Ambulatory blood pressure monitoring is a useful clinical tool in nephrology

Strategies to prevent, diagnose and treat kidney disease related to systemic arterial hypertension: a narrative review from the Mexican Group of Experts on Arterial Hypertension

This narrative review highlights strategies proposed by the Mexican Group of Experts on Arterial Hypertension endorsed to prevent, diagnose, and treat chronic kidney disease (CKD) related to systemic arterial hypertension (SAH). Given the growing prevalence of CKD in Mexico and Latin America caused by SAH, there is a need for context-specific approaches to address the effects of SAH, given the diverse population and unique challenges faced by the region. This narrative review provides clinical strategies for healthcare providers on preventing, diagnosing, and treating kidney disease related to SAH, focusing on primary prevention, early detection, evidence-based diagnostic approaches, and selecting pharmacological treatments. Key-strategies are focused on six fundamental areas: 1) Strategies to mitigate kidney disease in SAH, 2) early detection of CKD in SAH, 3) diagnosis and monitoring of SAH, 4) blood pressure targets in patients living with CKD, 5) hypertensive treatment in patients with CKD and 6) diuretics and Non-Steroidal Mineralocorticoid Receptor Inhibitors in Patients with CKD. This review aims to provide relevant strategies for the Mexican and Latin American clinical context, highlight the importance of a multidisciplinary approach to managing SAH, and the role of community-based programs in improving the quality of life for affected individuals. This position paper seeks to contribute to reducing the burden of SAH-related CKD and its complications in Mexico and Latin America.

Fluid Status, Blood Pressure, and Cardiovascular Abnormalities in Patients on Peritoneal Dialysis

♦ Objective

Hypertension, reduced arterial distensibility, and left ventricular hypertrophy (LVH) are risk factors for mortality in hemodialysis patients. However, few studies have focused on the relation between fluid status, blood pressure (BP), and cardiovascular abnormalities in peritoneal dialysis (PD) patients. This study was designed, first, to assess, using tracer dilution techniques, fluid status in PD patients compared to a control population of stable renal transplant (RTx) patients; second, to study the relation between fluid status, BP, and arterial wall abnormalities; third, to assess the determinants of cardiac structure; and last, to compare office and ambulatory BP measurements with respect to cardiac abnormalities.

♦ Design

Cross-sectional study.

♦ Setting

Multicenter study.

♦ Patients

41 stable PD patients with a mean Kt/V urea of 2.4 ± 0.7, and 77 stable RTx patients.

♦ Intervention

Fluid status was assessed by tracer dilution techniques: extracellular volume (ECV) with bromide dilution; total body water (TBW) with deuterium oxide; and plasma volume (PV) with dextran 70. Echocardiography was performed to assess left ventricular mass (LVM), left ventricular end diastolic diameter (LVEDD), and relative wall thickness as indicators of LVH. Echography of the common carotid artery was performed to assess arterial distensibility. Both office and 24-hour ambulatory BP measurements were performed.

♦ Results

Fluid status, as assessed by ECV corrected for body surface area (BSA) (ECV:BSA), was significantly different between PD and RTx patients (9.4 ± 2.6 vs 8.6 ± 1.2 L/m2, p < 0.05). In 36.6% of the PD patients, ECV:BSA was above the 90th percentile of the RTx patients. Fluid status corrected for BSA, assessed by TBW (TBW:BSA), ECV (ECV:BSA), or plasma volume (PV:BSA), was significantly related to diastolic BP (DBP) ( r = 0.35, r = 0.37, r = 0.53; p < 0.05). Arterial distensibility of the common carotid artery was related to systolic BP (SBP) ( r = –0.36, p < 0.05). ECV was significantly related to LVEDD ( r = 0.41, p < 0.05) as a marker of eccentric LVH, whereas arterial distensibility was related to relative wall thickness ( r = –0.53, p < 0.001) as a marker of concentric LVH. An abnormal day–night BP rhythm, which was not related to fluid status, was observed in 68.4% of patients. Ambulatory DBP and SBP but not office DBP and SBP were related to LVM ( r = 0.43, r = 0.46; p < 0.01).

♦ Conclusions

A large proportion of PD patients whose treatment prescriptions are in accordance with the Dialysis Outcomes Quality Initiative guidelines were found to be overhydrated compared with a population of stable RTx patients. Fluid status was significantly related to DBP and eccentric LVH, whereas arterial distensibility of the common carotid artery was significantly related to SBP and concentric LVH. In contrast to ambulatory BP, office BP was not related to LVM.

