Systolic and diastolic blood pressure, pulse pressure, and mean arterial pressure as predictors of cardiovascular disease risk in Men

Association between protein-bound sialic acid and high-sensitivity C-reactive protein in essential hypertension: a possible indication of underlying cardiovascular risk

The aim of this study was to examine the possible alteration in the levels of C-reactive protein, protein-bound sialic acid, and other lipid risk factors in newly diagnosed essential hypertensive subjects. In all, 56 hypertensive and 33 normotensive male subjects were enrolled in the study. Lipid profile, C-reactive protein, apolipoprotein-B, and protein-bound sialic acid were estimated in both the groups. Total cholesterol, triglyceride, low-density lipoprotein-cholesterol, C-reactive protein, apolipoprotein-B, and protein-bound sialic acid were significantly increased in patients with essential hypertension. Correlation analysis revealed a significant association between the protein-bound sialic acid with mean arterial pressure, C-reactive protein, and low-density lipoprotein-cholesterol. The findings of the present study suggest that in essential hypertension there is an association between protein-bound sialic acid and C-reactive protein, which reflects the clustering of cardiovascular risk factors in these patients.

Derivation of the distensibility coefficient using tissue Doppler as a marker of arterial function

To date, the main cardiovascular application of TDI (tissue Doppler imaging) has been in myocardial evaluation. In the present study, we investigated the feasibility and reproducibility of assessing arterial elasticity using the DC (distensibility coefficient) measured by TDI, the correlation of this with the DC obtained by other methods and the DC in patients with various degrees of cardiovascular risk. We studied 450 subjects (256 men; age, 51±10 years) with and without risk factors of cardiovascular disease. Arterial displacement was measured from TDI, and B-mode and M-mode images of the common carotid artery in the longitudinal plane, and the DC with each method was compared. Linear regression showed a good correlation between all three methods. The results for TDI and B-mode were comparable [(21±10) compared with (21±10)×10−3/kPa respectively; P=not significant], but there were significant differences between TDI and M-mode [(21±10) compared with (31±13)×10−3/kPa respectively; P<0.0001] and between B-mode and M-mode [(21±10) compared with (31±13)×10−3/kPa respectively; P<0.0001]. Similarly, Bland–Altman analysis showed the least variability in the DC between TDI and B-mode, and there were no significant differences between the average measurements. The TDI DC also had the lowest paired difference for inter-observer variability [(−0.1±1.1)×10−3/kPa; P=not significant]. In conclusion, the results of the present study suggest that TDI of the carotid arteries is feasible, comparable with B-mode measurements, more robust than M-mode and less variable than the other methods.

A preliminary evaluation of the mean arterial pressure as measured by cuff oscillometry

BACKGROUND

The brachial artery (BA) mean blood pressure (MBP) is now readily available using the oscillometric technique. In contrast to the auscultatory method where MBP is calculated from the systolic (SBP) and diastolic blood pressure (DBP), oscillometric MBP is measured separately from either SBP or DBP. Because the peripheral MBP is free of amplification, it is nearly the same throughout the entire arterial tree and could represent the corresponding aortic pressure. The oscillometric brachial MBP could therefore serve as a surrogate for aortic MBP and might be a valuable non-invasive risk predictor.

METHODS

This study compares the oscillometric BA pressures with simultaneously and directly recorded aortic pressures in 100 patients.

RESULTS

These results show that, over a wide range of cuff pressures, the oscillometric MBP, whether alone or with age in multiple regression, predicts aortic pressure better than the SBP or DBP do, with a better correlation coefficient (r = +0.91), low aortic-cuff MBP difference (-0.79 mm Hg) and the lowest s.d. of the individual differences (+7.2 mm Hg).

CONCLUSIONS

These results are preliminary and need to be confirmed by larger studies. If confirmed, the predicted aortic pressures should be calculated and displayed by the oscillometric BP devices, the goal being to develop better non-invasive cardiovascular (CV) risk predictors.

Influence of Cardiovascular Risk Factors on Total Arterial Compliance

BACKGROUND

Reduced total arterial compliance (TAC) may be a marker of preclinical vascular disease. Irreversible risk factors such as age and body habitus are determinants of TAC, the importance of which may have been hidden by reports in selected subgroups, such as the elderly and those with diabetes mellitus or hypertension. We sought the comparative influence of reversible and irreversible risk factors on TAC in a large primary prevention group.

MATERIALS AND METHODS

We studied 720 consecutive patients with and without cardiovascular risk factors but with no overt cardiovascular disease. TAC was calculated by the pulse-pressure method from simultaneous applanation tonometry and left ventricular outflow tract Doppler. Central pressure was derived using a transfer function from the radial tonometric waveform and calibrated using mean and diastolic brachial cuff pressure.

RESULTS

There were 192 patients with no cardiovascular risk factors, 180 patients with one cardiovascular risk factor, 173 patients with two cardiovascular risk factors, and 175 patients with three or more risk factors. Although age, gender, height, weight, hypertension, diabetes mellitus, hyperlipidemia, and number of risk factors were all significantly associated with TAC, age accounted for approximately 13% of the variance, and the only other independent predictors were height and weight. TAC was not significantly different in age-matched subgroups with single risk factors.

CONCLUSION

TAC is associated with multiple risk factors, but age is a major determinant. The influence of age and other correlates may dwarf the contribution of individual risk factors and therefore their alteration with therapy.

Personal mastery predicts pain, stress, fatigue, and blood pressure in adults with rheumatoid arthritis

Among individuals with rheumatoid arthritis (RA), stress-associated disease flare can severely impact well-being. Psychological factors such as personal mastery may buffer an individual from the negative effects of those flares. We tested the hypothesis that a high sense of personal mastery would prospectively predict stress reactivity. Measures of pain,perceived stress, fatigue, and mean arterial pressure (MAP) were collected before, during, and after two interpersonal stressors conducted on 73 individuals with RA. Factor analysis of the personal mastery scale yielded two independent factors: a 5-item "fatalism" component and a 2-item "control" component. Individuals with high fatalism scores reported overall greater joint pain at baseline and those scoring high on control exhibited lower MAP, and reported less stress and fatigue at baseline. After controlling for baseline differences, those high in control exhibited greater MAP increase during stress, and less drop in pain when compared to those low in control. These results suggest that individuals high in control may be more susceptible to the effects of acute stress; however, the overall beneficial aspects of high control outweigh the acute negative effects. Personal mastery may play a role in the experience of pain, stress, and fatigue for people with RA.

Eight-year change in body mass index and subsequent risk of cardiovascular disease among healthy non-smoking men

OBJECTIVE

To determine how change in BMI over 8 years is associated with risk of subsequent cardiovascular disease (CVD) among middle aged men.

METHODS

Prospective cohort study among 13,230 healthy men (aged 51.6+/-8.7 years) in the Physicians' Health Study. BMI was collected at baseline in 1982 and after 8 years, at which time follow-up began. Subsequent CVD events were collected and confirmed through March 31, 2005. Cox proportional hazards models evaluated BMI at 8 years and risk of CVD, 8-year change in BMI and risk of CVD, and whether change in BMI added prognostic information after the consideration of BMI at 8 years.

