Ambulatory Blood Pressure Characteristics of Patients with Alzheimer’s Disease: A Multicenter Study from China

Background: Previous studies revealed that abnormal blood pressure (BP) plays an important role in the pathogenesis of Alzheimer’s disease (AD). However, little is known about the ambulatory BP characteristics of AD in the mild or severe stage. Objective: We explored the ambulatory BP characteristics of AD in the mild or severe stage. Methods: In the present study, 106 AD patients (42.5%male, average age 81.6 years) were enrolled from three centers in China. Clinal BP measurements at the supine and standing positions, neurological evaluations, and the 24 h ambulatory BP monitoring were performed. Results: In the 106 AD patients, 49.2%, 36.8%, and 70%of patients had 24 h, daytime, and nighttime systolic hypertension, respectively, while 19.8%, 29.2%, and 5.7%had 24 h, daytime, and nighttime diastolic hypotension. The prevalence of the reduced and reverse dipping pattern was 34.0%and 48.1%for systolic BP and 32.1%and 45.3%for diastolic BP, respectively. The daytime diastolic BP was significantly correlated with cognitive performance. After adjustment for age, sex, and body mass index, only daytime diastolic BP was associated with remarkable cognitive deterioration (p≤0.008). Further, AD patients in the severe stage had significantly lower levels of the 24 h, daytime, and nighttime diastolic BP, compared with those in the mild stage. Conclusion: In general, AD patients were featured with high nighttime systolic BP, low daytime diastolic BP, and abnormal circadian BP rhythm of reduced and reverse dipping. The diastolic BP, especially daytime diastolic BP, was adversely correlated with the cognitive deterioration in AD.

Clinical cases of difficulty in interpreting the results of 24 hour blood pressure monitoring in men of military age

The article describes 2 clinical cases with signs of deliberate manipulation by patients of the results of ambulatory BP monitoring, leading to an increase of mean blood pressure. Such findings, as experience shows, are often revealed in men of military age. The value of additional recording channels, such as ECG, physical activity and body position, rheopneumogram, for an objective assessment of such findings is shown. The main factors that can lead to an increase in blood pressure during ABPM are listed. Conclusion examples for describing such changes are given.

Abstract P096: Association Of Accurately Measured Office, Self-measured Home, And Ambulatory Blood Pressure And Their Variability With Intracranial Arterial Stenosis

Background: Few studies have compared accurately measured office, self-measured home, and ambulatory blood pressure (BP) for asymptomatic intracranial artery stenosis (ICAS). Relationship of day-by-day or short-term variability in BP to asymptomatic ICAS remains unclear. Objectives: To examine the association of office, home (mean value and day-by-day variability), and ambulatory BP indices (24-hour/daytime/nighttime mean values, short-term variability, nocturnal decline, and morning pressor surge) with asymptomatic ICAS. Methods: Data on office and 7-day home BP and magnetic resonance angiography to assess ICAS were obtained in 677 men (mean age, 70.0 years) from a population-based cohort. Among them, 468 underwent 24-hour ambulatory BP monitoring. Mild- or severe-ICAS was defined as 1-49% or ≥50% stenosis, respectively, and any-ICAS as either mild or severe-ICAS. Results: We observed mild- and severe-ICAS in 153 (22.6%) and 36 (5.3%) participants, respectively. In multivariable Poisson regression with robust error variance, higher systolic BP at office, home, or ambulatory BP monitoring was associated with the presence of any- or severe-ICAS. The associations with ICAS were comparable between office, home, and ambulatory systolic BP (all heterogeneity Ps >0.1). Independent of mean systolic BP, greater nocturnal decline or morning pressor surge in systolic BP was associated with higher burden of any- or severe-ICAS. Conclusion: The magnitude of association of BP accurately measured at office for asymptomatic ICAS was comparable with that of BP at home or ambulatory BP monitoring. Circadian BP variation based on ambulatory BP monitoring may be considered when assessing ICAS in apparently healthy individuals.

Non-dipping pattern of nocturnal blood pressure as a risk factor for macular ischemia in branch retinal vein occlusion

Branch retinal vein occlusion (BRVO) is ocular vascular disease affecting approximately 14 million people worldwide, and is closely associated with high blood pressure (BP). Although macular ischemia is a critical factor in the visual prognosis of BRVO, the relationship between macular ischemia and different patterns of nocturnal BP is unknown. Here, we investigated whether a dipping pattern of nocturnal BP is associated with the development of macular ischemia in patients with BRVO. A total of 273 patients were reviewed; of these, 86 (86 eyes) patients were included. All recruited patients had a macular thickness map by optical coherence tomography and underwent 24-h ambulatory BP monitoring. According to their dipping patterns, the participants were divided into dipper and non-dipper groups. The non-dipper group had worse visual outcomes at the initial and 6-month visits (P = 0.014 and P = 0.003, respectively). Five of 32 eyes (15.6%) in the dipper group and 32 of 54 (59.3%) in the non-dipper group had macular ischemia. In a multivariate analysis, the night-to-day systolic BP ratio was associated with the degree of macular ischemia (β = − 0.313, P = 0.004). Thus, a non-dipping pattern may be a risk factor for macular ischemia in patients with BRVO.