Two-Day ABPM-Derived Indices and Mortality in Hemodialysis Patients

BACKGROUND

Blood pressure (BP) and arterial stiffness are known cardiovascular risk factors in hemodialysis (HD) patients. This study examines the prognostic significance of 44-hour BP circadian rhythm and ambulatory arterial stiffness index (AASI) in this population.

METHODS

A total of 80 HD patients underwent 44-hour ambulatory BP monitoring (ABPM) with a TM-2430 monitor during a standard midweek interdialytic interval and followed up for 4.5 ± 1.7 years. The end point was all-cause mortality.

RESULTS

About 76% of participants were hypertensive (40% uncontrolled), 62% were nondippers, and 23% risers during the first interdialytic day, whereas 73% and 44% in the second day, respectively. During follow-up, 31 patients (40%) died. These showed higher pulse pressure (PP) and AASI44 and AASI of the second interdialytic period. The incidence of all-cause mortality was higher in HD patients with AASI44 > median, i.e. >0.54 (interquartile range = 14) (54% vs. 28%, χ 2 = 5.3, P = 0.021) when compared with those with lower AASI44. Second, but not first-day ABPM-derived parameters, namely nondipping (log-rank χ 2 = 6.10, P = 0.0134) or reverse dipping status (log-rank χ 2 = 5.32, P = 0.210) and arterial stiffness index (log-rank χ 2 = 6.61, P = 0.0101) were significantly related to greater mortality.

CONCLUSIONS

These findings indicate a strong relationship between arterial stiffness and cardiovascular risk and support a wider use of 44-hour ABPM recording for risk stratification in HD patients.

The Optimal Blood Pressure Target in Different Dialysis Populations

Hypertension is common and contributes to adverse outcomes in patients undergoing dialysis. However, the proper blood pressure (BP) target remains controversial and several factors make this difficult. This study aimed to investigate the adequate BP target in patients undergoing prevalent dialysis. Data were retrieved from the Clinical Research Center for End-Stage Renal Disease (2009–2014). 2,299 patients undergoing dialysis were evaluated. Patients were assigned into eight groups according to predialysis systolic blood pressure (SBP). The primary outcome was all-cause mortality. During the median follow-up of 4.5 years, a U-shape relation between SBP and mortality was found. The risk of mortality was increased in the SBP <110 and ≥170 mmHg groups. In subgroup analysis, the risk of mortality was similarly shown U-shape with SBP in subjects with no comorbidities, and no use of antihypertensive agents. However, only lowest SBP was a risk factor for mortality in patients with older, having diabetes or coronary artery disease, whereas highest SBP was an only risk factor in younger patients. In respect of dialysis characteristics, patients undergoing hemodialysis showed U-shape between SBP and mortality, while patients undergoing peritoneal dialysis did not. Among hemodialysis patients, patients with shorter dialysis vintage and less interdialytic weight gain showed U-shape association between SBP and mortality. This study showed that the lowest or highest SBP group had higher risk of mortality. Nevertheless, the optimal target BP should be applied according to individual condition of each patient.

The influence of time point of blood pressure measurement on the outcome in hemodialysis patients

The blood pressure (BP) behaviors of hemodialysis (HD) population presented a unique pattern much different from that of the general population. This pattern is composed of chronic BP burden over interdialytic period and acute BP fluctuation during dialysis sessions. Peridialysis, interdialysis, and intradialysis are three routinely used time points to capture this complex BP behavior. However, BP at each time point was measured in various forms and conveyed different prognostic information. The measurement and interpretation of the tide-like BP behavior in HD population posed great challenge. In this review, we focused on the prognostic information of the BP behavior at each time point in HD patients and further discussed the optimal measurement of this unique BP behavior to best capture the BP-outcome association.

Peripheral artery disease and blood pressure profile abnormalities in hemodialysis patients

BACKGROUND

Patients undergoing chronic hemodialysis (HD) are at increased risk for peripheral artery disease (PAD). Both ankle-brachial index (ABI) and ambulatory blood pressure monitoring (ABPM) in the interdialytic period have been shown to be strong predictors of all-cause mortality.

METHODS

This cross-sectional study investigated the relationship between ABPM profile and ABI in 81 HD patients. ABPM was measured throughout a 44-h midweek interdialytic period. Pre-dialysis ABI was evaluated with a BOSO ABI device. An ABI value <0.9 or ≥1.3 was defined as abnormal.

