Clinical significance of low-grade renal artery stenosis.

BACKGROUND: Patients with a renal artery stenosis (RAS) >50% carry an increased risk for future cardiovascular (CV) events. Experimental literature on this topic suggests that this might as well be true for subjects with lower-grade RAS. METHODS: Recruitment in this longitudinal cohort study was conducted from 1982 to 2002 in a Dutch University Hospital. Included in this study were 301 hypertensive patients clinically suspected of having RAS. Study participants were radiologically classified as having no, a low-grade (<50% lumen narrowing) or high-grade (> or =50%) RAS. A predetermined composite CV end-point was defined as one of the following: myocardial infarction or 'objectified' angina pectoris, ischaemic stroke or death from any CV cause. Other end-points were the occurrence of CV complications, all-cause plus CV mortality and decline in renal function. RESULTS: During a median follow-up of 8.2 years, the incidence of the composite end-point totalled 79 events. After full adjustment in Cox models, a significant risk increase in high-grade [hazard ratio (HR) 2.81; P = 0.002] and low-grade RAS (HR 2.32; P = 0.038) was observed. Other end-points did not differ significantly between study groups. CONCLUSION: Hypertensive subjects with RAS of any extent, compared with hypertensives without RAS, carry a substantially increased risk for future CV events. Therefore, even in patients with low-grade RAS, aggressive pharmacological treatment strategies should be adopted as a preventive measure.

Multilayer compression bandaging in the acute phase of deep-vein thrombosis has no effect on the development of the post-thrombotic syndrome.

OBJECTIVE: The purpose of this randomized study was to evaluate the influence of immediate multilayer compression bandages before application of elastic stockings in the acute phase of deep-vein thrombosis (DVT) on development of the post-thrombotic syndrome (PTS). METHODS: Sixty-nine patients with acute symptomatic DVT were randomized to immediate bandaging (n = 34) or no bandaging (n = 35). After reduction of edema sized-to-fit elastic stockings were applied in all patients after 7-14 days. Follow-up visits and non-invasive examinations were planned after 7, 30 and 90 days and 1 year. Venous outflow resistance (VOR) was measured by strain gauge plethysmography. Thrombosis score (TS) and reflux were measured by duplex scanning. After one year patients were evaluated for clinical PTS using both the clinical scale of the CEAP classification and the Villalta score. RESULTS: Improvement of clinical symptoms and decrease of leg circumference was better on day 7 in the bandaging group, but after 1 and 3 months clinical symptoms had improved equally in both groups. In 7 patients in the no-bandaging group a bandage was applied after all because of persistent edema after 10 days. There were no differences in VOR, TS and reflux. Using the CEAP classification the incidence of PTS was 39% in patients with bandages and 42% in patients without bandages (RR 0.91, 95% CI 0.50-1.66). Using the Villalta score the incidence of PTS was resp. 29 and 33% (RR 0.87, 95% CI 0.41-1.8). There was no difference in severity of PTS. CONCLUSION: Immediate multilayer compression bandaging in the acute phase of DVT is effective in reducing edema and complaints in the first week, but has no effect on thrombus regression, valve incompetence and the development of clinical PTS after 1 year.

[Treatment of hypertension in people over 80 years should not be discontinued]. / Behandeling van hypertensie bij mensen boven de 80 jaar niet stopzetten.

The 'Hypertension in the very elderly trial' (HYVET) was designed to answer the question whether antihypertensive treatment reduces strokes (both fatal and non-fatal strokes) without increasing total mortality. A total of 3845 patients were assigned to active treatment or placebo. About 90% had a history of hypertension, 65% of which were being treated. At the start of the study all antihypertensive treatment was stopped and the subjects were randomized to either indapamide 1.5 mg with or without perindopril 2-4 mg or to identical looking placebo. After about 2 years the trial was discontinued for ethical reasons as there was less death from any cause in the intervention group. Blood pressure decreased with 30/13 mmHg in the treatment versus 15/7 mmHg in the placebo group. There was a 30% decrease of all strokes (p = 0.06) but a significant reduction in fatal strokes (p < 0.05). Unexpected was the 21% reduction in all-cause mortality (p < 0.02). The 23% reduction in the rate of cardiovascular death was not significant (p < 0.06). Heart failure and total cardiovascular events decreased (p < 0.001). There were fewer adverse effects in the treatment group (p = 0.001). In our opinion HYVET proves that antihypertensive medication should not be stopped when patients pass the age of 80 years. However, it remains to be established whether treatment should be started in new patients who present themselves with hypertension above the age of 80 years.

Does masked hypertension exist in healthy volunteers and apparently well-controlled hypertensive patients?

