Eeva P. Juhanoja

Outcome-Driven Thresholds for Increased Home Blood Pressure Variability

Increased blood pressure (BP) variability predicts cardiovascular disease, but lack of operational thresholds limits its use in clinical practice. Our aim was to define outcome-driven thresholds for increased day-to-day home BP variability. We studied a population-based sample of 6238 individuals (mean age 60.0±12.9, 56.4% women) from Japan, Greece, and Finland. All participants self-measured their home BP on ≥3 days. We defined home BP variability as the coefficient of variation of the first morning BPs on 3 to 7 days. We assessed the association between systolic/diastolic BP variability (as a continuous variable and in deciles of coefficient of variation) and cardiovascular outcomes using Cox regression models adjusted for cohort and classical cardiovascular risk factors, including BP. During a follow-up of 9.3±3.6 years, 304 cardiovascular deaths and 715 cardiovascular events occurred. A 1 SD increase in systolic/diastolic home BP variability was associated with increased risk of cardiovascular mortality (hazard ratio, 1.17/1.22; 95% confidence interval, 1.06–1.30/1.11–1.34; P=0.003/<0.0001) and cardiovascular events (hazard ratio, 1.13/1.14; 95% confidence interval, 1.05–1.21/1.07–1.23; P=0.0007/0.0002). Compared with the average risk in the whole population, risk of cardiovascular deaths (hazard ratio, 1.66/1.84; 95% confidence interval, 1.27–2.17/1.42–2.37; P=0.0002/<0.0001) and events (hazard ratio, 1.46/1.42; 95% confidence interval, 1.21–1.76/1.17–1.71; P<0.0001/0.0004) was increased in the highest decile of systolic/diastolic BP variability (coefficient of variation>11.0/12.8). Increased home BP variability predicts cardiovascular outcomes in the general population. Individuals with a systolic/diastolic coefficient of variation of day-to-day home BP >11.0/12.8 may have an increased risk of cardiovascular disease. These findings could help physicians identify individuals who are at an increased cardiovascular disease risk.

Agreement between ambulatory, home, and office blood pressure variability

Objective: Ambulatory, home, and office blood pressure (BP) variability are often treated as a single entity. Our aim was to assess the agreement between these three methods for measuring BP variability. Methods: Twenty-four-hour ambulatory BP monitoring, 28 home BP measurements, and eight office BP measurements were performed on 461 population-based or hypertensive participants. Five variability indices were calculated for all measurement methods: SD, coefficient of variation, maximum–minimum difference, variability independent of the mean, and average real variability. Pearsons correlation coefficients were calculated for indices measured with different methods. The agreement between different measurement methods on the diagnoses of extreme BP variability (participants in the highest decile of variability) was assessed with kappa (&kgr;) coefficients. Results: SBP/DBP variability was greater in daytime (coefficient of variation: 9.8 ± 2.9/11.9 ± 3.6) and night-time ambulatory measurements (coefficient of variation: 8.6 ± 3.4/12.1 ± 4.5) than in home (coefficient of variation: 4.4 ± 1.8/4.7 ± 1.9) and office (coefficient of variation: 4.6 ± 2.4/5.2 ± 2.6) measurements (P < 0.001/0.001 for all). Pearsons correlation coefficients for systolic/diastolic daytime or night-time ambulatory–home, ambulatory–office, and home–office variability indices ranged between 0.07–0.25/0.12–0.23, 0.13–0.26/0.03–0.22 and 0.13–0.24/0.10–0.19, respectively, indicating, at most, a weak positive (r < 0.3) relationship. The agreement between measurement methods on diagnoses of extreme SBP/DBP variability was only slight (&kgr; < 0.2), with the &kgr; coefficients for daytime and night-time ambulatory–home, ambulatory-office, and home-office agreement varying between-0.014–0.20/0.061–0.15, 0.037–0.18/0.082–0.15, and 0.082–0.13/0.045–0.15, respectively. Conclusion: Shorter-term and longer-term BP variability assessed by different methods of BP measurement seem to correlate only weakly with each other. Our study suggests that BP variability measured by different methods and timeframes may reflect different phenomena, not a single entity.

