'200 patient life years' is a fairly meaningless number unless (and I didn't listen to the audio, so I may have missed this step) you know HOW MANY were in the subject pool. If there were 200 patients in the research pool, living 1 year wouldn't mean much. If there were 50 in the pool, a 4 year survival rate would be more meaningful. This hasn't been in testing long enough for more than 5 or 6 years survival per patient (afaik), so it's not completely clear WHAT '200 patient life years' really means. I don't think you can extrapolate the results of 50 patients living 4 years each to suggest that the valve will, theoretically, last those implanted with the valve, for the rest of their lives (or, FWIW, 50 or more years).