Baroreflex sensitivity in frailty syndrome

Recent Advances and Future Directions in Syncope Management: A Comprehensive Narrative Review

Syncope is a highly prevalent clinical condition characterized by a rapid, complete, and brief loss of consciousness, followed by full recovery caused by cerebral hypoperfusion. This symptom carries significance, as its potential underlying causes may involve the heart, blood pressure, or brain, leading to a spectrum of consequences, from sudden death to compromised quality of life. Various factors contribute to syncope, and adhering to a precise diagnostic pathway can enhance diagnostic accuracy and treatment effectiveness. A standardized initial assessment, risk stratification, and appropriate test identification facilitate determining the underlying cause in the majority of cases. New technologies, including artificial intelligence and smart devices, may have the potential to reshape syncope management into a proactive, personalized, and data-centric model, ultimately enhancing patient outcomes and quality of life. This review addresses key aspects of syncope management, including pathogenesis, current diagnostic testing options, treatments, and considerations in the geriatric population.

Frail OLDER ADULTS are more likely TO have autonomic dysfunction: A systematic review and META-ANALYSIs

Autonomic dysfunction and frailty are two common and complex geriatric syndromes. Their prevalence increases with age and they have similar negative health outcomes. In PubMed and Web of Science we screened studies identifying a relationship between autonomic function (AF) and frailty in adults aged ≥65 years. Twenty-two studies of which two prospective and 20 cross-sectional were included (n=8375). We performed a meta-analysis for the articles addressing orthostatic hypotension (OH). Frailty was associated with 1.6 higher odds of suffering from consensus OH (COH) {OR=1.607 95%CI [1.15-2.24]; 7 studies; n=3488}. When measured for each type of OH the largest trend was seen between initial OH (IOH) and frailty {OR=3.08; 95%CI [1.50-6.36]; 2 studies; n=497}. Fourteen studies reported other autonomic function alterations in frail older adults with 4-22% reduction in orthostatic heart rate increase, 6% reduction in systolic blood pressure recovery, 9-75% reduction in most common used heart rate variability (HRV) parameters. Frail older adults were more likely to have impaired AF. Diagnosis of frailty should promptly lead to orthostatic testing as OH implicates specific treatment modalities, which differ from frailty management. As IOH is most strongly correlated with frailty, continuous beat to beat blood pressure measurements should be performed when present at least until cut-off values for heart rate variability testing are defined.

Association between preoperative autonomic nervous system function and post-induction hypotension in elderly patients: a protocol for a cohort study

INTRODUCTION

Post-induction hypotension (PIH), which is prevalent among elderly patients, is associated with adverse perioperative outcomes. As a critical part of blood pressure regulation, baroreflex control is believed to be closely related to intraoperative blood pressure fluctuations. Spontaneous baroreflex sensitivity and heart rate variability measurement can aid evaluation of patients' autonomic function. This study aims to determine the association between preoperative decreased baroreflex function and PIH in elderly patients.

METHODS AND ANALYSIS

This prospective cohort study will enrol patients who are 65 years old and above, scheduled for elective non-cardiac surgery under general anaesthesia, and American Society of Anesthesiologists physical status I-III (n=180). Baseline assessment will include routine preoperative evaluations as well as symptoms and anamneses associated with baroreflex failure. Preoperative autonomic function monitoring will be performed through 20 min of continuous beat-to-beat heart rate and blood pressure monitoring using LiDCO rapid (Masimo Corporation, USA). The primary outcome will be PIH. Detailed use of anaesthetic agents during induction and maintenance will be documented for adjustment in multivariable analyses.

ETHICS AND DISSEMINATION

The Research Ethics Committee of Peking Union Medical College Hospital approved the study protocol (I-22PJ008). We aim to publish and disseminate our findings in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05425147.

Blood Pressure Signal Entropy as a Novel Marker of Physical Frailty: Results from the FRAILMatics Clinical Cohort

In this study we investigated the association between information entropy in short length blood pressure signals and physical frailty status, in a group of patients aged 50+ recruited from the Falls and Syncope Unit at the Mercer's Institute for Successful Ageing in St James's Hospital, Dublin, Ireland. This work is an external clinical validation of findings previously derived in a population-based cohort from The Irish Longitudinal Study on Ageing (TILDA). The hypothesis under investigation was that dysregulation (as quantified by entropy) in continuous non-invasive blood pressure signals could provide a clinically useful marker of physical frailty status. We found that in the 100 patients investigated, higher entropy in continuously measured resting state diastolic blood pressure was associated with worse physical frailty score, as measured by the Frailty Instrument for primary care of the Survey of Health, Ageing and Retirement in Europe (SHARE-FI). Since physical frailty is defined as a pre-disability state and hence it can be difficult for clinicians to identify at an early stage, the quantification of entropy in short length cardiovascular signals could provide a clinically useful marker of the physiological dysregulations that underlie physical frailty, potentially aiding in identifying individuals at higher risk of adverse health outcomes.

