Discussion
Post-infarct PMR is a fatal complication that leads to CGS and PLE due
to severe MR. 1 Previous studies have emphasized the
importance of prompt diagnosis and an aggressive surgical approach
without delay to improve the outcome of post-infarct PMR.3-5 However, the SHOCK Trial Registry demonstrated
that approximately half of patients with CGS due to severe post-AMI MR
could not undergo surgery for unstable hemodynamics awaiting surgery.2 Therefore, early preoperative stabilization using an
appropriate MCS is warranted.
IABP is the most common MCS for CGS, and approximately 40–60% of
patients with PMR undergo IABP preoperatively. However, the operative
mortality of 13–40% was not satisfactory. 4, 5Although Hryniewicz et al. demonstrated that V/AECMO potentially
improves short- and long-term survival in patients with refractory CGS,8 V/AECMO is not adequate to unload the LV and PLE
because of increased afterload. Impella is a reasonable MCS for
unloading the LV directly, reducing the severity of MR and increasing
forward flow. The usefulness of Impella for CGS due to PMR or severe
ischemic MR has been reported. 6, 7 However, Impella
does not help hypoxia due to PLE. Several studies demonstrated that
ECPELLA for CGS had a significantly lower mortality rate and higher rate
of subsequent therapy or recovery compared with V/AECMO alone.9-10 These reports highlighted ECPELLA’s ability to
facilitate forward-flow increase, improve systolic and diastolic
pulmonary pressure, decrease vasoactive medication requirement, reduce
the area of myocardial ischemia, and improve PLE and oxygenation.9-10 These effects are suitable for stabilizing the
preoperative conditions in patients with PMR. Therefore, we recommend
early ECPELLA as a bridge to surgery because early MCS for AMI-induced
CGS potentially improves short-term outcomes. 5, 11Although ECPELLA may have the potential risk of sucking the ruptured
papillary muscle, we didn’t confirm these findings in our cases.
Postoperative hemodynamic and respiratory management is important for
achieving satisfactory surgical outcomes in patients with PMR. Previous
studies have demonstrated that 70% of patients require postoperative
IABP, 30% require postoperative ECMO, and 50% require prolonged
respiratory assist. 3-5 Successful postoperative
management using Impella 5.0 in a patient with PMR has been reported.12 Despite a few knacks to master and pitfalls to
overcome, as shown in Figure 5, we believe that ECPELLA should be
maintained during surgery with the ImPL in surgical mode and a low ECMO
flow (500–600 mL/min) for postoperative management. Ideally, ECPELLA
should be removed during surgery if CPB can be weaned off without
ECPELLA, because ECPELLA is associated with greater hemolysis, vascular
complications, and a higher need for transfusion. 9-10
In conclusion, ECPELLA is a useful and feasible MCS as a bridge to
surgery in patients with CGS due to post-infarct PMR. MVs can be
performed safely using ECPELLA.