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A review of the available information was performed.A single center retrospective review of its 58 redo mitral valve replacement cases between january 2005 and december 2014.As all of these are redo's, all of them present problems necessitating the re-operation.It is a specialized subset of records.However, we do not have a perspective on how this group fits into the center's overall implant record nor its significance to the general mvr population.Nor are we able to establish how many of the cases are related to the on-x valve other than that it was "the most commonly used." nevertheless, the review does have some characteristics of note.The patient demographics show a male:female ratio of 1:3.They also show that the average inr was 1.96 (aha/acc recommends inr of 2.5-3.5 with daily 70-100 mg aspirin for mechanical mitral valves [nishimura 2014)) and compliance prior to surgery was reported in 71% of the patients, which means 29% were non-compliant.31 patients (54%) were diagnosed with valve thrombosis.As the authors noted, the average age was 32 ± 15.81 years, which is younger than the world literature would suggest.The leading cause underlying mitral valve replacement was rheumatic fever.It is also noted that the mean duration between first and redo surgery was 8.8 years and that none of the redo's reported were due to a lack of valve durability.Finally, the mortality rate was considered negligible (although 2 patients died postoperatively).All of these adverse event observations are expected [instructions for use (ifu)], although the frequency of occurrence is difficult to correlate with rest-of-the-world experience.Consequently, we cannot make any judgment on on-x valve performance relative to expectations as we have no quantitative comparators upon which to base any conclusions.The following adverse events are listed in the ifu.As noted, any number of the following adverse events could lead to reoperation and explantation.See excerpt from the ifu below.Http://www.Onxlti.Com/ifu/hv/, ¿5.Potential adverse events - adverse events potentially associated with the use of prosthetic heart valves (in alphabetical order) include, but are not limited to: angina, cardiac arrhythmia, endocarditis, heart failure, hemolysis, hemolytic anemia, hemorrhage, myocardial infarction, prosthesis leaflet entrapment (impingement), prosthesis nonstructural dysfunction, prosthesis pannus, prosthesis perivalvular leak, prosthesis regurgitation, prosthesis structural dysfunction, prosthesis thrombosis, stroke, thromboembolism.¿ it is possible that these complications could lead to: reoperation, explantation, permanent disability, death.The article does not identify additional hazards or modify the probability and severity of existing hazards.With the data presented, we cannot say what, or how much, if any, contribution the on-x valves had to the events necessitating reoperations.Root cause for this information is unknown.No further action is warranted at this time.
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