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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. [ABSTRACT FROM AUTHOR]

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 I!). 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 CTFCL4D, r=0.36 p =0.004; for TFCCx, r=0.42 p=0.003; and for TFCRCA, 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. [ABSTRACT FROM AUTHOR]

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 QI (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. [ABSTRACT FROM AUTHOR]

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 TFCLAD 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. [ABSTRACT FROM AUTHOR]

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 1, 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 11 (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. [ABSTRACT FROM AUTHOR]

As compared with balloon angioplasty, stent implantation in treatment of acute myocardial infarction (AMI) reduces abrupt vessel closure, restenosis, and reocciusion 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 TIM! frame count method may suggests a significant reduction of microvascular injury. [ABSTRACT FROM AUTHOR]

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 1) and 25 patients with normal coronary flow (group II) were enrolled in the study. The diagnosis of SCF was made with use of the "TIMl 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 1 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 detecteddiastolic filling abnormalities and showed diastolic dysfunction in patients with SCF. [ABSTRACT FROM AUTHOR]