Zsófia Lenkey

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 Pearsons 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.

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.

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 (PWVao) 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 PWVao values in children. The aim of our study was to determine the reference values of PWVao 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 PWVao 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 PWVao 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.

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

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.

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 µM-stimulated peak aggregation (Aggmax), 6-minute late aggregation (Agglate) 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 Aggmax 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 (Aggmax: 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 (Aggmax: 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.

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

ObjectivesWe measured and compared serum asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and L-arginine levels in patients undergoing coronary artery revascularization. MethodsTwo 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. ResultsOn 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). ConclusionPlasma 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.

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.

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 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 3rd to 5th 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.