Shih-Tai Chang

Changes of the Cardiac Architectures and Functions for Chronic Hemodialysis Patients with Dry Weight Determined by Echocardiography

Background/Aims: Left ventricular hypertrophy (LVH) has long been known as an independent risk factor for cardiovascular deaths, in both dialysis and general populations. Numerous factors influence the pathophysiology of LVH. However, extracellular fluid may have a particularly important influence on this impact. Inferior vena cava diameter (IVCD) estimation is a non-invasive and relatively convenient method for obtaining a good correlation with the intravascular fluid status, and may obtain an optimal dry weight (DW) for chronic hemodialysis patients. This study estimates the DW of end-stage renal disease (ESRD) patients by echocardiographic measurement of the IVCD to observe changes in cardiac morphology and function. Methods: A total of 88 patients, ranging from 26 to 90 (59.4 ± 13.3) years of age, were involved in this study. The patients were divided into study (n = 48) and control (n = 40) groups. All patients received IVCD assessment via echocardiography bi- monthly for 1 year. In the study group patients, DW was adjusted according to the IVCD by echocardiography. Meanwhile, in the control group patients, DW was adjusted based on traditional clinical parameters. All patients underwent cardiac examinations and measurements, including left ventricular mass (LVM), wall thickness, chamber size and left ventricular systolic function by echocardiography, at the beginning and end of the study. Results: Both groups displayed comparable clinical and biochemical parameters. The IVCD index correlated well with the cardiac parameters estimated by echocardiography. The LVM and left ventricular mass index (LVMI) was reduced significantly in the study group patients (from 200 ± 64.2 to 187 ± 63.2 g, p = 0.021; from 132 ± 37.6 to 123 ± 37.3 g/m2, p = 0.014, respectively). Furthermore, the study group patients with fluid overload, named study subgroup A, displayed significant differences not only in LVM and LVMI, but also in septal wall thickness, left ventricular end-diastolic dimension and left atrial dimension. In contrast, the control group displayed no changes in these cardiac architectures during the study period. Conclusion: Adjusting DW via the IVCD measured by echocardiography for hemodialysis patients may prevent the progression of chamber dilatation and LVH, especially for patients with fluid overload.

Independent Determinants of Coronary Artery Disease in Erectile Dysfunction Patients

INTRODUCTION There is growing evidence of a link between erectile dysfunction (ED) and coronary artery disease (CAD). AIMS The purpose of this study was to explore the independent determinants of CAD in ED outpatients. METHODS This study enrolled 243 patients, ranging in age from 21 to 81 years old, suffering from ED as diagnosed by the International Index of Erectile Function (IIEF) scores. All patients underwent exercise stress tests or thallium-201 single-photon emission computed tomography perfusion imagings. Based on examination results, patients were divided into study (22 patients with a positive finding) and control groups (221 patients with a negative finding). MAIN OUTCOME MEASURES The differences of demographic characteristics, biochemical profiles, pro-inflammatory and inflammatory markers, and echocardiographic characteristics between study and control group were compared. RESULTS The age, presence of DM and current smoking status were significant high in the study group. A significant lower high-density lipoprotein (HDL) cholesterol level, a higher percentage of HDL cholesterol level < 40 mg/dL, and a higher apo-lipoprotein B/A1, high sensitive C-reactive protein (hs-CRP) and homocysteine found in the study group. The Framingham cardiac risk scores, the ratio of mitral inflow velocity to early diastolic velocity in the annulus derived by tissue Doppler imaging (E/Et), the ratio of E/Et > or = 15, the value of carotid intima-media thickness (IMT), and IMT > or = 1 mm were higher in study group than in the control group. In stepwise multiple logistic regression analysis, a high waist-to-hip ratio (WHR), high IMT, high E/Et, hs-CRP levels, LDL cholesterol > or = 130 mg/dL, smoking status, and the presence of DM and metabolic syndrome (MS) were independent determinants of CAD in ED patients. CONCLUSIONS This study first shows the independent determinants of CAD in ED outpatients. This novel finding may improve the screening of low-risk ED patients for CAD.

