[Hypertension in solid organ transplants]

Hypertension is highly prevalent in transplantation and affects all type of organs. With the introduction of calcineurin inhibitors as immunosuppressive drugs, acute allograft rejection episodes have been significantly reduced and hence patient and allograft survival rates have dramatically improved. However, cardiovascular complications have become an important cause of morbidity and mortality. Treating cardiovascular risk factors such as diabetes, dyslipidemia and hypertension seems obvious, however in this population, there is little evidence for specific blood pressure targets, or for the best strategy to achieve blood pressure control. The aim of this article is to review the epidemiology and physiopathology of hypertension in transplant recipients as well as its clinical management.

[Hypertension genetics: what have we learned so far?]

Hypertension is a common, modifiable and heritable cardiovascular risk factor. Some rare monogenic forms of hypertension have been described, but the majority of patients suffer from "essential" hypertension, for whom the underlying pathophysiological mechanism is not clear. Essential hypertension is a complex trait, involving multiple genes and environmental factors. Recently, progress in the identification of common genetic variants associated with blood pressure and hypertension has been made thanks to large-scale international collaborative projects involving geneticists, epidemiologists, statisticians and clinicians. In this article, we review some basic genetic concepts and the main research methods used to study the genetics of hypertension, as well as selected recent findings in this field.

Issues in blood pressure control and the potential role of single-pill combination therapies

Hypertension (HTN) is a major risk factor for cardiovascular mortality, yet only a small proportion of hypertensive individuals receive appropriate therapy and achieve target blood pressure (BP) values. Factors influencing the success of antihypertensive therapy include physicians' acceptance of guideline BP targets, the efficacy and tolerability of the drug regimen, and patient compliance and persistence with therapy. It is now well recognised that most hypertensive patients require at least two antihypertensive agents to achieve their target BP. However, complicated treatment regimens are a major contributory factor to poor patient compliance. The use of combination therapy for HTN offers a number of advantages over the use of monotherapy, including improved efficacy, as drug combinations with a synergistic mechanism of action can be used. This additive effect means that lower doses of the individual components can be used, which may translate into a decreased likelihood of adverse events. The use of single-pill combination therapy, in which two or more agents are combined in a single dosage form, offers all the benefits of free combination therapy (improved efficacy and tolerability over monotherapy) together with the added benefit of improved patient compliance because of the simplified treatment regimen. The use of single-pill combination therapy may also be associated with cost savings compared with the use of free combinations for reasons of cheaper drug costs, fewer physician visits and fewer hospitalisations for uncontrolled HTN and cardiovascular events. Thus, the use of single-pill combination therapy for HTN should help improve BP goal attainment through improved patient compliance, leading to reduced costs for cardiovascular-related care.

[Intermittent hemodialysis in the intensive care setting]

Acute renal failure is a frequent and potentially lethal disease in intensive care units. Renal replacement therapy (RRT) is often required. Either intermittent or continuous methods of RRT can be used. When to start a RRT and which method to use is not always clearly defined and a global evaluation of the clinical situation is required. The choice of the modality of RRT will be up to the general clinical context, hemodynamic stability, the type of molecules to be cleared and the haemorrhagic risk as much as habits and available resources. No study currently showed a superiority of either continuous or intermittent renal replacement therapy. The collaboration between intensive care specialists and nephrologists allows an optimized choice for a given patient and allow better move from one technic to another if required.

[Plasmapheresis, a safe treatment when applied to the correct indication and with awareness of the complications]

Plasmapheresis is an extracorporeal technique used to remove pathogenic macromolecules from the circulation, particularly autoantibodies. This is illustrated in 2 female patients. The first patient, aged 61 years, was treated successfully with non-selective plasmapheresis for acute humoral rejection shortly after receiving a renal allograft. In the second patient, aged 82 years, plasmapheresis for refractory myasthenia gravis had to be stopped because of bradycardia and hypotension during the procedure. She was treated successfully with immunoglobulins. Plasmapheresis is used to treat neurological, renal, haematological and systemic disorders. In nonselective plasmapheresis, the plasma is replaced with saline and albumin or donor plasma. In selective plasmapheresis a highly selective filter is used to remove a specific, pathogenic macromolecule. Adverse effects of the treatment include disturbances of the acid-base equilibrium or the coagulation, and allergic reactions. Most of these complications, however, can nowadays be avoided.

