Predicting right ventricular failure in the modern, continuous flow left ventricular assist device era

Strategies for Mechanical Right Ventricular Support during Left Ventricular Assist Device Implant

BACKGROUND

Refractory right ventricular failure at the time of left ventricular assist device implantation requires treatment with supplemental mechanical circulatory support. However, the optimal strategy for support remains unknown.

METHODS

All patients undergoing first time durable left ventricular assist device implantation with a contemporary device were selected from the national Society of Thoracic Surgeons Database (2011-2019). Patients requiring right ventricular assist device (RVAD) or venoarterial extracorporeal membrane oxygenation (VA-ECMO) were included in the analysis. Patients were stratified by RVAD or VA-ECMO and by timing of placement (intraoperative vs. postoperative).

RESULTS

18,423 left ventricular assist device implants were identified, of which 940 (5.1%) required RVAD (n=750) or VA-ECMO (n=190) support. Patients receiving an RVAD more frequently had preoperative inotrope requirement (76% vs. 62%, p<0.01) and severe tricuspid regurgitation (20% vs. 13%, p<0.01). RVAD patients experienced lower rates of postoperative renal failure (40% vs. 51%, p=0.02) and limb ischemia (4% vs. 13%, p<0.01), as well as significantly less operative mortality (41% vs. 54%, p<0.01). After risk-adjustment with propensity score analysis, support with VA-ECMO was associated with a higher risk of mortality (Risk Ratio 1.46 [1.21-1.77], p<0.01) compared to patients receiving an RVAD. Importantly, institution of right ventricular support postoperatively was associated with higher mortality (1.43, p<0.01) compared to intraoperative initiation.

CONCLUSIONS

Patients with severe right ventricular failure in the setting of durable left ventricular assist device implantation may benefit from the use of RVAD over VA-ECMO. Regardless of the type of support, initiation at the index operation was associated with improved outcomes.

A multi-institutional retrospective analysis on impact of RV acute mechanical support timing after LVAD implantation on 1-year mortality and predictors of RV acute mechanical support weaning

BACKGROUND

There is little insight into which patients can be weaned off right ventricular (RV) acute mechanical circulatory support (AMCS) after left ventricular assist device (LVAD) implantation. We hypothesize that concomitant RV AMCS insertion instead of postoperative implantation will improve 1-year survival and increase the likelihood of RV AMCS weaning.

METHODS

A multicenter retrospective database of 826 consecutive patients who received a HeartMate II or HVAD between January 2007 and December 2016 was analyzed. We identified 91 patients who had early RV AMCS on index admission. Cox proportional-hazards model was constructed to identify predictors of 1-year mortality post-RV AMCS implantation and competing risk modeling identified RV AMCS weaning predictors.

RESULTS

There were 91 of 826 patients (11%) who required RV AMCS after CF-LVAD implantation with 51 (56%) receiving a concomitant RV AMCS and 40 (44%) implanted with a postoperative RV AMCS during their ICU stay; 48 (53%) patients were weaned from RV AMCS support. Concomitant RV AMCS with CF-LVAD insertion was associated with lower mortality (HR 0.45 [95% CI 0.26-0.80], p = 0.01) in multivariable model (which included age, BMI, angiotensin-converting enzyme inhibitor use, and heart transplantation as a time-varying covariate). In the multivariate competing risk analysis, a TPG < 12 (SHR 2.19 [95% CI 1.02-4.70], p = 0.04) and concomitant RV AMCS insertion (SHR 3.35 [95% CI 1.73-6.48], p < 0.001) were associated with a successful wean.

CONCLUSIONS

In patients with RVF after LVAD implantation, concomitant RV AMCS insertion at the time of LVAD was associated with improved 1-year survival and increased chances of RV support weaning compared to postoperative insertion.

Contemporary Mechanical Circulatory Support with Continuous Flow Biventricular Assist Devices: A Systematic Review

As the incidence of heart failure increases, so too has that of biventricular failure. While transplantation remains the gold standard therapy for end-stage heart failure, the limited organ supply has increased the need for durable mechanical circulatory support. We therefore sought to conduct a systematic review of continuous flow ventricular assist devices in a biventricular configuration (CF-BiVAD). An electronic search of PubMed and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases was performed using the keyword "BIVAD". Studies were reviewed to identify discrete variables, including implant indication, INTERMACs profile, timing of implant, mean age and BMI, and the anticoagulation/antiplatelet regimens employed post implant. Outcomes of interest included mortality and the incidence of thrombus, bleeding, infection, stroke and renal failure. A total of 25 studies met inclusion criteria. No single variable was consistently reported, with only four studies reporting all five adverse effects. INTERMACs profile at implant and anticoagulation/antiplatelet regimen were reported in less than 50% of studies. Of those reporting mortality, there was a wide range of follow-up, from less than six months to >10 years, and the survival rate was similarly widely variable. Additionally, more than 50% of studies failed to isolate CF-BiVAD from alternative means of biventricular support, such as temporary support platforms, TAH, and pulsatile VADs. Therefore high-quality quantitative analysis is not possible. In summary, CF-BiVAD literature has a very heterogenous reporting of data. Standard reporting criteria may allow for future analyses to determine which patient characteristics portend a favorable outcome with CF-BiVAD implantation.

Pre-operative atrial fibrillation and early right ventricular failure after left ventricular assist device implantation: a systematic review and meta-analysis

BACKGROUND

Right ventricular failure (RVF) remains a major cause of morbidity and mortality after left ventricular assist device (LVAD). Atrial fibrillation (AF) is known for its deleterious effects on cardiac function and hemodynamics. The association of pre-operative AF with the risk of early post-LVAD RVF has not been well described.

METHOD

A comprehensive literature search was performed through April, 9 2021. Cohort studies comparing the risk of post-operative RVF and/or need for right ventricular assist device (RVAD) after LVAD in patients with or without AF were included. Pooled odds ratio (OR) with 95% confidence intervals (CI) and I² statistic were calculated using the random-effects model.

RESULTS

Six studies were included in the analysis. Post-operative RVF was reported in 5 studies (1,841 patients) and RVAD use was reported in 4 studies (1,355 patients). There is a non-significant trend toward a higher risk of post-operative RVF in the AF group (pooled OR=1.25, 95%CI=0.99-1.58). No significant association between AF and RVAD use is noted (pooled OR=1.17, 95%CI=0.82-1.66).

