Renal Frame Count and Renal Blush GradeQuantitative Measures That Predict the Success of Renal Stenting in Hypertensive Patients With Renal Artery Stenosis
Ehtisham Mahmud, MD, FACC*,
Thomas W.R. Smith, MD,
Vachaspathi Palakodeti, MD, FACC,
Owais Zaidi, MD,
Lawrence Ang, BS,
C. Robinson Mitchell, MD,
Nayab Zafar, MD,
Guilherme Bromberg-Marin, MD,
Shahin Keramati, MD, FACC,
Sotirios Tsimikas, MD, FACC
Division of Cardiovascular Medicine, School of Medicine, University of California, San Diego, San Diego, California.
* Reprint requests and correspondence: Dr. Ehtisham Mahmud, Cardiovascular Catheterization Laboratories, University of California, San Diego Medical Center, 200 West Arbor Drive, San Diego, California 92103-8784. (Email: emahmud{at}ucsd.edu).
Objectives: This study sought to identify angiographic parameters of favorable clinical response to renal artery stenting.
Background: Stenting improves blood pressure (BP) control in patients with renal artery stenosis (RAS), but markers predicting a favorable clinical response are limited.
Methods: Renal perfusion was quantified in hypertensive patients (BP 140/90 mm Hg) without RAS by determining renal frame count (RFC) (angiographic frames [30 frames/s] for contrast to reach distal renal parenchyma after initial renal artery opacification) and renal blush grade (RBG) (0: none, 1: minimal, 2: normal, 3: hyperemic parenchymal blush). It was hypothesized that stenting unilateral RAS in hypertensive patients would result in decreased RFC and increased RBG, which might predict BP reduction.
Results: The RFC in 17 consecutive hypertensive patients without RAS (control group) (64.4 ± 14.2 years, 12 male, 22 kidneys) was 20.1 ± 5.4, whereas RBG was 2.33 ± 0.66. In 24 consecutive hypertensive patients with unilateral RAS (study group) (72.7 ± 11.3 years, 8 male), reduced RFC (26.6 ± 9.1 to 21.4 ± 6.7, p < 0.001) and increased RBG (1.63 ± 0.71 to 2.13 ± 0.85, p = 0.03) were observed after renal stenting. At 6 months, reduced BP (systolic BP 150.6 ± 15.6 mm Hg to 128.6 ± 15.5 mm Hg, p < 0.001; diastolic BP 77.2 ± 15.6 mm Hg to 68.3 ± 10.4 mm Hg, p = 0.022) without change in number of hypertensive medications was observed. Clinical responders (systolic BP reduction >15 mm Hg) had a greater decrease in RFC (7.7 ± 4.6 vs. 1.7 ± 5.1, p = 0.009) and 78.6% of patients with >4 RFC decrease were responders (p = 0.024).
Conclusions: This study shows that quantitative indices of renal perfusion (RFC and RBG) are impaired in patients with RAS and improve after stenting, and that RFC reduction is associated with BP reduction.
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Abbreviations and Acronyms
| | BP = blood pressure | | RA = renal artery/arteries | | RAS = renal artery stenosis | | RBG = renal blush grade | | RFC = renal frame count |
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P. L. Whitlow
Atherosclerotic Renal Artery Stenosis: Where's Waldo?
J. Am. Coll. Cardiol. Intv.,
June 1, 2008;
1(3):
293 - 294.
[Full Text]
[PDF]
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