3、Ischemic Mitral Regurgitation-Repair vs Replacement
IMR is a result of adverse LV remodeling after myocardial injury,
including enlargement of the LV chamber and mitral annulus, apical and
lateral displacement of the papillary muscles, leaflet tethering and
decreased closing forces. These processes can lead to malcoaptation of
the leaflets and varying degrees of MR , which can fluctuate dynamically
with heart rhythm, volume status, afterload, and residual
ischemia[57]. The leaflets are normal, and the
pathological changes appear in the myocardium rather than in the valve
itself. Therefore, the treatment of functional IMR is quite different
from that of primary degenerative MR[58]. Practice
guidelines recommend that for patients with severe IMR who experience
restrictive symptoms despite the best available medical treatment and
possibly cardiac resynchronization, MV repair or chordal-sparing
replacement should be considered[59,60]. However,
these guidelines do not specify whether to do the
MV repair or replacement, because
there is no clear evidence on which of these intervention is better.
Clinical studies have shown that MV repair is associated with lower
perioperative mortality[61-63], but replacement
provides better long-term correction and lower risk of recurrence (an
important consideration is that recurrence of mitral regurgitation may
lead to atrial fibrillation, heart failure and readmission) (Table
1 )[64-68]. But some studies suggest the early
mortality of the repair group is higher than that of the replacement
group[69,70]. And some other studies have
demonstrated that survival after combined surgery is mainly affected by
factors related to the patient’s condition during the operation, but not
by the MV repair or replacement (Table
1 )[71,72]. This perceived trade off between
reduced operative morbidity and mortality with repair and better long
term IMR correction with replacement has produced significant variation
in surgical practice for this high-prevalence
condition[58].