Mean Awake Blood Pressure Research Articles

PROGNOSTIC VALUE OF AWAKE AND ASLEEP AMBULATORY BLOOD PRESSURE FOR PREDICTION OF CARDIOVASCULAR MORBIDITY: RESULTS OF THE MAPEC STUDY: PP.3.90

Objectives: Target organ damage and cardiovascular risk are more closely associated with ambulatory (ABPM) than with clinic blood pressure (BP). Moreover, it has been suggested that nighttime BP is a better predictor of risk than daytime or 24 h BP. All previous trials on the prognostic value of ABPM have relied only on a single baseline profile from each participant, without accounting for changes in BP during follow-up. We have compared to prognostic value of ABPM and clinic BP in the MAPEC study, where participants were systematically evaluated by repeated ABPM. Methods: This prospective study investigated 3344 subjects (1718 men), 52.6 ± 14.5 years of age. At baseline, BP was measured every 20-min from 07:00 to 23:00 h and every 30-min at night for 48 h. Just before starting ABPM, six clinic BP measurements were obtained with a validated oscillometric device. ABPM was scheduled yearly or more frequently (quarterly) if treatment adjustment was required. The Cox proportional-hazard model was used to estimate relative risks of cardiovascular events associated to clinic and ambulatory BP. Results: After a median follow-up time of 5.6 years, ambulatory BP predicted outcome better than clinic BP. Moreover, the asleep BP mean was consistently a stronger predictor than the awake or 24 h BP mean. Based on the baseline ABPM, with adjustment for gender, age, diabetes, antihypertensive treatment, and clinic BP, the relative hazard ratio (HR) for each 10-mmHg increase in systolic BP was 1.18 (1.09–1.28; P < 0.001) for awake mean and 1.29 (1.21–1.37; P < 0.001) for asleep mean. Cardiovascular morbidity was even more strongly associated with systolic asleep BP when data were analyzed on the basis of the ABPM profile closer to the event (1.30, 1.23–1.38, P < 0.001). Conclusions: ABPM is superior to clinic BP in predicting cardiovascular morbidity and mortality. After adjustment for relevant confounding risk factors, the asleep BP mean provides higher prognostic value than awake BP mean. Results further indicate that decreasing asleep BP reduces cardiovascular risk beyond 24h-mean BP lowering.

RATIO NIGHT/DAY OF BLOOD PRESSURE AS A MARKER OF INJURY ATHEROSCLEROTIC VASCULAR: PP.31.251

Objective: To analyze the relationship between ratio night/day of systolic blood pressure and arterial stiffness assessed with carotid intima-media thickness, pulse wave velocity and Augmentation Index. Methods: Design: Cross-sectional study. Setting and Participants: 262 hypertensive patients < 75 years included by consecutive sampling. Average age 54.96 ± 11.58 years, 61.5% males. Measurements: Monitoring ambulatory blood pressure (BP) of 24 hours and estimate systolic and diastolic ratio night/day. Pulse wave velocity (PWV), central blood pressure and Augmentation index (AIx) measured with the SphygmoCor System. Carotid intima-media thickness (IMT) measured with ultrasound. Results: The mean awake BP were 129.45/79.85 mmHg and asleep BP 114.26/66.30 mmHg. IMT mean was 0.74 ± 0.12 mm, and the maximum mean 0.91 ± 0.14 mm. PWV was 9.09 ± 2.21 m/sec. Increase aortic pressure was 14.16 ± 8.82 mmHg, Central pulse pressure (PP) 43.83 ± 13.66 mmHg, Central AIx 30.57 ± 13.30, Central AIx adjusted FC 75 l/m 28.95 ± 11.18 and Peripheral AIx 92.49 ± 21.13. We found positive correlation of systolic ratio night/day with IMT mean (r = 0.268, p = 0.000), IMT maximum mean (r = 0.279, p = 0.000), PWV (r = 0.226, p = 0.000), aortic PP (r = 0.281, p = 0.000), increased central blood pressure (r = 0.234, P = 0.000) and central AIx (0.153, p = 0.013). In multiple linear regression (Stepwise) after adjusting for age, sex and antihypertensive drugs, and considering as dependent variable the ratio night / day, persists in equation, central PP and IMT maximum mean. Conclusions: Ratio night/day of systolic blood pressure was positively associated with markers of arterial stiffness and could be a predictor of atherosclerotic vascular injury.

A primary care pragmatic cluster randomized trial of the use of home blood pressure monitoring on blood pressure levels in hypertensive patients with above target blood pressure

The measurement of blood pressure (BP) at home by patients with hypertension is increasingly used to assess and monitor BP. Evidence for its effectiveness in improving BP control is mixed. To determine if home BP monitoring improves BP a pragmatic cluster randomized contolled trial was carried out in family practices in southeastern Ontario, Canada. Family practice patients with uncontrolled hypertension were recruited to the trail. Patients were divided into two groups: one with at least weekly measurements of BP at home, recording those measurements and showing those to the family physician during office visits for hypertension and the control group were given usual care. The primary outcome was mean awake BP on ambulatory monitoring at 6- and 12-month follow-up and the secondary outcomes were mean BP on full 24-hour ambulatory blood pressure monitoring (ABPM), mean sleep BP on ABPM and BP on the BpTRU device, all at 6- and 12-month follow-up. Home BP monitoring did not improve BP compared to usual care at 12-month follow-up: mean awake systolic BP on ABPM [141.1 versus 142.8 mmHg, mean difference 1.7 mmHg; 95% confidence interval (CI) -0.6 to 4.0, P = 0.314] and mean awake diastolic BP on ABPM (78.7 versus 79.4 mmHg, mean difference 0.7 mmHg; 95% CI -7.7 to 9.1, P = 0.398). Similar negative results were obtained for men and women separately. However, outcomes using the full 24-hour ABPM and the BpTRU device showed a significantly lower diastolic BP at 12 months. When analysis was done by sex, this effect was shown to be only in men. Home BP monitoring may improve BP control in men with hypertension.

