Blood Pressure Variability Parameters Research Articles

Predictors of length of hospital stay and in-hospital adverse events in patients with acute decompensated heart failure: in-hospital 24-hour blood pressure monitoring data

ObjectiveNeurohumoral alterations in heart failure (HF) affect blood pressure variability (BPV) and vascular compliance, but little is known about this subject among patients admitted to the hospital with decompensated HF. This study sought to investigate in-hospital 24-h blood pressure monitoring (HBPM)–derived BPV parameters and vascular compliance in patients with decompensated HF and explore the association of these parameters with hospitalization length and in-hospital adverse events. MethodsA 24-h blood pressure monitor was applied during the first 6 h of admission to the hospital in patients with decompensated HF. Circadian patterns were determined by the study patients. Average real variability (ARV), pulse pressure index (PPI), pulse stiffening ratio (PSR), and ambulatory arterial stiffness index (AASI) values were calculated from HBPM recordings. Admission and discharge N-terminal pro–B-type natriuretic peptide (NT-proBNP) levels, length of hospitalization, and in-hospital adverse events were recorded. ResultsA total of 167 patients with decompensated HF were included in the study. The dipper group exhibited a greater NT-proBNP decrease with the treatment than the non-dipper group and reverse dipper group. Hospitalization length was shorter in the dipper group than in the non-dipper and reverse dipper groups. Although ARV, AASI, and PSR were independently associated with the length of hospitalization, ARV, AASI, and PPI were independently associated with in-hospital adverse events. ConclusionThe post-admission HBPM-derived parameters (dipper pattern, ARV, PPI, PSR, and AASI) of patients admitted to hospital with decompensated HF provide important prognostic information and predict the length of hospital stay.

Blood Pressure Variability is Better Associated with Acute Relative Hyperglycemia Than the Heart Rate Variability in Healthy Young Adults.

Deranged cardiovascular autonomic functions are well-reported complications of diabetes mellitus, where chronic hyperglycemia is an important factor. The role of acute relative hyperglycemia on cardiovascular autonomic functions, particularly on blood pressure variability in healthy subjects, has been rarely explored. Therefore, this study aimed to examine the effect of acute relative hyperglycemia on cardiovascular autonomic functions in healthy young adults. Beat-to-beat blood pressure and electrocardiogram were recorded to assess the heart rate variability and blood pressure variability in 42 young, healthy subjects during fasting and relative hyperglycemic states. Recorded cardiovascular parameters were analyzed in time and frequency domains. Correlations among analyzed parameters of cardiovascular autonomic variabilities were explored during fasting and relative hyperglycemic state. A few of the systolic, mean, and diastolic blood-pressure-variability parameters were significantly altered during acute relative hyperglycemia when compared to the fasting state. However, no significant changes were observed in any of the heart-rate-variability parameters. Also, novel significant correlations were found among many of the parameters of cardiovascular autonomic variabilities during fasting and relative hyperglycemic states. The blood pressure variability is affected significantly during acute relative hyperglycemia in healthy young adults; however, the heart rate variability does not show such changes. Also, many blood pressure variability parameters show significant correlations with heart rate variability and baroreflex sensitivity. It may be hypothesized that although the variabilities in heart rate and blood pressure assess cardiovascular autonomic functions, blood pressure variability is a better indicator of cardiovascular autonomic effects of acute relative hyperglycemia.

A Convolutional Neural Network Classifies Beat-to-Beat Arterial Pressure Spectrograms and Wavelet Transforms according to Age, Sex, and Metabolic State: Novel Frequencies for Cardiovascular Risk Appraisal

