Contemporary outcomes of continuous-flow biventricular assist devices

Abstract

Background: Significant right ventricular failure (RVF) complicating left ventricular assist device (LVAD) placement has been reported at 10-30%. Although primarily indicated for left ventricular failure, ventricular assist devices (VADs) have become utilized in a biventricular setup to combat right ventricular failure (RVF) following LVAD implantation. With the advent of continuous-flow LVADs (CF-LVADs) superseding their pulsatile predecessors, the shift towards CF-biventricular assist devices (CF-BiVADs) come with the prospect of improved outcomes over previous pulsatile BiVADs. We aim to review the literature and determine the outcomes of CF-BiVAD recipients.Methods: A systematic review was performed to determine the outcomes of CF-BiVADs. Pre-operative demographics and device configuration data was collected. Primary outcomes evaluated were short-term survival, long-term survival, duration of support, and survival to transplant. Secondary outcomes evaluated included intensive care unit (ICU) and hospital length of stay (ICU-LOS and HLOS, respectively), pump thrombosis, pump exchange. Median and interquartile range was reported where appropriate. A major limitation was the likely overlap of cohorts across publications, which may have contributed to some selection bias.Results: Of 1,282 screened, 12 publications were evaluated. Sample size ranged from 4 to 93 CF-BiVAD recipients, and follow-up ranged from 6 to 24 months. Mean age ranged from 34 to 52 years old. Forty-five percent of CF-BiVADs had right atrial (RA-) inflow cannulation, with the remaining being right ventricular (RV). Thirty-day survival was a median of 90% (IQR 82-97.8%) and 12-month survival was a median of 58.5% (IQR 47.5-62%). Where reported, rate of pump thrombosis (predominantly the right VAD) was a median of 31% (IQR 14-36%), although pump exchange was only 9% (IQR 1.5-12.5%).Conclusions: RVF post-LVAD implantation is a high morbidity and mortality complication. There is no on-label continuous-flow RVAD currently available. Thus, the modifications of LVADs for right ventricular support to combat pump thrombosis has resulted in various techniques. BiVAD recipients are predominantly transplant candidates, and complications of pump thrombosis and driveline infection whilst on wait-list are of great consequence. This study demonstrates the need for an on-label CF-BiVAD.

Cardiac Surgery in Advanced Heart Failure

“…In the case of unlikely recovery of RV dysfunction after LV LT-MCS implantation, a biventricular setup of continuousflow VADs has been utilized. This therapeutic approach is complicated by a high rate of pump thrombosis [72]; therefore, implantation of a total artificial heart (THA) remains a valid option. Candidates for TAH are most often considered when HTx candidates suffer from acute irreversible biventricular failure at high risk for imminent death (INTERMACS class 1 or 2) and for whom a suitable donor is not available.…”

Prediction, prevention, and management of right ventricular failure after left ventricular assist device implantation: A comprehensive review

“…As an alternative, dual HM3 support has been demonstrated, but necessitates either partial cardiotomy (304)(305)(306) or right atrial configuration (307,308). Comprehensive studies are lacking, as reported survival rates with HM3 in an RVAD configuration widely ranges from 30% at 3 months to 92% at 18 months (298,(306)(307)(308).…”

“…Most published cases of durable intracorporeal RVAD using bilateral continuous-flow VADs underwent upfront BIVAD and not staged implantation after RVF, which has been associated with worse outcomes ( 297 ). However, patients receiving durable BIVAD support were more acutely ill than those receiving isolated LVAD ( 298 ). When performed simultaneously, durable BIVAD is as effective as total artificial heart regarding survival until transplantation.…”

Evaluation of centrifugal blood pump performances for biventricular support in the virtual simulation model

“…Some groups have reported biventricular support by HVAD or HM3 in the clinical setting, but there is a lack of in vitro hemodynamic evaluation of the HM3 used as an RVAD for RHF 8–13 . Most notably, in their review of continuous‐flow BVAD outcomes in 2021, Farag et al identified eight studies that used an HVAD for RVAD and three studies that used the HM3 for RVAD 14 . Although the HVAD is not available in the market, comparison with successful CF technologies such as the HVAD and HM3 represent value to study clinical characteristics of CF pumps used as BVAD configurations.…”

“…[8][9][10][11][12][13] Most notably, in their review of continuous-flow BVAD outcomes in 2021, Farag et al identified eight studies that used an HVAD for RVAD and three studies that used the HM3 for RVAD. 14 Although the HVAD is not available in the market, comparison with successful CF technologies such as the HVAD and HM3 represent value to study clinical characteristics of CF pumps used as BVAD configurations.…”