Comparison of three blood pressure measurement methods for the evaluation of two antihypertensive drugs: feasibility,agreement, and reproducibility of blood pressure response

Our objective was to compare three different methods of blood pressure measurement through the results of a controlled study aimed at comparing the antihypertensive effects of trandolapril and losartan. Two hundred and twenty-nine hypertensive patients were randomized in a double-blind parallel group study. After a 3-week placebo period, they received either 2 mg trandolapril or 50 mg losartan once daily for 6 weeks. At the end of both placebo and active treatment periods, three methods of blood pressure measurement were used: a) office blood pressure (three consecutive measurements); b) home self blood pressure measurements (SBPM), consisting of three consecutive measurements performed at home in the morning and in the evening for 7 consecutive days; and c) ambulatory blood pressure measurements (ABPM), 24-h BP recordings with three measurements per hour.Of the 229 patients, 199 (87%) performed at least 12 valid SBPM measurements during both placebo and treatment periods, whereas only 160 (70%) performed good quality 24-h ABPM recordings during both periods (P < .0001). One hundred-forty patients performed the three methods of measurement well. At baseline and with treatment, agreement between office measurements and ABPM or SBPM was weak. Conversely, there was a good agreement between ABPM and SBPM. The mean difference (SBP/DBP) between ABPM and SBPM was 4.6 ± 10.4/3.5 ± 7.1 at baseline and 3.5 ± 10.0/4.0 ± 7.0 at the end of the treatment period. The correlation between SBPM and ABPM expressed by the r coefficient and the P values were the following: at baseline 0.79/0.70 (< 0.001/< .0001), with active treatment 0.74/0.69 (0.0001/.0001). Hourly and 24-h reproducibility of blood pressure response was quantified by the standard deviation of BP response. Compared with office blood pressure, both global and hourly SBPM responses exhibited a lower standard deviation. Hourly reproducibility of SBPM response (10.8 mm Hg/6.9 mm Hg) was lower than hourly reproducibility of ABPM response (15.6 mm Hg/11.9 mm Hg).In conclusion, SBPM was easier to perform than ABPM. There was a good agreement between these two methods whereas concordance between SBPM or ABPM and office measurements was weak. As hourly reproducibility of SBPM response is better than reproducibility of both hourly ABPM and office BP response, SBPM seems to be the most appropriate method for evaluating residual antihypertensive effect.     

Prognostic value of home blood pressure measurement

Although self-monitoring of blood pressure by patients at home is being widely used in clinical practice, the evidence on its prognostic value is still limited. Five long-term studies with nearly 60,000 patients/year have provided prognostic information for home blood pressure measurements. Differences exist among these studies regarding the population characteristics, the sample size and follow-up, the methodology and protocol for office and home blood pressure measurement and the adjustment procedure for other risk factors. All these studies, nevertheless, showed systolic home blood pressure to be a significant predictor of cardiovascular risk, and three of them also showed prognostic value of diastolic home blood pressure. Moreover, the prognostic value of home blood pressure appeared to be consistently superior to that of conventional office measurements. The prognostic significance of the white coat and the masked hypertension phenomena detected by home measurements were investigated in two studies, one in treated hypertensive patients and another in a general population sample. These studies showed that patients with white-coat phenomenon have similar cardiovascular risk as those with low office and home blood pressure, whereas the masked hypertension phenomenon is associated with high risk as in patients with uncontrolled hypertension. In conclusion, the available evidence suggests that home blood pressure has strong prognostic value, which appears to be superior to that of the conventional office measurements. More outcome studies on the prognostic value of home blood pressure, however, are needed.     

