Less Invasive Left Ventricular Unloading With Impella May Improve the Clinical Outcomes of Fulminant Myocarditis

Fulminant myocarditis (FM) requiring temporary mechanical circulatory support (t-MCS) has a high mortality rate. Peripheral veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and intra-aortic balloon pump (IABP) are sometimes insufficient to induce cardiac recovery. For patients with FM refractory to VA-ECMO with IABP, we have applied a biventricular assist device (BIVAD) or Impella to unload the left ventricle and to fully support the systemic circulation. In the last 10 years, 37 refractory FM patients histologically diagnosed with myocarditis and who did not recover with VA-ECMO were treated with BIVAD (n = 19) or Impella (n = 18). No significant difference was found between the Impella and BIVAD groups in preoperative findings other than serum creatinine level. Seventeen of 18 patients in the Impella group were successfully weaned from t-MCS in 9 (6-12) days. Conversely, the temporary BIVAD was removed in 21 (11-38) days in 10 of 19 patients. Six patients died while on temporary BIVAD because of multiple organ failure and cerebral bleeding, and three patients required conversion to implantable VAD. Compared with BIVAD, left ventricular unloading with Impella could be less invasive and could promote cardiac recovery in refractory FM patients. The Impella has the potential to provide effective temporary MCS for FM patients.