Frequency and predictors of renal artery stenosis in hypertensive patients undergoing coronary angiography

Characteristics and predictors of low-grade renal artery stenosis in female patients with CKD

AIM

Renal artery stenosis (RAS) is an important cause of chronic kidney disease (CKD). The main purpose of this study was to explore the clinical characteristics and predictors of low-grade RAS in female patients with CKD.

METHODS

One hundred and five female CKD patients from Huadong Hospital affiliated with Fudan University who underwent 3 T non-contrast renal artery magnetic resonance angiography (MRA) were analyzed. Basic statistics methods were used in the study, such as independent-sample t test,non-parametric test, binary logistic regression analysis and ROC analysis.

RESULTS

In this cross-sectional study, there were 50 patients with RAS and 55 without RAS (47.6% versus 52.4%). Binary logistic regression analysis demonstrated that low-level ALB and lymphocyte count, high-level SP, BUN and NLR were independent risk factors for low-grade RAS in female patients with CKD. ROC analysis indicated that eGFR, FeNa and UBCR, ALB, lymphocyte count and NLR had the best predictive value for low-grade RAS, especially eGFR with a sensitivity of 65.50% and specificity of 72.00% and FeNa with a sensitivity of 71.10% and specificity of 72.20% and BUCR with a sensitivity of 71.10% and specificity of 68.10%.

CONCLUSION

In female patients with CKD, FeNa, eGFR, ALB, UBCR, lymphocyte count and NLR may be good predictors of low-grade RAS, especially eGFR, FeNa and BUCR.

Genetic and molecular aspects of hypertension

Until recently, significant advances in our understanding of the mechanisms of blood pressure regulation arose from studies of monogenic forms of hypertension and hypotension, which identified rare variants that primarily alter renal salt handling. Genome-wide association and exome sequencing studies over the past 6 years have resulted in an unparalleled burst of discovery in the genetics of blood pressure regulation and hypertension. More importantly, genome-wide association studies, while expanding the list of common genetic variants associated with blood pressure and hypertension, are also uncovering novel pathways of blood pressure regulation that augur a new era of novel drug development, repurposing, and stratification in the management of hypertension. In this review, we describe the current state of the art of the genetic and molecular basis of blood pressure and hypertension.

Renal Stenting for Kidney Salvage in the Management of Renal Artery Atherosclerotic Stenosis

We studied the usefulness of preoperative resistance index to select patients who will benefit most from renal stenting. Sixty-two patients underwent renal stenting. All had chronic renal insufficiency with serum creatinine values ranging from 1.5 to 2.5 mg/dL and blood urea nitrogen between 80 and 107 mg/dL. All treated renal artery stenosis were >70%. Reduction in blood pressure in the early stages was observed in 39 (62.9%) patients; 31 (79.4%) patients returned to preoperative values within 12 months. A progressive reduction in creatinine values and blood urea nitrogen was reached in 43 (69.4%) patients, 12 (19.4%) patients remained unchanged, and the remaining 7 (11.2%) patients worsened. The best improvement in renal function was obtained in patients with a resistance index of ≤0.75 A preoperative resistance index up to 0.75 could be used as an indicator to predict which candidates will have improved renal function after stenting.

Prevalence of and risk factors of renal artery stenosis in patients with resistant hypertension

Renal artery stenosis (RAS) is a common cause of secondary hypertension. Renal artery angiography is the gold standard for diagnosing RAS. The aim of this study is to report (1) the prevalence of RAS in patients with resistant hypertension and (2) the association of RAS with peripheral vascular disease (PVD) and diabetes mellitus (DM). We studied 285 consecutive patients (mean age: 72.5 years) with resistant hypertension (systolic blood pressure >140 mm Hg despite administration of at least 3 antihypertensive drugs) who underwent renal artery angiography at Baylor Heart and Vascular Hospital from January 2006 to December 2010. Sixty-nine cases of RAS were identified (incidence: 24.2%). The propensity-adjusted analysis (controlling for clinical and nonclinical risk factors) showed a strong and significant association between RAS and PVD (odds ratio 5.15, 95% confidence interval 2.68 to 9.89, p <0.0001). However, the association between RAS and DM, a previously defined risk factor for RAS, was not significant in this cohort (odds ratio 0.63, 95% confidence interval 0.34 to 1.19, p = 0.16). In conclusion, results from this study define the prevalence of RAS in patients with resistant hypertension. Patients with PVD were found to be 5 times more likely to experience RAS than patients without PVD, whereas DM did not confer any increased risk.

Results of the retrospective analysis of renal artery stenting for the salvage of renal function study

Renal artery stenting is expected to improve or stabilize renal function. However, the efficacy of renal artery stenting in severely reduced renal function is unclear. We evaluated 23 patients with class IV or V renal dysfunction who were treated for renal artery stenosis between 2004 and 2009. Improvement in renal function was found in 7 (30%) patients, all of whom were treated with distal protection device. Deterioration of renal function was found in 4 (17%) cases. In these 4 cases, distal protection device could not be used for anatomical reasons. The use of distal protection device was associated with significantly less renal deterioration after the procedure (P < .05, odds ratio 0.21 [confidence interval 0.09-0.50]). Renal artery stenting can stabilize or improve renal function in patients with severe renal dysfunction. Distal protection devices may be beneficial in patients who require renal artery stenting due to severely reduced renal function.