RESULTS

1308 major CVD events occurred over 13.5 years. A higher BMI at year 8 was associated with an increased risk of CVD. Compared to a stable BMI (+/-0.5 kg/m(2)), a 0.5-2.0 kg/m(2) increase had a multivariable-adjusted RR of 1.00 (0.86-1.16). A >/=2.0 kg/m(2) increase had a multivariable-adjusted RR of 1.39 (1.16-1.68), however further adjustment for BMI reduced the RR to 1.00 (0.81-1.23). A decrease in BMI had a multivariable RR of 1.23 (1.07-1.42) which was unaffected by adjustment for BMI at 8 years.

CONCLUSION

A higher BMI and a rising BMI were both associated with an increased risk of CVD, however an increasing BMI did not add prognostic information once current BMI was considered. In contrast, a declining BMI was associated with an increased risk of CVD independent of current BMI.

A chromosome 11q quantitative-trait locus influences change of blood-pressure measurements over time in Mexican Americans of the San Antonio Family Heart Study

Although previous genome scans have searched for quantitative-trait loci (QTLs) influencing variation in blood pressure (BP), few have investigated the rate of change in BP over time as a phenotype. Here, we compare results from genomewide scans to localize QTLs for systolic, diastolic, and mean arterial BPs (SBP, DBP, and MBP, respectively) and for rates of change in systolic, diastolic, and mean arterial BPs (rSBP, rDBP, and rMBP, respectively), with use of the longitudinal data collected about Mexican Americans of the San Antonio Family Heart Study (SAFHS). Significant evidence of linkage was found for rSBP (LOD 4.15) and for rMBP (LOD 3.94) near marker D11S4464 located on chromosome 11q24.1. This same chromosome 11q region also shows suggestive linkage to SBP (LOD 2.23) and MBP (LOD 2.37) measurements collected during the second clinic visit. Suggestive evidence of linkage to chromosome 5 was also found for rMBP, to chromosome 16 for rSBP, and to chromosomes 1, 5, 6, 7, and 21 for the single-time-point BP traits collected at the first two SAFHS clinic visits. We also present results from fine mapping the chromosome 11 QTL with use of SNP-association analysis within candidate genes identified from a bioinformatic search of the region and from whole-genome transcriptional expression data collected from 1,240 SAFHS participants. Our results show that the use of longitudinal BP data to calculate the rate of change in BP over time provides more information than do the single-time measurements, since they reveal physiological trends in the subjects that a single-time measurement could never capture. Further investigation of this region is necessary for the identification of the genetic variation responsible for QTLs influencing the rate of change in BP.

How to assess mean blood pressure properly at the brachial artery level

OBJECTIVES

Mean arterial pressure at the upper arm is traditionally calculated by adding one-third of the pulse pressure to the diastolic pressure. We questioned the general validity of this formula.

METHODS

We used previously recorded resting intrabrachial pressure and Riva-Rocci Korotkoff blood pressure measurements in 57 subjects (study A) and 24-h intra-arterial recordings obtained in 22 ambulant subjects (study B).

RESULTS

In study A the intra-arterially measured 'real' mean pressure was found at 39.5 +/- 2.5% of pulse pressure above diastolic pressure, namely at a level higher than the expected 33.3% of pulse pressure, in all individuals. Results were not related to age, blood pressure, pulse pressure or heart rate levels. Mean pressure calculated with the traditional one-third rule therefore underestimated 'real' mean pressure by 5.0 +/- 2.3 mmHg (P < 0.01) when calculated from intra-arterial pressure readings, and by 4.9 +/- 5.3 mmHg (P < 0.01) when calculated from Riva-Rocci Korotkoff readings. In study B we showed activity-related variations in the relative level of the 'real' mean pressure, which increased by 1.8 +/- 1.4% (P < 0.01) during sleep, and decreased by 0.5 +/- 0.9% during walking (P < 0.05) and by 0.8 +/- 1.3% during cycling (P < 0.01).

CONCLUSION

The mean pressure at the upper arm is underestimated when calculated using the traditional formula of adding one-third of the pulse pressure to the diastolic pressure. This underestimation can be avoided by adding 40% of pulse pressure to the diastolic pressure. The proposed approach needs to be validated through larger scale studies.

Chimney stove intervention to reduce long-term wood smoke exposure lowers blood pressure among Guatemalan women

BACKGROUND AND OBJECTIVE

RESPIRE, a randomized trial of an improved cookstove, was conducted in Guatemala to assess health effects of long-term reductions in wood smoke exposure. Given the evidence that ambient particles increase blood pressure, we hypothesized that the intervention would lower blood pressure.

METHODS

TWO STUDY DESIGNS WERE USED: a) between-group comparisons based on randomized stove assignment, and b) before-and-after comparisons within subjects before and after they received improved stoves. From 2003 to 2005, we measured personal fine particle (particulate matter with aerodynamic diameter < 2.5 microm; PM(2.5)) exposures and systolic (SBP) and diastolic blood pressure (DBP) among women > 38 years of age from the chimney woodstove intervention group (49 subjects) and traditional open wood fire control group (71 subjects). Measures were repeated up to three occasions.

RESULTS

Daily average PM(2.5) exposures were 264 and 102 microg/m(3) in the control and intervention groups, respectively. After adjusting for age, body mass index, an asset index, smoking, secondhand tobacco smoke, apparent temperature, season, day of week, time of day, and a random subject intercept, the improved stove intervention was associated with 3.7 mm Hg lower SBP [95% confidence interval (CI), -8.1 to 0.6] and 3.0 mm Hg lower DBP (95% CI, -5.7 to -0.4) compared with controls. In the second study design, among 55 control subjects measured both before and after receiving chimney stoves, similar associations were observed.

CONCLUSION

The between-group comparisons provide evidence, particularly for DBP, that the chimney stove reduces blood pressure, and the before-and-after comparisons are consistent with this evidence.

Association of pulse pressure with carotid atherosclerosis in patients with type 2 diabetes mellitus

Pulse pressure is known to be a potent risk factor for cardiovascular disease. However, it has not been determined whether pulse pressure is associated with cerebrovascular disease in patients with diabetes mellitus. The purpose of the present study was to investigate association of pulse pressure with carotid atherosclerosis in patients with diabetes and to determine whether age and gender affect the association. A cross-sectional study was performed using outpatients with type 2 diabetes. Carotid atherosclerosis and arterial stiffness were evaluated by intima-media thickness of common carotid arteries (IMT) and aortic pulse wave velocity (a-PWV), respectively. The relationship of brachial pulse pressure with IMT was analyzed. Pulse pressure was significantly correlated with age, duration of diabetes, systolic blood pressure, serum sialic acid, a-PWV and IMT. The mean IMT in the highest tertile group of pulse pressure after adjustment for gender was significantly higher than the mean IMT in the lowest tertile group. In analysis using subgroups of gender, a significant correlation between pulse pressure and IMT was shown in women but not in men. In multiple regression analysis, there was a significant correlation between pulse pressure and IMT in women independently of age, body mass index, systolic blood pressure, hemoglobin A1c, atherogenic index, a-PWV, history of therapy for hypertension and history of nephropathy. The results of this study suggest that pulse pressure is a major age-independent predictor of carotid atherosclerosis in female patients with diabetes.

