Publications

Wearable technologies have the potential to transform ambulatory and at-home hemodynamic monitoring by providing continuous assessments of cardiovascular health metrics and guiding clinical management. However, existing cuffless wearable devices for blood pressure (BP) monitoring often rely on methods lacking theoretical foundations, such as pulse wave analysis or pulse arrival time, making them vulnerable to physiological and experimental confounders that undermine their accuracy and clinical utility. Here, we developed a smartwatch device with real-time electrical bioimpedance (BioZ) sensing for cuffless hemodynamic monitoring. We elucidate the biophysical relationship between BioZ and BP via a multiscale analytical and computational modeling framework, and identify physiological, anatomical, and experimental parameters that influence the pulsatile BioZ signal at the wrist. A signal-tagged physics-informed neural network incorporating fluid dynamics principles enables calibration-free estimation of BP and radial and axial blood velocity. We successfully tested our approach with healthy individuals at rest and after physical activity including physical and autonomic challenges, and with patients with hypertension and cardiovascular disease in outpatient and intensive care settings. Our findings demonstrate the feasibility of BioZ technology for cuffless BP and blood velocity monitoring, addressing critical limitations of existing cuffless technologies.

Atherosclerotic renal artery stenosis (RAS) affects nearly 7% of adults over age 65 and is associated with increased cardiovascular and renal morbidity. Although early observational studies suggested benefit from renal artery stenting, subsequent randomized trials failed to show improvement in major clinical endpoints, contributing to substantial declines in procedural use. To characterize contemporary practice, we conducted a retrospective cohort study of Medicare beneficiaries older than 65 years who underwent renal artery stenting for atherosclerotic RAS between 2016 and 2020. Using Medicare claims data, we evaluated baseline characteristics, temporal utilization, and post-procedural outcomes, stratified by race, geographic region, and dual Medicare-Medicaid enrollment status. Among 19,130 patients, the mean age was 76.0 years (±6.4), 59.2% were female, and 90.3% were White; 84.2% had chronic kidney disease and 48.7% had heart failure. Procedural rates declined by 41.1% over the study period. Compared with White patients, Black patients had higher adjusted risks of hypertensive crisis hospitalization (aHR 1.45, 95% CI 1.24-1.70) and dialysis initiation (aHR 1.78, 95% CI 1.39-2.27); patients of Other races also had greater risk of dialysis initiation (aHR 1.98, 95% CI 1.50-2.63). Patients in the South experienced higher unadjusted cardiovascular event rates (50.0%) but similar adjusted mortality compared with those in the Northeast (aHR 1.09, 95% CI 0.98-1.21). Dual enrollment was associated with increased all-cause mortality (aHR 1.31, 95% CI 1.20-1.43). In conclusion, renal artery stenting rates continued to decline in recent years, and contemporary recipients constitute an older, comorbid population with substantial cardiovascular risk. Outcomes differed markedly by race, socioeconomic status, and geography, highlighting the need for improved risk stratification and prospective evaluation of stenting in high-risk cohorts.

Background: Circulating sphingolipids have been implicated in central nervous system degenerative disorders, but their relationship with peripheral neuropathy remains unclear. Objectives: To evaluate associations between plasma sphingolipid levels and subsequent loss of vibration and light pressure sensation in the lower limbs of older adults. Methods: Plasma concentrations of 11 ceramide (Cer) and sphingomyelin (SM) species were measured in stored samples from 4612 participants in the Cardiovascular Health Study. Vibration sensation was assessed 4-6 years later in 2208 individuals using tuning fork testing, and light pressure sensation was evaluated 11-13 years later in 815 participants using monofilament testing. Sensory impairment was graded on a 3-point scale, with higher scores indicating greater loss. Ordinal logistic regression models examined associations between a doubling of sphingolipid levels and sensory decline, with stratification by diabetes status. Results: In primary models, no sphingolipid species showed significant associations with sensory outcomes. However, after adjusting for inflammatory markers, higher SM-16 levels were linked to increased odds of vibration sensation loss (OR 2.08; 95% CI: 1.11-3.90), while higher SM-24 levels were associated with reduced odds (OR 0.68; 95% CI: 0.46-0.998). Significant interactions with diabetes status were observed for light pressure sensation: SM-14 was associated with increased odds of sensory loss in participants with incident diabetes (OR 5.22; 95% CI: 1.58-17.29), and Cer-18 was associated with increased odds in those with prevalent diabetes (OR 2.38; 95% CI: 1.18-4.78). Conclusions: Elevated levels of specific ceramide and sphingomyelin species may be predictive of future peripheral sensory loss in older adults, with diabetes status influencing these associations.

