Noninvasive Blood Pressure Monitor Designed for Patients With Heart Failure Supported with Continuous-Flow Left Ventricular Assist Devices.
ABSTRACT: The gold standard for noninvasive blood pressure (BP) measurement, the Doppler technique, does not provide systolic blood pressure (SBP) and diastolic blood pressure (DBP) and may limit therapy outcomes. To improve patient care, we tested specifically designed experimental BP (ExpBP) monitor and the Doppler technique by comparing noninvasive measures to the intraarterial (I-A) BP in 31 patients with end-stage heart failure (4 females) 2.6?±?3.4 days post-LVAD implantation (20 HeartMate II and 11 HeartWare). Bland-Altman plots revealed that the ExpBP monitor overestimated mean arterial pressure (MAP) by 1.2 (4.8) mm Hg (mean difference [standard deviation]), whereas the Doppler by 6.7 (5.8) mm Hg. The ExpBP SBP was overestimated by 0.8 (6.1) mm Hg and DBP by 1.9 (5.3) mm Hg compared with the respective I-A pressures. Both techniques achieved similar measurement reliability. In the measurement "success rate" expressed as a frequency (percent) of readable BP values per measurement attempts, Doppler accomplished 100% vs. 97%, 97%, and 94% of successful detections of MAP, SBP, and DBP provided by the ExpBP monitor. The ExpBP monitor demonstrated higher accuracy in the MAP assessment than the Doppler in addition to providing SBP and DBP in majority of subjects. Improved BP control may help to mitigate related neurologic adverse event rates.
Project description:<h4>Background</h4> The intermittent measurement of blood pressure (BP) remains the standard of care during anesthesia or procedural sedation. To improve the early identification of hemodynamic compromise, various noninvasive BP devices have been developed which provide a continuous BP reading. The current study evaluates the accuracy of a novel continuous BP device, the NICCI system, in adolescents weighing 40 - 80 kg. <h4>Methods</h4> During intraoperative anesthetic care, BP readings (systolic, diastolic, and mean) were captured from the arterial cannula and the NICCI device every second. <h4>Results</h4> The study cohort included 44 pediatric patients undergoing major orthopedic, cardiac, and neurosurgical procedures. A total of 383,126 pairs of systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) values from the arterial cannula and the NICCI device were analyzed. The absolute difference for SBP, DBP, and MAP values from the NICCI monitor and the arterial cannula were 10 ± 8, 9 ± 7, and 9 ± 7 mm Hg, respectively. The difference between the BP values from the NICCI and the arterial cannula was ≤ 10 mm Hg for 60% of the SBP readings, 67% of the DBP readings, and 56% of the MAP readings. Using Bland-Altman analysis, the bias was 2, 3, and 4 mm Hg for the SBP, DBP, and MAP. <h4>Conclusions</h4> Although there were technical limitations related to patient size that affected its ability to meet the strict accuracy criteria set by the American National Standards Institute/Association for the Advancement of Medical Instrumentation standards for noninvasive BP measurement (ANSI/AAMI SP10), the NICCI system provided a continuous noninvasive beat-to-beat BP measurement which was clinically relevant during a significant portion of intraoperative care.