CONCLUSIONS

Pre-operative AF is not significantly associated with higher risks of post-operative RVF and RVAD use after LVAD implantation, although the trend toward higher post-operative RVF is observed in patients with pre-operative AF. Additional research using a larger study population is warranted to better understand the association of pre-operative AF and the development of post-LVAD RVF.

Predicting post-operative right ventricular failure using video-based deep learning

Despite progressive improvements over the decades, the rich temporally resolved data in an echocardiogram remain underutilized. Human assessments reduce the complex patterns of cardiac wall motion, to a small list of measurements of heart function. All modern echocardiography artificial intelligence (AI) systems are similarly limited by design - automating measurements of the same reductionist metrics rather than utilizing the embedded wealth of data. This underutilization is most evident where clinical decision making is guided by subjective assessments of disease acuity. Predicting the likelihood of developing post-operative right ventricular failure (RV failure) in the setting of mechanical circulatory support is one such example. Here we describe a video AI system trained to predict post-operative RV failure using the full spatiotemporal density of information in pre-operative echocardiography. We achieve an AUC of 0.729, and show that this ML system significantly outperforms a team of human experts at the same task on independent evaluation.

Outcome of right ventricular assist device implantation following left ventricular assist device implantation: Systematic review and meta-analysis

Objectives:

The main aim was a systematic evaluation of the current evidence on outcomes for patients undergoing right ventricular assist device (RVAD) implantation following left ventricular assist device (LVAD) implantation.

Methods:

This systematic review was registered on PROSPERO (CRD42019130131). Reports evaluating in-hospital as well as follow-up outcome in LVAD and LVAD/RVAD implantation were identified through Ovid Medline, Web of Science and EMBASE. The primary endpoint was mortality at the hospital stay and at follow-up. Pooled incidence of defined endpoints was calculated by using random effects models.

Results:

A total of 35 retrospective studies that included 3260 patients were analyzed. 30 days mortality was in favour of isolated LVAD implantation 6.74% (1.98–11.5%) versus 31.9% (19.78–44.02%) p = 0.001 in LVAD with temporary need for RVAD. During the hospital stay the incidence of major bleeding was 18.7% (18.2–19.4%) versus 40.0% (36.3–48.8%) and stroke rate was 5.6% (5.4–5.8%) versus 20.9% (16.8–28.3%) and was in favour of isolated LVAD implantation. Mortality reported at short-term as well at long-term was 19.66% (CI 15.73–23.59%) and 33.90% (CI 8.84–59.96%) in LVAD respectively versus 45.35% (CI 35.31–55.4%) p ⩽ 0.001 and 48.23% (CI 16.01–80.45%) p = 0.686 in LVAD/RVAD group respectively.

Conclusion:

Implantation of a temporary RVAD is allied with a worse outcome during the primary hospitalization and at follow-up. Compared to isolated LVAD support, biventricular mechanical circulatory support leads to an elevated mortality and higher incidence of adverse events such as bleeding and stroke.

Prediction of right heart failure after left ventricular assist implantation: external validation of the EUROMACS right-sided heart failure risk score

AIMS

Prediction of right heart failure (RHF) after left ventricular assist device (LVAD) implant remains a challenge. The EUROMACS right-sided heart failure (EUROMACS-RHF) risk score was proposed as a prediction tool for post-LVAD RHF but lacks from large external validation. The aim of our study was to externally validate the score.

METHODS AND RESULTS

From January 2007 to December 2017, 878 continuous-flow LVADs were implanted at three tertiary centres. We calculated the EUROMACS-RHF score in 662 patients with complete data. We evaluated its predictive performance for early RHF defined as either (i) need for short- or long-term right-sided circulatory support, (ii) continuous inotropic support for ≥14 days, or (iii) nitric oxide for ≥48 h post-operatively. Right heart failure occurred in 211 patients (32%). When compared with non-RHF patients, pre-operatively they had higher creatinine, bilirubin, right atrial pressure, and lower INTERMACS class (P < 0.05); length of stay and in-hospital mortality were higher. Area under the ROC curve for RHF prediction of the EUROMACS-RHF score was 0.64 [95% confidence interval (CI) 0.60-0.68]. Reclassification of patients with RHF was significantly better when applying the EUROMACS-RHF risk score on top of previous published scores. Patients in the high-risk category had significantly higher in-hospital and 2-year mortality [hazard ratio: 1.64 (95% CI 1.16-2.32) P = 0.005].

CONCLUSION

In an external cohort, the EUROMACS-RHF had limited discrimination predicting RHF. The clinical utility of this score remains to be determined.

Right heart failure considerations in pediatric ventricular assist devices

Right heart failure (RHF) is a vexing problem in children after left ventricular assist device (LVAD) implantation that can negatively impact transplant candidacy and survival. Anticipation, prevention, early identification and appropriate medical and device management of RHF are important to successful LVAD outcomes. However, there is limited pediatric evidence to guide practice. This pediatric-focused review summarizes the relevant literature and describes the harmonized approach to RHF from the Advanced Cardiac Therapies Improving Outcomes Network (ACTION). This review seeks to improve RHF outcomes through the sharing of best practices and experience across the pediatric VAD community.

Contemporary outcomes of continuous-flow biventricular assist devices

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.

Thoracotomy versus sternotomy? The effect of surgical approach on outcomes after left ventricular assist device implantation: A review of the literature and meta-analysis

BACKGROUND AND AIM

Thoracotomy approaches to left ventricular assist device (LVAD) implantation may reduce surgical morbidity and, through preservation of the pericardial restraint over the right heart, may reduce the incidence of right ventricular failure (RVF).

METHODS

A meta-analysis of all original studies describing the effect of the surgical approach on postoperative outcomes after LVAD implantation was performed. Postoperative outcomes analyzed.

RESULTS

Thirteen studies were included with 692 patients undergoing a sternotomy and 373 a thoracotomy approach. Patients undergoing a thoracotomy approach had a higher comorbid status (INTERMACS 1-2: 56% vs. 44%; p = .0004), but were less likely to undergo a concomitant procedure (4% vs. 15%; p = .0002) than patients undergoing a sternotomy approach. Patients undergoing a thoracotomy approach demonstrated a reduced incidence of RVF (OR, .47; CI, .23-.97; p = .04), reexploration for bleeding (OR, .55; CI, .32-.94; p = .03), perioperative blood transfusion (SMD, -.30; CI, -.49 to -.11; p = .002), LOS (-5.57; -10.56 to -.59; p = .03), and mortality (OR, .57; CI, .33-.98; p = .04), but no difference in RVAD requirement or stroke were noted. Metaregression demonstrated that the performance of a concomitant procedure did not modify the effect of the surgical approach on the primary endpoints of RVF or RVAD requirement.

