Age-independent myocardial infarct quantification by signal intensity percent infarct mapping in swine.

PURPOSE: To test whether signal intensity percent infarct mapping (SI-PIM) accurately determines the size of myocardial infarct (MI) regardless of infarct age. MATERIALS AND METHODS: Forty-five swine with reperfused MI underwent 1.5T late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) after bolus injection of 0.2 mmol/kg Gd(DTPA) on days 2-62 following MI. Animals were classified into acute, healing, and healed groups by pathology. Infarct volume (IV) and infarct fraction (IF) were determined by two readers, using binary techniques (including 2-5 standard deviations [SD] above the remote, and full-width at half-maximum) and the SI-PIM method. Triphenyl-tetrazolium-chloride staining (TTC) was performed as reference. Bias (percent under/overestimation of IV relative to TTC) of each quantification method was calculated. Bland-Altman analysis was done to test the accuracy of the quantification methods, while intraclass correlation coefficient (ICC) analysis was done to assess intra- and interobserver agreement. RESULTS: Bias of the MRI quantification methods do not depend on the age of the MI. Full-width at half-maximum (FWHM) and SI-PIM gave the best estimate of MI volume determined by the reference TTC (P-values for the FWHM and SI-PIM methods were 0.183, 0.26, 0.95, and 0.073, 0.091, 0.73 in Group 1, Group 2, and Group 3, respectively), while using any of the binary thresholds of 2-4 SDs above the remote myocardium showed significant overestimation. The 5 SD method, however, provided similar IV compared to TTC and was shown to be independent of the size and age of MI. ICC analysis showed excellent inter- and intraobserver agreement between the readers. CONCLUSION: Our results indicate that the SI-PIM method can accurately determine MI volume regardless of the pathological stage of MI. Once tested, it may prove to be useful for the clinic.

[Asymmetric dimethylarginine: predictor of cardiovascular diseases?]. / Aszimmetrikus dimetilarginin: a cardiovascularis betegségek prediktora?

Cardiovascular diseases are the most common diseases worldwide. They are responsible for one third of global deaths and they are the leading cause of disability, too. The usage of different levels of prevention in combination with effective risk assessment improved these statistical data. Risk assessment based on classic risk factors has recently been supported with several new markers, such as asymmetric dimethylarginine, which is an endogenous competitive inhibitor of nitric oxide synthase. Elevated levels of asymmetric dimethylarginine have been reported in obese, smoker, hypercholesterolemic, hypertensive and diabetic patients. According to previous studies, asymmetric dimethylarginine is a suitable indicator of endothelial dysfunction, which is held to be the preceding condition before atherosclerosis. Several researches found positive correlation between higher levels of asymmetric dimethylarginine and coronary artery disease onset, or progression of existing coronary disease. According to a study involving 3000 patients, asymmetric dimethylarginine is an independent risk factor of cardiovascular mortality in patients with coronary artery disease. This article summarizes the role of asymmetric dimethylarginine in prediction of cardiovascular diseases, and underlines its importance in cardiovascular prevention.

The effect of physical exercise on arterial stiffness parameters in young sportsmen.

OBJECTIVE: This study aimed to determine the effect of single-bout exercise on aortic stiffness parameters in young basketball players. METHOD AND RESULTS: A total of 108 young male subjects (mean age 14.2 ± 3.4 years) were enrolled into the study. Simultaneous measure- ment of aortic pulse wave velocity (PWVao) and augmentation index (Alxao) were performed with the oscillometric, occlusive device. Echocardiographic parameters of left ventricular systolic and diastolic function at rest were also measured in sportsmen. We did not find significant differences of resting PWVao in comparison with young sportsmen (S) and age-matched healthy volunteers (V): 5.82 ± 0.14 m/s vs 5.83 ± 0.12 m/s for S and V groups, respectively. The values of PWVao measured after dynamic exercise, isometric exercise, and rest were 8.0 ± 0.5 m/s, 5.86 ± 0.1 m/s and 5.82 ± 0.1 m/s, respectively. We confirmed that values after dynamic exercise are significantly different from those after isometric exercise (P < 0.01) and those after rest (P < 0.01). The Alxao values exhibited a considerable, but statistically non-significant, decrease during dynamic exercise in the three groups (11.7 ± 7% vs 3.8 ± 3% vs- 0.9 ± 0.9% for groups 1, 2, and 3, respectively). CONCLUSION: We applied a feasible, clinically useful method which allowed us to measure changes in aortic PWV and Alx during acute, single-bout exercise on the basketball court in young sportsmen.