Effects of intravenous nicardipine on blood pressure, hemorheology platelet function in arterial hypertension. Dose-effect relations

In arterial hypertension, hyperviscosity with hemorheological disturbances and platelet dysfunction may play a role in the prognosis and complications of the disease. We studied the effects of Nicardipine (NIC) on these blood disturbances in a group of 21 untreated patients with essential hypertension, aged 25 to 70 years (SBP/DBP = 185 +/- 28/105 +/- 17 mmHg). During one hour before and 4 hours after the IV injection of single doses of 5, 7.5 or 10 mg NIC over 5 min, blood pressure was recorded automatically (Dinamap). Hemorheological variables and platelet function were studied before and 30 min, 3 h and 24 hours after the injection. NIC lowered blood pressure and increased heart rate significantly (At 5 min, SBP = -24 mmHg; DBP = -18 mmHg; HR = +22 b/min). These effects were dose-dependent with rapid onset and short duration (less than 2 hrs). NIC decreased plasma viscosity from 1.36 +/- 0.08 to 1.30 +/- 0.07 Cst; p less than 0.01, whole blood viscosity from 22.4 +/- 2.8 to 20.7 +/- 1.5 mPas; p less than 0.05 for gamma = 0.512 s-1, and erythrocyte filterability with the Ca++ ionophore A 23187 from 16.3 +/- 3.8 to 13.5 +/- 3.1; p less than 0.01. Platelet aggregation with ADP was unchanged, but aggregation with A 23187 decreased from 46.9 +/- 21.2 to 31.3 +/- 25.6; p less than 0.05, as well as plasma levels of beta-thromboglobulin (71.2 +/- 29.8 to 55.4 +/- 24.3 ng/ml; p less than 0.02) and platelet generated malonaldehyde (7.2 +/- 1.8 to 6.7 +/- 1.4 nM/10(9) platelets; NS).(ABSTRACT TRUNCATED AT 250 WORDS)     

血细胞对静脉溶栓治疗的急性缺血性卒中患者转归的预测价值

越来越多的研究表明,外周血细胞计数,包括中性粒细胞、嗜酸性粒细胞、单核细胞、淋巴细胞、红细胞、血小板计数以及相关比值,与急性缺血性卒中患者静脉溶栓后的临床转归相关。因此,作为预测卒中患者转归的生物标志物,外周血细胞计数及相关比值具有重要的临床应用价值。文章对血细胞计数及相关比值对急性缺血性卒中患者静脉溶栓后转归的预测价...     

累积血压暴露对新发心房颤动的预测价值

目的探讨累积血压暴露(cumBP)对新发心房颤动(AF)的预测价值。方法本研究采用前瞻性队列研究的方法,观察对象为唐山开滦集团员工,自2006年开始每隔2年进行1次体检,截止至2015年底,共进行了5次体检。前3次体检均参加且血压等基线资料完整的研究对象为57927例。排除既往AF病史者、随访时心电图资料缺失者,最终纳入统计学分析的观察对象为40727例。根据累积收缩压暴露(cumSBP)进行四分位数分组:第一分位组:cumSBP464 mmHg·year;第二分位组:464 mmHg·year≤cumSBP512 mmHg·year;第三分位组:512 mmHg·year≤cumSBP569 mmHg·year;第四分位组:cumSBP≥569 mmHg·year。比较不同cumSBP组新发AF的情况。COX比例风险模型分析cumBP对新发AF的预测价值。结果 (1)40727例观察对象,平均年龄51.81±11.54岁,其中男性30693例(75.4%),女性10034例(24.6%)。(2)结果表明,男性比例和年龄、体质指数、空腹血糖、总胆固醇和尿酸水平均随cumSBP的增加而增加,各组间差异有统计学意义(P0.05)。(3)平均随访4.97±0.37年,影响新发AF事件的多因素COX比例风险模型分析显示:校正其他混杂因素后,cumSBP每增加10 mmHg·year,发生新发AF的HR值为1.034(95%CI 1.012～1.057);累积舒张压暴露每增加5 mmHg·year,发生新发AF的HR值为1.026(95%CI 1.008～1.044)。结论 cumBP对新发AF具有预测价值。     