CONCLUSIONS

In the current meta-analysis including over 1000 patients undergoing LVAD implantation, a thoracotomy approach was associated with a reduced incidence of RVF (but not RVAD requirement), bleeding, LOS, and mortality. No difference in stroke rates was noted. These findings not only offer additional support as to the feasibility of a thoracotomy approach for LVAD implantation but also suggest a potential superiority over a sternotomy approach.

VE/VCO2 slope predicts RV dysfunction and mortality after left ventricular assist device: a fresh look at cardiopulmonary stress testing for prognostication

Preoperative cardiopulmonary exercise testing (CPET) is well validated for prognostication before advanced surgical heart failure therapies, but its role in prognostication after LVAD surgery has never been studied. VE/VCO2 slope is an important component of CPET which has direct pathophysiologic links to right ventricular (RV) performance. We hypothesized that VE/VCO₂ slope would prognosticate RV dysfunction after LVAD. All CPET studies from a single institution were collected between September 2009 and February 2019. Patients who ultimately underwent LVAD implantation were selectively analyzed. Peak VO2 and VE/VCO2 slope were measured for all patients. We evaluated their association with hemodynamic, echocardiographic and clinical markers of RV dysfunction as well mortality. Patients were stratified into those with a ventilatory class of III or greater. (VE/VCO2 slope of ≥ 36, n = 43) and those with a VE/VCO2 slope < 36 (n = 27). We compared the mortality between the 2 groups, as well as the hemodynamic, echocardiographic and clinical markers of RV dysfunction. 570 patients underwent CPET testing. 145 patients were ultimately referred to the advanced heart failure program and 70 patients later received LVAD implantation. Patients with VE/VCO2 slope of ≥ 36 had higher mortality (30.2% vs. 7.4%, p = 0.02) than patients with VE/VCO2 slope < 36 (n = 27). They also had a higher incidence of clinically important RVF (Acute severe 9.3% vs. 0%, Severe 32.6% vs 25.9%, p = 0.03). Patients with a VE/VCO2 slope ≥ 36 had a higher CVP than those with a lower VE/VCO2 slope (11.2 ± 6.1 vs. 6.0 ± 4.8 mmHg, p = 0.007), and were more likely to have a RA/PCWP ≥ 0.63 (65% vs. 19%, p = 0.008) and a PAPI ≤ 2 (57% vs. 13%, p = 0.008). In contrast, peak VO2 < 12 ml/kg/min was not associated with postoperative RV dysfunction or mortality. Elevated preoperative VE/VCO2 slope is a predictor of postoperative mortality, and is associated with postoperative clinical and hemodynamic markers of impaired RV performance.

5-year results of a newly implemented mechanical circulatory support program for terminal heart failure patients in a Swiss non-cardiac transplant university hospital

Background

In Switzerland, long-term circulatory support programs have been limited to heart transplant centers. In 2014, to improve the management of patients with end-stage heart failure not eligible for transplantation, we implemented a left ventricular assist device (LVAD) program for destination therapy at the University Hospital of Basel.

Methods

We described the program set-up with practical aspects. Patients aged 65 and above with therapy refractory end-stage heart failure without major contraindication for LVAD implantation were included. Younger patients with bridge-to-candidacy profile were also considered. Using the Kaplan-Meier estimate, we retrospectively analyzed the overall survival and freedom from major adverse events after LVAD implantation. We compared our results to internationally reported data.

Results

Between October 2014 and September 2019, 16 patients received an LVAD in our center. The mean age at implantation was 67.1 years. The mean EuroSCORE II was 24.4% and the median INTERMACS level was 4. Thirteen patients received an LVAD as destination therapy and three patients as bridge-to-candidacy. The overall survival was 87.5 and 70% at 1 and 2 years, respectively. Freedom from stroke was 81.3% at 1 and 2 years. Freedom from device infection was 67.7 and 58.7% at 1 and 2 years, respectively. Freedom from gastrointestinal bleeding was 75 and 56.3% at 1 and 2 years, respectively. Freedom from readmission was 50 and 31.3% and at 6 months and 1 year, respectively.

Conclusions

The Basel experience demonstrated the possible implementation of an LVAD program for destination therapy or bridge-to-candidacy in a non-transplant comprehensive heart-failure center with midterm survival results and freedom from major adverse events comparable to international registries. Patient selection remains crucial.

Trial registration

This study was registered on the ClinicalTrials.gov database (NCT04263012).

Dynamic Assessment of Pulmonary Artery Pulsatility Index Provides Incremental Risk Assessment for Early Right Ventricular Failure After Left Ventricular Assist Device

BACKGROUND

The pulmonary artery pulsatility index (PAPi) has been studied to predict right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation, but only as a single time point before LVAD implantation. Multiple clinical factors and therapies impact RV function in pre-LVAD patients. Thus, we hypothesized that serial PAPi measurements during cardiac intensive care unit (CICU) optimization before LVAD implantation would provide incremental risk stratification for early RVF after LVAD implantation.

METHODS AND RESULTS

Consecutive patients who underwent sequential pulmonary artery catherization with cardiac intensive care optimization before durable LVAD implantation were included. Serial hemodynamics were reviewed retrospectively across the optimization period. The optimal PAPi was defined by the initial PAPi + the PAPi at optimized hemodynamics. RVF was defined as need for a right ventricular assist device or prolonged inotrope use (>14 days postoperatively). Patients with early RVF had significantly lower mean optimal PAPi (3.5 vs 7.5, P < .001) compared with those who did not develop RVF. After adjusting for established risk factors of early RVF after LVAD implantation, the optimal PAPi was independently and incrementally associated with early RVF after LVAD implantation (odds ratio 0.64, 95% confidence interval 0.532-0.765, P < .0001).

CONCLUSIONS

Optimal PAPi achieved during medical optimization before LVAD implantation provides independent and incremental risk stratification for early RVF, likely identifying dynamic RV reserve.

