To the Editor:
EVAHEART (Sun Medical Technology Research Corp., Nagano, Japan) is a centrifugal continuous-flow left ventricular assist device (LVAD) with a hydraulically levitated impeller that has been used as bridge-to-transplantation in Japan since 2005.1 Motomura et al.2 presented preliminary results of the next generation EVAHEART 2 LVAD in bovines. Because of the “double-cuff tipless” cannula, they hypothesized that this device may prevent suction events that result in ventricular arrhythmias and wedge thrombus formation that results in pump thrombosis and systemic stroke.2
Our team recently demonstrated that optimal inflow cannula placement is crucial for cardiac unloading and optimized hemodynamics in HeartMate II and HVAD LVADs (Figure 1, A and B).3,4 Cannula placement directed toward the lateral wall may lead to insufficient blood removal from left ventricular (LV) cavity and failure of hemodynamic optimization probably, because of insufficient space around the “tip” to vacuum blood. Failure of hemodynamic optimization is associated with gastrointestinal bleeding,5 which remains a significant comorbidity even in the era of the HeartMate 3 LVAD.6 These trends may be adopted for all LVADs with “tip.”
The “double-cuff tipless” cannula of the EVAHEART 2 LVAD may have the advantage of adequate LV unloading irrespective of any cannula position because of sufficient space around the “tipless” cannula to vacuum blood. Theoretically, inflow malposition may be well tolerated with the EVAHEART 2 LVAD, and as a result, this new device may have an advantage in reducing both thrombotic and bleeding events over other types of LVADs.
Division of Cardiology
Department of Medicine
University of Chicago Medical Center
1. Saito S, Yamazaki K, Nishinaka T, et al; J-MACS Research Group: Post-approval study of a highly pulsed, low-shear-rate, continuous-flow, left ventricular assist device, EVAHEART: A Japanese multicenter study using J-MACS. J Heart Lung Transplant 2014.33: 599–608
2. Motomura T, Tuzun E, Yamazaki K, et al. Preclinical evaluation of the EVAHEART 2 centrifugal left ventricular assist device in bovines. ASAIO J 2018. DOI: 10.1097/MAT.0000000000000869.
3. Imamura T, Nguyen A, Chung B, et al. Association of inflow cannula position with left ventricular unloading and clinical outcomes in patients with HeartMate II left ventricular assist device. ASAIO J 2018. DOI: 10.1097/MAT.0000000000000823.
4. Imamura T, Adatya S, Chung B, et al. Cannula and pump positions are associated with left ventricular unloading and clinical outcome in patients with HeartWare left ventricular assist device. J Card Fail 2018.24: 159–166
5. Imamura T, Nguyen A, Kim G, et al. Optimal haemodynamics during left ventricular assist device support are associated with reduced haemocompatibility-related adverse events. Eur J Heart Fail 2018. DOI: 10.1002/ejhf.1372.
6. Mehra MR, Goldstein DJ, Uriel N, et al; MOMENTUM 3 Investigators: Two-year outcomes with a magnetically levitated cardiac pump in heart failure. N Engl J Med 2018.378: 1386–1395