Prognostic value of blood pressure in acute stroke

Manipulation of blood pressure (BP) in acute stroke may improve outcome. Despite various studies, data on the prognostic significance of early BP in stroke remain unclear. Therefore, we studied the relationship between various BP variables in the acute phase of stroke and functional outcome at 3 months. Blood pressures were collected by reviewing BP records of 817 patients who were admitted to our stroke unit between 1987 and 1992. Besides the first systolic and diastolic admission BP (SBP and DBP), we also used the mean of the daytime as well as the night-time systolic and diastolic BP values. Finally, we studied the relationship between the decrease in BP between day 0 and 4 and outcome. As dependent outcome variable we used the Rankin handicap score at 3 months dichotomized in a score >3 (poor outcome) vs a score 3 (good outcome). A total of 430 patients were admitted within 24 h following stroke onset. There was no significant relationship between the systolic and diastolic BP and the outcome at 3 months. Only night-time systolic BP 165 mm Hg (odds ratio (OR) 2.8; 95% CI 1.1-6.8), night-time diastolic BP 60 mm Hg (OR 8.1; 95% CI 1.1-58.3), and a decrease in daytime diastolic BP between day 0 and 4 of 10 mm Hg (OR 3.0; 95% CI 1.1-7.9) showed a significant relationship with poor outcome. Our findings suggest that admission BP values may not reliably reflect any impact of BP on stroke outcome. They also suggest a potential differential effect of BP manipulation: increasing or decreasing BP may be beneficial for patients with BP extremes in one direction, but detrimental for those with BP values in the opposite direction.     

Relationships among blood pressures obtained using different measurement methods in the general population of Ohasama, Japan.

To examine the relationships between casual, ambulatory and home blood pressure measurements in the general population, these measurements were obtained in 1,695 of 3,744 subjects aged 20 yr or older in Ohasama, Japan. Of these 1,695 subjects, 1,207 measured their home blood pressure more than 14 times in each of the morning and evening (881 untreated subjects including normotensives and untreated hypertensives, 56.4 +/- 11.5 yr of age; 326 treated subjects, 66.0 +/- 9.2 yr of age). We analyzed data in these 1,207 subjects, examining the distribution of each measurement, the relationships among measurements, and the factors affecting the blood pressure differences among the measurements. For systolic pressure, the casual measurement was the highest among the methods examined. The daytime ambulatory measurement was significantly higher than morning and evening home measurements. Morning home measurements were significantly higher than those in the evening. For diastolic pressure, however, the morning home measurement was the highest among the methods examined. Short-term pressure variability (standard deviation and variation coefficient of ambulatory measurements) was greater than long-term pressure variability (standard deviation and variation coefficient of home measurements). The pressure variability in treated subjects was greater than that in untreated subjects. The correlation between casual pressure and the other pressures was not as strong (r<0.567). Among the relationships between ambulatory and home measurements, the strongest correlation was observed between the 24-h ambulatory measurement and the morning home measurement (r=0.738) in untreated subjects. The morning home measurement was highly correlated with the evening home measurement (r>0.814). The differences among the methods examined were affected by blood pressure level and age. It should be noted that in elderly and treated subjects, blood pressure measurement using one method does not necessarily correlate with that obtained using the other methods. This information is useful for the estimation of the value of one type of blood pressure measurement from values obtained with other methods.     

Comparison of different methods of blood pressure measurements

OBJECTIVE: To compare different methods of measuring and averaging blood pressure readings, and see how they affect classification of patients as normotensive or hypertensive. METHODS: The comparisons were made in up to 145 suitable patients in the first and last week of a 6-week surveillance. Ambulatory blood pressure measurements were taken from the nondominant arm, as the average of up to 78 measurements over 24 h (24-h ambulatory blood pressure measurements), or 60 from 0700 h to 2200 h (daytime ambulatory blood pressure measurements), or 18 from 2200 h to 0700 h (night-time ambulatory blood pressure measurements). Office blood pressure measurements were taken by the outpatient department nurse in triplicate from both arms, and the averages were taken of the second and third of each triplicate. Home blood pressure measurements were taken in duplicate each morning and evening, entered by patients into diaries, and the available readings of up to four values per day were averaged for the first and sixth week. The classifications of normotensive versus hypertensive produced by criterion values of 24-h ambulatory blood pressure measurements of 125/80 and 130/80 mmHg were compared with the classifications produced by the other measurements with a range of criterion values. RESULTS: The home blood pressure measurements and office blood pressure measurements of systolic values underestimated the corresponding 24-h ambulatory blood pressure measurements values by 3-9 average (SD 9-18) mmHg, and the diastolic values overestimated them by averages of 3-6 (SD 6-13) mmHg. Daytime ambulatory blood pressure measurement systolic and diastolic values overestimated them by 2-4 (SD 2-4) mmHg and night-time ambulatory blood pressure measurement values underestimated them by 7-12 (SD 5-9) mmHg. In comparing the 24-h ambulatory blood pressure measurement classifications of hypertensives versus normotensives with those produced from the other types of measurements, it was easiest to detect criterion values for daytime ambulatory blood pressure measurement that gave the best agreement and they appeared different for the different criterion values of 24-h ambulatory blood pressure measurement. For the other types of measurement, the agreement was generally worse and it was harder to detect a best criterion value for agreement with either of the 24-h ambulatory blood pressure measurement classifications. A subsample of 63 patients identified as needing institution, maintenance or modification of antihypertensive treatment excluded about half of the patients classified as hypertensive by either 24-h ambulatory blood pressure measurement criterion. CONCLUSION: Limited agreement existed between different ways of classifying patients. The utility of the classifications depends on the purpose to which they are put.     

