Comment on Savioli et al. Mild Head Trauma: Is Antiplatelet Therapy a Risk Factor for Hemorrhagic Complications? Medicina 2021, 57, 357.

We read the article of Savioli G. et al. [...].

Atrial fibrillation at mid-term after bioprosthetic aortic valve replacement ­ implications for anti-thrombotic therapy.

BACKGROUND: Little is known about mid-term (3-month) postoperative atrial fibrillation (MT-POAF) in patients treated with bioprosthetic aortic valve replacement (BAVR). The aim of this study was to describe the natural history, identify the predictors and investigate the potential consequences in terms of anti-thrombotic therapy. METHODS AND RESULTS: During a longitudinal, prospective study, 219 patients were treated with BAVR early (7 days) and at mid-term postoperatively (30 and 90 days). POAF was monitored and risk factors were identified on logistic regression analysis. History of previous AF (OR, 3.08; 95% CI: 1.35-6.98), early POAF (OR, 5.93; 95% CI: 2.96-11.8), and BMI (per 5 kg/m(2): OR, 1.46; 95% CI: 1.03-2.09), were independent predictors for MT-POAF whereas sex, age and Euroscore were not. Results were identical when restricted to the 176 patients free from preoperative AF. In this subgroup, 36 patients (20.4%) had MT-POAF; 33 out of 174 (18.7%) would have required anticoagulation (CHA2DS2VASc score ≥ 1). Conversely, patients with BMI <27.7 and sinus rhythm at early follow-up had a very low risk of MT-POAF (OR, 0.16; 95% CI: 0.06-0.42). CONCLUSIONS: There was a higher than expected occurrence of MT-POAF in patients treated with BAVR, particularly in overweight patients with early POAF. This raises the question of implementing an anti-thrombotic therapy in these patients at higher risk of delayed atrial arrhythmia.

Echocardiographic abnormalities in the assessment of cardiac organ damage in never-treated hypertensive patients.

Hypertension-related cardiac organ damage, other than left ventricular (LV) hypertrophy (LVH), has been described: in particular, concentric remodeling, LV diastolic dysfunction (DD), and left atrial (LA) enlargement are significantly associated with cardiovascular morbility and mortality in different populations. This study evaluated the prevalence of these latter morphofunctional abnormalities, in never-treated essential hypertensive patients and the role of such a serial assessment of hypertensive cardiac damage in improving cardiovascular risk stratification in these patients. A total of 100 never-treated essential hypertensive subjects underwent a complete clinical and echocardiographic evaluation. Left ventricular morphology, systolic and diastolic function, and LA dimension (linear and volume) were evaluated by echocardiography. Left ventricular hypertrophy was present in 14% of the patients, whereas concentric remodeling was present in 25% of the subjects. Among patients free from LV morphology abnormalities, the most frequent abnormality was LA enlargement (global prevalence 57%); the percentage of patients with at least one parameter consistent with DD was 22% in the entire population, but DD was present as the only cardiac abnormality in 1% of our patient. Left atrial volume indexed for body surface area was the most sensitive parameter in identifying hypertension-related cardiac modification. The global prevalence of cardiac alteration reached 73% in never-treated hypertensive patients. Left ventricular remodeling and LA enlargement evaluation may grant a better assessment of cardiac organ damage and cardiovascular risk stratification of hypertensive patients without evidence of LVH after routine examination.

Accuracy of a new instrument for noninvasive evaluation of pulse wave velocity: the Arterial sTiffness faitHful tOol aSsessment project.