Orthostatic intolerance: a frailty marker for older adults

PURPOSE

Frailty, orthostatic blood pressure changes (OBPC), and orthostatic intolerance syndrome (OIS) are common in geriatric patients. However, the results of the studies evaluating the relationship between these entities are discordant. We aimed to investigate the association between frailty and OIS with or without OBPC.

METHODS

Comprehensive geriatric assessment (CGA), frailty assessment, OBPC evaluations in the active-standing test (1st, 3rd, 5th, and 10th min), OIS investigation both in history before the test (self-reported OIS) and emerged during the active-standing test, and sarcopenia assessment via BIA and handgrip strength (HGS) were performed in 102 geriatric outpatients.

RESULTS

Patients were divided into three categories according to their frailty status (non-frail, prefrail, and frail) by Modified Fried Frailty Index (FFI) and Clinical Frailty Scale (CFS). Prevalence of self-reported OIS and OIS during the test were statistically higher in the frail group assessed by both frailty scales (P value: 0.001 for CFS, P value < 0.0001 for FFI, and P value: 0.001 for CFS, P value: 0.007 for FFI, respectively). Logistic regression analysis showed that OIS significantly increased frailty assessed both by FFI and CFS, when adjusted for age, sex, comorbidities, CGA, and sarcopenia (For FFI, OR: 19.37; 95% CI: 2.38-157.14; P value: 0.006 and for CFS OR: 4.32; 95% CI: 1.184-11.47; P value: 0.003, respectively).

CONCLUSION

To the best of our knowledge, this is the first study defining OIS as symptoms both self-reported and provoked during the test, and showed a strong correlation between OIS and frailty. OIS may be defined as a multifactorial and independent marker for frailty, regardless of OBPC. Further prospective investigations are warranted to support the relationships between OIS and frailty.

Multicomponent exercise training in cardiovascular complexity in prefrail older adults: a randomized blinded clinical pilot study

The aim of this study was to investigate the effects of multicomponent training on baroreflex sensitivity (BRS) and heart rate (HR) complexity of prefrail older adults. Twenty-one prefrail community-dwelling older adults were randomized and divided into multicomponent training intervention group (MulTI) and control group (CG). MulTI performed multicomponent exercise training over 16 weeks and CG was oriented to follow their own daily activities. The RR interval (RRi) and blood pressure (BP) series were recorded for 15 min in supine and 15 min in orthostatic positions, and calculation of BRS (phase, coherence, and gain) and HR complexity (sample entropy) were performed. A linear mixed model was applied for group, assessments, and their interaction effects in supine position. The same test was used to assess the active postural maneuver and it was applied separately to each group considering assessments (baseline and post-intervention) and positions (supine and orthostatic). The significance level established was 5%. Cardiovascular control was impaired in prefrail older adults in supine position. Significant interactions were not observed between groups or assessments in terms of cardiovascular parameters. A 16-week multicomponent exercise training did not improve HR complexity or BRS in supine rest or in active postural maneuver in prefrail older adults.

Associations between Neurocardiovascular Signal Entropy and Physical Frailty

In this cross-sectional study, the relationship between noninvasively measured neurocardiovascular signal entropy and physical frailty was explored in a sample of community-dwelling older adults from The Irish Longitudinal Study on Ageing (TILDA). The hypothesis under investigation was that dysfunction in the neurovascular and cardiovascular systems, as quantified by short-length signal complexity during a lying-to-stand test (active stand), could provide a marker for frailty. Frailty status (i.e., "non-frail", "pre-frail", and "frail") was based on Fried's criteria (i.e., exhaustion, unexplained weight loss, weakness, slowness, and low physical activity). Approximate entropy (ApEn) and sample entropy (SampEn) were calculated during resting (lying down), active standing, and recovery phases. There was continuously measured blood pressure/heart rate data from 2645 individuals (53.0% female) and frontal lobe tissue oxygenation data from 2225 participants (52.3% female); both samples had a mean (SD) age of 64.3 (7.7) years. Results revealed statistically significant associations between neurocardiovascular signal entropy and frailty status. Entropy differences between non-frail and pre-frail/frail were greater during resting state compared with standing and recovery phases. Compared with ApEn, SampEn seemed to have better discriminating power between non-frail and pre-frail/frail individuals. The quantification of entropy in short length neurocardiovascular signals could provide a clinically useful marker of the multiple physiological dysregulations that underlie physical frailty.