Mean Diastolic Velocity Research Articles

Fetal ductal constriction caused by maternal ingestion of green tea in late pregnancy: an experimental study

The aim of this study was to test the hypothesis that experimental maternal intake of green tea in late pregnancy causes fetal ductus arteriosus constriction, probably because of prostaglandin inhibition. Twelve fetal lambs (pregnancy > 120 days) were assessed before and after maternal administration of green tea (n = 8) or water (n = 4; controls) as the only source of liquid. After 1 week, echocardiography showed signs of constriction of the ductus arteriosus in all fetuses from mothers ingesting green tea, with increase in mean systolic velocity(from 0.70 ± 0.19 m/s to 0.92 ± 0.15 m/s, 31.4%, p = 0.001) and mean diastolic velocity (0.19 ± 0.05 m/s to 0.31 ± 0.01 m/s, 63.1%, p < 0.001), decrease of pulsatility index (2.2 ± 0.4 to 1.8 ± 0.3, 22.2%, p = 0.003) and increase of mean right ventricular/left ventricular diameter ratio (0.89 ± 0.14 to 1.43 ± 0.23, 60.6%, p < 0.001). In the four control fetuses, there were no significant changes. All lambs exposed to green tea also showed at autopsy dilated and hypertrophic right ventricles, which was not present in control fetuses. Histological analysis showed a significantly larger mean thickness of the medial avascular zone of the ductus arteriosus in fetuses exposed to green tea than in controls (747.6 ± 214.6 µm vs 255.3 ± 97.9 µm, p < 0.001). This study in fetal lambs shows a cause and effect relationship between experimental maternal exposure of green tea and fetal ductus arteriosus constriction in late pregnancy.

Preliminary observations of passive exercise using whole body periodic acceleration on coronary microcirculation and glucose tolerance in patients with type 2 diabetes

BackgroundThe whole body periodic acceleration (WBPA) system was recently developed as a passive exercise device by providing increased pulsatile shear stress for improvement of endothelial function. This study aimed to investigate the acute effects of WBPA on coronary microcirculation and glucose tolerance in patients with type 2 diabetes (T2D). MethodsThe study subjects were 8 patients with T2D who underwent transthoracic Doppler echocardiography for the assessment of coronary flow reserve (CFR) before and immediately after a 45-min session of WBPA. The flow velocity in the distal portion of the left anterior descending coronary artery was measured at baseline and during adenosine infusion. The CFR represented the ratio of hyperemic to basal mean diastolic flow velocity. ResultsWBPA increased CFR from 2.3±0.3 to 2.6±0.4 (p=0.02). WBPA decreased serum insulin level from 26±19μIU/ml to 19±15μIU/ml (p=0.01) and increased total adiponectin from 11.6±7.3μg/ml to 12.5±8.0μg/ml (p=0.02) and high molecular weight adiponectin from 4.9±3.6μg/ml to 5.3±3.9μg/ml (p=0.03), whereas the serum glucose level was stable from 207±66mg/dl to 203±56mg/dl (p=0.8). ConclusionsThis study demonstrates that a single session of WBPA treatment simultaneously improved coronary microcirculation and glucose tolerance in patients with T2D.

Analysis of coronary flow haemodynamics in homozygous familial hypercholesterolaemic adolescents with aortic supravalvular stenosis

To study coronary artery haemodynamics in adolescents with homozygous familial hypercholesterolaemia and aortic supravalvular stenosis. Patients diagnosed with familial hypercholesterolaemia who were younger than 16 years and who had undergone transthoracic echocardiography from 2007 to 2010 were included in this study. We included patients with homozygous familial hypercholesterolaemia and aortic supravalvular stenosis and those with heterozygous familial hypercholesterolaemia. All patients underwent stress echocardiography, and left anterior descending coronary artery flow was successfully detected. Coronary flow velocity reserve was calculated as the ratio of hyperaemic mean diastolic flow velocity after injection of adenosine to basal mean diastolic flow velocity. Changes in coronary haemodynamics and the relationship between lipid concentrations were determined. A total of 11 patients with homozygous familial hypercholesterolaemia were enrolled in this study. Lipid concentrations were measured, and the mean coronary flow velocity reserve was 1.97 plus or minus 0.51. Seven children were included in the group of patients with heterozygous familial hypercholesterolaemia. In these children, the mean coronary flow velocity reserve was 3.08 plus or minus 0.84. The coronary flow velocity reserve of homozygous familial hypercholesterolaemic patients is lower than that of heterozygous familial hypercholesterolaemic patients, and it is associated with a high concentration of low-density lipoprotein cholesterol. Aortic stenosis and plaques compromised the ostia of the coronary artery and caused increased basal mean diastolic coronary velocity with blunted increase in peak velocity, which decreased the coronary flow velocity reserve.