BACKGROUND: Large artery stiffness, assessed by carotid--femoral pulse wave velocity (cfPWV), is a major risk factor for cardiovascular events, commonly used for risk stratification. Currently, the reference device for noninvasive cfPWV is SphygmoCor but its cost and technically challenging use limit its diffusion in clinical practice. AIM: To validate a new device for noninvasive assessment of cfPWV, ATHOS (Arterial sTiffness faitHful tOol aSsessment), designed in collaboration with the Politecnico di Torino, against the reference noninvasive method represented by SphygmoCor. METHODS: Ninety healthy volunteers were recruited. In each volunteer, we assessed cfPWV, using SphygmoCor (PWVSphygmoCor) and ATHOS (PWVATHOS) devices in an alternate fashion, following the ARTERY Society guidelines. The accuracy was assessed by Bland--Altman plot, and reproducibility was assessed by interoperator correlation coefficient (ICC). RESULTS: Mean PWVATHOS and mean PWVSphygmoCor were 7.88 ±â€Š1.96 and 7.72 ±â€Š1.95 m/s, respectively. Mean difference between devices was 0.15 ±â€Š0.56 m/s, with a high correlation between measurements (r = 0.959, P < 0.001). Considering only PWV values at least 8 m/s (n = 30), mean difference was 0.1 ±â€Š0.63 m/s. The ICC was 97.7% with ATHOS. CONCLUSION: ATHOS showed an excellent level of agreement with SphygmoCor, even at high PWV values, with a good reproducibility. Its simplicity of use could help increase clinical application of PWV assessment, improving patients' cardiovascular risk stratification.

Central pulse pressure is inversely associated with proximal aortic remodelling.

OBJECTIVES: Hypertension leads to aortic stiffening and dilatation but unexpected data from the Framingham Heart Study showed an inverse relationship between brachial pulse pressure and aortic diameter. Aortic dilatation would not only lead to lower pulse pressure but also to a worse prognosis (cardiac events, heart failure). Invasive pressure may be more informative but data are lacking. AIM: This study evaluated the relationship between invasively measured central blood pressure and proximal aortic diameter. METHODS: In 71 consecutive patients referred to invasive haemodynamic study, proximal aortic remodelling was evaluated in terms of Z-score, comparing diameters measured at the sinus of Valsalva to the diameter expected according to patients' age, sex and body height. Pressures were recorded directly in the proximal aorta by means of a catheter before coronary assessment. RESULTS: The mean invasive aortic SBPs and DBPs were 146 ±â€Š23 and 78 ±â€Š13 mmHg, respectively, giving a central pulse pressure (cPP inv) of 68 ±â€Š21 mmHg. Proximal aortic diameter was 34.9 ±â€Š19.4 mm, whereas Z-score was -0.3 ±â€Š1.7. Patients with higher cPPinv showed a significantly lower Z-score (-0.789 vs. 0.155, P = 0.001). cPPinv was inversely related to Z-score (R = -0.271, P = 0.022) independently from age, mean blood pressure and heart rate (ß = -0.241, P = 0.011). CONCLUSION: Aortic root Z-score is inversely associated with invasively measured central pulse pressure in a cohort of patients undergoing invasive coronary assessment. Remodelling at the sinuses of Valsalva may be a compensatory mechanism to limit pulse pressure.

Prognostic role of the ascending aorta dilatation in patients with arterial hypertension.

BACKGROUND: Ascending aorta (ASC) dilatation (AAD) is a common finding in arterial hypertension, affecting about 15% of hypertensive patients. AAD is associated with an increase in cardiac and vascular hypertension-related organ damage, but its prognostic role is unknown. The aim of the study was to evaluate the prognostic value of AAD as predictor of cardiovascular events in essential hypertensive patients. METHODS: Recruited patients underwent two-dimensional transthoracic echocardiography from 2007 to 2013 and followed-up for cardiovascular events until November 2018 by phone call and hospital information system check. ASC diameter and AAD were defined using both absolute and scaled definitions. Four hundred and twenty-three hypertensive patients were included in our study. RESULTS: During a median follow-up of 7.4 years (interquartile range 5.6-9.1 years), 52 events were observed. After adjusting for age, sex and BSA, both ASC diameter and AAD definition, according to ARGO-SIIA project, resulted associated with a greater risk of cardiovascular event (both P < 0.010), even after adjusting for major confounders (both P < 0.010). Moreover, we observed that the assessment of ASC improves risk stratification compared with pulse wave velocity alone, and that in absence of AAD, sinus of valsalva dilatation lost any prognostic value (P = 0.262). CONCLUSIONS: ASC diameter and AAD are both associated with a greater risk of cardiovascular events. ASC should be assessed to optimize risk stratification in hypertensive patients and its dilatation may be considered as a surrogate for vascular organ damage.

