Absolute Systolic Blood Pressure Research Articles

Interplay of race and neighborhood deprivation on resting and ambulatory blood pressure in young adults.

Nighttime blood pressure (BP) and BP dipping (daytime-nighttime BP) are prognostic for cardiovascular disease. When compared with other racial/ethnic groups, Black Americans exhibit elevated nighttime BP and attenuated BP dipping. Neighborhood deprivation may contribute to disparities in cardiovascular health, but its effects on resting and ambulatory BP patterns in young adults are unclear. Therefore, we examined associations between neighborhood deprivation with resting and nighttime BP and BP dipping in young Black and White adults. We recruited 19 Black and 28 White participants (23 males/24 females, 21 ± 1 yr, body mass index: 26 ± 4 kg/m2) for 24-h ambulatory BP monitoring. We assessed resting BP, nighttime BP, and BP dipping (absolute dip and nighttime:daytime BP ratio). We used the area deprivation index (ADI) to assess average neighborhood deprivation during early and mid-childhood and adolescence. When compared with White participants, Black participants exhibited higher resting systolic and diastolic BP (Ps ≤ 0.029), nighttime systolic BP (114 ± 9 vs. 108 ± 9 mmHg, P = 0.049), diastolic BP (63 ± 8 vs. 57 ± 7 mmHg, P = 0.010), and attenuated absolute systolic BP dipping (12 ± 5 vs. 9 ± 7 mmHg, P = 0.050). Black participants experienced greater average ADI scores compared with White participants [110 (10) vs. 97 (22), P = 0.002], and select ADI scores correlated with resting BP and some ambulatory BP measures. Within each race, select ADI scores correlated with some BP measures for Black participants, but there were no ADI and BP correlations for White participants. In conclusion, our findings suggest that neighborhood deprivation may contribute to higher resting BP and impaired ambulatory BP patterns in young adults warranting further investigation in larger cohorts.NEW & NOTEWORTHY We demonstrate that young Black adults exhibit higher resting blood pressure, nighttime blood pressure, and attenuated systolic blood pressure dipping compared with young White adults. Black adults were exposed to greater neighborhood deprivation, which demonstrated some associations with resting and ambulatory blood pressure. Our findings add to a growing body of literature indicating that neighborhood deprivation may contribute to increased blood pressure.

Predictors of Hypotension After Angiotensin Receptor-Neprilysin Inhibitor Administration in Patients with Heart Failure.

Angiotensin receptor-neprilysin inhibitors (ARNI) are effective against heart failure (HF) with reduced ejection fraction, but hypotension is a significant complication. Predictors of ARNI-associated hypotension remain unclear. This study aimed to determine predictors of hypotension after administering an ARNI to patients with HF accompanied by ARNI.This retrospective multicenter observational study analyzed data from 138 consecutive patients with HF treated with an ARNI between August 2020 and July 2021. Hypotension attributed to an ARNI after treatment was defined as (A) systolic blood pressure (SBP) below the 1st quartile ≤ 25 mmHg, and as (B) absolute SBP ≤ 103 mmHg. SBP was measured at baseline, after ARNI treatment, at first follow-up as outpatients and on day 7 for inpatients. Presence of atrial fibrillation, and greater BUN/Cr ratio, and SBP at baseline were significant independent predictors for hypotension after ARNI administration on multivariate analyses. Among 43 patients with AF, fine f-waves on electrocardiograms were significantly more prevalent in the hypotensive group.A robust reduction in blood pressure after ARNI administration is associated with AF and elevated BUN/Cr. This highlights the need for caution when administering ARNI to patients with HF.

Dietary Sodium Density and Blood Pressure in Athletes and Non-Athletes in Young Adulthood and Midlife

