Humoral and hemodynamic responses after left ventricular assist device implantation and heart transplantation

Background: Left ventricular assist device (LVAD) implantation and heart transplantation (HTx) are established therapeutic approaches in end-stage heart failure. The postoperative humoral responses to the two treatments have not yet been compared.

Material and Methods: All patients were treated with inhaled nitric oxide (iNO) on weaning from cardiopulmonary bypass due to pulmonary hypertension. We investigated ANP, BNP, cGMP, ET-1, big ET and hemodynamics following LVAD implantation (15 patients, age 51±8 years) or HTx (10 patients, age 53±6 years) preoperatively, on cardiopulmonary bypass and postoperatively up to 72h after cessation of iNO.

Results: Preoperatively CI, PA pressures, PCWP, CVP and MAP were similar for both groups. Likewise ANP, BNP, cGMP, ET-1 and big ET were comparable prior to surgery. Seventy-two hours after weaning from iNO the administered epinephrine dose was higher in the HTx group (p=0.003) whereas CVP (p=0.04) and PVR (p=0.03) were lower. The following humoral parameters differed markedly; ANP (pg/ml) (preop: LVAD 98±124, HTx: 197±199 (p=0.14); 72h post iNO: LVAD 110±106, HTx: >640±0 (p=0.003) and cGMP (pg/ml) (preop: LVAD 4.4±5.8, HTx: 5.1±3.1 (p=0.35); 72h post iNO: LVAD 8.0±10.8, HTx: >26.2±25.8 (p=0.02).

Conclusions: Although the hemodynamic effects of both LVAD implantation and HTx in the treatment of end-stage heart failure are comparable, except for the effects on CVP and PVR, the humoral responses with respect to ANP and cGMP were strikingly different. These effects are independent of volume status, iNO and endothelins.