Extracorporeal Membrane Oxygenation Support in Refractory Cardiogenic Shock: Treatment Strategies and Analysis of Risk Factors

Two centrifugal pumps, the RotaFlow (Maquet, Jostra Medizintechnik AG, Hirrlingen, Germany) and Levitronix CentriMag (Levitronix LCC, Waltham, MA, USA), used in central or peripheral veno-arterial extracorporeal membrane oxygenation (ECMO) support systems have been investigated, in terms of double-center experience, as treatment for patients with refractory cardiogenic shock (CS). Between January 2006 and December 2012, 228 consecutive adult patients were supported on RotaFlow (n=213) or CentriMag (n=15) ECMO, at our institutions (155 men; age 58.3±10.5 years, range: 19-84 years). Indications for support were: failure to wean from cardiopulmonary bypass in the setting of postcardiotomy (n=118) and primary donor graft failure (n=37); postacute myocardial infarction CS (n=27); acute myocarditis (n=6); and CS on chronic heart failure (n=40). A peripheral ECMO setting was established in 126 (55.2%) patients while it was established centrally in 102 (44.7%). Overall mean support time was 10.9±9.7 days (range: 1-43 days). Eighty-four (36.8%) patients died on ECMO. Overall success rate, in terms of survival on ECMO (n=144), weaning from mechanical support (n=107; 46.9%), bridge to mid-long-term ventricular assist device (n=6; 2.6%), and bridge to heart transplantation (n=31; 13.5%), was 63.1%. One hundred twenty-two (53.5%) patients were successfully discharged. Stepwise logistic regression identified blood lactate level and MB isoenzyme of creatine kinase (CK-MB) relative index at 72 h after ECMO initiation, and number of packed red blood cells (PRBCs) transfused on ECMO as significant predictors of mortality on ECMO (P=0.010, odds ratio [OR]=2.94; 95% confidence interval [CI]=1.10-3.14; P=0.010, OR=2.82, 95% CI=1.014-3.721; and P=0.011, OR=2.69; 95% CI=1.06-4.16, respectively). Central ECMO population had significantly higher rate of continuous veno-venous hemofiltration need and bleeding requiring surgery events compared with the peripheral ECMO setting population. No significant differences were seen by comparing the RotaFlow and CentriMag populations in terms of device performance. At follow-up, persistent heart failure with left ventricle ejection fraction (LVEF)≤40% was a risk factor after hospital discharge. Patients with a poor hemodynamic status may benefit from rapid central or peripheral insertion of ECMO. The blood lactate level, CK-MB relative index, and PRBCs transfused should be strictly monitored during ECMO support. In addition, early ventricular assist device placement or urgent listing for heart transplant should be considered in patients with persistent impaired LVEF after ECMO.