Improved Parameterization of the Transcranial Doppler Signal

The great potential of transcranial Doppler (TCD) as a tool for neuromonitoring is limited by the current parameterization of the signal. This article proposes a set of new parameters that more accurately represents the shape of the waveform and eliminates a number of confounding factors. This set of parameters was tested in 227 patients with ipsilateral carotid artery stenosis and compared with 31 normal subjects recruited at our laboratory. From the TCD waveform, we calculated on a beat-to-beat basis the maximal change in flow velocity at stroke onset (acceleration or acc), the maximal flow velocity during the first 100 ms of systole (sys1) and the maximal flow velocity in the remaining part of systole (sys2). All data were normalized relative to the mean diastolic flow velocity over an interval ranging from 520 till 600 ms after stroke onset (dias@560). For the group with carotid stenosis compared with the normal controls the average ± SD for acc (20.2 ± 9.5 vs. 20.2 ± 6.7; p = 0.98) and sys1 (1.82 ± 0.38 vs. 1.77 ± 0.56; p = 0.35) did not differ significantly. The average ±SD for sys2 (1.94 ± 0.33 vs. 1.50 ± 0.12; p < 0.001), however, was significantly higher in the group with carotid stenosis than in the group of normal subjects. The difference between sys1 and sys2 (“sys1–sys2”) was lower in the patient group than in controls (−0.12 ± 0.16 vs. 0.27 ± 0.22; p < 0.001). For the acc, there was a significantly higher variance in the group with stenosis than without (p < 0.001). Of the old parameters, the beat-to-beat mean (37.0 ± 13.1 vs. 41.3 ± 15.9; p = 0.17) and the pulsatility index (PI; 1.00 ± 0.26 vs. 0.91 ± 0.23; p = 0.06) were not significantly different between groups. Graphed together the acc and “sys1–sys2” parameters allowed a clear demarcation of both groups whereas in a graph of the old parameters mean and PI both groups overlapped considerably. In conclusion, the proposed set of new parameters not only has theoretical and practical benefits but also has excellent discriminative power in a group of carotid patients compared with normal controls.

Transesophageal Doppler Measurement of Renal Arterial Blood Flow Velocities and Indices in Children

Doppler-derived renal blood flow indices have been used to assess renal pathologies. However, transesophageal ultrasonography (TEE) has not been previously used to assess these renal variables in pediatric patients. In this study, we (a) assessed whether TEE allows adequate visualization of the renal parenchyma and renal artery, and (b) evaluated the concordance of TEE Doppler-derived renal blood flow measurements/indices compared with a standard transabdominal renal ultrasound (TAU) in children. This prospective cohort study enrolled 28 healthy children between the ages of 1 and 17 years without known renal dysfunction who were undergoing atrial septal defect device closure in the cardiac catheterization laboratory. TEE was used to obtain Doppler renal artery blood velocities (peak systolic velocity, end-diastolic velocity, mean diastolic velocity, resistive index, and pulsatility index), and these values were compared with measurements obtained by TAU. Concordance correlation coefficient (CCC) was used to determine clinically significant agreement between the 2 methods. The Bland-Altman plots were used to determine whether these 2 methods agree sufficiently to be used interchangeably. Statistical significance was accepted at P ≤ 0.05. Obtaining 2-dimensional images of kidney parenchyma and Doppler-derived measurements using TEE in children is feasible. There was statistically significant agreement between the 2 methods for all measurements. The CCC between the 2 imaging techniques was 0.91 for the pulsatility index and 0.66 for the resistive index. These coefficients were sensitive to outliers. When the highest and lowest data points were removed from the analysis, the CCC between the 2 imaging techniques was 0.62 for the pulsatility index and 0.50 for the resistive index. The 95% confidence interval (CI) for pulsatility index was 0.35 to 0.98 and for resistive index was 0.21 to 0.89. The Bland-Altman plots indicate good agreement between the 2 methods; for the pulsatility index, the limits of agreement were -0.80 to 0.53. The correlation of the size of the measurement and the mean difference in methods (-0.14; 95% CI = -0.28, 0.01) was not statistically significant (r = 0.31, P = 0.17). For the resistive index, the limits of agreement were -0.22 to 0.12. The correlation of the size of the measurement and the mean difference in methods (-0.05; 95% CI = -0.09, -0.01) was not statistically significant (r = 0.10, P = 0.65). This study confirms the feasibility of obtaining 2-dimensional images of kidney parenchyma and Doppler-derived measurements using TEE in children. Angle-independent TEE Doppler-derived indices show significant concordance with those derived by TAU. Further studies are required to assess whether this correlation holds true in the presence of renal pathology. This technique has the potential to help modulate intraoperative interventions based on their impact on renal variables and may prove helpful in the perioperative period for children at risk of acute kidney injury.

