Short-term Blood Pressure Variability Research Articles

Effects of continuous positive airway pressure on very short-term blood pressure variability associated with sleep-disordered breathing by pulse transit time-based blood pressure measurements.

Blood pressure (BP) variability (BPV) is a predictor of cardiovascular outcomes independently of BP absolute values. We previously reported that pulse transit time (PTT) enables monitoring beat-to-beat BP, identifying a strong relationship between the extent of very short-term BPV and the severity of sleep-disordered breathing (SDB). Here, we investigated the effects of continuous positive airway pressure (CPAP) on very short-term BPV. We studied 66 patients (mean age 62 years old, 73% male) with newly diagnosed SDB who underwent full polysomnography on two consecutive days for diagnosis (baseline) and CPAP, together with PTT-driven BP continuous recording. PTT index was defined as the average number of acute transient rises in BP (≥12 mmHg) within 30 s/h. CPAP treatment effectively improved SDB parameters, and attenuated PTT-based BP absolute values during the night-time. Very short-term BPV that includes PTT index and standard deviation (SD) of systolic PTT-BP was significantly reduced by CPAP therapy. The changes in PTT index from baseline to CPAP were positively correlated with the changes in apnea-hypopnea index, obstructive apnea index (OAI), oxygen desaturation index, minimal SpO 2 , and mean SpO 2 . Multivariate regression analysis revealed that changes in OAI and minimal SpO 2 , as well as heart failure, were the independent factors in determining the reduction of PTT index following CPAP. PTT-driven BP monitoring discovered the favorable effects of CPAP on very short-term BPV associated with SDB events. Targeting very short-term BPV may be a novel approach to identifying individuals who experience greater benefits from CPAP.

Kidney transplantation and kidney donation do not affect short-term blood pressure variability

Purpose Blood pressure variability (BPV) is an independent cardiovascular risk factor in CKD. Kidney transplantation (KTx) is associated with improved BP levels for kidney transplant recipient (KTRs), without evoking significant changes in donors. The aim of this study was to assess the short- and mid-time effects of KTx and donation on short-term BPV in KTRs and their respective living kidney donors. Materials and Methods Forty KTRs and their respective donors were evaluated with 24-h ABPM (Mobil-O-Graph-NG) at baseline (1 month before), 3-months and 12-months after KTx. Standard-deviation (SD), weighted-SD (wSD), coefficient-of-variation (CV), average-real-variability (ARV) and variability independent of mean (VIM) for SBP/DBP were calculated with validated formulas Results All 24-h systolic and diastolic BPV indexes studied did not change significantly from baseline to 3-month (SBP-wSD: 12.8 ± 3.0 vs 13.2 ± 3.4 mmHg, p = 0.608; SBP-ARV: 10.3 ± 2.4 vs 10.8 ± 2.6 mmHg, p = 0.463) and 12-month evaluation (SBP-wSD 12.8 ± 3.0 vs 12.1 ± 2.8; p = 0.424 and SBP-ARV: 10.3 ± 2.4 vs 10.2 ± 2.5; p = 0.615) after kidney transplantation in the KTRs.In kidney donors, all 24-h systolic BPV indices displayed a trend towards higher values at 3 months compared to baseline, but without reaching statistical significance (SBP-wSD: 12.2 ± 2.8 vs 13.6 ± 4.2 mmHg, p = 0.107 and SBP-ARV: 10.1 ± 2.1 vs 11.2 ± 3.1 mmHg, p = 0.099), the levels of 24-h systolic SBP indices at 12-months were almost identical to baseline values. 24-h diastolic BPV indices at 3-month and 12-month evaluation were similar to baseline. Conclusion Short-term BPV did not change significantly 3 and 12 months after kidney transplantation/donation neither in KTRs nor in living kidney donors. Longitudinal studies examining associations of BPV with adverse outcomes in these individuals are needed.

PS-BPC04-2: ASSOCIATION OF SHORT-TERM BLOOD PRESSURE VARIABILITY AND MICROALBUMINURIA IN ESSENTIAL HYPERTENSION: DIFFERENCES ACCORDING TO CLASSIFICATIONS OF BLOOD PRESSURE ABSOLUTE VALUE

