TFA groups by two operators. We compared the groups regarding procedural time, access time, fluoroscopy time, procedural failure, complications, contrast volume, length of hospital stay, and number of used coronary catheters. RESULTS: The number of used coronary catheters was not different between the two groups (p = 0.6). Total hospital length of stay was significantly shorter in the radial group (p <0.0001) than in femoral one. We found differences between the radial and femoral groups in the success rate (p<0.0001), contrast volume (p = 0.012), procedural time (p<0.0001), access time (p<0.0001), and fluoroscopy time (p<0.0001). We did not find any major complication in the radial group. There was a major bleeding in the femoral group. CONCLUSION: The TRA is a safe alternative to femoral catheterization although with lesser procedural success, longer procedural access, and radiation time, and more contrast volume.

Comparison of carotid intima-media thickness in patients with stable angina pectoris versus patients with acute coronary syndrome.

In this study, we found that carotid intima-media thickness (IMT) was significantly increased and carotid artery atherosclerotic plaques were detected more frequently in patients who had early-onset coronary artery disease compared with control subjects (0.73 +/- 0.10 vs 0.60 +/- 0.10 mm, p <0.001, and 40% vs 11%, p <0.001, respectively). Further, patients who had coronary artery disease and presented with an acute coronary syndrome were found to have significantly increased carotid IMT compared with patients who had stable angina pectoris (0.76 +/- 0.10 vs 0.70 +/- 0.10 mm, p <0.05). The IMT was greater in the patients who had acute coronary syndrome than in those who had stable angina pectoris.

Elevated plasma homocysteine level in slow coronary flow.

BACKGROUND: Slow flow velocity of dye in coronary arteries is not an infrequent finding during routine coronary angiography and its precise mechanism is unknown. In this study, we measured the plasma homocysteine level in patients with slow coronary flow (SCF) in comparison with subjects having normal coronary flow (NCF). METHOD: The study consisted 39 patients (mean age, 47+/-8 years) with angiographically diagnosed SCF. SCF was defined according to TIMI frame count (TFC) method. Thirty subjects (mean age 46+/-8 years) with NCF served as control group. Plasma homocysteine levels were measured after 12 h fasting period in each subject. RESULTS: Baseline demographic properties were similar in both groups. In patients with SCF, TFC was significantly higher than those with NCF. Similarly, in patients with SCF plasma homocysteine level was significantly higher than that of control group (14.1+/-2.2 vs. 5.5+/-1.3 micromol/l, respectively p < 0.001). CONCLUSION: Elevated plasma homocysteine level supports the hypothesis that endothelial function is impaired in slow coronary flow.

Impaired left ventricle filling in slow coronary flow phenomenon: an echo-Doppler study.

Slow coronary flow (SCF) in a normal-appearing coronary angiogram is a well-recognized clinical entity, but its etiopathogenesis remains unclear. The aim of the study was to evaluate echocardiographic features in patients with SCF. Thirty-four patients with angiographically proven SCF (group I) and 25 patients with normal coronary flow (group II) were enrolled in the study. The diagnosis of SCF was made with use of the "TIMI frame count (TFC)'' method. All patients underwent complete transthoracic echocardiographic examination (M-mode, 2-dimensional [2-D], and Doppler parameters such as color, continuous, pulsed wave). There were no significant differences with respect to systolic parameters between the 2 groups; in spite of these, group I showed impaired left ventricular diastolic patterns compared to group II. Group I patients had higher peak late diastolic filling velocities due to enhanced atrial systole (A), lower peak (E/A) diastolic filling velocity ratios, and longer isovolumetric relaxation times compared with group II, and these were statistically significant (p<0.001). In conclusion; the authors detected diastolic filling abnormalities and showed diastolic dysfunction in patients with SCF.

Determination of risk factors in obese and non-obese patients with coronary artery disease.

OBJECTIVE: Obesity is a complex multifactorial chronic disorder recently classified by the American Heart Association (AHA) as a modifiable risk factor for coronary artery disease (CAD). This study was designed to assess conventional and novel risk factors in obese and non-obese patients with CAD. METHODS AND RESULTS: This study evaluates the association between conventional and novel coronary risk factors and CAD in obese and non-obese patients by using multivariate stepwise logistic regression analysis. The obese CAD group was identified by the following predictors of CAD: age, sex, hypertension, diabetes mellitus, smoking, family history of CAD, low level of HDL cholesterol, high LDL cholesterol, high C-reactive protein, high homocysteine. In a non-obese CAD group, the identified predictors of CAD were age, sex, hypertension, smoking, family history of CAD, levels of high C-reactive protein, and high homocysteine. Hypertension was found to be the strongest predictor for both obese (OR: 39.91, 95% confidence intervals (CI): 5.5 1-280.3, p < 0.001) and non-obese (OR: 14.39, 95% CI: 4.4-25.8, p < 0.001) patients with CAD. CONCLUSIONS: From our data, we conclude that hypertension appears to be the strongest independent predictor of CAD regardless of body mass index (BMI).

Vascular endothelial function in patients with slow coronary flow.

