Inter-arm blood pressure differences compared with ambulatory monitoring: a manifestation of the 'white-coat' effect?

Simultaneously measured inter-arm blood pressure difference is not associated with pulse wave velocity in a clinical dataset of at-risk hypertensive patients

Recent analysis of systolic inter-arm differences in blood pressure from the INTERPRESS-IPD Collaboration suggest an association with increased all-cause mortality, cardiovascular mortality and cardiovascular events. Previous studies have demonstrated associations with other risk parameters. We aimed to reproduce these associations in a cohort of 199 treated, at-risk hypertensive patients with pulse wave velocity (PWV) as a surrogate marker of cardiovascular (CV) damage. Simultaneously measured inter-arm blood pressure (BP) differences, 24 hour ambulatory BP and PWV were measured in 199 treated patients from a tertiary hospital hypertension outpatient clinic. Associations between systolic inter-arm BP difference and PWV were analyzed with uni- and multi-variate regression models. Out of 199 participants, 90 showed an inter-arm BP difference of more than 5 mmHg. The inter-arm difference was not associated with PWV. Furthermore, neither observed single BP measurements nor 24 hour ambulatory BP was associated with inter-arm BP differences. In our clinical patient cohort we failed to observe an association between inter-arm BP differences and PWV. Mode of assessment, study design and the sample characteristics of this treated, hypertensive cohort may have contributed to the negative findings. The limited sample size of the study poses a challenge to the detection of smaller effects in our study.

Inter-arm difference in blood pressure in patients referred to tertiary hypertension center: Prevalence, risk factors, and relevance to physicians

The prevalence of inter-arm BP difference is high in hypertension and is associated with adverse cardiovascular outcomes. We performed a retrospective chart review of prevalent patients in the Ottawa Hospital Hypertension Center to assess for prevalence, risk factors, and whether finding of inter-arm BP difference >10 mmHg leads to investigations of the aorta and aortic arch. Inter-arm BP difference among 493 patients was present in 16.2% (95% confidence interval [CI]13.3-19.9%), and it was associated with presence of peripheral arterial disease. Physicians did not investigate ascending aorta and aortic arch for causes of the clinically significant inter-arm BP difference.

Usefulness of four-limb blood pressure measurement in prediction of overall and cardiovascular mortality in acute myocardial infarction

Four-limb blood pressure measurement could improve mortality prediction in the elderly. However, there was no study to evaluate whether such measurement was still useful in predicting overall and cardiovascular (CV) mortality in acute myocardial infarction (AMI). Two hundred AMI patients admitted to cardiac care unit were enrolled. The 4-limb blood pressures, inter-limb blood pressure differences, and ankle brachial index (ABI) were measured using an ABI-form device. The median follow-up to mortality was 64 months (25th-75th percentile: 5-174 months). There were 40 and 138 patients documented as CV and overall mortality, respectively. After multivariable adjustment, the ankle diastolic blood pressure (DBP) on the lower side, ABI value, ABI < 0.9, interarm DBP difference, interankle systolic blood pressure (SBP) and DBP differences, interankle SBP difference ≥ 15 mmHg, and interankle DBP difference ≥ 10 mmHg could predict overall mortality (P ≤ 0.025). The ankle DBP on the lower side, interankle DBP difference, and interankle DBP difference ≥ 10 mmHg could predict CV mortality (P ≤ 0.031). In addition, in the Nested Cox model, the model including the ankle DBP on the lower side and the model including interankle DBP difference had the best value for overall and CV mortality prediction, respectively (P ≤ 0.031). In AMI patients, 4-limb blood pressure measurement could generate several useful parameters in predicting overall and CV mortality. Furthermore, ankle DBP on the lower side and interankle DBP difference were the most powerful parameters in prediction of overall and CV mortality, respectively.

Interarm Difference in Systolic Blood Pressure in Different Ethnic Groups and Relationship to the "White Coat Effect": A Cross-Sectional Study

BACKGROUND

Interarm differences (IADs) ≥10 mm Hg in systolic blood pressure (BP) are associated with greater incidence of cardiovascular disease. The effect of ethnicity and the white coat effect (WCE) on significant systolic IADs (ssIADs) are not well understood.

METHODS

Differences in BP by ethnicity for different methods of BP measurement were examined in 770 people (300 White British, 241 South Asian, 229 African-Caribbean). Repeated clinic measurements were obtained simultaneously in the right and left arm using 2 BPTru monitors and comparisons made between the first reading, mean of second and third and mean of second to sixth readings for patients with, and without known hypertension. All patients had ambulatory BP monitoring (ABPM). WCE was defined as systolic clinic BP ≥10 mm Hg higher than daytime ABPM.