A new technique for assessing arterial pressure wave forms and central pressure with tissue Doppler

Background

Non-invasive assessment of arterial pressure wave forms using applanation tonometry of the radial or carotid arteries can be technically challenging and has not found wide clinical application. 2D imaging of the common carotid arteries is routinely used and we sought to determine whether arterial waveform measurements could be derived from tissue Doppler imaging (TDI) of the carotid artery.

Methods

We studied 91 subjects (52 men, age 52 ± 14 years) with and without cardiovascular disease. Tonometry was performed on the carotid artery simultaneously with pulsed wave Doppler of the LVOT and acquired digitally. Longitudinal 2D images of the common carotid artery with and without TDI were also acquired digitally and both TDI and tonometry were calibrated using mean and diastolic cuff pressure and analysed off line.

Results

Correlation between central pressure by TDI and tonometry was excellent for maximum pressure (r = 0.97, p < 0.0001). The mean differences between central pressures derived by TDI and tonometry were minimal (systolic 5.36 ± 5.5 mmHg; diastolic 1.2 ± 1.2 mmHg).

Conclusion

Imaging of the common carotid artery motion with tissue Doppler may permit acquisition of a waveform analogous to that from tonometry. This method may simplify estimation of central arterial pressure and calculation of total arterial compliance.

JNC 7 Category and Risk of Cardiovascular Death in Men: Are There Differences by Age?

The authors evaluated the seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) blood pressure classification scheme on the risk of cardiovascular disease death and whether the association varies by age. In a prospective cohort study, 53,163 apparently healthy participants aged 39-85 years were followed for 5.7 years. The authors calculated relative risks and 95% confidence intervals for cardiovascular disease death, adjusting for major risk factors, then stratified by age (39-49, 50-59, 60-69, and 70-84 years) and performed a test of heterogeneity. Compared with men with normal blood pressure, those with prehypertension had a multivariate-adjusted relative risk of 1.02 (95% confidence interval, 0.73-1.42) and those with hypertension had a relative risk of 1.54 (95% confidence interval, 1.08-2.19). There was no strong age-related effect (P(interaction), 0.22). In this large cohort, the JNC 7 categorization of prehypertension was not associated with a significantly increased risk of cardiovascular disease death, and there was no significant effect modification by age.

High pulse pressure and low mean arterial pressure: two predictors of death after a myocardial infarction

OBJECTIVES

Although the negative prognostic implication of a clinical history of arterial hypertension in myocardial infarction (MI) survivors is well known, the predictive role of the blood pressure (BP) regimen after MI is not well defined. The aim of this study was to investigate the prognostic significance of different BP indices in post-MI.

METHODS AND RESULTS

We evaluated the relationship between baseline systolic, diastolic, pulse and mean arterial pressure (MAP), measured by sphygmomanometry at discharge from hospital or within 3 months of an MI, and total and cardiovascular mortality in 11 116 patients enrolled in the GISSI-Prevenzione trial. Over 3.5 years of follow-up, 999 patients died, 657 of them from cardiovascular causes. Low mean and high pulse pressure were significantly associated with total and cardiovascular mortality after controlling for potential confounders in the multivariate analysis. As compared with patients with less extreme BP values, patients with MAP of 80 mmHg or less (n = 1241; 11.2%) had a 48% higher risk of cardiovascular death [95% confidenceinterval (CI) 1.16-1.87; P = 0.001] and those with pulse pressure greater than 60 mmHg (n = 958; 8.6%) had a 35% higher risk (95% CI 1.09-1.69; P = 0.007); only four subjects (0.04%) had both a high pulse pressure and a low MAP (relative risk of cardiovascular death 3.48; 95% CI 0.48-25.88; P = 0.218).

CONCLUSIONS

Our results show for the first time an additional prognostic importance of two easily measurable components of BP, definitely high pulse pressure (> 60 mmHg) and low MAP (< or = 80 mmHg), in a large sample of non-selected patients surviving MI who entered a modern programme of cardiovascular prevention.

Paradoxical effects of social support on blood pressure reactivity among defensive individuals

BACKGROUND

Social support can reduce cardiovascular responses to an acute stressor. However, prior clinical research suggests that defensive individuals may react negatively to social support.

PURPOSE

This experiment examined whether emotional support provided during a speech stressor would escalate rather than decrease blood pressure (BP) reactivity among defensive individuals.

METHODS

After completing personality measures, 176 female undergraduates were randomly assigned to give a speech in 1 of 3 social conditions: alone, or with a neutral or supportive confederate present. Mean arterial BP was assessed at baseline, immediately before, and during and after the stressor.

RESULTS

In the supportive condition, defensiveness predicted higher BP reactivity during anticipation (beta = .35, p = .04) and delivery of the speech (beta = .32, p = .03), and longer recovery to baseline BP levels (beta = .35, p = .01). In the absence of support (i.e., alone and neutral conditions), defensiveness was not associated with BP reactivity. Defensiveness also predicted greater dissociation between subjective stress and BP responses (beta = .35, p = .05), but only in the supportive condition.

CONCLUSIONS

According to results, the provision of social support during stressors does not benefit defensive individuals' BP reactivity but has the opposite effect.

Blood pressure as a predictor of cardiovascular events in the elderly: the William Hale Research Program

This study evaluates the association between blood pressure (BP) and the risk of developing cardiovascular disease (CVD) events in the elderly. The Morton Plant Mease Foundation has followed 4,008 elderly patients >64 years of age for at least 5 years. Systolic and diastolic blood pressure (SBP and DBP) was divided into categories. Cardiovascular disease events were classified as myocardial infarction, stroke, and CVD-related deaths reported from the National Death Index. Cox proportional hazard ratios were used to assess the relationship between BP and CVD events and controlled for weight, gender, smoker, and alcohol use. Ages <75 and >or=75 years were assessed separately. After 11.1 years of follow-up, elevated SBP (P=<0.0001) is strongly associated with developing a future CVD event; the relationship is linear and graded and holds for ages above and below 75 years. The frequency of CVD events was lowest in the SBP <120 mm Hg group. In subjects <75 years of age, DBP elevations were not a significant risk factor for CVD events. (relative risk (RR): DBP 70 to <80 mm Hg=0.92; DBP 80 to <90 mm Hg=0.88; DBP >or=90 mm Hg=1.02.) With subjects >or=75 years of age, a DBP between 80 and 90 is associated with the lowest significant risk for CVD (RR: DBP 70 to <80 mm Hg=0.74; DBP 80 to <90 mm Hg=0.59; DBP >or=90=0.71). In conclusion, these findings support the Joint National Committee on Hypertension recommendations for SBP in the elderly. Further studies are warranted to identify optimal DBP for the elderly at various ages.