Hemodynamic homeostasis is under the control of multiple systems. Continuous blood pressure (BP) time series carry information relevant to the pathophysiological status of the cardiovascular system. Beside average BP, different measures of variability provide prognostic value for distinguishing between cardiovascular risk states. The latter are derived from time- and frequency- domain analysis of BP recordings and are limited by their capacity to provide cumulative risk appraisal among different risk groups. The prediabetic state is associated with cardiovascular risk which is often described to be age- and sex-specific. In this study, we sought to determine distinctive features of continuous arterial pressure (AP) time-series for risk appraisal in a pre-established prediabetic rat model. To overcome the shortcomings associated with conventional BP variability parameters, we trained a convolutional neural network (CNN) using spectrograms and scalograms generated from short-term Fourier- and Morlet wavelet- transforms of AP time series, respectively, from male and female prediabetic rats fed a mild hypercaloric diet for 12- or 24- weeks and their corresponding controls. The CNN consisted of 5 convolutional layers, separated by batch normalization, ReLU activation, and max pooling. The outcome of the fifth convolutional layer had 40% of the data dropped out and delivered to a fully-connected dense layer and then to a softmax function. The data was divided into 80% training, 10% validation, and 10% test sets. The model classified spectrograms and scalograms with test accuracy of 90%+ for the different binary and multi-class classification tasks. On backward propagation of model scores, different salient frequencies were identified as critical features for classification of AP time-series. The identified frequencies were much higher than those typically used in conventional power spectral density (PSD) analysis. Using 3-way ANOVA or principal component analysis for comparison and clustering of the different cardiovascular risk groups of age, sex, and metabolic disease, respectively, according to PSD at the identified peaks does not yield suffcient risk appraisal. This indicates that the CNN possibly captures non-linear relations which are undetectable using inherently linear methods.The results indicate sex- and age-specific patterns of cardiovascular deterioration in prediabetes. Use of artificial intelligence models for the identification of abnormal BP fluctuation patterns can provide suffcient risk appraisal needed for early intervention, particularly in at-risk patients lacking clinical signs of overt cardiovascular disease. None. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The severity of chronic heart failure and the parameters of daily blood pressure profile in patients with coronary heart disease

Aim: Although the prevalence of coronary heart disease (CHD) and hypertension which are the most common causes of the development and progression of chronic heart failure (CHF) is high, 24-hour ambulatory blood pressure (BP) monitoring (ABPM) in patients with CHF is not mandatory to be performed. The growing number of evidence suggests that excessive decrease in BP which clearly reflects increased BP variability (BPV) affects the survival of patients with heart failure (HF). The objective of the study was to investigate the relationship between the parameters specific to CHF severity and features of daily BP profiles in patients with ischemic CHF and hypertension. Methods: Ninety patients with functional class II–IV of CHF and CHD (the main group) and 50 non-CHF patients with hypertension (the comparative group) were examined. The transthoracic echocardiography (TTE) [atrial end-systolic dimension (ESD), ventricular end-diastolic dimension (EDD), left ventricular mass index (LVMI), and left ventricular ejection fraction (LVEF)] and 24-hour ABPM (BPV parameters and proportions of hypotensive episodes) were performed. The relationships between the abovementioned parameters were evaluated using the univariate correlation analysis and stepwise multiple linear regression. Results: Higher functional class of CHF is found to be associated with a higher incidence of daytime systolic BP (SBP) decline and nighttime SBP and diastolic BP (DBP) variability while higher LVEF is related to the hypotensive episodes regardless of CHF. Conclusions: It appears that the larger trials involving CHF patients with reduced LVEF should be conducted to clarify the obtained results.

Obesity in Hypertensive Patients Is Characterized by a Dawn Phenomenon in Systolic Blood Pressure Values and Variability.

One of the causes of hypertension is excess weight gain, which can also affect the course of this disease. Both the diagnosis and management of hypertension commonly use ambulatory blood pressure monitoring; the results of which correlate more strongly with cardiovascular diseases and cardiovascular death than office blood pressure monitoring. We evaluated blood pressure values and their variability from hour to hour to see if and when they differed between hypertensive patients with and without obesity. The study included 1345 patients who underwent 24 h ambulatory blood pressure monitoring and then were divided into groups according to body mass index and waist circumference. The obtained data were analyzed according to the subjects' wake-up time, and short-term blood pressure variability parameters were calculated as the mean of the absolute values of the differences between consecutive measurements. The systolic blood pressure in obese subjects was significantly higher between 1 and 5 h before waking than in normal-weighted individuals. In turn, the variability in systolic and diastolic blood pressure was higher with increasing body mass index. The difference in systolic blood pressure values and blood pressure variability was most prominent in the last 5 h of sleep in obese patients.