[Treatment of patients at high cardiovascular risk: confirmation and surprising results of the ONTARGET-Study]

Am letzten Kongress des American College of Cardiology (ACC) wurden die Resulate der ONTARGET-Studie präsentiert. Diese klinische Studie mit über 25 000 kardiovaskulären Hochrisikopatienten verglich die Wirkung von Ramipril 10 mg mit Telmisartan 80 mg und der Kombination von Ramipril 10mg/Telmisartan 80 mg in der Prävention von kardiovaskulären Komplikationen (Myokardinfarkt, zerebrovaskuläre Ereignisse, Hospitalisation wegen Herzinsuffizienz und kardiovaskuläre Mortalität). Die Resultate der Studie haben gezeigt, dass Telmisartan die gleiche Wirksamkeit wie Ramipril hat, Telmisartan aber besser toleriert wird. Die Daten dieser Studie zeigen auch den fehlenden Nutzen einer Kombinationstherapie mit Ramipril und Telmisartan in dieser Patientengruppe, trotz einer leicht besseren Blutdruckkontrolle. Jedoch waren die Nebenwirkungen unter der Kombinationstherapie häufiger als unter Telmisartan oder Ramipril allein. Die Daten zeigen somit die Wirksamkeit von Telmisartan und von Ramipril in der Prävention der kardiovaskulären Ereignisse beim Hochrisikopatienten.

[Need of antihypertensive therapy in patients aged 80 years or more]

Die HYVET-Studie hatte das Ziel zu prüfen, ob eine antihypertensive Therapie auch beim Patienten von 80 und mehr Jahren einen Nutzen hat. Die Patienten (n = 3 845) mit einem systolischen Blutdruck von 160 bis 190 mmHg und einem diastolischen Blutdruck unter 110 mmHg wurden zu Indapamid (1.5 mg/Tag), bei Bedarf in Kombination mit Perindopril (2–4 mg/Tag), oder einem Placebo randomisiert. Die Patienten wurden doppelblind während einer durchschnittlichen Beobachtungszeit von 2.1 Jahren verfolgt. Der Zielwert des Blutdrucks (<150/80 mmHg) wurde nach 2 Jahren von 48.0% der Patienten in der Behandlungsgruppe, versus 19.9% in der Placebogruppe (p < 0.001) erreicht. Das Risiko eines tödlichen zerebrovaskulären Ereignisses konnte dank der Therapie um 39% (p = 0.05), die Entwicklung einer Herzinsuffizienz (tödlich oder nicht tödlich) um 64%( p < 0.001) und die kardiovaskuläre Mortalität um 23% (p < 0.06) gesenkt werden. Die totale Mortalität konnte um 21% (p = 0.01) vermindert werden. Die medikamentöse Therapie war ebenso gut verträglich wie Placebo und war mit deutlich weniger schweren Nebenwirkungen behaftet als letzteres. Diese positiven Resultate mit einer Therapie mit Indapamid und Perindopril rechtfertigen ab jetzt eine Therapie der über 80-jährigen hypertonen Patienten.

[Plasmapheresis: technique, complications and indications]

Plasmapheresis is an extracorporeal technique used to remove pathogenic macromolecules from the plasma. Plasmapheresis is used to treat neurological, renal, hematological as well as systemic diseases, which explains why many different specialties in medicine can be involved. Plasmapheresis has evolved in forty years into a frequently used, relatively safe procedure. Nowadays a large spectrum of different techniques exists, each with its own possible complications. In this article we will give an overview of these different techniques, their complications and indications, in order to familiarize the reader with this fascinating treatment.