Controlled-release carvedilol in the treatment of essential hypertension

Carvedilol is a beta1-, beta2-, and alpha1-adrenergic blocker that is approved for the treatment of hypertension. A new once-daily, controlled-release (CR) formulation of carvedilol has been shown to be effective in a double-blind, randomized, multicenter, placebo-controlled, parallel-group study. In this article, we summarize the primary results of, and present additional analyses from, that trial. A total of 338 patients with essential hypertension (sitting diastolic blood pressure [DBP] >/=90 and </=109 mm Hg) were randomized to receive carvedilol CR 20, 40, or 80 mg or placebo for 6 weeks. The primary objective was to compare the effects of the 3 carvedilol CR doses with placebo on 24-hour mean blood pressure using ambulatory blood pressure monitoring (ABPM). Mean DBP and systolic BP (SBP) at the drug trough (20-24 hour) blood levels for carvedilol CR and comparison of DBP and SBP at the drug peak (3-7 hour) blood levels for each dose of carvedilol CR and placebo were investigated. The effects of carvedilol CR on heart rate and pulse pressure were also examined. Once-daily administration of carvedilol CR, alone or in combination with other agents, produced clinically and statistically significant reductions compared with placebo for both DBP and SBP after 6 weeks of treatment for the following parameters: trough blood pressure by office cuff or ABPM measurements, peak blood pressure by ABPM, and 24-hour mean blood pressure by ABPM. Placebo-corrected trough-to-peak ratios for DBP were >0.6 for each carvedilol CR dose. Heart rate and pulse pressure were each significantly reduced compared with placebo for each carvedilol CR dose. We conclude that carvedilol CR is a very effective antihypertensive agent with clear dose-related peak blood pressure reduction and continuous 24-hour control.

Blood Pressure Components in Clinical Hypertension

This review offers a critical evaluation of the remarkable progress in antihypertensive therapy since its inception. Despite the introduction of newer, more sophisticated drugs, treatment results have remained stable. Problems impeding further improvement include limited patient compliance, clinical inertia, incomplete adherence to guidelines, and dependence on brachial artery cuff pressures for diagnosis, risk assessment, and treatment response. Brachial artery systolic and pulse pressures do not reliably represent aortic or carotid artery pressures, which are better risk predictors for the heart and brain. Mean pressure, which is the same throughout the arterial tree, is directly measurable by cuff oscillometry, and might become the best single risk predictor. Available drugs have limited ability to decrease the aortic stiffness that is responsible for the elevated systolic blood pressure of aging. Therefore, to improve risk assessment and therapeutic benefit, we might include mean blood pressure and pulse pressure into blood pressure measurements, pursue efforts to measure central blood pressure, and search for new drugs to reduce arterial stiffness.

Associations between submicrometer particles exposures and blood pressure and heart rate in patients with lung function impairments

OBJECTIVE

The objective of this study was to evaluate whether submicrometer particle is associated with elevated blood pressure (BP) and heart rate (HR).

METHODS

We measured ambulatory systolic BP (SBP), diastolic BP (DBP), and HR using a portable BP monitoring system and number concentrations of submicrometer particle with a size range of 0.02 to 1 microm (NC0.02-1) by a P-TRAK Ultrafine Particle Counter for 10 patients with lung function impairments.

RESULTS

We found NC0.02-1 exposures at 1- to 3-hour moving averages were associated with the elevation of SBP, DBP, and HR. There were 1.4 to 3.4-mm-Hg increases in SBP, 1.4 to 2.2-mm-Hg increases in DBP, and 0.3 to 3.5-beats/min increases in HR for 10,000 particles/cm increases in NC0.02-1 at 1- to 3-hour moving averages.

CONCLUSIONS

Exposures to submicrometer particles were associated with short-term increases in BP and HR in patients with lung function impairments.

Algorithms for converting random-zero to automated oscillometric blood pressure values, and vice versa

Many surveys and cohort studies have used a random-zero sphygmomanometer blood pressure device (RZS) to measure subjects' blood pressure and to assess the value of blood pressure in predicting cardiovascular events. Recent studies used automated oscillometric blood pressure devices (AODs) that systematically measure higher blood pressure values than RZSs do, hampering comparability of values between these studies. In 2000-2003, the authors randomly used both an RZS and an AOD in an ongoing cohort study in Germany. This analysis aimed to compare blood pressure values by device and to develop an algorithm to convert estimates of blood pressure values from one device to the other. In a randomized subset of 2,365 subjects aged 45-75 years, each subject was measured three times with each device in a randomized order. The mean difference (AOD-RZS) between the devices was 3.9 mmHg for systolic blood pressure and 2.6 mmHg for diastolic blood pressure. The authors found that linear regression models including age, sex, and blood pressure level can be used to convert RZS blood pressure values to AOD blood pressure values, and vice versa. Results may help to better compare blood pressure values in epidemiologic studies that used different blood pressure devices.

Can we improve cardiovascular risk prediction beyond risk equations in the physician's office?

BACKGROUND AND OBJECTIVES

Beyond a global estimation of the cardiovascular risk through the assessment of major risk factors and their integration in dedicated risk scales or equations, the use of specific markers provides additive prognostic information at an individual level, including predisposing factors, which are not included in the risk equations as well as the individual susceptibility to their long-term exposure. However, the majority of these markers require specific devices and skills, which are not widely available in primary care.

METHODS

Some clinical and/or "low-cost" parameters are shown to be valuable risk markers, and their use could refine the risk estimation in a physician's office. Several epidemiologic studies suggest the heart rate, the pulse pressure and the ankle-brachial index are effective cardiovascular risk markers. The arms systolic pressure asymmetry could also be a useful marker of risk.

RESULTS AND CONCLUSIONS

Through a general review, the authors evaluate the potential of these clinical markers, including their use in combination for more accurate risk determination.

Hypertension: a new look at an old problem

PURPOSE OF REVIEW

This review reports the specific impact that hypertension, identified by its component subtype classification, has on perioperative outcomes. Most importantly, we review the risk of systolic hypertension and pulse pressure hypertension independent of elevated diastolic blood pressure on patients undergoing cardiac surgery.

RECENT FINDINGS

Systemic hypertension is identified as a major risk factor for cardiovascular morbidity in most larger population-based studies. Nearly a third of the population in the United States has or will have some form of hypertension disease, with many under-diagnosed or under-treated. Classification of hypertensive subtypes has been well recognized as an important component for risk stratification in the ambulatory population in recent years, but remains poorly recognized in the surgical setting. We present recent data unveiling the importance of pulse pressure above that of systolic and diastolic pressures.

SUMMARY

The evidence is compelling that wide pulse pressure hypertension is a strong and an independent predictor of adverse perioperative renal, cerebral and mortality outcomes. We discuss the physiology for this important novel observation in an acute surgical patient population and provide an explanation.