Diagnosis rates, therapeutic characteristics, lifestyle, and cancer screening habits of patients with diabetes mellitus in a highly deprived region in Hungary: a cross-sectional analysis.

Introduction: Low socioeconomic status affects not only diagnosis rates and therapy of patients with diabetes mellitus but also their health behavior. Our primary goal was to examine diagnosis rates and therapy of individuals with diabetes living in Ormánság, one of the most deprived areas in Hungary and Europe. Our secondary goal was to examine the differences in lifestyle factors and cancer screening participation of patients with diagnosed and undiagnosed diabetes compared to healthy participants. Methods: Our study is a cross-sectional analysis using data from the "Ormánság Health Program". The "Ormánság Health Program" was launched to improve the health of individuals in a deprived region of Hungary. Participants in the program were coded as diagnosed diabetes based on diagnosis by a physician as a part of the program, self-reported diabetes status, and self-reported prescription of antidiabetic medication. Undiagnosed diabetes was defined as elevated blood glucose levels without self-reported diabetes and antidiabetic prescription. Diagnosis and therapeutic characteristics were presented descriptively. To examine lifestyle factors and screening participation, patients with diagnosed and undiagnosed diabetes were compared to healthy participants using linear regression or multinomial logistic regression models adjusted for sex and age. Results: Our study population consisted of 246 individuals, and 17.9% had either diagnosed (n=33) or undiagnosed (n=11) diabetes. Metformin was prescribed in 75.8% (n=25) of diagnosed cases and sodium-glucose cotransporter-2 inhibitors (SGLT-2) in 12.1% (n=4) of diagnosed patients. After adjustment, participants with diagnosed diabetes had more comorbidities (adjusted [aOR]: 3.50, 95% confidence interval [95% CI]: 1.34-9.18, p<0.05), consumed vegetables more often (aOR: 2.49, 95% CI: 1.07-5.78, p<0.05), but desserts less often (aOR: 0.33, 95% CI: 0.15-0.75, p<0.01) than healthy individuals. Patients with undiagnosed diabetes were not different in this regard from healthy participants. No significant differences were observed for cancer screening participation between groups. Conclusions: To increase recognition of diabetes, targeted screening tests should be implemented in deprived regions, even among individuals without any comorbidities. Our study also indicates that diagnosis of diabetes is not only important for the timely initiation of therapy, but it can also motivate individuals in deprived areas to lead a healthier lifestyle.

The impact of cardiopulmonary manifestations on the mortality of SSc: a systematic review and meta-analysis of observational studies.

OBJECTIVES: Internal organ involvement reduces the life expectancy of SSc patients. Cardiopulmonary manifestations are currently the primary cause of death. We aimed to perform a systematic review and meta-analysis to define more precise effect estimates of different cardiopulmonary manifestations and to verify trends in the mortality of SSc. METHODS: A systematic literature search was performed to identify relevant cohort studies. Reports analyzing the role of the organ manifestations in mortality or analysing survival compared with the control population were included. The outcome parameters were pooled with the random-effect model via generic inverse-variance weighting in conventional and cumulative meta-analysis. RESULTS: Eighteen studies comprising a total of 12, 829 patients qualified. The reported causes of death were as follows: 19.7% cardiac, 16.8% interstitial pulmonary disease, 13.1% pulmonary hypertension and 13.8% renal disease. The risk of death was significantly increased in patients with cardiac involvement [hazard ratio (HR) 3.15], with pulmonary interstitial disease (HR 2.58), with pulmonary hypertension (HR 3.50) and with renal manifestations (HR 2.76). A trend for survival improvement (R2)= 0.4295, P = 0.04) was found, and the difference in survival between the diffuse and limited scleroderma subgroups was diminishing (R2)= 0.4119. P = 0.02). CONCLUSION: Meta-analysis of observational studies indicates a trend for improvement over the last decades in which the life expectancy of SSc patients approaches that of the general population. A decreasing tendency in the survival differences between the limited and diffuse SSc subgroups was also verified. Internal organ involvements have similarly unfavourable predictive impact on survival.

