Transplant candidate's clinical status rather than right ventricular function defines need for univentricular versus biventricular support

Abstract

We have studied our experience since 1988 with 31 patients who required a mechanical circulatory bridge to transplantation and also had biventricular failure (mean right ventricular ejection fraction 11.8%) to better define the need for biventricular or total artificial heart support versus univentricular support. Clinical factors including preoperative inotropic need, fever without detectable infection, diffuse radiographic pulmonary edema, postoperative blood transfusion, and right ventricular wall thickness were compared with hemodynamic parameters including cardiac index, right ventricular ejection fraction, central venous pressure, mean pulmonary arterial pressure, and total pulmonary resistance for ability to predict need for mechanical or high-dose inotropic support for the right ventricle. Patients were grouped according to need for right ventricular support after left ventricular–assist device implantation: none (group A, 14) inotropic drugs (group B 1, 7), and right ventricle mechanical support (group B 2, 10). There were no differences in preimplantation hemodynamic variables. Groups B 1 and B 2 had significantly lower mixed venous oxygen saturation (39.2% vs 52.5% in group A; p < 0.001), greater level of inotropic need ( p < 0.02), greater impairment of mental status, and lower ratio of right ventricular ejection fraction to inotropic need (0.37 vs 0.56 for group A; p < 0.02) before left ventricular–assist device implantation. A significant discriminator between groups B 1 and B 2 was the presence of a fever without infection within 10 days of left ventricular–assist device implantation (43% in group B 1 vs 70% in group B 2). Group B 2 had more patients with preimplantation pulmonary edema seen on chest radiography and a greater requirement for postoperative blood transfusion (5 units of cells in group B 1 vs 14.8 units in group B 2). Right ventricular wall thickness at left ventricular–assist device explantation was 0.83 cm in group B 2 vs 0.44 cm in group B 1 ( p < 0.05). Transplantation rates after bridging were 100% in group A, 71% in group B 1, and 40% in group B 2. Clinical factors that reflect preimplantation degree of illness and perioperative factors that result in impairment of pulmonary blood flow or reduced perfusion of the right ventricle after left ventricular–assist device implantation are now considered to be more predictive of the need for additional right ventricular support than preimplantation measures of right ventricular function or hemodynamic variables. (J T HORAC C ARDIOVASC S URG 1996;111:773-83)