Our aim was to assess the prognostic significance of nighttime and daytime ambulatory blood pressure and their ratio for mortality and cause-specific cardiovascular events in hypertensive patients ...without major cardiovascular disease at baseline. We performed a meta-analysis on individual data of 3468 patients from 4 prospective studies performed in Europe. Age of the subjects averaged 61+/-13 years, 45% were men, 13.7% smoked, 8.4% had diabetes, and 61% were under antihypertensive treatment at the time of ambulatory blood pressure monitoring. Office, daytime, and nighttime blood pressure averaged 159+/-20/91+/-12, 143+/-17/87+/-12, and 130+/-18/75+/-12 mm Hg. Total follow-up amounted to 23 164 patient-years. We used multivariable Cox regression analysis to assess the hazard ratios associated with 1 standard deviation higher blood pressure. Daytime and nighttime systolic blood pressure predicted all-cause and cardiovascular mortality, coronary heart disease, and stroke, independently from office blood pressure and confounding variables. When these blood pressures were entered simultaneously into the models, nighttime blood pressure predicted all outcomes, whereas daytime blood pressure did not add prognostic precision to nighttime pressure. Appropriate interaction terms indicated that the results were similar in men and women, in younger and older patients, and in treated and untreated patients The systolic night-day blood pressure ratio predicted all outcomes, which only persisted for all-cause mortality after adjustment for 24-hour blood pressure. In conclusion, nighttime blood pressure is in general a better predictor of outcome than daytime pressure in hypertensive patients, and the night-day blood pressure ratio predicts mortality, even after adjustment for 24-hour blood pressure.
Given the increasing use of ambulatory blood pressure monitoring (ABPM) in both clinical practice and hypertension research, a group of scientists, participating in the European Society of ...Hypertension Working Group on blood pressure monitoring and cardiovascular variability, in year 2013 published a comprehensive position paper dealing with all aspects of the technique, based on the available scientific evidence for ABPM. The present work represents an updated schematic summary of the most important aspects related to the use of ABPM in daily practice, and is aimed at providing recommendations for proper use of this technique in a clinical setting by both specialists and practicing physicians. The present article details the requirements and the methodological issues to be addressed for using ABPM in clinical practice, The clinical indications for ABPM suggested by the available studies, among which white-coat phenomena, masked hypertension, and nocturnal hypertension, are outlined in detail, and the place of home measurement of blood pressure in relation to ABPM is discussed. The role of ABPM in pharmacological, epidemiological, and clinical research is also briefly mentioned. Finally, the implementation of ABPM in practice is considered in relation to the situation of different countries with regard to the reimbursement and the availability of ABPM in primary care practices, hospital clinics, and pharmacies.
Ambulatory blood pressure monitoring (ABPM) is being used increasingly in both clinical practice and hypertension research. Although there are many guidelines that emphasize the indications for ABPM, ...there is no comprehensive guideline dealing with all aspects of the technique. It was agreed at a consensus meeting on ABPM in Milan in 2011 that the 34 attendees should prepare a comprehensive position paper on the scientific evidence for ABPM.This position paper considers the historical background, the advantages and limitations of ABPM, the threshold levels for practice, and the cost-effectiveness of the technique. It examines the need for selecting an appropriate device, the accuracy of devices, the additional information and indices that ABPM devices may provide, and the software requirements.At a practical level, the paper details the requirements for using ABPM in clinical practice, editing considerations, the number of measurements required, and the circumstances, such as obesity and arrhythmias, when particular care needs to be taken when using ABPM.The clinical indications for ABPM, among which white-coat phenomena, masked hypertension, and nocturnal hypertension appear to be prominent, are outlined in detail along with special considerations that apply in certain clinical circumstances, such as childhood, the elderly and pregnancy, and in cardiovascular illness, examples being stroke and chronic renal disease, and the place of home measurement of blood pressure in relation to ABPM is appraised.The role of ABPM in research circumstances, such as pharmacological trials and in the prediction of outcome in epidemiological studies is examined and finally the implementation of ABPM in practice is considered in relation to the issue of reimbursement in different countries, the provision of the technique by primary care practices, hospital clinics and pharmacies, and the growing role of registries of ABPM in many countries.
Cobalt oxide (Co3O4) nanoparticles were synthesized from aqueous solutions of cobalt(II) acetate using a laboratory scale continuous hydrothermal flow synthesis reactor incorporating a confined jet ...(coaxial) mixer. By changing the concentration of the precursor combined with operating under flow rate conditions expected to result in a laminar or turbulent mixing, the size of the crystallites could be controlled in the range of 6.5–16.5 nm (median). A quench stream was employed to rapidly cool down the nascent stream of nanoparticles and to elucidate the mechanisms of nucleation and growth. The results show a clear correlation between increasing precursor concentration and crystallite size, which at lower concentrations in particular, decreased in laminar flow and increased in turbulent flow. The smallest particles of 6.5 nm (median) were produced at a precursor concentration of 0.1 M (at a rate of 20 g·h–1). The materials were characterized using a range of analytical methods including powder X-ray diffraction and transmission electron microscopy.
It is uncertain whether ambulatory blood-pressure measurements recorded for 24 hours in patients with treated hypertension predict cardiovascular events independently of blood-pressure measurements ...obtained in the physician's office and other cardiovascular risk factors.
We assessed the association between base-line ambulatory blood pressures in treated patients and subsequent cardiovascular events among 1963 patients with a median follow-up of 5 years (range, 1 to 66 months).
We documented new cardiovascular events in 157 patients. In a Cox proportional-hazards model with adjustment for age, sex, smoking status, presence or absence of diabetes mellitus, serum cholesterol concentration, body-mass index, use or nonuse of lipid-lowering drugs, and presence or absence of a history of cardiovascular events, as well as blood pressure measured at the physician's office, higher mean values for 24-hour ambulatory systolic and diastolic blood pressure were independent risk factors for new cardiovascular events. The adjusted relative risk of cardiovascular events associated with a 1-SD increment in blood pressure was 1.34 (95 percent confidence interval, 1.11 to 1.62) for 24-hour ambulatory systolic blood pressure, 1.30 (95 percent confidence interval, 1.08 to 1.58) for ambulatory systolic blood pressure during the daytime, and 1.27 (95 percent confidence interval, 1.07 to 1.57) for ambulatory systolic blood pressure during the nighttime. For ambulatory diastolic blood pressure, the corresponding relative risks of cardiovascular events associated with a 1-SD increment were 1.21 (95 percent confidence interval, 1.01 to 1.46), 1.24 (95 percent confidence interval, 1.03 to 1.49), and 1.18 (95 percent confidence interval, 0.98 to 1.40).
In patients with treated hypertension, a higher ambulatory systolic or diastolic blood pressure predicts cardiovascular events even after adjustment for classic risk factors including office measurements of blood pressure.
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