[Treatment of secondary hyperparathyroidism in renal insufficiency: role of calcitriol, sevelamer and cinacalcet]

Along with the decrease in kidney function arises a secondary hyperparathyroidism, which constitutes one of the most important risk factor for mortality in patients suffering from renal insufficiency. Treating secondary hyperparathyroidism is challenging, as most of the parameters of mineral metabolism are interconnected. We review here the pathophysiology and treatment options of this entity.

[Previous and new concepts in the management of symptomatic hyponatraemia]

Hyponatraemia is an electrolytic disorder whose danger is often underestimated. The treatment of symptomatic hyponatraemia has been a subject of controversy for a long time. This disorder needs to be treated aggressively and cautiously because of the associated risk of definitive neurological lesions. Recently, a number growing of studies recognised the high incidence of a concurrent condition that has to be diagnosed and treated: hypoxia.

[Pregnancy in patients with underlying renal disease]

Pregnancy has generally been regarded as very high risk in women with chronic renal insufficiency. In this review, we describe the physiologic changes in systemic and renal haemodynamics during pregnancy, as well as the nature and severity of possible maternal and foetal complications in the setting of underlying renal disease. The risks are proportional to the degree of functional renal impairment, the presence or not of proteinuria and/or arterial hypertension at the time of conception, and are related to the type of underlying nephropathy or systemic disease in the mother. Furthermore, if the renal disease has been diagnosed before pregnancy, a better planning of the moment of conception, as well as a tight follow-up, allow for a better maternal and obstetrical outcome.

Prevalence of elevated blood pressure and association with overweight in children of a rapidly developing country

We assessed the prevalence of elevated blood pressure (BP) and the association with excess body weight among a large sample of children in the Seychelles, a middle-income rapidly developing country in the African region. Weight, height and BP were measured in all children of four school grades in the Seychelles (Indian Ocean). Excess weight categories ('overweight' and 'obesity') were defined according to the criteria of the International Obesity Task Force. Two BP readings were obtained on one occasion. 'Elevated BP' was defined based on US reference tables. Data were available in 15,612 (86%) of 18,119 eligible children aged 5-16 years in 2002-2004. In all, 13.0% of Boys and 18.8% of girls were overweight or obese. The prevalence of elevated BP was 9.1% in boys and 10.1% in girls. Both systolic and diastolic BP were strongly associated with body mass index (BMI) in boys and in girls. In children with 'normal weight', 'overweight (and not obesity)' and 'obesity', respectively, proportions with elevated BP were 7.5, 16.9 and 25.2% in boys, and 7.5, 16.1 and 33.2% in girls. Overweight (including obesity) could account for 18% of cases of elevated BP in boys and 26% in girls. Further studies should examine the impact of the relationship between BMI and elevated BP on the burden of hypertension in the context of the epidemic of paediatric obesity.

[Lercanidipine, a third generation calcium antagonist. Which advantages?]

Lercanidipine is a new highly lipophylic dihydropyrdine derivative of the third generation with equal efficacy but an improved tolerability profile. Comparative therapeutic trials have shown that it is as effective as other dihydropyridines, in particular amlodipine, beta-blockers, and angiotensin-converting enzyme inhibitors. Lercanidipine is well tolerated, with most treatment-emergent events related to vasodilation. Lercanidipine produces less reflex tachycardia and peripheral oedema. Common adverse events included headache and flushing. Because of its efficacy and favorable safety profile, lercanidipine has the potential to improve blood pressure control in a wide range of patients, including those who have not responded to, or who have been unable to tolerate other antihypertensive agents.

[Health economic consequences of the use of irbesartan in patients with type 2 diabetes, hypertension and nephropathy in Switzerland]

The irbesartan in Diabetic Nephropathy Trial (IDNT) demonstrated that treatment of patients with type 2 diabetes, hypertension and nephropathy with irbesartan resulted in a 20% relative reduction of the composite endpoint of doubling serum creatinine, end-stage renal disease or death as compared with amlodipine and placebo (antihypertensive standard therapy). The objective of this study was to investigate the long-term health economic consequences of this treatment strategy in a Swiss health care setting. This analysis used a Markov model to simulate the progression of nephropathy, life-years and treatment costs over ten years for each of the three treatment options. In additon, sensitivity analyses were performed. Treatment with irbesartan will save CHF 22681/patient as compared with amlodipine and CHF 13847 as compared with standard therapy.