The association between home vs. ambulatory night-time blood pressure and end-organ damage in the general population

Objective: The aim of this study was to test the agreement between night-time home and night-time ambulatory blood pressure (BP) and to compare their associations with hypertensive end-organ damage for the first time in the general population. Methods: A population sample of 248 participants underwent measurements for night-time home BP (three measurements on two nights with a timer-equipped home device), night-time ambulatory BP, pulse wave velocity (PWV), carotid intima–media thickness (IMT) and echocardiographic left ventricular mass index (LVMI). Results: No significant or systematic differences were observed between mean night-time ambulatory and home BPs (systolic/diastolic difference: 0.7 ± 7.6/0.2 ± 6.0 mmHg, P = 0.16/0.64). All night-time home and ambulatory BPs were positively correlated with PWV, IMT and LVMI (P < 0.01 for all). No significant differences in Pearsons correlations between end-organ damage and night-time home or ambulatory BP were observed (P ≥ 0.11 for all comparisons using Dunn and Clarks Z), except for a slightly stronger correlation between PWV and ambulatory SBP than for home SBP (r = 0.57 vs. 0.50, P = 0.03). The adjusted R2 of all multivariable-adjusted models for PWV, IMT or LVMI that included night-time home or ambulatory SBP/DBP were within 2/1%. Conclusion: Our study demonstrates that night-time home and ambulatory measurements produce similar BP values that have comparable associations with end-organ damage in the general population even when a clinically feasible measurement protocol is used for measuring night-time home BP. In the future, night-time home BP measurement may offer a feasible and easily accessible alternative to ambulatory monitoring for the measurement of night-time BP.

The impact of the day of the week on home blood pressure: the Finn-Home study.

ObjectiveThe impact of the day of the week on home blood pressure (BP) level and day-to-day BP profile is unknown. Our objectives were to examine (i) how the initial measurement day of the week affects 3-day and 7-day mean home BP and (ii) the BP variation between different days of the week. Participants and methodsThe study included a population sample of 1852 participants aged 44−74 years. Home BP was measured twice in the morning and evening on 7 consecutive days. The days of the week on which home BP was measured were recorded. BP means were compared with analysis of variance and the t-test. ResultsThere were no overall differences in mean systolic/diastolic BPs initiated on various days of the week (3-day means: P=0.15/0.66; 7-day means: P=0.11/0.55). Within-subject systolic/diastolic BP variation between different days of the week was small but significant (128.7±19.2–130.4±19.8/79.5±9.8–80.6±9.9 mmHg; P<0.001/<0.001). Systolic/diastolic BP was lowest during the weekend (Saturday–Sunday: 129.0±18.9/79.6±9.6 mmHg) and highest on Monday (130.4±19.8/80.6±9.9 mmHg), irrespective of the initial measurement day of the week (P for systolic/diastolic difference <0.001/<0.001). In subgroup analyses, the systolic/diastolic BP increase was greater from Saturday–Sunday to Monday among the employed than among the unemployed (1.8/1.3 vs. 0.8/0.7 mmHg; P=0.02/0.01). ConclusionSeven-day home BP measurement can be initiated on any given day of the week. However, if a 3-day measurement is taken, it is recommended to keep in mind that BP is usually the lowest during the weekend, and highest at the beginning of the week, especially among the employed.