Objective: Increased short-term blood pressure (BP) variability has been highlighted as a novel risk for cardiovascular diseases. The influence of short-term BP variability on cardiovascular mortality is also accelerated together with increase in BP. In essential hypertension, short-term BP variability is independently associated with early renal abnormalities. In this study, the associations of short-term BP variability with microalbuminuria were analyzed according to classifications of BP absolute value in essential hypertensive patients. Design and method: In 222 untreated essential hypertensive patients (127 males, average age 55 ± 11 years) without chronic kidney disease (urinary albumin excretion less than 300 mg/g of creatinine and estimated glomerular filtration rate 60 mL/min/1.73m2 or more), ambulatory BP monitoring was performed to estimate BP and the standard deviation of systolic BP (SBP-SD) during 24 hours. The 24-hour urine collection was also done to evaluate urinary albumin excretion. According to 24-hour BP level, patients were divided into 4 groups: 33 patients with BP < 130/80 mmHg (N), 71 patients with BP of 130–149/80–89 mmHg (G1), 84 patients with BP of 150–169/90–99 mmHg (G2) and 34 patients with BP 170/100 mmHg (G3). Results: 24-hour systolic BP correlated positively with urinary albumin excretion in G1, G2 and G3 groups (r = 0.25 in G1 group; r = 0.22 in G2 group; r = 0.30 in G3 group, p < 0.05, respectively), whereas there was no relation between them in N group. SBP-SD correlated positively with UAE in both G2 and G3 group (r = 0.20 in G2 group; r = 0.30 in G3 group, p < 0.05, respectively), but did not so in either N or G1 group. Thus, the correlation between SBP-SD and urinary albumin excretion was confined to patients with 24-hour BP ≧ 150/90 mmHg. Furthermore, in patients with 24-hour BP ≧ 150/90 mmHg, multiple regression analysis revealed that SBP-SD was an independent determinant for urinary albumin excretion together with 24-hour systolic BP. Conclusions: These data indicate in essential hypertensive patients, that the risk of increased short-term BP variability for microalbuminuria could be potentiated along with the elevation in BP absolute value.

Correlation Between Short-Term Blood Pressure Variability After Primary Percutaneous Coronary Intervention and Adverse Cardiovascular Events in Patients With ST Segment Elevation Myocardial Infarction

Abstract Background To investigate the relationship between short-term blood pressure variability (BPV) after primary percutaneous coronary intervention (PPCI) and adverse cardiovascular outcomes 1 year after operation in patients with acute ST segment elevation myocardial infarction (STEMI). Methods The clinical and prognostic data of 331 patients with STEMI who underwent PPCI and drug-eluting stent implantation were collected retrospectively from 2016 to 2019. The correlation between BPV within 4 days and adverse cardiovascular outcome 1 year after operation was analyzed. Blood pressure SD was used to evaluate individual systolic blood pressure variability (SBPV) and diastolic blood pressure variability (DBPV). The high SBPV and DBPV groups were defined as SD ≥11.42 and ≥8.49 mm Hg, respectively. Multivariate bivariate logistic regression model was used to explore the correlation between SBPV, DBPV, and major adverse cardiovascular events (MACE) 1 year after operation. Results The incidence of heart failure in the high SBPV group (21.1% vs. 10.3%) was significantly higher than the low SBPV group. Also, the incidence of heart failure (23.5% vs. 7.9%) and the cumulative incidence of MACE (29.5% vs. 13.9%) in the high DBPV group were higher than those in the low DBPV group (all P < 0.05). After adjusting for age, sex, body mass index, antihypertensive drugs, left ventricular ejection fraction, Gensini score, and other influencing factors, multivariate binary logistic regression analysis showed that high SBPV was a risk factor for heart failure (odds ratio [OR] = 3.462, 95% confidence interval [CI] 1.476–8.117, P = 0.004), and high DBPV was a risk factor for heart failure and cumulative MACE (OR = 4.535, 95% CI 1.725–11.926, P = 0.002; OR = 3.412, 95% CI 1.627–7.152, P = 0.001, respectively) and in the subgroup hypertensives using oral antihypertensive drugs (OR = 4.328, 95% CI 1.619–11.572, P = 0.004), as well as high DBPV for heart failure and cumulative MACE (OR = 4.600, 95% CI 1.518–13.934, P = 0.007; OR = 4.942, 95% CI 1.851–13.198, P = 0.001, respectively). Conclusions High BPV within 4 days after PPCI and drug-eluting stent implantation in STEMI patients is a cardiovascular risk factor within 1 year after operation.

PS-C08-12: SHORT-TERM BLOOD PRESSURE VARIABILITY AND TARGET-ORGAN EFFECTS IN YOUTH: THE SHIP-AHOY STUDY

Background: Increased blood pressure variability (BPV) has been associated with development of hypertensive target organ damage in adults, including left ventricular (LV) hypertrophy and increased vascular stiffness. Whether similar relationships can be seen in youth is unknown. Methods: We assessed short-term BPV and its relation to LV mass and carotid-femoral pulse wave velocity (cfPWV) in 374 participants (mean age 15.5 years, 60% male) in the SHIP-AHOY cohort. Short-term BPV was assessed by examining the differences in systolic and diastolic blood pressure (S/DBP) between 2 SHIP-AHOY study visits. Average time between visits was 25 days. BP was measured by auscultation; 4 BP measurements were conducted at each visit and averaged. BPV was calculated as the difference between the mean BP measurements at the 2 visits. LV mass was measured by m-mode echocardiography and cfPWV was assessed using plethysmography. Results: Mean SBP was 123.1 ± 13.0 mmHg on day 1, and 122.3 ± 12.8 mmHg on day 2, with a mean difference of 0.9 ± 7.5 mmHg between the visits. Mean DBP was 71.6 ± 11.6 mmHg on day 1, and 72.0 ± 11.7 mmHg on day 2, with a mean difference of 0.5 ± 10.4 mmHg between the visits. Participants were then divided into 2 groups according to whether their BPV was above (n = 198) or below (n = 176) the median BPV of the entire cohort. LV mass was similar between the groups: 32.7 ± 7.3 gram/ht^2.7 for those above the median vs. 32.8 ± 6.7 for those below the median (P = NS), but cfPWF was significantly higher in those with BPV above the median: 5.2 ± 0.9 meters/second vs. 5.0 ± 0.8 m/s for those below the median, P = 0.03. Conclusions: These data suggest that increased short-term BPV may be associated with the development of increased vascular stiffness in youth.