Updated and revised normal values of aortic pulse wave velocity in children and adolescents aged 3-18 years.

Measurement of aortic pulse wave velocity (PWVao) is recommended for stratifying individual cardiovascular (CV) risk in adults. Diseases in children and adolescents might influence aortic stiffness. It is necessary to exclude overweight (OW), obese (O) subjects, and individuals with increased systolic (SBP) and/or diastolic blood pressure (DBP) from the population, when creating normal values of PWVao in children and adolescents. Body mass index (BMI), SBP/DBP cut-off values have remarkably changed in this population during the last decade. Aims of our study were to expand our previously published PWVao database and to revise it by using the recently determined normal values. PWVao was measured by an occlusive-oscillometric device (Arteriograph, TensioMed Ltd, Budapest, Hungary) in a healthy population aged 3-18 years. 7940 (4374 boys) participants were recruited, 1912 OW/O subjects and 1368 individuals with high SBP/DBP were excluded. Finally, n = 4690 (2599 boys) participants were enrolled. Mean PWVao values increased from 5.4 ± 0.6 to 6.4 ± 0.5 m/s (p < 0.05) in boys and from 5.5 ± 0.6 to 6.4 ± 0.5 m/s (p < 0.05) in girls. Mean PWVao values were significantly lower in our new study, in boys in age groups of 9-16, in girls in age groups of 11-17. This is the largest and widest age-ranged database of PWVao published to date. Due to the change of BMI and SBP/DBP reference values during the last decade, the "old" database of PWVao needed to be revised. As a result of this, normal values of PWVao decreased significantly in both sexes.

Low platelet disaggregation predicts poor response to 150 mg clopidogrel in patients with elevated platelet reactivity.

Raising the maintenance dose of clopidogrel to 150 mg enhances platelet inhibition (PI) in patients with elevated platelet reactivity (EPR); however, large differences were observed between individuals in the extent of this benefit. We aimed to find clinical and platelet function variables that might predict the response to 150 mg clopidogrel in patients with EPR. ADP 5 microM-stimulated peak aggregation (Agg(max)), 6-minute late aggregation (Agg(late)) and 6-minute disaggregation (disAgg) were measured with light transmission aggregometry (LTA) in a consecutive cohort of 202 patients admitted for emergent or elective percutaneous coronary intervention (PCI) after receiving a 600-mg loading dose of clopidogrel. PI was assessed 12 to 18 hours after loading dose and 30 days after the intervention. EPR was defined as a Agg(max) value greater than 34%. From the first day of PCI, 85 patients with EPR received 150 mg clopidogrel for 30 days, while others with normal platelet reactivity (NPR) took 75 mg clopidogrel. Baseline clinical and LTA variables were analyzed in multivariable regression models. Administration of 150 mg clopidogrel enhanced PI and decreased the prevalence of EPR at 30 days compared to the peri-interventional period (Agg(max): 46.9 +/- 8.3 vs. 37.3 +/- 11.5; EPR: 100% vs. 62.4%; p < 0.001 in both cases); however, the achieved level of platelet reactivity was higher than patients with NPR (Agg(max): 20.6 +/- 8.1 vs. 25.3 +/- 10.8, p < 0.001). Multivariable logistic regression revealed low platelet disaggregation (odds ratio (OR): 12.49; 95% CI: 2.52-62.00; P = 0.002) and acute coronary syndrome (OR: 4.83; 95% CI: 1.54-15.09; P = 0.008) as independent predictors of EPR. The area under the receiver-operating-characteristic curve was 0.72 +/- 0.06 for disaggregation to predict NPR after 150 mg clopidogrel. The optimal disaggregation cut-off was 16.5% with a sensitivity of 94% and a specificity of 43%. Administering 150 mg maintenance dose of clopidogrel enhanced antiplatelet potency; however, more than half of the patients persisted with EPR. Acute coronary syndrome and low (<16.5%) platelet disaggregation are independent predictors of poor benefit from dose shift.

L-Arginine-Nitric Oxide-Asymmetric Dimethylarginine Pathway and the Coronary Circulation: Translation of Basic Science Results to Clinical Practice.