Relation of Hemodynamic Volume Load to Arterial and Cardiac Size

Objectives. This study sought to assess the relation of Doppler stroke volume (SV) to cardiac and carotid artery size and to determine whether volume load accounts for the parallelism between the two.Background. It has been suggested that altered hemodynamic volume load can modify the degree and pattern of left ventricular (LV) hypertrophy from that predicted from blood pressure (BP) alone.Methods. We related Doppler echocardiographic SV in 342 normotensive or unmedicated asymptomatic hypertensive adults to echocardiographic LV mass, LV internal dimension (LVID), wall thickness, carotid ultrasound arterial lumen diameter, intimal–medial thickness (IMT) and cross-sectional area (CSA).Results. SV was positively related to LV mass (r = 0.42), LVID (r = 0.45), ventricular wall thickness (r = 0.20 to 0.29) and carotid diameter (r = 0.23, all p < 0.0001); CSA (r = 0.17, p < 0.002); and IMT (r = 0.12, p = 0.03). In multivariate analyses controlling for awake ambulatory BP and the circumferential end-systolic stress/end-systolic volume index ratio, SV remained an independent predictor of LV mass and chamber size (both p < 0.0001) but not LV wall thickness. SV also predicted carotid diameter (p < 0.0002), CSA (p = 0.001) and, to a lesser degree, IMT (p = 0.02) after controlling for mean awake BP and age. In additional analyses, LV and carotid dimensions were significantly interrelated independent of SV.Conclusions. SV measured by invasively validated Doppler echocardiography is associated with LV and carotid artery enlargement and eccentric hypertrophy, independent of arterial pressure, LV contractility, age and body size; however, SV and other variables do not account for the previously documented parallelism between cardiac and arterial structure.(J Am Coll Cardiol 1997;29:1303–10)

A chronotherapeutic approach to the management or hypertension

Patients with hypertension have a characteristic circadian pattern of blood pressure (BP) variability in a 24-h period, characterized by a wide range while awake and active, and a narrower range during sleep and inactivity. Blood pressure in the untreated hypertensive individual declines by approximately 10% to 20% during sleep compared with the mean awake BP values. Early in the morning (assuming a typical day-night activity cycle), the BP rises sharply on awakening, when physical and mental activities increase. Antihypertensive therapy has been traditionally dosed in the morning after awakening, and in recent years most of the newly developed antihypertensive agents have been once-daily, long-acting preparations. However, theoretically, this pattern of drug dosing may be suboptimal since pharmacodynamic activity is attenuated at the end of the dosing period, when a large rise in BP may occur. Presently, only a few studies have been performed to evaluate the effects of nocturnal dosing of standard long-acting drugs. Consequently, we undertook an assessment of the effects of a new formulation of verapamil--controlled onset extended release verapamil HCl (COER-24)--that is dosed nocturnally and has a controlled onset of delivery (4 to 5 h postdose) and an extended release for the remainder of the dosing period. Through ambulatory BP monitoring, evaluation revealed that this verapamil formulation produced changes in BP that followed the circadian rhythm of BP: lower reductions during sleep, when the BP is intrinsically lowest, and appropriately larger reductions during the early morning and daytime hours, when ambulatory BP values accelerate and plateau to their highest levels. These data demonstrate that it is possible to design antihypertensive therapy for once-nightly dosing, thereby providing a chronotherapeutic regimen for patients with hypertension.

A Chronotherapeutic Approach to the Management of Hypertension

Patients with hypertension have a characteristic circadian pattern of blood pressure (BP) variability in a 24-h period, characterized by a wide range while awake and active, and a narrower range during sleep and inactivity. Blood pressure in the untreated hypertensive individual declines by approximately 10% to 20% during sleep compared with the mean awake BP values. Early in the morning (assuming a typical daynight activity cycle), the BP rises sharply on awakening, when physical and mental activities increase. Antihypertensive therapy has been traditionally dosed in the morning after awakening, and in recent years most of the newly developed antihypertensive agents have been once-daily, long-acting preparations. However, theoretically, this pattern of drug dosing may be suboptimal since pharmacodynamic activity is attenuated at the end of the dosing period, when a large rise in BP may occur. Presently, only a few studies have been performed to evaluate the effects of nocturnal dosing of standard long-acting drugs. Consequently, we undertook an assessment of the effects of a new formulation of verapamilontrolled onset extended release verapamil HC1 (COER-24)—that is dosed nocturnally and has a controlled onset of delivery (4 to 5 h postdose) and an extended release for the remainder of the dosing period. Through ambulatory BP monitoring, evaluation revealed that this verapamil formulation produced changes in BP that followed the circadian rhythm of BP: lower reductions during sleep, when the BP is intrinsically lowest, and appropriately larger reductions during the early morning and daytime hours, when ambulatory BP values accelerate and plateau to their highest levels. These data demonstrate that it is possible to design antihypertensive therapy for once-nightly dosing, thereby providing a chronotherapeutic regimen for patients with hypertension. Am J Hypertens 1996;9:29S–33S