BACKGROUND: There is growing interest in understanding the link between early life exposures to ambient air pollution and childhood blood pressure; however, existing findings, largely from single site/cohort studies, are inconclusive.

METHODS: We examined the association between exposures to fine particulate matter (PM2.5) and nitrogen dioxide (NO2) and blood pressure measured at age 5-12 years in 4863 U.S. children from 20 pregnancy cohorts of the NIH ECHO cohort. Point-based residential exposures were derived from spatiotemporal models with a biweekly resolution and averaged over each trimester, the whole pregnancy, and child age 0-2 years. We converted systolic (SBP) and diastolic blood pressure (DBP) to age-, sex-, and height-specific percentiles and classified children with SBP and/or DBP ≥ 90th percentile as high blood pressure (HBP). Associations of PM2.5 (per 5-μ g/m3) or NO2 (per 10-ppb) exposures with blood pressure outcomes were estimated using linear and Poisson regressions adjusted for sociodemographic, lifestyle, temporal, and spatial confounders.

RESULTS: Across windows, mean PM2.5 ranged from 7.6 to 7.9 μ g/m3, and mean NO2 ranged was 8.1-8.8 ppb. We found positive associations of PM2.5 in the first trimester with SBP percentile (β: 1.92, 95 %CI: 0.02, 3.83) and risk of HBP (RR: 1.16, 95 %CI: 1.02, 1.33). Higher PM2.5 exposures averaged over pregnancy and age 0-2 years were also related to elevated SBP percentiles and a higher risk of HBP, but with lower precision. Contrary to our hypotheses, inverse associations of pregnancy average NO2 with both SBP (β: -2.42, 95 %CI: -4.70, -0.14) and DBP (β: -1.94, 95 %CI: -3.81, -0.08) percentiles were suggested.

CONCLUSION: Results reinforce the detrimental effects of PM2.5 on childhood cardiometabolic health, even at low exposure levels. Such findings can inform regulatory policy on acceptable air pollution levels and appropriate controls. The inverse association between prenatal NO2 and blood pressure was counterintuitive and warrants further investigation.

PURPOSE: Fear of cancer recurrence (FCR) is highly common and, if poorly managed, can be distressing and impairing. We developed a virtual, mind-body resiliency intervention for fear of cancer recurrence in survivorship (IN FOCUS), which was shown to be feasible and improved FCR post-intervention. This report aimed to describe coping processes associated with FCR and effects of IN FOCUS on coping over time.

METHOD: A single-blinded, 2-arm, randomized controlled trial was conducted from July 2021 to March 2022 comparing IN FOCUS (8 weekly, 90-minute, synchronous virtual group classes teaching cognitive behavioral techniques, relaxation training, meditation, adaptive health behaviors, and positive psychology skills) to usual care (synchronous virtual community group support referral) among cancer survivors with non-metastatic disease and clinically elevated FCR (FCR Inventory severity ≥16). Measures included coping styles (Brief COPE) and perceived coping skills (Measure of Current Status-Part A). Intent-to-treat analyses with separate general linear mixed models were used to identify group-by-time effects (Cohen's d; 0.5 a medium effect, 0.8 a large effect) from baseline through 2 months and 5 months.

RESULTS: Sixty-four survivors enrolled (age M = 52 years, time since completing primary cancer treatment M = 5 years). By 5 months, survivors randomized to IN FOCUS (vs usual care) demonstrated multiple effects on coping in the medium to large range. Compared to usual care, IN FOCUS increased problem-focused coping, such as using instrumental support (d = 0.60), planning (d = 0.60), positive reframing (d = 0.48), and active coping (d = 0.45). Similarly, IN FOCUS improved emotion-focused coping, specifically venting (d = 0.70), acceptance (d = 0.58), humor (d = 0.50), and religion (d = 0.48). IN FOCUS also enhanced survivors' coping confidence (d = 0.79), relaxation skills (d = 0.57), and assertiveness (d = 0.46). Avoidance-focused coping and awareness of physical tension exhibited less robust changes by 5 months.