Aortic valve sclerosis is an echocardiographic indicator of significant coronary disease in patients undergoing diagnostic coronary angiography

Aortic valve sclerosis (AVS) is considered to be a manifestation of generalised atherosclerosis that involves the aortic valve. It has been associated with higher cardiovascular morbidity and mortality in a population‐based study. This investigation used transthoracic echocardiography (TTE) to evaluate the prevalence and significance of AVS in 357 Chinese patients with suspected coronary artery disease (CAD). This work reveals that AVS is an independent echocardiographic predictor of significant CAD in such clinical setting (O.R. = 3.18; 95% confidence interval 1.52–6.7; p = 0.002). Other independent predictors include male gender, diabetes mellitus and hypertriglyceridemia. The predictive value of AVS for the presence of CAD is more prominent in females and in subjects aged <65 years. The recognition of AVS on TTE should alert the physicians to the possibility of underlying significant CAD, and further evaluation with aggressive management is indicated, even though no angiographic documentation is available.

Arterial Stiffness Is the Independent Factor of Left Ventricular Hypertrophy Determined by Electrocardiogram

Introduction:Arterial stiffness may contribute to left ventricular hypertrophy (LVH). This study was conducted to evaluate the independent factor of LVH and the quantification of LVH by electrocardiogram (ECG) to predict the degree of aortic stiffness using brachial-ankle pulse wave velocity (baPWV) in subjects with hypertension. Materials and Methods:A total of 984 consecutive patients who were diagnosed as having essential hypertension were entered into the study. baPWV determination, ECG and blood sampling were performed after a 12-hour overnight fast. LVH was diagnosed using electrocardiography; Romhilt-Estes point score was subsequently calculated. Participants were separated into LVH and non-LVH groups. Additional factors associated with LVH were examined using multivariate analyses. Results:The non-LVH groups were younger (P = 0.001), had less men (P = 0.001), lower systolic and diastolic blood pressure and pulse pressure (P < 0.001 for each) and lower baPWV (P < 0.001). Stepwise multiple logistic regression analysis demonstrated that sex, age, systolic blood pressure and baPWV are independent factors. Using a baPWV value of 1825 cm/sec, the area under the receiver operating characteristic curve was 0.644 and the highest discriminating sensitivity and specificity were 60% and 65%, respectively. Conclusion:Aortic stiffness may be related to electrocardiographically determined LVH in patients with hypertension. Thus, stiffening of large arteries, together with increased systolic blood pressure, seems to significantly contribute to the pathogenesis of LVH. Quantification of LVH by ECG can also predict the degree of aortic stiffness.

Quantification of Aortic Stiffness to Predict the Degree of Left Ventricular Diastolic Function

Introduction:The association between the arterial stiffness and the severity of left ventricular (LV) diastolic function in hypertension has not been fully evaluated. This study was conducted to evaluate the relationship of aortic stiffness by brachial-ankle pulse wave velocity (baPWV) to parameters reflecting the atherosclerosis and the severity of LV diastolic function in patients with hypertension. Methods:LV ejection fraction, the ratio of peak velocity of early rapid filling and peak velocity of atrial filling (E/A ratio) and LV mass index were determined with echocardiography in 800 patients with hypertension. LV diastolic function was estimated by pulsed-tissue Doppler imaging (TDI) echocardiography, averaging diastolic mitral annular velocity measurements (Emav, Amav and Emav/Amav ratio) from 2 separate sites (basal septal and lateral). The baPWV was measured by the volume rendering method. Results:Stepwise multiple logistic regression analysis demonstrated that the independent factors of LV diastolic function were deceleration time, baPWV, age and Emav/Amav ratio. The receiver- operator characteristic curve demonstrated a baPWV of 1566 cm/sec was useful to discriminate mild LV diastolic dysfunction (sensitivity, 78%; specificity, 78%), and that a baPWV of 1730 cm/sec was useful to discriminate moderate LV diastolic dysfunction (sensitivity, 73%; specificity, 57%). Conclusions:Increased baPWV relates not only to the parameters reflecting atherosclerosis but also to those reflecting LV diastolic dysfunction. TDI-detected LV diastolic dysfunction is accompanied by increased aortic stiffness in essential hypertension. Therefore, quantification of aortic stiffness can predict the degree of LV diastolic function.