Right ventricular failure after left ventricular assist device implantation: a review of the literature

Right ventricular failure (RVF) following left ventricular assist device (LVAD) implantation remains a major complication which may significantly impair patient outcome. The genesis of RVF is, however, multifactorial, and the mechanisms underlying such a condition have not been fully elucidated, making its prevention challenging and the course not always predictable. Although preoperative risks factors can be associated with RV impairment, the physiologic changes after the LV support, can still hamper the function of the RV. Current medical treatment options are limited and sometimes, patients with a severe post-LVAD RVF may be unresponsive to pharmacological therapy and require more aggressive treatment, such as temporary RV support. We retrieved 11 publications which we assessed and divided in groups based on the RV support [extracorporeal membrane oxygenation (ECMO), right ventricular assist device (RVAD), TandemHeart with ProtekDuo cannula]. The current review comprehensively summarizes the main studies of the literature with particular attention to the RV physiology and its changes after the LVAD implantation, the predictors and prognostic score as well as the different modalities of temporary mechanical cardio-circulatory support, and its effects on patient prognosis for RVF in such a setting. In addition, it provides a decision making of the pre-, intra and post-operative management in high- and moderate- risk patients.

Right Ventricular Failure Post-Implantation of Left Ventricular Assist Device: Prevalence, Pathophysiology, and Predictors

Despite advances in left ventricular assist device (LVAD) technology, right ventricular failure (RVF) continues to be a complication after implantation. Most patients undergoing LVAD implantation have underlying right ventricular (RV) dysfunction (either as a result of prolonged LV failure or systemic disorders) that becomes decompensated post-implantation. Additional insults include intra-operative factors or a sudden increase in preload in the setting of increased cardiac output. The current literature estimates post-LVAD RVF from 3.9% to 53% using a diverse set of definitions. A few of the risk factors that have been identified include markers of cardiogenic shock (e.g., dependence on inotropes and Interagency Registry for Mechanically Assisted Circulatory Support profiles) as well as evidence of cardiorenal or cardiohepatic syndromes. Several studies have devised multivariable risk scores; however, their performance has been limited. A new functional assessment of RVF and a novel hepatic marker that describe cholestatic properties of congestive hepatopathy may provide additional predictive value. Furthermore, future studies can help better understand the relationship between pulmonary hypertension and post-LVAD RVF. To achieve our ultimate goal-to prevent and effectively manage RVF post-LVAD-we must start with a better understanding of the risk factors and pathophysiology. Future research on the different etiologies of RVF-ranging from acute post-surgical complication to late-onset RV cardiomyopathy-will help standardize definitions and tailor therapies appropriately.

Accuracy of Postoperative Risk Scores for Survival Prediction in Interagency Registry for Mechanically Assisted Circulatory Support Profile 1 Continuous-Flow Left Ventricular Assist Device Recipients

In this study, we sought to determine the accuracy of several critical care risk scores for predicting survival of Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) Profile 1 patients after continuous-flow left ventricular assist device (CF-LVAD) placement. We retrospectively analyzed the records of 605 patients who underwent CF-LVAD implantation between 2003 and 2016. We calculated the preoperative HeartMate II Risk Score (HMRS) and preoperative Right Ventricular Failure Risk Score (RVFRS) and the following risk scores for postoperative days 1-5: HMRS, RVFRS, Model for End-stage Liver Disease (MELD), MELD-eXcluding International Normalized Ratio, Post Cardiac Surgery (POCAS) risk score, Sequential Organ Failure Assessment (SOFA) risk score, and Acute Physiology and Chronic Health Evaluation III. The preoperative scores and the postoperative day 1, 5-day mean, and 5-day maximum scores were entered into a receiver operating characteristic curve analysis to examine accuracy for predicting 30-day, 90-day, and 1-year survival. The mean POCAS score was the best predictor of 30-day and 90-day survival (area under the curve [AUC] = 0.869 and 0.816). The postoperative mean RVFRS was the best predictor of 1-year survival (AUC = 0.7908). The postoperative maximum and mean RVFRS and HMRS were more accurate than the preoperative scores. Both of these risk score measurements of acuity in the postoperative intensive care unit setting help predict early mortality after LVAD implantation.

Assessment of right ventricular function following left ventricular assist device (LVAD) implantation-The role of speckle-tracking echocardiography: A meta-analysis

BACKGROUND

Right ventricular failure (RVF) following left ventricular assist device (LVAD) implantation is associated with worse outcomes. Prediction of RVF is difficult with routine transthoracic echocardiography (TTE), while speckle-tracking echocardiography (STE) showed promising results. We performed systematic review and meta-analysis of published literature.

METHODS

We queried multiple databases to compile articles reporting preoperative or intraoperative right ventricle global longitudinal strain (RVGLS) or right ventricle free wall strain (RVFWS) in LVAD recipients. The standard mean difference (SMD) in RVGLS and RVFWS in patients with and without RVF postoperatively was pooled using random-effects model.

RESULTS

Seventeen studies were included. Patients with RVF had significantly lower RVGLS and RVFWS as compared to non-RVF patients; SMD: 2.79 (95% CI: -4.07 to -1.50; P: <.001) and -3.05 (95% CI: -4.11 to -1.99; P: <.001), respectively. The pooled odds ratio (OR) for RVF per percentage increase of RVGLS and RVFWS were 1.10 (95 CI: 0.98-1.25) and 1.63 (95% CI 1.07-2.47), respectively. In a subgroup analysis, TTE-derived GLS and FWS were significantly lower in RVF patients as compared to non-RVF patients; SMD of -3.97 (95% CI: -5.40 to -2.54; P: <.001) and -3.05 (95% CI: -4.11 to -1.99; P: <.001), respectively. There was no significant difference between RVF and non-RVF groups in TEE-derived RVGLS and RVFWS.

CONCLUSION

RVGLS and RVFWS were lower in patients who developed RVF as compared to non-RVF patients. In a subgroup analysis, TTE-derived RVGLS and RVFWS were reduced in RVF patients as compared to non-RVF patients. This difference was not reported with TEE.

Risk of Liver Dysfunction After Left Ventricular Assist Device Implantation

BACKGROUND

Incident liver dysfunction after left ventricular assist device implantation has been previously associated with adverse outcomes, yet data on perioperative risk markers are sparse.

METHODS

We retrospectively reviewed consecutive patients undergoing continuous-flow left ventricular assist device implant between 2007 and 2017 at a single institution. Perioperative variables were evaluated by univariate modeling and adjusted for false discovery rate. Variables most significantly associated with incident Interagency Registry for Mechanically Assisted Circulatory Support-defined liver dysfunction (INT-LD) were evaluated using logistic regression and optimal cutpoints were defined. One-year survival was evaluated using Kaplan-Meier analysis.

