Combination evaluation of preoperative risk indices predicts requirement of biventricular assist device

Background: Patients with biventricular assist device (BiVAD) placement have a poor prognosis, but preoperative risk factors for the necessity of BiVAD have not been fully elucidated. Methods and Results: Data from 79 patients who received left ventricular assist device (LVAD) between November 2002 and December 2011 were retrospectively reviewed. Overall, 9 patients (11.4%) required BiVAD, and the survival rate of BiVAD patients was significantly lower than that of LVAD patients (P<0.001). Multivariate analysis for BiVAD requirement showed left ventricular diastolic diameter (LVDd) <62mm (odds ratio [OR], 10.97; P=0.009) to be significantly associated with BiVAD requirement. Preoperative central venous pressure (CVP)/pulmonary capillary wedge pressure (PCWP) ratio >0.5 (OR, 13.09; P=0.028) was also significantly associated with BiVAD requirement. A new scoring system for predicting BiVAD requirement was created from the combination of CVP/PCWP ratio (>0.5), body surface area (<1.4m²), preoperative continuous hemodiafiltration use, B-type natriuretic peptide (>1,200pg/ml) and LVDd (<62mm), and this had a significantly larger area under the curve (0.909; P=0.003) than right ventricular stroke work index on receiver operating characteristic analysis. A score >20 using the new scoring method indicated significantly high probability of BiVAD requirement (OR, 16.00; P=0.019). Conclusions: The new scoring method, which includes CVP/PCWP ratio, is a novel risk stratification tool for BiVAD therapy.