Blood pressure and its variability: classic and novel measurement techniques

Intermittent documentation of blood pressure values does not provide comprehensive evaluation of the hemodynamic response during continuous intravenous medication administration

Blood pressure (BP) is a dynamic measure that is frequently discussed in static terms. There exist many limitations in current documentation systems whereby documented BP values may not be reflective of the dynamic variability of BP. This study used an observational, prospective, non-randomized study design to examine the variability in BP response during intravenous vasoactive medication administration in an intensive care unit setting. Subjects admitted to a neuroscience intensive care unit were monitored continuously during a 12-hour period. The BP values include systolic BP, diastolic BP, and mean arterial pressure. Intermittent values from an intra-arterial figurecatheter (a-line) and continuously sampled values from an a-line obtained using continuous data acquisition (CDA) software, were compared to intermittently sampling of cuff-based BP measurements documented in the medical record. The 30 patients provided 1,220,511 BP observations from CDA, 944 from a-line documentation, and 416 from cuff-based BP documentation. The systolic BP was used as a goal parameter for 23 (77%) of the patients. Repeated measures models demonstrated that on average cuff-based differed from intermittent a-line and from CDA (p < .005) for all BP values. No differences between a-line and CDA were observed. Concordance correlation coefficients ranged from 0.56 to 0.72 for a-line, cuff-based BP, and CDA, indicating moderate agreement. Using intermittently documented BP values does not fully represent the dynamic nature of BP over time.

Validation of the A&D BP UA-1100NFC/UA-1100NFC-W, hoseless upper arm-type home blood pressure devices, according to the ISO81060-2:2018/Amd 1:2020 protocol

The aim of this study was to validate the performance of the A&D UA-1100NFC hoseless devices of two cuff sizes in monitoring blood pressure (BP) in the upper arm according to the International Organization for Standardization (ISO) 81060-2:2018/amendment (Amd) 1:2020 protocol. The accuracy of the UA-1100NFC (for arm circumferences of 22.0-32.0 cm) and the UA-1100NFC-W (for arm circumferences of 22.0-42.0 cm) was assessed using the same-arm sequence protocol as per the ISO 81060-2:2018/Amd 1:2020 standard. Individuals aged >12 years were recruited from the outpatients and volunteers of Jichi Medical University (Tochigi, Japan); 85 participants were included in the final analyses for each device. Both devices performed well against the standard; mean and SD values for the differences between the device-measured and observer-measured SBP and DBP values met both criterion 1 and criterion 2 of the standard [(UA-1100NFC) criterion 1: -3.71 ± 6.82 mmHg and 0.86 ± 6.33 mmHg, respectively; criterion 2: 5.65 mmHg and 5.87 mmHg, respectively; (UA-1100NFC-W) criterion 1: 0.73 ± 7.84 mmHg and 1.72 ± 6.44 mmHg, respectively; criterion 2: 6.49 mmHg and 5.86 mmHg, respectively]. The Bland-Altman plots did not show any systematic variation in the error. Both the UA-1100NFC and UA-1100NFC-W hoseless devices had a high level of accuracy and fulfilled the requirements of the ISO81060-2:2018/Amd 1:2020 validation standard. They are therefore suitable as home BP monitoring tools in patients with hypertension.

Non-Contact Optical Blood Pressure Biometry Using AI-Based Analysis of Non-Mydriatic Fundus Imaging

Background

This study was developed to determine whether a machine learning model could be developed to assess blood pressure with accuracy comparable to arm cuff measurements.

Methods

A deep learning model was developed based on the UK Biobank dataset and was trained to detect both systolic and diastolic pressure. The hypothesis was formulated after data collection and before the development of the model. Comparison was conducted between arm cuff measurements, as ground truth, and results from the model, using Mean Absolute Error, Mean Squared Error, and Coefficient of Determination (R^2).

Results

Systolic pressure was measured with 9.81 Mean Absolute Error, 165.13 Mean Squared Error and 0.36 R^2. Diastolic pressure was measured with 6.00 Mean Absolute Error, 58.21 and 0.30 R^2.

Conclusions

This model improves on existing research and shows errors comparable to the variability of hand cuff measurements. The use of fundus images to assess blood pressure may be more indicative of long-term hypertension. Additional trials in clinical settings may be necessary, as well as additional prospective studies to validate results.

Blood pressure response to graded bicycle exercise in males and females across the age and fitness spectrum

AIMS

Blood pressure (BP) responses to exercise are frequently measured, with the concern that greater increases are a marker of disease. We sought to characterize the normal exercise BP response in healthy adults and its relationships with age, sex, and fitness.

METHODS AND RESULTS

Five hundred and eighty-nine participants [median age 46 (interquartile range 24-56) years, 81% male] underwent cardiopulmonary exercise testing with repeated, automated BP measures. An exaggerated maximal systolic BP (SBPmax) was defined from current guidelines as ≥210 mmHg in males and ≥190 mmHg in females. Individual linear regression analyses defined the relationship between BP and workload (W; SBP/W-slope and DBP/W-slope). Participants with or without an exaggerated SBPmax and above- or below-median SBP/W-slope were compared. An exaggerated SBPmax was found in 51% of males and 64% of females and was more prevalent in endurance-trained athletes (males 58%, females 72%, P < 0.001). The mean SBP/W-slope was lower in males (0.24 ± 0.10 mmHg/W) than females (0.27 ± 0.12 mmHg/W, P = 0.031). In both sexes, peak oxygen uptake (VO2peak) was inversely correlated with SBP/W-slope (P < 0.01). Those with an exaggerated SBPmax and below-median SBP/W-slope were 10 years younger and had a 20% higher VO2peak, on average (P < 0.001). A non-exaggerated SBPmax and above-median SBP/W-slope was observed in older individuals with the lowest VO2peak.

CONCLUSION

In a large cohort of healthy individuals, an exaggerated SBPmax was common and associated with higher fitness. In contrast, higher SBP indexed to W was associated with older age, lower fitness, and female sex. Thus, sex, age, and fitness should be considered when evaluating BP response to exercise.

REGISTRATION

Pro@Heart: NCT05164328, ACTRN12618000716268; ProAFHeart: ACTRN12618000711213; Master@Heart: NCT03711539.

Blood pressure variability and functional outcome after decompressive hemicraniectomy in malignant middle cerebral artery infarction

BACKGROUND AND PURPOSE

Malignant middle cerebral artery infarction (MMI) is a severe condition with a high mortality rate. While decompressive hemicraniectomy has been demonstrated to reduce mortality, there is limited knowledge regarding blood pressure (BP) management following the surgery. This study aimed to investigate whether early blood pressure variability after surgery is associated with functional outcomes.

METHODS

This study was a retrospective cohort analysis of patients with MMI who underwent decompressive hemicraniectomy. We calculated BP variability (BPV) by measuring BP hourly over a 72-h period following surgery. We investigated the association between BPV parameters and functional outcomes at 3-month. Additionally, we analyzed which specific time intervals within the 72 h post-surgery BPV were associated with functional outcomes.

RESULTS

A total of 110 patients were eligible for analysis. The mean age was 63.1 ± 13.1 years, and 57 (51.8%) were men. Among the systolic BPV parameters, the coefficient of variance showed a significant association with functional outcomes at 3-month (adjusted odds ratio [AOR]: 0.82, 95% CI: 0.69-0.95), and this association remained significant after adjusting for the antihypertensive agents use (AOR: 0.82, 95% CI: 0.70-0.95). In contrast, diastolic BPV parameters did not show a significant association with functional outcomes. Systolic BPV during the 0- to 24-h period of the 72-h observation was significantly associated with functional outcomes (AOR: 0.87, 95% CI: 0.76-0.98).

CONCLUSION

Our study identified a significant association between systolic BPV and 3-month functional outcomes in MMI patients who underwent decompressive hemicraniectomy. This association persisted regardless of the use of antihypertensive agents, particularly during the hyperacute phase within the first 24 h post-surgery.