RESULTS

In the whole study group (72 % males, mean age 67 ± 14 years), there was an increase in BP (p < 0.05) and in systolic BP night/day ratio (n/dSR, p = 0.01) during the interdialytic period. Patients with abnormal ABI (n = 29) more frequently had a positive history for cerebrovascular accident and PAD and higher proBNP values than those with normal ABI (n = 52). No difference was detected among ABPM-derived components except for the n/dSR (p = 0.02). Patients with abnormal ABI showed a significantly increased n/dSR (p = 0.02) and ambulatory arterial stiffness index (AASI) (p = 0.006) on the second day compared to the first. Patients with n/dSR >1 during day 2 (n = 34) were older, showed significantly higher proBNP and AASI and were more likely to reveal abnormal ABI compared to those with a lower n/dSR (p = 0.006).

CONCLUSIONS

Abnormal ABI in HD patients is associated to changes in interdialytic ABPM pattern, namely higher n/dSR on day 2. These data may indicate the pathophysiological mechanisms underlying the worse outcome observed in HD patients.

Assessment and management of hypertension in patients on dialysis

Hypertension is common, difficult to diagnose, and poorly controlled among patients with ESRD. However, controversy surrounds the diagnosis and treatment of hypertension. Here, we describe the diagnosis, epidemiology, and management of hypertension in dialysis patients, and examine the data sparking debate over appropriate methods for diagnosing and treating hypertension. Furthermore, we consider the issues uniquely related to hypertension in pediatric dialysis patients. Future clinical trials designed to clarify the controversial results discussed here should lead to the implementation of diagnostic and therapeutic techniques that improve long-term cardiovascular outcomes in patients with ESRD.

Ambulatory blood pressure monitoring in kidney transplant patients: RETENAL study

Hypertension is common following renal transplantation, affecting up to 80% of transplant recipients. It is generally accepted that hypertension is associated with poor graft survival and reduced life expectancy, contributing to increased cardiovascular risk factors and mortality rates. The aim of the study was to compare the blood pressure (BP) control in kidney transplant patients through the use of ambulatory BP monitoring (ABMP) versus office BP measurements (oBP). A multicenter, cross-sectional, observational study was conducted in 30 nephrology/kidney transplant units. Eligible patients included hypertensive cadaveric kidney transplant recipients aged <70 years, with a functioning kidney for at least 1 year and with an estimated glomerular filtration ≥30 mL/min/1.73 m(2) and a serum creatinine < 2.5 mg/dL. Recorded data included demographic characteristics, oBP, and ABPM and labroatory investigations. The 868 patients showed a mean recipient age of was 53.2 ± 11.6 years and mean follow-up after transplantation, 5.5 ± 2.8 years. Mean systolic and diastolic oBP were 140.2 ± 18 and 80.4 ± 10 mm Hg, respectively. Seventy-six percent of patients had oBP higher than or equal to 130/80 mm Hg. Mean 24 hour ABPM were 131.5 ± 14 and 77.4 ± 8.7 mm Hg for systolic and diastolic BP, respectively. Using the ABPM, we observed that 36.5% of subjects were controlled (mean 24-hour BP < 130/85 mm Hg). The two methods (oBP and ABPM) showed significant agreement. After ABPM, 65% of patients diagnosed as true controlled hypertension were considered to have white-coat RH. In clinical practice ABPM may help for better adjustment of drugs for adequate BP control.

Twenty-four-hour ambulatory blood pressure monitoring in infants and toddlers

During the past several years, 24-hour (24-h) ambulatory blood pressure monitoring (ABPM) has become a useful tool for the diagnosis and management of children and adolescents with elevated blood pressure (BP). Some reports have also provided blood pressure nomograms for particular devices. However, there are very few reports of the use of this method in very young children. In our study we investigated the applicability of ABPM in 97 healthy infants and toddlers, aged from 2 to 30 months. A satisfactory ABPM profile was obtained in 86.6% of the children, with an average of 75.0% satisfactory BP recordings. The mean +/- SD systolic and diastolic BP of healthy infants and toddlers was 99+/-12/62+/-12 mmHg during the daytime and 95+/-11/57+/-10 mmHg during the night, with no gender difference being observed. The 24-h mean +/- SD systolic and diastolic BP, which may be a more appropriate measure of BP in this particular age group, was found to be 97+/-12/59+/-11 mmHg. We also confirmed the increase in systolic and diastolic BP with increased height (length). There was only a slight nocturnal decrease in BP. We conclude that this method is applicable for the assessment of blood pressure in very young children.

