Bernhard Hametner

AIT Austrian Institute of Technology | ait · Center for Health & Bioresources

Prevention of cardiovascular disease (CVD) remains one of the largest public health challenges of our time. Identifying individuals at increased cardiovascular risk at an asymptomatic, subclinical stage is of paramount importance for minimizing disease progression as well as the substantial health and economic burden associated with overt CVD. Vasc...

Background Waveform parameters provide approximate data about aortic wave reflection. However, their association with cardiovascular events remains controversial and their role in cardiovascular prediction is unknown. Methods and Results We analyzed participants aged between 40 and 69 from the population‐based CARTaGENE cohort. Baseline pulse wave...

Objective: Heart failure with reduced ejection fraction (HFrEF) is a significant health problem. Early diagnosis, using widely available, cheap methods, remains an important goal. Therefore, we investigated whether individuals with normal left ventricular ejection fraction (EF) can be discriminated from patients with reduced EF with contemporary,...

Background: Renal denervation (RDN) lowers blood pressure (BP), but BP response is variable in individual patients. We investigated whether measures of pulsatile hemodynamics, obtained during 24-hour ambulatory BP monitoring, predict BP drop following RDN. Methods: From the randomized, sham-controlled SPYRAL HTN-OFF MED Pivotal trial, we perform...

Measurements of arterial stiffness and pulsatile hemodynamics undoubtedly led to enormous progress in our understanding of cardiovascular physiology, aging, and development of diseases. Until very recently, these measurements were confined primarily to research laboratories and hospitals and less to the doctor's office. In contrast, we know from th...

The photoplethysmogram (PPG) signal is widely measured by clinical and consumer devices, and it is emerging as a potential tool for assessing vascular age. The shape and timing of the PPG pulse wave are both influenced by normal vascular ageing, changes in arterial stiffness and blood pressure, and atherosclerosis. This review summarises research i...

New findings: What is the central question of this study? First, we validated easy-to-use oscillometric left ventricular ejection time (LVET) against echocardiographic LVET. Second, we investigated progression of left ventricular ejection time index (LVETI), pre-ejection period index (PEPI), total electromechanical systole index (QS2I) and PEP/LVE...

Central (aortic) systolic blood pressure (cSBP) is the pressure seen by the heart, the brain, and the kidneys. If properly measured, cSBP is closer associated with hypertension-mediated organ damage and prognosis, as compared with brachial SBP (bSBP). We investigated 24-hour profiles of bSBP and cSBP, measured simultaneously using Mobilograph devic...

Vascular ageing biomarkers have been found to be predictive of cardiovascular risk independently of classical risk factors, yet are not widely used in clinical practice. In this review we present two basic approaches for using machine learning (ML) to assess vascular age: parameter estimation and risk classification. We then summarize their role in...

Background Reservoir-wave analysis (RWA) separates the arterial waveform into reservoir and excess pressure (XSP) components, where XSP is analogous to flow and related to left ventricular workload. RWA provides more detailed information about the arterial tree than traditional blood pressure (BP) parameters. In end-stage renal disease (ESRD), we h...

Background Cardiovascular risk may be increased in astronauts after long term space flights based on biomarkers indicating premature vascular aging. We tested the hypothesis that 60 days of strict 6° head down tilt bed rest (HDTBR), an established space analog, promotes vascular stiffening and that artificial gravity training ameliorates the respon...

Aortic pulse wave velocity (PWV) is directly related to arterial stiffness. Different methods for the determination of PWV coexist. The aim of this prospective study was to evaluate the prognostic value of PWV in high-risk patients with suspected coronary artery disease undergoing invasive angiography and to compare 3 different methods for assessin...

In December 2019, an outbreak of pneumonia caused by a novel Coronavirus (COVID-19) spread rapidly worldwide. Although the clinical manifestations of COVID-19 are dominated by respiratory symptoms, the cardiovascular system is extensively affected at multiple levels. Due to the unprecedented consequences of the COVID-19 pandemic, the ARTERY society...

Introduction: Microgravity in space is known to cause major alterations in the cardiovascular system. Left ventricular ejection time (LVET) can be measured by the time from the onset point of the pressure wave to the incisura of the dicrotic notch. The aim of this study was to simulate microgravity by head-down tilt bedrest (HDT) to examine changes...

Background Vascular aging, defined by aortic pulse wave velocity (aoPWV), as well as coronary artery calcium (CaC), are emerging risk predictors. Purpose To investigate the prognostic role of functional (vascular aging) and structural (CaC) arterial parameters in individuals without established cardiovascular disease. Methods We utilized our rece...

