Research and Development of Information and Communication Technology-based Home Blood Pressure Monitoring from Morning to Nocturnal Hypertension

Asians have specific characteristics of hypertension (HTN) and its relationship with cardiovascular disease. The morning surge in blood pressure (BP) in Asians is more extended, and the association slope between higher BP and the risk for cardiovascular events is steeper in this population than in whites. Thus, 24-hour BP control including at night and in the morning is especially important for Asian patients with HTN. There are 3 components of “perfect 24-hour BP control”: the 24-hour BP level, adequate dipping of nocturnal BP (dipper type), and adequate BP variability such as the morning BP surge. The morning BP-guided approach using home BP monitoring (HBPM) is the first step toward perfect 24-hour BP control. After controlling morning HTN, nocturnal HTN is the second target. We have been developing HBPM that can measure nocturnal BP. First, we developed a semiautomatic HBPM device with the function of automatic fixed-interval BP measurement during sleep. In the J-HOP (Japan Morning Surge Home Blood Pressure) study, the largest nationwide home BP cohort, we successfully measured nocturnal home BP using this device with data memory, 3 times during sleep (2, 3, and 4 am), and found that nocturnal home BP is significantly correlated with organ damage independently of office and morning BP values. The second advance was the development of trigger nocturnal BP (TNP) monitoring with an added trigger function that initiates BP measurements when oxygen desaturation falls below a variable threshold continuously monitored by pulse oximetry. TNP can detect the specific nocturnal BP surges triggered by hypoxic episodes in patients with sleep apnea syndrome. We also added the lowest heart rate-trigger function to TNP to detect the “basal nocturnal BP,” which is determined by the circulating volume and structural cardiovascular system without any increase in sympathetic tonus. This double TNP is a novel concept for evaluating the pathogenic pressor mechanism of nocturnal BP. These data are now collected using an information and communication technology (ICT)-based monitoring system. The BP variability includes different time-phase variability from the shortest beat-by-beat, positional, diurnal, day-by-day, visit-to-visit, seasonal, and the longest yearly changes. The synergistic resonance of each type of BP variability would produce great dynamic BP surges, which trigger cardiovascular events. Thus, in the future, the management of HTN based on the simultaneous assessment of the resonance of all of the BP variability phenotypes using a wearable “surge” BP monitoring device with an ICT-based data analysis system will contribute to the ultimate individualized medication for cardiovascular disease

Comparison of nighttime measurement schedules using a wrist‐type nocturnal home blood pressure monitoring device

Abstract We investigated the optimal nighttime home blood pressure (BP) measurement schedule for wrist BP monitoring. Fifty hypertensive patients (mean age 68.9 ± 11.3 years) self‐measured their nighttime BP hourly using a wrist‐type nocturnal home BP monitoring device at home on two consecutive nights. Using the average 7.2 ± 1.5 measurements per night, we compared the clock‐based index (average of three measurements at 2:00, 3:00, and 4:00 a.m.) and the bedtime‐based index (average of three measurements at 2, 3, and 4 h after bedtime). The clock‐based average was significantly higher than the bedtime‐based average for both systolic BP (2.7 ± 8.2 mmHg, P = .002) and diastolic BP (1.9 ± 5.1 mmHg, P < .001). Compared to the average of all measurements throughout a night (the same definition of ambulatory BP monitoring, ie, from the time point of going to bed to awakening), the clock‐based average was comparable (systolic/diastolic BP: −0.5 ± 5.5/−0.2 ± 3.7), whereas the bedtime‐based average was significantly lower (−3.3 ± 5.0/−2.1 ± 3.6). Thus, the repeated measurement of wrist‐measured nighttime BP at three clock‐based time points per night provided reliable values. Further prospective studies of larger populations are required to confirm the optimal nighttime BP measurement schedule for wrist BP monitoring for the prediction of cardiovascular events

Self‐measured worksite blood pressure and its association with organ damage in working adults: Japan Morning Surge Home Blood Pressure (J‐HOP) worksite study