Cross-sectional associations between short and mid-term blood pressure variability, cognition, and vascular stiffness in older adults

High blood pressure variability (BPV), particularly in older age, appears to be an independent risk factor for incident dementia. The current study aimed to investigate the association between different BPV measures (short- and mid-term BPV including circadian patterns) and cognitive functioning as well as vascular stiffness measures to better understand the role that BPV plays in cognitive impairment. 70 older adults (60-80-year-olds) without dementia completed a cognitive test battery and had their blood pressure (BP) assessed via a 24-hour ambulatory BP monitor (divided into sleep and wake for short-term BPV) and 4-day morning and evening home-based BP monitor (for day-to-day BPV). Arterial stiffness was evaluated via pulse wave analysis and pulse wave velocity (PWV) and cerebrovascular pulsatility was assessed via transcranial doppler sonography of the middle cerebral arteries. High systolic as well as diastolic short- and mid-term BPV were associated with poorer cognitive functioning, independent of the mean BP. Higher short-term BPV was associated with poorer attention and psychomotor speed, whilst day-to-day BPV was negatively linked with executive functioning. Circadian BP patterns (dipping and morning BP surge) showed no significant relationships with cognition after adjusting for covariates. Higher systolic short-term BPV was associated with higher arterial stiffness (PWV) and higher diastolic day-to-day BPV was linked with lower arterial stiffness. No significant associations between BPV measures and cerebrovascular pulsatility were present. High BPV, independently of the mean BP, is associated with lower cognitive performance and increased arterial stiffness in older adults without clinically-relevant cognitive impairment. This highlights the role of systolic and diastolic BPV as a potential early clinical marker for cognitive impairment.

Short-term blood pressure variability is inversely related to regional amplitude of low frequency fluctuations in older and younger adults

Blood pressure variability (BPV), independent of mean blood pressure levels, is associated with cerebrovascular disease burden on MRI and postmortem evaluation. However, less is known about relationships with markers of cerebrovascular dysfunction, such as diminished spontaneous brain activity as measured by the amplitude of low frequency fluctuations (ALFF), especially in brain regions with vascular and neuronal vulnerability in aging. We investigated the relationship between short-term BPV and concurrent regional ALFF from resting state fMRI in a sample of community-dwelling older adults (n = 44) and healthy younger adults (n = 49). In older adults, elevated systolic BPV was associated with lower ALFF in widespread medial temporal regions and the anterior cingulate cortex. Higher systolic BPV in younger adults was also related to lower ALFF in the medial temporal lobe, albeit in fewer subregions, and the amygdala. There were no significant associations between systolic BPV and ALFF across the right/left whole brain or in the insular cortex in either group. Findings suggest a possible regional vulnerability to cerebrovascular dysfunction and short-term fluctuations in blood pressure. BPV may be an understudied risk factor for cerebrovascular changes in aging.

S-58-3: HOW COULD CONTINUOUS CUFFLESS AUTOMATED BLOOD PRESSURE MEASUREMENT DEVICES CONTRIBUTE TO HYPERTENSION MANAGEMENT?