By 1980, it was thought that we already knew most of the major mechanisms regulating vascular tone. However, after the somewhat serendipity discovery that endothelium is involved in mediation of relaxation to acetylcholine, a whole new world opened up and we had to rewrite our concept regarding vascular function and its regulation (not to mention many other fields). The new player was an endothelium derived relaxing factor, which molecular constitution has been identified to be nitric oxide (NO). This review summarizes the major molecular steps concerning how NO is synthetized from L-arginine. Also, the fate of L-arginine is described via the arginase and methylation pathways; both of them are affecting substantially the level and efficacy of NO. In vitro and in vivo effects of L-arginine are summarized and controversial clinical findings are discussed. On the basis of the use of methylated L-arginines, the vasomotor effects of endothelial NO released to agonists and increases in flow/wall shear stress (a major biological stimulus) is summarized. In this review the role of NO in the regulation of coronary vascular resistance, hence blood flow, is delineated and the somewhat questionable clinical use of NO donors is discussed. We made an attempt to summarize the biosynthesis, role, and molecular mechanisms of endogenously produced methylated L-arginine, asymmetric dimethylarginine (ADMA) in modulating vascular resistance, affecting the function of the heart. Additionally, the relationship between ADMA level and various cardiovascular diseases is described, such as atherosclerosis, coronary artery disease (CAD), ischemia/reperfusion injuries, and different types of coronary revascularization. A novel aspect of coronary vasomotor regulation is identified in which the pericardial fluid ADMA and endothelin play putative roles. Finally, some of the open possibilities for future research on L-arginine-NO-ADMA signaling are highlighted.

Oscillometrically Measured Aortic Pulse Wave Velocity Reveals Asymptomatic Carotid Atherosclerosis in a Middle-Aged, Apparently Healthy Population.

BACKGROUND: Asymptomatic atherosclerosis is a common entity even at young age. Studies have suggested a strong relationship between increased arterial stiffness and asymptomatic carotid atherosclerosis (ACA) in general population, particularly in those with high cardiovascular risk, but no data exist from a younger population free from recognized cardiovascular disease. Hypothesis. We hypothesized there is an association between ACA and aortic pulse wave velocity (PWVao) in middle-aged, apparently healthy, normotensive population to reveal increased cardiovascular risk. METHODS: We examined the relationship between ACA and PWVao in 236 apparently healthy, asymptomatic, normotensive, middle-aged subjects (age 47 ± 8 years; 52% women). PWVao was measured with the oscillometric method (Arteriograph). ACA was assessed by carotid artery ultrasonography. RESULTS: ACA was present in 51 subjects. Subjects with ACA were older (p < 0.009), more likely to be smokers (p < 0.009), more likely to be smokers (p < 0.009), more likely to be smokers (p < 0.009), more likely to be smokers (p < 0.009), more likely to be smokers (p < 0.009), more likely to be smokers (p < 0.009), more likely to be smokers (p < 0.009), more likely to be smokers (. CONCLUSIONS: PWVao measured by the Arteriograph proved to be an independent marker of ACA. Our study may reveal high CV risk, detected as increased PWVao, which according to our study is related in a very high probability to asymptomatic carotid atherosclerosis in apparently healthy, young, and middle-aged subjects.

The MRI characteristics of the no-flow region are similar in reperfused and non-reperfused myocardial infarcts: an MRI and histopathology study in swine.

