Objectives: Review late mortality experience associated with surgical repair of regurgitant myxomatous mitral valves. Identify mortality associated with favorable and unfavorable characteristics for surgical mitral valve repair (MVR).
Methods: Overall mortality associated with MVR reported by several North American centers since 1980 is assessed. Mortality from additional studies on MVR associated with favorable and unfavorable preoperative characteristics is also determined. Standard mortality methodology is used and expectant mortality determined from the appropriate population life tables.
Results: Averaged (weighted for numbers of entrants) overall morality ratios (MR) for MVR from the Mayo Clinic and University of Toronto at 5, 10, and 15 years were 106%, 113% and 145%. Favorable characteristics included isolated posterior leaflet repairs (MR at 5, 10 and 15 years: 97%, 106% and 130%) and asymptomatic preoperative status, defined as New York Heart Association (NYHA) Functional Class I or II (MR at 5, 10 and 15 years: 69%, 50% and 93%). Unfavorable characteristics included isolated anterior mitral leaflet repairs (MR: 202%, 212% and 188%) and preoperative symptomatic NYHA Functional Class III or IV (MR: 142%, 130% and 127%). When reoperation was required, mild or moderate underlying myxomatous degeneration was favorable, usually enabling re-repair (MR at 12 years: 77%). Reoperation when severe myxomatous degeneration was present usually required prosthetic valve insertion (MR at 12 years: 187%). Coronary artery bypass grafting done at the time of MVR demonstrates an associated minimal increase in late mortality.
Conclusions: Surgical repair of myxomatous mitral valves produces durable long-term results with mild to modest overall increases in mortality. Favorable preoperative characteristics may be associated with near standard mortality risk.