Similar Patterns of Dysautonomia in Myalgic Encephalomyelitis/Chronic Fatigue and Post-COVID-19 Syndromes.

There is a considerable overlap between the clinical presentation of post-COVID-19 condition (PCC) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Many of their common symptoms can be linked to dysregulation of the autonomic nervous system (dysautonomia). This study aimed to objectively assess autonomic function in a general group of patients with PCC and in a group of patients with ME/CFS whose disease was not related to COVID-19. We hypothesize that the similarity in the chronic symptoms of patients with PCC and ME/CFS extends to objective autonomic nervous system abnormalities. Synchronous recordings of an electrocardiogram and continuous dynamics of blood pressure in the digital artery using the Penaz method were obtained using the spiroarteriocardiorhythmography method in 34 patients diagnosed with ME/CFS, in whom the onset of the disease was not associated with COVID-19, 29 patients meeting the PCC definition and 32 healthy controls. Heart rate variability (HRV) and systolic and diastolic blood pressure variability (BPV) were assessed at rest and in tests with fixed respiratory rates. Indicators of baroreflex regulation (baroreflex effectiveness index and baroreflex sensitivity) were additionally determined at rest. The total power and power of low-frequency and high-frequency of RR interval variability at rest as well as baroreflex sensitivity were significantly lower both in PCC and ME/CFS patients compared to healthy controls. Several diagnostic prediction models for ME/CFS were developed based on HRV parameters. During slow breathing, the HRV parameters returned to normal in PCC but not in ME/CFS patients. The correlation analysis revealed a close relationship of HRV, BPV parameters and baroreflex sensitivity with fatigue, but not with HADS depressive/anxiety symptoms in the ME/CFS and PCC patients. A similar pattern of HRV and baroreflex failure with signs of a pathological acceleration of age-dependent dysautonomia was identified in the ME/CFS and PCC patients. The clinical, diagnostic and therapeutic implications of these findings are discussed, in light of previously described relationships between inflammation, vascular pathology, atherosclerotic cardiovascular disease and autonomic dysfunction.

Blood pressure variability and outcome in atherosclerosis versus cardioembolism cerebral large vessel occlusion after successful thrombectomy.

Higher blood pressure variability (BPV) has been proven associated with worse functional outcome after endovascular treatment (EVT). However, this association is not established according to different stroke etiologies. In this study, we compared patients with the two highest proportions of stroke etiologies-cardioembolism (CE) and large-artery atherosclerosis (LAA), aiming to explore appropriate strategies of BP management for different etiologies. We enrolled patients with large vessel occlusion (LVO) in anterior circulation who underwent EVT and achieved successful recanalization retrospectively. 24-h blood pressure (BP) and BPV measured as blood pressure reduction (BPr), standard deviation (SD), coefficient of variation (CV), successive variation (SV), average real variability (ARV) after EVT were collected for systolic blood pressure (SBP) and diastolic blood pressure (DBP). The favorable outcome was defined as functional independence by 90-day modified Rankin Scale (mRS 0-2). In our cohort, higher BPV parameters significantly resulted in 90d functional dependence in CE-LVO patients (SBPSV OR: 1.083, 95%CI = 1.009-1.163; SBPARV OR: 1.121, 95%CI = 1.019-1.233; DBPSD OR: 1.124, 95%CI = 1.007-1.1256; DBPCV OR: 1.078, 95%CI = 1.002-1.161). However, for LAA-LVO patients, no positive results correlated 90d functional dependence with 24-hour BPV. Additionally, 90d functional dependence in CE patients with poor collaterals were significantly dependent on post-procedural BPV (DBPmax OR: 1.044, 95%CI = 1.002-1.087; DBPSD OR: 1.229, 95%CI = 1.022-1.1.479; DBPCV OR: 1.143, 95%CI = 1.009-1.295). Whereas to patients with good collaterals, there did not exist such a correlation. In summary, stroke etiologies should probably be taken into consideration to optimize individualized BP management strategies. In order to achieve better clinical outcomes for patients with acute ischemic stroke due to large vessel occlusion, stricter blood pressure management should be taken in cardioembolic stroke patients in contrast with large artery atherosclerotic stroke patients after successful endovascular therapy.