BACKGROUND: Slow coronary flow (SCF) in a normal coronary angiogram is a well-recognized clinical entity, but its etiopathogenesis remains unclear. DESIGN: The aim of the study was to determine endothelial function in patients with SCF using a flow-mediated dilatation (FMD) technique in the brachial artery. METHODS: Coronary flow was quantified using the corrected thrombosis in myocardial infarction (TIMI) frame count (CTFC) method. Endothelial function was studied in 27 patients with SCF (23 men, four women, mean age 47.6+/-8.7 years) and in 30 people with normal coronary flow (NCF) (22 men and eight women, mean age 47.5+/-7.4 years). RESULTS: The flow-mediated diameter increase in the SCF group was significantly smaller than that in the NCF group (3.48+/-0.10% compared with 9.11+/-0.10%, P < 0.001). The percentage of nitroglycerine (NTG)-induced dilatation was not significantly different between patients with SCF and people with NCF (16.8+/-1.1% compared with 17.1+/-1.1%, P = 0.87). Simple regression analysis showed that mean CTFC (CTFC(m)) was strongly and inversely related to the percentage of FMD (r = -0.29, P < 0.01) in all participants. When the patients with SCF were excluded, CTFC(m) was still inversely related to the percentage of FMD (r = -0.36, P < 0.05). CTFC(m) was also inversely related to NTG-induced dilatation in the 57 participants (r = -0.23, P < 0.05). Multiple regression analysis showed that CTFC(m) was inversely related to the percentage of FMD only (r = -0.37, P < 0.05). CONCLUSIONS: These findings suggest that endothelial function is impaired in people with SCF and that CTFC correlates well with endothelial dysfunction.

Exercise-induced changes in QT interval duration and dispersion in patients with isolated myocardial bridging.

BACKGROUND: Isolated myocardial bridging (MB) often is considered to be an unimportant angiographic finding; however, its association with cardiovascular event has been shown. In this study we aimed to assess exercise-induced electrocardiographic (ECG) changes and susceptibility to arrhythmia in patients with MB. METHOD: 21 consecutive patients who had angiographically proven MB (group I) and 25 subjects (group II) who had normal coronary arteries underwent exercise test using Bruce protocol. Before and after the exercise test the changes in QT interval duration and dispersion were compared. RESULTS: Baseline characteristics of both groups were similar. Heart rate significantly increased after exercise test in both groups. In group I, after exercise mean QT(max) and QT(min) durations did not change significantly compared to baseline values, respectively. (QT(max): 411+/-20 vs. 421+/-18 ms, p>0.05 and QT(min): 380+/-12 vs. 378+/-10 ms, p>0.05). However, following exercise test QT dispersion (QT(d)) and corrected QT dispersion (QT(cd)) significantly increased when compared to baseline values, respectively. (34+/-13 vs. 66+/-14 ms, p<0.05 and 37+/-14 vs. 69+/-17 ms, p<0.05) On the other hand, in control group QT(max) and QT(min) durations, QT(c) and QT(cd) did not change significantly compared to baseline values, respectively. (QT(max): 408+/-18 vs. 412+/-17 ms, p>0.05 and QT(min): 390+/-11 vs. 387+/-10 ms, p>0.05; QT(d): 25+/-14 vs. 31+/-16 ms, p>0.05; QT(cd): 27+/-15 vs. 33+/-17 ms, p>0.05). CONCLUSION: Treadmill exercise test significantly increased QT dispersion in patients with MB. This increase may result from exercise-induced ischemia at the area perfused by bridged artery.

Identifying risk factors in a mostly overweight patient population with coronary artery disease.

Overweight/obesity is a complex multifactorial chronic disorder, and the American Heart Association (AHA) has recently classified as a modifiable risk factor for coronary heart disease (CAD). This study (1) evaluates the association between CAD in a patient population mostly overweight (MOP) and conventional and novel coronary risk factors by using univariate and multivariate logistic regression analysis and (2) seeks to find the best model by comparing univariate and multivariate logistic regression analysis algorithms, which were systematically applied to risk factors by using Hosmer-Lemeshow statistic test. In univariate analysis, there were significant associations between CAD in MOP and conventional and novel risk factors. However, the model's sensitivity, specificity, and accuracy levels were weak. In multivariate analysis, although some risk factors were not found as predictors of coronary artery disease, the model showed good fit to data and had high sensitivity, specificity, and accuracy levels. This was also confirmed by using the Hosmer-Lemeshow goodness of fit test, more specifically.

Evaluation of blood rheology in patients with coronary slow flow or non-obstructive coronary artery disease.

Coronary slow flow (CSF) has been documented in 25% of patients evaluated for angina or angina-like chest pain, despite the presence of normal epicardial coronary arteries on angiography. The risk for the development of clinical events in patients with non-obstructive coronary artery disease (NOCAD) is higher than in patients with completely normal coronary arteries. The object of this study was to evaluate changes in blood and plasma viscosity in patients with CSF or NOCAD. The study included 147 subjects (CSF, n = 42, NOCAD, n = 42 and controls, n = 63). Blood and plasma viscosity, complete blood counts, fibrinogen, and high sensitivity C-reactive protein (hs CRP) levels were measured. There was no significant difference between the groups with respect to blood and plasma viscosity (p > 0.05). Hemoglobin, hematocrit, and erythrocyte counts were significantly higher in the CSF group compared to the NOCAD group (p = 0.017, p = 0.023 and p = 0.023 respectively) and the control group (p = 0.026, p = 0.02 and p = 0.02, respectively). High sensitivity CRP levels in the NOCAD group were higher than the CSF group and the control group (p = 0.001 and p = 0.018, respectively). In conclusion, no significant difference was observed in the blood and plasma viscosity in patients with CSF or NOCAD. Increases in hemoglobin and hematocrit values without an increase in viscosity may play a role in the pathophysiology of CSF.