The Constrained Disorder Principle Overcomes the Challenges of Methods for Assessing Uncertainty in Biological Systems

Different disciplines are developing various methods for determining and dealing with uncertainties in complex systems. The constrained disorder principle (CDP) accounts for the randomness, variability, and uncertainty that characterize biological systems and are essential for their proper function. Per the CDP, intrinsic unpredictability is mandatory for the dynamicity of biological systems under continuously changing internal and external perturbations. The present paper describes some of the parameters and challenges associated with uncertainty and randomness in biological systems and presents methods for quantifying them. Modeling biological systems necessitates accounting for the randomness, variability, and underlying uncertainty of systems in health and disease. The CDP provides a scheme for dealing with uncertainty in biological systems and sets the basis for using them. This paper presents the CDP-based second-generation artificial intelligence system that incorporates variability to improve the effectiveness of medical interventions. It describes the use of the digital pill that comprises algorithm-based personalized treatment regimens regulated by closed-loop systems based on personalized signatures of variability. The CDP provides a method for using uncertainties in complex systems in an outcome-based manner.

AI-driven system for non-contact continuous nocturnal blood pressure monitoring using fiber optic ballistocardiography

Continuous monitoring of nocturnal blood pressure is crucial for hypertension management and cardiovascular risk assessment. However, current clinical methods are invasive and discomforting, posing challenges. These traditional techniques often disrupt sleep, impacting patient compliance and measurement accuracy. Here we introduce a non-contact system for continuous monitoring of nocturnal blood pressure, utilizing ballistocardiogram signals. The key component of this system is the utilization of advanced, flexible fiber optic sensors designed to capture medical-grade ballistocardiogram signals accurately. Our artificial intelligence model extracts deep learning and fiducial features with physical meanings and implements an efficient, lightweight personalization scheme on the edge device. Furthermore, the system incorporates a crucial algorithm to automatically detect the user's sleeping posture, ensuring accurate measurement of nocturnal blood pressure. The model underwent rigorous evaluation using open-source and self-collected datasets comprising 158 subjects, demonstrating its effectiveness across various blood pressure ranges, demographic groups, and sleep states. This innovative system, suitable for real-world unconstrained sleeping scenarios, allows for enhanced hypertension screening and management and provides new insights for clinical research into cardiovascular complications.

Minimum number of readings necessary for determining long-term visit-to-visit blood pressure variability to predict cardiovascular outcomes in people with diabetes

BACKGROUND

People with diabetes often have increased blood pressure (BP) variability because of autonomic dysfunction and arterial stiffness, making it a critical factor in predicting clinical outcomes. We investigated the reproducibility of long-term visit-to-visit BP variability (VVV) and the minimum number of BP readings to reliably determine VVV in people with diabetes.

METHODS

This multicenter retrospective study used data from electronic health records of the Korea University Medical Center database. Altogether, 10 475 people with diabetes who had more than nine BP readings during a maximum period of 2 years were identified. This study focused on the coefficient of variation of these readings and their correlation with major adverse cardiovascular events (MACE) over a 3-year follow-up period.

RESULTS

The mean age of the participants was 65.2 years. Of these, 53.2% were men, and 87.4% had hypertension. The mean coefficient of variation of multiple SBP readings that best predicted the 3-year MACE were 8.4, 9.5, 9.0, 9.0, and 9.7 for three, five, seven, nine, and all readings, respectively. Patients with high VVV (coefficient of variation of five SBP readings >9) exhibited a higher incidence of 3-year MACE (10.1%) than those with low VVV (5.4%, P < 0.001). In the multivariable analysis, high VVV of both SBP and DBP were independently associated with 3-year MACE.

CONCLUSION

Long-term VVV in the BP is a reproducible and reliable predictor of cardiovascular outcomes in people with diabetes. A minimum of five BP measurements are recommended for effective intraindividual VVV estimation and cardiovascular risk assessment.

Comparison of visit-to-visit blood pressure variability and time in target range in predicting risk for cognitive outcomes in the SPRINT trial

BACKGROUND

Blood pressure (BP) variability (BPV) and time in target range (TTR) are emerging vascular risk factors for dementia, independent of traditionally targeted mean BP.

OBJECTIVE

Determine whether BPV or TTR is most strongly associated with cognitive risk.

METHODS

In this post hoc analysis of the SPRINT trial, 8034 participants underwent repeated BP measurement and cognitive testing at baseline and follow-up. Visit-to-visit BPV was calculated as average real variability. TTR was the percent of time in desired treatment arm target range (standard: 120-140 mmHg systolic BP; intensive: 110-130 mmHg systolic BP). Adjudicated clinical outcomes were no cognitive impairment, mild cognitive impairment (MCI), and probable dementia. We investigated a direct comparison of BPV and TTR in predicting cognitive risk, stratified by BP treatment group.

RESULTS

Elevated BPV was associated with increased risk for MCI (adjusted HR: 1.21 [95% CI 1.10, 1.33], p < 0.001) and MCI/dementia (HR: 1.17 [95% CI 1.07, 1.27], p < 0.001) in the standard group, and dementia (HR: 1.17 [95% CI 1.01, 1.36], p = 0.039) in the intensive group. Higher TTR was related to lower dementia risk (HR: 0.72 [95% CI 0.60, 0.86], p < 0.001) in the intensive group only.

CONCLUSIONS

Visit-to-visit BPV outperformed TTR in predicting risk for MCI and MCI/dementia. TTR was more strongly associated with dementia risk under intensive treatment. Findings were independent of mean BP in a cohort with rigorously controlled BP and suggest newer aspects of BP control may be harnessed to further reduce cognitive risk.

CLINICAL TRIAL INFORMATION

ClinicalTrials.gov; NCT01206062.

Integrating AI-driven wearable devices and biometric data into stroke risk assessment: A review of opportunities and challenges

Stroke is a leading cause of morbidity and mortality worldwide, and early detection of risk factors is critical for prevention and improved outcomes. Traditional stroke risk assessments, relying on sporadic clinical visits, fail to capture dynamic changes in risk factors such as hypertension and atrial fibrillation (AF). Wearable technology (devices), combined with biometric data analysis, offers a transformative approach by enabling continuous monitoring of physiological parameters. This narrative review was conducted using a systematic approach to identify and analyze peer-reviewed articles, reports, and case studies from reputable scientific databases. The search strategy focused on articles published between 2010 till date using pre-determined keywords. Relevant studies were selected based on their focus on wearable devices and AI-driven technologies in stroke prevention, diagnosis, and rehabilitation. The selected literature was categorized thematically to explore applications, opportunities, challenges, and future directions. The review explores the current landscape of wearable devices in stroke risk assessment, focusing on their role in early detection, personalized care, and integration into clinical practice. The review highlights the opportunities presented by continuous monitoring and predictive analytics, where AI-driven algorithms can analyze biometric data to provide tailored interventions. Personalized stroke risk assessments, powered by machine learning, enable dynamic and individualized care plans. Furthermore, the integration of wearable technology with telemedicine facilitates remote patient monitoring and rehabilitation, particularly in underserved areas. Despite these advances, challenges remain. Issues such as data accuracy, privacy concerns, and the integration of wearables into healthcare systems must be addressed to fully realize their potential. As wearable technology evolves, its application in stroke care could revolutionize prevention, diagnosis, and rehabilitation, improving patient outcomes and reducing the global burden of stroke.

Higher intraindividual variability of body mass index is associated with elevated risk of COVID-19 related hospitalization and post-COVID conditions

BACKGROUND

Cardiometabolic diseases are risk factors for COVID-19 severity. The extent that cardiometabolic health represents a modifiable factor to mitigate the short- and long-term consequences from SARS-CoV-2 remains unclear. Our objective was to evaluate the associations between intraindividual variability of cardiometabolic health indicators and COVID-19 related hospitalizations and post-COVID conditions (PCC) among a relatively healthy population.

METHODS

This retrospective, multi-site cohort study was a post-hoc analysis among individuals with cardiometabolic health data collected during routine blood donation visits in 24 US states (2009-2018) and who responded to COVID-19 questionnaires (2021-2023). Intraindividual variability of blood pressure (systolic, diastolic), total circulating cholesterol, and body mass index (BMI) were defined as the coefficient of variation (CV) across all available donation timepoints (ranging from 3 to 74); participants were categorized into CV quartiles. Associations were evaluated by multivariable binomial regressions.