Longitudinal Left Ventricular Function in Normotensive Prediabetics: A Tissue Doppler and Strain/Strain Rate Echocardiography Study

Although diabetes mellitus is well known to result in systolic and diastolic left ventricular (LV) dysfunction at the subclinical level, even when it is not accompanied by hypertension and coronary artery disease, this situation has not been sufficiently investigated in prediabetes, which is the precursor of diabetes. The aims of the present study were to investigate LV systolic and diastolic function in normotensive and low-risk prediabetic and diabetic subjects for coronary disease using sensitive tissue Doppler echocardiographic parameters, to investigate early possible negative effects of glucose metabolism impairment on LV longitudinal function. Two hundred subjects (92 with prediabetes, 48 with type 2 diabetes, and 60 age-matched healthy volunteers) were studied by conventional, tissue Doppler, and strain and strain rate echocardiography. All study subjects were normotensive, and coronary artery disease was excluded. Forty-eight patients had isolated fasting glucose impairment, and 44 patients had combined fasting glucose and glucose tolerance impairment. Longitudinal peak systolic strain and the peak systolic and diastolic strain rates of six walls in the apical four-chamber, long-axis, and two-chamber views were evaluated. Clinical and standard echocardiographic characteristics were comparable among all groups. Mean systolic (P= .01) and diastolic (P= .02) tissue velocities, mean strain (P= .004), and mean systolic (P=.002) and diastolic (P= .001) strain rates were significantly lower in the diabetic groups than in control subjects. There were no difference between patients with isolated fasting glucose impairment and controls for tissue Doppler parameters, but mean early diastolic tissue velocity and mean strain and strain rates were statistically lower in patients with combined fasting glucose and glucose tolerance impairment compared with controls (P < .05). LV longitudinal systolic and diastolic function was impaired in both normotensive diabetic and prediabetic patients.

Abstract 8796: Comparison of Coronary Flow Velocity Reserve Measurement by Transthoracic Doppler Echocardiography with 320-Row Multidetector Computed Tomography Coronary Angiography for Predicting Coronary Artery Stenosis in Calcified Lesions in the Three Major Coronary Arteries

Objectives: This study examined the diagnostic accuracy of coronary flow velocity reserve (CFR) measurement using transthoracic Doppler echocardiography (TTDE) by comparing 320-row multidetector computed tomography coronary angiography (CTCA) for predicting coronary artery stenosis in calcified lesions in the 3 major coronary arteries. Methods and Results: Invasive coronary angiography (ICA), CTCA, and CFR measurement were performed in 101 patients. The presence of stenosis ≥50% was considered significant stenosis by ICA. By CTCA, the degree of coronary artery calcification was assessed using the Agatston calcium score (CS) method. Prospectively electrocardiographically-gated CTCA was performed with the use of test-injection method for the assessment of coronary artery stenosis. Coronary flow velocity was recorded in each target coronary artery by TTDE at rest and during hyperemia induced by intravenous infusion of adenosine triphosphate. CFR &lt;2, calculated as the ratio of hyperemic to basal peak and mean diastolic velocity, was considered ≥50% stenosis. Results: A significant coronary stenosis by ICA was found in 60 vessels. Coronary artery legions were successfully assessed in 91% and 95% of all vessels by CTCA and TTDE, respectively. CTCA had a sensitivity of 92%, a specificity of 93%, a positive predictive value (PPV) of 73%, and a negative predictive value (NPV) of 98% in patients with 0-299 CS, and had a sensitivity of 89%, a specificity of 67%, a PPV of 47%, and an NPV of 95% in patients with 300-599 CS for predicting coronary artery stenosis. In patients with ≥ 600 CS, 73% of vessels were unassessable. CFR&lt;2.0 had a sensitivity of 90%, a specificity of 90%, a PPV of 71%, and an NPV of 97% in patients with 0-299 CS, had a sensitivity of 92%, a specificity of 89%, a PPV of 79%, and an NPV of 96% in patients with 300-599 CS, and had a sensitivity of 100%, a specificity of 85%, a PPV of 77%, and an NPV of 100 % in patients with ≥ 600 CS for predicting coronary artery stenosis. Conclusions: CFR measurement accurately predicts significant coronary artery stenosis irrespectively of the degree of coronary artery calcification whereas progression of coronary calcification negatively influences diagnostic accuracy of CTCA-based assessment of coronary artery stenosis.