BACKGROUND: Home blood pressure (HB P) measurement is considered to reflect BP during the day better than office BP (OB P). But in some patients HB P is higher than OB P. This is called masked hypertension (MH). OBJECTIVE: To examine whether MH occurs in healthy volunteers and apparently well-controlled hypertensives. METHODS: 57 treated hypertensive patients and 31 healthy volunteers (27/22 men) participated. Mean age (+/- SD ) was 61 +/- 13 and 29 +/- 13 years, respectively. Patients were instructed to measure their BP twice daily for three days (3 readings each) with the Omron 705 CP device after at least 10 minutes rest in a comfortable sitting position. In the outpatient department, OB P was measured four times, in duplicate, every ten minutes by the physician using the same device and under similar conditions. RESULTS: Mean HB P of the treated hypertensive group was 146/84 +/- 18/10 mmHg, significantly higher than OB P 136/79 +/- 19/10 (p.

The effect of arginine vasopressin on endothelin production in the human forearm vascular bed.

OBJECTIVES: To study whether arginine vasopressin (AVP) can stimulate endothelin production and/or release in vivo, in the human forearm vasculature. DESIGN: The effect of the infusion of AVP into the brachial artery on endothelin production across the human forearm vascular bed was studied in healthy male volunteers, and was compared with intra-arterial infusion of placebo. In another group the effects of AVP on endothelin production were studied after a prior infusion of L-NG-monomethyl-arginine (L-NMMA), a nitric oxide-synthase inhibitor. In a fourth group the effect of L-NMMA alone, without AVP infusion, on endothelin production was studied. METHODS: We measured the effects of AVP, placebo, L-NMMA followed by AVP and L-NMMA followed by placebo on arterial and venous endothelin concentrations in the forearm of four groups, each consisting of five healthy male volunteers. Forearm blood flow was measured by strain gauge plethysmography. The endothelin production was calculated as forearm blood flow times (venous - arterial) endothelin concentration. RESULTS: The group infused with L-NMMA followed by infusion of 8 ng AVP/min per dl forearm volume showed a significant rise in endothelin production from 1.3 (1.8) to 5.0 (2.0) pg/min/dl at 15 minutes (p<0.05, ANOVA). This rise in endothelin production was also significantly different from the endothelin production at 15 minutes in the other three groups (p<0.01, ANOVA). CONCLUSION: In healthy male volunteers intra-arterial infusion of AVP induced a rise in endothelin production in the forearm within 15 minutes, but only after prior infusion of L-NMMA. This observation suggests that the AVP-induced production of nitric oxide offsets AVP-mediated release of endothelin.

Both body and arm position significantly influence blood pressure measurement.

The position of both the body and the arm during indirect blood pressure (BP) measurement is often neglected. The aim of the present study was to test the influence of the position of the patient on BP readings: (1) sitting with the arms supported precisely at the right atrium level and (2) supine: (a) with the arms precisely at the right atrium level and (b) with the arms on the examination bed. In a first group of 57 hypertensive patients, two sessions of BP and heart rate (HR) measurements were performed in two positions: sitting and supine with the arms supported precisely at right atrium level in both positions. BP was measured simultaneously at both arms, with a Hawksley Random Zero sphygmomanometer at the right arm, and with an automated oscillometric device (Bosomat) at the left arm. BP and HR readings obtained in the two positions were then compared. In a second group of 25 normo- and hypertensive persons, two sessions of BP and HR readings were performed in supine with the arms in two different arm positions: (a) the arm placed precisely at right atrium level and (b) the other arm on the examination bed. The measurements were performed at both arms with two automated devices (Bosomat). The readings taken in the two positions were compared. Both systolic BP (SBP; by 9.5 +/- 9.0 (standard deviation, s.d.); right arm) and diastolic BP (DBP; by 4.8 +/- 6.0 mmHg; right arm) were significantly higher in the supine than in the sitting position. When the two different arm positions (body continously supine) were compared in the second part of the study, significantly higher SBP (by 4.6 +/- 6.1 mmHg) and DBP (by 3.9 +/- 2.8 mmHg) were obtained when the arm of the patient was placed on the bed (below the right atrium level), than when the arm was placed at the level of the right atrium. BP readings in sitting and supine positions are not the same. When according to guidelines the arm of the patient is meticulously placed at the right atrium level in both positions, the difference is even greater than when the arm rests on the desk or on the arm support of the chair. Moreover, in the supine position small but significant differences in BP are measured between arm on a 5 cm-high pillow and arm on the bed. In every study reporting BP values, the position of both the body and especially the arm should be precisely mentioned.

The benefit of STent placement and blood pressure and lipid-lowering for the prevention of progression of renal dysfunction caused by Atherosclerotic ostial stenosis of the Renal artery. The STAR-study: rationale and study design.