MO717EFFECT ON BLOOD PRESSURE OF UNCOMPENSATED 130 MM SODIUM DIALYSATE IN CAPD PATIENT WITH RESISTANT HYPERTENSION

Background and Aims In peritoneal dialysis (PD) blood pressure (BP) control is largely unsatisfied mainly due to sodium retention. Currently, sodium removal in PD patients depends substantially on ultrafiltration. Lowering sodium in PD solution might improve sodium removal by diffusion, though the real benefit of low PD solution remains still undetermined. Method In this case report, we used a novel uncompensated glucose-based PD solution (DextroCore LS, Iperboreal Pharma, Italy) containing 130 mM sodium to treat resistant hypertension in 78-year-old female treated by CAPD (3 dwells glucose 1.5% a day, Na 132). Results At baseline, Ambulatory BP monitoring (ABPM) showed 24h-BP (152/81 mmHg), diurnal BP (151/83 mmHg) and nocturnal BP (153/75 mmHg), with inversion of circadian rhythm in systolic BP (systolic night/day ratio: 1.02), despite the use of three anti-hypertensive (doxazosin 4mg, amlodipine 10 mg, telmisartan 80 mg) and diuretic (furosemide 250 mg) at adequate doses. She had no signs of hypervolemia. We switched from standard PD (132 mM/L) to low sodium PD solution using 1.5% glucose bags with sodium concentration of 130 mM. CAPD schedule was confirmed. Second ABPM after six months reported a reduction 24h BP (131/73 mmHg), diurnal (134/75 mmHg) and nocturnal BP (122/67 mmHg), with restoring of circadian BP rhythm. No change in body weight, UF and residual diuresis was found. Diet and therapy prescriptions were unmodified. No side effects were reported. Conclusion Six-months PD treatment with uncompensated glucose-based PD solution containing 130 mM sodium in all daily dwells has allowed to reduce systolic BP (-16 mmHg) in a CAPD patient affected by resistant hypertension, with no change in ultrafiltration and residual diuresis.

MO108ACCURACY OF PERIDIALYTIC, INTRADIALYTIC AND SCHEDULED INTERDIALYTIC RECORDINGS FOR DIAGNOSING HIGH AMBULATORY BLOOD PRESSURE IN HEMODIALYSIS

Background and Aims Hypertension is highly prevalent in hemodialysis patients. Current recommendations suggest the use of ambulatory-BP-monitoring (ABPM) as the gold-standard for hypertension diagnosis and management in these subjects. This study assessed the accuracy of peridialytic, intradialytic and scheduled interdialytic recordings in diagnosing high 44-h interdialytic BP. Method A total of 242 hemodialysis patients that underwent valid 48-h ABPM were included in the analysis. We used ambulatory BP as reference standard and tested the accuracy of the following BP metrics: Pre- and post-dialysis, Intradialytic, Intradialytic plus pre/post-dialysis readings and Scheduled interdialytic BP (out-of-dialysis day: readings at 8:00 am, 8:00 pm or their average). Results 44-h SBP/DBP levels had significant differences with and pre- or post-dialysis BP, but no or minor differences with any of the other BP metrics. 44-h SBP and DBP correlated strongly with Intradialytic (r=0.713/0.753, p<0.001), Intradialytic plus pre/post-dialysis (r=0.725/0.758, p<0.001) and averaged Scheduled interdialytic BP (r=0.874/0.823, p<0.001). Bland-Altman plots showed absence of systemic bias for all index metrics, but large between-method difference and wider 95% limits of agreement for pre- and post-dialysis BP compared to Intradialytic, Intradialytic plus pre/post-dialysis and averaged Scheduled interdialytic BP. In ROC-analysis for diagnosing 44-h SBP≥130mmHg, the Area-Under-the-Curve of pre-dialysis (0.723) and post-dialysis SBP (0.746) were significantly lower than that of Intradialytic (0.850), Intradialytic plus pre/post-dialysis (0.850) and Scheduled interdialytic SBP (0.917) (z-test, p<0.001 for all pairwise comparisons). The corresponding sensitivity/specificity values were 76.6%/54.5%, 78.7%/59.4%, 73.0%/81.2%, 68.1%/88.1% and 82.3%/89.1%, respectively. Similar observations were made for DBP. Conclusion In contrast to pre- and post-dialysis BP, the average of intradialytic, intradialytic plus pre/post-dialysis or scheduled interdialytic BP recordings show reasonable agreement with ambulatory BP and may be used for hypertension diagnosis and management in hemodialysis.

