Endovascular Treatment of Flow-Limiting Iliofemoral Stenosis Improves Left Ventricular Diastolic Function in Patients With HFpEF by Reducing Aortic Pulsatile Load.

BACKGROUND: Recent research indicates that there is a high prevalence of heart failure with preserved ejection fraction in patients with peripheral artery disease. We hypothesized that endovascular treatment (EVT) of flow-limiting peripheral stenosis improves left ventricular (LV) diastolic function. METHODS: Thirty patients with symptomatic peripheral artery disease and heart failure with preserved ejection fraction according to Heart Failure Association-preserved ejection fraction score who were scheduled for EVT or angiography were investigated at baseline, the day after EVT (n=25) or angiography (control, n=5), and at 4 months follow-up. Peripheral hemodynamics were determined by the total peripheral resistance, common femoral artery flow, and ankle brachial index. Aortic function was measured by arterial compliance, augmentation index, and pulse wave velocity. Aortic pulsatile load was estimated as the characteristic impedance of the proximal aorta and the magnitude of wave reflection (reflection coefficient). LV mass index, LV mean wall thickness, and systolic and diastolic function were assessed using echocardiography. Patient-centered outcomes were treadmill walking distance and New York Heart Association class. RESULTS: After EVT, peripheral hemodynamics changed significantly with a decrease in total peripheral resistance and an increase in common femoral artery flow and ankle brachial index. Aortic function improved after EVT, with significantly reduced augmentation index and pulse wave velocity and increased compliance immediately and at follow-up, resulting in a reduction in aortic pulsatile load (characteristic impedance of the proximal aorta and reflection coefficient). Concurrently, LV diastolic function improved after EVT compared with control, acutely and at follow-up, with increased septal and lateral e´ velocities and decreased E/e´ and left atrial volume index. The LV mass index and LV mean wall thickness decreased at follow-up. The New York Heart Association class and treadmill walking distance improved post-EVT at follow-up. Augmentation index, pulse wave velocity, and arterial compliance were identified as independent contributors to E/e´. CONCLUSIONS: Endovascular treatment of flow-limiting iliofemoral stenosis reduces aortic pulsatile load and concurrently lowers total peripheral resistance. This beneficial effect is associated with an acute and sustained improvement of left ventricular diastolic function. REGISTRATION: URL: http://www.clinicaltrials.gov; Unique identifier: NCT02728479.

The role of pulse wave analysis indexes for critically ill patients: a narrative review.

Objective.Arterial pulse wave analysis (PWA) is now established as a powerful tool to investigate the cardiovascular system, and several clinical studies have shown how PWA can provide valuable prognostic information over and beyond traditional cardiovascular risk factors. Typically these techniques are applied to chronic conditions, such as hypertension or aging, to monitor the slow structural changes of the vascular system which lead to important alterations of the arterial PW. However, their application to acute critical illness is not currently widespread, probably because of the high hemodynamic instability and acute dynamic alterations affecting the cardiovascular system of these patients.Approach.In this work we propose a review of the physiological and methodological basis of PWA, describing how it can be used to provide insights into arterial structure and function, cardiovascular biomechanical properties, and to derive information on wave propagation and reflection.Main results.The applicability of these techniques to acute critical illness, especially septic shock, is extensively discussed, highlighting the feasibility of their use in acute critical patients and their role in optimizing therapy administration and hemodynamic monitoring.Significance.The potential for the clinical use of these techniques lies in the ease of computation and availability of arterial blood pressure signals, as invasive arterial lines are commonly used in these patients. We hope that the concepts illustrated in the present review will soon be translated into clinical practice.

VEGF Polymorphisms (VEGF-936 C/T, VEGF-634 G/C and VEGF-2578 C/A) and Cardiovascular Implications in Long COVID Patients.