BACKGROUND: Atherosclerotic renal artery stenosis (ARAS) is associated with progressive loss of renal function and is one of the most important causes of renal failure in the elderly. Current treatment includes restoration of the renal arterial lumen by endovascular stent placement. However, this treatment only affects damage caused by ARAS due to the stenosis and ensuing post-stenotic ischemia. ARAS patients have severe general vascular disease. Atherosclerosis and hypertension can also damage the kidney parenchyma causing renal failure. Medical treatment focuses on the latter. Lipid-lowering drugs (statins) could reduce renal failure progression and could reduce the overall high cardiovascular risk. The additional effect on preserving renal function of stent placement as compared to medical therapy alone is unknown. Therefore, the STAR-study aims to compare the effects of renal artery stent placement together with medication vs. medication alone on renal function in ARAS patients. METHOD: Patients with an ARAS of > or = 50% and renal failure (creatinine (Cr) clearance < 80 mL/min/1.73 m2) are randomly assigned to stent placement with medication or to medication alone. Medication consists of statins, anti-hypertensive drugs and antiplatelet therapy. Patients are followed for 2 yrs with extended follow-up to 5 yrs. The primary outcome of this study is a reduction in Cr clearance > 20% compared to baseline. This trial will include 140 patients.

Home blood pressure measurement with oscillometric upper-arm devices.

The market for automated blood pressure measuring devices is growing rapidly. Many patients want to buy a device for blood pressure measurement at home and ask their physician for advice about which one to choose. In this article an overview is given of the different devices available for blood pressure measurement and possible pitfalls in the interpretation of measurements taken at home are pointed out. A second article will specifically address those devices that are used to take blood pressure measurements at the wrist.

Oscillometric wrist blood pressure measuring devices.

Devices measuring blood pressure oscillometrically at the wrist are becoming more and more popular. These devices are small, easy to handle and can measure blood pressure without the need to undress. However, few of the wrist devices have been validated properly, i.e. according to internationally accepted protocols. In this article current literature on wrist blood pressure measuring devices is presented. The importance of positioning the wrist at heart level for accurate measurements is stressed.

Abstract!

With the availability of electronic databases, it has become crucial to provide informative abstracts to published papers. Articles published without an abstract run a great risk of being neglected by readers and authors. The Netherlands Journal of Medicine will provide informative abstracts of all future papers, including editorials and letters.

Two years of smoking cessation does not reduce arterial wall thickness and stiffness.

BACKGROUND: Smoking cessation rapidly reduces cardiovascular risk. The pathophysiological mechanisms involved are still being debated. We measured structural and functional arterial wall properties of the femoral and carotid arteries after smoking cessation to investigate their possible role in cardiovascular risk reduction. METHODS: Out of 127 smokers, 33 proved to stop smoking for two years. They were compared with 50 nonsmokers and 55 persistent smokers in a prospective study. Cross-sectional compliance and distensibility coefficients as well as intima-media thickness of both carotid arteries and of the right common femoral artery were measured ultrasonographically at baseline and 3, 6, 12 and 24 months after smoking cessation. The nonsmoking and persistent smokers group were measured twice at an interval of 24 months. RESULTS: Persistent smoking and two years of smoking cessation did not affect cross-sectional compliance and distensibility coefficients. Although at baseline intimal-medial layers were thicker in smokers, the change over time in intima-media thickness did not differ significantly between all three groups. CONCLUSION: Two years of smoking cessation was not accompanied by a slower progression or a regression in intima-media thickness nor by an improved cross-sectional compliance or distensiblity coefficient. Nevertheless, smoking cessation should be recommended as it reduces cardiovascular risk rapidly after smoking cessation.

The StethoDop: a Doppler stethoscope attachment for investigation of arterial and venous insufficiency of the lower extremities.

BACKGROUND: The aim of the current study was to investigate whether the StethoDop can serve as a valid and reproducible instrument for measuring the ankle-brachial index (ABI) and assessing venous reflux, even when used by inexperienced investigators, in comparison with the classic Doppler. METHODS: I) During four weeks, four ankle-brachial index (ABI) measurements were performed on 44 patients: one measurement with the classic Doppler by an experienced investigator, one with the classic Doppler by an inexperienced investigator and two measurements with the StethoDop by the inexperienced investigator. II) 36 patients were screened for venous insufficiency by detecting venous reflux with the StethoDop and classic Doppler at the saphenofemoral and saphenopoplitial junctions by an inexperienced investigator. The results were compared with the results of the duplex as gold standard and with the results of the examination by an experienced dermatologist with the classic Doppler. RESULTS: I) The confidence interval of ABI measurement for both the classic Doppler and the StethoDop by the inexperienced investigator was within an acceptable +/- 0.21 interval of significant change. II) For venous reflux determination, the overall sensitivity and specificity of the StethoDop were comparable with the sensitivity and specificity of the classic Doppler: sensitivity 76.0 and 75.0%, specificity 94.8 and 94.2%, respectively. The positive predictive value of the StethoDop, compared with the duplex, was 87.5%; the negative predictive value was 90.0%. CONCLUSION: I) For ABI measurement, the StethoDop is a valid instrument with reproducible results, even when used by inexperienced investigators. II) For venous reflux determination, the StethoDop is a valid screening instrument for venous insufficiency. However, as with determination with the classic Doppler, the reflux assessment by StethoDop gives no information about the deep veins and may miss up to 24% of apparent reflux.