Pulse pressure, aortic regurgitation and carotid atherosclerosis: a comparison between hypertensives and normotensives

Pulse pressure (PP) has often been associated with cardiovascular morbidity and mortality. Patients with aortic regurgitation (AR) often have increased PP. The aim of this study is to investigate the associations among PP, AR and extracranial carotid artery (ECCA) carotid atherosclerosis (CA) in hypertensives and age- and sex-matched normotensives. Two hundred and sixty-three hypertensive patients and 270 normotensive subjects from the Chin-Shan Community Cardiovascular Cohort participated in this study in 1996. CA, expressed as maximal common carotid artery intima-media thickness (IMT) > or = 75th percentile and ECCA plaque score > 6, was measured using high-resolution B-mode ultrasonography. The presence of AR was assessed by echocardiography, and their relationships with CA were evaluated. Results showed measurements of CA significantly associated with increased PP. Presence of AR associated with CA, but this relationship was attenuated after controlling for age. Multivariate logistic regression analyses revealed that an ECCA score > 6 significantly increase the risk in conjunction with PP, age and smoking in hypertensives. Correspondingly, CA increased with age, smoking and left ventricular hypertrophy on electrocardiography but not PP in normotensives. In conclusion, higher PP is strongly associated with CA in patients with hypertension. In terms of risk stratification, PP is more important in hypertensives than in normotensives which seem to imply that pulsatile haemodynamic component of BP is crucial in association with atherosclerosis.

Mean arterial pressure and systolic blood pressure for detection of hypotension during hemapheresis: implications for patients with baseline hypertension

Mean arterial pressure (MAP) has been characterized as a more sensitive and physiologically appropriate hemodynamic parameter in the detection of hemapheresis-related hypotension, resulting in a much closer correlation with the presence of symptomatic hypotension. Patients were enrolled over a 12-month period and data collected on any previous diagnosis of hypertension, antihypertensive therapy used, indication for apheresis, age decile, and gender. Baseline vital signs, any hypotensive signs or symptoms observed, and the patient's vital signs at the time of any hypotensive episode were recorded. Patients were assigned to a subgroup, sensitivity and specificity analysis performed, positive likelihood ratios calculated, receiver operating characteristic curves constructed, and ideal cutoff values identified. The incidence of hypotension among our study population was found to be 6.8%. Over all procedures, systolic blood pressure (SBP) was determined to be a "poor" test for detecting hypotension, while MAP demonstrated a "fair" capacity. A downward normalization was evident in the ideal cutoff value based upon a patient's hypertensive history. The currently accepted SBP less than 80 mmHg cutoff failed to detect hypotensive episodes among baseline hypertensive patients, raising questions about its sensitivity. Based upon physiologic principles and study findings, a MAP-based criterion is preferable in the diagnosis of hypotension during hemapheresis.

Mean aortic pressure is the geometric mean of systolic and diastolic aortic pressure in resting humans

The aim of our study was twofold: 1) to establish a mathematical link between mean aortic pressure (MAP) and systolic (SAP) and diastolic aortic pressures (DAP) by testing the hypothesis that either the geometric mean or the harmonic mean of SAP and DAP were reliable MAP estimates; and 2) to critically evaluate three empirical formulas recently proposed to estimate MAP. High-fidelity pressures were recorded at rest at the aortic root level in controls (n = 31) and in subjects with various forms of cardiovascular diseases (n = 108). The time-averaged MAP and the pulse pressure (PP = SAP - DAP) were calculated. The MAP ranged from 66 to 160 mmHg [mean = 107.9 mmHg (SD 18.2)]. The geometric mean, i.e., the square root of the product of SAP and DAP, furnished a reliable estimate of MAP [mean bias = 0.3 mmHg (SD 2.7)]. The harmonic mean was inaccurate. The following MAP formulas were also tested: DAP + 0.412 PP (Meaney E, Alva F, Meaney A, Alva J, and Webel R. Heart 84: 64, 2000), DAP + 0.33 PP + 5 mmHg [Chemla D, Hébert JL, Aptecar E, Mazoit JX, Zamani K, Frank R, Fontaine G, Nitenberg A, and Lecarpentier Y. Clin Sci (Lond) 103: 7-13, 2002], and DAP + [0.33 + (heart rate x 0.0012)] PP (Razminia M, Trivedi A, Molnar J, Elbzour M, Guerrero M, Salem Y, Ahmed A, Khosla S, Lubell DL. Catheter Cardiovasc Interv 63: 419-425, 2004). They all provided accurate and precise estimates of MAP [mean bias = -0.2 (SD 2.9), -0.3 (SD 2.7), and 0.1 mmHg (SD 2.9), respectively]. The implications of the geometric mean pressure strictly pertained to the central (not peripheral) level. It was demonstrated that the fractional systolic (SAP/MAP) and diastolic (DAP/MAP) pressures were reciprocal estimates of aortic pulsatility and that the SAP times DAP product matched the total peripheral resistance times cardiac power product. In conclusion, although the previously described thumb-rules applied, the "geometric MAP" appears more valuable as it established a simple mathematical link between the steady and pulsatile component of aortic pressure.

Clinical review: interpretation of arterial pressure wave in shock states

In critically ill patients monitored with an arterial catheter, the arterial pressure signal provides two types of information that may help the clinician to interpret haemodynamic status better: the mean values of systolic, diastolic, mean and pulse pressures; and the magnitude of the respiratory variation in arterial pressure in patients undergoing mechanical ventilation. In this review we briefly discuss the physiological mechanisms responsible for arterial pressure generation, with special focus on resistance, compliance and pulse wave amplification phenomena. We also emphasize the utility of taking into consideration the overall arterial pressure set (systolic, diastolic, mean and pulse pressures) in order to define haemodynamic status better. Finally, we review recent studies showing that quantification of respiratory variation in pulse and systolic arterial pressures can allow one to identify the mechanically ventilated patients who may benefit from volume resuscitation.

Long-term prognostic impact of repeated measurements over 1 year of pulse pressure and systolic blood pressure in the elderly

Systolic blood pressure (SBP) and pulse pressure (PP) have been identified in western industrialized countries as major predictors of cardiovascular events in the elderly on the basis of measurements taken at a single visit. Considering the wide variability of blood pressure (BP) in older people, this study set out to assess the prognostic significance of measurements of SBP and PP taken over several months according to a monitoring scheme mimicking routine care. A total of 444 Italian general practitioners enrolled a cohort of 3858 unselected elderly outpatients and followed them up for 10 years. BP was recorded at recruitment, 1 week later and at quarterly visits during the first year. The average BP of these six visits was used to define the patient's BP status. During the 10-year follow-up, 1561 participants died, 709 from cardiovascular diseases. Proportional hazard regression analysis, adjusted for all main prognostic factors including antihypertensive treatment, showed that for each 10-mmHg increment in SBP and PP there were, respectively, 5 and 9% increases in risk for total mortality (TM) and 9 and 13% increases in risk for cardiovascular mortality (CVM) (all P < 0.01). However, including both SBP and PP in the model, only PP showed an independent, significant relationship with TM and CVM. In conclusion, prognostic information based on repeated measurements of PP is stronger than that given by SBP and consequently should be recommended in the definition of cardiovascular risk in the elderly.

Hypertension Control as Predictor of Mortality in Treated Men and Women, Followed for up to 30 Years

PURPOSE

To examine the prognosis of treated, hypertensive individuals in the Reykjavik Study.

METHODS

A population-based longitudinal study of 9328 men and 10 062 women. Subjects were included in the study during the period 1967-1996. Two groups of treated, hypertensive subjects were defined at baseline: with controlled blood pressure and with uncontrolled blood pressure. Main outcome measures were cardiovascular disease (CVD) mortality and all-cause mortality.