The COVID-19 pandemic has raised awareness of the virus's long-term non-pulmonary consequences. This study examined the relationship between genetic polymorphisms of VEGF and cardiac dysfunction and subclinical atherosclerosis in patients recovering from COVID-19. This study included 67 patients previously diagnosed with COVID-19. VEGF-936C/T, VEGF-634G/C, and VEGF-2578C/A statuses were determined. Conventional echocardiography and arterial parameters assessments were performed at inclusion and at six months after the first assessment. For VEGF-936C/T, dominant and over-dominant models showed a significant increase in ejection fraction at six months after COVID (p = 0.044 and 0.048) and was also a predictive independent factor for the augmentation index (ß = 3.07; p = 0.024). The dominant model showed a rise in RV-RA gradient (3.702 mmHg) (p = 0.028 95% CI: 0.040-7.363), with the over-dominant model indicating a greater difference (4.254 mmHg) (p = 0.025 95% CI: 0.624-7.884). The findings for VEGF-634G/C were not statistically significant, except for a difference in TAPSE during initial evaluation, using the codominant model. For VEGF-2578C/A, a difference in ventricular filling pressure (E/E'ratio) was best described under the recessive model. Our research suggests that the VEG-936C/T genotype may impact the baseline level and subsequent changes in cardiac function and subclinical atherosclerosis. These findings offer valuable insights into the complex correlation between genetic polymorphisms and cardiovascular disfunction in long COVID patients.

Temporal Convolutional Neural Network-Based Prediction of Vascular Health in Elderly Women Using Photoplethysmography-Derived Pulse Wave during Exercise.

(1) Background: The objective of this study was to predict the vascular health status of elderly women during exercise using pulse wave data and Temporal Convolutional Neural Networks (TCN); (2) Methods: A total of 492 healthy elderly women aged 60-75 years were recruited for the study. The study utilized a cross-sectional design. Vascular endothelial function was assessed non-invasively using Flow-Mediated Dilation (FMD). Pulse wave characteristics were quantified using photoplethysmography (PPG) sensors, and motion-induced noise in the PPG signals was mitigated through the application of a recursive least squares (RLS) adaptive filtering algorithm. A fixed-load cycling exercise protocol was employed. A TCN was constructed to classify flow-mediated dilation (FMD) into "optimal", "impaired", and "at risk" levels; (3) Results: TCN achieved an average accuracy of 79.3%, 84.8%, and 83.2% in predicting FMD at the "optimal", "impaired", and "at risk" levels, respectively. The results of the analysis of variance (ANOVA) comparison demonstrated that the accuracy of the TCN in predicting FMD at the impaired and at-risk levels was significantly higher than that of Long Short-Term Memory (LSTM) networks and Random Forest algorithms; (4) Conclusions: The use of pulse wave data during exercise combined with the TCN for predicting the vascular health status of elderly women demonstrated high accuracy, particularly in predicting impaired and at-risk FMD levels. This indicates that the integration of exercise pulse wave data with TCN can serve as an effective tool for the assessment and monitoring of the vascular health of elderly women.

Arteriovenous Oscillometric Plethysmography for Fistula Functional Testing.

INTRODUCTION: The aim of the presented prospective observational study was to evaluate the effect of fistula flow on peripheral wave morphology and pulse wave velocity by means of the oscillometric Vicorder®-device with the purpose of fistula surveillance. METHODS: Digitized and normalized curves of 53 haemodialysis patients at the fistula and non-fistula arm were analysed. Slope parameters and the areas under the curve of characteristic sections of pulse waves as well as the power spectrum of the pulse waves and their first and second derivatives were computed. Furthermore, the amplitude of volumetric change (AMP) was assessed. Duplex sonography served as a reference method. RESULTS: In the comprehensive set of novel pulse wave parameters significant inter-arm differences were demonstrated and a significant delay of the systolic maximum at the fistula arm in comparison to the non-fistula arm (204 ± 3.4 vs. 162 ± 5.3 ms, p < 0.001) was proven. Unexpectedly, pulse wave velocity apparently did not differ between both arms (7.85 vs. 8.05 m/s at the fistula/non-fistula side, p = 0.942). The inter-arm differences of the slope parameters were more pronounced in forearm than in upper arm fistulas. Finally, we showed that the inter-arm difference of AMP correlated with volume flow (r = 0.326 with p = 0.017). CONCLUSION: Pulse waves as assessed by oscillometric pulse wave analysis have distinct features at fistula and non-fistula arms. This is due to enhanced arteriovenous flow, i.e. in both the brachial artery and the fistula vein. The analysis of those alterations has the potential to assess fistula function.

