Progression of atherosclerotic renovascular disease: a prospective population-based study
Presented at the Thirtieth Annual Meeting of The Southern Association for Vascular Surgery, Phoenix, Ariz, Jan 18 to 21, 2006.
Received 21 March 2006; accepted 17 July 2006. published online 19 September 2006.
Objective
Previous reports from select hypertensive patients suggest that atherosclerotic renovascular disease (RVD) is rapidly progressive and associated with a decline in kidney size and kidney function. This prospective, population-based study estimates the incidence of new RVD and progression of established RVD among elderly, free-living participants in the Cardiovascular Health Study (CHS).
Method
The CHS is a multicenter, longitudinal cohort study of cardiovascular risk factors, morbidity, and mortality among men and women aged >65 years old. From 1995 through 1996, 834 participants underwent renal duplex sonography (RDS) to define the presence or absence of significant RVD. Between 2002 and 2005, a second RDS study was performed in 119 participants (mean study interval, 8.0 ± 0.8 years). Significant RVD was defined as hemodynamically significant stenosis (renal artery peak systolic velocity [RA-PSV] exceeding 1.8 m/s) or renal artery occlusion. Prevalent RVD was significant RVD at the first RDS, and incident disease was defined as new significant RVD at the second RDS. Significant change of RVD was defined as a change in RA-PSV of greater than two times the standard deviation of expected change over time, regardless of hemodynamic significance or progression to renal artery occlusion.
Results
The second RDS study cohort included 119 CHS participants with 235 kidneys (35% men; mean age, 82.8 ± 3.4). On follow-up, no prevalent RVD (n = 13 kidneys; 6.0%) progressed to occlusion. Twenty-nine kidneys without RVD at the first RDS demonstrated significant change in PSV at the second RDS; including nine kidneys with new significant RVD (8 new stenoses; 1 new occlusion). Controlling for within-subject correlation, the overall estimated change in RVD among all 235 kidneys was 14.0% (95% confidence interval [CI], 9.2% to 21.4%), with progression to significant RVD in 4.0% (95% CI, 1.9% to 8.2%). Longitudinal increase in diastolic blood pressure and decrease in renal length were significantly associated with progression to new (ie, incident) significant RVD but not prevalent RVD.
Conclusions
This is the first prospective, population-based estimate of incident RVD and progression of prevalent RVD among free-living elderly Americans. In contrast to previous reports among select hypertensive patients, CHS participants with a low rate of clinical hypertension demonstrated a significant change of RVD in only 14.0% of kidneys on follow-up of 8 years (annualized rate, 1.3% per year). Progression to significant RVD was observed in only 4.0% (annualized rate, 0.5% per year), and no prevalent RVD progressed to occlusion.
aDivision of Surgical Sciences, Section on Vascular and Endovascular Surgery, Winston-Salem, North Carolina
bDepartment of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North Carolina
Reprint requests: Kimberley J. Hansen, MD, Professor of Surgery, Head of the Section on Vascular and Endovascular Surgery, Division of Surgical Sciences, Wake Forest University School of Medicine, Medical Center Blvd, Winston-Salem, NC 27157-1095
Supported in part by a grant from the National Institute of Diabetes and Digestive and Kidney Diseases 1R01DK47414 and contracts N01-HC-85079 through N01-HC-85086, N01-HC-35129, and N01 HC-15103 from the National Heart, Lung, and Blood Institute and the Wake Forest University General Clinical Research Center (GCRC) M01-RR07122.
ABSTRACT