Incidental atherosclerotic renal artery stenosis in patients undergoing elective coronary angiography: are these lesions significant?

BACKGROUND: Cardiologists often identify atherosclerotic renal artery stenosis (ARAS) during cardiac angiography. The importance of such 'incidental' ARAS (iARAS) is not known. The present study sought to describe renal perfusion using non-captopril (baseline) nuclear renograms in patients with iARAS, and to determine characteristics associated with a positive captopril renogram. METHODS: Patients presenting for non-emergent coronary angiography between June 2001 and February 2006 were angiographically screened for iARAS. Those with >50% stenosis of one or both renal arteries were referred to nephrology and underwent nuclear renography. RESULTS: 131 patients had renograms. The mean age was 73.2 +/-8.1 and median eGFR was 51.2 (40.0, 66.6) ml/min/1.73 m(2). 51% had evidence of reduced perfusion to one kidney, of which 13% were discordant with the angiographic lesion. 9% had positive captopril renograms. Captopril renogram positivity was associated with severe unilateral stenosis (p = 0.02). CONCLUSIONS: In cardiac patients diagnosed with iARAS, the presence of known anatomic lesions did not correlate with captopril renogram positivity. Uncertainty remains as to whether nuclear renography is a poor functional test in this population, or the lesions are not functionally significant. These results lead us to question both the significance of such lesions, and the utility of conducting renograms in this population.

A dedicated vascular access program can improve arteriovenous fistula rates without increasing catheters.

PURPOSE: We describe the development and implementation of a comprehensive multidisciplinary vascular access (VA) program and describe its impact on VA distribution rates. METHODS: A retrospective review of all incident and prevalent patients in our hemodialysis (HD) unit was conducted in September 2001 to determine baseline data including: type of VA along with patient characteristics and comorbidities. Similar data was extracted from the database in 2005 for incident and prevalent patients. RESULTS: The VA program had a significant impact on arteriovenous fistulae (AVF) rates in both incident and prevalent HD patients: incident AVF rates increased from 14 to 39% (p=0.04) and prevalent AVF rates from 60 to 64% (p=0.015). Multivariate analysis revealed that male gender (OR 1.79 [CI 0.85-0.98, p=0.006]) and year of dialysis initiation 2005 vs. 2001 (OR 1.65 [CI 1.09-2.5, p=0.017]) were associated with AVF use among prevalent HD patients. Furthermore, age (per 5 years over 70) is associated with a decreased likelihood of having an AVF (OR 0.91 [CI 0.85-0.98, p=0.009]) whereas comorbidities of cardiovascular disease and diabetes had no impact. CONCLUSION: We demonstrate that a structured VA program can increase the number of functioning fistulas without a corresponding increase in catheters in incident and prevalent HD patients.

Stenosis at the area of transposition - an under-recognized complication of transposed brachiobasilic fistulas.

BACKGROUND: With an increased focus on native AV fistula creation in hemodialysis patients, a transposed brachiobasilic fistula (tBBF) is becoming an increasingly utilized option. This study describes the outcomes of tBBFs in a chronic hemodialysis population. In particular, we focus on the incidence and location of stenosis, and review the impact of angioplasty on these lesions. METHODS: A retrospective cohort study using all patients with a tBBF created between January 2001 and December 2004. RESULTS: Of the 543 fistulas created during the study period, 93 were tBBFs. The mean age of patients was 65 years, 56% were male and 55% were diabetic. Stenosis occurred in 54% (46/85) of fistulas; the location of stenosis in the majority (74%) was at or near the area of basilic vein transposition and 50% of fistulas with stenosis in this location required three or more angioplasties. Primary (unassisted) patency was 42% at one year in this cohort. Secondary patency was 68% at 1 year and 58% and 53% at 2 and 3 years respectively. CONCLUSION: In a cohort of hemodialysis patients who received a tBBF, we describe a reasonable primary and secondary patency rate and a high rate of stenosis at the point of transposition of the basilic vein. Such stenosis usually requires multiple percutaneous or surgical interventions to ensure or reestablish conduit patency. Further study is required regarding the optimal surgical technique, monitoring, and treatment of stenosis of this fistula type including the utility of repeat angioplasty.

Heavy chain deposition disease: recurrence in a renal transplant and report of IgG(2) subtype.

Heavy chain deposition disease (HCDD) is a rare entity characterized by tissue deposition of monoclonal heavy chains without light chains. Previous reports of HCDD include gamma(1)-, gamma(3)-, gamma(4)-, and alpha-heavy chain subtypes. Renal transplantation for HCDD has not been previously reported. We report a case of gamma(2)-HCDD in a 67-year-old patient who presented with proteinuria, hematuria, and renal insufficiency and progressed to end-stage renal failure after 6 months. The second case involves a 26-year-old woman who had a renal transplant for HCDD and recurrent gamma(1)-HCDD in the transplant. Neither patient had myeloma. The complete spectrum of gamma-HCDD subtypes has now been reported. Further data are required to make conclusive statements about the true recurrence rate of HCDD in renal transplants.

Laboratory confirmation of Amanita smithiana mushroom poisoning.

CONTEXT: Here we present a case of Amanita smithiana poisoning resulting in acute kidney injury requiring dialysis, and highlight laboratory methods used to confirm the diagnosis. Identification of Amanita smithiana toxin using thin-layer chromatography can provide greater diagnostic certainty than history and renal function tests alone. CASE DETAILS: A 63-year-old male presented to hospital with anuria and gastrointestinal symptoms, two days after consuming a soup of wild mushrooms he had picked. He was found to be in acute renal failure, requiring hemodialysis. After nine days of supportive treatment, he recovered renal function, and was discharged in good health 15 days post-ingestion. The patient provided a sample of leftover soup, and examination of cooked mushroom fragments by a mycologist provided preliminary identification of A. smithiana. Thin-layer chromatography revealed the presence of A. smithiana toxin in the soup, confirming this identification. DISCUSSION: A. smithiana is a nephrotoxic mushroom that can be easily mistaken for the edible and highly prized Pine mushroom (Tricholoma magnivelare). It causes initial gastrointestinal symptoms, followed by acute renal failure. Treatment includes dialysis and supportive care until the patient recovers renal function. The chemical structure of the A. smithiana toxin is unknown, but it can be identified as a characteristic spot on thin-layer chromatography.

Insights into the contemporary epidemiology and outpatient management of congestive heart failure.

OBJECTIVES: To evaluate the epidemiology, prognosis, and patterns of practice in patients with chronic congestive heart failure (CHF) treated and followed at a specialized clinic. METHODS: Prospective cohort study of consecutive patients referred to and followed up in a specialized heart failure clinic between September 1989 and March 1996. RESULTS: Of the 628 patients referred, 566 were confirmed to have CHF. Mean duration of follow-up was 518 +/- 490 days (range 1 to 2192 days). Vital status was available for 99.3% of patients. Mean age at enrollment was 66 years, 68% were men, 67% had an ischemic cause of heart disease, and 78% had systolic dysfunction. Patients with preserved systolic function were older, more often female, had higher mean systolic blood pressures, and a lower prevalence of ischemic heart disease, ventricular arrhythmias, or impaired renal function when compared with those with systolic dysfunction (all P