RESULTS

Overall, 3344 participants provided 42,090 donations (median 9 [IQR 5, 17]). The median age was 48 years (38, 56) at the first study donation. 1.2% (N = 40) were hospitalized due to COVID-19 and 15.5% (N = 519) had PCC. Higher BMI variability was associated with greater risk of COVID-19 hospitalization (4th quartile aRR 4.15 [95% CI 1.31, 13.11], p = 0.02; 3rd quartile aRR 3.41 [95% CI 1.09, 10.69], p = 0.04). Participants with higher variability of BMI had greater risk of PCC (4th quartile aRR 1.29 [95% CI 1.02, 1.64]; p = 0.04). Intraindividual variability of blood pressure (systolic, diastolic) and total circulating cholesterol were not associated with COVID-19 hospitalization or PCC risk (all p > 0.05). From causal mediation analysis, the association between the highest quartiles of BMI variability and PCC was not mediated by hospitalization (p > 0.05).

CONCLUSIONS

Higher intraindividual variability of BMI was associated with COVID-19 hospitalization and PCC risk. Our findings underscore the need for further elucidating mechanisms that explain these associations and importance for consistent maintenance of body weight.

Assessment of blood pressure variability: characteristics and comparison of blood pressure measurement methods

Previous studies have reported that blood pressure variability (BPV) is associated with the risk of cardiovascular events independent of blood pressure (BP) levels. While there is little evidence from intervention trials examining whether suppressing BPV is useful in preventing cardiovascular disease, it is suggested that detection of abnormally elevated BPV may be useful in reducing cardiovascular events adding by complementing management of appropriate BP levels. Cuffless BP devices can assess beat-to-beat BPV. Although cuffless BP monitoring devices have measurement accuracy issues that need to be resolved, this is an area of research where the evidence is accumulating rapidly, with many publications on beat-to-beat BPV over several decades. Ambulatory BP monitoring (ABPM) can assess 24-hour BPV and nocturnal dipping patterns. Day-to-day BPV and visit-to-visit BPV are assessed by self-measured BP monitoring at home and office BP measurement, respectively. 24 h, day-to-day, and visit-to-visit BPV have been reported to be associated with cardiovascular prognosis. Although there have been several studies comparing whether ABPM and self-measured BP monitoring at home is the superior measurement method of BPV, no strong evidence has been accumulated that indicates whether ABPM or self-measured home BP is superior. ABPM and self-measured BP monitoring have their own advantages and complement each other in the assessment of BPV.

The Role of Wearable Devices in Blood Pressure Monitoring and Hypertension Management: A Systematic Review

Hypertension constitutes a significant risk factor for the development of many coronary artery diseases. In recent years, the advancement of technology and artificial intelligence has led to significant research and breakthroughs in wearable devices that can monitor blood pressure (BP). These devices offer continuous, real-time BP readings, facilitating the early detection and prevention of hypertension. Detailed research was conducted via the PubMed and Scopus databases, using the following keywords: Wearable devices AND Hypertension AND Monitoring. The research was made in the articles from 2017 and subsequently. The aim of the present review is to highlight the benefits of advanced wearable devices, such as smartwatches equipped with BP tracking, inflatable cuffs, finger and wrist monitors, as well as patch and skin-compatible sensors, which provide individuals with the possibility of detecting BP at any time, while also preventing hypertension disease. Finally, wearable devices develop a telehealth connection between patient and physician. However, they ought to be adhered to by particular protocols that attest to their accuracy.

Telemedicine in nephrology: future perspective and solutions

Telemedicine is a medical practice that uses electronic information and communication technologies. It is not exclusive to face-to-face care but complements face-to-face care and other forms of medical care. It has advantages such as facilitating home therapy, reducing patient travel time and costs, and empowering patients. This makes equitable access to care feasible. Clinical studies have been conducted on telemedicine in nephrology outpatient care, inpatient consultations and hemodialysis, indicating that telemedicine can improve patient satisfaction, leading to enhanced treatment owing to increased adherence and frequency of visits. However, it has not been sufficiently used in the kidney field. The key to spreading "telenephrology" (telemedicine in nephrology) is how physical examinations and laboratory/imaging/physiological tests, currently challenging to perform without face-to-face contact, can be substituted with methods optimized for the telemedicine framework. This paper describes the current status of telemedicine and telenephrology, along with advanced methods for collecting data equivalent to laboratory, imaging and physiological tests outside of hospitals, including estimation of serum creatinine levels from saliva or tear fluid, estimation of blood hemoglobin levels by taking pictures of the eyelid conjunctiva or nails with a smartphone and ultrasound of the kidneys using motion capture technology. With an understanding of the strengths and weaknesses of current telemedicine, we should make full use of it for better treatment and patient care. However, further telenephrology research is required.

Free Will as Defined by the Constrained Disorder Principle: a Restricted, Mandatory, Personalized, Regulated Process for Decision-Making

The concept of free will has challenged physicists, biologists, philosophers, and other professionals for decades. The constrained disorder principle (CDP) is a fundamental law that defines systems according to their inherent variability. It provides mechanisms for adapting to dynamic environments. This work examines the CDP's perspective of free will concerning various free will theories. Per the CDP, systems lack intentions, and the "freedom" to select and act is built into their design. The "freedom" is embedded within the response range determined by the boundaries of the systems' variability. This built-in and self-generating mechanism enables systems to cope with perturbations. According to the CDP, neither dualism nor an unknown metaphysical apparatus dictates choices. Brain variability facilitates cognitive adaptation to complex, unpredictable situations across various environments. Human behaviors and decisions reflect an underlying physical variability in the brain and other organs for dealing with unpredictable noises. Choices are not predetermined but reflect the ongoing adaptation processes to dynamic prssu½res. Malfunctions and disease states are characterized by inappropriate variability, reflecting an inability to respond adequately to perturbations. Incorporating CDP-based interventions can overcome malfunctions and disease states and improve decision processes. CDP-based second-generation artificial intelligence platforms improve interventions and are being evaluated to augment personal development, wellness, and health.

Blood pressure variability associated with falls in nursing home residents

BACKGROUND

High variations in serially measured blood pressures (BPs) portend a variety of adverse clinical events including dementia, cardiovascular sequelae and frailty. In this study, systolic blood pressure variability (BPV) was examined for its association with fall frequency and time to next fall among older adults living in nursing homes.

METHODS

BP values and falls over time were extracted from medical records of nursing home residents aged ≥65 years over a 10-month period. BPV was measured as the standard deviation of 17 to 20 systolic values, and its correlation with falls and time to next fall were evaluated according to quartile values.

RESULTS

One hundred patient charts were analyzed with nearly 2000 BP data points. All older adults had at least one fall incident. Higher BPV was related to more falls, shorter time between the first and second fall and fewer average days between falls. Subgroups of high BP and different diagnoses affected this association between BPV and falls.

CONCLUSIONS

People who fall often show a high variability in BP; as the number of falls increases, the BPV also increases. This study suggests that BPV may be marker for patients who might benefit from more aggressive application of fall reduction strategies. Geriatr Gerontol Int 2024; 24: 1315-1319.

Novel metrics for tracking blood pressure changes incontinuous cuffless blood pressure estimations

Recent studies revealed the importance of tracking continuous blood pressure (BP) changes in monitoring and controlling hypertension and diagnosing cardiovascular diseases. However, current evaluation protocols utilize distance measures as primary metrics, which cannot properly evaluate the ability of the estimation model to track BP changes. This paper proposes a comprehensive evaluation framework which evaluates the distance and trend similarity metrics, and the composite metric of both between the reference and estimated BPs. The results of applying both widely used conventional metrics and the new proposed metrics for BP estimations are demonstrated in an example of comparing the reference with a set of different BP estimations. Then, the metrics are applied to BP estimations obtained using state-of-the-art (SOTA) algorithms. It is shown that even though SOTA algorithms have a low mean and standard deviation of absolute difference, they are not capable of tracking short-term blood pressure changes. Additionally, the proposed metrics are normalized metrics and range from -1 to 1, making them intuitively interpretable, similar to well-known correlation coefficients. Therefore, we suggest that the proposed evaluation framework should be used regularly in evaluating continuous BP monitoring systems.

