title: The prevalence, incidence, progression, and risks of aortic valve sclerosis: a systematic review and meta-analysis.
abstract: OBJECTIVE
  The aim of this study was to comprehensively review the epidemiology of aortic sclerosis (ASc) and its association with cardiovascular events.
  
  
  BACKGROUND
  ASc, which is defined as thickening or calcification of the aortic valve without significant obstruction of blood flow, is a common finding on cardiac imaging.
  
  
  METHODS
  We searched MEDLINE and EMBASE from inception to April 2013 for studies describing the epidemiology of ASc and performed a meta-analysis of the risk of adverse events using a random effects model.
  
  
  RESULTS
  Twenty-two studies were identified from the systematic review. The prevalence of ASc increased in proportion to the average age of study participants, ranging from 9% in a study in which the mean age was 54 years to 42% in a study in which the mean age was 81 years. In total, 1.8% to 1.9% of participants with ASc had progression to clinical aortic stenosis per year. There was a 68% increased risk of coronary events in subjects with ASc (hazard ratio [HR]: 1.68; 95% confidence interval [CI]: 1.31 to 2.15), a 27% increased risk of stroke (HR: 1.27; 95% CI: 1.01 to 1.60), a 69% increased risk of cardiovascular mortality (HR: 1.69; 95% CI: 1.32 to 2.15), and a 36% increased risk of all-cause mortality (HR: 1.36; 95% CI: 1.17 to 1.59).
  
  
  CONCLUSIONS
  ASc is a common finding that is more prevalent with older age. Despite low rates of progression to ASc, there is an independent increase in morbidity and mortality associated with the condition.
authors.affiliation: Department of Cardiology, Oxford University Hospitals, Oxford, United Kingdom; Department of Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand. Electronic address: sean.coffey@ouh.nhs.uk.
authors.forename: Sean
authors.initials: S
authors.lastname: Coffey
authors.affiliation: Department of Preventive and Social Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
authors.forename: Brian
authors.initials: B
authors.lastname: Cox
authors.affiliation: Department of Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
authors.forename: Michael J A
authors.initials: MJ
authors.lastname: Williams
mesh_terms: D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D018450:Disease Progression; D014943:Global Health; D006339:Heart Rate; D006801:Humans; D015994:Incidence; D015995:Prevalence; D011379:Prognosis; D012307:Risk Factors
keywords: aortic valve sclerosis; aortic valve stenosis; epidemiology; heart valve diseases; meta-analysis; systematic review