Risk factor analysis of long-term support with left ventricular assist system

This study was designed to elucidate the key factors for successful long-term support with a left ventricular assist system (LVAS) in the situation where heart transplantation is rarely available.

From 1992 to 2008, 106 patients underwent 121 LVAS implantations at Osaka University Hospital (Toyobo: 77; Novacor: 18; HeartMate: 14; Jarvik2000: 8; EvaHeart: 2; DuraHeart: 2). Risk factors for infection were early on the former implanted period (odds ratio (OR) 3.30), Toyobo (OR 2.25), mechanical right heart support (OR 2.30) and cardiopulmonary bypass time (OR 1.01). Left atrium as the inflow site was the risk factor for cerebrovascular events (OR 2.84). Older age (OR 1.04) and mechanical right heart support (OR 4.70) were risk factors for mortality. Risk factors for requiring mechanical right heart support were preoperative extracorporeal membranous oxygenation support (OR 5.641), serum total bilirubin (OR 1.11) and serum creatinine (OR 2.46). On the basis of the risk analysis for mortality, patients were divided into 2 subgroups (low and high risk) and the respective cumulative survival at 1 year after LVAS implantation was 75.2% and 25.0%.

Appropriate selection of device, patient and the timing of implantation and less invasive operation are important for successful long-term LVAS support.