Evidence that hypertension is the most importat global risk factor for cardiovascular morbidity and mortality, and demonstration of the cardiovascular protection offered by antihypertensive treatment, have been based on upper-arm cuff blood pressure (BP) measurements. This approach is recommended by current hypertension guidelines for BP measurement in clinical practice, as well as for validation of novel BP measuring devices. However, the spot or intermittent BP measurements in static conditions allowed by arm-cuff devices are unable to identify and track the continuous and rapid BP changes characterizing daily life. Moreover, cuff-based BP measurements are exposed to errors related to cuff size, shape and positioning, and cuff inflation may itself induce an alerting response and produce discomfort in the users during daily activities and in particular during sleep, which may modify the measured BP levels. To face these issues, use of continuous recordings techniques, not based on arm-cuff inflation, would be required. This is possible through intra-arterial recordings, which however are not feasible in daily practice because of their invasiveness. An alternative solution is represented by photoplethysmographic volume-clamp method for finger BP monitoring which, however, is difficult to implement in clinical practice because of its cost and complexity. Technological progress is now offering an increasingly large and heterogeneous series of cuffless BP monitors, which estimate BP based on sensors, signal processing and algorithms embedded in wearable devices, smartphones or pocket devices. These cuffless devices might allow for comfortable and continuous BP recordings, detecting rapid BP changes during day and night sleep, thus offering information on both short, mid and long term BP variability. Cuffless devices might also be useful for continuous non invasive BP monitoring in different clinical settings, including ICUs, during anaesthesia, in patients with arrhythmias, hypotension/syncope, and other transient conditions affecting BP levels and variability. Moreover, cuffless BP measurement devices connected to telemonitoring facilities or smartphones apps may improve patients empowerment, adherence to treatment and long-term BP control. In spite of all these potential advantages, however, cuffless BP devices have to face specific accuracy issues, which would need refinement of specific validation protocols aimed at testing the need of individual calibration, the stability of measurements after calibration and the device actual ability to track BP changes before they might be recommended for clinical use.

JS-HR-7: BLOOD PRESSURE VARIABILITY; THERAPEUTIC TARGET FOR THE PREVENTION OF CARDIOVASCULAR DISEASE

In the past three decades, there have been many reports on the associations of various parameters of blood pressure (BP) variability with increased risk of cardiovascular disease (CVD) events; these parameters include short term BP variability (BPV), i.e., beat-by-beat BPV and ambulatory BPV, abnormality of nocturnal BP dipping pattern, and mid- to long-term BPV, i.e., day-by-day BPV, visit-to-visit BPV, and seasonal variations in BP. Several factors that are associated with abnormal BPV, as well as environmental factors such as cold or warm temperatures and seasonal changes in climate, increase fluctuations in BP. Individual intrinsic factors such as sympathetic nervous tone, arterial stiffness, physical activity, and mental stress also contribute to elevated BPV. According to evaluations of BPV abnormalities, out-of-office BP measurements such as ambulatory and home BP monitoring are needed. Although there are issues regarding measurement accuracy, cuffless BP monitoring devices, for example, those using pulse transit time, may be used to estimate nighttime BP levels. Such cuffless BP devices can also evaluate beat-by-beat BPV. Moreover, by using the multisensor-equipped ambulatory BP monitoring device developed by our research group, it is possible to evaluate BPV associated with changes in temperature, physical activity, and/or atmospheric pressure. Based on the mechanism(s) behind a given patients BPV abnormality, several methods may be considered for the management of that abnormality (Figure). For example, improving excessive sympathetic nervous system activation may be useful in the management of BPV abnormality, and renal denervation has been reported to decrease ambulatory BPV. Abnormal nocturnal BP dipping may be treated by decreasing nighttime BP. Moreover, early adjustment of antihypertensive drugs has been reported to be useful in suppressing seasonal variations in BP, leading to a decreased risk of CVD events. Furthermore, housing conditions and room temperature are closely related to BP levels, and adaptive control of room temperature would be useful to suppress winter increases in BP. In clinical practice, we must not forget that BPV parameters are interrelated. For instance, frequent evaluation of BP levels and adjustment of antihypertensive drugs can suppress visit-to-visit BPV, which in turn leads to the suppression of seasonal variations in BP. Over the next decade, greater data on how to manage and control BPV need to be accumulated. Additionally, future studies should be conducted to verify whether the different types of BVP management are useful in preventing CVD events.

PS-BPC03-1: DEVELOPMENT OF CUFFLESS AND CALIBRATION-LESS BLOOD PRESSURE MEASUREMENTS

Objective: The characteristics of dynamic short-term blood pressure variability caused by numerous triggers vary greatly among individuals. Wearable devices that continuously and noninvasively capture beat-by-beat blood pressure values are a necessity to further study blood pressure. The development of cuffless blood pressure measurements, which, unlike sphygmomanometers, do not require pressurization and depressurization time, has attracted much attention in recent years for its potential to capture beat-by-beat blood pressure values. However, cuffless blood pressure measurements approved in Europe and the United States require calibration before use. This indicates that the function is limited to estimation of blood pressure variation from the time of calibration. In this study, we conducted a measurement test aiming at the practical application of the cuffless and calibration-less blood pressure measurements. Design and Method: In this study, we recruited adults aged 20 years and older to evaluate whether a wearable device without pre-calibration could meet the standards of BHS, ESH, ISO81060–2:2018 and IEEE1708a-2019 and ensure the same accuracy as existing sphygmomanometers. For each measurement test, the cuff was wrapped around the subject's upper left arm and a wearable device was attached to the ipsilateral wrist, and the subject was asked to maintain a sitting posture. Measurements were taken with the reference sphygmomanometer every 3 minutes for 7 times. To minimize the effect of the venous congestion on the measurements, the measurement period with the wearable device was from 30 seconds after the completion of the cuff depressurization until the start of the next pressurization. The blood pressure value measured by the wearable device was evaluated against the average of the values measured by the reference sphygmomanometer before and after. Results: 219 participants were included in the analysis. Participants with systolic blood pressure values ranging from 80 to 204 and diastolic blood pressure values ranging from 46 to 140 were included. The mean and SD of the differences between the estimates and the reference were -1.27 ± 4.97 mmHg for SBP and 0.74 ± 2.55 mmHg for DBP. Conclusion: The overall accuracy of the cuffless and calibration-less blood pressure measurements device satisfied the criteria shown in ISO81060–2 against various adults in the sitting posture. This study showed the strong potential of the cuffless and calibration-less blood pressure measurements.