Re-reflections of arterial pressure waves at the aortic valve and their influence on aortic wave shape are only poorly understood so far. Therefore, the aim of this work is to establish a model enabling the simulation of re-reflection and to test its properties. A mathematical difference equation model is used for the simulations. In this model, th...

Arterial stiffness is an important indicator for vascular aging and an independent predictor for cardiovascular diseases. During space flights or simulated space flights by prolonged head-down tilt bed rest, major cardiovascular alterations occur. However, the changes in arterial stiffness are not fully understood yet. Thus, we aimed to develop a s...

VascAgeNet is a new European network which will join forces in order to refine, harmonize and promote the vascular ageing concept. It aims to bring innovations in cardiovascular research from bench to bedside and to establish assessment of vascular ageing in clinical practice. The interdisciplinary, inter-country and intersectional approach will en...

Cardiovascular mortality is the leading cause of death in Austria, with uncontrolled blood pressure (BP) as a major risk factor. Increased arterial stiffness can indicate high cardiovascular risk. In a screening project, we acquired brachial waveforms with automated oscillometric devices in 45 public pharmacies and at 2 public health events in Uppe...

Cardiovascular Disease (CVD) is the leading cause of morbidity and mortality worldwide, regardless of gender, ethnicity or income. Evidence that vascular age, as opposed to chronological age, is better related to the prognosis of CVD is convincing. Despite recent technological advances for the measurement of vascular ageing, unmet needs remain whic...

Background: Steady state hemodynamics [Stroke Volume - SV, cardiac output, peripheral resistance (Rp)] have attracted researchers in hypertension for decades. However, due to technical difficulties, they never entered clinical medicine. Objective: To investigate the performance of a model-based algorithm, utilizing brachial pressure waveforms obtai...

Introduction: Arterial properties are linked to the presence and severity of coronary artery disease (CAD). Coronary blood flow is strongly and inversely related to arterial stiffness. Thus, the aim of this prospective study was to evaluate the prognostic value of PWV in high-risk patients with suspected CAD and to compare three different methods f...

Purpose/Background/Objectives: According to reservoir-wave theory, excess pressure (XSP) is analogous to flow and related to excess cardiac workload. In end-stage renal disease (ESRD) patients, we have shown that XSPI is associated with increased mortality and is higher in patients with arteriovenous fistula (AVF). Recently AVF has been proposed tr...

Introduction: The concept of re-reflections of blood pressure waves at the heart has been neglected in most models and is only poorly understood so far. Therefore, the aim of this work was to develop a simple mathematical model which is capable to represent the effects of wave travel, wave reflection as well as re-reflection at the aortic valve. Me...

Background: There is evidence of a closer relation between 24 hour aortic systolic blood pressure (aSBP) and left ventricular mass (LVM) compared with 24 hour brachial SBP. However, sample sizes are relatively small and there is some inconsistency in findings. We sought to address this by pooling data from 16 centers in Asia, Europe and Latin Ameri...

Structural and functional dysfunction in both the macro- and microvasculature are a feature of essential hypertension. In a healthy cardiovascular system, the elastic properties of the large arteries ensure that pulsations in pressure and flow generated by cyclic left ventricular contraction are dampened, so that less pulsatile pressure and flow ar...

The Ankle Brachial Index (ABI) is the most commonly used method for the investigation of peripheral artery disease (PAD) in clinical settings, but has a low sensitivity for detecting PAD in asymptomatic patients. It is calculated only based on the systolic blood pressure in the limbs and ignores the shape of the pressure waves. Therefore, we invest...

This is a comment on Salvi et al. Hypertension 2019;74:117-129.

Clustering of arterial blood pressure (BP) waveform parameters could summarize complex information into distinct elements, which could be used to investigate cumulative (nonredundant) associations. We investigated this hypothesis in a large, adult population-based study (ViDA trial [Vitamin D Assessment] trial). To interpret the clusters and evalua...

Background: Arterial reservoir-wave analysis (RWA) - a new model of arterial hemodynamics - separates arterial wave into reservoir pressure (RP) and excess pressure (XSP). The XSP integral (XSPI) has been associated with increased risk of clinical outcomes. The objectives of the present study were to examine the determinants of XSPI in a mixed coh...