Abstract The effects of elevations in blood pressure (BP) on worksite stress as an out‐of‐office BP setting have been evaluated using ambulatory BP monitoring but not by self‐measurement. Herein, we determined the profile of self‐measured worksite BP in working adults and its association with organ damage in comparison with office BP and home BP measured by the same home BP monitoring device. A total of 103 prefectural government employees (age 45.3 ± 9.0 years, 77.7% male) self‐measured their worksite BP at four timepoints (before starting work, before and after a lunch break, and before leaving the workplace) and home BP in the morning, evening, and nighttime (at 2, 3, and 4 a.m.) each day for 14 consecutive days. In the total group, the average worksite systolic BP (SBP) was significantly higher than the morning home SBP (129.1 ± 14.3 vs. 124.4 ± 16.4 mmHg, p = .026). No significant difference was observed among the four worksite SBP values. Although the average worksite BP was higher than the morning home BP in the study participants with office BP < 140/90 mmHg (SBP: 121.4 ± 9.4 vs. 115.1 ± 10.4 mmHg, p < .001, DBP: 76.0 ± 7.7 vs. 72.4 ± 8.4 mmHg, p = .013), this association was not observed in those with office BP ≥ 140/90 mmHg or those using antihypertensive medication. Worksite SBP was significantly correlated with the left ventricular mass index evaluated by echocardiography (r = 0.516, p < .0001). The self‐measurement of worksite BP would be useful to unveil the risk of hypertension in working adults who show normal office and home BP

Reproducibility of nighttime home blood pressure measured by a wrist‐type nocturnal home blood pressure monitoring device

Abstract The authors investigated the reproducibility of nighttime home blood pressure (BP) measured by a wrist‐type BP monitoring device. Forty‐six hypertensive patients (mean 69.0±11.6 years, 56.5% male) self‐measured their nighttime BP hourly using simultaneously worn wrist‐type and upper arm‐type nocturnal home BP monitoring devices at home on two consecutive nights. Using the average 7.4±1.3 measurements on the first night and the average 7.0 ± 1.8 measurements on the second night, the authors assessed the reliability and the reproducibility of nighttime BP measured on the two nights. The difference between nights in systolic BP (SBP) measured by the wrist‐device was not significant (1.6±7.0 mmHg, p = .124), while the difference in diastolic BP (DBP) was marginally significant (1.4±4.9 mmHg, p = .050). The intraclass correlation coefficients (ICCs) for agreement between nights were high both in SBP and DBP average (SBP: 0.835, DBP: 0.804). Averaging only three points of SBP resulted in lower ICC values, but still indicated good correlations (ICC > 0.6). On the other hand, the correlations of the standard deviation and average real variability of SBP between nights were low, with ICCs of 0.220 and 0.436, respectively. In conclusion, the average SBP values measured on the first night were reliable even when averaging only three readings. The reproducibility of nighttime BP variability seemed inferior to that of BP average; it might be better to measure nighttime BP over multiple nights to assess BP variability. However, this hypothesis needs verification in other study population. In addition, our study population had well‐controlled BP, which limits the generalizability of this findings to all hypertensive patients

Comparison of ambulatory blood pressure-lowering effects of higher doses of different calcium antagonists in uncontrolled hypertension: the Calcium Antagonist Controlled-Release High-Dose Therapy in Uncontrolled Refractory Hypertensive Patients (CARILLON) Study

Background: Data are sparse regarding ambulatory blood pressure (BP) reduction of up-titration from a standard dose to a high dose in both nifedipine controlled-release (CR) and amlodipine. This was a prospective, randomized, multicenter, open-label trial. Patients and methods: Fifty-one uncontrolled hypertensives medicated by two or more antihypertensive drugs including a renin-angiotensin system inhibitor and a calcium antagonist were randomly assigned to either the nifedipine CR (80 mg)/candesartan (8 mg) group or the amlodipine (10 mg)/candesartan (8 mg) group. Results: The changes in 24-hr BP were comparable between the groups. The nifedipine group demonstrated a significant decrease in their urinary albumin creatinine ratio, whereas the amlodipine group demonstrated a significant decrease in their NTproBNP level. However, there was no significant difference in any biomarkers between the two groups. Conclusion: Nifedipine showed an almost equal effect on ambulatory blood pressure as amlodipine. Their potentially differential effects on renal protection and NTproBNP should be tested in larger samples