BACKGROUND: The no-flow region (NF) visualised by magnetic resonance imaging (MRI) in myocardial infarction (MI) has been explained as the product of reperfusion-injury-induced microvascular obstruction. However, a similar MRI phenomenon occurs in non-reperfused MI. Accordingly, our purpose was to compare the MRI and histopathologic characteristics of the NF in reperfused and non-reperfused MIs. METHODS: Reperfused (n = 7) and non-reperfused MIs (n = 7) were generated in swine by percutaneous balloon occlusion and microsphere embolisation techniques. Four days post-MI, animals underwent myocardial T2-mapping, early and serial late gadolinium enhancement MRI. MI and NF were compared between the models using the independent samples t test. Serial measurements were analysed using repeated measures analysis of variance. Triphenyltetrazolium chloride (TTC) macroscopic and microscopic histopathologic assessment was also performed. RESULTS: The MI size in the reperfused and non-reperfused groups was 17.1 ± 3.4 ml and 19.4 ± 8.1 ml, respectively (p = 0.090), in agreement with TTC assessment (p = 0.216; p = 0.484), and the NF size was 7.7 ± 2.4 ml and 8.1 ± 1.9 ml, respectively (P = 0.211). Compared to the reference 2-min post-contrast measurement, the NF size was significantly reduced at 20 min in the reperfused group and at 25 min in the non-reperfused group (both p < 0.001). Nevertheless, the NF was still detectable at 45 min after injection. No significant T2 difference was observed between the groups (p > 0.326). Histopathologic assessment revealed extensive calcification and hemosiderin deposition in the NF of the reperfused MI, but not in the non-reperfused MI. CONCLUSIONS: The NF in non-reperfused and reperfused MIs have similar characteristics on MRI despite the different pathophysiologic and underlying histopathologic conditions, indicating that the presence of the NF alone cannot differentiate between these two types of MI.

In Vitro Longitudinal Relaxivity Profile of Gd(ABE-DTTA), an Investigational Magnetic Resonance Imaging Contrast Agent.

PURPOSE: MRI contrast agents (CA) whose contrast enhancement remains relatively high even at the higher end of the magnetic field strength range would be desirable. The purpose of this work was to demonstrate such a desired magnetic field dependency of the longitudinal relaxivity for an experimental MRI CA, Gd(ABE-DTTA). MATERIALS AND METHODS: The relaxivity of 0.5mM and 1mM Gd(ABE-DTTA) was measured by Nuclear Magnetic Relaxation Dispersion (NMRD) in the range of 0.0002 to 1T. Two MRI and five NMR instruments were used to cover the range between 1.5 to 20T. Parallel measurement of a Gd-DTPA sample was performed throughout as reference. All measurements were carried out at 37°C and pH 7.4. RESULTS: The relaxivity values of 0.5mM and 1mM Gd(ABE-DTTA) measured at 1.5, 3, and 7T, within the presently clinically relevant magnetic field range, were 15.3, 11.8, 12.4 s-1mM-1 and 18.1, 16.7, and 13.5 s-1mM-1, respectively. The control 4 mM Gd-DTPA relaxivities at the same magnetic fields were 3.6, 3.3, and 3.0 s-1mM-1, respectively. CONCLUSIONS: The longitudinal relaxivity of Gd(ABE-DTTA) measured within the presently clinically relevant field range is three to five times higher than that of most commercially available agents. Thus, Gd(ABE-DTTA) could be a practical choice at any field strength currently used in clinical imaging including those at the higher end.

Infarct density distribution by MRI in the porcine model of acute and chronic myocardial infarction as a potential method transferable to the clinic.

To study the feasibility of a myocardial infarct (MI) quantification method [signal intensity-based percent infarct mapping (SI-PIM)] that is able to evaluate not only the size, but also the density distribution of the MI. In 14 male swine, MI was generated by 90 min of closed-chest balloon occlusion followed by reperfusion. Seven (n = 7) or 56 (n = 7) days after reperfusion, Gd-DTPA-bolus and continuous-infusion enhanced late gadolinium enhancement (LGE) MRI, and R1-mapping were carried out and post mortem triphenyl-tetrazolium-chloride (TTC) staining was performed. MI was quantified using binary [2 or 5 standard deviation (SD)], SI-PIM and R1-PIM methods. Infarct fraction (IF), and infarct-involved voxel fraction (IIVF) were determined by each MRI method. Bias of each method was compared to the TTC technique. The accuracy of MI quantification did not depend on the method of contrast administration or the age of the MI. IFs obtained by either of the two PIM methods were statistically not different from the IFs derived from the TTC measurements at either MI age. IFs obtained from the binary 2SD method overestimated IF obtained from TTC. IIVF among the three different PIM methods did not vary, but with the binary methods the IIVF gradually decreased with increasing the threshold limit. The advantage of SI-PIM over the conventional binary method is the ability to represent not only IF but also the density distribution of the MI. Since the SI-PIM methods are based on a single LGE acquisition, the bolus-data-based SI-PIM method can effortlessly be incorporated into the clinical image post-processing procedure.

The assessment of neural injury following open heart surgery by physiological tremor analysis.