Reversal of fetal ductal constriction after maternal restriction of polyphenol-rich foods: an open clinical trial

To test the hypothesis that maternal restriction of polyphenol-rich foods (PRF), which, like non-steroidal anti-inflammatory drugs (NSAID), inhibit prostaglandin synthesis in the third trimester, reverse fetal ductal constriction (DC). An open clinical trial of 51 third trimester fetuses with DC with no history of NSAID intake was designed. All mothers were submitted to a food frequency questionnaire and were oriented to withdrawl PRF, being reassessed after 3 weeks. Doppler parameters were assessed before and after discontinuation of these substances. A control group of 26 third trimester normal fetuses, with no ductus arteriosus (DA) constriction, in which no dietary intervention was offered, was reviewed after 3 weeks. Student's t-test and Wilcoxon's test were used. Mean gestational age was 32±3 weeks (28 to 37 weeks). After discontinuation of PRF (≥3 weeks), 48/51 fetuses (96%) showed complete reversal of DC, with decrease in mean ductal systolic velocity (1.74±0.20 m s(-1) to 1.31±0.34 m s(-1), P<0.001), mean diastolic velocity (0.33±0.09 m s(-1) to 0.21±0.07 m s(-1), P<0.001) and mean right to left ventricular dimension ratio (1.37±0.26 to 1.12±0.17, P<0.001) and increase in mean ductal pulsatility index (PI) (1.98±0.36 to 2.46±0.23, P<0.001). Median daily maternal consumption of PRF was 286 mg per day and decreased after orientation to 0 mg per day, P<0.001. In the control group, with GA of 32±4 w (29-37 w), there was no significant differences in median daily maternal consumption of PRF, mean ductal systolic velocitiy, diastolic velocity, PI and right ventricular to left ventricular diameter ratio (RV/LV) ratio. Reduction of maternal PRF intake during pregnancy, especially in the third trimester, is followed by complete reversal of DC (wide open DA), which may influence maternal dietary habits in late pregnancy.

Effects of a Patent Ductus Arteriosus on Postprandial Intestinal Blood Flow in Extremely Low Birth Weight (ELBW) Neonates

Background: Patent ductus arteriosus (PDA) affects superior mesenteric artery blood flow velocity (SMA BFV) in fasting neonates. Recently, it has been reported that PDA affects postprandial mesenteric perfusion in premature baboons; however, the effects of PDA on postprandial mesenteric perfusion in preterm neonates have not been evaluated. Aims: To determine whether PDA affects postprandial SMA BFV in ELBW neonates. Methods: Appropriate for gestational age, ELBW preterm neonates, tolerating bolus enteral feedings were enrolled in this prospective observational study. Pulsed Doppler was used to measure preprandial and postprandial (at 30-min and 60-min) time-averaged mean, peak and end diastolic velocities (TAMV, PSV, EDV) once during the day of life 5 to 7; at the same time, PDA size was estimated using the PDA:left pulmonary artery (LPA) ratio : 0.5 (i.e., moderate/large PDA) and < 0.5 (i.e., small/no PDA). Mean values across time were graphed to illustrate relative changes in moderate/large and no/small PDA groups. Repeated measures ANOVA was used to compare SMA BFV changes between the groups from preprandial to 30-min and 60-min postprandial for each type of measured velocity (TAMV, PSV, EDV). Results: Of the38 infants studied, 16 were in the no/small PDA group; 22 were in the moderate/large PDA group. Postprandial TAMV, PSV and EDV were not different between these two groups ( p values were 0.798, 0.315 and 0.59, respectively). Conclusions: Changes in postprandial mesenteric blood velocity did not differ between infants with no/small PDA versus moderate/large PDA in this study's cohort of 38 ELBW neonates.