RESULTS

Of the hypertensive men 24.8% were treated, and of those 38.3% were controlled, and of the hypertensive women 45.3% were treated, and of those 52.7% were controlled. Comparing treated and uncontrolled (systolic blood pressure (SBP) > or =160 mmHg and/or diastolic blood pressure (DBP) > or =95 mmHg) versus treated and controlled hypertensive subjects, followed for up to 30 years, the uncontrolled men and women were at significantly higher risk of CVD mortality, hazard ratio (HR) = 1.47 (95% confidence interval (CI): 1.06-2.02) and HR 1.70 (CI: 1.23-2.36), respectively, showing the benefit of hypertension control. The risk of all-cause mortality was increased for treated, uncontrolled men and women, compared with those who were treated and controlled, but did not reach significance. When analyzing blood pressure as a continuous variable among treated, hypertensive subjects, SBP was a better predictor than DBP of CVD mortality and all-cause mortality in women. This was not the case in men.

CONCLUSIONS

Control of blood pressure among hypertensive-treated subjects at baseline was associated with a lower risk of CVD mortality during follow-up. SBP was the single best predictor of CVD mortality and all-cause mortality in treated women. The uncontrolled women were at a higher risk than the uncontrolled men.

Effects of nifedipine GITS and diuretics in isolated systolic hypertension--a subanalysis of the INSIGHT study

AIMS

This study tested the effects on cardiovascular outcomes of treatments based on nifedipine gastrointestinal therapeutic system (GITS) compared with the diuretic combination co-amilozide in a pre-specified subset of patients with isolated systolic hypertension (ISH) enrolled in the International Nifedipine GITS Study: Intervention as a Goal in Hypertension Treatment (INSIGHT) study.

MAJOR FINDINGS

Of 6321 randomized patients, 1498 (23.7%) had ISH with a baseline mean BP of 173/88 mmHg in both treatment groups. Mean BP fell by 29/10 mmHg in the nifedipine and 30/10 mmHg in the diuretic group to a mean BP of 144/78 mmHg and 143/79 mmHg, respectively, at endpoint. The percentage of primary outcomes in patients with ISH was not significantly different between the two treatment groups (nifedipine GITS 6.0%, co-amilozide 6.6%). The number of ISH patients with composite secondary outcomes was 90 (12.2%) in the nifedipine GITS group and 110 (14.5%) in the co-amilozide group (not significant). The incidence rates of primary and secondary outcomes were similar in patients without ISH.

CONCLUSION

In patients with ISH, nifedipine GITS and co-amilozide had similar effects on clinical outcomes and BP lowering. They lend support to international guidelines for the treatment of hypertension recommending the use of long-acting dihydropyridine calcium-channel blockers as one treatment option for patients with ISH.

Heritability of ambulatory and office blood pressure phenotypes in Swedish families

OBJECTIVE

The aim of this study was to estimate the heritability of 24-h ambulatory blood pressure and office blood pressure phenotypes in Swedish families.

METHODS

We measured ambulatory and office blood pressure in 260 siblings without antihypertensive treatment from 118 families. Blood pressure heritability was estimated using standard quantitative genetic variance component analysis implemented in the 'SOLAR' software package after adjustment for significant covariates.

RESULTS

Heritability values were significant for night-time systolic (37%), diastolic (32%) and mean (32%) ambulatory blood pressure (P < 0.05 for all). During daytime, systolic ambulatory blood pressure was significantly heritable (33%, P < 0.05). Twenty-four-hour systolic (30%) and diastolic (29%) ambulatory blood pressure also had significant values of heritability (P < 0.05). Pulse pressure ambulatory blood pressure was significantly heritable over 24 h (63%, P < 0.01), during daytime (53%, P < 0.01) and at night (34%, P < 0.05). None of the office blood pressure phenotypes had a significant heritability.

CONCLUSIONS

We conclude that ambulatory blood pressure, in particular at night, seems better than office blood pressure to capture the heritable part of blood pressure, suggesting that ambulatory blood pressure may be a more exact estimate of an individual's true blood pressure. Genetic studies using ambulatory blood pressure as the phenotype are likely to be more powerful than those using office blood pressure. The high heritability of pulse pressure ambulatory blood pressure indicates that variation in arterial stiffness in subjects free from antihypertensive medication is strongly affected by genetic factors.

Gender-specific association between pulse pressure and C-reactive protein in a Chinese population

There is growing evidence that low-grade chronic inflammation, as reflected by the raised serum concentration of C-reactive protein, might be a risk factor for hypertension, in particular in women. We therefore investigated gender-specific associations of systolic and diastolic blood pressure and pulse pressure with serum C-reactive protein concentration in a Chinese population sample. In 463 participants, we measured serum C-reactive protein concentration using a high-sensitivity immunonephelometric latex-enhanced assay. We performed single and multiple linear regression analyses. The 224 male and 239 female subjects were of similar age (51.0 years) and had similar levels of systolic blood pressure (124.7 mmHg) and pulse pressure (47.1 mmHg), but men, compared with women, had higher diastolic blood pressure (79.6 vs 75.8 mmHg; P<0.0001) and body mass index (24.3 vs 23.4 kg/m2; P=0.003). Both before and after adjustment for age, age2, body mass index, current smoking, alcohol intake, and use of antihypertensive drugs, pulse pressure was significantly associated with serum C-reactive protein concentration in women (P< or =0.002) but not in men (P>0.10; P=0.02 for interaction between gender and serum C-reactive protein). In women, with one-fold increase in serum C-reactive protein concentration, pulse pressure was 1.94 mmHg higher. The categorical analyses confirmed our findings. With similar adjustments applied, women in the fourth quartile, compared with those in the lowest quartile, had a 7.6 mmHg higher pulse pressure (95% confidence interval 3.5-11.7 mmHg; P=0.0003). Furthermore, when women were analysed according to menopausal status, the association between pulse pressure and C-reactive protein was only significant in postmenopausal (P< or =0.04), but not in premenopausal, subjects (P> or =0.21). In conclusion, taken together with the previous gender-specific observations on carotid lesions and hypertension, our finding suggests that chronic low-grade inflammation might play a role in the widening of pulse pressure in Chinese women. This cross-sectional observation warrants further investigation in prospective studies.

Advanced glycation endproduct crosslinking in the cardiovascular system: potential therapeutic target for cardiovascular disease

Advanced glycation endproducts (AGEs) are formed by a reaction between reducing sugars and biological amines. Because of their marked stability, glycated proteins accumulate slowly over a person's lifespan, and can contribute to age-associated structural and physiological changes in the cardiovascular system such as increased vascular and myocardial stiffness, endothelial dysfunction, altered vascular injury responses and atherosclerotic plaque formation. The mechanisms by which AGEs affect the cardiovascular system include collagen crosslinking, alteration of low-density lipoprotein molecules and impairment of cellular nitric oxide signalling through their interaction with AGE receptors (RAGEs). Thus, the accumulation of AGEs may help to explain the increased cardiac risk associated with aging as well as diabetes mellitus and hypertension, two conditions that accelerate and enhance AGE formation. A variety of new pharmacological approaches are being developed to reduce the pathophysiological impact of AGEs. These agents can prevent AGE and AGE crosslink formation, break pre-existing AGE crosslinks, and block the interaction between AGEs and RAGEs. Such agents have been shown to reduce vascular and myocardial stiffness, inhibit atherosclerotic plaque formation and improve endothelial function in animal models. Improvement in vascular compliance has also been demonstrated with AGE crosslink breakers in clinical trials. These studies offer promise to reduce the cardiac risk associated with isolated systolic hypertension, diastolic dysfunction and diabetes.