Proximal aortic diameter evolution in hypertensive patients with mild-to-moderate aortic dilatation: a 5-year follow-up experience.

BACKGROUND: Aortic dilatation is common in hypertensive patients and is associated with higher risk of cardiovascular events. Parameters predicting further dilatation during lifetime are poorly understood. AIM: To predict the midterm aortic diameter evolution in a cohort of hypertensive patients with known aortic dilatation at Sinus of Valsalva (SOV) level. METHODS: We prospectively analyzed a cohort of essential hypertensive outpatients without any other known risk factor for aortic dilatation. They underwent serial echocardiographic evaluations from 2003 to 2016. RESULTS: Two hundred and forty-two hypertensive outpatients with a mild-to-moderate (37-53 mm) aortic dilatation were followed up for at least 5 years. Mean growth rate was 0.08 ±â€Š0.35 mm/year. No clinical or anthropometric parameters were significantly different in patients with and without aortic diameter increase. Aortic z score (number of standard deviations from the average value observed in the general population) at baseline was inversely associated with growth rate (R 0.04, P < 0.05). Aortic diameter at first visit, demographic and echocardiographic variables were major determinants of aortic diameter at second visit, accounting for about 90% of its total variability. CONCLUSION: Mean growth rate of proximal aorta in hypertensive patients with known aortic dilatation was of about 0.1 mm/year. Dilatation over time is slower in patients with increased rather than normal aortic z score. Eventually, it could be possible to reliably predict aortic diameter at few months from first visit.

Current assessment of pulse wave velocity: comprehensive review of validation studies.

OBJECTIVE: Carotid-femoral pulse wave velocity (PWV) is considered the gold standard for arterial stiffness assessment in clinical practice. A large number of devices to measure PWV have been developed and validated. We reviewed different validation studies of PWV estimation techniques and assessed their conformity to the Artery Society Guidelines and the American Heart Association recommendations. METHODS: Pubmed and Medline (1995-2017) were searched to identify PWV validation studies. Of the 96 article retrieved, 26 met the inclusion criteria. RESULTS: Several devices had been developed and validated to noninvasively measure arterial stiffness, using applanation tonometry (SphygmoCor, PulsePen), piezoelectric mechanotransducers (Complior), cuff-based oscillometry (Arteriograph, Vicorder and Mobil-O-Graph), photodiode sensors (pOpmètre) and devices assessing brachial-ankle pulse wave velocity and cardiac-ankle PWV. Ultrasound technique and MRI remain confined to clinical research. Good agreement was found with the Artery Society Guidelines. Two studies (Complior, SphygmoCor Xcel) showed best adherence with the guidelines. In Arteriograph, MRI, ultrasound and SphygmoCor Xcel validation studies sample size was smaller than the minimum suggested by the guidelines. High discrepancies between devices were shown in distance estimation: in two studies (Arteriograph, Complior) path length was estimated in conformity to the guidelines. Transit time was calculated using the intersecting tangent method, but in two studies (Vicorder, pOpmètre) best agreement was found using the maximum of the second derivative. Six studies reached the accuracy level 'excellent' defined in the Artery guidelines. CONCLUSION: Method to assess transit time and path length need validation in larger populations. Further studies are required in different risk population to implement clinical applicability of every device.

Multiscale mathematical modeling vs. the generalized transfer function approach for aortic pressure estimation: a comparison with invasive data.