Special Article: Improving Outcomes in CKD and ESRD Patients: Carrying the Torch from Training to Practice

Practicing nephrologists are spending more time caring for end-stage renal disease (ESRD) and chronic kidney disease (CKD) patients. Despite this focus, and considerable advances in the understanding of those aspects of care that impact on clinical outcomes, morbidity, mortality, and quality of life for these patients has not improved substantially over the past decade. One of the possible explanations for this lack of progress is the structure of current nephrology training programs, where ESRD and CKD patient care is not emphasized. To address this issue, we developed a short preceptorship for second-year nephrology fellows, including didactic lectures and workshops. Of 67 participating fellows, 50% were from programs offering 3 or fewer months of exposure to outpatient hemodialysis, and 25% reported no exposure to peritoneal dialysis. Of more concern, 25% reported no "official rounds" with an attending nephrologist on dialysis patients. If nephrologists are to take their appropriate place as leaders of the care delivery team, nephrology fellowships must be restructured with appropriate emphasis placed on the comprehensive care of ESRD and CKD patients.

Ambulatory blood pressure monitoring in renal transplant patients: modifiable parameters after active antihypertensive treatment

BACKGROUND

Hypertension (HT) accounts for nearly 60% to 80% of renal transplant patients (RT). It is one of the most important risk factors for cardiovascular diseases and may cause chronic graft dysfunction. Therefore, it is important to accurately detect and treat HT. We aimed to evaluate the changes in ambulatory blood pressure monitoring (ABPM) parameters among hypertensive RT after active treatment compared with baseline values.

METHODS

Thirty seven RT (25 men, 12 women, aged 49.4 +/- 11.2 year) diagnosed with mild to moderate HT underwent 24-hour ABPM after a 4-week washout period (W0). For the 23 RT with confirmed HT of a second 24-hour ABPM was recorded after 4 weeks of treatment with doxazosin GITS (-4 mg once daily in the morning), a new formulation of an alpha1-receptor inhibitor (W4). Nondippers were considered when mean blood pressure (BP) showed a < or = 10% reduction during sleep. Statistical analyses included Saphiro-Wilks test, Student t test, and ANOVA.

RESULTS

After active treatment systolic, diastolic, and mean BP (SBP, DBP, MBP) significantly decreased during diurnal and 24 hours but not the nocturnal period. No significant change was observed for heart rate nor for pulse pressure during any period. The prevalence dippers increased from 0% to 17% after treatment. After placebo administration 8 among 37 RT with HT diagnosed according to casual BP remained hypertensive at nighttime (but not at daytime) according to 24-hour ABPM.

CONCLUSIONS

Diurnal and 24-hour periods of ABPM showed significant changes in SBP, DBP, and MBP after active treatment with doxazosin GITS. No significant BP changes were observed in the nocturnal period or in dipper status. Further studies using ABPM must be undertaken to determine the optimal dosage and time of administration of antihypertensive drugs in RT.

Blood pressure measurement in dialysis patients

The best method and timing of blood pressure (BP) measurement in end-stage renal disease are subject to controversy. This issue is especially relevant in hemodialysis patients, where unique causes of inaccuracy may exist. The lack of standardization of BP measurement in the dialysis unit may lead to misdiagnosis, so close attention must be paid to technical methods to obtain BP. A composite of BP measurements over a period of 1 to 2 weeks rather than isolated readings should be used for guidance. Interdialytic BP monitoring with an ambulatory BP monitor is the most reproducible method and is thought to best represent BP in dialysis patients. If available, ambulatory BP is a useful tool to evaluate the quality of BP control in the interdialytic period. Alternative forms of BP measurement, such as home BP, 20-minute postdialysis BP, and short (3-hour to 4-hour) ambulatory blood pressure monitoring (ABPM), could prove useful when feasible or available. In this paper, we discuss the evidence regarding BP measurement in dialysis patients, new techniques under development, and recommendations for clinical practice.

Ambulatory blood pressure monitoring in renal transplantation: should ABPM be routinely performed in renal transplant patients?

In renal transplant recipients, hypertension is common and associated with increased cardiovascular and allograft rejection risks. Ambulatory blood pressure monitoring is required for its accurate diagnosis and adequate treatment, as it clearly offers several advantages over office or casual blood pressure measurements. First, it correlates better with target-organ damage and with cardiovascular mortality. Second, ambulatory blood pressure monitoring can eliminate "white coat" hypertension. Most important is the identification of nocturnal hypertension, an independent cardiovascular risk factor. A circadian nondipping pattern is often found in renal transplant recipients, most probably resulting from cyclosporine A and persistent fluid overload in the early posttransplant phase (approximately 70% prevalence), but reflecting an underlying renal (parenchymal or vascular) allograft disease when persistent (approximately 25% prevalence) beyond the first year posttransplant.