Estimated pulse wave velocity as a forefront indicator of developing metabolic syndrome in Korean adults.

BACKGROUND/AIMS: The predictive value of the estimated pulse wave velocity (ePWV) for the development of metabolic syndrome has not yet been extensively explored. This study aimed to fill this gap by evaluating ePWV as a potential predictor of metabolic syndrome development in middle-aged Korean adults. METHODS: Using prospective data obtained from the Ansan-Ansung cohort database, participants without metabolic syndrome at baseline were studied. ePWV was calculated using specific equations based on age and blood pressure. The primary outcome was the incidence of metabolic syndrome during a median follow-up period of 187 months. RESULTS: Among the 6,186 participants, 2,726 (44.1%) developed metabolic syndrome during the follow-up period. ePWV methvalues were categorized into tertiles to assess their predictive value for the development of metabolic syndrome. An ePWV cut-off of 7.407 m/s was identified as a predictor of metabolic syndrome development, with a sensitivity of 0.743 and a specificity of 0.464. Participants exceeding this cut-off, especially those in the third tertile (8.77-14.63 m/s), had a notably higher risk of developing metabolic syndrome. Specifically, the third tertile exhibited a 52.8% cumulative incidence compared with 30.8% in the first tertile. After adjustments, those in the third tertile faced a 1.530-fold increased risk of metabolic syndrome (95% confidence interval, 1.330-1.761). CONCLUSION: ePWV is a significant predictor of the development of metabolic syndrome. This finding underscores the potential of ePWV as a cardiometabolic risk assessment tool and can thus provide useful information for primary prevention strategies.

Assessing pressure wave components for aortic stiffness monitoring through spectral regression learning.

Aims: The ageing process notably induces structural changes in the arterial system, primarily manifesting as increased aortic stiffness, a precursor to cardiovascular events. While wave separation analysis is a robust tool for decomposing the components of blood pressure waveform, its relationship with cardiovascular events, such as aortic stiffening, is incompletely understood. Furthermore, its applicability has been limited due to the need for concurrent measurements of pressure and flow. Our aim in this study addresses this gap by introducing a spectral regression learning method for pressure-only wave separation analysis. Methods and results: Leveraging data from the Framingham Heart Study (2640 individuals, 55% women), we evaluate the accuracy of pressure-only estimates, their interchangeability with a reference method based on ultrasound-derived flow waves, and their association with carotid-femoral pulse wave velocity (PWV). Method-derived estimates are strongly correlated with the reference ones for forward wave amplitude ( R 2 = 0.91 ), backward wave amplitude ( R 2 = 0.88 ), and reflection index ( R 2 = 0.87 ) and moderately correlated with a time delay between forward and backward waves ( R 2 = 0.38 ). The proposed pressure-only method shows interchangeability with the reference method through covariate analysis. Adjusting for age, sex, body size, mean blood pressure, and heart rate, the results suggest that both pressure-only and pressure-flow evaluations of wave separation parameters yield similar model performances for predicting carotid-femoral PWV, with forward wave amplitude being the only significant factor (P < 0.001; 95% confidence interval, 0.056-0.097). Conclusion: We propose an interchangeable pressure-only wave separation analysis method and demonstrate its clinical applicability in capturing aortic stiffening. The proposed method provides a valuable non-invasive tool for assessing cardiovascular health.

Arterial Stiffness and Heart Failure With Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) is prevalent and associated with a poor prognosis, imposing a significant burden on society. Arterial stiffness is increasingly recognized as a crucial factor in the pathophysiology of HFpEF, affecting diagnosis, management, and prognosis. As a hallmark of vascular aging, arterial stiffness contributes to increased afterload on the left ventricle (LV), leading to diastolic dysfunction, a key feature of HFpEF. Elevated arterial stiffness is linked with common cardiovascular risk factors in HFpEF, such as hypertension, diabetes and obesity, exacerbating the progression of disease. Studies have demonstrated that patients with HFpEF exhibit significantly higher levels of arterial stiffness compared to those without HFpEF, highlighting the value of arterial stiffness measurements as both diagnostic and prognostic tools. Moreover, interventions aimed at reducing arterial stiffness, whether through pharmacological therapies or lifestyle modifications, have shown potential in improving LV diastolic function and patient outcomes. Despite these advancements, the precise mechanisms by which arterial stiffness contributes to HFpEF are still not fully understood, necessitating the need for further research.