RESULTS

We included 359 patients (79% male; mean age 59 ± 13 years; 46% ischemic; 64% destination therapy). Lower right ventricular stroke work index at the time of right heart catheterization, higher right atrial pressure 6 hours after right heart catheterization, higher preoperative total bilirubin, longer cardiopulmonary bypass time, and greater volume of intraoperative ultrafiltration were most strongly associated with incident INT-LD (adjusted P < .01 for each). Initial right ventricular stroke work index less than 460 mm Hg∗mL/m2 (odds ratio [OR] 4.6; 95% confidence interval [CI], 2.3 to 9.4), 6-hour right heart catheterization 14 mm Hg or greater (OR 4.3; 95% CI, 2.1 to 8.8), cardiopulmonary bypass time longer than 137 minutes (OR 3.3; 95% CI, 1.8 to 6.2; P < .01 for all), ultrafiltration more than 2.95 L (OR 3.7; 95% CI, 2 to 6.8), and total bilirubin greater than 1.4 mg/dL (OR 2.7; 95% CI, 1.4 to 5) were each strongly associated with risk of INT-LD, which was associated with decreased unadjusted 1-year survival (P < .001).

CONCLUSIONS

Right ventricular stroke work index, right heart catheterization, cardiopulmonary bypass time, and ultrafiltration were each more strongly associated with elevated risk of INT-LD after left ventricular assist device implant than total bilirubin. Therefore, optimization of right ventricular hemodynamics and minimizing cardiopulmonary bypass time and ultrafiltration could potentially reduce the risk of liver dysfunction, but these observations require prospective validation.

Predicting the Risk of Right Ventricular Failure in Patients Undergoing Left Ventricular Assist Device Implantation

Background:

Right ventricular failure (RVF) is a cause of major morbidity and mortality after left ventricular assist device (LVAD) implantation. It is, therefore, integral to identify patients who may benefit from biventricular support early post-LVAD implantation. Our objective was to explore the performance of risk prediction models for RVF in adult patients undergoing LVAD implantation.

Methods:

A systematic search was performed on Medline, Embase, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews from inception until August 2019 for all relevant studies. Performance was assessed by discrimination (via C statistic) and calibration if reported. Study quality was assessed using the Prediction Model Risk of Bias Assessment Tool criteria.

Results:

After reviewing 3878 citations, 25 studies were included, featuring 20 distinctly derived models. Five models were derived from large multicenter cohorts: the European Registry for Patients With Mechanical Circulatory Support, Interagency Registry for Mechanically Assisted Circulatory Support, Kormos, Pittsburgh Bayesian, and Mechanical Circulatory Support Research Network RVF models. Seventeen studies (68%) were conducted in cohorts implanted with continuous-flow LVADs exclusively. The definition of RVF as an outcome was heterogenous among models. Seven derived models (28%) were validated in at least 2 cohorts, reporting limited discrimination (C-statistic range, 0.53–0.65). Calibration was reported in only 3 studies and was variable.

Conclusions:

Existing RVF prediction models exhibit heterogeneous derivation and validation methodologies, varying definitions of RVF, and are mostly derived from single centers. Validation studies of these prediction models demonstrate poor-to-modest discrimination. Newer models are derived in cohorts implanted with continuous-flow LVADs exclusively and exhibit modest discrimination. Derivation of enhanced discriminatory models and their validations in multicenter cohorts is needed.

Left Ventricular Assist Device as Destination Therapy: a State of the Science and Art of Long-Term Mechanical Circulatory Support

PURPOSE OF REVIEW

The purpose of this review is to synthesize and summarize recent developments in the care of patients with end-stage heart failure being managed with a left ventricular assist device (LVAD) as destination therapy.

RECENT FINDINGS

Although the survival of patients treated with LVAD continues to improve, the rates of LVAD-associated complication, such as right ventricular failure, bleeding complications, and major infection, remain high, and management of these patients remains challenging. The durability and hemocompatibility of LVAD support have greatly increased in recent years as a result of new technologies and novel management strategies. Challenges remain in the comprehensive care of patients with destination therapy LVADs, including management of comorbidities and optimizing patient function and quality of life.

Timing and Trends of Right Atrial Pressure and Risk of Right Heart Failure After Left Ventricular Assist Device Implantation

BACKGROUND

Elevated right atrial pressure (RAP) is associated with poor outcomes after left ventricular assist device (LVAD) implantation. However, the optimal time for RAP measurement and the importance of resolution of right heart congestion prior to LVAD implantation remain unclear.

METHODS AND RESULTS

We performed a retrospective cohort study of 134 consecutive LVAD recipients from our institution. Congestion was defined as RAP ≥ 14 mmHg and was assessed at hospital admission and implant. The primary outcome was death or right ventricular assist device (RVAD) implantation. When stratified by congestion status at admission, congested and non-congested patients had similar event-free survival rates (hazard ratio [HR]: 1.2, 95% confidence interval [CI]: 0.6-2.6). However, when stratified at implant, congested patients had a higher rate death or RVAD implantation (HR: 2.5, 95% CI: 1.1-5.6). Patients were then divided into 4 groups based on their trajectory of congestion status: no congestion, resolved congestion, new congestion, or persistent congestion. Patients with no congestion and resolved congestion had similar outcomes, whereas patients with persistent congestion had a markedly increased rate of death or RVAD implantation (HR: 3.1, 95% CI: 1.3-7.6).

CONCLUSION

RAP at LVAD implantation is more strongly associated with postoperative outcomes than admission RAP. Patients not responsive to decongestive therapies, with persistently elevated RAP, represent a high-risk cohort for adverse outcomes following LVAD implantation.

Total artificial heart: surgical technique in the patient with normal cardiac anatomy

Heart failure is a complex, growing problem with significant morbidity and mortality. Though heart transplantation remains the gold standard treatment for end-stage heart failure, there remains a national shortage of donor hearts. Mechanical circulatory support has provided an additional option for clinicians to support patients for the purposes of bridging patients to transplantation or to be used for destination therapy purposes. Despite generally favorable outcomes with univentricular support, in a subset of patients with biventricular heart failure, an isolated left ventricular assist device is not sufficient. Right ventricular failure has a negative impact on patient survival if not identified and treated promptly. The Total Artificial Heart (TAH) is the only Food and Drug Administration (FDA) approved artificial heart used for bridging patients to transplantation. Outcomes in patients who undergo implantation of the TAH at experienced centers have been good and reproducible.

