To the Editor:
The survival rate in patients with advanced heart failure has improved owing to the development of left ventricular assist devices (LVADs), which improves patients’ hemodynamics dramatically. However, our team recently demonstrated that half of LVAD patients had unoptimized hemodynamics.1
Optimization of hemodynamics following LVAD implantation seems to have various clinical implications. It is associated with reduced heart failure readmission as well as lower hemocompatibility-related adverse event rates.2 How can we achieve the hemodynamic optimization?
LVAD speed adjustment is attempted to optimize hemodynamics, but elevated central venous pressure is often more difficult to be optimized compared with other hemodynamic parameters.2 Unloading of left ventricle and increase in systemic circulation may be achieved by incremental LVAD speed. Unloading of left ventricle reduces afterload on right heart, whereas enhanced venous return increases preload on right heart.
Consistently, Kido et al.3 reported that diuretics therapy, which is an essential tool before LVAD implantation, was continued in more than half of patients during 2-year LVAD support. Inappropriately up-titrated loop diuretics may cause inappropriate activation of renin-angiotensin system and worsen renal function. Concomitant use of a newly developed vasopressin type-2 receptor antagonist, tolvaptan, may support these disadvantage of conventional diuretics by replacing some of them.4 There are few reports except for a case report written by Kimura et al.,5 who reported a usefulness of tolvaptan in a volume-overloaded LVAD patient. The clinical efficacy of long-term tolvaptan therapy in heart failure patients has been discussed thus far,6 whereas those for LVAD patients remains the next concern. Preservation of renal function would be of a great advantage particularly for the bridge to transplant candidates, considering renotoxicity of immunosuppressant following heart transplant.
Division of Cardiology
University of Chicago Medical Center Chicago, Illinois
1. Uriel N, Sayer G, Addetia K, et al. Hemodynamic ramp tests in patients with left ventricular assist devices. JACC Heart Fail 2016.4: 208–217.
2. Imamura T, Raikhelkar J, Sarswat N, et al. Optimal hemodynamics during LVAD support are associated with reduced readmission rate. J Heart Lung Transplant. 2018.37: 486–487.
3. Kido K, George B, Charnigo RJ, Macaulay TE, Brouse SD, Guglin M. Chronologic changes and correlates of loop diuretic dose in patients with left ventricular assist device. ASAIO J 2017.63: 774–780.
4. Imamura T. Aquaporin-2-guided tolvaptan therapy in patients with congestive heart failure accompanied by chronic kidney disease. Int Heart J 2014.55: 482–483.
5. Kimura M, Nawata K, Kinoshita O, et al. Successful treatment of intractable fluid retention using tolvaptan after treatment for postoperative mediastinitis in a patient with a left ventricular assist device. Int Heart J 2015.56: 574–577.
6. Imamura T, Kinugawa K. Update of acute and long-term tolvaptan therapy. J Cardiol 2019.73: 102–107.