Predictors of hospital length of stay after implantation of a left ventricular assist device: an analysis of the INTERMACS registry

Abstract

Background: Few studies have reported on hospital length of stay (LOS) after left ventricular assist device (LVAD) implantation. The purpose of this study was to determine pre- and peri-operative predictors of hospital LOS after LVAD implantation.

Methods: We analyzed adult primary continuous-flow LVAD patients implanted between June 23, 2006 and December 31, 2010 at 105 institutions from the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS). Retrospective analyses included measures of central tendency, frequencies, correlations and stepwise multivariable regression modeling (p ≤ 0.05). Independent variables included demographic characteristics, pre-implant clinical and behavioral variables and concomitant surgery.

Results: Characteristics of the patients (n = 2,200) included: mean age 54.6 ± 12.6 years; 79% male; 69% white; 57% INTERMACS Profile 1 or 2; 37% diabetic; 21% with history of coronary artery bypass graft (CABG); 7% with history of valve surgery; and 37% with concomitant surgery. Median hospital LOS (implant to discharge) was 20 days. Significant predictors of an increased hospital LOS included demographic characteristics (older age and non-white), pre-implant clinical variables (history of CABG or valve surgery, diabetes, ascites, INTERMACS Profiles 1 and 2, low albumin, high blood urea nitrogen, high right atrial pressure) and concomitant surgery, explaining 12% variance (F = 22.65, p<0.001).

Conclusions: Demographic characteristics, pre-implant variables and concomitant surgery partially explained hospital LOS after continuous-flow LVAD implant. These variables have implications regarding selection of patients for mechanical circulatory support.

Keywords: continuous flow; heart failure; length of stay; mechanical circulatory support; ventricular assist device.