[Reduced risk of stroke recurrence due to hypotensive medication, irrespective of the initial blood pressure]. / Minder kans op een recidiefberoerte door bloeddrukverlagende medicatie, ongeacht de uitgangsbloeddruk.

The 'Perindopril protection against recurrent stroke study' (PROGRESS) demonstrated that for patients with a history of stroke or transient ischaemic attack during the previous 5 years, a blood-pressure-lowering regimen based on the combination of a diuretic and an angiotensin-converting enzyme (ACE) inhibitor, reduces the risk of stroke recurrence (fatal and non-fatal) by 28% (95%-CI: 17-38). This effect was irrespective of the initial neurological diagnosis (ischaemic or haemorrhagic stroke) and blood pressure level. Patients who were treated with just the ACE inhibitor did not exhibit these effects. This large-scale clinical trial demonstrates that hypotensive medication in the form of a diuretic combined with an ACE inhibitor is a beneficial strategy for the secondary prevention of stroke in normotensive and hypertensive patients.

[Hypertension: once primary, always primary?]. / Hypertensie: eens primair, altijd primair?

Three patients diagnosed with primary hypertension suddenly developed hard-to-treat blood pressure after several years of stable blood pressure. One patient, a man aged 48 years, had developed a renal artery stenosis, which had not been present five years earlier. The other two patients, a man aged 57 years and a woman aged 27 years, were diagnosed with an aldosterone-producing adenoma of the left adrenal gland and a pheochromocytoma, respectively. In patients with previously stable blood pressure, sudden derangement may be due to secondary hypertension on top of the pre-existing primary hypertension. A thorough history and physical examination together with limited laboratory investigations usually leads the way to the correct diagnosis.

[Acetylsalicylic acid in primary prevention of cardiovascular events; literature study]. / Acetylsalicylzuur bij de primaire preventie van cardiovasculaire aandoeningen; literatuurstudie.

OBJECTIVE: To evaluate literature data on the use of acetylsalicylic acid (ASA) as a primary prevention measure for cardiovascular events. DESIGN: Literature search. METHOD: Using Medline, all randomised placebo-controlled trials of ASA published between 1985 and 1 May 2001, and which used cardiovascular morbidity and death as outcome measures were identified (search query: 'aspirin' and 'primary prevention'). Using the raw data presented in the source publication on death, fatal and non-fatal myocardial infarctions and cerebrovascular accidents (CVAs), all relative and absolute risk reductions were recalculated with confidence intervals. RESULTS: In healthy middle-aged men, men with an increased cardiovascular risk profile and persons with diabetes mellitus or hypertension, the use of ASA reduces the incidence of myocardial infarction and has a neutral effect on cerebrovascular events. The protective effect of ASA seemed most marked in those persons with an increased risk of manifest atherosclerotic vascular disease. CONCLUSION: Notwithstanding these findings, for each patient it remains essential to weigh up the cardiovascular risk profile against the small increased risk of complications when prescribing ASA.

The prevalence of renal artery stenosis among patients with diabetes mellitus.

BACKGROUND: Patients with diabetes mellitus (DM) have a high prevalence of atherosclerotic vascular lesions. It is therefore reasonable to assume that also the rate of renal artery stenosis (RAS) is higher. The presence of a RAS can have implications for the treatment of patients with diabetes mellitus and hypertension and renal impairment. Therefore it is important to be informed about the chance that a RAS is present among such patients. METHODS: We prospectively studied the prevalence of atherosclerotic renal artery stenosis (RAS) among patients with diabetes mellitus. Patients were included if they were diagnosed with DM and hypertension with or without impairment of renal function. If causes of renal disease other than DM or hypertension were more probable on the basis of biochemical data, then such patients were excluded. A magnetic resonance angiography (MRA) of the renal arteries was made in 54 included successive patients. PATIENT CHARACTERISTICS: mean age 59 ± 8.5 years (range 35 to 80). Eight patients had DM 1 and 46 DM 2. Mean BMI was 31.4 ± 5.6 kg/m(2). A RAS was present in 18 of the 54 (33%) patients, 3 patients had bilateral stenoses. Factors related to the presence of RAS were diastolic blood pressure, glomerular filtration rate and dyslipidaemia. CONCLUSION: In this group of diabetic patients with hypertension and or renal impairment the prevalence of RAS was 33%.