Efficacy and safety of doxazosin GITS in hypertensive renal transplant patients: comparison of 8 and 4 mg

BACKGROUND

Hypertension (HT), a prevalent complication in renal transplant patient (RT), must be accurately treated because cardiovascular disease is the leading cause of death and of chronic graft dysfunction. Sympathetic activity may contribute to HT in RT, yielding the rationale to suspect that doxazosin, an alpha1-adrenergic receptor inhibitor, may lower blood pressure (BP). The aim of this study was to evaluate the efficacy and safety of doxazosin GITS (4 and 8 mg) in RT.

METHODS

Twenty-three hypertensive RT received doxazosin 4 mg once daily for 4 weeks (W4) followed by a 4-week washout (W0) and 17/23 treated with doxazosin 8 mg for 4 more weeks (W8) due to persistent HT. All patients underwent 24-hour ambulatory blood pressure monitoring (ABPM) after W0, W4, and W8. Laboratory tests were performed, adverse events recorded, and prostatic symptomatology examined. Statistical analysis included Saphiro-Wilks, Student t, ANOVA, Wilcoxon, or Friedman tests.

RESULTS

The systolic, diastolic, and mean BP were significantly lowered at W4 in awake (P<.001) and 24 hour period (P<.005) but not sleep recordings. Doxazosin 8 mg had no significant additional effect to lower BP at any period. Normotension was reached in 13% and 21.7% of patients at W4 and W8, respectively. Palpitations were the only reported adverse event after treatment (incidence similar to placebo). There was no significant change in the laboratory values.

CONCLUSIONS

Doxazosin (-4 mg) effectively decreased BP in awake and 24-hour periods without a significant improvement during sleep. A double dose of the drug added little benefit. Optimal BP was reached by an insufficient number of patients. Doxazosin proved to have a good tolerance and safe profile. This results suggest that doxazosin should be considered a good add-on treatment to other antihypertensive drugs in RT.

Outcome studies in diabetic nephropathy

Outcome studies in diabetic nephropathy have focused on strategies to prevent progression of diabetic nephropathy, the leading cause of ESRD in the United States. Once diabetics develop overt nephropathy, prognosis is poor. Risk factors for diabetic nephropathy are discussed, and include hyperglycemia, hypertension, angiotensin II, proteinuria, dyslipidemia, smoking, and anemia. Major outcomes as well as outcome studies in diabetic nephropathy for patients with microalbuminuria and macroalbuminuria are reviewed. Furthermore, the role of therapy with angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, calcium channel blockers, and mineralocorticoid receptor antagonists as well as selected combination therapy are discussed. Recommendations for therapy with ace inhibitors and angiotensin II receptor blockers are made based on this evidence.

Cardiovascular effects of successful renal transplantation: a 1-year sequential study of left ventricular morphology and function, and 24-hour blood pressure profile

BACKGROUND

Cardiovascular disease is the leading cause of death in renal transplant recipients. The purpose of this study was to determine the effects of a successful renal transplantation on left ventricular morphology and function and on the 24-hr blood pressure profile.

METHODS

Twenty-four patients with end-stage renal disease were prospectively studied by ambulatory blood pressure monitoring and echocardiography before and at 3, 6, and 12 months after renal transplantation. Patients were also analyzed according to their renal function after transplantation.

RESULTS

We observed a significant drop in the mean values of daytime and nocturnal systolic blood pressure and in the 24-hr systolic pressure load at 12 months after transplantation. The most frequent echocardiographic finding was left ventricular hypertrophy (LVH), for which the incidence decreased from 75% before transplantation to 52.1% at 12 months after transplantation (P = 0.125). There was a significant decrease in left ventricular dilatation, and systolic dysfunction normalized in all patients after 12 months. The variables that best independently predicted the decrease in LVH were serum creatinine levels and the 24-hr systolic pressure load as registered by ambulatory blood pressure monitoring at 12 months after transplantation. We observed significant decreases in left ventricular mass and left ventricular mass index in the group of patients who had adequate renal function, as compared with no changes in patients who did not.

CONCLUSIONS

Correction of the uremic state by renal transplantation leads to complete resolution of systolic dysfunction, regression of LVH, and improvement of left ventricular dilatation. In fact the reduction of LVH was dependent on adequate renal function and on a decrease in the systolic pressure levels.

Ambulatory blood pressure monitoring in children and adolescents

With recent technological advances, 24-hour ambulatory blood pressure (BP) monitoring (ABPM) has become a useful tool for the evaluation, diagnosis, and management of hypertensive children. It provides a more accurate representation of an individual's BP rather than intermittent casual or office BP measurements. Hence, ABPM is being used more often to assess the BP of children. In this comprehensive review, we provide the reader with the available literature on ABPM, discuss the advantages and limitations of ABPM, and the interpretation of ABPM data. The role of ABPM in various clinical conditions and hypertension research in children is presented.