Modern aspects of short-term blood presssure variability in arterial hypertension

Abstract. Arterial hypertension is an important public health problem worldwide due to its high incidence and associated risks of cardiovascular and renal diseases such as coronary heart disease, cerebrovascular disease, chronic kidney disease. The level of blood pressure is the main indicator of hypertension treatment effectiveness and leading cardiovascular risk factor. Blood pressure is one of the most dynamic physiological parameters, which is characterized by continuous and significant changes beat-to-beat, over 24 h, day-to-day, and visit-to-visit. Under physiological conditions, these blood pressure variations are mostly represent a response to environmental stimulation aimed at maintaining cardiovascular homeostasis. However, a persistent increase in the blood pressure variability may be the result of pathological changes in the mechanisms of cardiovascular regulation, which leads to alterations in cardiovascular system functioning with the subsequent development of cardiovascular diseases and complications. The phenomenon of blood pressure variability has been known for a long time. It was first described by the English physiologist Stephen Gales in 1733, and its assessment in clinical conditions became possible at the end of the 19th – beginning of the 20th century, after the invention of the sphygmomanometer and the introduction of non-invasive blood pressure measurement using the Riva-Rocci and Korotkov methods. Historically, blood pressure variability has been viewed as a random factor caused by measurement error, which prevents accurate blood pressure measurement. Вlood pressure variability was considered the so-called «background noise», which was not given any importance and tried to overcome with the help of improving monitoring. However, already at the end of the last century, the discussion of the clinical significance of this indicator in patients with hypertension began. The clinical significance and prognostic implications of blood pressure variability have been demonstrated by a series of clinical and population-based studies conducted in recent years, in which elevated blood pressure variability was associated with a higher risk of target organ damage, cardiovascular events, cardiovascular and total mortality independently of blood pressure level. The review presents modern concepts of blood pressure variability, its classification, and assessment methods. The pathogenetic significance of short-term BP variability in patients with arterial hypertension is reviewed, with a discussion of the available evidence regarding the significance of short-term blood pressure variability in cardiovascular risk stratification.

Blood pressure regulation change with ageing: in-depth analysis of 1439 subjects with arterial hypertension and autonomic neuropathy.

Introduction: Blood pressure (BP) regulation is affected by ageing through different mechanisms, including alteration of neural control. Blood pressure variability (BPV) and heart rate variability (HRV) reflect the interaction of BP control mechanisms, and both increased BPV and reduced HRV have been associated to increased cardiovascular morbidity and mortality. The objective of this study was to assess BPV and HRV in hypertensive subjects in different age ranges and to compare them with subjects with established primary cardiovascular dysautonomia, i.e., Parkinson and related diseases. Methods: The study will include 1,439 subjects, divided in three groups: 777 hypertensive subjects aged 40-55 years, 601 hypertensive subjects aged 75-95 years, and 61 patients with primary cardiovascular autonomic neuropathy. Short-term BPV will be assessed through standard deviation (SD), weighted standard deviation (wSD), average real variability (ARV), coefficient of variation (CV), and variability independent of mean (VIM) of 24h ambulatory BP monitoring (ABPM). HRV will be evaluated by SD and CV of heart rate measured during ABPM. Expected outcomes: The expected outcomes of this study include the comparison of overall BPV and mid-term HRV among the three study subgroups, in order to identify similarities and differences in these indexes and to highlight possible common pathophysiological pathways. Furthermore, the characteristics associated with higher BPV and HRV will be analyzed in the three subgroups and compared among them. Similarly, differences in dipping and orthostatic hypotension prevalence will be assessed and characteristics associated with non-dipping status and presence of orthostatic hypotension will be reported. Finally, the association of increased BPV and reduced HRV with organ damage and cardiovascular morbidity will be evaluated.

Concurrent Aerobic Plus Resistance Training Elicits Different Effects on Short-Term Blood Pressure Variability of Hypertensive Patients in Relation to Their Nocturnal Blood Pressure Pattern.