Current recommendations for the general population limit sodium intake to 2,300 mg/d, however meeting these recommendations may be challenging for athletes, who have greater energy needs. Athletes with greater energy needs are recommended to consume an additional 300-600 mg/h of sodium during prolonged exercise. This recommendation contrasts with guidelines for non-athletes. While the link between sodium and blood pressure (BP) is well-established, studies suggest sodium density, the ratio of sodium to energy consumed, may better predict BP than absolute sodium intake. To our knowledge, no studies have examined these relations in athletes. Hypothesis: We hypothesized that sodium density would be a better indicator of BP when compared to absolute sodium intake and that young athletes would have a higher total sodium intake without a significantly higher BP. Methods: Cross-sectional data were collected from healthy men and women that were stratified into four groups: young collegiate athletes ([YA], n=88, aged 21 ± 2 y), young non-athletes ([YNA], n=36, aged 21 ± 2 y), midlife former collegiate athletes ([MFA], n=82, aged 51 ± 7 y), and midlife non-former athletes ([MNA] n=25, aged 52 ± 7 y). Energy and nutrient intakes were assessed from 3-day dietary records. Anthropometric and BP measurements were collected. Group differences were assessed using a one-way ANOVA with Tukey post-hoc tests. Associations between absolute sodium and sodium density and BP were assessed using Pearson correlations. Results: YA (4102 ± 1490 mg) had a significantly higher sodium intake when compared to YNA (3305 ± 1072 mg), MFA (3159 ± 1154 mg), and MNA (2955 ± 956 mg) (p<0.05 for all). Systolic BP (SBP) was higher in MFA (130 ± 17 mmHg; p<0.05) compared to YA (120 ± 13 mmHg) and YNA (116 ± 13 mmHg). Absolute sodium intake and SBP were positively correlated in YA (r=0.26, p=0.02), YNA (r=0.43, p=0.01) and MFA (r=0.26, p=0.02) but not MNA (r=0.04, p=0.84); however, when corrected for energy intake, these correlations were no longer statistically significant for all groups. Conclusion: These data suggest a weak association between absolute sodium intake and BP in YA. However, when corrected for energy intake this association was no longer present. This may not be specific to YA as this association was also seen in YNA and MFA. Our results highlight the importance of examining both absolute sodium intake and sodium density as it relates to BP in populations with increased energy needs. NIH (DP5 OD031833, R01 HL145055, 2UL1TR001436). 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.

Resting Beat-to-Beat Blood Pressure Variability in Young, Healthy, Non-Hispanic Black Females

Background: Non-Hispanic Black (BL) individuals are at greater risk for cardiovascular disease and hypertension compared to other racial groups. Beat-to-beat blood pressure variability (BPV) is a known predictor of adverse cardiovascular outcomes. Our laboratory recently reported an augmented resting beat-to-beat BPV in non-Hispanic BL males compared to their White (WH) male counterparts. However, racial differences in beat-to-beat BPV between non-Hispanic BL and non-Hispanic WH females are unknown. Therefore, we tested the hypothesis that young, healthy, non-Hispanic BL females have elevated resting beat-to-beat BPV compared to healthy age and body mass index matched WH females. Methods: We studied 12 young healthy non-Hispanic BL females (20 ± 2 years, 25.2 ± 4 kg/m2, mean ± standard deviation) and 12 young healthy non-Hispanic WH females (22 ± 3 years, 22.7 ± 3 kg/m2; P = 0.13 and P = 0.10, respectively). Beat-to-beat arterial blood pressure (finger photoplethysmography) was continuously recorded during ten minutes of supine rest. Mean, standard deviation (SD), range, coeffcient of variation, and average real variability (ARV) were calculated for systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP). Results: Resting absolute SBP (BL: 113 ± 12 mmHg; WH: 112 ± 7 mmHg; P = 0.98), DBP (BL: 69 ± 7 mmHg; WH: 66 ± 5 mmHg; P = 0.22), and MAP (BL: 83 ± 7 mmHg; WH: 81 ± 4 mmHg; P = 0.48) were not different between groups. Likewise, beat-to-beat SBP SD (BL: 3.5 ± 0.78 mmHg; WH: 4.0 ± 1.16 mmHg; P = 0.21), range (BL: 21 ± 5 mmHg; WH: 24 ± 6 mmHg; P = 0.26), coeffcient of variation (BL: 3.01 ± 0.82%; WH: 3.56 ± 0.96%; P = 0.20), and ARV (BL: 2.02 ± 0.46; WH: 2.26 ± 0.6; P = 0.27) were not different between BL and WH females. There were also no differences in any of the beat-to-beat BPV measures for DBP or MAP between BL and WH females (all P > 0.05). Conclusion: In contrast to our hypothesis and previous work in non-Hispanic BL males, these preliminary data suggest that beat-to-beat BPV is not different between non-Hispanic BL and WH females. This work was supported by the College of Nursing and Health Innovation. 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.

Comparison of Postexercise Ankle Brachial Index in at Risk versus Diagnosed Peripheral Arterial Disease Population

Abstract Background: Peripheral arterial disease (PAD) is characterized by stenosis or occlusion in the arteries of the limb causing limitation in the distal blood flow. Out of the various risk factors identified, diabetes and cigarette smoking are the strongest predictors of PAD. PAD results from atherosclerosis of the vessel wall. Patients with lower extremity PAD have clinical presentation of intermittent claudication and atypical leg pain. In patients with arterial stenosis, there is a drop in pressure and flow across stenosis. Asymptomatic PAD approximately 20%–50% of total patients diagnosed with PAD. Ankle brachial index (ABI) is clinically widely used modality which helps to identify the disease. ABI test is the ratio of systolic ankle blood pressure and highest systolic brachial blood pressure. Population at risk with normal resting ABI may still have PAD. For such population, postexercise ABI is recommended. This study evaluated and compared ABI postexercise in normal healthy individuals without risk of PAD, at risk of PAD. Materials and Methods: This study is an observational study. Population with age more than 35 years were selected. Framingham Risk Score was taken for normal and at-risk population. Subjects were recruited in three groups: A, B, and C. ABI at rest was assessed. Individuals performed exercise treadmill test. Immediately, after completing the exercise, postexercise ABI was taken. Absolute systolic blood pressure values and postexercise ABI values were obtained in all three groups and then were compared. Data were analyzed using the SPSS software version 26. Results: The results of this study showed that for all the three groups, there was a significant difference in ABI at rest, postexercise ABI, and difference in systolic ankle pressure as P value was <0.001. When the Chi-squared test was done for postexercise ABI and postsystolic ankle pressure in between Group B and Group C, there was no significant difference found as the P value was >0.05. Conclusion: On comparison with at risk and normal individuals, no significant difference was found in terms of postexercise ABI and change in systolic ankle pressure.