Right Ventricular Function in Chronic Heart Failure: From the Diagnosis to the Therapeutic Approach

There is growing attention for the study of the right ventricle in cardiovascular disease and in particular in heart failure. In this clinical setting, right ventricle dysfunction is a significant marker of poor prognosis, regardless of the degree of left ventricular dysfunction. Novel echocardiographic methods allow for obtaining a more complete evaluation of the right ventricle anatomy and function as well as of the related abnormalities in filling pressures. Specific and effective therapies for the right ventricle dysfunction are still not well defined and this represents the most difficult and important challenge. This article focuses on available diagnostic techniques for studying right ventricle dysfunction as well as on the therapies for right ventricle dysfunction.

Left ventricle assist device pulsatility index at the time of implantation is associated with follow-up pulmonary hemodynamics

HeartMate II left ventricular assist device controllers provide data including pulsatility index, reflecting the relationship between pump function and hemodynamics. We propose that a higher pulsatility index at hospital discharge following implant may be associated with less vascular congestion and improved clinical outcomes. A retrospective analysis of 40 patients (age 59.2 ± 10.3 years) supported with the HeartMate II devices was conducted. Data revealed moderate Pearson correlations between pulsatility index at discharge and right atrial pressure, pulmonary artery systolic pressure, pulmonary artery diastolic pressure, mean pulmonary arterial pressure, and pulmonary capillary wedge pressure, respectively, post-surgery (median of 377 days), demonstrating a stronger relationship when analyzed for the EPC controller (n = 28) only (r = -.57, p < .01; r = -.38, p < .05; r = -.59, p < .01; r = -.47, p = .01 and r = -.53, p < .01, respectively). The pulsatility index derived from the EPC controller was associated with the significant risk of re-hospitalization within 1 and 2 years after the implantation of left ventricular assist device; hazard ratio = 0.557 with 95% confidence interval (0.315-0.983), p = .04 and hazard ratio = .579 (0.341-0.984), p = .04. A higher pulsatility index at discharge was associated with greater volume unloading, lower pulmonary pressures, and lower risk of all-cause re-hospitalizations within 1 and 2 years post-surgery. As such, pump-derived data may provide additional value in predicting left ventricular assist device hemodynamics.

Usefulness of regional right ventricular and right atrial strain for prediction of early and late right ventricular failure following a left ventricular assist device implant: A machine learning approach

BACKGROUND

Identifying candidates for left ventricular assist device surgery at risk of right ventricular failure remains difficult. The aim was to identify the most accurate predictors of right ventricular failure among clinical, biological, and imaging markers, assessed by agreement of different supervised machine learning algorithms.

METHODS

Seventy-four patients, referred to HeartWare left ventricular assist device since 2010 in two Italian centers, were recruited. Biomarkers, right ventricular standard, and strain echocardiography, as well as cath-lab measures, were compared among patients who did not develop right ventricular failure (N = 56), those with acute-right ventricular failure (N = 8, 11%) or chronic-right ventricular failure (N = 10, 14%). Logistic regression, penalized logistic regression, linear support vector machines, and naïve Bayes algorithms with leave-one-out validation were used to evaluate the efficiency of any combination of three collected variables in an "all-subsets" approach.

RESULTS

Michigan risk score combined with central venous pressure assessed invasively and apical longitudinal systolic strain of the right ventricular-free wall were the most significant predictors of acute-right ventricular failure (maximum receiver operating characteristic-area under the curve = 0.95, 95% confidence interval = 0.91-1.00, by the naïve Bayes), while the right ventricular-free wall systolic strain of the middle segment, right atrial strain (QRS-synced), and tricuspid annular plane systolic excursion were the most significant predictors of Chronic-RVF (receiver operating characteristic-area under the curve = 0.97, 95% confidence interval = 0.91-1.00, according to naïve Bayes).

CONCLUSION

Apical right ventricular strain as well as right atrial strain provides complementary information, both critical to predict acute-right ventricular failure and chronic-right ventricular failure, respectively.

[Acute perioperative right heart insufficiency : Diagnostics and treatment]

Acute right heart failure is often overlooked as a cause of cardiopulmonary insufficiency. The various pathologies underlying right heart failure at the level of afterload, preload and contractility, make rapid, targeted diagnostics necessary. In addition to clinical symptoms and laboratory chemical parameters, echocardiography in particular is relevant for making a diagnosis. Symptomatic treatment of the endangered patient is essential. The focus is on a reduction of right ventricular pressure and afterload, a correction of systemic hypotension and positive inotropic support of the right ventricle. Mechanical organ replacement and support procedures are increasingly being used in the case of persistent right heart failure and expand the possibilities for treatment. Decisive for the prognosis is a causal treatment adapted to the underlying triggering disease.

Intraoperative Hemodynamic and Echocardiographic Measurements Associated With Severe Right Ventricular Failure After Left Ventricular Assist Device Implantation

BACKGROUND

Severe right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation increases morbidity and mortality. We investigated the association between intraoperative right heart hemodynamic data, echocardiographic parameters, and severe versus nonsevere RVF.

METHODS

A review of LVAD patients between March 2013 and March 2016 was performed. Severe RVF was defined by the need for a right ventricular mechanical support device, inotropic, and/or inhaled pulmonary vasodilator requirements for >14 days. From a chart review, the right ventricular failure risk score was calculated and right heart hemodynamic data were collected. Pulmonary artery pulsatility index (PAPi) [(pulmonary artery systolic pressure - pulmonary artery diastolic pressure)/central venous pressure (CVP)] was calculated for 2 periods: (1) 30 minutes before cardiopulmonary bypass (CPB) and (2) after chest closure. Echocardiographic data were recorded pre-CPB and post-CPB by a blinded reviewer. Univariate logistic regression models were used to examine the performance of hemodynamic and echocardiographic metrics.

