Gert A. van Montfrans

Stent Placement in Patients With Atherosclerotic Renal Artery Stenosis and Impaired Renal Function A Randomized Trial

BACKGROUND: Little is known about the efficacy and safety of renal artery stenting in patients with atherosclerotic renal artery stenosis (ARAS) and impaired renal function. OBJECTIVE: To determine the efficacy and safety of stent placement in patients with ARAS and impaired renal function. DESIGN: Randomized clinical trial. Randomization was centralized and computer generated, and allocation was assigned by e-mail. Patients, providers, and persons who assessed outcomes were not blinded to treatment assignment. SETTING: 10 European medical centers. PARTICIPANTS: 140 patients with creatinine clearance less than 80 mL/min per 1.73 m(2) and ARAS of 50% or greater. INTERVENTION: Stent placement and medical treatment (64 patients) or medical treatment only (76 patients). Medical treatment consisted of antihypertensive treatment, a statin, and aspirin. MEASUREMENTS: The primary end point was a 20% or greater decrease in creatinine clearance. Secondary end points included safety and cardiovascular morbidity and mortality. RESULTS: Forty-six of 64 patients assigned to stent placement had the procedure. Ten of the 64 patients (16%) in the stent placement group and 16 patients (22%) in the medication group reached the primary end point (hazard ratio, 0.73 [95% CI, 0.33 to 1.61]). Serious complications occurred in the stent group, including 2 procedure-related deaths (3%), 1 late death secondary to an infected hematoma, and 1 patient who required dialysis secondary to cholesterol embolism. The groups did not differ for other secondary end points. LIMITATION: Many patients were falsely identified as having renal artery stenosis greater than 50% by noninvasive imaging and did not ultimately require stenting. CONCLUSION: Stent placement with medical treatment had no clear effect on progression of impaired renal function but led to a small number of significant procedure-related complications. The study findings favor a conservative approach to patients with ARAS, focused on cardiovascular risk factor management and avoiding stenting.

Daily nighttime melatonin reduces blood pressure in male patients with essential hypertension.

Abstract—Patients with essential hypertension have disturbed autonomic cardiovascular regulation and circadian pacemaker function. Recently, the biological clock was shown to be involved in autonomic cardiovascular regulation. Our objective was to determine whether enhancement of the functioning of the biological clock by repeated nighttime melatonin intake might reduce ambulatory blood pressure in patients with essential hypertension. We conducted a randomized, double-blind, placebo-controlled, crossover trial in 16 men with untreated essential hypertension to investigate the influence of acute (single) and repeated (daily for 3 weeks) oral melatonin (2.5 mg) intake 1 hour before sleep on 24-hour ambulatory blood pressure and actigraphic estimates of sleep quality. Repeated melatonin intake reduced systolic and diastolic blood pressure during sleep by 6 and 4 mm Hg, respectively. The treatment did not affect heart rate. The day–night amplitudes of the rhythms in systolic and diastolic blood pressures were increased by 15% and 25%, respectively. A single dose of melatonin had no effect on blood pressure. Repeated (but not acute) melatonin also improved sleep. Improvements in blood pressure and sleep were statistically unrelated. In patients with essential hypertension, repeated bedtime melatonin intake significantly reduced nocturnal blood pressure. Future studies in larger patient group should be performed to define the characteristics of the patients who would benefit most from melatonin intake. The present study suggests that support of circadian pacemaker function may provide a new strategy in the treatment of essential hypertension.

European Society of Hypertension practice guidelines for ambulatory blood pressure monitoring

Given the increasing use of ambulatory blood pressure monitoring (ABPM) in both clinical practice and hypertension research, a group of scientists, participating in the European Society of Hypertension Working Group on blood pressure monitoring and cardiovascular variability, in year 2013 published a comprehensive position paper dealing with all aspects of the technique, based on the available scientific evidence for ABPM. The present work represents an updated schematic summary of the most important aspects related to the use of ABPM in daily practice, and is aimed at providing recommendations for proper use of this technique in a clinical setting by both specialists and practicing physicians. The present article details the requirements and the methodological issues to be addressed for using ABPM in clinical practice, The clinical indications for ABPM suggested by the available studies, among which white-coat phenomena, masked hypertension, and nocturnal hypertension, are outlined in detail, and the place of home measurement of blood pressure in relation to ABPM is discussed. The role of ABPM in pharmacological, epidemiological, and clinical research is also briefly mentioned. Finally, the implementation of ABPM in practice is considered in relation to the situation of different countries with regard to the reimbursement and the availability of ABPM in primary care practices, hospital clinics, and pharmacies.

