title: Incidence and implications of idiopathic thrombocytopenia following transcatheter aortic valve replacement with the Edwards Sapien(©) valves: a single center experience.
abstract: OBJECTIVE
  To determine the incidence and etiology of thrombocytopenia following transcatheter Aortic valve replacement (TAVR).
  
  
  BACKGROUND
  the use of TAVR in the United States has grown rapidly. Anecdotally, thrombocytopenia following TAVR with the Sapien valves has been observed, though little is known about this phenomenon.
  
  
  METHODS
  All patients treated with TAVR using a Sapien valve or who underwent isolated balloon aortic valvuloplasty (BAV) at Brigham and Women's Hospital from October 2009 through November 2012 were analyzed. Post-procedure thrombocytopenia severity was stratified as none (>150,000 cells/μL), mild (100-150,000), and moderate to severe (<100,000). Summary statistics and simple comparisons were evaluated. Linear regression models were used to identify patient or procedural factors associated with platelet count nadir.
  
  
  RESULTS
  112 TAVR and 105 BAV patients were analyzed. Following TAVR the prevalence of thrombocytopenia was 69% and the incidence of new thrombocytopenia was 45% compared to 37% and 17% respectively following BAV (P < 0.01). Similar results were found across all strata of thrombocytopenia severity. Post-TAVR platelet nadirs were greater by 1,840 cells/μL for each 1% increase in STS score (P = 0.03) and 670 cells/μL greater for each 1 mmHg increase in pre-TAVR mean aortic stenosis gradient. Among TAVR patients, thrombocytopenia appears to spontaneously resolve an average of 8 days post-procedure. No differences in clinical outcomes based on thrombocytopenia severity were observed except for an increased use of blood products (P = 0.05).
  
  
  CONCLUSIONS
  Thrombocytopenia following TAVR with the Edwards' Sapien valves is a frequent but generally self-limited process. The etiology of this phenomenon is unknown.
authors.affiliation: Division of Cardiology, University of Washington, Seattle, WA.
authors.forename: James M
authors.initials: JM
authors.lastname: McCabe
authors.forename: Pei-Hsiu
authors.initials: PH
authors.lastname: Huang
authors.forename: Lauren A
authors.initials: LA
authors.lastname: Riedl
authors.forename: Srikanth R
authors.initials: SR
authors.lastname: Devireddy
authors.forename: Jennifer
authors.initials: J
authors.lastname: Grondell
authors.forename: Annie C
authors.initials: AC
authors.lastname: Connors
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Davidson
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Eisenhauer
authors.forename: Frederick G P
authors.initials: FG
authors.lastname: Welt
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000628:therapy*; D063126:Balloon Valvuloplasty; D001900:Boston / Q000453:epidemiology; D006328:Cardiac Catheterization / Q000009:adverse effects* / Q000295:instrumentation*; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000295:instrumentation*; D006801:Humans; D015994:Incidence; D008297:Male; D010976:Platelet Count; D011474:Prosthesis Design; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013921:Thrombocytopenia / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D013997:Time Factors; D016896:Treatment Outcome
keywords: complications adult cath/intervention; platelet function; valvular heart disease