Biomedical subjects

Adeera Levin

Publications and source records attributed to Adeera Levin.

61 records · Page 4Linked to original sources

PubMed2002

Barriers to blood pressure control and angiotensin enzyme inhibitor use in Canadian patients with chronic renal insufficiency.

BACKGROUND: Current recommendations for the management of chronic renal insufficiency (CRI) include the use of angiotensin-converting enzyme inhibitors (ACEI) and achieving target blood pressure control. We designed this study to describe the use of these therapeutic strategies, and to investigate barriers to their implementation. METHODS: This was a prospective study of 304 consecutive CRI patients, seen at follow-up in four nephrology clinics across Canada. The use of blood pressure control and antihypertensive medication (AHM) in each of these clinics was recorded, and a questionnaire was administered to nephrologists to determine the basis for decisions concerning AHM regimens and ACEI use/non-use. RESULTS: Mean age was 60.8+/-15.7 years, mean creatinine clearance was 30.3+/-18 ml/min, and underlying renal diseases were similar to registry data. Mean arterial pressure (MAP) achieved was 99.4+/-14.4 and 98.9+/-11.9 mmHg in individuals with >1 and </=1 g/day proteinuria, respectively. When similarly stratified by proteinuria, mean systolic blood pressures were 141.4+/-23.5 and 140.9+/-20.3 mmHg, and mean diastolic blood pressures were 78.4+/-14.0 and 77.9+/-11.4 mmHg, respectively. Blood pressure control, according to published guidelines, was achieved in 128 patients (42.1%). A further 86 (28.3%) patients had their AHM increased. The remaining 90 (29.6%) did not have their AHM increased. Of these, 40 were labelled 'at target blood pressure' (mean MAP 100.5+/-5.4 mmHg), 19 'office hypertension' and 11 'unfavourable risk/benefit ratios'. There were 108/304 (35.5%) patients who were not taking ACEI or ARB (angiotensin receptor antagonist): 34/108 (31%) had previous ACEI failure due to hyperkalaemia (21/108, 19%) or acute renal failure (17/108, 16%), and 61/108 (55%) were felt 'unlikely to benefit' (categories not mutually exclusive). Miscommunication with the primary physician and medication costs were not identified as significant barriers to improved blood pressure control or ACEI use. CONCLUSIONS: Approximately 40% of CRI patients are achieving current blood pressure goals and 64% are prescribed ACEI/ARB in tertiary care nephrology clinics. Although the use of these strategies may be increasing, there remains room for improvement. Physicians should remain aware of the need to use these proven strategies in patients with CRI.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed2002

The relationship of haemoglobin level and survival: direct or indirect effects?

The relationship between haemoglobin (Hb) level and survival in patients with chronic kidney disease (CKD) is complex. This paper explores the physiological basis for the hypothesis that Hb level and survival are causally related in this patient group, and assesses the current state of knowledge from clinical studies. Issues related to the methodology and analysis of clinical studies limit the certainty with which conclusions regarding the direct relationship between Hb level and survival can be drawn. The data support the concepts that Hb level is associated with survival in patients both with and without CKD, that changes in Hb level are associated with cardiovascular disease (CVD), and that CVD is prevalent in patients with CKD. Hb level is affected by nutritional status, inflammation, and the availability and effectiveness of human recombinant erythropoietin (rHuEPO) therapy, as well as by the degree of kidney function. Thus, the complexity of the relationships between Hb level, CVD and survival in patients with CKD requires further study from both the mechanistic and the clinical perspective. Properly designed clinical trials with survival as an endpoint, as well as data from prospectively measured modifiers of Hb levels and other markers of CVD, are needed to determine the physiological and statistical interaction of these factors in clinical practice.

Apoptosis↗

PubMed2002

Cardiovascular disease and the kidney. Tracking a killer in chronic kidney disease.

The interlinking of CVD with CKD is undeniable. CVD accounts for more than 50% of all morbidity and mortality in patients with kidney disease who have undergone renal replacement therapy, and CVD is also prevalent in patients with mild and moderately severe kidney disease. To help address the elevated risks of these patients, primary care physicians need to maintain vigilance in (1) identifying patients who have CKD and (2) implementing strategies for reducing the prevalence of CVD in this population. It is essential that patients be screened for relatively mild kidney disease by measurement of serum creatinine and urine microalbumin and by calculation of the glomerular filtration rate in mL/min/1.73 m2 using equations based on serum creatinine. Rigorous assessment of conventional risk factors, including dyslipidemia, hypertension, and diabetes, is also necessary to prevent the poor outcomes currently observed in persons with CKD. Routine use of ACE inhibitors and aspirin is encouraged in all patients with CKD, and strict glycemic and blood pressure control is recommended for optimal outcomes. In addition, patients should be screened and treated for risk factors particularly associated with kidney disease and CVD morbidity and mortality, including anemia, hyperphosphatemia, and hyperparathyroidism. Finally, physicians should be careful to avoid therapeutic nihilism in patients with kidney disease; those at highest risk of CVD are likely to receive the greatest benefit from cardiovascular therapies.

Cardiovascular Diseases↗

PubMedDate not supplied

Should hemoglobin be normalized in patients with chronic kidney disease?

