Severe thrombocytopenia and its clinical impact after implant of the stentless Freedom Solo bioprosthesis.

BACKGROUND

This single-center study analyzed the occurrence of severe thrombocytopenia and its clinical effect after concomitant and isolated aortic valve replacement (AVR) with the stentless Freedom Solo (FS) prosthetic valve (Sorin Group, Saluggia, Italy).

METHODS

Between October 2009 and February 2012, 151 consecutive patients underwent AVR with a FS, either isolated (lone-FS group) or concomitant with another procedure (all-FS group). These groups were compared with 152 consecutive patients implanted with a stented Edwards Lifesciences Perimount (EP) bioprosthesis (Edwards Lifesciences, Irvine, CA). Primary end point was the incidence of severe thrombocytopenia (platelet count < 50 × 10(9)/L). Secondary end points were clinical outcomes, administered transfusions (red blood cells, thrombocytes, frozen plasma), and adverse events. Rinsing the FS before implantation with saline solution was also evaluated.

RESULTS

Platelet counts were significantly lower in the all-FS and lone-FS groups than in the EP group during the first 5 days (p < 0.001). Average nadir was 102 ± 50 in lone-FS group and 130 ± 35 in lone-EP group (p < 0.001). Independent predictors for severe thrombocytopenia were FS, body surface area, and preoperative platelet count. No significant difference was found in transfusions or adverse events. Intensive care unit stay was slightly increased in the lone-FS group (p = 0.04). Rinsing the FS did not prevent thrombocytopenia.

CONCLUSIONS

AVR with FS was associated with severe thrombocytopenia during the first postoperative days. Besides a slightly longer hospitalization in the intensive care unit in the FS group, the clinical outcome did not differ significantly, indicating thrombocytopenia was a transient and self-recovering phenomenon, not affecting clinical outcome. Rinsing the FS did not prevent thrombocytopenia.