Effect of carotid corrected flow time combined with perioperative fluid therapy on preventing hypotension after general anesthesia induction in elderly patients: a prospective cohort study.

Hypotension often occurs following the induction of general anesthesia in elderly patients undergoing surgery and can lead to severe complications. This study assessed the effect of carotid corrected flow time (FTc) combined with perioperative fluid therapy on preventing hypotension after general anesthesia induction in elderly patients. The prospective cohort study was divided into two parts. The first part (Part I) consisted of 112 elderly patients. Carotid FTc was measured using Color Doppler Ultrasound 5min before anesthesia induction. Hypotension was defined as a decrease of greater than 30% in systolic blood pressure (SBP) or a decrease of greater than 20% in mean arterial pressure (MAP) from baseline, or an absolute SBP below 90mmHg and MAP below 60mmHg within 3min after induction of general anesthesia. The predictive value of carotid FTc was determined using receiver operating characteristic (ROC) curve. The second part (Part II) consisted of 65 elderly patients. Based on the results in Part I, elderly patients with carotid FTc below the optimal cut-off value received perioperative fluid therapy at a volume of 8ml/kg of balanced crystalloids (lactated Ringer's solution) in 30min before induction. The effect of carotid FTc combined with perioperative fluid therapy was assessed by comparing observed incidence of hypotension after induction. The area under the ROC for carotid FTc to predict hypotension after induction was 0.876 [95% confidence interval (CI) 0.800-0.952, P <0.001]. The optimal cut-off value was 334.95ms (sensitivity of 87.20%; specificity of 82.20%). The logistic regression analysis revealed that carotid FTc is an independent predictor for post-induction hypotension in elderly patients. The incidence of post-induction hypotension was significantly lower ( P <0.001) in patients with carotid FTc less than 334.95ms who received perioperative fluid therapy (35.71%) compared to those who did not (92.31%). Carotid FTc combined with the perioperative fluid therapy could significantly reduce the incidence of hypotension after the induction of general anesthesia in elderly patients.

Blood Pressure and Hematoma Expansion in Hemorrhagic Stroke

IntroductionHematoma expansion after hemorrhagic stroke can lead to devastating consequences. An important factor associated with this is high blood pressure. This study was carried out to find out what proportion of patients with hemorrhagic stroke develop hematoma expansion and whether blood pressure during presentation could be associated with it.MethodsThis prospective observational study was carried out over a period of one year in patients who were admitted with the diagnosis of hemorrhagic stroke. The collected data were entered into and analyzed by using the Statistical Package for the Social Sciences version 26 after obtaining approval from the Institutional Review Committee of the Institute of Medicine, Tribhuvan University. ResultsOut of 83 patients included in the study, history of hypertension was present in 72 (86.7%). Hematoma expansion occurred in 11 (13.3%). There was no statistically significant associations between mean systolic, diastolic, and mean blood pressures between patients with and without hematoma expansion [(168.9±35.6, 164.5±28.5, t(81)=0.47, p=0.64), (101.8±18.9, 101.2±19.6, t(81)=0.10, p=0.92) and (124.2±23.6, 122.3±21.5, t(81)=0.27, p=0.79) respectively (values in mmHg)]. Majority of patients with hematoma expansion had high absolute systolic blood pressure (27.3% vs 26.4%) and high absolute diastolic blood pressure (54.5% vs 38.9%); however, the associations were not statistically significant (p= 1.00 and 0.33 respectively).Conclusions High blood pressure is highly prevalent but hematoma expansion is not common in patients with hemorrhagic stroke. There was no statistically significant association between history of hypertension, gender, patient age, absolute and mean blood pressures, and hematoma expansion in our study.