Scrutiny of cardiovascular risk factors by assessing arterial stiffness in erectile dysfunction patients

PurposeErectile dysfunction (ED) is an early sign of vascular dysfunction. Studies have reported a correlation between arterial stiffness and cardiovascular events. The objective of this study was to evaluate the association among different criteria for assessing arterial stiffness and cardiovascular risk factors in ED patients.MethodsAssessment of pulse wave velocity (PWV), pulse pressure (PP), ratio of mitral inflow velocity to early diastolic velocity in the annulus derived by tissue Doppler imaging (E/Et), and intima-medial thickness (IMT) were performed in 200 ED patients.ResultsLinear statistical analysis of the coronary artery disease risk factors revealed that PWV, PP and E/Et were positively correlated with age, duration of diabetes mellitus (DM), and systolic and diastolic blood pressures. PWV and E/Et were positively correlated with waist circumference and number of metabolic syndrome (MS) components. For category-wise analysis, the PWV, PP and E/Et were higher in patients with DM, hypertension and MS. Multiple regression analysis showed that the independent determinants for PWV comprised age, DM, hypertension, and MS; for PP comprised age, hypertension, and MS; for E/Et comprised age and MS; and for IMT comprised only DM.ConclusionsThus, PWV, PP and E/Et may be employed as markers to identify ED patients with potential cardiovascular risk factors, including MS and obesity.

Coronary Phenotypes in Patients with Erectile Dysfunction and Silent Ischemic Heart Disease: A Pilot Study

INTRODUCTION Accumulated evidence shows that erectile dysfunction (ED) may be a precursor of coronary artery disease (CAD). AIMS The purpose of this study was to explore the differences in coronary phenotypes between patients with ED and patients with angina pectoris. METHODS The study enrolled 30 ED patients (study group) and 120 age-matched angina patients who had no ED (control group). All patients had angiographically documented CAD. MAIN OUTCOME MEASURES The differences in demographic characteristics, biochemical profiles and coronary characteristics between the study and control groups were compared. RESULTS Diabetes mellitus (DM) and obesity defined by body mass index were more common in the study group than in the control group. The mean number of lesions and mean number of vessels with evidence of CAD were significantly different between the study and control groups (2.3 ± 0.1 vs. 2.2 ± 0.1, P < 0.001; 2.0 ± 0.2 vs. 1.8 ± 0.1, P < 0.001). The distribution of vessel involvement was similar between the groups, except for more common involvement of the ramus in the study group. There were no differences in distribution of lesion sites between the two groups. The control group had a higher percentage of type A stenotic lesions than the study group (16.3% vs. 2.9%, P = 0.004). Significant differences were also observed in type C lesions (52.9% in study group vs. 38.0% in control group, P = 0.026). Fewer calcified, irregular, and bifurcated lesions were present in the study group compared to control. CONCLUSIONS This study documented coronary phenotypes in ED patients without symptomatic CAD. Although the artery size hypothesis and ED had well been thought to be a precursor of CAD, the severity of coronary lesions in these patients was not more benign than that observed in angina pectoris patients who have no ED.

Relationship between resistant hypertension and arterial stiffness assessed by brachial-ankle pulse wave velocity in the older patient

Background Resistant hypertension (RH) is a common clinical condition associated with increased cardiovascular mortality and morbidity in older patients. Several factors and conditions interfering with blood pressure (BP) control, such as excess sodium intake, obesity, diabetes, older age, kidney disease, and certain identifiable causes of hypertension are common in patients resistant to antihypertensive treatment. Arterial stiffness, measured by brachial-ankle pulse wave velocity (baPWV), is increasingly recognized as an important prognostic index and potential therapeutic target in hypertensive patients. The aim of this study was to determine whether there is an association between RH and arterial stiffness. Methods This study included 1,620 patients aged ≥65 years who were referred or self-referred to the outpatient hypertension unit located at a single cardiovascular center. They were separated into normotensive, controlled BP, and resistant hypertension groups. Home BP, blood laboratory parameters, echocardiographic studies and baPWV all were measured. Results The likelihood of diabetes mellitus was significantly greater in the RH group than in the group with controlled BP (odds ratio 2.114, 95% confidence interval [CI] 1.194–3.744, P=0.010). Systolic BP was correlated in the RH group significantly more than in the group with controlled BP (odds ratio 1.032, 95% CI 1.012–1.053, P=0.001). baPWV (odds ratio 1.084, 95% CI 1.016–1.156, P=0.015) was significantly correlated with the presence of RH. The other factors were negatively correlated with the existence of RH. Conclusion In patients aged ≥65 years, the patients with RH have elevated vascular stiffness more than the well controlled hypertension group. baPWV increased with arterial stiffness and was correlated with BP levels. Strict BP control is necessary to prevent severe functional and structural vascular changes in the course of hypertensive disease.