The Co-Piloting Model for Using Artificial Intelligence Systems in Medicine: Implementing the Constrained-Disorder-Principle-Based Second-Generation System

The development of artificial intelligence (AI) and machine learning (ML)-based systems in medicine is growing, and these systems are being used for disease diagnosis, drug development, and treatment personalization. Some of these systems are designed to perform activities that demand human cognitive function. However, use of these systems in routine care by patients and caregivers lags behind expectations. This paper reviews several challenges that healthcare systems face and the obstacles of integrating digital systems into routine care. This paper focuses on integrating digital systems with human physicians. It describes second-generation AI systems designed to move closer to biology and reduce complexity, augmenting but not replacing physicians to improve patient outcomes. The constrained disorder principle (CDP) defines complex biological systems by their degree of regulated variability. This paper describes the CDP-based second-generation AI platform, which is the basis for the Digital Pill that is humanizing AI by moving closer to human biology via using the inherent variability of biological systems for improving outcomes. This system augments physicians, assisting them in decision-making to improve patients' responses and adherence but not replacing healthcare providers. It restores the efficacy of chronic drugs and improves adherence while generating data-driven therapeutic regimens. While AI can substitute for many medical activities, it is unlikely to replace human physicians. Human doctors will continue serving patients with capabilities augmented by AI. The described co-piloting model better reflects biological pathways and provides assistance to physicians for better care.

Innovations in blood pressure measurement and reporting technology: International Society of Hypertension position paper endorsed by the World Hypertension League, European Society of Hypertension, Asian Pacific Society of Hypertension, and Latin American Society of Hypertension

Blood pressure (BP) is a key contributor to the lifetime risk of preclinical organ damage and cardiovascular disease. Traditional clinic-based BP readings are typically measured infrequently and under standardized/resting conditions and therefore do not capture BP values during normal everyday activity. Therefore, current hypertension guidelines emphasize the importance of incorporating out-of-office BP measurement into strategies for hypertension diagnosis and management. However, conventional home and ambulatory BP monitoring devices use the upper-arm cuff oscillometric method and only provide intermittent BP readings under static conditions or in a limited number of situations. New innovations include technologies for BP estimation based on processing of sensor signals supported by artificial intelligence tools, technologies for remote monitoring, reporting and storage of BP data, and technologies for BP data interpretation and patient interaction designed to improve hypertension management ("digital therapeutics"). The number and volume of data relating to new devices/technologies is increasing rapidly and will continue to grow. This International Society of Hypertension position paper describes the new devices/technologies, presents evidence relating to new BP measurement techniques and related indices, highlights standard for the validation of new devices/technologies, discusses the reliability and utility of novel BP monitoring devices, the association of these metrics with clinical outcomes, and the use of digital therapeutics. It also highlights the challenges and evidence gaps that need to be overcome before these new technologies can be considered as a user-friendly and accurate source of novel BP data to inform clinical hypertension management strategies.

Blood pressure variability compromises vascular function in middle-aged mice

Blood pressure variability (BPV) has emerged as a novel risk factor for cognitive decline and dementia, independent of alterations in average blood pressure (BP). However, the underlying consequences of large BP fluctuations on the neurovascular complex are unknown. We developed a novel mouse model of BPV in middle-aged mice based on intermittent Angiotensin II infusions. Using radio telemetry, we demonstrated that the 24-hr BP averages of these mice were similar to controls, indicating BPV without hypertension. Chronic (20-25 days) BPV led to a blunted bradycardic response and cognitive deficits. Two-photon imaging of parenchymal arterioles showed enhanced pressure-evoked constrictions (myogenic response) in BPV mice. Sensory stimulus-evoked dilations (neurovascular coupling) were greater at higher BP levels in control mice, but this pressure-dependence was lost in BPV mice. Our findings support the notion that large BP variations impair vascular function at the neurovascular complex and contribute to cognitive decline.

Using the Constrained Disorder Principle to Navigate Uncertainties in Biology and Medicine: Refining Fuzzy Algorithms

Uncertainty in biology refers to situations in which information is imperfect or unknown. Variability, on the other hand, is measured by the frequency distribution of observed data. Biological variability adds to the uncertainty. The Constrained Disorder Principle (CDP) defines all systems in the universe by their inherent variability. According to the CDP, systems exhibit a degree of variability necessary for their proper function, allowing them to adapt to changes in their environments. Per the CDP, while variability differs from uncertainty, it can be viewed as a regulated mechanism for efficient functionality rather than uncertainty. This paper explores the various aspects of un-certainties in biology. It focuses on using CDP-based platforms for refining fuzzy algorithms to address some of the challenges associated with biological and medical uncertainties. Developing a fuzzy decision tree that considers the natural variability of systems can help minimize uncertainty. This method can reveal previously unidentified classes, reduce the number of unknowns, improve the accuracy of modeling results, and generate algorithm outputs that are more biologically and clinically relevant.

Harnessing Variability Signatures and Biological Noise May Enhance Immunotherapies' Efficacy and Act as Novel Biomarkers for Diagnosing and Monitoring Immune-Associated Disorders

Lack of response to immunotherapies poses a significant challenge in treating immune-mediated disorders and cancers. While the mechanisms associated with poor responsiveness are not well defined and change between and among subjects, the current methods for overcoming the loss of response are insufficient. The Constrained Disorder Principle (CDP) explains biological systems based on their inherent variability, bounded by dynamic boundaries that change in response to internal and external perturbations. Inter and intra-subject variability characterize the immune system, making it difficult to provide a single therapeutic regimen to all patients and even the same patients over time. The dynamicity of the immune variability is also a significant challenge for personalizing immunotherapies. The CDP-based second-generation artificial intelligence system is an outcome-based dynamic platform that incorporates personalized variability signatures into the therapeutic regimen and may provide methods for improving the response and overcoming the loss of response to treatments. The signatures of immune variability may also offer a method for identifying new biomarkers for early diagnosis, monitoring immune-related disorders, and evaluating the response to treatments.

A reconfigurable and conformal liquid sensor for ambulatory cardiac monitoring

The severe mismatch between solid bioelectronics and dynamic biological tissues has posed enduring challenges in the biomonitoring community. Here, we developed a reconfigurable liquid cardiac sensor capable of adapting to dynamic biological tissues, facilitating ambulatory cardiac monitoring unhindered by motion artifacts or interference from other biological activities. We employed an ultrahigh-resolution 3D scanning technique to capture tomographic images of the skin on the wrist. Then, we established a theoretical model to gain a deep understanding of the intricate interaction between our reconfigurable sensor and dynamic biological tissues. To properly elucidate the advantages of this sensor, we conducted cardiac monitoring alongside benchmarks such as the electrocardiogram. The liquid cardiac sensor was demonstrated to produce stable signals of high quality (23.1 dB) in ambulatory settings.

Smart solutions in hypertension diagnosis and management: a deep dive into artificial intelligence and modern wearables for blood pressure monitoring

Hypertension, a widespread cardiovascular issue, presents a major global health challenge. Traditional diagnosis and treatment methods involve periodic blood pressure monitoring and prescribing antihypertensive drugs. Smart technology integration in healthcare offers promising results in optimizing the diagnosis and treatment of various conditions. We investigate its role in improving hypertension diagnosis and treatment effectiveness using machine learning algorithms for early and accurate detection. Intelligent models trained on diverse datasets (encompassing physiological parameters, lifestyle factors, and genetic information) to detect subtle hypertension risk patterns. Adaptive algorithms analyze patient-specific data, optimizing treatment plans based on medication responses and lifestyle habits. This personalized approach ensures effective, minimally invasive interventions tailored to each patient. Wearables and smart sensors provide real-time health insights for proactive treatment adjustments and early complication detection.

Multimodal data-driven, vertical visualization prediction model for early prediction of atherosclerotic cardiovascular disease in patients with new-onset hypertension

BACKGROUND

: Hypertension is an important contributing factor to atherosclerotic cardiovascular disease (ASCVD), and multiple risk factors, many of which are implicated in metabolic disorders, contribute to the cause of hypertension. Despite the promise of multimodal data-driven prediction model, no such prediction model was available to predict the risk of ASCVD in Chinese individuals with new-onset hypertension and no history of ASCVD.

METHODS

: A total of 514 patients were randomly allocated to training and verification cohorts (ratio, 7 : 3). We employed Boruta feature selection and conducted multivariate Cox regression analyses to identify variables associated with ASCVD in these patients, which were subsequently utilized for constructing the predictive model. The performance of prediction model was assessed in terms of discriminatory power (C-index), calibration (calibration curves), and clinical utility [decision curve analysis (DCA)].

