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.