RESULTS

A total of 110 LVAD patients were identified. Twenty-five did not meet criteria for RVF. Of the remaining 85 patients, 28 (33%) met criteria for severe RVF. Hemodynamic factors associated with severe RVF included: higher CVP values after chest closure (18 ± 9 vs 13 ± 5 mm Hg; P = .0008) in addition to lower PAPi pre-CPB (1.2 ± 0.6 vs 1.7 ± 1.0; P = .04) and after chest closure (0.9 ± 0.5 vs 1.5 ± 0.8; P = .0008). Post-CPB echocardiographic findings associated with severe RVF included: larger right atrial diameter major axis (5.4 ± 0.9 vs 4.9 ± 1.0 cm; P = .03), larger right ventricle end-systolic area (22.6 ± 8.4 vs 18.5 ± 7.9 cm; P = .03), lower fractional area of change (20.2 ± 10.8 vs 25.9 ± 12.6; P = .04), and lower tricuspid annular plane systolic excursion (0.9 ± 0.2 vs 1.1 ± 0.3 cm; P = .008). Right ventricular failure risk score was not a significant predictor of severe RVF. Post-chest closure CVP and post-chest closure PAPi discriminated severe from nonsevere RVF better than other variables measured, each with an area under the curve of 0.75 (95% CI, 0.64-0.86).

CONCLUSIONS

Post-chest closure values of CVP and PAPi were significantly associated with severe RVF. Echocardiographic assessment of RV function post-CPB was weakly associated with severe RVF.

Calculation of the ALMA Risk of Right Ventricular Failure After Left Ventricular Assist Device Implantation

Right ventricular failure after continuous-flow left ventricular assist device (LVAD) implantation is still an unsolved issue and remains a life-threatening event for patients. We undertook this study to determine predictors of the patients who are candidates for isolated LVAD therapy as opposed to biventricular support (BVAD). We reviewed demographic, echocardiographic, hemodynamic, and laboratory variables for 258 patients who underwent both isolated LVAD implantation and unplanned BVAD because of early right ventricular failure after LVAD insertion, between 2006 and 2017 (LVAD = 170 and BVAD = 88). The final study patients were randomly divided into derivation (79.8%, n = 206) and validation (20.1%, n = 52) cohorts. Fifty-seven preoperative risk factors were compared between patients who were successfully managed with an LVAD and those who required a BVAD. Nineteen variables demonstrated statistical significance on univariable analysis. Multivariable logistic regression analysis identified destination therapy (odds ratio [OR] 2.0 [1.7-3.9], p = 0.003), a pulmonary artery pulsatility index <2 (OR 3.3 [1.7-6.1], p = 0.001), a right ventricle/left ventricle end-diastolic diameter ratio >0.75 (OR 2.7 [1.5-5.5], p = 0.001), an right ventricle stroke work index <300 mm Hg/ml/m (OR 4.3 [2.5-7.3], p < 0.001), and a United Network for Organ Sharing modified Model for End-Stage Liver Disease Excluding INR score >17 (OR 3.5 [1.9-6.9], p < 0.001) as the major predictors of the need for BVAD. Using these data, we propose a simple risk calculator to determine the suitability of patients for isolated LVAD support in the era of continuous-flow mechanical circulatory support devices.

Comparative Analysis of Established Risk Scores and Novel Hemodynamic Metrics in Predicting Right Ventricular Failure in Left Ventricular Assist Device Patients

BACKGROUND

Right ventricular failure (RVF) portends poor outcomes after left ventricular assist device (LVAD) implantation. Although numerous RVF predictive models have been developed, there are few independent comparative analyses of these risk models.

METHODS AND RESULTS

RVF was defined as use of inotropes for >14 days, inhaled pulmonary vasodilators for >48 hours or unplanned right ventricular mechanical support postoperatively during the index hospitalization. Risk models were evaluated for the primary outcome of RVF by means of logistic regression and receiver operating characteristic curves. Among 93 LVAD patients with complete data from 2011 to 2016, the Michigan RVF score (C = 0.74 [95% CI 0.61-0.87]; P = .0004) was the only risk model to demonstrate significant discrimination for RVF, compared with newer risk scores (Utah, Pitt, EuroMACS). Among individual hemodynamic/echocardiographic metrics, preoperative right ventricular dysfunction (C = 0.72 [95% CI 0.58-0.85]; P = .0022) also demonstrated significant discrimination of RVF. The Michigan RVF score was also the best predictor of in-hospital mortality (C = 0.67 [95% CI 0.52-0.83]; P = .0319) and 3-year survival (Kaplan-Meier log-rank 0.0135).

CONCLUSIONS

In external validation analysis, the more established Michigan RVF score-which emphasizes preoperative hemodynamic instability and target end-organ dysfunction-performed best, albeit modestly, in predicting RVF and demonstrated association with in-hospital and long-term mortality.

Mechanical circulatory support for the right ventricle in combination with a left ventricular assist device

Introduction: Right heart failure (RHF) in patients with a left ventricular assist device (LVAD) carries a poor prognosis although the treatment strategy including mechanical circulatory support for the failing right ventricle (RV) has not been well established. Areas covered: In this review, we describe an overview of RHF post-LVAD implant including natural history, prevalence, pathophysiology, outcomes, and challenges to predict RHF post-LVAD implant. Then, we focus on right ventricular assist devices (RVADs) and their clinical outcomes. Recently developed percutaneous RVADs are the major advance in this field. Finally, we discuss future perspectives to overcome limitations of the current treatment options. Expert opinion: In the absence of dedicated RVAD system RHF post-LVAD implant may have been undertreated. Now that dedicated percutaneous RVADs have emerged, surgeons are encouraged to use these new devices to improve outcomes of LVAD therapy. As experience accumulates, we should be able to establish the best possible strategy to treat early RHF post-LVAD implant. Late RHF is another form of RHF post-LVAD implant and has been underappreciated. Further research is mandatory to clarify the mechanism and risk factors. There are still unmet needs for a dedicated implantable RVAD for a subset of patients who need long-term RV support.

Preemptive Extracorporeal Life Support for Surgical Treatment of Severe Constrictive Pericarditis

BACKGROUND

Surgical treatment of constrictive pericarditis (CP) is particularly challenging because of the increased risk of right heart failure. The necessity of postoperative extracorporeal life support (ECLS) can result in mortality rates of 100%. Preemptive implantation of ECLS may improve postoperative outcomes; however, no data are currently available on its use. We conducted a retrospective study to evaluate the feasibility of our strategy.

METHODS

Between September 2012 and June 2016, ECLS was established percutaneously through the groin vessels in 12 individually selected patients with high-risk CP immediately before pericardiectomy in the operating theater as part of the surgical strategy. Prolonged weaning was performed in the intensive care unit. Demographic characteristics, perioperative data, and survival were analyzed.