CONCLUSIONS: Cancer survivors can enhance multiple aspects of coping with FCR through interventions such as IN FOCUS that teach mind-body resiliency techniques.

BACKGROUND: Hypertension, a major contributor to cardiovascular mortality, requires multimodal monitoring and management strategies for optimal blood pressure (BP) control. Patients are turning toward mobile health (mHealth) applications to manage hypertension which vary widely in design and regulation. This study examines the landscape of hypertension mHealth applications on Apple's App Store and Google's Play Store and qualitatively evaluates their functionality and security features from patient and clinician perspectives.

METHODS: Publicly available applications were identified using keyword "hypertension" on the Apple App Store and Google Play Store or in a recent meta-analysis that met specific review criteria. Applications with <1,000 reviews (Apple Store) or < 10,000 reviews (Google Play Store) were excluded to capture the top 5% of applications with high public use. Of > 700 applications, 43 underwent full application screening and eighteen were reviewed for general information, storage, revenue models, security, patient/clinician interfaces, and associated research. Discrepancies were resolved through consensus and available manufacturer confirmation.

RESULTS: Clinician interfaces were largely absent, with limited EMR integration and alert systems. Revenue models ranged from free to subscription-based. Security and data privacy policies varied with applications lacking clear opt-out options for data collection. Patient interfaces offered BP tracking and reminders, and accessibility features. Sentiment analysis showed an overall positive view of frequently reviewed Google Play Store applications.

CONCLUSIONS: Current mHealth applications lack several features for optimal hypertension monitoring and management. Based on the range of qualitative application features assessed, we formulate a framework for developing an ideal mHealth application for optimal hypertension management.

BACKGROUND: ED disposition decisions for older adults are complex and often uncertain, yet studies rarely capture emergency physicians' real-time perspectives.

OBJECTIVE: To assess patient outcomes based on emergency physician-perceived need for admission.

DESIGN: Single-site prospective cohort study conducted between July and November 2024.

SETTING: A Boston-area academic tertiary care ED.

PARTICIPANTS: Patients aged 65 and older dispositioned by attending physicians, excluding patients who were handed off, left without being seen, or eloped.

MEASUREMENTS: Physicians rated admission need using a 5-point Likert scale (2-4 considered marginal). Primary outcome was ED disposition stratified by rating. Secondary outcomes were hospital length-of-stay (LOS), 7-day ED return, and 30-day mortality.

RESULTS: Of the 489 patients (mean age 76.9 years [SD 7.5], 51.1% female), 55.8% were non-marginal admissions, 26.0% were non-marginal discharges, and 18.2% were marginal dispositions. Patients with marginal dispositions had longer workup times than non-marginal admissions or discharges (3.3 vs. 2.8 vs. 2.4 h, p < 0.05). Thirty-day mortality was greater for non-marginal admissions (8.8%) than non-marginal discharges (1.6%, p = 0.01), but not significantly different than marginal dispositions (3.4%). Marginal admissions had shorter median LOS (3.1 vs. 5 days, p < 0.01) and higher early discharge rates (27.8% vs. 13.2%, p = 0.01) than non-marginal admissions. Marginal discharges had fewer 7-day returns than non-marginal discharges (0% vs. 11.7%, p = 0.04). For marginal cases, physicians discussed admission benefits more than risks (70.1% vs. 43.3%, p < 0.01) for marginal cases.

LIMITATIONS: Single-site and need for admission were reported contemporaneous with disposition decision.

CONCLUSIONS: One in six older adult ED dispositions was identified as marginal. These patients are potential targets for shared decision-making and alternative care pathways.

BACKGROUND: Frailty is a proxy for biologic aging that confers risk independently of chronologic age. Most frailty indices correlate strongly with chronologic age, making independent features of biologic aging challenging to identify.