Color Doppler imaging of the ophthalmic artery in patients with chronic heart failure

To evaluate the ophthalmic artery hemodynamics in patients with chronic heart failure. Doppler parameters of ophthalmic artery of 18 patients with chronic heart failure in different stages of the disease were compared with 21 healthy volunteers (control group). These parameters were also correlated with echocardiographic assessments and clinical cardiologic status. Mean diastolic velocity was 5.14 ± 2.4 cm/s in the chronic heart failure group and 7.44 ± 3.5 cm/s in the control group (p=0.007). Mean resistance index of the ophthalmic artery was 0.76 ± 0.08 in the chronic heart failure group and 0.70 ± 0.08 in the control group (p=0.04). Mean systolic velocity of the ophthalmic artery was 22.03 ± 7.7 cm/s in the chronic heart failure group and 25.32 ± 9.2 cm/s in the control group (p=0.24). There was a negative correlation between the resistance index of the ophthalmic artery and systemic blood pressure of patients with chronic heart failure (r= -0.47, p=0.007). Diastolic velocity of the ophthalmic artery correlated positively with systemic blood pressure (r=0.44, p=0.02). Lower diastolic velocity and higher resistance index were observed in the ophthalmic artery of chronic heart failure patients when compared to the control group, which probably reflects the presence of orbital vasoconstriction in response to low cardiac output. Therefore, the influence of these findings on the structure and function of the optic nerve head deserves investigation.

Comparison of Coronary Microcirculation in Female Nurses After Day-Time Versus Night-Time Shifts

Nightshift work, which is known to cause mental stress and disrupt normal biological diurnal rhythms, leads to endothelial dysfunction resulting in increased risk for cardiovascular disease. This study aimed to investigate the acute effect of night-shift work on coronary microcirculation through assessment of coronary flow reserve (CFR) by transthoracic Doppler echocardiography. This study consisted of 36 women nurses who underwent transthoracic Doppler echocardiographic examinations after working a nightshift and on a regular day without previous nightshift work. Flow velocity in the distal portion of the left anterior descending coronary artery was measured at baseline and during adenosine infusion. CFR was calculated as the ratio of hyperemic to basal mean diastolic flow velocity. CFR after night work was lower than that on a regular workday (3.8 ± 0.6 vs 4.1 ± 0.6, p <0.001). Degree of decreases in CFR after night work was correlated to Framingham risk score (r = 0.35, p = 0.036). In conclusion, this study demonstrated that coronary microcirculation was impaired after nightshift work in women nurses.

Assessment of Coronary Flow Velocity Reserve by Transthoracic Doppler Echocardiography Before and After Coronary Artery Bypass Grafting

Little is known about the changes in the coronary flow velocity reserve (CFVR) of the left anterior descending artery (LAD) before and after coronary artery bypass grafting (CABG). The present study aimed to evaluate the feasibility of measuring the CFVR of the LAD using transthoracic Doppler echocardiography before and after CABG. We prospectively measured the CFVR before and after CABG in 56 patients. The flow velocity in the LAD was measured using transthoracic Doppler echocardiography both at rest and during intravenous infusion of adenosine. The CFVR was calculated as the ratio of hyperemic to the basal peak and mean diastolic flow velocities. Coronary angiography was also performed to assess graft patency after CABG in all patients. Furthermore, we compared the differences between the pre- and postoperative CFVR in patients with and without a diffusely diseased LAD (lesion length >2 cm). All grafts were angiographically patent. The postoperative peak and mean CFVR were significantly increased compared to the preoperative peak and mean CFVR (both peak and mean 2.7 ± 0.9 vs 1.5 ± 0.6, respectively; p<0.0001). The preoperative peak CFVR was significantly lower in patients with a diffusely diseased LAD than in those without a diffusely diseased LAD (1.3 ± 0.5 vs 1.6 ± 0.5, respectively; p=0.04). The postoperative peak CFVR of the 2 groups was almost identical (2.5 ± 0.6 vs 2.9 ± 1.0; p=0.07). In conclusion, assessment of the CFVR of the LAD using transthoracic Doppler echocardiography was useful after CABG for confirming graft patency.

Impaired coronary flow reserve in obstructive sleep apnea and its improvement after continuous positive airway pressure therapy: a transthoracic Doppler echocardiographic study.