RESULTS

No significant differences were seen in the prevalence of ssIAD between ethnicities whichever combinations of BP measurement were used and regardless of hypertensive status. ssIADs fell between the 1^st measurement (161, 22%), 2^nd/3^rd (113, 16%), and 2^nd–6^th (78, 11%) (1^st vs. 2^nd/3^rd and 2^nd–6^th, P < 0.001). Hypertensives with a WCE were more likely to have ssIADs on 1^st, (odds ratio [OR] 1.73 (95% confidence interval 1.04–2.86); 2^nd/3^rd, (OR 3.05 (1.68–5.53); and 2^nd–6^th measurements, (OR 2.58 (1.22–5.44). Nonhypertensive participants with a WCE were more likely to have a ssIAD on their first measurement (OR 3.82 (1.77 to −8.25) only.

CONCLUSIONS

ssIAD prevalence does not vary with ethnicity regardless of hypertensive status but is affected by the number of readings, suggesting the influence of WCE. Multiple readings should be used to confirm ssIADs.

A study of the VaSera arterial stiffness device in US patients

The cardio-ankle vascular index (CAVI) represents a promising index of arterial stiffness. However, neither the CAVI measure nor its measurement device, the VaSera, have undergone general testing in a North American clinical setting. To begin the process of collecting normal values in the United States, we studied 20 male and 28 female volunteers without reported cardiovascular or renal disease and no history of smoking. Their CAVIs, ankle-brachial indices (ABIs), and four-limb blood pressures were measured in three positions: supine, 7° Trendelenburg, and 7° reverse Trendelenburg. In addition, the ABI function was validated against an established ABI measurement technique. Position was found to affect CAVI and other hemodynamic parameters, indicating that CAVI is not robust to slight positional variations. No differences were found in the blood pressure between arms or legs (interbrachial or interankle), supporting recent findings from meta-analyses and studies but contradicting other work. This study represents an early step in bringing the VaSera device and its CAVI measurement into clinical practice.

Prevalence of systolic inter-arm differences in blood pressure for different primary care populations: systematic review and meta-analysis

BACKGROUND

Various prevalence figures have been reported for inter-arm differences in blood pressure (IAD); variation may be explained by differing population vascular risk and by measurement method.

AIM

To review the literature to derive robust estimates of IAD prevalence relevant to community populations.

DESIGN AND SETTING

Systematic review and meta-analysis.

METHOD

MEDLINE, Embase, and CINAHL were searched for cross-sectional studies likely to represent general or primary care populations, reporting prevalence of IAD and employing a simultaneous method of measurement. Using study-level data, pooled estimates of mean prevalence of systolic IADs were calculated and compared using a random effects model.

RESULTS

Eighty IAD studies were identified. Sixteen met inclusion criteria: pooled estimates of prevalence for systolic IAD ≥10 mmHg were 11.2% (95% confidence interval [CI] = 9.1 to 13.6) in hypertension, 7.4% (95% CI = 5.8 to 9.2) in diabetes, and 3.6% (95% CI = 2.3 to 5.0) for a general adult population (P<0.001 for subgroup differences). Differences persisted for higher cut-off values. Prevalences were lower for East Asian than for Western populations and were overestimated by sequential measurement where this could be compared with simultaneous measurement within studies (relative risk for IAD: 2.9 [95% CI = 2.1 to 4.1]). Studies with higher mean absolute systolic pressures had higher prevalences for a systolic IAD ≥10 mmHg (P = 0.04).

CONCLUSION

Prevalences of IADs rise in relation to underlying cardiovascular comorbidities of the population studied, and are overestimated threefold when sequential measurement is used. Population-specific variation in prevalences of IAD should be taken into account in delivering clinical care and in planning future studies.

Inter-arm blood pressure difference and mortality: a cohort study in an asymptomatic primary care population at elevated cardiovascular risk

BACKGROUND

Differences in blood pressure between arms are associated with increased cardiovascular mortality in cohorts with established vascular disease or substantially elevated cardiovascular risk.

AIM

To explore the association of inter-arm difference (IAD) with mortality in a community-dwelling cohort that is free of cardiovascular disease.

DESIGN AND SETTING

Cohort analysis of a randomised controlled trial in central Scotland, from April 1998 to October 2008.