RESULTS

: This model was derived from four clinical variables: 24-h SBP coefficient of variation, 24-h DBP coefficient of variation, urea nitrogen and the triglyceride-glucose (TyG) index. Bootstrapping with 500 iterations was conducted to adjust the C-indexes were C-index = 0.731, 95% confidence interval (CI) 0.620-0.794 and C-index: 0.799, 95% CI 0.677-0.892 in the training and verification cohorts, respectively. Calibration plots with 500 bootstrapping iterations exhibited a strong correlation between the predicted and observed occurrences of ASCVD in both the training and verification cohorts. DCA analysis confirmed the clinical utility of this prediction model. The constructed nomogram demonstrated significant additional prognostic utility for ASCVD, as evidenced by improvements in the C-index, net reclassification improvement, integrated discrimination improvement, and DCA compared with the overall ASCVD risk assessment.

CONCLUSION

The developed longitudinal prediction model based on multimodal data can effectively predict ASCVD risk in individuals with an initial diagnosis of hypertension.

TRIAL REGISTRATION

: The trial was registered in the Chinese Clinical Trial Registry (ChiCTR2300074392).

Very short-term blood pressure variability by pulse transit time-based measurements during night-time predicts future cardiovascular events in patients with ischemic heart disease

Blood pressure (BP) variability (BPV) is associated with an increased risk of cardiovascular events, independent of absolute BP values. However, the predictive significance of very short-term BPV, occurring within seconds or minutes, in patients with ischemic heart disease (IHD) has yet to be established. This prospective study involved 206 consecutive hospitalized patients with IHD (mean age 67.6 years, 78.2% male) who underwent pulse transit time (PTT)-based continuous BP recording during the night-time. Very short-term BPV was assessed by standard deviation (SD), coefficient of variation (CV), and variation independent of mean (VIM) of PTT-BP. Clinical outcome data were collected. When the patients were categorized into two groups according to the median value of very short-term BPV, Kaplan-Meier analysis revealed that patients with elevated SD, CV, and VIM of systolic and diastolic PTT-BP were associated with lower event-free survival rates from the composite cardiovascular events including cardiac deaths, worsening heart failure cases, nonfatal myocardial infarctions, unplanned revascularizations, and strokes over a median follow-up of 797 days. In a multivariate Cox proportional hazards analysis adjusting for confounding variables, each parameter as a continuous variable was independently associated with adverse events. Incorporating very short-term BPV into basic models had a significant impact on risk reclassification and integrated discrimination for cardiovascular outcomes. In conclusion, the identification of patients with elevated very short-term BPV during the night-time through a PTT-driven approach helps stratify the future risk in IHD patients.

Artificial intelligence-enhanced patient evaluation: bridging art and science

The advent of digital health and artificial intelligence (AI) has promised to revolutionize clinical care, but real-world patient evaluation has yet to witness transformative changes. As history taking and physical examination continue to rely on long-established practices, a growing pipeline of AI-enhanced digital tools may soon augment the traditional clinical encounter into a data-driven process. This article presents an evidence-backed vision of how promising AI applications may enhance traditional practices, streamlining tedious tasks while elevating diverse data sources, including AI-enabled stethoscopes, cameras, and wearable sensors, to platforms for personalized medicine and efficient care delivery. Through the lens of traditional patient evaluation, we illustrate how digital technologies may soon be interwoven into routine clinical workflows, introducing a novel paradigm of longitudinal monitoring. Finally, we provide a skeptic's view on the practical, ethical, and regulatory challenges that limit the uptake of such technologies.

A Cross-Sectional Survey of Fixed-Dose Combination Antihypertensive Medicine Prescribing in Twenty-Four Countries, Including Qualitative Insights

Background

Treatment inertia, non-adherence and non-persistence to medical treatment contribute to poor blood pressure (BP) control worldwide. Fixed dose combination (FDC) antihypertensive medicines simplify prescribing patterns and improve adherence. The aim of this study was to identify factors associated with prescribing FDC antihypertensive medicines and to understand if these factors differ among doctors worldwide.

Methods

A cross-sectional survey was conducted online from June 2023 to January 2024 to recruit doctors. We collaborated with an international network of researchers and clinicians identified through institutional connections. A passive snowballing recruitment strategy was employed, where network members forwarded the survey link to their clinical colleagues. The survey instrument, developed through a literature review, interviews with academic and clinical researchers, and pilot testing, assessed participants perspectives on prescribing FDC antihypertensive medicines for hypertension. Participants rated their level of agreement (5-point Likert scale) with statements representing six barriers and four facilitators to FDC use.

Findings

Data from 191 surveys were available for analysis. 25% (n = 47) of participants worked in high-income countries, 38% (n = 73) in upper-middle income, 25% (n = 48) in lower-middle income, 6% (n = 10) in low-income countries. Forty percent (n = 70) of participants were between 36-45 years of age; two thirds were male. Cost was reported as a barrier to prescribing FDC antihypertensive medicines [51% (n = 87) agreeing or strongly agreeing], followed by doctors' confidence in BP measured in clinic [40%, (n = 70)], access [37%, (n = 67)], appointment duration [35%, (n = 61)], concerns about side-effects [(21%, n = 37)], and non-adherence [12%, (n = 21)]. Facilitators to FDC antihypertensive polypills prescribing were clinician facing, such as access to educational supports [79%, (n = 143)], more BP measurement data [67%, (n = 120)], a clinical nudge in health records [61%, (n = 109)] and patient-facing including improved patient health literacy [49%, (n = 88)]. The levels of agreement and strong agreement across all barriers and facilitators were similar for participants working in higher or lower income countries. Across all countries, participants rated FDC antihypertensive medications highly valuable for managing patients with non-adherence, (82% reported high or very high value), for patients with high pill burden (80%).

Interpretation

Cost and access were the most common barriers to prescribing FDCs across high- and low-income countries. While greater educational support for clinicians was perceived as the leading potential facilitator of FDC use, this seems unlikely to be effective without addressing access.

Sleep Apnea, Autonomic Disturbances, and Blood Pressure Variability

Augmented blood pressure variability has emerged as a quantity predictive of adverse cardiovascular outcomes. Among the range of intrinsic and extrinsic factors shown to increase night-time, circadian, short-term, and long-term blood pressure variations, the presence and severity of obstructive sleep apnea have emerged as one of the most prevalent and potent. Obstructive sleep apnea alters acutely the normal nocturnal equilibrium between sympathetic and parasympathetic tone, magnifying nocturnal blood pressure oscillations, and induces sustained autonomic aftereffects with the capacity to amplify short-term and intersessional blood pressure variabilities. The object of this brief review is to synthesize the current understanding of the potential interrelations between obstructive sleep apnea, the acute and sustained autonomic disturbances that it elicits, and beat-to-beat blood pressure fluctuation during sleep, nocturnal dipping status, and day-to-day blood pressure variability and the consequences of these perturbations for cardiovascular risk.

Blood pressure time at target and its prognostic value for cardiovascular outcomes: a scoping review

The proportion of time that blood pressure (BP) readings are at treatment target levels, commonly referred to as time at target or time in therapeutic range (BP-TTR), is emerging as a useful measure for evaluating hypertension management effectiveness and assessing longitudinal BP control. However, method of determination for BP-TTR differs across studies. This review identifies variations in BP-TTR determination methodologies and its potential prognostic value for cardiovascular outcomes. Following PRISMA extension for scoping reviews guidelines, literature was systematically searched in Embase, PubMed, Scopus, Web of Science, and CINAHL. Relevant clinical trials, observational studies, cohort studies, cross-sectional studies, and systematic reviews published in English were screened. Of 369 articles identified, 17 articles were included. Studies differed in the BP targets used (e.g., BP < 140/90 mmHg or 130/80 mmHg; systolic BP within 110-130 mmHg or 120-140 mmHg), BP-TTR measurement duration (range 24 h to 15 years), and calculation method (linear interpolation method, n = 12 [71%]; proportion of BP readings at target, n = 5 [29%]). Regardless of method, studies consistently demonstrated that higher BP-TTR was associated with reduced risk of cardiovascular outcomes. Six of eight studies found the association was independent of mean achieved BP or last measured BP. Despite variation in methods of BP-TTR determination, these studies demonstrated the potential prognostic value of BP-TTR for cardiovascular outcomes beyond current BP control measures. We recommend standardization of BP-TTR methodology, with preference for linear interpolation method when BP measurements are few or less frequent, and proportion of BP readings method when large number of BP readings are available.

Wearable cuffless blood pressure tracking: when will they be good enough?