It is reported that patients with obstructive sleep apnea syndrome (OSAS) show endothelial dysfunction and that treatment of OSAS by continuous positive airway pressure (CPAP) therapy improves it. In this study we evaluated coronary flow reserve (CFR), which is considered to be affected by coronary microvascular dysfunction, and the change in CFR during treatment of OSAS by CPAP. Eleven patients who were diagnosed as having OSAS by polysomnography (PSG) were studied. Phasic coronary flow velocity was obtained in the left anterior descending coronary artery at baseline and during hyperemic conditions with transthoracic 2D echocardiography. CFR was defined as the ratio of hyperemic to basal mean diastolic velocity. CFR was obtained before and after the initiation of CPAP therapy. Coronary flow reserve was decreased (<2.5) in 8 of 11 (73%) patients at baseline. After CPAP therapy, CFR of these 8 patients increased significantly. Coronary flow reserve was decreased in 73% of the patients with OSAS and was significantly improved after CPAP therapy.

363 Probiotics Supplementation Increases Intestinal Blood Flow in Extremely Low Birth Weight (ELBW) Neonates

Background: Proposed benefits of probiotics supplementation are multiple; recently, vasoactive properties of trace amines, produced by probiotics, have been shown to affect mesenteric vasculature in animal models. The effects of probiotics on intestinal blood flow have not yet been described. Aims: To determine whether probiotics supplementation affects intestinal blood flow velocity in ELBW neonates. Methods: In this randomized, double-blind, placebo-controlled study probiotics (500 M CFU of Lactobacillus rhamnosus and 500 million CFU of Bifidobacterium infantis) were added to the first enteral feeding and continued until discharge or 34 weeks postmenstrual age. Pulsed Doppler measured preprandial and postprandial (at 30 and 60 min) time-averaged mean, peak and end diastolic velocities (TAMV, PSV, EDV) during second week of life after 7 days of probiotics supplementation. Mean values across time were graphed for probiotics and control groups. The percent change from preprandial to 60 min post was compared by t-test, for each measurement method. Results: Thirty-one infants were studied, 15 randomized to probiotics and 16 to placebo. Postprandial TAMV were increased significantly in probiotics group (p = 0.048), with PSV and EDV showing a trend. There were no significant differences between groups in mean birth weight, gestational age, the time of the study, volume and type of feedings (p > 0.05). The percent of infants undergoing phototherapy, receiving caffeine or being diagnosed with patent ductus arteriosus was similar between groups (p > 0.05). Conclusions: Probiotics administration significantly increases intestinal blood flow in ELBW preterm neonates when compared to placebo group.

Impaired endothelial progenitor cell recruitment may contribute to heart transplant microvasculopathy

Circulating progenitor cells (PCs) may play a role in the pathogenesis of cardiac allograft vasculopathy, the leading cause of morbidity and mortality in heart transplantation (HTx). We assessed the relationship between circulating PCs and their incorporation into allografts and coronary microvascular function in HTx. PCs were quantified by flow cytometry on the basis of the surface expression of CD34, CD133, and kinase domain receptor (KDR) antigens. Biopsy specimens at 2 different times were examined. Immunohistochemistry for the stem cell marker c-Kit, endothelial PC (EPC) marker KDR, and CD34 was performed in serial sections in all specimens. Cells positive for each marker were counted in all specimen area sections, and the number obtained was corrected by area section. Coronary flow in the left anterior descending coronary artery was detected at rest and during intravenous adenosine by transthoracic echocardiography. Coronary flow reserve (CFR) was the ratio of hyperemic diastolic mean velocity (DMV)/resting DMV. CFR was measured in 29 patients and was abnormal (CFR < 2) in 6 (Group A) and normal in 23 (Group B). CFR was lower in Group A (1.5 ± 0.1 vs 3.3 ± 0.8, p < 0.0001). CD34(+)KDR(+), CD133(+)KDR(+), and CD34(+)CD133(+)KDR(+) cell counts were lower in Group A (p < 0.05). EPCs in biopsy sections tended to be lower in Group A (p = 0.06) and correlated to circulating CD133(+)KDR(+) and CD34(+)CD133(+)KDR(+) (p = 0.003 and p = 0.052, respectively). EPCs are decreased in the circulation and in the allograft in patients with microvasculopathy. Defective mobilization and engraftment of EPCs may be involved in the pathogenesis of cardiac allograft vasculopathy.