We aimed to evaluate the performance of a mathematical model and currently available non-invasive techniques (generalized transfer function (GTF) method and brachial pressure) in the estimation of aortic pressure. We also aimed to investigate error dependence on brachial pressure errors, aorta-to-brachial pressure changes and demographic/clinical conditions. Sixty-two patients referred for invasive hemodynamic evaluation were consecutively recruited. Simultaneously, the registration of the aortic pressure using a fluid-filled catheter, brachial pressure and radial tonometric waveform was recorded. Accordingly, the GTF device and mathematical model were set. Radial invasive pressure was recorded soon after aortic measurement. The average invasive aortic pressure was 141.3 ± 20.2/76 ± 12.2 mm Hg. The simultaneous brachial pressure was 144 ± 17.8/81.5 ± 11.7 mm Hg. The GTF-based and model-based aortic pressure estimates were 133.1 ± 17.3/82.4 ± 12 and 137 ± 21.6/72.2 ± 16.7 mm Hg, respectively. The Bland-Altman plots showed a marked tendency to pressure overestimation for increasing absolute values, with the exclusion of mathematical model diastolic estimations. The systolic pressure was increased from the aortic to radial locations (7.5 ± 19 mm Hg), while the diastolic pressure was decreased (3.8 ± 9.8 mm Hg). The brachial pressure underestimated the systolic and overestimated diastolic intra-arterial radial pressure. GTF errors were independently correlated with the variability in pulse pressure amplification and with the brachial error. Errors of the mathematical model were related to only demographic and clinical conditions. Neither a multiscale mathematical model nor a generalized transfer function device substantially outperformed the oscillometric brachial pressure in the estimation of aortic pressure. Mathematical modeling should be improved by including further patient-specific conditions, while the variability in pulse pressure amplification may hamper the performance of the GTF method in patients at the risk of coronary artery disease.

Prolonged QT interval and reduced heart rate variability in patients with uncomplicated essential hypertension.

A prolonged QT interval is a risk factor for ischemic heart disease in hypertensive subjects. Heart rate variability (HRV) is both an index of autonomic function and an important prognostic factor in several diseases. The aim of the present study was to evaluate the relation between a prolonged QT interval and autonomic nervous system function in patients with untreated uncomplicated essential hypertension. Two hundred and fifteen untreated patients with essential hypertension underwent a Holter ECG equipped with software dedicated to HRV and QT analyses. Nine percent of the patients showed a corrected QT (QTc) >or=440 ms. The HRV indexes in the time domain (SDNN, SDNN index, RMSSD, and pNN50) were significantly reduced in the patients with a prolonged QTc compared to those with a normal QTc (SDNN 24 h: 126.4+/-29.9 vs. 143.9+/-35.4 ms, p=0.02; SDNN index [nighttime]: 85.9+/-32.4 vs. 115.5+/-36.7 ms, p=0.0006; RMSSD 24 h: 22.2+/-7.7 vs. 31.2+/-13.0 ms, p=0.0007; pNN50 24 h: 4.4+/-4.9 vs. 9.7+/-8.4%, p=0.0006). The linear correlation analysis between QTc length and HRV parameters showed a significant negative correlation with all the time-domain indexes. Such a correlation was maintained for RMSSD 24 h, pNN50 24 h and SDNN index (nighttime) after correction for gender and age. The present study shows that, even prior to the development of cardiac hypertensive disease, a prolongation of the QTc and a reduced HRV, both markers of cardiovascular risk, coexist in a proportion of patients with untreated essential hypertension. Further studies are warranted to evaluate whether the combination of such markers can identify hypertensive patients at risk for life-threatening arrhythmias and sudden death. (Hypertens Res 2008; 31: 2003-2010).

Evaluation of aortic stiffness by a new simplified 2D speckle tracking analysis.

Arterial stiffness is a marker of cardiovascular damage and an independent predictor of major cardiovascular events, usually assessed via Carotid-Femoral Pulse Wave Velocity (cfPWV). The aim of this study was to test the feasibility and usefulness of aortic strain analysis using a simplified transthoracic echocardiography (TTE) speckle-tracking (ST) based method. 60 consecutive patients with normal blood pressure and aortic dimensions underwent TTE and cfPWV evaluation. Strain analysis was performed on the largest section of the ascending aorta (aA) with a dedicated software; three couples of speckles were identified within the anterior and posterior aortic wall and transverse segments connecting each couple traced. Peak ascending Aorta Strain (PaAS) was defined as the averaged peak percentage deformation of these segments during the cardiac cycle; aortic stiffness index ß2 was defined as 100 × Ln(SBP/DBP)/PaAS. 17 patients were excluded for suboptimal TTE images. In the 43 analyzed individuals (male 58%, age 63 years) PaAS was 5.5 [3.7-8.6] % with excellent inter and intra observer reproducibility (ICC 95% for both). PaAS showed significant correlation with age (r = - 0.64), aA diameter (r = - 0.45), cfPWV (r = - 0.41), stroke volume (r = - 0.41) and heart rate (r = - 0.49). Age remained the only independent determinant of PaAS in a multivariate analysis. ß2 (10.8 [5.9-15.0]) showed significant direct correlation with age, Pulse pressure, aA diameter and cfPWV. A simplified strain analysis of the ascending aorta is technically feasible with good reproducibility; PaAS and ß2 index correlate well with established parameters of arterial stiffness and might represent a new index in evaluating vascular biomechanics.