Abnormal workload-indexed blood pressure response to exercise in patients at risk of or with overt heart failure

Abstract Background Conflicting evidence exists regarding the functional and prognostic significance of hypertensive response to exercise (HRE), commonly defined as peak systolic blood pressure (SBP) &amp;gt;210 mmHg in males and &amp;gt;190 mmHg in females. No study yet has explored the impact of sex-specific, workload-indexed HRE in patients at different stages of the heart failure (HF) spectrum, as defined by the American College of Cardiology/American Heart Association HF staging system. Purpose We evaluated the SBP/Workload slope during exercise across the HF spectrum and investigated the hemodynamic, functional and prognostic correlates of HRE. Methods Fifty-eight healthy controls, 201 subjects at risk of developing HF (HF Stages A-B), and 369 patients with a definite diagnosis of HF (Stage C) were enrolled; among the latter, 143 had preserved (HFpEF) and 226 reduced (HFrEF) left ventricular ejection fraction. All patients underwent a combined cardiopulmonary-exercise stress echocardiography test. For each patient, we recorded at least two BP measurements during exercise: the first within the first minute of exercise and the last at peak effort. The SBP/Workload slope was calculated as the difference in SBP over the corresponding increment in watts (W): (SBPpeak – SBPfirst)/(Wpeak – Wfirst). In each ACC/AHA HF Stage, we divided patients according to SBP/Workload slope tertiles; HRE was defined as the highest sex-specific SBP/Workload slope tertile. A composite of all-cause mortality and hospitalization for cardiovascular reasons was chosen as the primary outcome. Results The median SBP/Workload slope was 0.53 (interquartile range 0.36-0.72) mmHg/W and was steeper in women than in men in all subgroups (p&amp;lt;0.0001). After adjusting for age and sex, SBP/Workload slope was significantly higher in Stages A-B (0.61, 0.47-0.75 mmHg/W) and HFpEF (0.63, 0.42-0.86 mmHg/W) compared to controls (0.43, 0.35-0.57 mmHg/W) and HFrEF (0.47, 0.30-0.63 mmHg/W, Figure 1). In all subgroups, patients with HRE showed significantly lower peak oxygen consumption and peripheral oxygen extraction (Table). After a median follow-up of 16 months, HRE was an independent predictor of adverse outcomes (Hazard Ratio 2.05, 95% confidence interval 1.81-5.18), while rest and peak absolute SBP values did not. Kaplan-Meier analysis confirmed a worse survival probability for patients with HRE in Stages A-B and HFpEF but not in HFrEF. After adjusting for confounding factors, the patients with the highest SBP/Workload slope had a 47% higher risk of the primary outcome than subjects in the lowest tertile (Figure 2). Conclusions Across the HF spectrum, patients with HRE, as evaluated by the SBP/Workload slope, present with peculiar pathophysiological features and impaired functional capacity. This is especially true for those in Stages A-B and patients with HFpEF. In these subgroups, HRE may portend an increased risk of adverse cardiovascular outcomes.SBP/workload slopesKaplan-Meier curves and Hazard Ratios

Impact of frequent intradialytic hypotension on quality of life in patients undergoing hemodialysis

BackgroundIntradialytic hypotension (IDH) is frequently accompanied by symptoms of nausea, dizziness, fatigue, muscle spasm, and arrhythmia, which can adversely impact the daily lives of patients who undergo hemodialysis and may lead to decreased quality of life (QoL). This study employed the KDQOL™-36 scale to evaluate the impact of frequent IDH, based on the definition determined by predialysis blood pressure (BP) and nadir systolic blood pressure (SBP) thresholds, on the QoL of patients.MethodsThis is a single center retrospective cohort study involving 160 hemodialysis patients. We enrolled adult patients with uremia who received routine hemodialysis (4 h/time, 3 times/week) from October 1, 2019, to September 30, 2021. Frequent IDH was defined as an absolute nadir SBP < 90 mmHg occurring in no less than 30% of hemodialysis sessions when predialysis SBP < 159 mmHg (or < 100 mmHg when predialysis BP ≥ 160 mmHg).The differences between patients with and without frequent IDH were compared using the independent t test, Kruskal‒Wallis test, or chi-square test. The primary visit was at month 36, and the remaining visits were exploratory outcomes.ResultsCompared to patients with infrequent IDH at baseline, those with frequent IDH had significantly lower scores on the symptoms and discomfort of kidney disease dimension at all follow-up points (P < 0.05). The symptoms and discomfort of kidney disease dimension were worse in patients with frequent IDH. Those with frequent IDH had a significantly poorer QoL regarding the dimensions of symptoms and discomfort of kidney disease and the impact of kidney disease on life.ConclusionsThe findings of the study suggest an association between frequent IDH and QoL dimensions of symptoms and discomfort of kidney disease and the impact of kidney disease on life dimension under the definition of frequent IDH.

Additive influence of exercise pressor reflex activation on Valsalva responses in white and black adults.