INTRODUCTION: The appearance of post-operative cognitive dysfunction as a result of open heart surgery has been proven by several studies. Focal and/or sporadic neuron damage emerging in the central nervous system may not only appear as cognitive dysfunction, but might strongly influence features of physiological tremor. MATERIAL AND METHODS: We investigated 110 patients (age: 34-73 years; 76 male, 34 female; 51 coronary artery bypass grafting (CABG), 25 valve replacement, 25 combined open heart surgery, 9 off-pump CABG) before surgery and after open-heart surgery on the 3(rd) to 5(th) post-operative day. The assessment of the physiological tremor analysis was performed with our newly developed equipment based on the Analog Devices ADXL 320 JPC integrated accelerometer chip. Recordings were stored on a PC and spectral analysis was performed by fast Fourier transformation (FFT). We compared power integrals in the 1-4 Hz, 4-8 Hz and 8-12 Hz frequency ranges and these were statistically assessed by the Wilcoxon rank correlation test. RESULTS: We found significant changes in the power spectrum of physiological tremor. The spectrum in the 8-12 Hz range (neuronal oscillation) decreased and a shift was recognised to the lower spectrum (p < 0.01). The magnitude of the shift was not significantly higher for females than for males (p < 0.157). We found no significant difference between the shift and the cross-clamp or perfusion time (p < 0.6450). CONCLUSIONS: The assessment of physiological tremor by means of our novel, feasible method may provide a deeper insight into the mechanism of central nervous system damage associated with open heart surgery.

Comparison of aortic and carotid arterial stiffness parameters in patients with verified coronary artery disease.

BACKGROUND: Arterial stiffness parameters are commonly used to determine the development of atherosclerotic disease. The independent predictive value of aortic stiffness has been demonstrated for coronary events. HYPOTHESIS: The aim of our study was to compare regional and local arterial functional parameters measured by 2 different noninvasive methods in patients with verified coronary artery disease (CAD). We also compared and contrasted these stiffness parameters to the coronary SYNTAX score in patients who had undergone coronary angiography. METHODS: In this study, 125 CAD patients were involved, and similar noninvasive measurements were performed on 125 healthy subjects. The regional velocity of the aortic pulse wave (PWVao) was measured by a novel oscillometric device, and the common carotid artery was studied by a Doppler echo-tracking system to determine the local carotid pulse wave velocity (PWVcar). The augmentation index (AIx), which varies proportionately with the resistance of the small arteries, was recorded simultaneously. RESULTS: In the CAD group, the PWVao and aortic augmentation index (Alxao) values increased significantly (10.1 ± 2.3 m/sec and 34.2% ± 14.6%) compared to the control group (9.6 ± 1.5 m/sec and 30.9% ± 12%; P < 0.05). We observed similar significant increases in the local stiffness parameters (PWVcar and carotid augmentation index [Alxcar]) in patients with verified CAD. Further, we found a strong correlation for PWV and AIx values that were measured with the Arteriograph and those obtained using the echo-tracking method (r = 0.57, P < 0.001 for PWV; and r = 0.65, P < 0.001 for AIx values). CONCLUSIONS: Our results indicate that local and regional arterial stiffness parameters provide similar information on impaired arterial stiffening in patients with verified CAD.

Reference values of aortic pulse wave velocity in a large healthy population aged between 3 and 18 years.

OBJECTIVE: The measurement of aortic pulse wave velocity (PWV(ao)) is an accepted marker in stratifying individual cardiovascular risk in adults. There is an increasing volume of evidence concerning impaired vascular function in different diseases in paediatric populations, but, unfortunately, only a few studies are available on the measurement of normal PWV(ao) values in children. The aim of our study was to determine the reference values of PWV(ao) in a large healthy population using a newly developed technique. METHODS: Three thousand, three hundred and seventy-four healthy individuals (1802 boys) aged 3-18 years were examined by an invasively validated, occlusive, oscillometric device. RESULTS: The mean PWV(ao) values increased from 5.5 ± 0.3 to 6.5 ± 0.3 m/s (P < 0.05) in boys and from 5.6 ± 0.3 to 6.4 ± 0.3 m/s (P < 0.05) in girls. The increase, however, was not constant, and the values exhibited a flat period between the ages of 3 and 8 years in both sexes. The first pronounced increase occurred at the age of 12.1 years in boys and 10.4 years in girls. Moreover, between the ages of 3 and 8 years, the brachial SBP and mean blood pressures increased continuously and gradually, whereas the PWV(ao) remained unchanged. By contrast, beyond the age of 9 years, blood pressure and aortic stiffness trends basically moved together. CONCLUSION: Our study provides the largest database to date concerning arterial stiffness in healthy children and adolescents between the ages of 3 and 18 years, and the technology adopted proved easy to use in large paediatric populations, even at a very young age.

