Use of renin-angiotensin inhibitors in people with renal artery stenosis

Abstract

Background and objectives: People with atherosclerotic renal artery stenosis may benefit from renin-angiotensin inhibitors, angiotensin-converting enzyme inhibitors, and angiotensin-receptor blockers, but little is known about the factors associated with their use.

Design, setting, participants, & measurements: The Cardiovascular Outcomes in Renal Atherosclerotic Lesions study (ClinicalTrials.gov identified: NCT00081731) is a prospective, international, multicenter clinical trial that randomly assigned participants with atherosclerotic renal artery stenosis who received optimal medical therapy to stenting versus no stenting from May 2005 through January 2010. At baseline, medication information was available from 853 of 931 randomly assigned participants. Kidney function was measured by serum creatinine-based eGFR at a core laboratory.

Results: Before randomization, renin-angiotensin inhibitors were used in 419 (49%) of the 853 participants. Renin-angiotensin inhibitor use was lower in those with CKD (eGFR<60 ml/min per 1.73 m(2)) (58% versus 68%; P=0.004) and higher in individuals with diabetes (41% versus 27%; P<0.001). Presence of bilateral renal artery stenosis or congestive heart failure was not associated with renin-angiotensin inhibitor use. Although therapy with renin-angiotensin inhibitors varied by study site, differences in rates of use were not related to the characteristics of the site participants. Participants receiving a renin-angiotensin inhibitor had lower systolic BP (mean ± SD, 148 ± 23 versus 152 ± 23 mmHg; P=0.003) and more often had BP at goal (30% versus 22%; P=0.01).

Conclusions: Kidney function and diabetes were associated with renin-angiotensin inhibitor use. However, these or other clinical characteristics did not explain variability among study sites. Patients with renal artery stenosis who received renin-angiotensin inhibitor treatment had lower BP and were more likely to be at treatment goal.

Keywords: ACE inhibitors; blood pressure; renal artery stenosis.

Copyright © 2014 by the American Society of Nephrology.

Figures

Figure 1.

Associations of patient characteristics with angiotensin-converting enzyme inhibitor or angiotensin-receptor blocker (ACEI/ARB) use. Demographic characteristics include male sex, Hispanic/Latino ethnicity, and enrollment in the United States. Risk factors and comorbid conditions include CKD, moderate to severe CKD, diabetes, and angina. Shaded circles indicate odds ratio estimate, with brackets indicating 95% confidence intervals for renin-angiotensin inhibitor use in logarithmic scale.

Figure 2.

Variation in ACEI/ARB use by site. Odds ratios (ORs) and 95% confidence intervals (95% CIs) for site use of ACEI/ARB grouped by low (≤25%), intermediate (>25 to ≤75%), and high (>75%) proportional use, indicated in red, blue, and green, respectively. The non-ACEI/ARB group was the comparator reference at each site. Dark squares indicate OR estimates, with lines indicating 95% CIs for renin-angiotensin inhibitor use in logarithmic scale. Size of square indicates number of patients enrolled at the respective site. Sites outside of the United States are indicated by an asterisk.

Figure 3.

Associations of medications with ACEI/ARB use. Nonantihypertensives included lipid-lowering agents, antiplatelet agents, and nitrates. Antihypertensives included diuretics, calcium-channel blockers, β-blockers, aldosterone antagonists, α-blockers, αβ-blockers, and vasodilators. Black circles indicate OR estimate, with brackets indicating 95% CIs for renin-angiotensin inhibitor use in logarithmic scale. One class of medication, renin inhibitors, was not included because of low frequency of use.