Project description:<h4>Background</h4>Clinic-based blood pressure (BP) is a closely-tracked metric of health care quality, but is prone to inaccuracy and measurement imprecision. Recent guidelines have advocated for automated office blood pressure (AOBP) devices to improve clinic-based BP assessments.<h4>Methods</h4>Patients from a single hypertension clinic underwent a 3-day evaluation that included a 24-hour ambulatory blood pressure monitoring (ABPM), 2 manual clinic-based BP measurements (over 2 visits), and an unattended AOBP measurement (single visit). All measurements were compared to the average wake-time systolic BP (SBP) and diastolic BP (DBP) from ABPM.<h4>Results</h4>Among 103 patients (mean age 57.3 ± 14.8 years, 51% women, 29% black) the average wake-time SBP was 131.3 ± 12.3 mm Hg and DBP was 78.3 ± 9.2 mm Hg. The average of 2 manual BPs was significantly higher than wake-time ABPM with mean differences of 5.5 mm Hg (P < 0.001) for SBP and 2.7 mm Hg (P = 0.002) for DBP. In contrast, the averages of the last 2 AOBP measurements did not significantly differ from ABPM with mean differences of 1.6 mm Hg (P = 0.21) for SBP and -0.5 mm Hg (P = 0.62) for DBP. The estimated prevalence of SBP ? 140 or DBP ? 90 mm Hg based on wake-time ABPM was 27.2% vs. 49.5% based on the average of 2 manual measurements (difference 22.3%; P < 0.001) and 31.1% based on the average of the last 2 AOBP measurements (difference 3.9%; P = 0.57).<h4>Conclusions</h4>A single visit, unattended AOBP more precisely estimated BP and the prevalence of stage 2 and uncontrolled hypertension than even the average of 2 manual clinic visits, supporting guideline recommendations to use AOBP for clinic-based BP measurements.
Project description:BACKGROUND:Ambulatory blood pressure (BP) monitoring is the reference standard for out-of-clinic BP measurement. Thresholds for identifying ambulatory hypertension (daytime systolic BP [SBP]/diastolic BP [DBP] ?135/85 mm?Hg, 24-hour SBP/DBP ?130/80 mm?Hg, and nighttime SBP/DBP ?120/70 mm?Hg) have been derived from European, Asian, and South American populations. We determined BP thresholds for ambulatory hypertension in a US population-based sample of African American adults. METHODS:We analyzed data from the Jackson Heart Study, a population-based cohort study comprised exclusively of African American adults (n=5306). Analyses were restricted to 1016 participants who completed ambulatory BP monitoring at baseline in 2000 to 2004. Mean SBP and DBP levels were calculated for daytime (10:00 am-8:00 pm), 24-hour (all available readings), and nighttime (midnight-6:00 am) periods, separately. Daytime, 24-hour, and nighttime BP thresholds for ambulatory hypertension were identified using regression- and outcome-derived approaches. The composite of a cardiovascular disease or an all-cause mortality event was used in the outcome-derived approach. For this latter approach, BP thresholds were identified only for SBP because clinic DBP was not associated with the outcome. Analyses were stratified by antihypertensive medication use. RESULTS:Among participants not taking antihypertensive medication, the regression-derived thresholds for daytime, 24-hour, and nighttime SBP/DBP corresponding to clinic SBP/DBP of 140/90 mm?Hg were 134/85 mm?Hg, 130/81 mm?Hg, and 123/73 mm?Hg, respectively. The outcome-derived thresholds for daytime, 24-hour, and nighttime SBP corresponding to a clinic SBP ?140 mm?Hg were 138 mm?Hg, 134 mm?Hg, and 129 mm?Hg, respectively. Among participants taking antihypertensive medication, the regression-derived thresholds for daytime, 24-hour, and nighttime SBP/DBP corresponding to clinic SBP/DBP of 140/90 mm?Hg were 135/85 mm?Hg, 133/82 mm?Hg, and 128/76 mm?Hg, respectively. The corresponding outcome-derived thresholds for daytime, 24-hour, and nighttime SBP were 140 mm?Hg, 137 mm?Hg, and 133 mm?Hg, respectively, among those taking antihypertensive medication. CONCLUSIONS:On the basis of the outcome-derived approach for SBP and regression-derived approach for DBP, the following definitions for daytime, 24-hour, and nighttime hypertension corresponding to clinic SBP/DBP ?140/90 mm?Hg are proposed for African American adults: daytime SBP/DBP ?140/85 mm?Hg, 24-hour SBP/DBP ?135/80 mm?Hg, and nighttime SBP/DBP ?130/75 mm?Hg, respectively.
