Abstract
Background Prognoses and long-term cardiac function of patients with fulminant myocarditis have not been fully elucidated. Therefore, we clarified the prognoses and long-term cardiac function according to required percutaneous mechanical circulatory support and histological findings among patients with fulminant myocarditis. Methods and Results We conducted a multicenter retrospective medical record review of 216 patients with fulminant myocarditis requiring percutaneous mechanical circulatory support. Sixty-one patients were treated with intra-aortic balloon pump or Impella alone, and 155 patients received veno-arterial extracorporeal membrane oxygenation and were treated with or without intra-aortic balloon pump or Impella. Histologically, 107 patients had lymphocytic myocarditis; 34, eosinophilic myocarditis; and 4, giant cell myocarditis. Freedom from composite end point (death, durable left ventricular assist device implantation, and heart transplantation) was 66% at 90 days, 62% at 1 year, and 57% at 6 years. Veno-arterial extracorporeal membrane oxygenation use was associated with poor prognosis in the multivariable analysis (hazard ratio [HR], 5.27; 95% CI, 1.60-17.36). The eosinophilic myocarditis subgroup showed better prognosis (HR, 0.28; 95% CI, 0.10-0.80) compared with the lymphocytic myocarditis subgroup but not in the multivariable analysis. Ventricular tachycardia/ventricular fibrillation rhythm at admission, high C-reactive protein level, and no endomyocardial biopsy were also associated with poor prognosis. The left ventricular ejection fraction at 1 year was ≤50% in 16% of patients and was lower in patients with eosinophilic myocarditis (median: 57.9% [48.8-65.0%]) than in those with lymphocytic myocarditis (65.0% [58.6-68.7%]) (P=0.036). Conclusions Patients with fulminant myocarditis who received veno-arterial extracorporeal membrane oxygenation had a poor prognosis. Long-term cardiac function was impaired in some patients, especially those with eosinophilic myocarditis.