Circadian Profile of Systemic Hemodynamics

We determined the continuous 24-hour profile of mean arterial pressure, heart rate, stroke volume, cardiac output, and total peripheral resistance in eight healthy ambulatory volunteers. Beat-to-beat intra-arterial blood pressure was recorded with the Oxford system; subjects were ambulant during daytime and slept at night. Beat-to-beat stroke volume was determined by the pulse contour method from the arterial pulse wave. During the nighttime, compared with the daytime average, there was a decrease in blood pressure (9 mm Hg), heart rate (18 beats per minute), and cardiac output (29%); stroke volume showed a small decrease (7%), and total peripheral resistance increased unexpectedly by 22%. When subjects arose in the morning a steep increase in cardiac output and decrease in total peripheral resistance were found. Comparable changes were seen during a period of supine resting in the afternoon, whereas physical exercise caused opposite changes in hemodynamics. This pattern was observed in all subjects. We conclude that the circadian pattern of cardiac output and total peripheral resistance originates from the day-night pattern in physical activity: during the nighttime, blood flow to the skeletal muscles is decreased through local autoregulation, which increases total peripheral resistance and decreases cardiac output compared with the daytime.

Microalbuminuria in Adults after Prenatal Exposure to the Dutch Famine

Maternal undernutrition during gestation is associated with an increase in cardiovascular risk factors in the offspring in adult life. The effect of famine exposure during different stages of gestation on adult microalbuminuria (MA) was studied. MA was measured in 724 people, aged 48 to 53, who were born as term singletons in a university hospital in Amsterdam, the Netherlands, around the time of the Dutch famine 1944 to 1945. Twelve percent of people who were exposed to famine in mid gestation had MA (defined as albumin/creatinine ratio >/=2.5) compared with 7% of those who were not prenatally exposed to famine (odds ratio 2.1; 95% confidence interval 1.0 to 4.3). Correcting for BP, diabetes, and other influences that affect MA did not attenuate this association (adjusted odds ratio 3.2; 95% confidence interval 1.4 to 7.7). The effect of famine was independent of size at birth. Midgestation is a period of rapid increase in nephron number, which is critical in determining nephron endowment at birth. Fetal undernutrition may lead to lower nephron endowment with consequent MA in adult life.

Impaired Cerebral Autoregulation in Patients With Malignant Hypertension

Background—In patients with a malignant hypertension, immediate parenteral treatment with blood pressure–lowering agents such as intravenous sodium nitroprusside (SNP) is indicated. In this study, we evaluated static and dynamic cerebral autoregulation (CA) during acute blood pressure lowering with SNP in these patients. Methods and Results—In 8 patients with mean arterial pressure (MAP) >140 mm Hg and grade III or IV hypertensive retinopathy at hospital admission, middle cerebral artery blood velocity (MCA V) and blood pressure were monitored. Dynamic CA was expressed as the 0.1-Hz MCA Vmean to MAP phase lead and static CA as the MCA Vmean to MAP relationship during SNP treatment. Eight normotensive subjects served as a reference group. In the patients, the MCA Vmean to MAP phase lead was lower (30±8° versus 58±5°, mean±SEM; P<0.05), whereas the transfer gain tended to be higher. During SNP treatment, target MAP was reached within 90 minutes in all patients. The MCA Vmean decrease was 22±4%, along with a 27±3% reduction in MAP (from 166±4 to 121±6 mm Hg; P<0.05) in a linear fashion (averaged slope, 0.82±0.15% cm · s−1 · % mm Hg−1; r=0.70±0.07). Conclusions—In patients with malignant hypertension, dynamic CA is impaired. An MCA Vmean plateau was not detected during the whole SNP treatment, indicating loss of static CA as well. This study showed that during the whole rapid reduction in blood pressure with SNP, MCA Vmean decreases almost one on one with MAP.

Nexfin noninvasive continuous blood pressure validated against Riva-Rocci/Korotkoff.