Metformin is associated with improved left ventricular diastolic function measured by tissue Doppler imaging in patients with diabetes

To examine the association between selected glucose-lowering medications and left ventricular (LV) diastolic function in patients with diabetes. Retrospective cohort study (years 2005-2008). Echocardiograms of 242 patients with diabetes undergoing coronary angiography were analyzed. All patients had an LV ejection fraction (LVEF) ≥20% and were without atrial fibrillation, bundle branch block, valvular disease, or cardiac pacemaker. Patients were grouped according to the use of metformin (n=56), sulfonylureas (n=43), insulin (n=61), and combination treatment (n=82). Mean age (66±10 years) and mean LVEF (45±11%) were similar across the groups. Mean isovolumic relaxation time (IVRT) was 66±31, 79±42, 69±23, and 66±29 ms in metformin, sulfonylureas, insulin, and combination treatment groups respectively (P=0.4). Mean early diastolic longitudinal tissue velocity (e') was 5.3±1.6, 4.6±1.6, 5.3±1.8, and 5.4±1.7 cm/s in metformin, sulfonylureas, insulin, and combination treatment groups (P=0.04). In adjusted linear regression models, the use of metformin was associated with a shorter IVRT (parameter estimate -9.9 ms, P=0.049) and higher e' (parameter estimate +0.52 cm/s, P=0.03), compared with no use of metformin. The effects of metformin were not altered by concomitant use of sulfonylureas or insulin (P for interactions >0.4). The use of metformin is associated with improved LV relaxation, as compared with no use of metformin.

Evaluation of early and late postoperative flow capacity of internal thoracic artery bypass by means of stress Doppler echocardiography

Arterial revascularization with the internal thoracic artery (ITA) has shown exceptional long-term results, even though early hypoperfusion can occur and can cause ischemia and contractile dysfunction. Therefore, it is still controversial as to whether the bypass vessel can guarantee the required demand for blood flow during the early postoperative (EPO) phase or whether this is only possible a long time after the operation. This question is important particular in the early postoperative phase to manage afterload and reduce left ventricular oxygen demand. Therefore, stress Doppler echocardiography was performed to assess EPO and late postoperative (LPO) flow capacity after minimal-invasive coronary artery bypass grafting (MIDCAB) in subjects with single vessel disease. Doppler echocardiography was performed after MIDCAB in 15 patients (mean age 65 years+/-12 standard deviation) in the EPO (15 days) and LPO (266 days) at rest and under stress. The mean diastolic velocity (MDV) as a measure for the coronary perfusion in the bypass-graft was comparable (30.9+/-14.5 EPO to 30.8+/-13.9 cm/s LPO, P>0.05) for both settings (early vs. late). In both tests, the stress reactions by means of handgrip maneuver lead to comparable increases in blood flow: MDV 65.0+/-54.4% (EPO) to 62.5+/-53.7% n.s. (LPO). The flow increase in the bypass graft was just as similar [48.2+/-46.2% (EPO) to 51.1+/-41.6% n.s. (LPO)]. The stress echocardiography revealed for the first time that the ITA-graft after MIDCAB-operation is able to produce the same flow reserve through the EPO phase as well as the LPO phase. Restrictions to a maximum early flow adaptation are not justified. Thus, particularly a patient with severe comorbidities or higher age should be mobilized in the EPO phase to minimize the postoperative complications without risk of myocardial ischemia caused by impaired early blood flow through recent implanted ITA. This method for assessment of ITA blood flow allows for long-time observations and can detect disturbances in perfusion at an early stage.

Estimation of Coronary Flow Velocity Reserve Using Transthoracic Doppler Echocardiography and Cold Pressor Test Might Be Useful for Detecting of Patients with Variant Angina

