Postoperative Tolvaptan Use in Left Ventricular Assist Device Implantation Patients: The TOLVAD Study

• Published in: The Journal of heart and lung transplantation Vol. 40; no. 4; p. S446
• Main Authors: Belkin, M.N., Imamura, T., Kanelidis, A., Henry, M., Fujino, T., Kagan, V., Meehan, K., Okray, J., Creighton, S., LaBuhn, C., Song, T., Ota, T., Jeevanandam, V., Nguyen, A.B., Chung, B.B., Smith, B.A., Kalantari, S., Grinstein, J., Sarswat, N., Pinney, S.P., Sayer, G., Kim, G., Uriel, N.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.04.2021
• ISSN: 1053-2498; 1557-3117
• DOI: 10.1016/j.healun.2021.01.1243

Tolvaptan, a selective vasopressin type-2 antagonist, has been shown to increase serum sodium (Na) and urine output in hyponatremic left ventricular assist device (LVAD) patients in retrospective studies. We aimed to assess the efficacy of tolvaptan in this population in a prospective, randomized study. We conducted a prospective, randomized, non-blinded study of LVAD recipients with post-operative hyponatremia (Na < 135 mEq/L). Eligible patients were randomized to receive tolvaptan 15 mg daily in addition to standard care vs standard care alone. The primary outcome was change in Na level and renal function, measured by estimated glomerular filtration rate (eGFR), from the first post-operative day of hyponatremia to discharge. A total of 33 patients were consented, 30 of whom developed post-operative hyponatremia. Two were excluded due to new onset renal failure requiring hemodialysis prior to development of hyponatremia. Of 28 eligible patients (21% women, 54% Black, 32% ischemic cardiomyopathy) 15 were randomized to tolvaptan (TLV), and 13 were randomized to standard care alone (No-TLV). Patients in TLV had a significant increase in Na from randomization to discharge, 133 (IQR 132-134) to 135 mEq/L (IQR 134-137), p=0.018, while those in No-TLV did not have a significant change in Na, 133 (IQR 132-134) to 134 mEq/L (IQR 132-136), p=0.15 (1A). There were no significant differences in renal function in either arm of the study: eGFR 76 (IQR 51-99) to 80 mL/min/1.73m2 (IQR 66-90), p=0.97 in TLV versus eGFR 78 (IQR 56-115) to 115 mL/min/1.73m2 (IQR 56-120), p=0.13 in No-TLV (1B). Patients in TLV had significantly more urine output than those in No-TLV during their first 24 hours of hyponatremia (3294 vs 2155 mL, p=0.043) and during last 24 hours of hyponatremia prior to sodium correction (4177 vs 2739 mL, p<0.001) (1C). Tolvaptan improves Na in hyponatremic post-operative LVAD patients when compared to those not receiving tolvaptan without adversely impacting renal function.