Improved survival in patients with acute myocarditis using external pulsatile mechanical ventricular assistance.

BACKGROUND: Acute myocarditis remains a disease with a variable clinical course, from full ventricular recovery to complete heart failure; to date, few cases have been reported that describe the efficacy of temporary mechanical ventricular assistance for its treatment.

METHODS: We evaluated the voluntary world registry with the use of an external pulsatile ventricular assist device (the ABIOMED BVS 5000 [BVS]) for acute myocarditis to determine the impact of mechanical ventricular assistance on outcome. Variables analyzed included patient demographics, serum chemistries, and overall hemodynamics prior to BVS, while on BVS support, and after BVS explanation. Postoperative parameters included re-operation, bleeding, respiratory failure, renal failure, and infections, neurologic, or embolic events.

RESULTS: Eighteen patients in the ABIOMED world registry underwent BVS implantation for myocarditis; 11 (61.1%) had complete pre-operative and hemodynamic data for analysis. Patients were supported for 13.2 +/- 17.0 days, after which time 7 (63.6%) patients survived to explanation of the device and 2 (18.2%) underwent transplantation. Elevated admission serum chemistries (blood ureanitrogen [BUN], creatinine, transaminases) and hemodynamics (central venous pressure [CVP], mean pulmonary arterial pressure [PAP], pulmonary capillary wedge pressure [PCW], cardiac index [CI], all normalized during the period of device support. Estimated ejection fractions in the 7 explanted patients ranged between 50 to 60% at routine evaluation 3 years after device removal.

CONCLUSIONS: Temporary mechanical ventricular assistance represents an efficacious therapy for acute myocarditis in patients with hemodynamic decompensation despite maximal medical therapy. Failure to achieve full ventricular recovery while on device support still allows for other surgical alternatives, including implantation of a long-term implantable ventricular assist device, or cardiac transplantation.