BACKGROUND The Finapres methodology offers continuous measurement of blood pressure (BP) in a noninvasive manner. The latest development using this methodology is the Nexfin monitor. The present study evaluated the accuracy of Nexfin noninvasive arterial pressure (NAP) compared with auscultatory BP measurements (Riva-Rocci/Korotkoff, RRK). METHODS In supine subjects NAP was compared to RRK, performed by two observers using an electronic stethoscope with double earpieces. Per subject, three NAP-RRK differences were determined for systolic and diastolic BP, and bias and precision of differences were expressed as median (25th, 75th percentiles). Within-subject precision was defined as the (25th, 75th percentiles) after removing the average individual difference. RESULTS A total of 312 data sets of NAP and RRK for systolic and diastolic BP from 104 subjects (aged 18-95 years, 54 males) were compared. RRK systolic BP was 129 (115, 150), and diastolic BP was 80 (72, 89), NAP-RRK differences were 5.4 (-1.7, 11.0) mm Hg and -2.5 (-7.6, 2.3) mm Hg for systolic and diastolic BP, respectively; within-subject precisions were (-2.2, 2.3) and (-1.6, 1.5) mm Hg, respectively. CONCLUSION Nexfin provides accurate measurement of BP with good within-subject precision when compared to RRK.

Prevalence, awareness, treatment, and control of hypertension among Black Surinamese, South Asian Surinamese and White Dutch in Amsterdam, The Netherlands: the SUNSET study

Objective To assess ethnic differences in prevalence, levels of awareness, treatment and control of hypertension among Dutch ethnic groups and to determine whether these differences are consistent with the UK findings. Design Cross-sectional survey. Setting South-east Amsterdam, The Netherlands. Participants A random sample of 1383 non-institutional adults aged 35–60 years. Of these, 36.7% were White, 42% were Black and 21.3% were South Asian people. Main outcome measures Prevalence of hypertension, rates of awareness, treatment, and control of hypertension. Results The Black and South Asian subjects had a higher prevalence of hypertension compared with White people. After adjustments for age, the odds ratios (95% confidence interval) for being hypertensive were 2.2 (1.4–3.4; P < 0.0001) and 3.8 (2.6–5.7; P < 0.0001) for Black men and women, respectively, and 1.7 (1.0–2.6; P = 0.039) and 2.8 (1.8–4.5; P < 0.0001) for South Asian men and women, compared with White people. There were no differences in awareness and pharmacological treatment of hypertension between the groups. However, Black hypertensive men 0.3 (0.1–0.7; P < 0.01) and women 0.5 (0.3–0.9; P < 0.05) were less likely to have their blood pressure adequately controlled compared with White people. Conclusion The higher prevalence of hypertension found among Black and South Asian people in The Netherlands is consistent with the UK studies. However, the lower control rates and the similar levels of awareness and treatment of hypertension in Black Surinamese contrast with the higher rates reported in African Caribbeans in the UK. The rates for the South Asians in The Netherlands were relatively favourable compared to similar South Asian groups in the UK. These findings underscore the urgent need to develop strategies aimed at improving the prevention and control of hypertension, especially among Black people, in The Netherlands.

Maternal nutrition during gestation and blood pressure in later life.

Objective To assess the link between maternal diet during pregnancy and blood pressure of the offspring. Design Follow-up study. Setting A university hospital in Amsterdam, The Netherlands. Participants People born at term as singletons between November 1943 and February 1947. Main outcome measure Blood pressure at adult age. Results Adult blood pressure was not associated with protein, carbohydrate or fat intake during any period of gestation. We found, however, after adjustment for sex that the systolic blood pressure decreased by 0.6 mmHg (0.1–1.1) for every 1% increase in protein/carbohydrate ratio in the third trimester. This association was present both in people who had been exposed to the famine during gestation as well as in those who had not been exposed. The association between protein/carbohydrate ratio in the third trimester and adult blood pressure was furthermore independent of maternal weight gain and final weight, and birth weight [increase for every 1% increase in protein/carbohydrate ratio 0.6 mmHg (0.0–1.2)]. Adjustment for adult characteristics such as body mass index, smoking and socio-economic status did not affect the observed association appreciably [adjusted increase 0.5 mmHg (0.0–1.0)]. Conclusion Adult blood pressure seems to be affected by small variations in the balance of macro-nutrients in the maternal diet during gestation rather than by relatively large variations in the absolute amounts.

Oscillometric blood pressure measurement: progress and problems

Oscillometric blood pressure measurement has become very popular, but although a number of devices have now passed both the Association for the Advancement of Medical Instrumentation and British Hypertension Society criteria, complacency with the state of the technique is as yet premature. In indivi