Development of a Personalized Multiclass Classification Model to Detect Blood Pressure Variations Associated with Physical or Cognitive Workload.

Comprehending the regulatory mechanisms influencing blood pressure control is pivotal for continuous monitoring of this parameter. Implementing a personalized machine learning model, utilizing data-driven features, presents an opportunity to facilitate tracking blood pressure fluctuations in various conditions. In this work, data-driven photoplethysmograph features extracted from the brachial and digital arteries of 28 healthy subjects were used to feed a random forest classifier in an attempt to develop a system capable of tracking blood pressure. We evaluated the behavior of this latter classifier according to the different sizes of the training set and degrees of personalization used. Aggregated accuracy, precision, recall, and F1-score were equal to 95.1%, 95.2%, 95%, and 95.4% when 30% of a target subject's pulse waveforms were combined with five randomly selected source subjects available in the dataset. Experimental findings illustrated that incorporating a pre-training stage with data from different subjects made it viable to discern morphological distinctions in beat-to-beat pulse waveforms under conditions of cognitive or physical workload.

Make my haemodynamic monitor GREEN: sustainable monitoring solutions.

Anaesthesiologists overwhelmingly favour pulse wave analysis techniques as their primary method to monitor cardiac output during high-risk noncardiac surgery. In patients with a radial arterial catheter in place, pulse wave analysis techniques have the advantage of instantly providing non-operator-dependent and continuous haemodynamic monitoring information. Green pulse wave analysis techniques working with any standard pressure transducer are as reliable as techniques requiring dedicated pressure transducers. They have the advantage of minimising plastic waste and related carbon dioxide emissions, and also significantly reducing hospital costs. The future integration of pulse wave analysis algorithms into multivariable bedside monitors, obviating the need for standalone haemodynamic monitors, could lead to wider use of haemodynamic monitoring solutions by further reducing their cost and carbon footprint.

Implications of pulse wave velocity and central pulse pressure in heart failure with reduced ejection fraction.

BACKGROUND: Carotid-femoral pulse wave velocity (cfPWV) and central pulse pressure (PP) are recognised as significant indicators of vascular health and predictors of cardiovascular outcomes. In this study, associations between central hemodynamics and left ventricular (LV) echocardiographic parameters were investigated in subjects with heart failure with reduced ejection fraction (HFrEF), comparing the results to healthy individuals. METHODS AND RESULTS: This cross-sectional prospective controlled study included 50 subjects with HFrEF [mean LV ejection fraction (EF) 26 ± 6.5%] and 30 healthy controls (mean LVEF 65.9 ± 5.3%). Pulse wave analysis (PWA) and carotid-femoral pulse wave velocity (cfPWV) were used to measure central hemodynamics and arterial stiffness. The HFrEF group displayed higher cfPWV (8.2 vs. 7.2 m/s, p = 0.007) and lower central (111.3 vs. 121.7 mmHg, p = 0.001) and peripheral (120.1 vs. 131.5 mmHg, p = 0.002) systolic blood pressure. Central pulse pressure (PP) was comparable between the two groups (37.6 vs. 40.4 mmHg, p = 0.169). In the HFrEF group, cfPWV significantly correlated with left ventricular end-diastolic volume (LVEDV) index (mL/m2) and LVEF, with LVEDV index being a significant independent predictor of cfPWV (R2 = 0.42, p = 0.003). Central PP was significantly associated with heart rate, LVEF and LVEDV index, with the latter being a significant independent predictor of central PP (R2 = 0.41, p < 0.001). These correlations were not observed in healthy controls. CONCLUSIONS: Significant associations between central hemodynamic measures and LV echocardiographic parameters were identified, suggesting the potential to use PWA and cfPWV as possible tools for managing HFrEF.