This study aimed to determine if activation of the exercise pressor reflex exerts additive or redundant influences on the autonomic responses to the Valsalva maneuver (VL), and if these responses differ between White and Black or African American (B/AA) individuals. Twenty participants (B/AA n = 10, White n = 10) performed three separate experimental trials. In the first trial, participants performed two VLs in a resting condition. In a second trial, participants performed 5min of continuous handgrip (HG) exercise at 35% of the predetermined maximal voluntary contraction. In a third and final trial, participants repeated the 5-min bout of HG while also performing two VLs during the 4th and 5th minutes. Beat by beat blood pressure and heart rate (HR) were recorded continuously and the absolute systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse pressure (PP), and heart rate (HR) responses were reported for phases I-IV of each VL. No significant group by trial interactions or main effects of group were observed for any phase of the VL (all p ≥ 0.36). However, significant main effects of time were observed for blood pressure and heart rate during phases IIa-IV (all p ≤ 0.02). Specifically, the addition of HG exercise exaggerated the hypertensive responses during phases IIb and IV (all p ≤ 0.04) and blunted the hypotensive responses during phases IIa and III (all p ≤ 0.01). These results suggest that activation of the exercise pressor reflex exerts an additive influence on autonomic responses to the VL maneuver in both White and B/AA adults.

Exercise systolic blood pressure indexed to work rate predicts future risk of incident stroke

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): 1) The CircM network, Linköping University 2) The Swedish Stroke Association. Background Hypertension is a major risk factor for stroke. Exaggerated peak systolic blood pressure (SBP) during exercise is associated with increased risk of hypertension in normotensive subjects, whereas low, rather than high, peak exercise SBP predicts cardiovascular and all-cause mortality. Purpose We aimed to study the risk of incident fatal and non-fatal stroke in relation to absolute and work rate indexed exercise SBP, in patients referred for exercise testing. Methods We cross-linked clinical data from 14,428 bicycle ergometer exercise tests with data from the National Patient Registry and the Registry of Prescribed Medications up until December 2019. Subjects with a history of cerebrovascular disease were excluded, as well as subjects with submaximal tests, a drop in SBP during exercise, or with missing SBP data at the end of exercise. Baseline comorbidity was defined as diagnosis of, or treatment for, hypertension, diabetes, hyperlipidemia, and coronary artery disease (CAD). Work rate indexed SBP response (SBP/Watt-slope) was calculated as the increase in SBP during exercise divided by the increase in work rate. We applied Cox regression to calculate hazard ratios (HR) with 95% confidence intervals (95% CI) for the risk of incident stroke in association to peak SBP and the SBP/Watt-slope. We used absolute values as well the upper limit of normal (≥2 Z scores) of a recently published reference population, with reference equation including age, sex, SBP at rest, Wmax (for SBP peak only) and height (for SBP/W-slope only). Analyses were adjusted for age, sex, and baseline comorbidity. Results In total, 7,946 subjects (54% male, age 55±13 years) were included, with baseline comorbidity of hypertension (28%), diabetes (7%), hyperlipidemia (16%), and CAD (13%). During a median follow-up of 8.4 years (inter quartile range 5.8-11.5), 3.1% developed ischemic (2.2%) or hemorrhagic (1.0%) stroke. There were positive associations to future stroke with absolute peak exercise SBP (HR: 1.08 [1.03 – 1.13] per 10 mmHg increase) and with SBP/Watt-slope (HR: 1.09 [1.05 – 1.14] per 1 mmHg/10 Watt increase), but not after adjustment for sex, age and baseline comorbidity. However, having a SBP/Watt-slope ≥2 Z scores was associated with an increased risk for stroke (HR: 1.56 [1.08 – 2.25)] after adjustment for baseline comorbidity, whereas an adjusted SBP peak ≥2 Z scores was not (HR: 0.62 [0.32 – 1.21]). Conclusion A workload-indexed SBP response (SBP/Watt-slope) above the upper limit of normal may help to identify subjects with no history of cerebrovascular disease at risk of future stroke. In contrast, the absolute exercise SBP response to exercise does not add substantial information to the risk estimation above age, sex, and baseline comorbidity.

Beat-to-beat resting blood pressure variability in patients with type 2 diabetes: effect of statin therapy

