Reduction Of Platelet Count After Aortic Valve Replacement (avr): Comparison Of Three Bioprostheses
Giacomo Ravenni, MD1, Michele Celiento, MD1, Gabriele Ferrari, MD1, Aldo Milano, MD,PhD2, Giovanni Scioti, MD1, Stefano Pratali, MD1, Gaetano Minzioni, MD1, Uberto Bortolotti, MD1.
Concerns have been raised regarding postoperative decrease in platelet count (PC) after AVR with biological prosthesis. Thus, a retrospective analysis was conducted on patients after AVR with 3 different bioprostheses (Medtronic Mosaic, MOS, Sorin Freedom SOLO, SFS, Sorin Mitroflow, MIT) to assess and compare postoperative reduction in PC and evaluate its clinical impact.
3 groups of patients (25 each) undergoing AVR with a biological prosthesis were compared. The three groups were similar in terms of preoperative characteristics, particularly mean PC showed no significant difference. PC was obtained on postoperative day I, III and V and at discharge. Thrombocytopenia was considered as PC (plt/mmc) <150.000 and being considered severe < 30.000.
No significant difference was observed in duration of extracorporeal circulation and cross clamping.Mean postoperative PC for SFS group was 99.000 ± 27.000 on day I, 67.000 ± 9.000 on day III, 78.000 ± 54.000 on day V and 96.000 ± 32.000 at discharge; for MOS group it was 154.000 ± 56.000 on day I, 154.000 ± 54.000 on day III, 161.000 ± 85.000 on day V and 228.000 ± 95.000 at discharge; for MIT group it was 126.000 ± 37.000 on day I, 113.000 ± 38.000 on day III, 130.000 ± 46.000 on day V and 170.000 ± 50.000 at discharge. Severe thrombocytopenia was never observed, while significant decrease in PC occurred in SFS group when compared to MOS (on day I, III, and V and at discharge, p<0.001) and to MIT (on day III, V and at discharge, p<0.005). Multivariate analysis showed SFS (<0.001) and patient age (<0.01) as incremental risk factors for thrombocytopenia. No significant difference was observed in terms of postoperative thromboembolic or hemorrhagic events, transfusion requirement, duration of hospitalization and hospital mortality.
Reduction in platelet count was observed in all groups in postoperative day I being more evident after AVR with SFS, while complete normalization at discharge occurred only with MOS. Thrombocytopenia after biological AVR was not associated to any major postoperative complication and did not require any additional treatment.
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