Choice of mechanical support for fulminant myocarditis: ECMO vs. VAD?

Fulminant myocarditis, VAD, ECMO

The article by Grinda and colleagues in the December 2004 issue of the European Journal of Cardiothoracic Surgery regarding the experience of ventricular assist device (VAD) support on fulminant myocarditis (FM) [1] deserves our respect and we congratulate their excellent results.

From 1995 to 2001, we used extracorporeal membrane oxygenation (ECMO) in our institute as first-line mechanical support to treat 15 patients of FM with shock, including 5 under external cardio-pulmonary resuscitation (CPR) and 10 with high-degree atrio-ventricular block. Our results revealed 93.3% (14/15) in successful weaning rate and 73.3% (11/15) in discharge survival rate [2,3]. The average ECMO support time was 129±50h (127±83h for the survivors). As compared with the article [1] and another study regarding ABIOMED use for FM [2], ECMO group had lower morbidity rate than VAD group: mechanical related thrombo-embolism was 6.7% in ECMO group [3] and 40–27.3% in VAD group [1,2]; re-exploration for hemostasis was 20% in ECMO group [3] and 45.5% in VAD group [2].

We would like to mention the following points for the mechanical support for FM. First, since FM tends to recover within 2 weeks [4], ECMO is an appropriate option for this relatively short duration. ECMO is easier to wean off than VAD, and ECMO can be converted to VAD at any time if necessary. Secondly, biventricular involvement is common in FM (over 70% with right heart involvement as reported [4]), therefore ECMO might be a suitable choice for FM in critical condition because the degree of right heart failure cannot be predicted accurately. Therefore, we agree the authors' protocol of using BiVAD. Third, the support duration to recovery was shorter in ECMO group than in VAD group (5.5±3.0 days in ECMO group [3] vs. 10.2±6.1 days for BiVAD group [1] and 10.0±5.3 days for ABIOMED group [2]). This indicated that the theoretically incomplete decompression of left ventricle (LV) in ECMO group did not negatively influence the recovery of LV in FM. Fourth, daily troponin level was found as a good indicator for myocardial recovery in weaning of ECMO [3], but it cannot be applied in VAD group.

The final solution of the best choice of mechanical support for FM still awaits further evidence-based studies.