Wearable health monitoring is a multibillion-dollar industry. But the holy grail is probably getting it right for blood pressure monitoring without a cuff, because raised blood pressure is very common and the leading cause of death in the world. Many have tried and failed, but industry is persisting: numerous cuffless wearable blood pressure devices are on the market, several technologies have been developed, hundreds of patents are registered every year, and some devices already have regulatory approval. However, to convince the die-hard blood pressure critic is a different ball game. To understand the challenges of currently accepted methods and cuffless devices, I performed a 24-h blood pressure monitoring self-test, including measurements when awake, asleep and watching an intense match of the Rugby World Cup final, with the purpose to demonstrate the challenges and opportunities we face. Blood pressure was monitored using five different devices simultaneously: validated left and right arm cuff blood pressure, and three cuffless wearable devices (wrist-band, chest patch and a ring). Whilst none of these devices proved to be perfect in capturing a physiologically challenging measure, namely blood pressure, it emphasised that our current practice of a single blood pressure measurement in clinical practice should be revisited. It further begs the question of when cuffless measurements will be good enough to incorporate in clinical decision-making.

Reliability of beat-to-beat blood pressure variability in older adults

Blood pressure variability (BPV) is emerging as an important risk factor across numerous disease states, including cerebrovascular and neurodegenerative disease in older adults. However, there is no current consensus regarding specific use cases for the numerous available BPV metrics. There is also little published data supporting the ability to reliably measure BPV across metrics in older adults. The present study derived BPV metrics from continuous beat-to-beat blood pressure monitoring data. Two sequential 7 min waveforms were analyzed. Absolute and relative reliability testing was performed. Differences between antihypertensive medication users and non-users on BPV metric reliability was also assessed. All sequence and dispersion based BPV metrics displayed good test-retest reliability. A measure of BP instability displayed only moderate reliability. Systolic and diastolic average real variability displayed the highest levels of reliability at ICC = 0.87 and 0.82 respectively. Additionally, systolic average real variability was the most reliable metric in both the antihypertensive use group, and the no antihypertensive use group. In conclusion, beat-to-beat dispersion and sequence-based metrics of BPV can be reliably obtained in older adults using noninvasive continuous blood pressure monitoring. Average real variability may be the most reliable and specific beat-to-beat blood pressure variability metric due to its decreased susceptibility to outliers and low frequency blood pressure oscillations.

Short-Term Blood Pressure Variability among Young Adults at High or Low Risk for Depression

Background: Depression has been shown to have adverse effects on blood pressure (BP) and is associated with high blood pressure variability (BPV). In turn, high short-term BPV has been related to eventual cardiovascular risk. But it is not clear how early in adulthood the detrimental effects of depression on BPV may be discerned, if being at high risk for depression also compromises BPV, and whether the clinical features of depression moderate its adverse effects. We investigated these three issues among young adults using an office-like setting. Methods: In total, 218 subjects with a history of childhood-onset major depressive episodes (probands), 206 never-depressed full biological siblings of the probands (high-risk siblings), and 166 emotionally healthy unrelated controls received a psychiatric evaluation and three standardized-sitting BP measurements 5 min apart. Short-term BPV was defined as the maximum difference between measures (range) for each case. The statistical methods included analyses of variance/covariance, chi-square tests, and multiple regression. Results: Systolic and diastolic BP decreased over consecutive measurements (p < 0.001). After controlling for age, the probands, siblings, and controls did not differ significantly in terms of BPV. However, the number of lifetime depressive episodes did predict the diastolic BP range (p = 0.005): probands with the highest number of depressive episodes had the largest short-term diastolic BPV. Conclusions: On a group level, the adverse effects on BPV of having experienced or being at high risk for depression are not yet evident during young adulthood. However, the number of major depressive episodes, which is an index of lifetime depression burden, predicts higher BPV. Thus, BPV monitoring for young adults with clinical depression histories could be part of an early intervention program to reduce the risk of eventual cardiovascular disease.

Blood pressure variability assessed by office, home, and ambulatory measurements before and during antihypertensive drug treatment: a sub-analysis of the REVERENT randomized trial

OBJECTIVES

Blood pressure (BP) variability (BPV) can be assessed using office (OBP), home (HBP), or ambulatory BP (ABP) measurements. This analysis investigated the association and agreement between OBP, HBP, and ABP measurements for BPV assessment at baseline and 10 weeks after initiating antihypertensive drug therapy.

METHODS

Untreated hypertensive patients with elevated BPV were randomized to receive an angiotensin-converting enzyme inhibitor (ramipril) or a calcium channel blocker (nifedipine GITS) in a 10-week, open-label, blinded-end point study. BPV was assessed using standard deviation (SD) and coefficient of variation (CV) (reading-to-reading analyses).

RESULTS

Data from 146 participants from three research centers (Athens/Greece; Milan/Italy; Shanghai/China) were analyzed [mean age 53 ± 10 (SD) years, male individuals 60%, baseline systolic OBP, HBP, and 24 h ABP 144 ± 9, 138 ± 10, and 143 ± 10 mmHg, respectively]. Post-treatment minus pre-treatment systolic CV difference was: OBP: 0.3%, P  = 0.28; HBP: -0.2%, P  = 0.20; 24 h ABP: 1.1%, P  < 0.001. Home and ambulatory (not office) BPV indices presented weak-to-moderate correlation, both before and during treatment (range of coefficients 0.04-0.33). The correlation coefficient between systolic HBP and awake ABP CV was 0.21 and 0.28 before and during treatment, respectively ( P  < 0.05/< 0.001, respectively). Home and ambulatory (not office) BPV indices presented slight-to-fair agreement (range 64-73%) in detecting participants with high systolic BPV (top quartile of respective distributions) both before and during treatment (kappa range 0.04-0.27).

CONCLUSION

These data showed a weak-to-moderate association between out-of-office (but not office) BPV indices both before and during BP-lowering treatment, with reasonable agreement in detecting individuals with high BPV. Out-of-office BP measurements provide more similar and consistent BPV information than office measurements.

Empagliflozin combined with sacubitril/valsartan in hypertensive patients with heart failure: a retrospective study of efficacy and effect on blood pressure variability and cardiac function

OBJECTIVE

To evaluate the efficacy of empagliflozin combined with sacubitril/valsartan in treating hypertensive patients with heart failure (HF), focusing on its effects on blood pressure variability (BPV) and cardiac function.

METHODS

This retrospective study included 101 patients with hypertension and heart failure with reduced ejection fraction treated at Baoji High-Tech Hospital from October 2021 to October 2023. Patients were divided into two groups: an observation group (n=51), treated with both empagliflozin and sacubitril/valsartan, and a control group (n=50), treated with sacubitril/valsartan alone. We compared the therapeutic effects, BPV (including 24-hour, daytime, and nighttime systolic and diastolic BPV), cardiac function indicators, levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and cardiac troponin I (cTnI) before and after treatment, and the incidence of adverse reactions between the groups. Independent risk factors affecting treatment efficacy were also analyzed.

RESULTS

The total effective rate of treatment in the observation group was significantly higher than in the control group (P<0.05). Both groups showed reductions in daytime and nighttime systolic and diastolic BPV after treatment, with the observation group displaying more pronounced improvements (all P<0.05). Enhancements in cardiac ultrasound measurements, NT-proBNP levels, and cTnI levels were more significant in the observation group compared to the control group post-treatment (both P<0.05). There was no significant difference in the incidence of adverse reactions during treatment between the two groups (P>0.05). Age and comorbid diabetes were identified as independent risk factors for poor prognosis, while treatment with empagliflozin combined with sacubitril/valsartan was a protective factor.

CONCLUSION

Empagliflozin combined with sacubitril/valsartan significantly enhances treatment efficacy in hypertensive patients with heart failure, effectively improves cardiac function and BPV, and demonstrates good safety.

Recommendations for evaluating photoplethysmography-based algorithms for blood pressure assessment

Photoplethysmography (PPG) is a non-invasive optical technique that measures changes in blood volume in the microvascular tissue bed of the body. While it shows potential as a clinical tool for blood pressure (BP) assessment and hypertension management, several sources of error can affect its performance. One such source is the PPG-based algorithm, which can lead to measurement bias and inaccuracy. Here, we review seven widely used measures to assess PPG-based algorithm performance and recommend implementing standardized error evaluation steps in their development. This standardization can reduce bias and improve the reliability and accuracy of PPG-based BP estimation, leading to better health outcomes for patients managing hypertension.