A simple UHPLC-PDA method with a fast dilute-and-shot sample preparation for the quantification of canrenone and its prodrug spironolactone in human urine samples.

INTRODUCTION: Nowadays, the treatment of hypertension represents an important issue, particularly in developed countries. While in most cases the standard therapeutic approaches, consisting in the administration of 1 to 3 drugs, are adequate to reach adequate blood pressure levels, in some cases more drugs are needed: this condition is called "resistant hypertension". In this context, the administration of a diuretic, such as spironolactone or canrenoate salts, represents a standard practice. Since a reliable discrimination of real cases of resistant hypertension from cases of poor therapeutic adherence is currently difficult to obtain, the adoption of therapeutic drug monitoring has been suggested as a useful tool for this purpose. In this work, the authors developed and validated a simple, cheap and fast dilute-and-shot method with UHPLC-PDA analysis for the quantification of spironolactone and its metabolite canrenone in human urine samples. METHODS: Standards and quality controls were prepared in urine. Only 100 µL of sample were added with 80 µL of internal standard (6,7-dimethyl-2,3-di(2-pyridyl)quinoxaline) working solution and 820 µL of phosphate buffer 10 mM pH 3.2 (phase A):acetonitrile (phase B) 90:10 v:v solution. Chromatographic separation was performed on an Acquity® UPLC HSS T3 1.8 µm 2.1 × 150 mm column, with a binary gradient for 11 min at 40 °C. RESULTS: Accuracy, intra-day and inter-day precision, selectivity and sensitivity fitted FDA guidelines for all analytes (LLOQ and LOD were 156.25 ng/mL and 78.12 ng/mL, respectively, for both analytes) and recovery resulted high and reproducible. Method performances were tested on urine samples from hypertensive patients with good results. DISCUSSION: This simple analytical method could represent a useful tool for the management of antihypertensive therapy.

Accuracy of transthoracic echocardiography in the assessment of proximal aortic diameter in hypertensive patients: comparison with cardiac magnetic resonance.

BACKGROUND: Accurate and reproducible measurements of proximal thoracic aorta diameters are essential in the diagnosis and follow-up of patients with aortic dilatation, a condition particularly common in hypertensive patients. AIM: to evaluate the accuracy of transthoracic echocardiography (TTE) in comparison with cardiac magnetic resonance (CMR) for the assessment of proximal thoracic aorta diameters in a cohort of hypertensive patients. METHODS: A total of 75 essential hypertensive outpatients previously evaluated by TTE and than by CMR were included in the study. We specifically compared the two techniques at the level of sinuses of Valsalva (SoV) and ascending aorta (Asc) diameter. For the TTE images, the inner edge-to-inner edge and leading edge-to-leading edge conventions were compared. RESULTS: TTE and CMR diameters were significantly related (SoV: r 0.931, P < 0.001; Asc: r 0.949, P < 0.001) when the leading edge-to-leading edge convention was used. Mean difference between CMR and TTE diameters was 2.49 ±â€Š2.01 mm at the level of SoV and 1.13 ±â€Š1.77 mm at the level of Asc. Correlation was good also for the TEE diameters measured by inner edge-to-inner edge convention (SoV: r 0.936, P < 0.001; Asc: r 0.947, P < 0.001). Comparing the two approaches in the evaluation of Asc, inner edge-to-inner edge showed a trend to a better correlation with CMR measurements than leading edge-to-leading edge, with a good interobserver and intraobserver agreement. CONCLUSION: The results of the current study suggest that TTE could be a reliable tool to assess proximal aorta diameters in hypertensive patients.