Background and Objectives: The purpose of this study was to investigate the effects of a 12-week concurrent training (CT) (i.e., aerobic plus resistance exercise) on short-term blood pressure variability (BPV) and BP values in hypertensive patients with non-dippper BP nocturnal pattern and underlying coronary artery disease. Material and Methods: The study included 72 consecutive patients who were divided into two groups according to the nocturnal BP pattern: dipping pattern (33 pts) and non-dipping (39 pts). Before starting CT and at 12 weeks, patients underwent the six minute walk test, ergometric test, assessment of 1-repetiton maximum (1 RM), and 24/h BP monitoring (24-h ABPM). Results: After CT, exercise capacity increased in both groups in a similar fashion. Twenty-four/h systolic BPV and daytime systolic BPV decreased significantly in the dipping group while they were unchanged in the non-dipping group (between groups changes: -1.0 ± 0.4 mmHg and -1.3 ± 0.9 mmHg; p = 0.02 and p = 0.006, respectively). Twenty-four/h systolic BP and daytime systolic BP decreased significantly in the dipping group while they were unchanged in the non-dipping group (between groups changes: -7.1 ± 2.6 mmHg and -7.8 ± 2.4 mmHg; p = 0.004 and p = 0.002, respectively). Nighttime systolic BP and BPV was unchanged in both groups. Twenty-four/h diastolic BP presented small but not significant changes in both groups. Conclusions: The effects of CT on BPV and BP were blunted in hypertensive subjects with a non-dipping BP pattern.

Abstract 9881: Effects of CPAP on Very Short-Term Blood Pressure Variability Associated With Sleep-Disordered Breathing Determined by Pulse-Transit-Time-Based Blood Pressure Measurements

Background: Sleep-disordered breathing (SDB) and blood pressure (BP) variability are closely associated with cardiovascular diseases. We have recently reported that pulse-transit-time (PTT) has enabled to monitor the beat-to-beat BP, identifying a strong relationship between the severity of SDB and the extent to very short-term BP variability. Here, we investigated the effects of continuous positive airway pressure (CPAP) on very short-term BP variability. Methods: We studied 57 patients (mean age 61 years old, male 42) with SDB who underwent the full polysomnography on two consecutive days for diagnosis (baseline) and CPAP. PTT was continuously monitored together, and PTT-based BP values were measured on a beat-to-beat basis. PTT index was defined as the average number of acute transient rises in BP (≥12 mmHg) within 30 seconds per hour. Results: Apnea-hypopnea index (AHI) was decreased from 46.5±22.4 to 13.7±15.0 (P<0.01) by CPAP. CPAP significantly lowered the average value of systolic PTT-based BP from 121±21 to 118±20 mmHg (P=0.04). Importantly, CPAP significantly reduced the PTT index from 31.4±20.1 to 20.8±15.6 (P<0.01) as well as the standard deviation (SD) of systolic PTT-BP from 5.3±1.9 to 4.9±1.4 mmHg (P=0.01), suggesting that very short-term BP variability was improved by CPAP ( Figure ). The changes in PTT index after CPAP were significantly correlated with the improvement in AHI (R=0.55), oxygen desaturation index (R=0.36), minimal SpO 2 (R=0.48), mean SpO 2 (R=0.46), and arousal index (R=0.58). In multivariate linear regression analysis, the change in AHI was the independent factor to determine the reduction of the PTT index after CPAP. Conclusion: PTT-based BP discovered the improvement in very short-term BP variability associated with SDB events by CPAP therapy.

Abstract 14300: Arterial Stiffness is Associated With Intermediate-Term Home Blood Pressure Variability: The Electronic Framingham Heart Study

Introduction: Short-term blood pressure variability (BPV) is associated with arterial stiffness in patients with hypertension. Few studies examined associations between arterial stiffness and digital home BPV over an intermediate time span. Objective: We investigated if antecedent arterial stiffness was associated with home BPV among participants in the electronic Framingham Heart Study (eFHS). We hypothesize that higher arterial stiffness predicts higher intermediate-term home BPV over one-year follow-up. Methods: At an FHS research exam (2016-2019), participants underwent arterial tonometry to acquire mean arterial pressure (MAP) and measures of arterial stiffness (carotid femoral pulse wave velocity, CFPWV; forward pressure wave amplitude, FWA) and wave reflection (reflection coefficient, RC). Participants who agreed to enroll in eFHS were provided with a digital blood pressure (BP) cuff to measure home BP weekly. Participants with < 3 weeks of BP readings were excluded. Linear regression models were used to examine associations of arterial measures with home average real variability (ARV) of systolic (SBP) and diastolic (DBP) BP adjusting for covariates. We obtained ARV as an average of the absolute differences of consecutive BP measurements. ARV considers not only the dispersion of the BP readings around the mean, but also the order of BP readings. We used p<0.05 for significance. Results: Among 857 eFHS participants (mean age 54 years, 59% women, mean BP 119/76, 47% hypertension, mean ARV of DBP 5.50, mean ARV of SBP 8.61), higher FWA and RC were associated with higher ARV of SBP ( Table ). Higher CFPWV was associated with lower ARV of DBP ( Table ). Conclusion: In eFHS, higher FWA and RC were associated with higher intermediate-term home BPV of SBP while higher CFPWV was associated with blunted BPV of DBP. Our findings suggest that higher aortic stiffness and wave reflection may affect day-to-day modulation of blood pressure in a home-based setting.

