Clinical experience with ventricular assist systems in Japan

In Japan, five types of ventricular assist system, including the government-approved National Cardiovascular Center type and the Tokyo University type, were applied to 202 patients as of September 30, 1991. Adult-sized ventricular assist systems were used in 194 patients and a pediatric one in 8. The major primary diagnosis was ischemic heart disease (52.5%). Sixty-three patients in cardiogenic shock with acute myocardial infarction were treated using a ventricular assist system, and the results were fairly good. The predominant indication was failure to be weaned from cardiopulmonary bypass (72.8%), and there was no case of bridging to heart transplantation. Left ventricular assist was performed in most patients (85.1%). The duration of ventricular assist system application ranged from 1 hour to 70 days, and the mean duration was 6.8 +/- 9.6 days. Duration of circulatory support had no relation to the results, and the longest support in survivors was 25 days. The weaning rate was 50.0%, and the survival rate was 26.2%. Main causes of death were heart failure, including unrecoverable heart failure, and multiple organ failure. It should be kept in mind that the decision to use a ventricular assist system should be made quickly, before major organs, including the heart itself, are irreversibly damaged.