Association Between Ambulatory Blood Pressure and Coronary Artery Calcification

High blood pressure (BP) based on measurements obtained in the office setting has been associated with the presence and level of coronary artery calcification (CAC)—a measure of subclinical atherosclerosis. We studied the association between out-of-office BP and CAC among 557 participants who underwent 24-hour ambulatory BP monitoring at visit 1 in 2000–2004 and a computed tomography scan at visit 2 in 2005–2008 as part of the JHS (Jackson Heart Study)—a community-based cohort of African American adults. Mean awake, asleep, and 24-hour BP were calculated for each participant. Among participants included in this analysis, 279 (50%) had any CAC defined by an Agatston score >0. After multivariable adjustment including office systolic BP (SBP), the prevalence ratios for any CAC comparing the highest versus the lowest quartiles of SBP on ambulatory BP monitoring were 1.08 (95% CI, 0.84–1.39) for awake SBP, 1.32 (95% CI, 1.01–1.74) for asleep SBP, and 1.19 (95% CI, 0.91–1.55) for 24-hour SBP. After multivariable adjustment including office diastolic BP, the prevalence ratios for any CAC comparing the highest versus the lowest quartiles of awake, asleep, and 24-hour diastolic BP were 1.27 (95% CI, 1.02–1.59), 1.29 (95% CI, 1.02–1.64), and 1.25 (95% CI, 0.99–1.59), respectively. The current results suggest that higher asleep SBP and higher awake and asleep diastolic BP may be risk factors for subclinical atherosclerosis and underscore the potential role of ambulatory BP monitoring in identifying individuals at high risk for coronary artery disease.

Abstract P637: Blood Pressure Stability Has a Closer Relationship With Atherosclerosis Burden of Carotid Sinuses Than Atherosclerosis Burden of Aortic Arch

Background: Instable blood pressure (BP) increased vascular risk independently of high BP level, which might be partially attributed to impaired arterial baroreflex. The receptors of baroreflex mainly distributed at carotid sinuses and aortic arch, where atherosclerosis (AS) is common in patients with ischemic stroke (IS) and potentially blunts the baroreflex. We aimed to test whether AS conditions of carotid sinuses and aortic arch would equally indicate BP instability in IS patients. Methods: The daytime and nighttime standard derivations (SDs) of systolic BP (SBP) and diastolic BP (DBP) were recorded by ambulatory BP monitoring on the sixth day after IS to measure BP stability (higher SD indicates less stability). Using computed tomography angiography, AS conditions of carotid sinuses (6 segments) and aortic arch (4 segments) were scored based on AS percentage of each segment circumference (0, none; 1, <25%; 2, 25%~49%; 3, 50%~74%; 4, ≥75%) and summed into “carotid sinuses AS burden (CSAB)” and “aortic arch AS burden (AAAB)”. AS conditions of cervicocephalic arteries were also scored. Results: Of the 245 patients with IS, 65.7% had carotid sinuses AS and 69.4% had aortic arch AS. Daytime SBP SD was positively correlated with CSAB ( r =0.230; P <0.001) rather than AAAB ( P =0.103). Patients with CSAB above the median had significantly higher daytime SBP SD than those with less CSAB (median 14 mmHg vs. 12 mmHg, P =0.001). CSAB remained related to ln- transformed daytime SBP SD after adjusting for age, sex, vascular risk factors, weighted 24-hour means of SBP and DBP, and cervicocephalic AS score (adjusted B =0.012; 95% CI, 0.004-0.020). In contrast, DBP SD and nighttime SBP SD had no statistically significant association with both CSAB and AAAB. Conclusions: Higher CSAB was independently associated with SBP instability during the daytime, while AAAB was less relevant to BP stability. Compared with AAAB, evaluating CSAB might be more important in the prediction of BP instability.

Ambulatory Blood Pressure Monitoring to Diagnose and Manage Hypertension

This review portrays how ambulatory blood pressure (BP) monitoring was established and recommended as the method of choice for the assessment of BP and for the rational use of antihypertensive drugs. To establish much-needed diagnostic ambulatory BP thresholds, initial statistical approaches evolved into longitudinal studies of patients and populations, which demonstrated that cardiovascular complications are more closely associated with 24-hour and nighttime BP than with office BP. Studies cross-classifying individuals based on ambulatory and office BP thresholds identified white-coat hypertension, an elevated office BP in the presence of ambulatory normotension as a low-risk condition, whereas its counterpart, masked hypertension, carries a hazard almost as high as ambulatory combined with office hypertension. What clinically matters most is the level of the 24-hour and the nighttime BP, while other BP indexes derived from 24-hour ambulatory BP recordings, on top of the 24-hour and nighttime BP level, add little to risk stratification or hypertension management. Ambulatory BP monitoring is cost-effective. Ambulatory and home BP monitoring are complimentary approaches. Their interchangeability provides great versatility in the clinical implementation of out-of-office BP measurement. We are still waiting for evidence from randomized clinical trials to prove that out-of-office BP monitoring is superior to office BP in adjusting antihypertensive drug treatment and in the prevention of cardiovascular complications. A starting research line, the development of a standardized validation protocol for wearable BP monitoring devices, might facilitate the clinical applicability of ambulatory BP monitoring.