腹腔内压测定对危重型急性胰腺炎预后的判断价值

目的 分析危重型急性胰腺炎(CAP)的临床特点,探讨腹腔压力(IAP)、APACHEⅡ评分对CAP患者预后预测的价值.方法 筛选2010年1月至2013年3月发病96 h内入住南京军区南京总医院普外科ICU的18～75岁AP患者,其中47例符合根据决定因素的AP分类(determinant-based classification,DBC)中的CAP诊断标准.对这些患者在入院24 h内行APACHEⅡ评分,并测量IAP.记录器官功能衰竭发生情况、中转手术引流例数、入住ICU时间、总住院时间.应用受试者工作特征曲线下面积(AUC)分析IAP、APACHEⅡ评分预测患者预后和中转手术的价值,及其与入住ICU时间、总住院时间的相关性.结果 47例患者入院24h的平均APACHEⅡ评分为13分,平均IAP为16.9 mmHg(1mmHg =0.133 kPa),血培养阳性22例.发生呼吸系统衰竭45例次(96％),肾功能衰竭34例次(72％),心血管功能衰竭22例次(47％),其中出现2、3个器官系统功能衰竭的患者分别为16、19例.17例(36％)患者接受手术引流.院内病死18例(38％).平均入住ICU 31 d,平均总住院时间38 d.IAP水平和APACHEⅡ评分随衰竭器官系统数量的增加逐渐升高,差异具有统计学意义(P＜0.001).IAP水平预测患者病死的AUC为0.80(95％ CI 0.41 ～0.76),以16.1 mmHg为阈值,其敏感性、特异性分别为83％和62％;APACHEⅡ评分预测的AUC为0.58(95％ CI0.38～0.73),以13.5分为阈值,其敏感性、特异性分别为44％和73％.IAP水平预测患者病死的敏感性高于APACHEⅡ评分,两者预测中转手术的敏感性均较低,与患者入住ICU时间、总住院时间均无相关性.结论 CAP具有极高的手术率和病死率.早期监测IAP可以有效预测预后较差的CAP患者.     

Predictive value of clinic blood pressure variability for pressure changes during placebo in elderly hypertensives

OBJECTIVES: Syst-China is the ongoing placebo-controlled double-blind outcome trial in older (aged 60 years or more) Chinese patients with isolated systolic hypertension (systolic blood pressure 160-219 mmHg and diastolic blood pressure < 95 mmHg). This article is based on the data accumulated until 31 August 1992. Its purpose is to investigate the extent to which the variability in the clinic blood pressure readings at baseline could predict the blood pressure changes observed in the placebo arm of the trial. METHODS: From 2379 patients recruited into the trial, 728 [455 men and 273 women, aged 66.7+/-5.5 years (mean +/- SD)] were selected, because their blood pressure readings for the three run-in visits as well as 3, 6 and 12 months after random allocation were available. Overall and between-visit blood pressure variabilities at baseline were estimated from the two readings obtained with the subject seated during the first and second run-in visits. The baseline blood pressure used to calculate the blood pressure changes during follow-up was the average of the two readings during the third run-in visit. RESULTS: The blood pressure variability at baseline was larger for women than it was for men. For all of the subjects combined, the blood pressure had decreased by 4.1+/-14.4 mmHg (P < 0.001) systolic and 0.5+/-6.7 mmHg (P < 0.06) diastolic by the 3-month follow-up visit, by 8.5+/- 15.2 and 1.4+/-7.5 mmHg, respectively, after 6 months and by 10.3+/-15.7 and 1.9+/-7.9 mmHg, respectively, after 1 year (p < 0.001 for all). Stepwise multiple regression analysis showed that sex, age, alcohol intake and the blood pressure at baseline were significant determinants of the long-term (1 year) blood pressure changes. Aftger adjustment for the aforementioned covariates, the between-visit variability was a significant predictor of the changes in the diastolic blood pressure after 1 year of placebo treatment for the men (partial r+/-SEM -0.36+/-0.12, P < 0.01) and for all of the subjects (-0.19+/-0.09, P < 0.05). For men, the partial regression coefficient between the overall variability and the changes in the diastolic blood pressure also attained statistical significance (-0.39+/- 0.14, P < 0.01). CONCLUSION: For older Chinese patients with isolated systolic hypertension, in particular for men, a higher blood pressure variability at baseline was associated with a larger decrease in diastolic blood pressure during 1-year follow-up on placebo, explaining up to 2% of the variance of the observed changes. Similar associations were not observed for systolic blood pressure.     