Abstract 12632: Relationships Between Circadian Ambulatory Systolic Blood Pressure Variability With Subclinical Atherosclerosis in Healthy Middle-Aged Individuals

Background: Short-term fluctuations in blood pressure (BP) as measured by 24-hr ambulatory BP monitoring (ABPM) is associated with subclinical atherosclerosis in the general population. However, whether short-term blood pressure variability (BPV) in the day versus night-time has differential effects on the development of subclinical atherosclerosis is uncertain. Methods and Results: We investigated the relationship between mean 24-hr BP and BPV parameters with common carotid artery intima-media thickness (CIMT) in 305 middle-aged Chinese (mean age 54±7years, 45% male) free from hypertension, hyperlipidaemia, diabetes or cardiovascular diseases. Subclinical atherosclerosis with elevated CIMT was defined as >75th percentile of CIMT of the overall study cohort. Linear regression models adjusted for age, sex, body mass index and smoking status revealed significant associations between office, day- and night-time mean SBP, day-time SBP standard deviation (SD) and coefficient of variation (CV) with elevated CIMT (all p<0.05). As shown in the Table , logistic regression analysis demonstrated that only ABPM day-time mean SBP (odds ratio [OR]:2.54, 95% confidence interval [95%CI]:1.29-5.00), night-time mean SBP (OR:3.23, 95%CI:1.67-6.22), night-time mean DBP (OR:2.27, 95%CI:1.16-4.42), day-time SBP CV (OR:0.47, 95%CI:0.26-0.86) and night-time SBP SD (OR1.94, 1.05-3.58) predicted the occurrence of subclinical atherosclerosis (all p<0.05). Conclusions: In healthy middle-age individuals without known hypertension, mean day and night-time SBP as measured using ABPM provided the strongest positive predictive value for elevated CIMT. Interestingly, increase day-time SBP CV versus night-time SBP SD have opposite effects on CIMT, suggesting circadian changes in SBP might have distinct contributions to the development of subclinical atherosclerosis.

Sex-related short-term blood pressure variability differences in kidney transplant recipients.

Kidney transplant recipients (KTRs) display higher cardiovascular morbidity and mortality than the general population. Increased short-term blood pressure variability (BPV) is associated with a higher risk of adverse cardiovascular outcomes in chronic kidney disease (CKD). The aim of this study is to investigate sex differences in short-term BPV in KTRs. In total, 136 male and 69 female KTRs with valid 24 h ambulatory blood pressure monitoring were included in this analysis. Systolic and diastolic BPV indices [SD, weighted SD (wSD), coefficient of variation (CV), average real variability (ARV) and variability independent of the mean (VIM)] were calculated with validated formulas for the 24 h, daytime and nighttime periods. Age, time from transplantation surgery and history of major comorbidities did not differ between men and women. During the 24-h period, systolic BPV indices did not differ between men and women (SBP-ARV: 9.4 ± 2.2 vs. 9.9 ± 2.5; P = 0.212). During the daytime period, SBP-CV and SBP-VIM were significantly higher in females compared with male participants (SBP-CV: 9.9 ± 2.4 vs. 11 ± 3.1%; P = 0.022 and SBP-VIM: 12.6 ± 3.0 vs 14.2 ± 3.9; P = 0.008); daytime SBP-SD and SBP-ARV, and all studied indexes during nighttime did not differ between groups. No significant between-group differences in 24 h and daytime diastolic BPV indices were detected. Nighttime DBP-CV was marginally higher in men (12.0 ± 3.6 vs. 11.4 ± 4.0; P = 0.053); the rest nighttime diastolic BPV indices measured were also nonsignificantly higher in men. In conclusion, 24-h systolic and diastolic BPV parameters did not differ between male and female KTRs, but short-term BPV over the respective day- and nighttime periods showed different trends in men and women. Further studies are needed to examine possible differences in long-term BPV in KTRs.

Short-term Blood Pressure Variability and Incident CKD in Patients With Hypertension: Findings From the Cardiovascular and Metabolic Disease Etiology Research Center–High Risk (CMERC-HI) Study