In the last decade the nephrology community has learned much about the impact of anemia on patients with kidney disease. Therapy of anemia can correct many of the symptoms which seriously compromise patient function. Despite the obvious benefits, controversy continues regarding the optimal target hemoglobin concentration both in patients prior to dialysis and in dialysis populations. In this editorial we review the clinical data that contribute to this controversy and the physiologic concepts underlying the treatment of anemia. Furthermore, we discuss the need to individualize hemoglobin targets for specific patient populations and the importance of early identification and treatment of anemia in patients with kidney disease. The economic impact of normalizing hemoglobin with the use of erythropoietin and intravenous or oral iron has affected clinical practice over the last decade. Current guidelines published by Kidney Disease Outcomes and Quality Initiative (KDOQI), the European Working Group on Anemia Management, and the Canadian Society of Nephrology all recommend target hemoglobin concentrations and thresholds for initiation of therapy and also suggest the need for reevaluation of current targets in light of new evidence. This editorial supports those guidelines and challenges the reader to critically evaluate current practice in the context of the accumulating data and the physiologic principles discussed herein. The therapy of anemia in patients with chronic kidney disease (CKD) is becoming increasingly sophisticated and is an essential component of care in patients with CKD. However, the effects of therapy will be most impressive when accompanied by the optimal care of all hemodynamic and metabolic abnormalities that are associated with CKD.

Anemia↗

PubMedDate not supplied

Clinical epidemiology of cardiovascular disease in chronic kidney disease prior to dialysis.

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality in patients with end-stage renal disease (ESRD). Both in dialysis and in transplant patients, CVD remains the leading cause of death. There is accumulating evidence that the increase in CVD burden is present in patients prior to dialysis, due to both conventional risk factors as well as those specific to kidney disease. Of importance is that even in patients with mild kidney disease, the risk of cardiovascular events and death is increased relative to patients without evidence of kidney disease. The new classification system proposed by the National Kidney Foundation as part of the Dialysis Outcomes Quality Initiative (DOQI) process describes the five stages of kidney disease, as well as those complications associated with chronic kidney disease (CKD), in particular cardiovascular risk factors and disease. Patients with kidney disease are deemed to be at highest cardiovascular risk. CVD, defined as the presence of either congestive heart failure (CHF), ischemic heart disease (IHD), or left ventricular hypertrophy (LVH), is prevalent in cohorts with established CKD (8-40%). The prevalence of hypertension, a major risk factor for coronary artery disease (CAD) and LVH is high in patients with CKD (87-90%). At least 35% of patients with CKD have evidence of an ischemic event (myocardial infarction or angina) at the time of presentation to a nephrologist. The prevalence of LVH increases at each stage of CKD, reaching 75% at the time of dialysis initiation, and the modifiable risk factors for LVH include anemia and systolic blood pressure, which are also worse at each stage of kidney disease. Even under the care of nephrologists, a change in cardiac status (worsening of heart failure or anginal symptoms) occurs in 20% of patients. The presence of CVD predicts a faster decline of kidney function and the need for dialysis, after controlling for all other factors including glomerular filtration rate (GFR), age, and the presence of LVH. This article describes the new classification system for staging of CKD, defines and describes CVD in CKD, and reviews the evidence and its limitations with respect to the current understanding of CKD and CVD. Specifically, methodologic issues related to survival and referral bias limit our current understanding of the complex interaction of conventional and nonconventional kidney disease-specific risk factors. We identify the importance of well-conducted studies of patient groups with and without CVD, with and without CKD, in order to better understand the complex physiology so that treatment strategies can be appropriately applied.

Cardiovascular Diseases↗

PubMedDate not supplied

Central vein stenosis: a common problem in patients on hemodialysis.

Central vein stenosis (CVS) has been associated with subclavian (SCV) catheter insertions. The prevalence of CVS in the current era with minimal use of SCV catheters is unknown. Furthermore, the prevalence of CVS in patients with access problems has not been previously described to our knowledge. We evaluated 235 prevalent patients on hemodialysis (HD), and, of these, 133 underwent venography for access related concerns over a 14 month period. Of these 133 patients, 55 (41%) had evidence of significant CVS on venogram. Patients with CVS had a longer duration on HD (43 +/- 12 months vs. 34 +/- 15 months, p = 0.018) and a history of a previous HD catheter insertion (52/55 patients vs. 59/78 patients, p = 0.0039). There were only 18 patients with a subclavian catheter insertion. In those with any history of previous HD catheter insertion, multivariate analysis demonstrated that number of catheters remains a significant factor (OR 2.69, p = 0.0004) even after excluding those subclavian insertions. This study demonstrates that CVS occurs in almost half of the patients with access problems undergoing venography. We confirm the important contribution of central vein cannulation to CVS and show that, despite minimizing subclavian catheter insertion, CVS remains a relatively common occurrence. Thus further studies should attempt to determine the true incidence of this problem and ultimately address the optimal treatment strategies.

Aged↗

PubMedDate not supplied

The cardiovascular effects of arteriovenous fistulas in chronic kidney disease: a cause for concern?

Arteriovenous fistulas (AVFs) are the preferred type of vascular access, but relatively little is known regarding their effects on cardiovascular remodeling and cardiac function. The following is a review regarding the immediate and long-term complications associated with AVF creation, including the development of left ventricular hypertrophy, high-output cardiac failure, exacerbation of coronary ischemia, and the possible contribution to the development of central vein stenosis.

Arteriovenous Shunt, Surgical↗