Comparative effects of valsartan plus cilnidipine or hydrochlorothiazide on nocturnal home blood pressure

Abstract We tested our hypothesis that, in hypertensive patients with higher nocturnal home systolic blood pressure (HSBP) at baseline, a valsartan/cilnidipine (80/10 mg) combination would reduce nocturnal HSBP more markedly than a valsartan/hydrochlorothiazide (80/12.5 mg) combination. Patients measured their nocturnal HSBP over three nights prior to study randomization and at the end of treatment. Sixty‐three and 66 patients comprised the valsartan/cilnidipine and valsartan/hydrochlorothiazide groups; their respective baseline nocturnal HSBP values were 124.3 ± 15.6 and 125.8 ± 15.2 mm Hg (P = .597). Nocturnal HSBPs were significantly reduced from baseline in both groups. Although the valsartan/hydrochlorothiazide group exhibited a significantly greater reduction in nocturnal HSBP compared to the valsartan/cilnidipine group (−5.0 vs. −10.0 mm Hg, P = .035), interaction between the treatment groups and the baseline nocturnal HSBP levels for the changes in nocturnal HSBP after the treatment periods was significant (P = .047). The BP‐lowering effect of valsartan/cilnidipine was more dependent on baseline nocturnal HSBP than that of valsartan/hydrochlorothiazide

Simultaneous self‐monitoring comparison of a supine algorithm‐equipped wrist nocturnal home blood pressure monitoring device with an upper arm device

Abstract A nocturnal home blood pressure (BP) monitoring device that measures nighttime BP levels accurately with less sleep disturbance is needed for the 24‐h management of hypertension. Here we conducted the first comparison study of simultaneous self‐monitoring by both a supine position algorithm‐equipped wrist nocturnal home BP monitoring device, the HEM‐9601T (NightView; Omron Healthcare) with a similar upper arm device, the HEM‐9700T (Omron Healthcare) in 50 hypertensive patients (mean age 68.9 ± 11.3 years). Both devices were worn on the same non‐dominant arm during sleep over two nights. The patients self‐measured their nighttime BP by starting nocturnal measurement mode just before going to bed. In total, 694 paired measurements were obtained during two nights (7.2 ± 1.5 measurements per night), and the mean differences (±SD) in systolic BP between the devices was 0.2 ± 10.2 mmHg (p = .563), with good agreement. In the comparison of nighttime BP indices, the difference in average SBP at 2:00, 3:00, and 4:00 AM and the average SBP of 1‐h interval measurements was −0.5 ± 5.5 mmHg (p = .337), with good agreement. The HEM‐9601T substantially reduced sleep disturbance compared to the upper arm‐type device. The newly developed HEM‐9601T (NightView) can thus accurately measure BP during sleep without reducing the wearer's sleep quality

Assessment of a new algorithm to detect atrial fibrillation in home blood pressure monitoring device among healthy adults and patients with atrial fibrillation

The authors evaluated the diagnostic accuracy of a new algorithm for detecting atrial fibrillation (AF) using a home blood pressure (BP) monitor. Three serial BP values were measured in 205 subjects with sinus rhythm and 75 subjects with AF confirmed by electrocardiogram. Irregular pulse peak (IPP) 15 was defined as follows: |interval of pulse peak ‐ the average of the interval of the pulse peak| ≥ the average of the interval of the pulse peak × 15%. Irregular heartbeat (IHB) was defined as follows: beats of IPP ≥ total pulse × 20%. The sensitivities of IPP15 for diagnosing AF defined as two or three IHBs of three readings were 1.0 and 0.99, and the corresponding specificities were 0.97 and 0.99, respectively. The algorithm using two or more IHBs of three readings in the setting of IPP15 had the highest diagnostic accuracy for AF