Optimal Schedule for Assessing Home BP Variability: The Finn-Home Study

BACKGROUND Current guidelines make no recommendations on the optimal timing or number of measurements for assessing home blood pressure variability (HBPV). Our aim was to elucidate the optimal schedule for measuring HBPV in relation to cardiovascular risk. METHODS In total, 1,706 Finnish adults (56.5 ± 8.5 years; 54% women) self-measured their home blood pressure (HBP) twice in the morning and evening during 7 consecutive days. The participants were followed up for cardiovascular events. We examined the association between HBPV (coefficient of variation based on 2 through 7 measurement days) and cardiovascular events using Cox regression models adjusted for HBP and other cardiovascular risk factors. RESULTS During a follow-up of 11.8 ± 3.1 years, 216 cardiovascular events occurred. Systolic morning HBPV based on three (hazard ratio [HR], 1.039; 95% confidence interval, 1.006-1.074, model c statistic 0.737) through seven (HR, 1.057; 95% confidence interval, 1.012-1.104, model c statistic 0.737) measurement days was significantly associated with cardiovascular events. Agreement in classification to normal vs. increased morning day-to-day HBPV between consecutive measurement days became substantial (κ = 0.69 for systolic and κ = 0.68 for diastolic) after the fourth measurement day. The associations of diastolic HBPV, evening HBPV, all-day HBPV, and variability based on first measurements of each measurement occasion, with cardiovascular outcomes were nonsignificant or remained significant only after the sixth measurement day. CONCLUSIONS Our results suggest systolic HBP should be measured twice in the morning for at least 3 days when assessing HBPV. Increasing the number of measurement days from 3 to 7 results in marginal improvement in prognostic accuracy.

YIA 01-03 OUTCOME-DRIVEN REFERENCE FRAME FOR SELF-MEASURED HOME BLOOD PRESSURE VARIABILITY: INTERNATIONAL DATABASE OF HOME BLOOD PRESSURE IN RELATION TO CARDIOVASCULAR OUTCOME (IDHOCO).

Objective: Increased home blood pressure (BP) variability seems to be associated with cardiovascular disease, but the lack of operational thresholds limits its clinical application. Our aim was to define outcome-driven thresholds for day-to-day home BP variability in the general population. Design and Method: The study population consisted of 6312 community-dwelling participants from Ohasama, Japan; Tsurugaya, Japan; Didima, Greece; and Finland. The participants were divided into ten groups by deciles of home BP variability, defined as the coefficient of variation (CV) of the first measurements of each day between 5:00 and 12:00 AM to account for between-cohort differences in measurement protocols. Association between BP variability and cardiovascular mortality or cardiovascular events was assessed using Cox models adjusted for home systolic or diastolic BP, cohort, sex, age, body mass index, smoking status, diabetes status, use of antihypertensive medication, total serum cholesterol and history of cardiovascular disease. Results: Home blood pressure was measured on 22.6 ± 7.6, 15.0 ± 10.4, 3.0 ± 0.12 and 6.8 ± 0.6 days in Ohasama, Tsurugaya, Didima and Finland, respectively. During a mean follow-up of 9.3 ± 3.7 years, 306 and 720 cardiovascular deaths and events occurred, respectively. 1-SD increase in systolic/diastolic home BP variability was associated with cardiovascular mortality (Hazard ratio 1.18/1.22 [95% confidence interval 1.06 − 1.31/1.10−1.34], p = 0.003/ < 0.0001) and cardiovascular events (Hazard ratio 1.15/1.17 [95% confidence interval 1.07−1.23/1.09−1.26], p = 0.0001/<0.0001). Risk of cardiovascular deaths and events was significantly increased in the 10th decile of systolic/diastolic BP variability (CV > 10.7/12.6), as compared with the average risk in the whole population (Table). The results were similar regardless of antihypertensive treatment status. Conclusions: Home BP variability appears to be an independent risk factor for cardiovascular mortality and morbidity. Cardiovascular risk seems to increase when the systolic/diastolic CV of day-to-day home BP is greater than 10.7/12.6. Our current findings could inform guidelines and help clinicians in diagnosing and managing patients.

