title: 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 artery stenosis.
abstract: OBJECTIVE
  To evaluate the 9-month safety and effectiveness outcomes of the Formula™ balloon-expandable renal stent (Cook Medical, Bloomington, IN) for the treatment of atherosclerotic renal artery stenosis (RAS) following suboptimal angioplasty.
  
  
  BACKGROUND
  Atherosclerotic RAS can cause hypertension and ischemic nephropathy. When clinically indicated, an interventional approach with renal angioplasty and stent implantation is the preferred method for revascularization of atherosclerotic renal artery stenoses.
  
  
  METHODS
  The REFORM study is a prospective, multicenter, single-arm study of stent implantation following suboptimal PTRA using the Formula stent. One hundred patients with atherosclerotic ostial renal artery lesions =18 mm in length with a >50% residual stenosis following PTA were enrolled. The primary endpoint was 9-month primary patency.
  
  
  RESULTS
  The 9-month primary patency rate was 91.7%. The 9-month major adverse event rate was 2.2%. Mean systolic blood pressure was significantly decreased at follow-up (from 150 ± 21 mm Hg at baseline to 141 ± 21 mm Hg at 9 months; P = 0.003). Mean serum creatinine (SCr) level and mean estimated glomerular filtration rate (eGFR) were not significantly different at 9 months. A clinically meaningful improvement in renal function (i.e., =25% increase in eGFR or =0.5 mg/dl decrease in SCr) was observed in 9% of patients at 1 month and 12% of patients at 9 months. A clinically meaningful decline in renal function (i.e., =25% decrease in eGFR or =0.5 mg/dl increase in SCr) was observed in only 3% of patients at 1 month and 7% of patients at 9 months.
  
  
  CONCLUSIONS
  The Formula stent was safe and effective in treating atherosclerotic RAS following suboptimal angioplasty.
authors.affiliation: Department of Cardiology, Swedish Medical Center, Seattle, Washington, USA. robert.bersin@swedish.org
authors.forename: Robert M
authors.initials: RM
authors.lastname: Bersin
authors.forename: Gary
authors.initials: G
authors.lastname: Ansel
authors.forename: Anthony
authors.initials: A
authors.lastname: Rizzo
authors.forename: H
authors.initials: H
authors.lastname: Bob Smouse
authors.forename: Shantanu
authors.initials: S
authors.lastname: Sinha
authors.forename: Ravish
authors.initials: R
authors.lastname: Sachar
authors.forename: Rajesh
authors.initials: R
authors.lastname: Dave
authors.forename: Barry S
authors.initials: BS
authors.lastname: Weinstock
authors.forename: Robert
authors.initials: R
authors.lastname: Feldman
authors.forename: Gary S
authors.initials: GS
authors.lastname: Roubin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000800:Angioplasty, Balloon / Q000009:adverse effects / Q000295:instrumentation*; D050197:Atherosclerosis / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011474:Prosthesis Design; D012078:Renal Artery Obstruction / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States; D014654:Vascular Patency
chemical_list: D015415:Biomarkers; D003404:Creatinine