UHPLC-MS/MS method with sample dilution to test therapeutic adherence through quantification of ten antihypertensive drugs in urine samples.

Nowadays, hypertension represents an important health problem, particularly in developed countries. In some cases the standard therapeutic approaches are not able to reestablish the normal blood pressure values: this condition is called "resistant hypertension". However, a fraction of cases of resistant hypertension are actually due to poor adherence to the prescribed therapy. Therapeutic Drug Monitoring could represent a direct and useful tool to correctly identify non-compliant patients. Nevertheless, high throughput methods for the simultaneous monitoring of a wide panel of drugs in the same analysis are lacking and, furthermore, there is not a generally acknowledged "standard" matrix for this test (plasma or urine). In this work, we validated a UHPLC-MS/MS assay to quantify ten among the most used antihypertensive agents in urine samples, covering all the current classes: amlodipine, atenolol, clonidine, chlortalidone, doxazosin, hydrochlorothiazide, nifedipine, olmesartan, ramipril and telmisartan. Both standards and quality controls were prepared in urine matrix. Only 100µL of each sample were added with 40µL of internal standard and 860µL of water:acetonitrile 90:10, acidified with 0.05% formic acid. Chromatographic separation was performed on an Acquity® UPLC HSS T3 1.8µm 2.1×150mm column, with a gradient of water and acetonitrile, both added with 0.05% formic acid. Accuracy, intra-day and inter-day precision fitted FDA guidelines for all analytes, while matrix effects resulted reproducible among different urine lots. Method performances were tested on urine samples from hypertensive patients with good results. This simple analytical method could represent a useful tool for the management of antihypertensive therapy.

Out of proportion proximal aortic remodeling: A subclinical marker of early vascular ageing? A systematic review.

INTRODUCTION: Proximal aorta stiffens and dilates with aging. Aortic stiffening is a well known process, carrying prognostic implications. On the contrary, few data are available about proximal aorta dilatation. It is not known if "out of proportion" aortic remodeling, i.e. in excess for age, sex and body size, could be a marker of early vascular ageing; there is controversy on how it would be accelerated by classical risk factors or would associate with validated markers of cardiovascular organ damage. AIM: We conducted a systematic review in order to evaluate the determinants of proximal aortic dimensions, focusing on the association with arterial hypertension, cardiovascular risk factors and markers of organ damage. DETERMINANTS OF PROXIMAL AORTA REMODELING: Age, gender and body size explain 40-50% of the variability of aortic dimensions; genetic predisposition accounts for nearly 20%. Among cardiovascular risk factors obesity and hypertension seem to be associated with faster outward aortic remodeling. Arterial hypertension would account for a 0.60-0.78 mm greater diameter at the ascending aorta. Moreover, in hypertension, left ventricular mass showed a strict association with aortic diameter in nearly all studies. Other classical risk factors for atherogenesis such as dyslipidemia and smoking showed a weak influence on proximal aortic dimensions. No study reported a greater aortic remodeling in diabetics. CONCLUSIONS: "Out of proportion" proximal aortic remodeling, could represent a subclinical marker of early vascular ageing, describing the cumulative influence of genetic predisposition, arterial hypertension and obesity.

Correction: Central Pressure Appraisal: Clinical Validation of a Subject-Specific Mathematical Model.

[This corrects the article DOI: 10.1371/journal.pone.0151523.].

Central Pressure Appraisal: Clinical Validation of a Subject-Specific Mathematical Model.