Project description:Background Studies of the association of hypertension with incident colorectal cancer (CRC) may have been confounded by including individuals taking antihypertensive medication, at high risk for CRC (ie, colorectal polyps and inflammatory bowel disease), or with shared risk factors (eg, obesity and diabetes). We assessed whether adults with untreated hypertension are at higher risk for incident CRC compared with those with normal blood pressure (BP), and whether any association is evident among individuals without obesity or metabolic abnormalities. Methods and Results Analyses were conducted using a nationwide health claims database collected in the JMDC Claims Database between 2005 and 2018 (n=2 220 112; mean age, 44.1±11.0 years; 58.4% men). Participants who were taking antihypertensive medications or had a history of CRC, colorectal polyps, or inflammatory bowel disease were excluded. Each participant was categorized as having normal BP (systolic BP [SBP]<120 mm Hg and diastolic BP [DBP] <80 mm Hg, n=1 164 807), elevated BP (SBP 120-129 mm Hg and DBP <80 mm Hg, n=341 273), stage 1 hypertension (SBP 130-139 mm Hg or DBP 80-89 mm Hg, n=466 298), or stage 2 hypertension (SBP ≥140 mm Hg or DBP ≥90 mm Hg, n=247 734). Over a mean follow-up of 1112±854 days, 6899 incident CRC diagnoses occurred. After multivariable adjustment, compared with normal BP, hazard ratios for incident CRC were 0.93 (95% CI, 0.85-1.01) for elevated BP, 1.07 (95% CI, 0.99-1.15) for stage 1 hypertension, and 1.17 (95% CI, 1.08-1.28) for stage 2 hypertension. The hazard ratios for incident CRC for each 10-mm Hg-higher SBP or DBP were 1.04 (95% CI, 1.02-1.06) and 1.06 (95% CI, 1.03-1.09), respectively. These associations were present among adults who did not have obesity, high waist circumference, diabetes, or dyslipidemia. Conclusions Higher SBP and DBP, and stage 2 hypertension are associated with a higher risk for incident CRC, even among those without shared risk factors for CRC. BP measurement could identify individuals at increased risk for subsequent CRC.
Project description:The authors assessed the process of blood pressure (BP) measurement and level of adherence to recommended procedures at representative sites throughout a large academic health sciences center. A casual observer assessed the setting and observed the process, noting the equipment, technique, and BP recorded by site personnel. A trained observer then repeated the patient's BP measurement following American Heart Association recommendations. Significant biases were observed between measurements by site personnel and the trained observer. Site personnel reported on average an increased systolic BP (SBP) of 5.66 mm Hg (95% confidence interval [CI], 3.09-8.23; P<.001) and a decreased diastolic BP (DBP) of -2.96 mm Hg (95% CI, -5.05 to -0.87; P=.005). Overall, 41% of patients had a ≥10-mm Hg difference in SBP between measurements. Similarly, 54% had differences of ≥5 mm Hg in DBP between measurements. Inaccurate BP measurement and poor technique may lead to misclassification, misdiagnosis, and inappropriate medical decisions. Concordance of measured SBP between our site personnel and trained observer was less than optimal. Several areas for improvement were identified. Routine calibration and use of system-wide standardized equipment, establishment of BP measurement protocols, and periodic technique and equipment recertification can be addressed in future quality initiatives.
