EFFECT OF THE IMPLANTABLE LEFT-VENTRICULAR ASSIST DEVICE ON NEUROENDOCRINE ACTIVATION IN HEART-FAILURE

Background The HeartMate left ventricular assist device has been succe ssfully used as a bridge to cardiac transplantation. Because many pati ents exhibit marked clinical improve ment in their heart failure after HeartMate implantation, we studied the physiological effect of this d evice on the neurohormonal axis.Methods and Results In 13 patients; aw aiting transplant (mean cardiac index, 1.7+/-0.3 L . min(-1). m(-2)) w ho underwent HeartMate implantation, venous atrial natriuretic peptide , epinephrine, norepinephrine, plasma renin activity, angiotensin, and arginine vasopressin were measured immediately before insertion and a t explant/transplantation. Mean time to explant was 86+/-40 days. All patients were taken off inotropic medications within 1 month. Mean car diac index on support before explant was 3.1+/-0.9 L . min(-1). m(-2). Plasma renin activity decreased from 57+/-56 ng . mL(-1). h(-1) at ba seline (before insertion) to 3+/-3 ng . mL(-1). h(-1) at explant (mean percent change, 92%; P<.001). Angiotensin II level decreased from 237 +/-398 U/L at baseline to 14+/-14 U/L at explant (mean percent change, 73%; P<.001). Plasma epinephrine level fell from 6800+/-1323 pg/mL at baseline to 46+/-46 pg/mL at explant (mean percent change, 86%; P<.00 1). Norepinephrine level decreased from 2953+/-1457 pg/mL at baseline to 518+/-290 pg/mL at explant (mean percent change, 79%; P<.001). Atri al natriuretic peptide fell from baseline values of 227+/-196 to 168+/ -40 pg/mL at explant (mean percent change, -49%; P=.519); and arginine vasopressin level decreased from 6+/-6 pg/mL, at baseline to 0.8+/-0. 5 pg/mL (mean percent change, 69%; P=.002). Conclusions We provide dat a supporting that the neurohormonal axis markedly improves after Heart Mate implantation, providing biochemical confirmation of the improveme nt in hemodynamic status.