INTRODUCTION: Current evidence suggests that aortic blood pressure has a superior prognostic value with respect to brachial pressure for cardiovascular events, but direct measurement is not feasible in daily clinical practice. AIM: The aim of the present study is the clinical validation of a multiscale mathematical model for non-invasive appraisal of central blood pressure from subject-specific characteristics. METHODS: A total of 51 young male were selected for the present study. Aortic systolic and diastolic pressure were estimated with a mathematical model and were compared to the most-used non-invasive validated technique (SphygmoCor device, AtCor Medical, Australia). SphygmoCor was calibrated through diastolic and systolic brachial pressure obtained with a sphygmomanometer, while model inputs consist of brachial pressure, height, weight, age, left-ventricular end-systolic and end-diastolic volumes, and data from a pulse wave velocity study. RESULTS: Model-estimated systolic and diastolic central blood pressures resulted to be significantly related to SphygmoCor-assessed central systolic (r = 0.65 p <0.0001) and diastolic (r = 0.84 p<0.0001) blood pressures. The model showed a significant overestimation of systolic pressure (+7.8 (-2.2;14) mmHg, p = 0.0003) and a significant underestimation of diastolic values (-3.2 (-7.5;1.6), p = 0.004), which imply a significant overestimation of central pulse pressure. Interestingly, model prediction errors mirror the mean errors reported in large meta-analysis characterizing the use of the SphygmoCor when non-invasive calibration is performed. CONCLUSION: In conclusion, multi-scale mathematical model predictions result to be significantly related to SphygmoCor ones. Model-predicted systolic and diastolic aortic pressure resulted in difference of less than 10 mmHg in the 51% and 84% of the subjects, respectively, when compared with SphygmoCor-obtained pressures.

Modelling and subject-specific validation of the heart-arterial tree system.

A modeling approach integrated with a novel subject-specific characterization is here proposed for the assessment of hemodynamic values of the arterial tree. A 1D model is adopted to characterize large-to-medium arteries, while the left ventricle, aortic valve and distal micro-circulation sectors are described by lumped submodels. A new velocity profile and a new formulation of the non-linear viscoelastic constitutive relation suitable for the {Q, A} modeling are also proposed. The model is firstly verified semi-quantitatively against literature data. A simple but effective procedure for obtaining subject-specific model characterization from non-invasive measurements is then designed. A detailed subject-specific validation against in vivo measurements from a population of six healthy young men is also performed. Several key quantities of heart dynamics-mean ejected flow, ejection fraction, and left-ventricular end-diastolic, end-systolic and stroke volumes-and the pressure waveforms (at the central, radial, brachial, femoral, and posterior tibial sites) are compared with measured data. Mean errors around 5 and 8%, obtained for the heart and arterial quantities, respectively, testify the effectiveness of the model and its subject-specific characterization.

Cardiac Organ Damage and Arterial Stiffness in Autonomic Failure: Comparison With Essential Hypertension.

Autonomic failure (AF) is characterized by orthostatic hypotension, supine hypertension, and increased blood pressure (BP) variability. AF patients develop cardiac organ damage, similarly to essential hypertension (EH), and have higher arterial stiffness than healthy controls. Determinants of cardiovascular organ damage in AF are not well known: both BP variability and mean BP values may be involved. The aim of the study was to evaluate cardiac organ damage, arterial stiffness, and central hemodynamics in AF, compared with EH subjects with similar 24-hour BP and a group of healthy controls, and to evaluate determinants of target organ damage in patients with AF. Twenty-seven patients with primary AF were studied (mean age, 65.7±11.2 years) using transthoracic echocardiography, carotid-femoral pulse wave velocity, central hemodynamics, and 24-hour ambulatory BP monitoring. They were compared with 27 EH subjects matched for age, sex, and 24-hour mean BP and with 27 healthy controls. AF and EH had similar left ventricular mass (101.6±33.3 versus 97.7±28.1 g/m(2), P=0.59) and carotid-femoral pulse wave velocity (9.3±1.8 versus 9.2±3.0 m/s, P=0.93); both parameters were significantly lower in healthy controls (P<0.01). Compared with EH, AF patients had higher augmentation index (31.0±7.6% versus 26.1±9.2%, P=0.04) and central BP values. Nighttime systolic BP and 24-hour systolic BP predicted organ damage, independent of BP variability. AF patients develop hypertensive heart disease and increased arterial stiffness, similar to EH with comparable mean BP values. Twenty-four-hour and nighttime systolic BP were determinants of cardiovascular damage, independent of BP variability.