Transforming Cardiovascular Care With Artificial Intelligence: From Discovery to Practice: JACC State-of-the-Art Review

Artificial intelligence (AI) has the potential to transform every facet of cardiovascular practice and research. The exponential rise in technology powered by AI is defining new frontiers in cardiovascular care, with innovations that span novel diagnostic modalities, new digital native biomarkers of disease, and high-performing tools evaluating care quality and prognosticating clinical outcomes. These digital innovations promise expanded access to cardiovascular screening and monitoring, especially among those without access to high-quality, specialized care historically. Moreover, AI is propelling biological and clinical discoveries that will make future cardiovascular care more personalized, precise, and effective. The review brings together these diverse AI innovations, highlighting developments in multimodal cardiovascular AI across clinical practice and biomedical discovery, and envisioning this new future backed by contemporary science and emerging discoveries. Finally, we define the critical path and the safeguards essential to realizing this AI-enabled future that helps achieve optimal cardiovascular health and outcomes for all.

Blood pressure and heart rate variability to assess autonomic response to an acute bout of high intensity interval exercise in healthy young adults

Autonomic nervous system (ANS) activity causes acute variations in blood pressure (BP) and heart rate (HR). These systems are challenged during high intensity interval exercise (HIIE). However, BP variability (BPV) and HR variability (HRV) response to HIIE is unknown. We characterized BPV and HRV during an acute HIIE bout using spectral low frequency [LF] and high frequency [HF] domains. We hypothesized that BPV would increase and HRV would decrease during high-intensity and active-recovery of HIIE compared to baseline [BL] and BPV would reduce and HRV would increase during cool down, post-HIIE, and 30 min post-HIIE compared to BL. HIIE involved 10 min of alternating high-intensity and active-recovery (approximately 70% and 10% of Wattmax) on a recumbent stepper. We did a secondary analysis on 23 datasets. The participants were 25 ± 1.5 years, 48% females. Our results showed high-intensity BPV LF was not significantly different from BL while HF increased. HRV LF and HF decreased compared to BL. During active-recovery, LF and HF for BPV and HRV increased greater than high-intensity. HRV LF and HF returned to BL after 30 min of recovery, whereas BPV HF was higher compared to BL. The rapid switching during HIIE uniquely modulates cardiovascular and ANS.

The impact of sphygmomanometer placement and cuff placement on blood pressure measurements

Background

Hypertension is the most significant global risk factor for mortality and morbidity, making standardized blood pressure measurement crucial.

Objectives

To investigate whether the location of blood pressure monitors and the positioning of cuffs yield differing results in blood pressure measurements.

Methods

Patients admitted to the Affiliated Hospital of Jiujiang College between 1 January 2022 and 30 June 2023 were enrolled in this study and randomly allocated into four groups. These groups were defined based on the positioning of monitoring equipment as follows: varied placements of cuffs on automatic blood pressure monitors, different heights for mercury column blood pressure monitors, varied heights for automatic blood pressure monitors, and different orientations for the cuff airbag tubes on electrocardiogram monitors. Blood pressure was measured and recorded for each group, followed by an analysis of the variations in readings across the different setups.

Results

In the first cohort of 763 individuals, mean systolic blood pressure measured at the standard upper arm site was 128.8 ± 10.5 mmHg, compared to 125.3 ± 10.4 mmHg at the elbow fossa. The corresponding diastolic pressures were 79.2 ± 10.7 and 75.0 ± 10.6 mmHg, respectively. The difference in systolic pressure between these positions was significant at 3.48 ± 3.22 mmHg (t₁ = 29.91, p₁ < 0.001) and for diastolic pressure at 4.23 ± 1.31 mmHg (t₂ = 88.98, p₂ < 0.001). For the subsequent groups, involving 253, 312, and 225 individuals, respectively, blood pressure measurements were analyzed and compared across different methods within each group. All p-values exceeded 0.05, indicating no statistically significant differences.

Conclusions

Blood pressure values measured at the elbow fossa position using an upper arm-type automatic sphygmomanometer were found to be lower than those measured at the upper arm position, with a difference of 3.48 mmHg for systolic and 4.23 mmHg for diastolic pressures. It is therefore essential to position the cuff correctly, specifically 2-3 cm above the elbow fossa, when utilizing an upper arm-type automatic sphygmomanometer for blood pressure monitoring. Conversely, the placement of the mercury column sphygmomanometer and the automated sphygmomanometer at varying heights had no significant effect on blood pressure readings. Similarly, the orientation of the electrocardiogram's cuffed balloon tube, whether facing upward or downward, did not influence blood pressure measurement outcomes.

Unravelling the Belgian cascade of hypertension care and its determinants: insights from a cross-sectional analysis

BACKGROUND

Hypertension is a major risk factor for cardiovascular disease and all-cause mortality worldwide. Despite the widespread availability of effective antihypertensives, blood pressure (BP) control rates remain suboptimal, even in high-income countries such as Belgium. In this study, we used a cascade of care approach to identify where most patients are lost along the continuum of hypertension care in Belgium, and to assess the main risk factors for attrition at various stages of hypertension management.

METHODS

Using cross-sectional data from the 2018 Belgian Health Interview Survey and the Belgian Health Examination Survey, we estimated hypertension prevalence among the Belgian population aged 40-79 years, and the proportion that was (1) screened, (2) diagnosed, (3) linked to care, (4) in treatment, (5) followed up and (6) well-controlled. Cox regression models were estimated to identify individual risk factors for being unlinked to hypertension care, untreated and not followed up appropriately.

RESULTS

The prevalence of hypertension based on self-reported and measured high BP was 43.3%. While 98% of the hypertensive population had their BP measured in the past 5 years, only 56.7% were diagnosed. Furthermore, 53.4% were linked to care, 49.8% were in treatment and 43.4% received adequate follow-up. Less than a quarter (23.5%) achieved BP control. Among those diagnosed with hypertension, males, those of younger age, without comorbidities, and smokers, were more likely to be unlinked to care. Once in care, younger age, lower BMI, financial hardship, and psychological distress were associated with a higher risk of being untreated. Finally, among those treated for hypertension, females, those of younger age, and without comorbidities were more likely to receive no adequate follow-up.

CONCLUSION

Our results show that undiagnosed hypertension is the most significant barrier to BP control in Belgium. Health interventions are thus needed to improve the accurate and timely diagnosis of hypertension. Once diagnosed, the Belgian health system retains patients fairly well along the continuum of hypertension care, yet targeted health interventions to improve hypertension management for high-risk groups remain necessary, especially with regard to improving treatment rates.

Exercise blood pressure, cardiorespiratory fitness, fatness and cardiovascular risk in children and adolescents

Cardiovascular disease remains the leading cause of mortality on a global scale. Individuals who possess risk factors for cardiovascular disease, such as high blood pressure (BP) and obesity, face an elevated risk of experiencing organ-specific pathophysiological changes. This damage includes pathophysiological changes in the heart and peripheral vascular systems, such as ventricular hypertrophy, arterial stiffening, and vascular narrowing and stenosis. Consequently, these damages are associated with an increased risk of developing severe cardiovascular outcomes including stroke, myocardial infarction, heart failure, and coronary heart disease. Among all the risk factors associated with cardiovascular disease, high blood pressure emerges as the most prominent. However, conventional resting BP measurement methods such as auscultatory or oscillometric methods may fail to identify many individuals with asymptomatic high BP. Recently, exercise BP has emerged as a valuable diagnostic tool for identifying real (high) blood pressure levels and assessing underlying cardiovascular risk, in addition to resting BP measurements in adults. Furthermore, numerous established factors, such as low cardiorespiratory fitness and high body fatness, have been confirmed to contribute to exercise BP and the associated cardiovascular risk. Modifying these factors may help reduce high exercise BP and, consequently, alleviate the burden of cardiovascular disease. A significant body of evidence has demonstrated cardiovascular disease in later life have their origins in early life. Children and adolescents with these cardiovascular risk factors also possess a greater propensity to develop cardiovascular diseases later in life. Nevertheless, the majority of previous studies on the clinical utility of exercise BP have been conducted in middle-to-older aged populations, often with pre-existing clinical conditions. Therefore, there is a need to investigate further of the factors influencing exercise BP in adolescence and its association with cardiovascular risk in early life. Our previously published work showed that exercise BP is a potential useful method to detect adolescents with increased cardiovascular risk. Children and adolescents with cardiovascular risk factors are more likely to develop cardiovascular diseases later in life. However, previous studies on the clinical utility of exercise BP have largely focused on middle-to-older aged populations with pre-existing clinical conditions. Therefore, there is a need to investigate further the factors influencing exercise BP in adolescence and its association with future cardiovascular risk. Our previous studies, which focused on exercise BP measured at submaximal intensity, have shown that exercise BP is a potentially useful method for identifying adolescents at increased cardiovascular risk. Our previous findings suggest that improving cardio-respiratory fitness and reducing body fatness may help to reduce the risk of developing cardiovascular disease and improve overall cardiovascular health. These findings have important implications for the development of effective prevention and early detection strategies, which can contribute to improved public health outcomes.

