title: Revascularisation of renal artery stenosis as a therapy for heart failure: an observational cohort study.
abstract: BACKGROUND
  Heart failure contributes to 5% of all hospital admissions, and mortality is more than 50% at 4 years. 54% of patients with a left ventricular ejection fraction of less than 40% have renal artery stenosis. The potential benefit of revascularisation for heart failure is not established. We aimed to compare clinical outcomes for renal artery revascularisation with medical therapy for renal artery stenosis associated with heart failure as the first step towards validating revascularisation as a therapeutic option in heart failure.
  
  
  METHODS
  In a prospective, longitudinal observational study at a single UK nephrology centre, we recruited patients with atherosclerotic renal artery stenosis (>50% as judged by CT, MR, or direct angiography). Endpoints were all-cause mortality and hospital admission for heart failure. Survival analyses were performed with Cox proportional hazard model adjusted for age, estimated glomerular filtration rate (eGFR), and cardiovascular comorbidities. Ethics approval was granted by South Manchester Research Ethics Committe.
  
  
  RESULTS
  611 patients (152 [25%] with and 459 [75%] without heart failure) were recruited. Mean age was 70 years (SD 9), 348 (57%) were men, 183 (30%) had diabetes, and mean eGFR was 33 mL/min per 1·73 m(2) (SD 19). Patients with and without heart failure were similar with to sex, diabetes, and eGFR. 367 participants (60%) died over a follow-up of a mean of 4·3 years (SD 3·6). 87 patients without heart failure (19%) underwent revascularisation compared with 47 with heart failure (31%). The adjusted hazard ratio (HR) for death in heart failure compared with no heart failure was 1·9 (95% CI 1·5-2·5, p<0·0001). For patients without heart failure, the adjusted HR for death in revascularisation compared with receiving medical therapy was 0·8 (0·5-1·1, p=0·16). For heart failure, the HR was 0·6 (0·3-0·9, p=0·01). The HR for hospital admission for heart failure in revascularised patients was 0·2 (0·0-1·1, p=0·06).
  
  
  CONCLUSIONS
  Revascularisation of renal artery stenosis in heart failure is associated with a substantial reduction in all-cause mortality and hospital admission, although such observational data might be complicated by hidden confounders. These findings are encouraging for the development of a randomised trial of renal artery revascularisation versus medical therapy in heart failure, and suggest that investigation for renal artery stenosis should be considered more frequently in heart failure clinics.
  
  
  BACKGROUND
  None.
authors: Institute of Population Health, University of Manchester, Manchester, UK. Electronic address: darrengreen@doctors.org.uk.
authors: Darren
authors: D
authors: Green
authors: Institute of Population Health, University of Manchester, Manchester, UK.
authors: James P
authors: JP
authors: Ritchie
authors: Department of Renal Medicine, Salford Royal Hospital, Salford, UK.
authors: Constantina
authors: C
authors: Chrysochou
authors: Department of Renal Medicine, Salford Royal Hospital, Salford, UK.
authors: Philip A
authors: PA
authors: Kalra