"Long Term Survival of Patients Undergoing Mitral Valve Repair and Replacement: A Longitudinal Analysis of Medicare Fee-for-Service Beneficiaries" 
Circ April 8
http://circ.ahajournals.org/content/early/2013/04/08/CIRCULATIONAHA.113.002200.abstract 
"Conclusions—Mitral valve surgery in the Medicare population carries less risk than previously reported. Given the favorable outcomes of elderly patients undergoing mitral valve surgery, and especially mitral valve repair, an approach of earlier identification and surgical referral appears justified regardless of age."

"Transcatheter Aortic Valve Implantation for Pure Severe Native Aortic Valve Regurgitation" 
JACC April 2013 http://content.onlinejacc.org/article.aspx?articleid=1654982 
"Conclusions  This registry analysis demonstrates the feasibility and potential procedure difficulties when using TAVI for severe NAVR. Acceptable results may be achieved in carefully selected patients who are deemed too high risk for conventional surgery, but the possibility of requiring 2 valves and leaving residual aortic regurgitation remain important considerations.