OS 07-06 THE ASSOCIATION BETWEEN HOME VERSUS AMBULATORY NIGHTTIME BLOOD PRESSURE AND END-ORGAN DAMAGE IN THE GENERAL POPULATION

Objective: The aim of this study was to test the agreement between nighttime home and nighttime ambulatory blood pressure (BP) and to compare their associations with hypertensive end-organ damage for the first time in the general population. Design and Method: A population sample of 248 participants underwent measurements for nighttime home BP (3 measurements on 2 nights with a timer-equipped home device), nighttime ambulatory BP, pulse wave velocity (PWV), carotid intima-media thickness (IMT) and echocardiographic left ventricular mass index (LVMI). Results: No significant differences were observed between mean nighttime home and ambulatory BPs (systolic/diastolic difference: 0.7 ± 7.6/0.2 ± 6.0 mmHg, p = 0.16/0.64). Furthermore, no systematic differences in systolic or diastolic nighttime BPs were identified between the two methods in Bland-Altman plots (Figure). All nighttime home and ambulatory BPs were positively correlated with PWV, IMT and LVMI (p < 0.01 for all). Correlation coefficients for BP indices and end-organ damage and their comparisons are shown in the Table. No significant differences in Pearsons correlation coefficients between end-organ damage and nighttime home or ambulatory BP were observed (p ≥ 0.11 for all comparisons using Dunn and Clarks Z), except for a slightly stronger correlation between PWV and ambulatory systolic BP than for home systolic BP (r = 0.57 vs. 0.50, p = 0.03). The adjusted R2 of all multivariable-adjusted models for PWV, IMT or LVMI that included nighttime home or ambulatory systolic/diastolic BP were within 2/1%. Conclusions: Our study demonstrates that nighttime home and ambulatory measurements produce similar BP values that have comparable associations with end-organ damage in the general population even when a clinically feasible measurement protocol is used for measuring nighttime home BP. In the future, nighttime home BP measurement may offer a feasible and easily accessible alternative to ambulatory monitoring for the measurement of nighttime BP.

[OP.6B.07] NIGHTTIME BLOOD PRESSURE MEASURED WITH A TIMER-EQUIPPED HOME DEVICE – AN ALTERNATIVE TO AMBULATORY MONITORING

Objective: Our objective was to test the agreement between nighttime home and nighttime ambulatory blood pressure (BP) and to compare their associations with left ventricular hypertrophy, arterial stiffness and carotid atherosclerosis. Design and method: A population sample of 248 participants underwent measurements for 24-hour ambulatory BP and nighttime home BP (3 measurements at 2, 3 and 4 hours during 2 nights). We measured ambulatory BP with a Microlife WatchBP O3 device and home BP with a timer-equipped Microlife WatchBP Home N device. In addition, the participants underwent measurement of pulse wave velocity (PWV) and ultrasonographic examinations for left ventricular mass index (LVMI) and carotid intima-media thickness (IMT). The agreement between nighttime BPs were assessed with paired t-test, intra-class correlation and Bland-Altman plots. In addition, Pearsons correlation coefficients were calculated to assess the associations between nighttime BPs and end-organ damage, and the coefficients were compared with method described by Dunn and Clark. Results: The mean number of ambulatory and home nighttime BP measurements was 16.6 ± 3.5 and 5.6 ± 1.3, respectively. No significant differences were found between mean ambulatory and home nighttime BPs (systolic/diastolic difference: 0.7 ± 7.6/0.2 ± 6.0 mmHg, p = 0.16/0.64). Furthermore, no systematic differences in systolic or diastolic nighttime BPs were identified between the two methods in Bland-Altman plots. Intra-class correlation coefficients for the relationships between systolic/diastolic nighttime BPs were high (0.81/0.71, p < 0.0001 for both). Correlation coefficients for BP indices and end-organ damage and their comparisons are shown in the Table. All home and ambulatory nighttime BP indices were positively correlated with PWV, LVMI, and IMT. The only significant difference in the correlations between end-organ damage and nighttime ambulatory or nighttime home BP, was a slightly stronger correlation between PWV and ambulatory systolic BP than for home systolic BP (p = 0.03, Table). Conclusions: We conclude that home and ambulatory monitors produce similar nighttime BP values that had comparable associations with end-organ damage. Therefore, nighttime home BP measurement can be promoted as an alternative to ambulatory monitoring for measuring nighttime BP. Figure. No caption available.