RESULTS

The median patient age was 61.5 years (first quartile, third quartile: 51.3, 68.5 years), with a preoperative central venous pressure of 24 mm Hg (first quartile, third quartile: 21, 28 mm Hg). Furthermore, the pulmonary artery pressure was greater than 60 mm Hg in 50% of patients and a dip plateau sign existed in 75% before surgery. The median duration of ECLS therapy was 132 hours (first quartile, third quartile: 96, 168 hours) with a length of stay on the intensive care unit of 10 days (first quartile, third quartile: 7.0, 16.8 days). There was no intraoperative death. The cumulative 30-day, 1-year, and 5-year survival rates were 83% ± 11%, 75% ± 13%, and 75% ± 13%, respectively.

CONCLUSIONS

From our real-world data, preemptive use of perioperative ECLS, assigned by individual team decision in selected patients with severe CP, is a feasible and safe strategy.

WIPI1 is a conserved mediator of right ventricular failure

Right ventricular dysfunction is highly prevalent across cardiopulmonary diseases and independently predicts death in both heart failure (HF) and pulmonary hypertension (PH). Progression towards right ventricular failure (RVF) can occur in spite of optimal medical treatment of HF or PH, highlighting current insufficient understanding of RVF molecular pathophysiology. To identify molecular mechanisms that may distinctly underlie RVF, we investigated the cardiac ventricular transcriptome of advanced HF patients, with and without RVF. Using an integrated systems genomic and functional biology approach, we identified an RVF-specific gene module, for which WIPI1 served as a hub and HSPB6 and MAP4 as drivers, and confirmed the ventricular specificity of Wipi1, Hspb6, and Map4 transcriptional changes in adult murine models of pressure overload induced RV- versus LV- failure. We uncovered a shift towards non-canonical autophagy in the failing RV that correlated with RV-specific Wipi1 upregulation. In vitro siRNA silencing of Wipi1 in neonatal rat ventricular myocytes limited non-canonical autophagy and blunted aldosterone-induced mitochondrial superoxide levels. Our findings suggest that Wipi1 regulates mitochondrial oxidative signaling and non-canonical autophagy in cardiac myocytes. Together with our human transcriptomic analysis and corroborating studies in an RVF mouse model, these data render Wipi1 a potential target for RV-directed HF therapy.

Biomarkers in the Diagnosis, Management, and Prognostication of Perioperative Right Ventricular Failure in Cardiac Surgery-Are We There Yet?

Right ventricular failure (RVF) is a major risk factor for end organ morbidity and mortality following cardiac surgery. Perioperative RVF is difficult to predict and detect, and to date, no convenient, accurate, or reproducible measure of right ventricular (RV) function is available. Few studies have examined the use of biomarkers in RVF, and even fewer have examined their utility in the perioperative setting of patients undergoing cardiac surgery. Of the available classes of biomarkers, this review focuses on biomarkers of (1) inflammation and (2) myocyte injury/stress, due to their superior potential in perioperative RV assessment, including Galectin 3, ST2/sST2, CRP, cTN/hs-cTn, and BNP/NT-proBNP. This review was performed to help highlight the importance of perioperative RV function in patients undergoing cardiac surgery, to review the current modalities of RV assessment, and to provide a review of RV specific biomarkers and their potential utilization in the clinical and perioperative setting in cardiac surgery. Based on current evidence, we suggest the potential utility of ST2, sST2, Gal-3, CRP, hs-cTn, and NT-proBNP in predicting and detecting RVF in cardiac surgery patients, as they encompass the multifaceted nature of perioperative RVF and warrant further investigation to establish their clinical utility.

Temporary assist device support for the right ventricle: pre-implant and post-implant challenges

Severe right ventricular (RV) failure is more likely reversible than similar magnitudes of left ventricular (LV) failure and, because reversal of both adaptive remodeling and impaired contractility require most often only short periods of support, the use of temporary RV assist devices (t-RVADs) can be a life-saving therapy option for many patients. Although increased experience with t-RVADs and progresses made in the development of safer devices with lower risk for complications has improved both recovery rate of RV function and patient survival, the mortality of t-RVAD recipients can still be high but it depends mainly on the primary cause of RV failure (RVF), the severity of end-organ dysfunction, and the timing of RVAD implantation, and much less on adverse events and complications related to RVAD implantation, support, or removal. Reduced survival of RVAD recipients should therefore not discourage appropriate application of RVADs because their underuse further reduces the chances for RV recovery and patient survival. The article reviews and discusses the challenges related to the pre-implant and post-implant decision-making processes aiming to get best possible therapeutic results. Special attention is focused on pre-implant RV assessment and prediction of RV improvement during mechanical unloading, patient selection for t-RVAD therapy, assessment of unloading-promoted RV recovery, and prediction of its stability after RVAD removal. Particular consideration is also given to prediction of RVF after LVAD implantation which is usually hampered by the complex interactions between the different risk factors related indirectly or directly to the RV potential for reverse remodeling and functional recovery.

Outcomes After Extracorporeal Right Ventricular Assist Device Combined With Durable Left Ventricular Assist Device Support

BACKGROUND

Right heart failure occurs in 9% to 44% of left ventricular assist device (LVAD) implants, of which less than 10% require right ventricular assist device (RVAD) support either concurrently with the LVAD or staged, as a delayed procedure. We have reported our outcomes based on whether the RVAD was placed concurrently or staged.

METHODS

Clinical data were obtained from the Duke University Medical Center database. The study focused on all consecutive adult patients who received continuous flow LVAD with either concurrent or staged (within 7 days) extracorporeal, temporary RVAD, between October 2007 and October 2017. Adverse event profiles and ability to wean from RVAD were compared between these two groups.

RESULTS

Overall, 43 patients required an extracorporeal RVAD; 67% (n = 29) were implanted concurrently and 33% (n = 14) were implanted as staged after the LVAD. In all, 67% of patients (n = 29) could be weaned to an isolated LVAD. The 30-day, inhospital, and total mortality rates for our cohort were 14%, 28%, and 51% respectively. The mortality rate in the study period for the staged implants was 71% versus 45% for the concurrent implants (p = 0.101). In addition, staged RVAD implantation carried a significantly higher rate of postoperative renal failure (64% versus 28%, p = 0.044).

CONCLUSIONS

There was a low incidence of need for RVAD in our cohort. The majority could be weaned to an isolated LVAD. Morbidity and mortality rates of this mode of biventricular support remain high. Early institution of RVAD support was associated with reduced rates of post-LVAD renal failure rates.