Pseudohypertension and the measurement of blood pressure.

Riva-Rocci Korotkoff (RRK) blood pressure measurements may overestimate the intra-arterial pressure (IAP) in individual patients. To study pseudohypertension, defined as an overestimation larger than 10 mm Hg, we compared RRK and IAP measurements in 76 patients. These patients were considered to be at risk for pseudohypertension because of high age, hypertension, or vascular disease. RRK measurements underestimated simultaneously measured systolic IAP values by 6.0 +/- 6.5 (mean +/- SD) mm Hg, whereas simultaneous diastolic RRK readings overestimated the IAP by 1.9 +/- 5.6 mm Hg. Diastolic overestimation increased slightly with age. Vascular rigidity, as measured by counterpressure plethysmography, did not correlate with these errors. Systolic and diastolic pseudohypertension was observed in two and five patients, respectively. Pseudohypertension was only present in the group in which IAP was measured in the aorta. However, the number of patients with systolic and diastolic pseudohypertension could be increased to three and seven by using the average intra-arterial systolic and diastolic pressure during an RRK measurement or to six and 11 by using the IAP during a control period just before an RRK measurement rather than the IAP at the moment of appearance or disappearance of the Korotkoff sounds. The widely diverging prevalence of pseudohypertension described in the literature might be explained because of such different comparison techniques.     

Comparative assessment of four blood pressure measurement methods in hypertensives

Introduction

Discordance between blood pressure (BP) measurement methods can occur and create ambiguity. New automated office BP monitors (AOBPs) are widely available, but their role is presently unclear. The objectives of this study are to quantify concordance among BP measurement methods and to define the diagnostic sensitivity, specificity, and predictive value of AOBPs in a population of hypertensive patients.

Methods

The office mercury sphygmomanometer, the AOBP, an ambulatory BP monitor (ABPM), and home self-measurement with an automatic device were compared in a randomized, crossover study. BP averages and achievement of therapeutic goals were defined. Comparisons and agreement tests were performed. Diagnostic indices were calculated for the AOBP.

Results

A total of 101 patients were enrolled. Average BP results were similar between measurement methods with the exception of daytime ABPM, which was significantly higher; figures are mean ± standard deviation (SD): sphygmomanometer, 129.9 ± 13.7/80.9 ± 9.3 mm Hg; AOBP, 128.4 ± 13.9/80.0 ± 9.4 mm Hg; 24-hour ABPM, 131.4 ± 11.7/78.7 ± 9.7 mm Hg; day ABPM, 135.5 ± 11.4/82.0 ± 11.9 mm Hg; home self-measurement, 131.0 ± 14.3/82.5 ± 8.2 mm Hg. Discordance in the achievement of therapeutic goals was observed in 58 patients, with only 26 cases being explained by masked hypertension or “white coat syndrome” according to all measurements. Disagreement was greater when office methods were compared with ambulatory methods.

Conclusions

This study shows that the 4 measurement strategies provide similar average BP estimates but generate many discordant results. The AOBP device can be very valuable as a replacement for the sphygmomanometer.     

