Brain natriuretic peptides in atherosclerotic renal artery stenosis and effects of renal angioplasty.

BACKGROUND: We hypothesized that plasma levels of brain natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP) would be elevated, and adiponectin concentrations reduced, in patients with atherosclerotic renal artery stenosis (ARAS) and that BNPs might be used to identify patients who would benefit from percutaneous transluminal renal angioplasty (PTRA). METHODS: Data were collected before renal angiography in 91 patients with hypertension and suspected ARAS (significant ARAS; n=47, and non-RAS; n=44) and in 20 healthy controls (C). In ARAS patients analyses were repeated four weeks after PTRA. RESULTS: Ambulatory systolic blood pressure (ASBP) was significantly elevated in the ARAS group vs. both C and non-RAS groups. Baseline plasma BNP and NT-proBNP levels were significantly elevated, and adiponectin concentrations reduced, in the ARAS group vs. C but not vs. the non-RAS group. One month after PTRA, ASBP was reduced vs. baseline (149±16 to 139±15 mm p<0.01). Brain natriuretic peptides were not significantly affected by PTRA. CONCLUSIONS: Patients with ARAS showed elevated of BNP and NT-proBNP concentrations, and reduced levels of adiponectin, compared to healthy controls but not vs. hypertensive individuals without RAS. Our data do no support the use of BNP analyses in the identification of ARAS patients who will have a beneficial blood pressure response to PTRA.

Lipoprotein abnormalities in patients with atherosclerotic renovascular disease.

BACKGROUND: Patients with atherosclerotic renovascular disease (ARVD) have a high risk of cardiovascular death. The primary aim was to characterize abnormalities in apolipoprotein (Apo)-defined lipoprotein (Lp) subclasses in patients with ARVD. METHODS: Baseline measurements were performed on 42 patients with ARVD 4 weeks after renal angioplasty (PTRA). All patients were on statin treatment. Twenty age-matched healthy subjects without medications served as controls. Subsequently, patients were randomized to treatment with either candesartan (n = 21), or antihypertensive treatment without inhibitors of the renin-angiotensin-aldosterone system (n = 21) and followed for 11 months. RESULTS: At baseline, ApoC-III (12.7 ± 4.6 vs. 8.8 ± 2.6 (SD) mg/dl, p < 0.05), LpB:C:E (13.3 ± 5.4 vs. 8.4 ± 4.3 mg/dl, p < 0.05), and the sum of ApoC-III-containing lipoproteins, i.e. LpB:C + LpB:C:E + LpA-II:B:C:D:E (46 ± 15 vs. 37 ± 8 mg/dl, p < 0.05), were significantly elevated in ARVD patients versus healthy controls. Multiple regression analyses showed that only plasma renin activity was independently associated with ApoC-III levels at baseline (p < 0.05, r = 0.74). Treatment with candesartan did not correct abnormalities. CONCLUSIONS: Patients with ARVD treated with statins have an atherogenic lipoprotein profile characterized by elevated levels of ApoC-III-containing, triglyceride-rich lipoproteins that could accelerate atherosclerotic disease.

Accuracy of colour duplex sonography for the diagnosis of renal artery stenosis.

OBJECTIVE: To examine the diagnostic value of novel velocimetric colour duplex sonography indices in the screening of renal artery stenosis (RAS). METHODS: We performed a retrospective analysis of all consecutively studied patients at our centre with suspected RAS, and a colour duplex sonography carried out at less than 4 months (mean 34 days) before renal angiography during a 6-year period (2002-2007). A significant RAS was defined as an at least 60% stenosis on angiography or a transstenotic mean arterial pressure gradient of at least 10 mmHg or both. RESULTS: In a total of 169 patients, 111 stenotic and 206 nonstenotic kidneys were examined. The sensitivity and specificity for acceleration of blood flow in early systole (ACCmax) were 85 and 75%, respectively, and for the acceleration index (ACCmax/peak systolic velocity, AImax) 83 and 79%, respectively. Corresponding values in patients with estimated glomerular filtration rate of less than 30 ml/min/1.73 m2 were 90 and 73% (for ACCmax) and 74 and 88% (for AImax). In addition, the transstenotic mean arterial pressure gradient showed a significant, though weak, negative correlation to ACCmax (r = -0.26, P = 0.02) and AImax (r = -0.29, P = 0.01) in stenotic kidneys. CONCLUSION: ACCmax and AImax provide similar, good diagnostic accuracy in the detection of a haemodynamically significant RAS, even in patients with markedly reduced glomerular filtration rate. Presumably, the lack of superiority of the novel index AImax could be explained by a highly homogenous methodological approach in the present single-centre study.