This is a preprint of a comment on an article of P. Salvi et al . published in JAHA: DOI: 10.1161/JAHA.118.011440

Background: Pulsatile hemodynamics predict major cardiovascular events. We aimed to provide comprehensive population-based reference values and to compare different measures of pulsatile hemodynamics to define early vascular aging (EVA) as well as healthy vascular aging (HVA). Methods: In 2721 participants from the population-based Heinz Nixdorf...

Background―Reservoir-wave approach (RWA) is an alternative model of arterial hemodynamics based on the assumption that measured arterial pressure is composed of volume-related (reservoir pressure) and wave-related components (excess pressure). However, the clinical utility of RWA remains debatable. Methods and Results― In a single-center cohort of...

See Article by Martins et al and Kowalski et al

The blood pressure category of prehypertension is established by office blood pressure measurement. We investigated the role of 24 h ambulatory blood pressure measurement in subdividing office-based blood pressure categories, establishing the diagnosis of true prehypertension, masked and white-coat hypertension. Furthermore, values of 24 h ambulato...

Background: There is increasing evidence that the method of calibration directly influences the association between brachial systolic blood pressure (bSBP) and estimated aortic systolic blood pressure (aSBP) and subsequently affects prognostic and diagnostic differentiation power of the latter. Objective: The aim of this study was to investigate...

We investigated the relationship between left ventricular mass, and brachial office as well as brachial and central ambulatory systolic blood pressure in 7 European centres. Central systolic pressure was measured with a validated oscillometric device, using a transfer function, and mean/diastolic pressure calibration. M-mode images were obtained by...

Background: Pulsatile hemodynamics are associated with left ventricular filling pressures and diastolic dysfunction. We investigated their relationship with maximum workload and peak oxygen uptake (peak VO2) in patients with exertional dyspnea and preserved left ventricular ejection fraction (LVEF). Methods: Radial waveforms from tonometry were...

The ejection duration (ED) is an important indicator of ventricular function as well as ventriculo-arterial coupling, especially for heart failure with reduced ejection fraction. Thus, the non-invasive oscillometric determination of ED from arterial pressure waves could enhance methods of pulse wave analysis. The aim of this work was to compare dif...

Table S1. Antihypertensive Medication Regimens in the Total Sample (N=517)1 Table S2. Antihypertensive Medication Regimens in the Vitamin D‐Deficient Sample (n=150)1 Table S3. Eigenvalues of the Correlation Matrix and Loadings in the Factor Analysis (Varimax Solution) for Change (Follow‐up Minus Baseline) in Arterial Waveform Parameters Among Tho...

We investigated the relationship between left ventricular mass and brachial office as well as brachial and central ambulatory systolic blood pressure in 7 European centers. Central systolic pressure was measured with a validated oscillometric device, using a transfer function, and mean/diastolic pressure calibration. M-mode images were obtained by...

Background The effects of monthly, high‐dose, long‐term (≥1‐year) vitamin D supplementation on central blood pressure (BP) parameters are unknown. Methods and Results A total of 517 adults (58% male, aged 50–84 years) were recruited into a double‐blinded, placebo‐controlled trial substudy and randomized to receive, for 1.1 years (median; range: 0....

The quantification of arterial wave reflection is an important area of interest in arterial pulse wave analysis. It can be achieved by wave separation analysis (WSA) if both the aortic pressure waveform and the aortic flow waveform are known. For better applicability, several mathematical models have been established to estimate aortic flow solely...

Purpose of review: Arterial pulse waveform analysis has a long tradition but has not pervaded medical routine yet. This review aims to answer the question whether the methodology is ready for prime time use. The current methodological consensus is assessed, existing technologies for waveform measurement and pulse wave analysis are discussed, and f...

Journal of Human Hypertension is exclusively concerned with all clinical aspects of human hypertension. The journal publishes fully refereed original research papers from around the world.

Background: Systolic left ventricular function strongly influences the blood pressure waveform. Therefore, pressure-derived parameters might potentially be used as non-invasive, diagnostic markers of left ventricular impairment. The aim of this study was to investigate the performance of pressure-based parameters in combination with electrocardiog...

This paper aims to summarize and map contemporary views on some contentious aspects of arterial hemodynamics that have remained unresolved despite years of research. These were discussed during a workshop entitled Arterial hemodynamics: past, present and future held in London on June 14 and 15, 2016. To do this we formulated a list of potential con...

Background: Afterload reduction is a cornerstone in the management of patients with heart failure (HF) and reduced ejection fraction. However, arterial load and the effect of HF therapies on afterload might vary between individuals. Tailoring vasoactive medicines to patients with HF based upon better understanding of arterial afterload may enable...