Blood pressure response to antihypertension treatment. Comparison of data obtained at the doctor's office and by ambulatory blood pressure measurement

A comparative study of clinical and ambulatory responses to antihypertensive treatment was conducted retrospectively in 69 patients with mild to moderate arterial hypertension. The patients received different drugs, but blood pressure (BP) was measured by the same methods in each of them. (a) Clinical BP was measured with a mercury manometer some time after taking the last dose of antihypertensive drug: 24 hours in patients who took one daily dose, 12 hours in those who took two daily doses. (b) Ambulatory BP was measured with a Spacelabs SPM 5200 instrument over a minimum of 24 hours. The parameters compared were: (1) BP figures recorded. Correlation was very poor as regards both SBP (r = 0.42 before treatment, r = 0.55 after treatment) and DBP (r = 0.40 and r = 0.46 respectively). The mean BP value was lower in the ambulatory group than in the clinical group (-20/-12 mmHg), the difference being slightly less marked after treatment (-12/-6 mmHg). (2) Degree of absolute reduction of BP induced by treatment. Correlation was very poor between the two methods as regards both SBP (r = 0.46) and DBP (r = 0.49). (3) Proportion of responders and non-responders to treatment, the clinical response being defined as normalization and/or more than 10 p. 100 reduction of DBP, and the ambulatory response as a significant decrease of mean diastolic value over 24 hours. Among the 69 patients studied, there were 51 concordant cases (36 responders, 15 non-responders with the two methods) and 18 discordant cases (10 clinical responders but ambulatory non-responders, 8 clinical non-responders but ambulatory responders).(ABSTRACT TRUNCATED AT 250 WORDS)     

Predictive role of the nighttime blood pressure

Numerous studies addressed the predictive value of the nighttime blood pressure (BP) as captured by ambulatory monitoring. However, arbitrary cutoff limits in dichotomized analyses of continuous variables, data dredging across selected subgroups, extrapolation of cross-sectional studies to prospective outcomes, and lack of comprehensive adjustments for confounders make interpretation of the literature difficult. We reviewed prospective studies with total mortality or a composite cardiovascular end point as an outcome in relation to the level and the circadian profile of systolic BP. We analyzed studies in hypertensive patients (n = 23 856) separately from those in individuals randomly recruited from populations (n = 9641). We pooled summary statistics and individual subject data, respectively. In both patients and populations, in analyses in which nighttime BP was additionally adjusted for daytime BP and vice versa, nighttime BP was a stronger predictor than daytime BP. With adjustment for the 24-hour BP, both the night-to-day BP ratio and dipping status remained significant predictors of outcome but added little prognostic value over and beyond the 24-hour BP level. In the absence of conclusive evidence proving that nondipping is a reversible risk factor, the option whether or not to restore the diurnal blood pressure profile to a normal pattern should be left to the clinical judgment of doctors and should be individualized for each patient. Current guidelines on the interpretation of ambulatory BP recording need to be updated.     

Immunoglobulin response to intravenous streptokinase in acute myocardial infarction.

OBJECTIVE--To devise assays to assess and follow the specific antibody response in patients treated with streptokinase for acute myocardial infarction. DESIGN--Venous blood samples were collected before treatment with streptokinase started and subsequently at regular intervals over one year. Specific IgG and subclass IgG1 were assessed by an enzyme linked immunosorbent assay. SETTING--Coronary care unit in a general hospital. PATIENTS--48 patients with acute myocardial infarction: 22 patients had venous blood samples taken at presentation only; serial blood samples were taken from 20 patients who then received thrombolytic therapy with streptokinase and six patients who were unsuitable for thrombolytic therapy. RESULTS--Titres of antibodies to streptokinase were low at presentation in 36 (75%) of the 48 patients. Serial measurements made in 20 patients showed the virtual disappearance of antibody within the first 24 hours. This was followed by a steady increase in the specific IgG1 titre, which peaked at day 14 before gradually declining. Values at one year remained significantly higher than baseline values. There was no evidence of an IgM response in the patients studied. CONCLUSION--Low titres of antibodies to streptokinase were widespread in the population. Antibody was consumed after treatment and the subsequent immunoglobulin rise suggested a secondary immune responses; the recently described neutralising capacity to streptokinase is probably related to this antibody.