Ambulatory blood pressure monitoring in chronic renal disease: technical aspects and clinical relevance

PURPOSE OF REVIEW

To evaluate the current value of ambulatory blood pressure monitoring in patients with chronic renal disease and end-stage renal disease.

RECENT FINDINGS

Ambulatory blood pressure monitoring has become an important tool in hypertension research and clinical practice. Its use in essential hypertension shows a strong predictive ability in the assessment of cardiovascular outcomes. In chronic renal failure and end-stage renal disease, the role of ambulatory blood pressure monitoring is still being actively evaluated, and available evidence shows that it is better than office blood pressure in predicting left ventricular hypertrophy and progression of renal dysfunction in patients with chronic renal failure. In end-stage renal disease, preliminary data suggest better prediction of mortality in hemodialysis patients in comparison with clinic blood pressures. The most conspicuous problems with the literature on this subject are small sample sizes and the paucity of longitudinal observational studies and intervention trials.

SUMMARY

Preliminary data and extrapolations from essential hypertension have justified a growing excitement about the use of ambulatory blood pressure monitoring in renal disease. However, further research will have to address the limitations of the available literature before generalization of its use is implemented.

Self-measured systolic blood pressure in the morning is a strong indicator of decline of renal function in hypertensive patients with non-diabetic chronic renal insufficiency

While blood pressure is a recognized major determinant of renal function deterioration, the role of self blood pressure measurement (BPM) in predicting the loss of renal function in hypertensive patients with chronic renal insufficiency (CRI) has not been adequately addressed. One hundred and thirteen patients (F/M: 46/67; 56 +/- 1 years) with CRI (mean serum creatinine: 1.87 +/- 0.08; range: 1.4 to 3.5 mg/dl; average urinary protein excretion: 1.2 +/- 0.2 g/24 hrs.) were followed for 3 years. The record of renal biopsy revealed that 74 patients had IgA nephropathy, 16 had chronic glomerulonephritis, and 6 had membranous nephropathy, while 17, unbiopsied patients had underlying renal disease of unknown origin. Self BPM were made at regular intervals throughout the course of the study. All recorded blood pressures were included in a stepwise multiple regression analysis in which the decline in GFR per year was the dependent variable. Patients were primarily treated with a combination of amlodipine (5 to 20 mg daily), a calcium antagonist, and benazepril (2.5 to 5 mg daily), an ACE inhibitor in an effort to reduce their blood pressure at the office to < 130/85 mmHg. The simple correlation between blood pressures (i.e., office, home morning and home evening) and the decline in GFR were all statistically significant. The correlation coefficients of determination for this model were as follows: r = 0.64 for home morning SBP; 0.43 for office SBP; 0.39 for office DBP; and 0.38 for home morning DBP. The level of urinary protein excretion did not correlate with the decline in GFR. These data suggest that self BPM improves prognostic ability in hypertensive patients with CRI.

Long-term control of hypertension in dialysis patients by low dose atenolol

Hypertension in dialysis patients is considered a major factor in cardiovascular mortality. We investigated long-term efficacy of intermittent atenolol (AT) administration in 10 (7M/3F) hypertensive dialysis patients, age 60.5 (38-72), on dialysis for 56.5 months (8-156) thrice per week (10.5-13.5 h/w) (A). A similar group of 11 normotensive patients served as controls (B). Hypertension was defined as BP> 140/90 (day) and >120/80 mmHg (night) by a 44-h ambulatory BP monitoring (ABPM) after the mid-week session. Dialysis ultrafiltration, hematology, biochemistry were similar in A and B. Atenolol was started on an alternate day, 37.5 mg/w and increased as needed. After 34 days (6-80) and a dose of 68.75 (37.5-450) mg/w, BP dropped (ABPM: MAP 104+/-11.5 to 95.6+/-10.4 mmHg, P=0.0025) similar to controls and daytime HR dropped: 84.6+/-9.2 to 69.3+/-8.2, P=0.0008 and at night: 79.5+/-7.6 to 68.6+/-8.6 b/1' becoming lower than in B: 83+/-10.8/69.3+/-8.2, P=0.009 and 80.5+/-11.7/68.6+/-8.6 b/1' (P=0. 02). Six months later ABPM in A as well as echocardiography in A and B remained unchanged. Moderate, volume independent hypertension in stable dialysis patients is easily controlled during the interdialytic period by small intermittent atenolol doses.