Type 2 diabetes (T2D) is a major health concern affecting more than 30 million people in the United States alone. Approximately two-thirds of patients with T2D develop hypertension, a major risk factor for cardiovascular disease. In addition to higher resting absolute blood pressure (BP), increased variability in BP has also been related to greater cardiovascular disease risk. However, whether patients with T2D display greater beat-to-beat BP variability remains unknown. Herein, we hypothesized that patients with T2D would exhibit greater beat-to-beat BP variability than age and body-weight-matched control subjects. In addition, since previous literature has shown that statins lower cardiovascular disease risk through favorable pleiotropic mechanisms, we further hypothesized that patients with T2D taking statins (T2D+statin) would have a lower beat-to-beat BP variability compared to patients with T2D not taking statins (T2D-statin). Beat-to-beat BP (finger photoplethysmography) and heart rate (ECG) were continuously measured, and absolute BP (automated sphygmomanometer) was measured periodically in patients with T2D (N=23; T2D+statin: N=10, T2D-statin: N=13) and age and body weight-matched control subjects (N=17). Measurements were made over the course of a quiet resting baseline period (9.5±1.3 minutes) with subjects in a supine position. Beat-to-beat BP variability was quantified as standard deviation (SD), range, and average real variability (average change in BP from one heartbeat to the next). Data are presented as mean ± standard deviation. Resting absolute systolic BP, diastolic BP, and mean arterial pressure (MAP) were not different between control subjects and T2D patients (P&gt;0.05 for all). There was also no difference in beat-to-beat systolic BP, diastolic BP, or MAP variability between the groups (e.g., MAP SD: control: 4.5±1.3 mmHg, T2D: 4.7±1.1 mmHg, P=0.763). When comparing T2D patients taking statins and those not taking statins, no difference was observed in absolute resting BP (P&gt;0.05). Likewise, systolic BP variability was not different between groups (SD: T2D-statin: 7.0±2.2 mmHg, T2D+statin: 6.3±1.4 mmHg, P=0.369). However, diastolic BP variability was significantly higher in T2D-statin patients (SD: T2D-statin: 4.1±1.1 mmHg, T2D+statin: 3.1±0.6 mmHg, P=0.013) and MAP variability tended to be higher (SD: T2D-statin: 5.2±1.4 mmHg, T2D+statin: 4.3±0.7 mmHg, P=0.061). Similar results were found for BP range and average real variability. These preliminary findings suggest that statin therapy may have a beneficial effect in lowering BP variability in patients with T2D. Supported by American Heart Association (AHA) - Institutional Award for Undergraduate Student Training - #915555. This is the full abstract presented at the American Physiology Summit 2023 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.

Deep phenotype characterization of hypertensive response to exercise: implications on functional capacity and prognosis across the heart failure spectrum

Limited evidence is available regarding the role of hypertensive response to exercise (HRE) in heart failure (HF). We evaluated the systolic blood pressure (SBP) to workload slope during exercise across the HF spectrum, investigating haemodynamic and prognostic correlates of HRE. We prospectively enrolled 369 patients with HF Stage C (143 had preserved [HFpEF], and 226 reduced [HFrEF] ejection fraction), 201 subjects at risk of developing HF (HF Stages A-B), and 58 healthy controls. We performed a combined cardiopulmonary exercise stress echocardiography testing. We defined HRE as the highest sex-specific SBP/workload slope tertile in each HF stage. Median SBP/workload slope was 0.53 mmHg/W (interquartile range 0.36-0.72); the slope was 39% steeper in women than men (p < 0.0001). After adjusting for age and sex, SBP/workload slope in HFrEF (0.47, 0.30-0.63) was similar to controls (0.43, 0.35-0.57) but significantly lower than Stages A-B (0.61, 0.47-0.75) and HFpEF (0.63, 0.42-0.86). Patients with HRE showed significantly lower peak oxygen consumption and peripheral oxygen extraction. After a median follow-up of 16 months, HRE was independently associated with adverse outcomes (all-cause mortality and hospitalization for cardiovascular reasons: hazard ratio 2.05, 95% confidence interval 1.81-5.18), while rest and peak SBP were not. Kaplan-Meier analysis confirmed a worse survival probability in Stages A-B (p=0.005) and HFpEF (p < 0.001), but not HFrEF. A steeper SBP/workload slope is associated with impaired functional capacity across the HF spectrum and could be a more sensitive predictor of adverse events than absolute SBP values, mainly in patients in Stages A-B and HFpEF.

Prediction of Intradialytic Blood Pressure Variation Based on Big Data

Introduction: Cardiovascular (CV) events are the major cause of morbidity and mortality associated with blood pressure (BP) in hemodialysis (HD) patients. BP varies significantly during HD treatment, and the dramatic variation in BP is a well-recognized risk factor for increased mortality. The development of an intelligent system capable of predicting BP profiles for real-time monitoring is important. Our aim was to build a web-based system to predict changes in systolic BP (SBP) during HD. Methods: In this study, dialysis equipment connected to the Vital Info Portal gateway collected HD parameters that were linked to demographic data stored in the hospital information system. There were 3 types of patients: training, test, and new. A multiple linear regression model was built using the training group with SBP change as the dependent variable and dialysis parameters as the independent variables. We tested the model’s performance on test and new patient groups using coverage rates with different thresholds. The model’s performance was visualized using a web-based interactive system. Results: A total of 542,424 BP records were used for model building. The accuracy was greater than 80% in the prediction error range of 15%, and 20 mm Hg of true SBP in the test and new patient groups for the model of SBP changes suggested the good performance of our prediction model. In the analysis of absolute SBP values (5, 10, 15, 20, and 25 mm Hg), the accuracy of the SBP prediction increased as the threshold value increased. Discussion: This databae supported our prediction model in reducing the frequency of intradialytic SBP variability, which may help in clinical decision-making when a new patient receives HD treatment. Further investigations are needed to determine whether the introduction of the intelligent SBP prediction system decreases the incidence of CV events in HD patients.