What is the context?Heart failure with reduced ejection fraction (HFrEF) affects millions of people worldwide.Vascular health plays a significant role in the development and progression of HFrEF.This study investigates two indicators of arterial stiffness­pulse wave velocity (PWV) and central pulse pressure (PP)­and their impact on the functioning of the heart in HFrEF patients compared to healthy individuals.What is new?The study found that higher carotid-femoral PWV and central PP, which typically indicate worse vascular health, were associated with better heart function in HFrEF patients. This paradoxical finding suggests that in the context of HFrEF, traditional markers of vascular health may have different implications.The study included non-invasive methods to evaluate these indicators, offering a potential new additional approach for monitoring and managing HFrEF.What is the impact?We could possibly use non-invasively evaluated PWV and central PP (measures of vascular function) as markers of left ventricular function assessment in HFrEF.

Influence of Blood Pressure Reduction on Pulse Wave Velocity in Primary Hypertension: A Meta-Analysis and Comparison With an Acute Modulation of Transmural Pressure.

BACKGROUND: Increased arterial stiffness and pulse wave velocity (PWV) of the aorta and large arteries impose adverse hemodynamic effects on the heart and other organs. Antihypertensive treatment reduces PWV, but it is unknown whether this results from an unloading of stiffer elements in the arterial wall or is due to an alternate functional or structural change that might differ according to class of antihypertensive drug. METHODS: We performed a systematic review and meta-analysis of the effects of different antihypertensive drug classes and duration of treatment on PWV with and without adjustment for change in mean arterial blood pressure (BP; study 1) and compared this to the change in PWV after an acute change in transmural pressure, simulating an acute change in BP (study 2). RESULTS: A total of 83 studies involving 6200 subjects were identified. For all drug classes combined, the reduction of PWV was 0.65 (95% CI, 0.46-0.83) m/s per 10 mm Hg reduction in mean arterial BP, a change similar to that induced by an acute change in transmural pressure in a group of hypertensive subjects. When adjusted for change in mean arterial BP, the reduction in PWV after treatment with beta-blockers or diuretics was less than that after treatment with angiotensin-converting enzyme inhibitors/angiotensin receptor antagonists or calcium channel antagonists. CONCLUSIONS: Reduction in PWV after antihypertensive treatment is largely explained by the reduction in BP, but there are some BP-independent effects. These might increase over time and contribute to better outcomes over the long term, but this remains to be demonstrated in long-term clinical trials.

Aortic pulse wave analysis and functional capacity of heart transplantation candidates: a pilot study.

We compared cardiovascular parameters obtained with the Mobil-O-Graph and functional capacity assessed by the Duke Activity Status Index (DASI) before and after Heart Transplantation (HT) and also compared the cardiovascular parameters and the functional capacity of candidates for HT with a control group. Peripheral and central vascular pressures increased after surgery. Similar results were observed in cardiac output and pulse wave velocity. The significant increase in left ventricular ejection fraction (LVEF) postoperatively was not followed by an increase in the functional capacity. 24 candidates for HT and 24 controls were also compared. Functional capacity was significantly lower in the HT candidates compared to controls. Stroke volume, systolic, diastolic, and pulse pressure measured peripherally and centrally were lower in the HT candidates when compared to controls. Despite the significant increase in peripheral and central blood pressures after surgery, the patients were normotensive. The 143.85% increase in LVEF in the postoperative period was not able to positively affect functional capacity. Furthermore, the lower values of LVEF, systolic volume, central and peripheral arterial pressures in the candidates for HT are consistent with the characteristics signs of advanced heart failure, negatively impacting functional capacity, as observed by the lower DASI score.

Impact of respiratory cycle during mechanical ventilation on beat-to-beat right ventricle stroke volume estimation by pulmonary artery pulse wave analysis.

