Cardiac structure and function after revascularization versus medical therapy for renal artery stenosis: the ASTRAL heart echocardiographic sub-study.

BACKGROUND: The ASTRAL trial showed no difference in clinical outcomes between medical therapy and revascularization for atherosclerotic renal vascular disease (ARVD). Here we report a sub-study using echocardiography to assess differences in cardiac structure and function at 12 months. METHODS: ASTRAL patients from 7 participating centres underwent echocardiography at baseline and 12 months after randomisation. Changes in left ventricular ejection fraction (LVEF), left ventricular mass (LVM), left atrial diameter (LAD), aortic root diameter (AoRD), E:A, and E deceleration time (EDT) were compared between study arms. Analyses were performed using t-tests and multivariate linear regression. RESULTS: Ninety two patients were included (50 medical versus 42 revascularization). There was no difference between arms in any baseline echocardiographic parameter. Comparisons of longitudinal changes in echocardiographic measurements were: δLVEF medical 0.8 ± 8.7% versus revascularization - 2.8 ± 6.8% (p = 0.05), δLVM - 2.9 ± 33 versus - 1.7 ± 39 g (p = 0.9), δLAD 0.1 ± 0.4 versus 0.01 ± 0.5 cm (p = 0.3), δAoRD 0.002 ± 0.3 versus 0.06 ± 0.3 cm (p = 0.4), δE:A - 0.0005 ± 0.6 versus 0.03 ± 0.7 (p = 0.8), δEDT - 1.1 ± 55.5 versus - 9.0 ± 70.2 ms (p = 0.6). In multivariate models, there were no differences between treatment groups for any parameter at 12 months. Likewise, change in blood pressure did not differ between arms (mean δsystolic blood pressure medical 0 mmHg [range - 56 to + 54], revascularization - 3 mmHg [- 61 to + 59], p = 0.60). CONCLUSIONS: This sub-study did not show any significant differences in cardiac structure and function accompanying renal revascularization in ASTRAL. Limitations include the small sample size, the relative insensitivity of echocardiography, and the fact that a large proportion of ASTRAL patient population had only modest renal artery stenosis as described in the main study.

Atherosclerotic renal artery stenosis: association with emerging vascular risk factors.

BACKGROUND: The established risk factors for atherosclerotic renal artery stenosis (ARAS) include hypertension, diabetes mellitus, dyslipidemia, obesity, smoking, old age and family history. In the last few years, several emerging risk factors have been proposed as predictors of ARAS, namely homocysteine, fibrinogen, C-reactive protein, lipoprotein(a) and creatinine. METHODS: We searched Pubmed/Medline for studies investigating the prognostic value of each of these emerging risk factors in ARAS. RESULTS: Creatinine and C-reactive protein seem to be the most promising predictors of ARAS, whereas the prognostic value of homocysteine, lipoprotein(a) and fibrinogen is not yet fully determined. CONCLUSION: The establishment of a definite role for these emerging risk factors could result in earlier recognition and/or better management of ARAS with potential regression/slowing down of progression of stenosis. Modifying these markers may also improve the therapeutic approach of the associated systemic atherosclerosis in these high-risk patients. Future trials should focus on the effect of different classes of drugs (e.g. statins and fibrates) on the levels of the emerging risk factors and the association with ARAS progression.

The impact of a cation channel blocker (furosemide) on Pseudomonas aeruginosa PAO1 biofilm architecture.

OBJECTIVE: To determine if furosemide could have a role in inhibition of biofilm formation. STUDY DESIGN: A prospective study of 72-hour biofilms grown in the Calgary Biofilm Device (CBD) treated with furosemide and controls. METHODS: Bacteria were treated with furosemide and controls to determine its antiplanktonic properties. PA01 biofilms were treated with serial 2-fold dilutions of furosemide and controls over a 48-hour period at pH concentrations of 7.0, 8.0, and 9.0. RESULTS: Furosemide had no effect on planktonic PA01. It had minimal effect at pH below 8.0. A pH of 8.0 and 9.0 reduced biofilms 25%. Furosemide 10 mg/mL reduced biofilms 50% at pH 8.0 and 9.0. It inhibited biofilms to < 30% at concentrations of 0.6 to 0.16 mg/mL at pH 8.0 and < 10% at concentrations of 1.25 to 0.3 mg/mL at pH 9.0. CONCLUSION: Furosemide was found to be nonantiplanktonic, but does appear to destabilize preformed PA01 biofilms at pH-dependent concentrations.