Beat-to-Beat Blood Pressure Estimation by Photoplethysmography and Its Interpretation

Blood pressure (BP) is among the most important vital signals. Estimation of absolute BP solely using photoplethysmography (PPG) has gained immense attention over the last years. Available works differ in terms of used features as well as classifiers and bear large differences in their results. This work aims to provide a machine learning method for absolute BP estimation, its interpretation using computational methods and its critical appraisal in face of the current literature. We used data from three different sources including 273 subjects and 259,986 single beats. We extracted multiple features from PPG signals and its derivatives. BP was estimated by xgboost regression. For interpretation we used Shapley additive values (SHAP). Absolute systolic BP estimation using a strict separation of subjects yielded a mean absolute error of and correlation of . The results markedly improve if data separation is changed (MAE: , r: ). Interpretation by means of SHAP revealed four features from PPG, its derivation and its decomposition to be most relevant. The presented approach depicts a general way to interpret multivariate prediction algorithms and reveals certain features to be valuable for absolute BP estimation. Our work underlines the considerable impact of data selection and of training/testing separation, which must be considered in detail when algorithms are to be compared. In order to make our work traceable, we have made all methods available to the public.

Blood Pressure Variability Indices for Outcome Prediction After Thrombectomy in Stroke by Using High-Resolution Data

BackgroundBlood pressure variability (BPV) is associated with outcome after endovascular thrombectomy in acute large vessel occlusion stroke. We aimed to provide the optimal sampling frequency and BPV index for outcome prediction by using high-resolution blood pressure (BP) data.MethodsPatient characteristics, 3-month outcome, and BP values measured intraarterially at 1 Hz for up to 24 h were extracted from 34 patients treated at a tertiary care center neurocritical care unit. Outcome was dichotomized (modified Rankin Scale 0–2, favorable, and 3–6, unfavorable) and associated with systolic BPV (as calculated by using standard deviation, coefficient of variation, averaged real variability, successive variation, number of trend changes, and a spectral approach using the power of specific BP frequencies). BP values were downsampled by either averaging or omitting all BP values within each prespecified time bin to compare the different sampling rates.ResultsOut of 34 patients (age 72 ± 12.7 years, 67.6% men), 10 (29.4%) achieved a favorable functional outcome and 24 (70.6%) had an unfavorable functional outcome at 3 months. No group differences were found in mean absolute systolic BP (SBP) (130 ± 18 mm Hg, p = 0.82) and diastolic BP (DBP) (59 ± 10 mm Hg, p = 1.00) during the monitoring time. BPV only reached predictive significance when using successive variation extracted from downsampled (averaged over 5 min) SBP data (median 4.8 mm Hg [range 3.8–7.1]) in patients with favorable versus 7.1 mmHg [range 5.5–9.7] in those with unfavorable outcome, area under the curve = 0.74 [confidence interval (CI) 0.57–0.85; p = 0.031], or the power of midrange frequencies between 1/20 and 1/5 min [area under the curve = 0.75 (CI 0.59–0.86), p = 0.020].ConclusionsUsing high-resolution BP data of 1 Hz, downsampling by averaging all BP values within 5-min intervals is essential to find relevant differences in systolic BPV, as noise can be avoided (confirmed by the significance of the power of midrange frequencies). These results demonstrate how high-resolution BP data can be processed for effective outcome prediction.

Immediate post-exercise blood pressure and arterial stiffness in hypertensive and normotensive older females.

Although it has been suggested that increased arterial stiffness is linked to exaggerated blood pressure (BP) from brief moderate exercise, it is not clear whether this occurs in older adults with and without hypertension. This study investigates whether the immediate post‐exercise systolic BP following brief moderate exercise is associated with arterial stiffness in older females with different BP status. This cross‐sectional study included 191 older females aged 60–80 years without known cardiovascular disease (CVD). Arterial stiffness was determined by aortic pulse wave velocity (aPWV). Systolic BP was measured before and immediately following a 3‐min moderate walking test (stage 1 Bruce protocol). Specific quartile‐based thresholds were used to define an exaggerated immediate post‐exercise systolic BP for hypertensive and normotensive older females (quartile 4 as an exaggerated response). Traditional CVD risk factors were assessed (covariates). Older females from the highest quartile of immediate post‐exercise absolute systolic BP showed higher aPWV compared to their peers from the lowest quartile (β = .22 m/s, p = .018). The quartile‐based threshold to define the exaggerated post‐exercise systolic BP was higher in hypertensive than in normotensive older females (174 vs. 172 mmHg). In summary, exaggerated immediate post‐exercise systolic BP following a brief moderate exercise is associated with higher arterial stiffness in older females with different BP status.