Blood pressure reduction in the morning yields beneficial effects on progression of chronic renal insufficiency with regression of left ventricular hypertrophy

Self-monitoring values of blood pressure may better reflect the average long-term blood pressure value than sporadic measurements in the physician's office and be more useful for blood pressure control. In the present study, we compared the results of self-monitoring of blood pressure values, especially in the morning, with office blood pressure, and related these to progression of chronic renal insufficiency and left ventricular hypertrophy (LVH). Thirty-four patients were selected from 316 subjects with chronic renal insufficiency (average serum creatinine 1.72 +/- 0.15 mg/dl, mean age 52.6 +/- 3.5 yrs) in accordance with the following criteria (1) office blood pressure was less than 140/90 mmHg, (2) blood pressure was controlled with amlodipine (5-20 mg/day) combined with benazepril (2.5 mg/day), (3) morning blood pressure was greater than 150/90 mmHg at 6-9 AM and (4) LVH had been determined by echocardiography (posterior wall thickness; PWT > or = 12 mm). The patients were assigned to 2 groups at random and were given: (1) guanabenz (GB; 2-8 mg at I I PM, n = 17) or (2) placebo (n = 17). Two years later, the average blood pressure of both groups as measured in the office was not significantly different: however, BP in the morning was significantly reduced from 158 +/- 6 to 134 +/- 4 mmHg in GB treated group (P< 0.001). In 14 of 17 patients in GB treated group, LVH resolved and there was only mild progression of nephropathy (serum creatinine: 1.69 +/- 0.18 to 1.81 +/- 0.19 mg/dl). In 12 of 14 patients in placebo group, whose morning blood pressure remained at greater than 150/90 mmHg, LVH was retained and there was moderate progression of nephropathy (serum creatinine: 1.73 +/- 0.14 to 2.62 +/- 0.50mg/dl). From these results, it is suggested that antihypertensive treatment with combination therapy based on self-monitoring BP is cardio-renoprotective in patients with chronic renal insufficiency and LVH.

Reproducibility of ambulatory blood pressure monitoring in hemodialysis patients

Ambulatory blood pressure monitoring (ABPM) has been increasingly used in hemodialysis (HD) practice and research; however, no study has evaluated the reproducibility of ABPM in this population. To address this question, we performed 48-hour interdialytic ABPM on 21 HD patients (mean age, 53 +/- 16 years; 7 women) on two different occasions 68 +/- 34 days (range, 30 to 154 days) apart. To qualify for the protocol, patients had to be at the same dry weight and on the same vasoactive drug regimen at both monitoring periods. BP was analyzed according to three different methods: isolated pre-HD and post-HD values, average pre-HD and post-HD values for the five HD sessions surrounding each monitoring period, and 48-hour interdialytic ABPM. Reproducibility was determined by analysis of the SD of the differences (SDD) between the two monitoring periods and the coefficient of variation of each method of BP determination. Our results show better reproducibility of ABPM (SDD, 10.6/6.6 mm Hg; coefficient of variation, 7.5%/8.1%) compared with isolated pre-HD BP (SDD, 24.4/11.3 mm Hg; coefficient of variation, 16.7%/14.1%) or post-HD BP (SDD, 16.8/14.5 mm Hg; coefficient of variation, 11.7%/17.8%), and averaged pre-HD BP (SDD, 14.7/7.2 mm Hg; coefficient of variation, 10.1%/9.1%) or post-HD BP (SDD, 12.4/8.7 mm Hg; coefficient of variation, 8.9%/11.1%). The reproducibility of the decrease in BP during sleep was poor, with up to 43% of the subjects changing dipping category within or between interdialytic periods. We conclude that ABPM is the most accurate method to study BP in HD patients over time. However, variability is significant, and there is poor reproducibility of the nocturnal decline in BP.

Ambulatory blood pressure monitoring in potential renal transplant donors

BACKGROUND

Hypertension is considered to be a contraindication in potential renal transplant donors. Ambulatory blood pressure monitoring (ABPM) was developed as an alternative to in-office blood pressure measurement (OBPM). The aim of this study was to determine the sensitivity of ABPM in revealing hypertension in potential renal transplant donors, and to measure the correlation between ABPM results and target organ damage.

METHODS

The study included 126 potential living-related renal transplant donors. The potential donors's blood pressures were measured during three separate clinic visits and then evaluated using 24-h ABPM. Cardiac and ophthalmological examinations were also performed to investigate target organ damage in all of the donors.