The impact of blood pressure variability on the development of parenchymal hematoma in acute cerebral infarction with atrial fibrillation.

Although blood pressure variability (BPV) and reperfusion are associated with parenchymal hematoma (PH) after stroke, the relationship between BPV and PH in atrial fibrillation (AF) patients who are at risk of reperfusion injury with frequent spontaneous recanalization is unknown. This study aimed to investigate whether BPV within the first 48 h is associated with PH within 72 h in patients with AF and stroke in terms of major vessel occlusion status. A total of 131 patients with AF that were admitted within 24 h after stroke onset were enrolled. PH was defined as a confluent hemorrhage with mass effect. The maximum (max), minimum (min), and average blood pressure (BP) during the first 48 h after admission were calculated. BPV was analyzed by using range between maximum and minimum (max-min), successive variation (SV), standard deviation (SD), and coefficient of variation (CV). All parameters were applied for systemic (SBP), diastolic (DBP), and pulse pressure (PP). After adjusting for confounding variables, various BPV parameters were associated with PH, including SBPmax (p = 0.0426), SBPSV (p = 0.0006), DBPmax-min (p = 0.0437), DBPSV (p = 0.0358), DBPSD (p = 0.0393), PPmax-min (p = 0.0478), PPSV (p < 0.0001), PPSD (p = 0.0034), and PPCV (p = 0.0120). The relationship remained significant in patients with a patent major vessel responsible for infarction but not in patients with an occluded major vessel. In conclusion, this study revealed that high BPV was associated with PH in patients with AF and acute stroke, particularly for those with a patent major vessel. The control of BP and BPV after stroke may be considered in patients with AF.

The relationship between vitamin D and short-term blood pressure variability.

This study aimed to evaluate the relationships between serum levels of 25-hydroxyvitamin D (25(OH)D) and short-term blood pressure variability (BPV) in newly diagnosed hypertensive patients. One hundred newly diagnosed patients with stage one essential hypertension were included and divided into two groups, the deficient and non-deficient groups, according to their 25(OH)D level. The blood pressure was recorded automatically by a portable ambulatory blood pressure monitor for 24 h. In the present study, there was no significant relationship between vitamin D levels and short-term BPV or other parameters derived from ambulatory blood pressure monitoring (ABPM) (P > 0.05). Age (r = 0.260, P = 0.009), serum phosphorus (r = 0.271, P = 0.007), and cholesterol levels (r = 0.310, P = 0.011) were positively correlated with 25(OH)D levels, while glomerular filtration rate (r = -0.232, P = 0.021) negatively correlated with vitamin D levels. There was no crude or adjusted relationship between the levels of 25(OH)D and any parameters of ABPM in multiple linear regression analysis. Although the relationship between vitamin D levels and cardiovascular diseases has been confirmed, vitamin D deficiency does not cause an increase in cardiovascular risk by influencing the short-term BPV or other parameters derived from ABPM.