Results of Caldwell-Luc after failed endoscopic middle meatus antrostomy in patients with chronic sinusitis.

OBJECTIVES/HYPOTHESIS: The Caldwell-Luc operation for treatment of medically refractory chronic maxillary sinusitis has largely been replaced by functional endoscopic sinus surgery. Despite this change, the Caldwell-Luc procedure still has well documented indications including treatment of both failed endoscopic middle meatus antrostomy and irreversible mucosal changes. The purpose of the study was to review the authors' experience and results of Caldwell-Luc procedure after failed endoscopic middle meatus antrostomy in patients clinically deemed to have irreversible mucosal changes. STUDY DESIGN: Retrospective review of preoperative and postoperative results of patients who underwent Caldwell-Luc procedure for refractory chronic maxillary sinusitis after failed endoscopic middle meatus antrostomy. METHODS: The preoperative and postoperative clinical course of patients treated with Caldwell-Luc procedure performed by a single surgeon between 1996 and 2001 were reviewed. Only patients with a history of chronic sinusitis after failed maximal medical therapy, no prior Caldwell-Luc procedure, prior endoscopic middle meatus antrostomy, and at least 6 months of follow-up were included. Outcome measurements including documented endoscopic examinations and the need for repeat surgery, and postoperative computed tomography scan results were evaluated to assess treatment success. RESULTS: The study involved 11 men and 26 women who underwent 50 Caldwell-Luc procedures. Caldwell-Luc procedure was performed bilaterally in 13 patients. The average number of prior endoscopic middle meatus antrostomies before Caldwell-Luc procedure was 2. Of all patients, 92% responded to surgical treatment as demonstrated by an endoscopic examination or computed tomography scan revealing a disease-free maxillary sinus. Repeat Caldwell-Luc procedure was required in 8.0% (n = 3) because of continued sinusitis. Two of the three cases with repeat Caldwell-Luc procedures demonstrated clinical improvement during follow-up. Average follow-up was 23.5 months. CONCLUSION: Caldwell-Luc procedure seems to be highly effective in the management of medically refractory chronic sinusitis after failed endoscopic middle meatus antrostomy. Caldwell-Luc procedure should remain in the otolaryngologist's surgical repertoire for these selected cases.

Vitamin C improves resistance but not conduit artery endothelial function in patients with chronic renal failure.

BACKGROUND: Chronic renal failure is associated with impaired endothelium-dependent vasodilation and accelerated atherogenesis. To examine whether endogenous reactive oxygen species (ROS) modify endothelial function in renal failure, we evaluated the effect of the antioxidant vitamin C on endothelium-dependent responses in both the conduit and resistance vasculature of subjects with severe renal impairment. METHODS: Endothelial function of the forearm resistance vasculature was assessed using plethysmography to measure the dilator response to intra-arterial acetylcholine (Ach) (25 to 100 nmol/min). Endothelial function of radial and brachial arteries was assessed using vascular ultrasound to measure the dilator response to flow during reactive hyperemia [flow-mediated dilatation (FMD)]. Studies were performed before and after administration of vitamin C by intra-arterial infusion (25 mg/min) in 33 predialysis patients or by intravenous infusion (3 g) in 17 hemodialysis patients. RESULTS: Parenteral administration of vitamin C resulted in a 100-fold increase (intra-arterial studies) and a 4.5-fold increase (intravenous studies) in serum antioxidant activity. Vitamin C administration increased the dilator response to ACh in resistance vessels (P = 0.01), but did not alter the dilator response to flow in conduit vessels of either dialysis (P = 0.3) or predialysis subjects (P = 0.8). In the presence of the nitric oxide (NO) synthase inhibitor NGmonomethyl-L-arginine (L-NMMA), there was no effect of vitamin C on resistance vessel endothelial function. In all cases the dilator response to the endothelium-independent dilators was unaffected by vitamin C. CONCLUSION: Acute administration of vitamin C reduces oxidant stress in renal failure and improves NO-mediated resistance vessel dilatation.