Visit-to-visit blood pressure variability and the risk of stroke in the Netherlands: A population-based cohort study.

BackgroundApart from blood pressure level itself, variation in blood pressure has been implicated in the development of stroke in subgroups at high cardiovascular risk. We determined the association between visit-to-visit blood pressure variability and stroke risk in the general population, taking into account the size and direction of variation and several time intervals prior to stroke diagnosis.Methods and findingsFrom 1990 to 2016, we included 9,958 stroke-free participants of the population-based Rotterdam Study in the Netherlands. This is a prospective cohort study including participants aged 45 years and older. Systolic blood pressure (SBP) variability was calculated as absolute SBP difference divided by mean SBP over 2 sequential visits (median 4.6 years apart). Directional SBP variability was defined as SBP difference over 2 visits divided by mean SBP. Using time-varying Cox proportional hazards models adjusted for age, sex, mean SBP, and cardiovascular risk factors, hazard ratios (HRs) for stroke up to January 2016 were estimated per SD increase and in tertiles of variability. We also conducted analyses with 3-, 6-, and 9-year intervals between variability measurement and stroke assessment. These analyses were repeated for diastolic blood pressure (DBP). The mean age of the study population was 67.4 ± 8.2 years and 5,776 (58.0%) were women. During a median follow-up of 10.1 years, 971 (9.8%) participants had a stroke, including 641 ischemic, 89 hemorrhagic, and 241 unspecified strokes. SBP variability was associated with an increased risk of hemorrhagic stroke (HR per SD 1.27, 95% CI 1.05–1.54, p = 0.02) and unspecified stroke (HR per SD 1.21, 95% CI 1.09–1.34, p < 0.001). The associations were stronger for all stroke subtypes with longer time intervals; the HR for any stroke was 1.29 (95% CI 1.21–1.36, p < 0.001) at 3 years, 1.47 (95% CI 1.35–1.59, p < 0.001) at 6 years, and 1.38 (95%CI 1.24–1.51, p < 0.001) at 9 years. For DBP variability, we found an association with unspecified stroke risk. Both the rise and fall of SBP and the fall of DBP were associated with an increased risk for unspecified stroke. Limitations of the study include that, due to an average interval of 4 years between visits, our findings may not be generalizable to blood pressure variability over shorter periods.ConclusionsIn this population-based study, we found that visit-to-visit blood pressure variation was associated with an increased risk of unspecified and hemorrhagic stroke, independent of direction of variation or mean blood pressure.

Haemodynamic effects of a prehospital emergency anaesthesia protocol consisting of fentanyl, ketamine and rocuronium in patients with trauma: a retrospective analysis of data from a Helicopter Emergency Medical Service

ObjectivesPrehospital rapid sequence induction (RSI) of anaesthesia is an intervention with significant associated risk. In this study, we aimed to investigate the haemodynamic response over time of a prehospital RSI...

A randomized controlled trial of two dialysate sodium concentrations in hospitalized hemodialysis patients.

Several large dialysis organizations have lowered the dialysate sodium concentration (DNa) in an effort to ameliorate hypervolemia. The implications of lower DNa on intra-dialytic hypotension (IDH) during hospitalizations of hemodialysis (HD) patients is unclear. In this double-blind, single center, randomized controlled trial (RCT), hospitalized maintenance HD patients were randomized to receive higher (142 mmol/L) or lower (138 mmol/L) DNa for up to six sessions. Blood pressure (BP) was measured in a standardized fashion pre-HD, post-HD and every 15 min during HD. The endpoints were: (i) the average decline in systolic BP (pre-HD minus lowest intra-HD, primary endpoint) and (ii) the proportion of total sessions complicated by IDH (drop of ≥20 mmHg from the pre-HD systolic BP, secondary endpoint). A total of 139 patients completed the trial, contributing 311 study visits. There were no significant differences in the average systolic blood pressure (SBP) decline between the higher and lower DNa groups (23 ± 16 versus 26 ± 16 mmHg; P = 0.57). The proportion of total sessions complicated by IDH was similar in the higher DNa group, compared with the lower DNa group [54% versus 59%; odds ratio 0.72; 95% confidence interval (95% CI) 0.36-1.44; P = 0.35]. In post hoc analyses adjusting for imbalances in baseline characteristics, higher DNa was associated with 8 mmHg (95% CI 2-13 mmHg) less decline in SBP, compared with lower DNa. Patient symptoms and adverse events were similar between the groups. In this RCT for hospitalized maintenance of HD patients, we found no difference in the absolute SBP decline between those who received higher versus lower DNa in intention-to-treat analyses. Post hoc adjusted analyses suggested a lower risk of IDH with higher DNa; thus, larger, multi-center studies to confirm these findings are warranted.