A STUDY OF BRACHIAL AND CENTRAL 24HOUR BLOOD PRESSURE VARIABILITY ACROSS DIFFERENT HYPERTENSION PHENOTYPES

Objective: Masked hypertensives (MHs) are considered a group of increased cardiovascular risk similar to sustained hypertensives. Brachial short term blood pressure (BP) variability (BPV) has been increasingly related to a higher risk of hypertension-mediated damage. Accordingly, central BP (cBP) has been considered to be more closely associated with target-organ damage. Limited data exists regarding BPV in MHs whereas no study has ever investigated BPV of 24hour cBP in MHs. Therefore, this study aimed to investigate and compare brachial and central BPV measures across different hypertension phenotypes. Design and method: Untreated essential hypertensive patients (UHTs) including MHs and normotensive individuals (NTs) were included in the study. Ambulatory BP was measured with the Mobil-O-Graph device, according to standard guidelines. The BPV parameters including the weighted standard deviation (wSD) and average real variability (ARV) of 24hour brachial and central systolic BP (SBP) and diastolic BP (DBP) were calculated according to a standardized formula based on the ambulatory BP monitoring (ABPM) measurements. Results: A total of 141 participants were studied (49.4±8.6 years; 62.4% males) including 79 UHTs, 22 MHs and 40 NTs. Baseline characteristics were similar between groups. As expected, groups differed significantly in terms of office and ABPM-derived BPs. Remarkably, all markers of 24h brachial BPV and 24h central BPV were comparable between MHs and UHTs and significantly higher compared to NTs (Table 1). Conclusions: Brachial and central BPV parameters in MHs don’t differ compared to UHTs, but are significantly higher compared to NTs. Whether this observation is clinically meaningful in terms of cardiovascular risk and target organ damage prediction, merits further investigation.

Combined Exercise Training Promotes More Benefits on Cardiovascular Autonomic Modulation in Ovariectomized Rats Than Isolated Aerobic or Resistance Training.

Cardiovascular risk increase after ovarian deprivation has been extensively demonstrated by our research group through cardiovascular autonomic analysis. Interventions involving different types of exercises, such as resistance exercises or combined exercises (aerobic and resistance) have been widely recommended to prevent or minimize neuromuscular decline in postmenopausal women, which is aggravated by a sedentary lifestyle. Experimentally, the cardiovascular effects of resistance or combined training, as well as comparison between aerobic, resistance, and combined training, in ovariectomized animals are scarce. In this study, we hypothesized that the combination of aerobic and resistance training may be more effective in preventing muscle mass loss, as well as improving cardiovascular autonomic modulation and baroreflex sensitivity, than aerobic or resistance training individually in ovariectomized rats. Female rats were divided into 5 groups: sedentary (C); ovariectomized (Ovx); trained ovariectomized submitted to aerobic training (OvxAT); resistance training (OvxRT); combined training (OvxCT). Exercise training lasted 8 weeks, with the combined group alternating between aerobic training and resistance training every other day. At the end of the study, glycemia and insulin tolerance were evaluated. Arterial pressure (AP) was directly recorded. Baroreflex sensitivity was assessed by heart rate response to changes in arterial pressure. Cardiovascular autonomic modulation was evaluated by spectral analysis. Combined training was the only training regime that increased baroreflex sensitivity for tachycardic response and reduced all systolic blood pressure variability parameters. Furthermore, all animals submitted to exercise training on a treadmill (OvxAT and OvxCT) presented lower systolic, diastolic, and mean pressure, as well as improvements in the autonomic modulation for the heart. Combined training showed to be more effective than isolated aerobic and resistance training, mixing the isolated benefits of each modality. It was the only modality able to increase baroreflex sensitivity to tachycardic responses, reduce arterial pressure and all parameters of vascular sympathetic modulation.

Effect of small vessel disease severity on blood pressure management after endovascular therapy in the BP TARGET trial.

Acute ischaemic stroke patients with cerebral small vessel disease (CSVD), including cerebral microbleeds (CMBs) and white matter hyperintensities (WMHs), have worse outcomes. The effect was investigated of two blood pressure strategies (intensive vs. standard) and blood pressure variability (BPV) after reperfusion according to CSVD burden in the BP TARGET trial. Patients with available magnetic resonance imaging at baseline were included. CMBs were described as absent or present and WMH severity was described according to the Fazekas classification (0-1, absent-mild; 2-3, moderate to severe). Outcomes consisted of any intracerebral hemorrhage (ICH) at 24 h and favorable outcome at 90 days (modified Rankin Scale score between 0 and 2). In all, 246 patients were included. The intensive systolic blood pressure target was not associated with lower rates of ICH or favorable outcome according to CSVD subgroups (all p values >0.35). Several BPV parameters were associated with increased odds of ICH in patients with CMBs but not in patients without CMBs (diastolic blood pressure coefficient of variation, odds ratio 2.06, 95% confidence interval [CI] 1.13-3.77, in patients with ≥1 CMB vs. 0.94, 95% CI 0.68-1.31, in patients without CMBs, phet =0.026). Several diastolic BPV parameters were associated with worse outcomes in patients with severe WMHs but not in patients without WMHs (diastolic blood pressure coefficient of variation, odds ratio 0.32, 95% CI 0.17-0.61, in patients with severe WMHs vs. 1.09, 95% CI 0.67-1.79, in patients without WMHs; phet =0.003). No effect of the intensive systolic blood pressure management strategy was found on ICH occurrence or functional outcome according to CSVD burden. BPV was associated with higher odds of ICH in patients with CMBs and worse outcome in patients with moderate-to-severe WMHs.