Project description:<h4>Background</h4>An optimal blood pressure (BP) range to mitigate morbidity and mortality on left ventricular assist device (LVAD) support has not been clearly defined.<h4>Methods</h4>Average Doppler opening pressure, mean arterial pressure (MAP), and/or systolic blood pressure (SBP) were calculated in operative survivors (n = 16,155) of LVAD support in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS). BP distributions were used to group patients into low (BP <25th percentile), normal (25-75th percentile), high (75th-95th percentile), and very high (>95th percentile). Associations between BP and adverse events were evaluated using Cox regression (hazard ratio[HR], 95% confidence interval).<h4>Results</h4>The median (25th, 75th) MAP, Doppler, and SBP (mm Hg) during continuous flow LVAD support were 84 (77, 90), 85 (80, 92), and 99 (90, 107) mm Hg, respectively. BP had a bimodal risk association with survival. At 3 years, survival was 58% ± 1.8% in those with low MAP (≤75 mm Hg) vs 70% ± 0.9%, 71% ± 1.5%, and 63% ± 3.0% in the those with normal, high, or very high average MAP, respectively. Patients with chronically low MAP (≤75 mm Hg), Doppler (≤80 mm Hg), and SBP (<90 mm Hg) had 35%-42% higher adjusted hazards of death than patients with normal or high BP (p ≤ 0.0001). Patients with MAP >100 mm Hg, Doppler ≥105 mm Hg, and SBP ≥120 mm Hg had 17%-20% higher adjusted hazards of death than those with normal pressures (p < 0.05). In patients on axial flow LVADs, elevated SBP (HR 1.08 [95% confidence interval, 1.04-1.13] per 10 mm Hg increase) but not MAP correlated with increased incident of stroke.<h4>Conclusions</h4>In INTERMACS, BP extremes during LVAD support increase the risk for adverse events, supporting a MAP goal >75 mm Hg and <90 mm Hg. Hypotension conferred the highest risk for mortality. Excessive BP control should be avoided, and Doppler opening pressure should not be assumed to represent MAP in all patients.
Project description:<h4>Background</h4>Psychological stress contributes to blood pressure (BP) variability, which is a significant and independent risk factor for cardiovascular events. We compared the effectiveness of a recently developed wearable watch-type BP monitoring (WBPM) device and an ambulatory BP monitoring (ABPM) device for detecting ambulatory stress-induced BP elevation in 50 outpatients with 1 or more cardiovascular risk factors.<h4>Methods</h4>The WBPM and ABPM were both worn on the subject's nondominant arm. ABPM was measured automatically at 30-minute intervals, and each ABPM measurement was followed by a self-measured WBPM measurement. We also collected self-reported information about situational conditions, including the emotional state of subjects at the time of each BP measurement. We analyzed 642 paired BP readings for which the self-reported emotional state in the corresponding diary entry was happy, calm, anxious, or tense.<h4>Results</h4>In a mixed-effect analysis, there were significant differences between the BP values measured during negative (anxious, tense) and positive (happy, calm) emotions in both the WBPM (systolic BP [SBP]: 9.3 ± 2.1 mm Hg, P < 0.001; diastolic BP [DBP]: 8.4 ± 1.4 mm Hg, P < 0.001) and ABPM (SBP: 10.7 ± 2.1 mm Hg, P < 0.001; DBP: 5.6 ± 1.4 mm Hg, P < 0.001). The absolute BP levels induced by emotional stress self-measured by the WBPM were similar to those automeasured by the ABPM (SBP, WBPM: 141.1 ± 2.7 mm Hg; ABPM: 140.3 ± 2.7 mm Hg; P = 0.724). The subject's location at the BP measurement was also significantly associated with BP elevation.<h4>Conclusions</h4>The self-measurement by the WBPM could detect BP variability induced by multiple factors, including emotional stress, under ambulatory conditions as accurately as ABPM.