BACKGROUND: The same principle behind pulse wave analysis can be applied on the pulmonary artery (PA) pressure waveform to estimate right ventricle stroke volume (RVSV). However, the PA pressure waveform might be influenced by the direct transmission of the intrathoracic pressure changes throughout the respiratory cycle caused by mechanical ventilation (MV), potentially impacting the reliability of PA pulse wave analysis (PAPWA). We assessed a new method that minimizes the direct effect of the MV on continuous PA pressure measurements and enhances the reliability of PAPWA in tracking beat-to-beat RVSV. METHODS: Continuous PA pressure and flow were simultaneously measured for 2-3 min in 5 pigs using a high-fidelity micro-tip catheter and a transonic flow sensor around the PA trunk, both pre and post an experimental ARDS model. RVSV was estimated by PAPWA indexes such as pulse pressure (SVPP), systolic area (SVSystAUC) and standard deviation (SVSD) beat-to-beat from both corrected and non-corrected PA signals. The reference RVSV was derived from the PA flow signal (SVref). RESULTS: The reliability of PAPWA in tracking RVSV on a beat-to-beat basis was enhanced after accounting for the direct impact of intrathoracic pressure changes induced by MV throughout the respiratory cycle. This was evidenced by an increase in the correlation between SVref and RVSV estimated by PAPWA under healthy conditions: rho between SVref and non-corrected SVSD - 0.111 (0.342), corrected SVSD 0.876 (0.130), non-corrected SVSystAUC 0.543 (0.141) and corrected SVSystAUC 0.923 (0.050). Following ARDS, correlations were SVref and non-corrected SVSD - 0.033 (0.262), corrected SVSD 0.839 (0.077), non-corrected SVSystAUC 0.483 (0.114) and corrected SVSystAUC 0.928 (0.026). Correction also led to reduced limits of agreement between SVref and SVSD and SVSystAUC in the two evaluated conditions. CONCLUSIONS: In our experimental model, we confirmed that correcting for mechanical ventilation induced changes during the respiratory cycle improves the performance of PAPWA for beat-to-beat estimation of RVSV compared to uncorrected measurements. This was demonstrated by a better correlation and agreement between the actual SV and the obtained from PAPWA.

A reliable evaluation approach for multichannel signal denoising algorithms based on a novel arterial pulse acquisition system.

Background: Tactile sensors are utilized to measure multichannel pulse signals in pulse wave analysis (PWA). Owing to noise interferences, researchers have applied various denoising algorithms on multichannel pulse signals. To comprehensively assess these algorithms, numerous evaluation metrics have been proposed. However, these studies did not investigate the noise mechanisms in depth and lacked reference pulse signals, thus making the evaluations insufficiently objective. Materials and methods: An applicable denoising evaluation approach for multichannel pulse signal algorithms based on an arterial pulse acquisition system is established by superimposing real-world multichannel noise to the reference signals. The system, comprising a SphygmoCor and a uniaxial noise acquisition device, allows us to acquire single-reference pulse signals as well as real-world multichannel noise. Results: We assess eight popular denoising algorithms with three evaluation metrics, including amplitude relative error (ARE), mean square error (MSE) and increased percentage signal-noise ratio (SNR%). Our proposed approach provides accurate and objective evaluations of multichannel pulse signal denoising. Notably, classic algorithms for single-channel denoising are not recommended for multichannel denoising. Comparatively, RPCA-based algorithms can denoise pulse signals independently for each channel. Conclusion: This study sets the stage for the establishment of accurate and objective pulse signal denoising evaluations and provides insights for data-driven clinical diagnoses in cardiovascular medicine.

Exploring the Influence of Insulin Resistance on Arterial Stiffness in Healthy Adults: From the Metabolic and Cardiovascular Health Insights of the EVasCu Study.

Previous evidence associates insulin resistance with arterial stiffness in various pathologies, yet limited reports exist in healthy adults. Therefore, this study aims to estimate the association between insulin resistance and arterial stiffness in healthy adults. The cross-sectional EVasCu study enrolled 390 participants (42.05 ± 13.15 years). ANCOVAs, unadjusted (model 1) and adjusted (model 2), explored the association between arterial stiffness markers (aortic Pulse Wave Velocity [aPWV], Augmentation Index [AIx@75] and Cardio-Ankle Vascular Index [CAVI]), and insulin resistance markers (Homeostasis Model Assessment of Insulin Resistance [HOMA-IR], Quantitative Insulin Sensitivity Check Index [QUICKI] and Triglycerides-Glucose [TyG]). In model 1, all insulin resistance markers were associated with aPWV, HOMA-IR and QUICKI were associated with AIx@75, and the TyG index was associated with CAVI. In model 2, HOMA-IR and QUICKI increased aPWV by 0.179 and 0.156 m/s (p = 0.001 and p = 0.011), and AIx@75 by 4.17 and 5.39% (p = 0.009 and p = 0.003). The EVasCu study offers valuable insights into the relationship between insulin resistance and arterial stiffness in healthy adults, providing a deeper understanding of metabolic and cardiovascular health. By examining this influence, we embark on an intriguing exploration of how these factors interplay in the human body.

