Mechanical circulatory support as a bridge to transplantation: current status of total artificial heart in 1989 and determinants of survival.

Since April 1986, 40 total artificial hearts (TAH) were implanted as a bridge to transplantation in our institution. In an attempt to identify factors affecting survival of TAH recipients we reviewed our experience over 1000 days of mechanical support. There was no postoperative bleeding requiring surgery nor were there any clinical episodes of thromboembolic complications. Over a total functioning period greater than 3 years there were no mechanical failures in the driving system but one artificial ventricle had to be replaced because of mechanical dysfunction. Infections and multiple organ failure were the primary causes of morbidity and mortality during mechanical support. When the patients who underwent staged transplantation (no. 17) were compared with those who died during mechanical support (no. 23) there were no differences in TAH driving mode or hemodynamic variables between the groups. Although preoperative pulmonary, hepatic and renal functions were found to be similar between the groups, there were significant differences in the early evolution (3 days) of hepatic and renal functions following TAH implant (p less than 0.01). Urinary output was found to be the earliest variable discriminating recovery and survival (p less than 0.01). Finally, univariate analysis indicated age (less than 40 vs greater than 40 years) and modality of cardiac decompensation (acute vs chronic) as the most important factors affecting survival after TAH implantation. Since young patients (less than 40 years of age) with acute decompensation were successfully transplanted in 82% of cases while 100% of older patients with chronic decompensation died before or after transplantation, TAH should be advised in young patients with acute or chronic heart failure and in selected older candidates with recent, acute cardiac failure.