Incidence and implications of idiopathic thrombocytopenia following transcatheter aortic valve replacement with the Edwards Sapien(©) valves: a single center experience.

OBJECTIVES: 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.