Neuro-Cardio-Autonomic Modulations in Children with Duchenne Muscular Dystrophy.

Duchenne muscular dystrophy (DMD) is a degenerative X-linked muscle disease. Death frequently results from complications in cardiopulmonary systems. Preclinical/early diagnosis of cardiac autonomic abnormalities may aid initiate cardioprotective therapy and enhance prognosis. A cross sectional, prospective study of 38 DMD boys compared with 37 age-matched healthy controls was conducted. Lead II electrocardiography and beat-to-beat blood pressure were recorded to assess heart rate variability (HRV), blood pressure variability (BPV), and baroreceptor sensitivity (BRS) in a standardized environment. Data were analysed and correlated with disease severity and genotype. In the DMD group, the median age at assessment was 8 years [IQR 7-9 years], the median age at disease onset was 3 years [IQR, 2-6 years], and the mean duration of illness was 4 years [IQR, 2.5-5]. DNA sequencing showed deletions in 34/38 (89.5 %) and duplications in 4/38 (10.5%) patients. The median heart rate in DMD children was significantly higher [101.19 (Range, 94.71-108.49)] /min compared to controls [81 (Range, 76.2-92.76)] /min (p < 0.05). All the assessed HRV and BPV parameters were significantly impaired in DMD cases except for the coefficient of variance of systolic blood pressure. Further, BRS parameters were also significantly reduced in DMD, excluding alpha-LF. A positive correlation was found between alpha HF with age at onset and duration of illness. This study demonstrates a distinct early impairment of neuro-cardio-autonomic regulation in DMD. Simple yet effective non-invasive techniques such as HRV, BPV, and BRS may help identify cardiac dysfunction in a pre-clinical state, paving the way for early cardio-protective therapies and limiting disease progression in DMD patients.

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.

APSH-OP-6: ASSOCIATION BETWEEN THE GUT MICROBIOME AND THEIR METABOLITES WITH HUMAN BLOOD PRESSURE VARIABILITY

Objective: Blood pressure (BP) variability is an independent risk factor for cardiovascular events. Recent evidence supports a role for the gut microbiota in BP regulation. However, whether the gut microbiome is associated with BP variability is yet to be determined. Here, we aimed to investigate the interplay between the gut microbiome and their metabolites in relation to three separate parameters of BP variability. Design and method: Ambulatory BP monitoring was performed in 69 participants from two independent sites in Australia (55.1% women; mean ± SD 59.8 ± 7.26-years old, BMI 25.2 ± 2.83 kg/m2). This data was used to determine night-time dipping, morning BP surge (MBPS) and BP variability as standard deviation (SD). The gut microbiome was determined by 16S rRNA sequencing, mRNA expression levels of short-chain fatty acid (SCFA) receptors (FFAR2, FFAR3 and HCAR2) by real-time PCR (qPCR) and metabolite levels by gas chromatography. Results: We identified specific taxa associated with systolic BP variability, night-time dipping and MBPS. Notably, Alistipesfinegoldii and Lactobacillus spp. were only present in participants within the normal ranges of BP variability, MBPS and night-time dipping, while Prevotella spp. and Clostridium spp. were found to be present in extreme dippers and the highest quartiles of BP SD and MBPS. There was a negative association between MBPS and microbial alpha diversity (r = -0.244, P = 0.046). MBPS was also negatively associated with plasma levels of microbial metabolites (SCFAs) (r = -0.305, P = 0.020), particularly acetate (r = -0.311, P = 0.017). We identified a negative correlation between SD data and SCFA receptor FFAR2 mRNA, indicating that participants with higher BP SD had overall lower expression levels of FFAR2 (SD day: r = -0.31, P = 0.039; SD night: r = -0.36, P = 0.016; SD total: r = -0.32, P = 0.035). We also found that participants with a greater percentage in night-time dipping had higher levels of FFAR2 (r = 0.38, P = 0.0087). Conclusions: Gut microbiome diversity, levels of microbial metabolites, and the bacteria Alistipesfinegoldii and Lactobacillus were associated with lower BP variability, whereas a blunted level of SCFA receptor FFAR2 mRNA and Clostridium and Prevotella bacteria were associated with higher BP variability. Our findings suggest the gut microbiome and metabolites may be involved in the regulation of BP variability.