Estimation of pressure pulse amplification between aorta and brachial artery using stepwise multiple regression models

The pressure pulse is amplified between the aorta and peripheral sites. This study compares two methods to estimate pressure pulse amplification (PPA) between the aorta and the brachial artery. Method 1: PPA was determined from a multi-parameter linear regression of subject parameters (gender, age, height, weight, heart rate (HR), brachial systolic pressure (BSP), diastolic pressure (BDP), mean pressure (MP)). Method 2: PPA was calculated from central aortic pressure waveforms (CW) estimated from the same subject parameters. The sample population (1421 male, 992 female) was selected from a database where aortic pressure was estimated by mathematical transformation of a peripheral (radial) pulse calibrated to sphygmomanometric BSP and BDP. The two methods were consistent in showing HR and MP as the most important parameters to estimate PPA. Correlation coefficients (R2) of 0.48 (method 1) and 0.44 (method 2) were obtained using height, weight, HR, BSP, BDP and age. Inclusion of MP increased R2 to 0.77 (method 1) and 0.71 (method 2). This study shows that databases containing peripheral and central aortic pressure waveforms can be used to construct multiple regression models for PPA estimation. These models could be applied to studies of similar subject groups where peripheral waveforms may not be available.

Achievement of target blood pressure levels in chronic kidney disease: a salty question?

A large body of evidence supports the validity of lowering blood pressure (BP) to prevent cardiovascular (CV) disease in the general population. This issue becomes even more critical in renal patients because they carry a greater CV risk across the entire spectrum of chronic kidney disease (CKD). In these patients, achievement of lower BP levels also is fundamental to limit the progression of renal damage, especially in the presence of significant proteinuria. Although expert panels have strongly recommended to intensively decrease BP in patients with CKD, management of hypertension in these patients remains inadequate. Armed with the knowledge of the extreme salt-sensitivity of BP in patients with CKD, it is reasonable to hypothesize that more aggressive treatment of volume expansion can be helpful. Nevertheless, although abundant literature has evidenced that dietary sodium restriction decreases BP levels in patients with essential hypertension, no large and prospective study has been conducted to date on this issue in patients with CKD. A potential reason is the low compliance of patients with CKD to dietary prescriptions; however, this problem can be overcome by specific counseling. Alternatively, loop diuretics administered at a high dose should represent the cornerstone of therapy, but, again, well-designed studies verifying the effectiveness of these agents in a large CKD population are still awaited. Nephrologists seem to be reluctant to adequately administer diuretics because of the fear of adverse events. Conversely, the major detrimental effect, that is, excessive hypovolemia, can be prevented if daily body weight loss is limited to 0.3 to 0.5 kg during the initial period of treatment.

Managing hypertension in African-American patients

Epidemiologic evidence indicates that African Americans are at greater risk for hypertension compared with other ethnic groups in the United States. The prevalence of hypertension is estimated to be approximately 37% for this group, compared with 20%-25% for non-Hispanic whites. Hypertension seems to follow a more malignant course in African Americans, possibly as a result of the higher prevalence of concomitant cardiovascular risk factors in this population. Compared with white persons with hypertension, these patients are at increased risk for left ventricular hypertrophy, heart failure, and end-stage renal disease. Data suggest that ethnicity may influence the response to certain types of antihypertensive medication. Additional data indicate that more aggressive use of combination therapy may improve clinical outcomes among high-risk hypertensive patients. Based on these findings, recommendations are made for the optimal clinical management of hypertension in African-American patients.

Blood pressure measures and electrocardiogram-defined myocardial infarction in an Iranian population: Tehran Lipid and Glucose study

The purpose of this study was to describe blood pressure values in Iranian adults with electrocardiogram (ECG) evidence of a myocardial infarction (MI). High blood pressure is a risk factor, and an ECG can be diagnostic of coronary artery disease. In recent studies the role of pulse pressure in predicting coronary artery disease has been suggested to be more important than that of blood pressure. From among participants of the Tehran Lipid and Glucose study, data for 2479 men and 3060 women aged > or =30 years not currently using any antihypertensive medication were collected. The study used the mean of two separate blood pressure measurements for each individual. ECG findings of all subjects were coded according to Minnesota ECG coding criteria, and they were categorized into probable/possible MI or no MI. ECG evidence of probable or possible MI was found in 1.2% of subjects (1.8% in men vs. 0.8% in women, p<0.001). Prevalence of ECG-defined MI in hypertensive persons was two-fold higher than in normotensives. Adjusted for age, sex, and body mass index, mean diastolic blood pressure was significantly lower in cases with ECG-defined MI than in subjects without MI (p<0.03). There was a strong positive correlation between pulse pressure and systolic blood pressure in both hypertensive/normotensive and MI/no MI groups at the p<0.001 level. There was a weak inverse correlation between diastolic blood pressure and pulse pressure in hypertensive/normotensive/no MI groups (-0.32 and -0.14, both p<0.001). Diastolic blood pressure was not correlated with pulse pressure in cases with MI. Prevalence of ECG-defined MI in hypertensive cases was higher than in normotensives. Systolic blood pressure is a better predictor for pulse pressure than diastolic blood pressure in both normotensive and hypertensive populations with or without ECG-defined MI.

Pulse pressure is associated with age and cardiovascular disease in type 1 diabetes

OBJECTIVE

Type 1 diabetic individuals are thought to have increased arterial stiffness, and are at high risk for cardiovascular disease. However, it is not known whether increased arterial stiffness in type 1 diabetes causes cardiovascular disease. To explore this issue, the present study investigated the association, in type 1 diabetes, of age and pulse pressure, an estimate of arterial stiffness, and the influence of the presence of microvascular complications on this association. In addition, we determined the association of mean arterial pressure and pulse pressure with incident cardiovascular disease.

METHODS

We studied a cohort of 3250 type 1 diabetic individuals of the EURODIAB Prospective Complications Study. Mean age and median follow-up were 33 and 7.4 years. One hundred and sixty-three individuals developed a first manifestation of cardiovascular disease during follow-up. Linear regression analysis was used to determine the association of age with pulse pressure. Relative risks of cardiovascular disease were estimated by Cox regression analyses adjusted for age, sex and mean arterial pressure or pulse pressure.RESULTS In cross-sectional analyses, age was associated with pulse pressure (P < 0.001) and this association was stronger in the presence of micro- or macroalbuminuria or retinopathy than in their absence (interaction for albuminuria, P < 0.001; interaction for retinopathy, P < 0.001). In prospective analyses, both mean arterial pressure and pulse pressure were associated with cardiovascular disease [adjusted relative risks and (95% confidence interval) per 10 mmHg increase were 1.08 (0.94-1.24) and 1.09 (0.98-1.21)].