METHODS: We aimed to create a novel Age Less-Dependent Frailty (AGELESS) Score less-associated with chronologic age than the Fried frailty phenotype. Among Cardiovascular Health Study participants with available echocardiographic data, we identified demographic, clinical, serologic, and echocardiographic variables more correlated with a continuous version of the Fried frailty phenotype than age, then used LASSO regression for variable selection. In a 25% leave-out sample, we internally validated the score's association with age-adjusted all-cause and cardiovascular mortality and compared model characteristics with the Fried frailty phenotype.

RESULTS: In 4,029 individuals (mean age 72 ± 5.0 years, 59.6% female), serum cystatin C, depression, diabetes, educational attainment, forced expiratory volume in 1 s, and income were more associated with frailty than age and selected for inclusion in the AGELESS Score. Adjusted for age, individuals in the highest vs. lowest quartiles of the AGELESS Score had a higher risk of all-cause (HR: 1.44, 95% CI: 1.17-1.79, p < 0.001) and CV death (HR: 1.64, 95% CI: 1.43-1.87, p = 0.002). The AGELESS Score was less correlated with age (AGELESS r = 0.23, 95% CI: 0.16-0.30; Fried r = 0.28, 95% CI: 0.21-0.34; p-value for comparison of correlations < 0.001) and more closely associated with all-cause and CV mortality within each age quartile than the Fried frailty phenotype.

CONCLUSIONS: We derived and internally validated a novel frailty score that is less associated with chronologic age than existing indices and predicts mortality within age strata better than the existing reference standard for phenotypic frailty. This score could help identify high-risk patients with frailty across the age spectrum and may provide insights into mechanisms of biologic aging.

BACKGROUND: Limited access to primary care may disproportionately affect older adults, who often have greater chronic disease management and care coordination needs. However, little is known about the effect of having a primary care practitioner (PCP) on longevity in the aging population.

OBJECTIVE: To examine the association of having a usual source of primary care with mortality and life expectancy among US adults aged 65 and older.

DESIGN: Retrospective cohort study, using nationally representative data from the 2000 and 2005 cohorts of the National Health Interview Survey linked with National Death Index records through 2019.

PARTICIPANTS: All respondents aged 65 to 84 (n = 10,873, weighted n = 16,484,914).

INTERVENTIONS/EXPOSURES: Having a usual source of primary care.

MAIN MEASURES: Using a Cox proportional hazards model, we examined the association between exposure to primary care and 15-year mortality, adjusting for sociodemographic factors and respondent life expectancy (using a validated index). We also used this model to generate survival curves by exposure to primary care and computed median survival times for each group.

KEY RESULTS: Overall, 60.3% of respondents were female, 83.6% were non-Hispanic White, and 6.4% (n = 739, weighted n = 1,056,554) did not have a usual source of primary care. Use of primary care was associated with a lower 15-year mortality risk (aHR: 0.84, 95% CI: 0.72-0.98). Median survival time was also at least 2.1 years longer among those who used primary care (> 15 years) compared to those who did not (12.9 years).

CONCLUSIONS: We found that primary care use is associated with greater survival among older adults. As the population of adults aged 65 + is growing rapidly, investing in primary care is essential for the health of US older adults.

Conventional cuff-based blood pressure (BP) monitoring has several limitations, including patient discomfort with arm cuff inflation, inconvenience, and limited frequency of readings. Cuffless BP devices, which are increasingly available for purchase on the international market, have the potential to remove barriers to BP measurement in both research and clinical care. However, there are unanswered questions on whether, how, and in what settings these devices may be appropriate for use. Gaps include the need to understand whether the somewhat distinctive and often enormous volume of readings obtained by these devices have meaningful relationships with clinical outcomes and are appropriate for determining actionable interventions. Furthermore, international standards for determining the accuracy of some, but not yet all, of these devices only recently became available and do not provide a full assessment of the typical use of the devices. Thus, the devices on the market have not yet been adequately vetted for accuracy and efficacy. Several of these devices, however, have been cleared by the US Food and Drug Administration and are being used clinically. Moreover, many patients use cuffless devices for BP self-monitoring, often without disclosing this information to health care professionals. This scientific statement provides an overview of the existing literature on cuffless BP monitoring technologies and their potential future applications, and stresses the importance of understanding the gaps that need to be filled before these devices can be used clinically, recognizing that currently available devices may be inappropriate for clinical use.