AW-AD-1: SEASONAL VARIATION IN DAY-BY-DAY BLOOD PRESSURE VARIABILITY AND ITS EFFECT ON CARDIOVASCULAR OUTCOMES

Although day-by-day home blood pressure (BP) variability has been associated with cardiovascular disease (CVD) risk, it remains unclear whether this association differs from season to season. The present study aimed to assess seasonal variation in day-by-day home BP variability (BPV) and its association with CVD risk. We analyzed the data from a nationwide, prospective observational study, the J-HOP (Japan Morning Surge-Home Blood Pressure) study, in which 14 consecutive days of home BP monitoring were conducted. The values of standard deviation (SDSBP), coefficient of variation (CVSBP), and average real variability (ARVSBP) of home systolic BP (SBP) were used as indices of day-by-day home BPV. Among 4231 participants (mean age, 64.9 ± 10.9 years, 46.7% male, 91.5% hypertensives), all three day-by-day home BPV indices were lower in summer than winter after adjusting for confounding factors. In winter, SDSBP, CVSBP, and ARVSBP were significantly associated with increased risk of CVD events (coronary artery disease, stroke, heart failure, and aortic dissection) (adjusted HR [95%CI] per 1-SD of SDSBP, 1.27 [1.03, 1.56]; CVSBP, 1.25 [1.03, 1.53]; ARVSBP, 1.44 [1.18, 1.77]). These relationships were also observed in the analysis of quartiles of BPV parameters (adjusted HR [95%CI] compared to the 1st quartile, 4th quartile of SDSBP 2.25 [1.05, 4.81]; CVSBP 2.91 [1.40, 6.03]; ARVSBP 2.71 [1.25, 5.89]). In other seasons, however, there were no significant associations between day-by-day home BPV and CVD event risk. Our findings indicate that day-by-day home BPV measured in winter is more strongly associated with future CVD incidence than that measured in other seasons.

Odnos varijabilnosti arterijskog pritiska iz ambulatornog 24-časovnog monitoringa arterijskog pritiska sa ehokardiografskim parametrima u bolesnika pod antihipertenzivnom terapijom