The cold pressor test (CPT) has been used to detect variant angina, but its sensitivity in predicting vasospasm is low. The aim of this study was to determine whether estimates of the coronary flow velocity reserve (CFVR) in the distal left anterior descending coronary artery (dLAD) using transthoracic echocardiography (TTE) and CPT are useful tool to predict variant angina. 65 patients (mean age = 52 +/- 10 years; male:female = 41:24) who had normal coronary artery on angiography and underwent acetylcholine provocation test were enrolled and divided into the spasm group (n = 31) and the no spasm group (n = 34). During CPT, the peak (PDV) and mean diastolic flow velocity (MDV) of the dLAD were estimated using TTE with a high-frequency transducer, and electrocardiography, blood pressures, heart rate, and symptoms were monitored every 30 seconds. CPT%PDV and CPT%MDV were defined as the percentage changes in PDV and MDV during CPT, respectively. CPT%PDV was 4.99 +/- 23.62% in the spasm group and 52.75 +/- 24.78% in the no spasm group (P < 0.001). CPT%MDV was 6.83 +/- 23.81% in the spasm group and 50.22 +/- 27.83% in the no spasm group (P < 0.001). CPT%PDV<31.1% had a sensitivity of 93.5% and a specificity of 82.4% in predicting variant angina (95% confidence interval [CI]: 0.939-0.979, P < 0.001). CPT%MDV<30.55% had a sensitivity of 90% and a specificity of 76.5% in predicting variant angina (95% CI: 0.884-0.950, P < 0.001). The measurement of changes in the coronary flow velocity of the dLAD using TTE and CPT might be useful for the estimation of endothelial dysfunction in patients with variant angina.

Effects of alagebrium, an advanced glycation end‐product breaker, in patients with chronic heart failure: study design and baseline characteristics of the BENEFICIAL trial

Previous small open label studies have shown that the advanced glycation end-product (AGE) breaker alagebrium may improve cardiac function in patients with chronic heart failure (HF). We report the design, methods and baseline characteristics of a double-blind, placebo-controlled, randomized trial evaluating the efficacy and safety of alagebrium (BENEFICIAL) in patients with HF and a left ventricular ejection fraction (LVEF) <or= 0.45. Patients with NYHA II-IV stable HF for at least 3 months were eligible for this study. One hundred and two patients were included in the study and randomized to either 200 mg alagebrium twice daily or placebo for a period of 36 weeks. The mean age of patients was 60 +/- 11 years, 78% were male, and 17% were diabetic. Mean peak VO(2) was 21.7 +/- 5.9 mL/min/kg, mean LVEF was 0.32 +/- 0.09. Diastolic function was worse (mean early tissue diastolic velocity (E') 4.6 +/- 1.7 vs. 6.1 +/- 2.0 cm/s; P < 0.001) in patients with LVEF <or= 0.35 compared to patients with LVEF between 0.35 and 0.45. The BENEFICIAL study is a proof-of-concept study that will provide new data on the efficacy and safety of the AGE crosslink breaker alagebrium in systolic HF patients. EudraCT number of this trial is NCT00516646.

Incremental Prognostic Value of Novel Left Ventricular Diastolic Indexes for Prediction of Clinical Outcome in Patients With ST-Elevation Myocardial Infarction

This study examined the prognostic value of novel diastolic indexes in ST-elevation acute myocardial infarction (AMI), derived from strain and strain rate analysis using 2-dimensional speckle tracking imaging. Echocardiograms were obtained within 48 hours of admission in 371 consecutive patients with first ST-elevation AMI (59.7 +/- 11.6 years old). Indexes of diastolic function including mean strain rate during isovolumic relaxation (SR(IVR)), mean early diastolic strain rate (SR(E)) and mean diastolic strain at peak transmitral E wave (E) were obtained from 3 apical views. Mean early diastolic velocity from 4 basal segments by color-coded tissue Doppler imaging was measured. Indexes of diastolic filling including E/SR(IVR), E/SR(E), E/diastolic strain at E, and E/early diastolic velocity were calculated. The primary end point (composite of death, hospitalization for heart failure, repeat MI, and repeat revascularization) occurred in 84 patients (22.6%) during a mean follow-up of 17.3 +/- 12.2 months. Mean SR(IVR) (p <0.001), multivessel disease (p <0.001), Thrombolysis In Myocardial Infarction grade 0 to 1 flow after percutaneous coronary intervention (p = 0.004), and left ventricular ejection fraction (p = 0.008) were independent predictors of the combined end point on Cox regression analysis. Mean SR(IVR) showed incremental prognostic value over baseline clinical and echocardiographic variables (global chi-square increase from 41.0 to 51.6, p <0.001). After dividing patient population based on median SR(IVR), patients with SR(IVR) < or =0.24/second had significantly higher event rates than others (hazard ratio 2.74, 95% confidence interval 1.61 to 4.67, p <0.001). In conclusion, SR(IVR) was incremental to left ventricular ejection fraction, Thrombolysis In Myocardial Infarction grade 0 to 1 flow after percutaneous coronary intervention, and multivessel disease and superior to other diastolic indexes in predicting future cardiovascular events after AMI. SR(IVR) may be useful in identifying high-risk patients soon after AMI.