RESULTS

According to the OBPM, 89 potential donors were normotensive and 37 had borderline or mild hypertension. Of the normotensive group, six were diagnosed as hypertensive after 24-h ABPM, and these subjects had target organ involvement. The status of the other 83 donors remained unchanged after ABPM and investigation for target organ damage. Thirteen of the 37 subjects who had borderline or mildly elevated pressures on OBPM were classified as normotensive after ABPM. These 13 individuals exhibited no hypertension-related target organ damage. The other 24 patients who had been classified as borderline or mildly hypertensive on OBPM fulfilled the criteria for hypertension after ABPM, and hypertensive changes were found at target organ evaluation. Before donor nephrectomy, 94 subjects who were classified as normotensive prior to transplantation underwent renal angiography for routine pretransplant evaluation, and none showed hypertensive or atherosclerotic changes.

CONCLUSION

In our study, ABPM was found to be more sensitive than OBPM in terms of identifying hypertension in potential renal transplant donors.

Prediction of left ventricular geometry by clinic, pre-dialysis and 24-h ambulatory BP monitoring in hemodialysis patients: CREED investigators

OBJECTIVE

Arterial hypertension is an established risk factor for left ventricular hypertrophy (LVH) in the uremic population. However, whether 24-h monitoring is a better predictor of LVH than clinic blood pressure and routine pre-dialysis measurements in these patients is still undefined.

METHODS

This problem was studied in 64 nondiabetic hemodialysis patients without heart failure. The echocardiographic study as well as the clinic and 24-h ambulatory blood pressure (BP) measurements were performed during the day off-dialysis. Pre-dialysis arterial pressure was calculated as the average value of the 12 routine recordings taken during the month preceding the study.

RESULTS

In multivariate models, including also sex, body mass index, hematocrit and serum cholesterol, pre-dialysis systolic, diastolic and pulse pressures were the only independent BP determinants of heart geometry. Twenty-four hour ambulatory BP monitoring (ABPM) did add significant (but weak) information to the prediction of left ventricular internal dimension, i.e. it increased by 9% (P = 0.01) the variance already explained by pre-dialysis diastolic BP and other significant covariates. However, 24-h ABPM did not add any significant and independent explanatory information to the corresponding pre-dialysis measurements for the posterior wall and interventricular septum measurements, and for left ventricular mass (-0.6 to +3.9%; average +1.1%).

CONCLUSIONS

In dialysis patients, pre-dialysis BP is at least as strong a predictor of left ventricular mass as 24-h ambulatory monitoring. Thus, the average of 12 routine pre-dialysis measurements may be used to predict heart geometry in dialysis patients without any loss of information in comparison with 24-h ambulatory monitoring.

What is hypertension in chronic haemodialysis? The role of interdialytic blood pressure monitoring

BACKGROUND

Hypertension in chronic haemodialysis patients contributes significantly to morbidity and mortality. Treatment decisions are usually based on predialysis readings, which may not accurately reflect control during the interdialytic period.

METHODS

We studied 40 randomly selected subjects on haemodialysis and compared readings by different methods at set times during the dialysis session with the 48-h interdialytic ambulatory readings. Conventional sphygmomanometer, automated Dinamap and Tm 2421(A&D) ambulatory monitor were used for BP measurements.

RESULTS

Conventional sphygmomanometry and self measured automatic readings (Dinamap) were highly correlated (systolic r=0.93, P<0.001; diastolic r=0.90, P<0.001). Mean blood pressure on arrival ((PreC(0)) 158 mmHg systolic, 80 mmHg diastolic and 106 mmHg mean) significantly overestimated the mean ambulatory reading during the 6 h prior to attendance ((preAm(6h)) systolic 147 (P<0.01), diastolic 75 (P<0.01), mean 99 (P<0.01)). Fifteen patients (41%) demonstrated a marked difference (>20/10 mmHg) between the PreC(0) and preAm(6h) (white-coat effect) persisting in seven patients (19%) after a period of rest 10 min predialysis (preC(10)) and present even in self-recorded Dinamap readings. There was a significant negative relationship between the systolic rise and the number of months on dialysis (P<0.05). Mean ambulatory BP on interdialytic day 2 was significantly greater than on day 1 whereas the awake-sleep differences were less on day 2 than day 1, both perhaps reflecting differences in volume status. The 20 min post-dialysis measurement (PoC(20)) for systolic, diastolic, and mean, unlike predialysis (PreC(0) and preC(10)), onset (onC) and end of dialysis readings (enC) did not differ significantly from 48 h interdialytic means.

CONCLUSIONS

The best representation of interdialytic pressure was the 20-min post-dialysis reading. Walk-in predialysis pressures overestimate mean interdialytic pressures due to a high incidence of white-coat effect, which shows some habituation with time on dialysis. Ambulatory monitoring has a role in evaluating persistent poor blood pressure control in haemodialysis patients.