METHOD

Volunteers from Lanarkshire, Glasgow, and Edinburgh, free of pre-existing vascular disease and with an ankle-brachial index ≤0.95, had systolic blood pressure measured in both arms at recruitment. Inter-arm blood pressure differences were calculated and examined for cross-sectional associations and differences in prospective survival. Outcome measures were cardiovascular events and all-cause mortality during mean follow-up of 8.2 years.

RESULTS

Based on a single pair of measurements, 60% of 3350 participants had a systolic IAD ≥5 mmHg and 38% ≥10 mmHg. An IAD ≥5 mmHg was associated with increased cardiovascular mortality (adjusted hazard ratio [HR] 1.91, 95% confidence interval [CI] = 1.19 to 3.07) and all-cause mortality (adjusted HR 1.44, 95% CI = 1.15 to 1.79). Within the subgroup of 764 participants who had hypertension, IADs of ≥5 mmHg or ≥10 mmHg were associated with both cardiovascular mortality (adjusted HR 2.63, 95% CI = 0.97 to 7.02, and adjusted HR 2.96, 95% CI = 1.27 to 6.88, respectively) and all-cause mortality (adjusted HR 1.67, 95% CI = 1.05 to 2.66, and adjusted HR 1.63, 95% CI = 1.06 to 2.50, respectively). IADs ≥15 mmHg were not associated with survival differences in this population.

CONCLUSION

Systolic IADs in blood pressure are associated with increased risk of cardiovascular events, including mortality, in a large cohort of people free of pre-existing vascular disease.

Prevalence of inter-arm blood pressure difference among clinical out-patients

OBJECTIVES

An increased inter-arm blood pressure difference is an easily determined physical finding, may use as an indicator of cardio vascular event and other sever diseases. Authors evaluated 477 patients to determine the prevalence and significance of inter-arm blood pressure difference.

METHODOLOGY

477 routine outdoor patients selected to observe the inter-arm blood pressure difference. Age, height, weight, body mass index, history of disease and blood pressure recorded.

RESULTS

The prevalence of ≥10 mmHg systolic inter-arm blood pressure difference was 5.0% was more as compared to 3.8% had diastolic inter-arm blood pressure difference. The prevalence of systolic and diastolic inter-arm difference between 6 to 10 mmHg was 31.4% and 27.9% respectively. Mean systolic inter-arm blood pressure difference was significantly higher among those patients had a multisystem disorder (10.57±0.98 mmHg) and followed by patients with cardiovascular disease (10.22±0.67 mmHg) as compared to healthy patients (2.71±0.96 mmHg). Various diseases highly influenced the increase in blood pressure irrespective of systolic or diastolic was confirmed strongly significant (p<0.001) at different inter arm blood pressure difference levels.

CONCLUSION

This study supports the view of inter-arm blood pressure difference as an alarming stage of increased disease risk that incorporated to investigate potential problems at an early diagnostic stage. A significant mean difference between left and right arm blood pressure recorded for many diseases.

The diagnostic value of supine blood pressure in hypertension

INTRODUCTION

Correct blood pressure (BP) measurement is crucial in the diagnosis of arterial hypertension (AH), and controversy exists whether supine BP should be treated as equal to sitting BP. The aim of this study was to evaluate the relation of supine BP to sitting BP and ambulatory BP with regard to identification of diagnostic cut-offs for hypertension.

MATERIAL AND METHODS

This study included 280 patients with AH (mean age: 44.3 ±10.6 years). The following measurements of BP were performed and analyzed: 1) sitting office blood pressure measurement (OSBP and ODBP); 2) supine BP (supSBP and supDBP), measured automatically (5 times with a 2-minute interval) during evaluation by the Niccomo device (Medis, Germany); 3) 24-hour ambulatory blood pressure (ABP) monitoring.

RESULTS

The mean supSBP and supDBP were found to be lower than OSBP and ODBP (130.9 ±14.2 vs. 136.6 ±15.5 mm Hg and 84.8 ±9.4 vs. 87.8 ±10.2 mm Hg, respectively; p < 0.000001). The correlations between ABP and supBP/OBP were moderate and strong (correlation coefficients in range 0.55-0.76). The ROC analysis revealed that mean supBP ≥ 130/80 mm Hg was more precise than OBP ≥ 140/90 mm Hg in diagnosing hypertension (AUC: 0.820 vs. 0.550; sensitivity 80.7% vs. 57.4%; specificity 83.2% vs. 52.7%; p < 0.0001) and the additive value derived mostly from its higher predictive power of identifying patients with increased night-time BP.