CONCLUSIONS

This study shows an association of age with pulse pressure in young type 1 diabetic individuals, which is stronger in the presence of microvascular complications. In addition, both mean arterial pressure and pulse pressure are associated with incident cardiovascular disease. These findings support the concept of early vascular ageing in type 1 diabetes, especially in the presence of microvascular complications.

Mean arterial pressure (MAP): an alternative and preferable measurement to systolic blood pressure (SBP) in patients for hypotension detection during hemapheresis

Current protocols utilize systolic blood pressure (SBP) of less than 80 mmHg as objective evidence of hypotension during hemapheresis. However, tissue hypoperfusion is the pathophysiologic endpoint of low blood pressure, and mean arterial pressure (MAP), rather than SBP, is the physiologic driving force behind blood flow to organs and tissues. It is thus hypothesized that MAP is more appropriate than SBP in the assessment of hypotension and that a threshold MAP can be utilized as a sensitive indicator of hypotension during hemapheresis. Thirty-one patients who experienced hypotension during hemapheresis over a 4.5 year period reflecting forty-four hypotensive episodes were selected. The initial phase of each hemapheresis procedure provided baseline MAP and blood pressure (BP) measurements as control values. BP and MAP were then determined at the onset of subjective hypotension and compared to one another by using regression and sensitivity analyses. Correlation coefficients between SBP and MAP were found to be 0.8097 in baseline normotensive patients and 0.7725 in hypotensive patients. Sensitivity in the detection of hypotension was 0.09% for SBP equal to 80 mmHg and 56.81% for MAP equal to 70 mmHg. An SBP of 80 mmHg or less was therefore concluded to be a less sensitive and physiologically less appropriate measurement of hypotension than MAP. As a single value less than 70 mmHg or a series of successive measurements trending downward toward 70 mmHg, MAP provides an objective assessment of hypotension that may precede hemodynamic decompensation.

The effect of low-dose potassium supplementation on blood pressure in apparently healthy volunteers

Epidemiological and clinical trials suggest an inverse relationship between dietary K intake and blood pressure (BP). Most trials however have been of short duration, the dose of K was high, and the results have been conflicting. The aim of the present study was to evaluate the effect on BP of a low-dose supplementation (24 mmol/d) for an extended period. A double-blind placebo-controlled trial was conducted on fifty-nine volunteers, randomly assigned to receive 24 mmol slow-release KCl/d (n 30) or a placebo (n 29). Measures of BP, anthropometric characteristics and urine analysis for electrolytes were recorded during a 1-week baseline period. Supplementation was for 6 weeks during which BP and changes in weight were assessed and a second 24 h urine collection made. The primary outcome was the change in mean arterial pressure (MAP); systolic BP (SBP) and diastolic BP (DBP) were secondary outcomes. After 6 weeks of supplementation MAP was reduced by 7.01 (95 % CI -9.12, -4.89; P<0.001) mmHg, SBP was reduced by 7.60 (95 % CI -10.46, -4.73; P<0.001) mmHg and DBP was reduced by 6.46 (95 % CI -8.74, -4.19; P<0.001) mmHg. The reduction in MAP was positively associated with baseline urinary Na:K (P<0.034). A low daily dietary supplement of K, equivalent to the content of five portions of fresh fruits and vegetables, induced a substantial reduction in MAP, similar in effect to single-drug therapy for hypertension.

Uncontrolled hypertension as a risk for coronary artery disease: patient characteristics and the role of physician intervention

Hypertension is the most widely treated cardiovascular risk factor, and there is clear evidence of the efficacy of treating systolic and diastolic blood pressure with existing antihypertensive agents in reducing stroke and cardiac disease. However, only about 25% of the US population has blood pressure controlled to at least 140 mm Hg systolic and 90 mm Hg diastolic. Hypertension control is a complex function of patient and physician behavior. Although poor hypertension control has historically been attributed to lack of health insurance or low utilization of available services, recently published analyses of national survey data and local physician and community samples suggest that physicians have a permissive attitude toward isolated mild systolic blood pressure elevations in the range of 140 to 160 mm Hg. The great majority of participants in health surveys report seeing a physician at least two times per year, and several investigators have documented that physicians are unlikely to increase treatment intensity for systolic elevations alone. Physician inaction toward elevated systolic blood pressure may be due to a reluctance to prescribe multiple drugs and/or lack of belief in the benefits of aggressive treatment to lower systolic blood pressure below 140 mm Hg.

Blood pressure and decline in kidney function: findings from the Systolic Hypertension in the Elderly Program (SHEP)

The association between BP and decline in kidney function in older persons and the BP component most responsible for kidney disease are unknown. This study investigated the relationship between baseline BP and an incident decline in kidney function among 2181 men and women enrolled in the placebo arm of the Systolic Hypertension in the Elderly Program (SHEP). A decline in kidney function was defined as an increase in serum creatinine equal to or greater than 0.4 mg/dl over 5 yr of follow-up. The incidence and relative risk of a decline in kidney function increased at higher levels of BP for all BP components, independent of age, gender, ethnicity, smoking, diabetes, and history of cardiovascular disease. Systolic BP imparted the highest risk of decline in kidney function. The adjusted relative risk (95% confidence interval) associated with the highest compared with the lowest quartile of BP was 2.44 (1.67 to 3.56) for systolic; 1.29 (0.87 to 1.91) for diastolic; 1.80 (1.21 to 2.66) for pulse; and 2.03 (1.39 to 2.94) for mean arterial pressure. The risk associated with systolic BP remained strong in models containing other BP components, while diastolic, pulse, and mean arterial pressure had no significant association with a decline in kidney function in models containing systolic BP. Therefore, systolic BP is a strong, independent predictor of a decline in kidney function among older persons with isolated systolic hypertension.

Pulse pressure and coronary mortality in elderly men and women from general population

The aim of this work was to evaluate whether pulse pressure (PP) in elderly people is a better predictor of coronary mortality than systolic and diastolic blood pressure taken alone. For this aim, 3282 elderly subjects aged >or=65 years were studied in a population-based frame. Blood pressure was repeatedly measured and averaged; historical data, anthropometrics, blood tests and 14-year coronary mortality were recorded. Statistics included analysis of covariance, Cox analysis and bivariate vectorial analysis. Coronary mortality in women was predicted by PP (1.01 excess risk/mm Hg PP) and was significantly higher in the 3rd than in the 1st tertile of PP (relative risk 2.90); neither systolic nor diastolic pressure taken alone influenced mortality. When systolic and diastolic pressures were both entered into a Cox model, the former had a positive and the latter a negative effect on survival, confirming a prognostic role of PP. For any given level of systolic pressure, mortality was inversely associated with diastolic pressure. Finally, the mean vector representing both systolic and diastolic pressures of non-surviving women was characterised by higher systolic and lower diastolic components than in non-surviving. No significant trend of mortality in relation to either systolic blood pressure or PP was observed in men. In conclusion, the combination of systolic and diastolic pressure called PP is an independent predictor of coronary mortality in elderly females, and a better predictor than systolic or diastolic pressure alone.