Assessment of Arterial Stiffness and Biochemical Markers in Systemic Lupus Erythematosus in the Diagnosis of Subclinical Atherosclerosis.

Patients with systemic lupus erythematosus (SLE) are 2-10 times more likely to develop cardiovascular disease (CVD) than the general population. The assessment of the risk of developing CVD is an important direction for further clinical management. The study was conducted retrospectively and included patients with SLE. The aim of the study was to assess the measurements of pulse wave velocity (PWV), carotid intima-media thickness (CIMT), ankle-brachial index (ABI) and biochemical parameters. Subclinical atherosclerosis was also assessed. The study included 98 patients with SLE with an age- and sex-matched control group of 68 healthy adults. Statistical significance was found in the SLE group and the controls for N-terminal fragment of pro-B-type natriuretic peptide (NT proBNP) (144.87 vs. 36.41 pg/mL, p = 0.0018), high-sensitivity cardiac troponin (hs-cTn) (25.43 vs. 6.38 ng/L, p = 0.0303) and D-Dimer levels (0.73 vs. 0.36 µg/mL, p = 0.0088), left CIMT (1.03 vs. 0.62 mm, p < 0.0001), right CIMT (0.93 vs. 0.63 mm, p < 0.0001) and PWV CF (9.74 vs. 7.98 m/s, p = 0.0294). A positive correlation was found between NT proBNP and PWV CF (r = 0.6880, p = 0.0498) and hs-cTn and PVW carotid-femoral (CF) (r = 0.8862, p = 0.0499) in SLE. A positive correlation was reported between PWV CF and systolic blood pressure (r = 0.5025, p = 0.0487). The measurement of carotid-femoral PWV is a simple, non-invasive, and reproducible method and may independently predict future CVD events and their cause. Further studies are warranted to establish the prognostic value of PWV in patients with SLE, as it may be superior to CIMT measurements in the early stages of vascular disorders.

Estimation of aortic stiffness by finger photoplethysmography using enhanced pulse wave analysis and machine learning.

Introduction: Aortic stiffness plays a critical role in the evolution of cardiovascular diseases, but the assessment requires specialized equipment. Photoplethysmography (PPG) and single-lead electrocardiogram (ECG) are readily available in healthcare and wearable devices. We studied whether a brief PPG registration, alone or in combination with single-lead ECG, could be used to reliably estimate aortic stiffness. Methods: A proof-of-concept study with simultaneous high-resolution index finger recordings of infrared PPG, single-lead ECG, and finger blood pressure (Finapres) was performed in 33 participants [median age 44 (range 21-66) years, 19 men] and repeated within 2 weeks. Carotid-femoral pulse wave velocity (cfPWV; two-site tonometry with SphygmoCor) was used as a reference. A brachial single-cuff oscillometric device assessed aortic pulse wave velocity (aoPWV; Arteriograph) for further comparisons. We extracted 136 established PPG waveform features and engineered 13 new with improved coupling to the finger blood pressure curve. Height-normalized pulse arrival time (NPAT) was derived using ECG. Machine learning methods were used to develop prediction models. Results: The best PPG-based models predicted cfPWV and aoPWV well (root-mean-square errors of 0.70 and 0.52 m/s, respectively), with minor improvements by adding NPAT. Repeatability and agreement were on par with the reference equipment. A new PPG feature, an amplitude ratio from the early phase of the waveform, was most important in modelling, showing strong correlations with cfPWV and aoPWV (r = -0.81 and -0.75, respectively, both P < 0.001). Conclusion: Using new features and machine learning methods, a brief finger PPG registration can estimate aortic stiffness without requiring additional information on age, anthropometry, or blood pressure. Repeatability and agreement were comparable to those obtained using non-invasive reference equipment. Provided further validation, this readily available simple method could improve cardiovascular risk evaluation, treatment, and prognosis.