CONCLUSIONS

In young and middle-aged hypertensive patients the blood pressure during a 10-minute supine rest was lower than in the sitting position. The supine blood pressure ≥ 130/80 mm Hg was found to be a specific and sensitive threshold for hypertension.

Care trajectories are associated with quality improvement in the treatment of patients with uncontrolled type 2 diabetes: A registry based cohort study

AIMS

To analyse whether care trajectories (CT) were associated with increased prevalence of parenteral hypoglycemic treatment (PHT=insulin or GLP-1 analogues), statin therapy or RAAS-inhibition. Introduced in 2009 in Belgium, CTs target patients with type 2 diabetes mellitus (T2DM), in need for or with PHT.

METHODS

Retrospective study based on a registry with 97 general practitioners. The evolution in treatment since 2006 was compared between patients with vs. without a CT, using longitudinal logistic regression.

RESULTS

Comparing patients with (N=271) vs. without a CT (N=4424), we noted significant differences (p<0.05) in diabetes duration (10.1 vs. 7.3 years), HbA1c (7.5 vs. 6.9%), LDL-C (85 vs. 98mg/dl), microvascular complications (26 vs. 16%). Moreover, in 2006, parenteral treatment (OR 52.1), statins (OR 4.1) and RAAS-inhibition (OR 9.6) were significantly more prevalent (p<0.001). Between 2006 and 2011, the prevalence rose in both groups regarding all three treatments, but rose significantly faster (p<0.05) after 2009 in the CT-group.

CONCLUSIONS

Patients enrolled in a CT differ from other patients even before the start of this initiative with more intense hypoglycemic and cardiovascular treatment. Yet, they presented higher HbA1c-levels and more complications. Enrolment in a CT is associated with additional treatment intensification.

Developmental programming of cardiovascular disease following intrauterine growth restriction: findings utilising a rat model of maternal protein restriction

Over recent years, studies have demonstrated links between risk of cardiovascular disease in adulthood and adverse events that occurred very early in life during fetal development. The concept that there are embryonic and fetal adaptive responses to a sub-optimal intrauterine environment often brought about by poor maternal diet that result in permanent adverse consequences to life-long health is consistent with the definition of "programming". The purpose of this review is to provide an overview of the current knowledge of the effects of intrauterine growth restriction (IUGR) on long-term cardiac structure and function, with particular emphasis on the effects of maternal protein restriction. Much of our recent knowledge has been derived from animal models. We review the current literature of one of the most commonly used models of IUGR (maternal protein restriction in rats), in relation to birth weight and postnatal growth, blood pressure and cardiac structure and function. In doing so, we highlight the complexity of developmental programming, with regards to timing, degree of severity of the insult, genotype and the subsequent postnatal phenotype.

Long-term evolution of renal function in patients with type 2 diabetes mellitus: a registry-based retrospective cohort study

OBJECTIVES

To picture the 10-year evolution of renal function in patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) and to describe the risk factors for severe decline.

SETTING

Primary registration network with 97 general practitioners working in 55 practices sending routinely collected patient data.

PARTICIPANTS

From the database, we selected all patients aged 40 years or older with T2DM and at least two creatinine measurements in two different years with an interval of at least 3 months. Based on the last available value of estimated glomerular filtration rate calculated by the modification of diet in renal disease (MDRD) equation, patients were divided into grades of CKD. Severe decline (decline of >4 mL/min/year) and 'certain drop' (CD, year-to-year decline >10 mL/min) were determined in patients with CKD. Determinants of severe decline and CD were investigated with logistic regression and longitudinal logistic regression analysis, respectively.

PRIMARY OUTCOME MEASURE

Kidney function (MDRD).

RESULTS

4041 patients, 1980 women, were included. The mean age was 71 years, mean diabetes duration was 7.7 years; 1514 (38%) suffered from CKD, 231 (15%) presented with severe decline and 18% of the patients with CKD presented with two or more CDs. Younger age, male gender, mean glycated haemoglobin and a higher number of CDs were significantly associated with the presence of severe decline (p<0.05); statins and higher diastolic blood pressure were significantly associated with the absence of severe decline (p<0.001). ACE inhibitors, other antihypertensive drugs and antidiabetic drugs including insulin therapy were specific determinants of CD.

CONCLUSIONS

CKD is highly prevalent in patients with T2DM; a minority of patients evolve into severe decline that is associated with younger age, male gender, 'CD' and manageable factors such as blood pressure, blood glucose, associated drugs prescriptions and statin therapy. Further prospective observational and experimental research is needed to clarify the nature of those associations.