[Obesity: what impact on renal function?]

The increasing prevalence of obesity is a major public health concern, affecting more than one third of the Swiss population. The renal effects of obesity per se, independent of hypertenison or diabetes, though, are less known. Obesity is positively correlated with proteinuria and the development of glomerulomegaly and focal segmental glomerulosclerosis. The pathophysiology of the obesity-associated kidney disease is complex, including hemodynamic and physical factors and increased synthesis of vasoactive and fibrogenic substances by adipose tissue. The most important therapeutic approach is weight reduction. Angiotension converting enzyme (ACE) inhibition is effective in reducing proteinuria, but longer follow-up is required to determine the long term benfits of ACE inhibition.

[Chronic renal failure: what diet?]

A low protein diet has been traditionally advocated in patients with chronic renal failure (CRF), in order to slow its progression. However, CRF is often associated with malnutrition, aggravating its prognosis, especially in elderly patients. In severe CRF, the spontaneous reduction of appetite coupled with additional restrictions regarding sodium, potassium and phophates may further impact on nutrition status. The potential benefit of a low protein diet is therefore questionable. We only recommend a moderately restricted protein diet (0,8 g/kg/day) in selected patients with no sign of malnutrition. This strategy, if applied, must be supported by a multidisciplinary approach involving a nephrologist and a specialised dietician. Additional dietary restrictions are not justified, except in particular situations.

[Clinical and genetics aspects of Alport syndrome]

Microscopic haematuria of glomerular origin, without known aetiology, should raise the suspicion of Alport Syndrome IASI in children as well as in adults. The genetic mutations causing AS lie in the genes encoding for the alpha3, alpha4 and alpha5 chains of the collagen type IV, the main constituent of glomerular basement membranes (GBM). The various mutations and modes of transmission of the disease account for the heterogeneous clinical presentations. No specific treatment of AS is currently available. However, a better understanding of the GBM's ultrastructure, in particular of type IV collagen, will hopefully enable the identification of novel therapeutic targets.

[Antihypertensive therapy: who should be treated and to which target?]

There is no doubt today that hypertensive therapy is effective in preventing cardiovascular complications. Having blood pressures 140/190 mmHg repeatedly at the doctor's office is associated with an increased cardiovascular risk and requires drug treatment if non-pharmacological measures do not allow blood pressure normalization. Antihypertensive therapy might already be required in patients exhibiting simultaneously blood pressure > or = 130/180 mmHg and diabetes and/or renal disease.

[Do selective COX-2 inhibitors have adverse renal and cardiovascular effects?]

Selective cyclooxygenase-2-inhibitors (COX-2) were developed as an alternative to the non-steroidal anti-inflammatory drugs (NSAID) in order to reduce their known gastrointestinal and renal toxicity. Several recent studies have shown the complex mechanism of the cyclooxygenase-2. The inhibition of the COX-2 has effects on renal hemodynamics, renal salt and water retention and may increase the thromboembolic and therefore the cardiovascular risk. The renal toxicity of the COX-2 inhibitors is similar to that of traditional NSAID. Regarding these data, COX-2 inhibitors should be prescribed with much caution to high risk patients, that is, patients with renal failure and/or cardiovascular diseases.

[Are the guidelines for the management of hypertensive patients followed by primary care residents and fellows?]

Numerous international guidelines are published which define how hypertensive patients should be managed. Are these guidelines followed and applicable? We have assessed the quality of management of 225 hypertensive ambulatory patients followed by young fellows in teaching for primary care medicine. The control rate defined by a blood pressure < 140/90 mmHg was 32,4%. In the last three visits, 60% of hypertensive patients had a blood pressure measurement. 79% of blood pressure readings ended with 0 or 5. Blood pressure control was identical whatever the comorbidities. In conclusion, the quality of management of hypertensive patients by in teaching fellow could potentially be improved. The actual recommendations are limited in their application. The control of high risk vascular patients is not better than those with a lower risk.