Introduction: Variability of systolic daytime arterial pressure was until recently a controversial parameter but is now recognized as an independent prognostic risk factor for stroke in hypertensive patients. Blood pressure variability is a quantitative index of spontaneous daily and nocturnal variations in systolic and diastolic arterial blood pressure and has been proposed as a risk factor for inducing subclinical damage to target organs in arterial hypertension. Besides varying degrees of left ventricular myocardial hypertrophy (LVH), patients with hypertension also exhibit accompanying diastolic dysfunction of the left ventricle as an early sign of hypertensive damage, even when myocardial hypertrophy does not develop. The variability of pressure over 24 hours in Ambulatory Blood Pressure Monitoring (ABPM) has not been sufficiently studied in terms of correlation with echocardiographic parameters in controlled hypertension. Methods: A total of 196 adequately treated patients with stage 2 hypertension, with a target of achieving normotension less than 140/90, were examined. The total of 196 patients, 109 males and 87 females, with a mean age of 49.3 ± 8.4 years, untreated or inadequately treated patients with stage 2 hypertension (mean BP before treatment 167/106 mmHg) were divided into three groups according to blood pressure variability parameters. Alongside standard methods: medical history, clinical examination, and electrocardiogram (ECG), 24-hour ambulatory arterial pressure monitoring (ABPM, so-called blood pressure holter) was performed with 24-hour, daytime, and nighttime variability of systolic and diastolic blood pressure as well as Color and Tissue Doppler echocardiography after adequate treatment. Results: Elevated blood pressure variability was observed in 66/196 patients (34%) in group V despite good pressure regulation, while 130/169 (66%) had normal variability - group C (control). A subgroup ExtV was particularly highlighted within group V with extreme variability of daytime systolic BP (SD&gt;20 mmHg) - 15/66 patients (8%). Evaluation of left ventricular myocardial mass index (LVMI) showed no difference in the degree of LVH between groups C and V. In the subgroup ExtV (from group V with extreme blood pressure variability), comprising 15/66 patients (8%), a significant difference in the degree of left ventricular myocardial hypertrophy was found between groups C and V regarding extreme variability (p&lt;0.01). There was no difference concerning gender and age structure. Statistical analysis of investigated 24-hour blood pressure parameters and echocardiographic parameters did not show significant correlation through calculation of the linear correlation coefficient between mean arterial pressure measured by 24-hour ambulatory pressure monitoring and standard deviations of daytime and nighttime pressure and the degree of left ventricular myocardial hypertrophy (linear correlation coefficients r &lt;0.20), as expected. However, there is a moderate but significant correlation between the best echocardiographic parameter of diastolic function, E/E' ratio, and variability of daytime systolic pressure: r= 0.41. Only the subgroup with extreme variability ExtV in terms of daytime systolic pressure has a statistically significant correlation with the degree of LVMI myocardial hypertrophy, r=0.51. Conclusion: One-third of the examined patients, 66/196 patients (34%) in group V, had elevated blood pressure variability despite good pressure regulation. There was no significant difference in the degree of left ventricular myocardial hypertrophy between the investigated parameters of 24-hour blood pressure and echocardiographic indices, except in extreme variability ExtV (P&lt;0.01). However, there is a moderate but significant correlation between the best echocardiographic parameter of diastolic function, E/E' ratio, and variability of daytime systolic pressure: r= 0.41. Only the subgroup with extreme variability ExtV in terms of daytime systolic pressure has a statistically significant correlation with the degree of LVMI myocardial hypertrophy, r=0.51.

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 &gt;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&lt;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&lt;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.

Remote diffusion-weighted imaging lesions and blood pressure variability in primary intracerebral hemorrhage.

ObjectiveThe aim of this study was to examine the association between remote diffusion-weighted imaging lesions (R-DWILs) and blood pressure variability (BPV) in patients with primary intracerebral hemorrhage (ICH).MethodsWe conducted a retrospective review of a consecutive cohort of 375 patients with primary ICH within 24 h onset. R-DWILs were defined as hyperintensity lesions in DWI remote from the hematoma. Blood pressure recordings were extracted up to 24 h post-admission. BPV was measured using SD, coefficient of variation (CV), and successive variation (SV).ResultsRemote DWI lesions were detected in 65 (17.3%) primary ICH patients. In multivariable logistic regression analysis, parameters of BPV were independently associated with R-DWILs, and the results remained consistent after being adjusted with mean SBP. SD, CV, and SV values in the highest quintile, showed 3- to 8-fold increased risk of R-DWILs, compared with the lowest quintile. ΔSBP demonstrated a significant difference in 2 different predictive models. Max SBP only dictated a significant difference in model 1. Mean SBP, admission SBP, and min SBP, failed to present an association with R-DWILs in model 1 or model 2.ConclusionOur results provided additional evidence that BPV is associated with the development of R-DWILs in primary ICH.