Project description:<h4>Objectives</h4>This study quantified the change in blood pressure (BP) during antivascular endothelial growth factor (VEGF) tyrosine kinase inhibitor (TKI) therapy, compared BPs between TKIs, and analyzed change in BP during antihypertensive therapy.<h4>Background</h4>TKIs targeting VEGF are associated with hypertension. The absolute change in BP during anti-VEGF TKI treatment is not well characterized outside clinical trials.<h4>Methods</h4>A retrospective single-center study included patients with metastatic renal cell carcinoma who received anti-VEGF TKIs between 2007 and 2018. Mixed models analyzed 3,088 BPs measured at oncology clinics.<h4>Results</h4>In 228 patients (baseline systolic blood pressure [SBP] 130.2 ± 16.3 mm Hg, diastolic blood pressure [DBP] 76.8 ± 9.3 mm Hg), anti-VEGF TKIs were associated with mean increases in SBP of 8.5 mm Hg (p < 0.0001) and DBP of 6.7 mm Hg (p <0.0001). Of the anti-VEGF TKIs evaluated, axitinib was associated with the greatest BP increase, with an increase in SBP of 12.6 mm Hg (p < 0.0001) and in DBP of 10.3 mm Hg (p < 0.0001) relative to baseline. In pairwise comparisons between agents, axitinib was associated with greater SBPs than cabozantinib by 8.4 mm Hg (p = 0.004) and pazopanib by 5.1 mm Hg (p = 0.01). Subsequent anti-VEGF TKI courses were associated with small increases in DBP, but not SBP, relative to the first course. During anti-VEGF TKI therapy, calcium-channel blockers and potassium-sparing diuretic agents were associated with the largest BP reductions, with decreases in SBP of 5.6 mm Hg (p < 0.0001) and 9.9 mm Hg (p = 0.007), respectively.<h4>Conclusions</h4>Anti-VEGF TKIs are associated with increased BP; greatest increases are observed with axitinib. Calcium-channel blockers and potassium-sparing diuretic agents were associated with the largest reductions in BP.
Project description:To investigate the optimal blood pressure (BP) levels and relative importance of BP and BP variability in the early phase of acute ischemic stroke (AIS) for hypertensive patients with carotid artery stenosis (CAS). A single-center cohort study included 750 AIS patients with hypertension and tests were performed for CAS. Participants were categorized to Group 1 (SBP < 140 mm Hg and DBP < 90 mm Hg), Group 2: (SBP: 140-159 mm Hg and or DBP: 90-99 mm Hg), and Group 3: (SBP ≥160 mm Hg and/or DBP ≥100 mm Hg) according to the guidelines. The associations of mean BP levels and variability with outcomes (recurrent stroke, all-cause death and the composite cardiovascular events) at 6 months were analyzed by Cox proportional hazard models. The associations of BP variability with BP levels and cerebral blood flow (CBF) were analyzed by linear regression and generalized additive models. Both for primary and secondary outcome, more events occurred in Group 1 compared with Group 2, while no significant difference was found in Group 3 with higher BP levels. Lower systolic BP variability showed better prognosis and higher CBF. The associations were more significant in patients with CAS ≥50%. BP variability exhibited a linear negative relationship with BP levels. In the early phase of AIS with hypertension and CAS, maintaining low blood pressure variability may be important to improve outcomes while low BP levels (SBP/DBP < 140/90 mm Hg) were harmful, especially in those patients with CAS ≥ 50%.
Project description:Background: We examined the cross-sectional and longitudinal associations of objectively-measured physical activity (step counts) and blood pressure (BP) among adults spanning 37 countries. Methods: Across 37 countries, we used data from a pool of 9238 adult owners of Withings' Pulse activity trackers, which measures steps taken each day, and Wireless Blood Pressure Monitor, which measures BP. Analyses were adjusted on age, sex, number of days where the tracker was worn, and number of BP measurements. Data was collected from 2009 to 2013. Results: Subjects had a mean ± standard deviation (SD) age of 51.6 ± 11.3 years and a body mass index (BMI) of 28.7±5.5 kg/m2. A 1-month increase of more than 3000 steps per day was associated with a decrease of systolic BP (SBP) and diastolic BP (DBP) among the obese (1.57mm Hg and 1.29 mm Hg respectively, both P<0.001) and the overweight population (0.79 mm Hg and 0.84 mm Hg respectively, both P?0.001), but not in the normal weight population (P=0.60 and P=0.36 respectively). Conclusion: One-month increases in daily step counts was associated with a decrease of SBP and DBP in a large obese and overweight free living population.