Role of ankle-brachial pressure index as a predictor of coronary artery disease severity in patients with diabetes mellitus

BACKGROUND Previous studies have reported a close correlation between low ankle-brachial pressure index (ABPI) and various cardiovascular risk factors. However, despite the well-established potential hazards of consequent coronary artery disease (CAD), no data exist on the relationship between ABPI and the severity of CAD, particularly in patients with diabetes mellitus (DM). METHODS A total of 840 patients ranging from 35 to 87 years of age (mean [+/- SD] 63.9+/-10.2 years) with suspected CAD in a clinical practice were enrolled. All patients underwent ABPI measurements and coronary angiography. Patients were divided into four groups according to the results of ABPI measurements and the presence or absence of DM: group A had an ABPI value of at least 0.9 but no DM (A-/D-); group B had an ABPI value of at least 0.9 and DM (A-/D+); group C had an ABPI of less than 0.9 but no DM (A+/D-); and group D had an ABPI value of less than 0.9 and DM (A+/D+). RESULTS Age was significantly higher in the A+ (groups C and D) than the A- patients (groups A and B). Moreover, men predominated in all four groups. Comparisons of sex distribution among the four groups revealed that group D had the highest percentage of women, while group A had the lowest. Total cholesterol level did not differ among the four groups, although group D tended to have the highest result. Patients in group D had the highest percentages of hypertension, hypercholesterol, hypertriglyceride, low high-density lipoprotein cholesterol and high low-density lipoprotein cholesterol among the four groups. Group D exhibited the highest triglyceride and uric acid levels, the lowest high-density lipoprotein cholesterol level, and the highest metabolic syndrome criteria number and percentage of metabolic syndrome. Furthermore, group D had the highest mean lesion numbers, mean numbers of target vessel involvement, stenoses with type C classification and complex morphology lesions (chronic total occlusion, diffuse or calcified lesions) among the four groups. There were still significant differences in lesion numbers (P<0.001) and numbers of target vessel involvement (P<0.001) for ABPI predicting CAD severity after controlling for the effects of DM and age. The sensitivity, specificity, positive predictive value and negative predictive value of using an ABPI of less than 0.9 to predict CAD differed significantly between patients with and without DM. CONCLUSIONS ABPI is a useful noninvasive tool for predicting CAD severity, even in patients with DM.

Impact of Pacemaker Lead Characteristics on Pacemaker Related Infection and Heart Perforation: A Nationwide Population-Based Cohort Study

Background Several risk factors for pacemaker (PM) related complications have been reported. However, no study has investigated the impact of lead characteristics on pacemaker-related complications. Methods and Results Patients who received a new pacemaker implant from January 1997 to December 2011 were selected from the Taiwan National Health Insurance Database. This population was grouped according to the pacemaker lead characteristics in terms of fixation and insulation. The impact of the characteristics of leads on early heart perforation was analyzed by multivariable logistic regression analysis, while the impact of the lead characteristics on early and late infection and late heart perforation over a three-year period were analyzed using Cox regression. This study included 36,104 patients with a mean age of 73.4±12.5 years. In terms of both early and late heart perforations, there were no significant differences between groups across the different types of fixation and insulations. In the multivariable Cox regression analysis, the pacemaker-related infection rate was significantly lower in the active fixation only group compared to either the both fixation (OR, 0.23; 95% CI, 0.07–0.80; P = 0.020) or the passive fixation group (OR, 0.26; 95% CI, 0.08–0.83; P = 0.023). Conclusions There was no difference in heart perforation between active and passive fixation leads. Active fixation leads were associated with reduced risk of pacemaker-related infection.