Effects of coronary revascularization with or without cardiopulmonary bypass on plasma levels of asymmetric dimethylarginine.

OBJECTIVES: We measured and compared serum asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and L-arginine levels in patients undergoing coronary artery revascularization. METHODS: Two groups of patients with coronary artery disease were subjected to coronary artery bypass graft surgery (CABG) with cardiopulmonary bypass (CPB; n = 20) or with off-pump CABG surgery (OPCABG; n = 21). Blood samples for measurements of ADMA, SDMA, and L-arginine were withdrawn and determined by liquid chromatography-tandem mass spectrometry from the coronary sinus (CS) and from the peripheral vein. RESULTS: On the basis of the intraoperative (CS) samples, ADMA levels rose in the CPB group (F = 0.416, P < 0.685 and F = 14.751, P < 0.001 for OPCABG and CPB groups, respectively). A similar significant increase of ADMA was observed in the peripheral blood (F = 30.738, P < 0.001) during CPB, whereas ADMA levels remained unchanged during OPCABG. The time course of L-arginine levels was significantly different in the blood samples from CS (F = 3.255, P<0.05), when compared with samples from the peripheral blood (F = 3.255, P < 0.05). The values of the L-arginine/ADMA ratio were significantly higher in the OPCABG group at baseline and on the first postoperative day compared with the results of the CPB group (178.29 ± 11.56 vs. 136.28 ± 13.72 and 129.43 ± 7.08 vs. 106.8 ± 6.9 for OPCABG and CPB groups, respectively). CONCLUSION: Plasma levels of ADMA, SDMA, L-arginine, and L-arginine/ADMA ratio are reliable and feasible markers of an early ischemia-reperfusion injury. During CPB operation, the plasma concentration of ADMA increased significantly and remained elevated until the first postoperative day due to extensive ischemia-reperfusion injury caused by CPB.

Invasive validation of a new oscillometric device (Arteriograph) for measuring augmentation index, central blood pressure and aortic pulse wave velocity.

BACKGROUND: The importance of measuring aortic pulse wave velocity (PWVao), aortic augmentation index (Aix) and central systolic blood pressure (SBPao) has been shown under different clinical conditions; however, information on these parameters is hard to obtain. The aim of this study was to evaluate the accuracy of a new, easily applicable oscillometric device (Arteriograph), determining these parameters simultaneously, against invasive measurements. METHODS: Aortic Aix, SBPao and PWVao were measured invasively during cardiac catheterization in 16, 55 and 22 cases, respectively, and compared with the values measured by the Arteriograph. RESULTS: We found strong correlation between the invasively measured aortic Aix and the oscillometrically measured brachial Aix on either beat-to-beat or mean value per patient basis (r = 0.9, P < 0.001; r = 0.94, P < 0.001), which allowed the noninvasive calculation of the aortic Aix without using generalized transfer function. Similarly strong correlation (r = 0.95, P < 0.001) was found between the invasively measured and the noninvasively calculated central SBPao; furthermore, the BHS assessment of the paired differences fulfilled the 'B' grading. The PWVao values measured invasively and by Arteriograph were 9.41 ± 1.8 m/s and 9.46 ± 1.8 m/s, respectively (mean ± SD); furthermore, the Pearson's correlation was 0.91 (P < 0.001). The limits of agreement were 11.4% for aortic Aix and 1.59 m/s for PWVao. CONCLUSION: Aix, SBPao and PWVao, measured oscillometrically, showed strong correlation with the invasively obtained values. The observed limits of agreement are encouragingly low for accepting the method for clinical use. Our results suggest that the PWVao values, measured by Arteriograph, are close to the true aortic PWV, determined invasively.