The association between short-term blood pressure variability (BPV) and kidney outcomes is poorly understood. This study evaluated the association between short-term BPV and kidney disease outcomes in people with hypertension. Prospective observational cohort study. 1,173 hypertensive participants in the Cardiovascular and Metabolic Disease Etiology Research Center-High Risk (2013-2018) Study with estimated glomerular filtration rate (eGFR)≥60mL/min/1.73m2. Short-term BPV assessed by average real variability (ARV). Composite kidney disease outcome (30% decline in eGFR from baseline, new occurrence of eGFR<60mL/min/1.73m2, or onset of UACR >300mg/g). Multivariable Cox regression analyses to evaluate the association between systolic and diastolic BP ARV (SBP-ARV and DBP-ARV) and outcomes. During a median follow-up of 5.4 [4.1-6.5] years, 271 events of the composite kidney disease outcome occurred (46.5 per 1,000 person-years). Multivariable Cox analysis revealed that the highest SBP-ARV and DBP-ARV tertiles were associated with a higher risk of the composite kidney disease outcome than the lowest tertiles, independent of the 24-hour SBP or DBP levels (HR, 1.64 [95% CI, 1.16-2.33], and 1.60 [95% CI, 1.15-2.24] for SBP-ARV and DBP-ARV, respectively). These associations were consistent when SBP-ARV and DBP-ARV were treated as continuous variables (HR per 1.0-unit greater SBP-ARV, 1.03 [95% CI, 1.01-1.06]; HR per 1.0-unit greater DBP-ARV, 1.04 [95% CI, 1.01-1.08]). These associations were consistent, irrespective of subgroups (age, sex, 24-hour SBP or DBP, and moderate albuminuria). However, other measures of short-term BPV including SD, coefficient of variation, and dipping patterns were not associated with the composite kidney disease outcome. Observational study design, the use of single measurement of 24-hour BP, lack of information on changes in antihypertensive medication during the follow-up. Short-term BPV is associated with the development of a composite kidney disease outcome in hypertensive patients.

Short-term blood pressure variability and outcomes in non-dialysis chronic kidney disease.

BackgroundBlood pressure variability (BPV) is associated with cardiovascular and all-cause mortality, and has been demonstrated in dialysis patients, but has been poorly studied and remains controversial in non-dialysis chronic kidney disease (CKD) patients. We investigated the effect of short-term BPV on prognosis in this population.MethodsA total of 245 stage 1–4 CKD patients with 24-h ambulatory blood pressure recordings were recruited. BPV was evaluated by standard deviation, coefficient of variation, and variation independent of the mean, respectively. All subjects were followed up to the composite end-point event or until January 15, 2020. Patients were divided into two groups based on 24-h median variation independent of the mean, and demographics, laboratory indicators and echocardiogram results were compared. Logistic regression was used to analyze the risk factors for increased BPV. Multivariate Cox regression and Kaplan-Meier survival analysis were used to explore the relationship between BPV and renal prognosis and major cardiovascular events.ResultsThe mean age was 42.07 ± 12.66 years, with 141 males (57.55%). Multivariate Logistic regression analysis showed that high BMI (OR 1.110, P = 0.017), hyperkalemia (OR 2.227, P = 0.040), increased left ventricular end-diastolic diameter (OR 1.103, P = 0.010) and hypertension (OR 2.525, P = 0.002) were independent risk factors for high BPV. Kaplan-Meier survival analysis showed that renal and cardiovascular outcomes were better in the low BPV group than in the high BPV group (P = 0.006; P = 0.002). After adjusting for age, sex and traditional kidney related risk factors, BPV were not independently associated with renal outcomes. High BPV (HR 4.662, P = 0.017) was the main independent risk factor for major cardiovascular events in CKD.ConclusionsIn non-dialysis CKD, short-term BPV was associated with major cardiovascular disease but not renal progression. BMI, hypertension, potassium balance, and left ventricular end-diastolic diameter influenced short-term BPV.

Older Adults With Higher Blood Pressure Variability Exhibit Cerebrovascular Reactivity Deficits.

Elevated blood pressure (BP) variability is predictive of increased risk for stroke, cerebrovascular disease, and other vascular brain injuries, independent of traditionally studied average BP levels. However, no studies to date have evaluated whether BP variability is related to diminished cerebrovascular reactivity, which may represent an early marker of cerebrovascular dysfunction presaging vascular brain injury. The present study investigated BP variability and cerebrovascular reactivity in a sample of 41 community-dwelling older adults (mean age 69.6 [SD 8.7] years) without a history of dementia or stroke. Short-term BP variability was determined from BP measurements collected continuously during a 5-minute resting period followed by cerebrovascular reactivity during 5-minute hypocapnia and hypercapnia challenge induced by visually guided breathing conditions. Cerebrovascular reactivity was quantified as percent change in cerebral perfusion by pseudo-continuous arterial spin labeling (pCASL)-MRI per unit change in end-tidal CO2. Elevated systolic BP variability was related to lower whole brain cerebrovascular reactivity during hypocapnia (ß = -0.43 [95% CI -0.73, -0.12]; P = 0.008; adjusted R2 =.11) and hypercapnia (ß = -0.42 [95% CI -0.77, -0.06]; P = 0.02; adjusted R2 = 0.19). Findings add to prior work linking BP variability and cerebrovascular disease burden and suggest BP variability may also be related to prodromal markers of cerebrovascular dysfunction and disease, with potential therapeutic implications.