Nine-month results of the REFORM study : A prospective, single-arm, multicenter clinical study of the safety and effectiveness of the formula™ balloon-expandable stent for treatment of renal

Percutaneous revascularization of the renal arteries improves patency in atherosclerotic renovascular disease, yet evidence of a clinical benefit is limited. In a randomized, unblinded trial, we assigned 806 patients with atherosclerotic renovascular disease either to undergo revascularization in addition to receiving medical therapy or to receive medical therapy alone. The primary outcome was renal function, as measured by the reciprocal of the serum creatinine level (a measure that has a linear relationship with creatinine clearance). Secondary outcomes were blood pressure, the time to renal and major cardiovascular events, and mortality. The median follow-up was 34 months. During a 5-year period, the rate of progression of renal impairment (as shown by the slope of the reciprocal of the serum creatinine level) was -0.07x10(-3) liters per micromole per year in the revascularization group, as compared with -0.13x10(-3) liters per micromole per year in the medical-therapy group, a difference favoring revascularization of 0.06x10(-3) liters per micromole per year (95% confidence interval [CI], -0.002 to 0.13; P=0.06). Over the same time, the mean serum creatinine level was 1.6 micromol per liter (95% CI, -8.4 to 5.2 [0.02 mg per deciliter; 95% CI, -0.10 to 0.06]) lower in the revascularization group than in the medical-therapy group. There was no significant between-group difference in systolic blood pressure; the decrease in diastolic blood pressure was smaller in the revascularization group than in the medical-therapy group. The two study groups had similar rates of renal events (hazard ratio in the revascularization group, 0.97; 95% CI, 0.67 to 1.40; P=0.88), major cardiovascular events (hazard ratio, 0.94; 95% CI, 0.75 to 1.19; P=0.61), and death (hazard ratio, 0.90; 95% CI, 0.69 to 1.18; P=0.46). Serious complications associated with revascularization occurred in 23 patients, including 2 deaths and 3 amputations of toes or limbs. We found substantial risks but no evidence of a worthwhile clinical benefit from revascularization in patients with atherosclerotic renovascular disease. (Current Controlled Trials number, ISRCTN59586944.) 2009 Massachusetts Medical Society

Renal artery stenosis (RAS) is a relatively uncommon but potentially reversible cause of renal failure. In a previous report, we demonstrated that the presence of RAS is independently associated with mortality in a group of patients undergoing coronary angiography. Our current study expands on this cohort, investigating the effect of the severity of RAS on all-cause mortality. A total of 3987 patients underwent abdominal aortography immediately following coronary angiography. For the purpose of survival analysis, significant RAS was defined as > or =75% narrowing in the luminal diameter. Significant RAS was present in 4.8% of patients studied and was bilateral in 0.8%. Factors associated with the presence of RAS included female gender, older age, hypertension, congestive heart failure, elevated serum creatinine, and congestive heart failure. The four-year unadjusted survivals for patients with and without significant RAS were 57 and 89%, respectively (P or =95% stenosis was 70%, 68%, and 48%, respectively. In addition, bilateral disease was associated with four-year survival of 47% as compared with 59% for patients with unilateral disease (P < 0.001). The impact of RAS on survival remained robust regardless of the manner of treatment of coronary artery disease [that is, medical, percutaneous transluminal coronary angioplasty (PTCA), or coronary artery bypass graft (CABG)]. In this patient population, the presence of RAS is a strong independent predictor of mortality. Increasing severity of RAS has an incremental effect on survival probability.

Although atherosclerotic renovascular disease is increasingly recognized in chronic kidney disease, few national level studies have examined its clinical epidemiology. Claims data from a 5% random sample of the United States Medicare population were used to select patients without atherosclerotic renovascular disease in the 2 years preceding December 31, 1999 (N= 1,085,250), followed until December 31, 2001. The incidence of atherosclerotic renovascular disease was 3.7 per 1000 patient-years. Major antecedent associations [P 1.5] included chronic kidney disease (adjusted HR 2.54), hypertension (2.42), peripheral vascular disease (2.00), and atherosclerotic heart disease (1.70). Adverse event rates after incident atherosclerotic renovascular disease greatly exceeded those in the general population (P < 0.0001): atherosclerotic heart disease, 303.9 per 1000 patient-years (vs. 73.5 in the general population); peripheral vascular disease, 258.6 (vs. 52.2); congestive heart failure, 194.5 (vs. 56.3); cerebrovascular accident or transient ischemic attack, 175.5 (vs. 52.9); death, 166.3 (vs. 63.3); and renal replacement therapy, 28.8 (vs. 1.3). Among atherosclerotic renovascular disease patients, 16.2% underwent a renal revascularization procedure, percutaneously in 96%. Revascularization was not associated with renal replacement therapy, congestive heart failure, or death but was associated with atherosclerotic heart disease (adjusted HR 1.42) (P= 0.004) and peripheral vascular disease (adjusted HR 1.38) (P= 0.002). Atherosclerotic renovascular disease is strongly associated with cardiovascular disease, both past and future. Absolute cardiovascular risk exceeds that of renal replacement therapy. Renal revascularization is used selectively and shows inconsistent associations with cardiovascular outcomes, renal replacement therapy, and death.