Combined effect of time in target range and variability of systolic blood pressure on cardiovascular outcomes and mortality in patients with hypertension: A prospective cohort study

Time in target range (TTR) and blood pressure variability (BPV) of systolic blood pressure (SBP) are independent risk factors for major adverse cardiovascular events (MACE) and all-cause mortality in hypertensive patients. However, the association of the combination of low TTR and high BPV of SBP with the risk of MACE and all-cause mortality is unclear. This study sought to investigate the combined effect of the TTR and BPV on the risk of MACE and all-cause mortality in patients with hypertension. A total of 11 496 hypertensive patients from the Kailuan cohort study were included in our study. All participants were divided into four groups according to their TTR and BPV levels. Cox proportional hazards regression models were used to calculate the hazard ratios (HRs) and 95% confidence interval (CI) for incident MACE and all-cause mortality. During a median follow-up of 5.64 years, 839 MACEs (included 99 cases of myocardial infarction, 591 cases of stroke, and 191 cases of heart failure) and 621 deaths occurred. Compared with the high-TTR and low-BPV group, the HRs (95% CI) of MACE and all-cause mortality were 1.309 (1.025-1.671) and 1.842 (1.373-2.473) for the high-TTR and high-BPV group, 1.692 (1.347-2.125) and 1.731 (1.298-2.309) for the low-TTR & low-BPV group, 2.132 (1.728-2.629) and 2.247 (1.722-2.932) for the low-TTR & high-BPV group. Our study suggests that the combination of low TTR and high BPV of SBP was associated with a higher risk of MACE and all-cause mortality in patients with hypertension.

Abnormal blood pressure dipping pattern: frequency, determinants, and correlates in Diabetes Mellitus patients in the Cardiovascular Health Risk Assessment in Diabetes Mellitus (CHiD) study

Purpose

Non-dipping status is associated with increased total and cardiovascular mortality in many disease conditions including diabetes mellitus. The pattern and its implications are not well described among Africans. This study was done to describe the frequency of abnormal blood pressure (BP) dipping among T2DM subjects, its determinants and correlates in Ogbomoso, Nigeria.

Methods

This was a cross-sectional study done at the LAUTECH Teaching Hospital, Ogbomoso. One hundred individuals diagnosed with T2DM were recruited and they had 24-hour ambulatory BP monitoring, echocardiography, ECG, and carotid Doppler among other evaluations. Statistical analysis was done using SPSS 27.0 (Chicago Ill, USA).

Results

The mean age of the participants was 59.3 ± 10.8 years, mean body mass index 27.7 ± 5.9 kg/m2 with a mean duration of diabetes of 7.52 ± 5.54 years. Abnormal BP dipping was present in 89% (consisting of 41% or reverse dippers and 48% non-dippers). T2DM subjects with abnormal dipping pattern were more likely to be females, had higher glycated haemoglobin, lower fractional shortening, higher left atrial volume and left ventricular mass index, and a higher DM duration than those with normal BP dipping status. The major determinants of abnormal dipping pattern were the duration of diabetes and low HDL-C concentration.

Conclusion

Abnormal BP dipping pattern is highly prevalent in T2DM subjects, especially among females. Abnormal BP dipping was also associated with markers of increased cardiovascular risk such as impaired kidney function, left ventricular hypertrophy, postural hypotension, history of intermittent claudication, and presence of plaques on carotid Doppler studies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01337-8.

Systolic blood pressure visit-to-visit variability and outcomes in Asian patients with atrial fibrillation

We aimed to assess the association between SBP-VVV and outcomes in Asian patients with atrial fibrillation (AF). AF patients in the COOL-AF registry with SBP measured at baseline, and at least two other visits were studied. We defined SBP-VVV using the standard deviation (SD) of average SBP. Patients were categorized according to the quartiles of SBP SD. The associations between SBP-VVV and outcomes were assessed in the adjusted Cox model. We studied 3172 patients (mean age 67.7 years; 41.8% female), with the prevalence of hypertension being 69%. Warfarin was used in 69% of patients, whereas 7% received non-vitamin K antagonist oral anticoagulants. The minimum and maximum SD of average SBP in the study population was 0.58 and 56.38 mmHg respectively. The cutoff of SD of average SBP for each quartile in our study were 9.09, 12.15, and 16.21 mmHg. The rates of all-cause mortality, ischemic stroke or systemic embolization (SSE), major bleeding, and intracranial hemorrhage (ICH) were 3.10, 1.42, 2.09, and 0.64 per 100 person-years, respectively. Compared with the first quartile, patients in the fourth quartile had a significantly higher risk of mortality (adjusted HR 1.60, 95%CI 1.13-2.25), bleeding (aHR 1.92, 95%CI 1.25-2.96) and ICH (aHR 3.51, 95%CI 1.40-8.76). The risk of SSE was not significantly different among the quartiles. SBP-VVV had a significant impact on the long-term outcomes of Asian patients with AF, particularly mortality and bleeding. Adequate SBP control and maintaining SBP stability over time may improve outcomes for AF patients.

Prognostic Impact of Metabolic Syndrome and Steatotic Liver Disease in Hepatocellular Carcinoma Using Machine Learning Techniques

Metabolic dysfunction-associated steatotic liver disease (MASLD) currently represents the predominant cause of chronic liver disease and is closely linked to a significant increase in the risk of hepatocellular carcinoma (HCC), even in the absence of liver cirrhosis. In this retrospective multicenter study, machine learning (ML) methods were employed to investigate the relationship between metabolic profile and prognosis at diagnosis in a total of 219 HCC patients. The eXtreme Gradient Boosting (XGB) method demonstrated superiority in identifying mortality predictors in our patients. Etiology was the most determining prognostic factor followed by Barcelona Clinic Liver Cancer (BCLC) and Eastern Cooperative Oncology Group (ECOG) classifications. Variables related to the development of hepatic steatosis and metabolic syndrome, such as elevated levels of alkaline phosphatase (ALP), uric acid, obesity, alcohol consumption, and high blood pressure (HBP), had a significant impact on mortality prediction. This study underscores the importance of metabolic syndrome as a determining factor in the progression of HCC secondary to MASLD. The use of ML techniques provides an effective tool to improve risk stratification and individualized therapeutic management in these patients.

Novel Metric for Non-Invasive Beat-to-Beat Blood Pressure Measurements Demonstrates Physiological Blood Pressure Fluctuations during Pregnancy

Beat-to-beat (B2B) variability in biomedical signals has been shown to have high diagnostic power in the treatment of various cardiovascular and autonomic disorders. In recent years, new techniques and devices have been developed to enable non-invasive blood pressure (BP) measurements. In this work, we aim to establish the concept of two-dimensional signal warping, an approved method from ECG signal processing, for non-invasive continuous BP signals. To this end, we introduce a novel BP-specific beat annotation algorithm and a B2B-BP fluctuation (B2B-BPF) metric novel for BP measurements that considers the entire BP waveform. In addition to careful validation with synthetic data, we applied the generated analysis pipeline to non-invasive continuous BP signals of 44 healthy pregnant women (30.9 ± 5.7 years) between the 21st and 30th week of gestation (WOG). In line with established variability metrics, a significant increase (p < 0.05) in B2B-BPF can be observed with advancing WOGs. Our processing pipeline enables robust extraction of B2B-BPF, demonstrates the influence of various factors such as increasing WOG or exercise on blood pressure during pregnancy, and indicates the potential of novel non-invasive biosignal sensing techniques in diagnostics. The results represent B2B-BP changes in healthy pregnant women and allow for future comparison with those signals acquired from women with hypertensive disorders.