Neurohormonal changes after implantation of a left ventricular assist system

In patients with left ventricular dysfunction, neurohormonal levels are valuable indicators of the severity of heart disease and prognosis. For patients with severe left ventricular dysfunction, left ventricular assist systems (LVAS) are effective as short-term bridges to heart transplantation and are currently being investigated for long-term use. Unknown, however, are the effects of mechanical unloading of the left ventricle on neurohormone levels during the initial weeks after LVAS implantation, and whether these changes are similar to the neurohormonal level decreases observed after cardiac transplantation. This study was undertaken to determine the effect of LVAS support on plasma norepinephrine (PNE) levels during the initial weeks after device implantation. The PNE levels in five consecutive patients with left ventricular dysfunction were measured within 1 week after LVAS implantation and every week thereafter for 5 weeks. Significant decreases in PNE levels were observed after 3 weeks of LVAS support. After 5 weeks of LVAS support, PNE levels had decreased to near normal. For patients with severe left ventricular dysfunction, the improved prognosis after LVAS support may be due in part to the normalization of neurohormonal levels. The findings indicate that PNE levels may be of value in determining whether a patient can be weaned from LVAS support.