Is severe right ventricular failure in left ventricular assist device recipients a risk factor for unsuccessful bridging to transplant and post-transplant mortality

PLACE: Multicenter Study for Right Ventricular Failure on Mechanical Cardiocirculatory Supports

Isolated acute right ventricular failure (aRVF) is associated with poor prognosis in different scenarios. In severe conditions, temporary mechanical cardiocirculatory support (tMCS) is required. PLACE is an international, retrospective, multicenter registry including 17 centers that investigated patients affected by isolated aRVF and treated with various types of tMCS from January 2000 to December 2020. The registry included 644 (69.6% males, mean age: 55 years) patients. The most frequent etiologies were post-left ventricular assist device implantation (LVAD) and postcardiotomy shock. These patients received mostly mechanical circulatory support (MCS) and veno-arterial extracorporeal membrane oxygenation. Mean tMCS duration was 9 days, weaning was achieved in 70.5% of the patients, and the major cause of death on support was multiorgan failure (50.5%). The mortality rate was 45 and 48.4% in-hospital and at 3 month follow-up, respectively. Multivariable logistic regression analysis identified age, aRVF due to acute pulmonary hypertension, bilirubin level, and oliguria or anuria at tMCS implantation as risk factors for in-hospital mortality. Conversely, aRVF after LVAD was found to be associated with a lower risk of early mortality. In-hospital and 3 months mortality occurred in less than half of the aRVF-supported subjects. Furthermore, several preimplant aspects such as age, organ function, and type of tMCS are independently associated with in-hospital and 3 month mortality.

Preoperative passive venous pressure-driven cardiac function determines left ventricular assist device outcomes

BACKGROUND

Right heart output in heart failure can be compensated through increasing systemic venous pressure. We determined whether the magnitude of this "passive cardiac output" can predict LVAD outcomes.

METHODS

This was a retrospective review of 383 patients who received a continuous-flow LVAD at the University of Michigan between 2012 and 2021. Pre-LVAD cardiac output driven by venous pressure was determined by dividing right atrial pressure by mean pulmonary artery pressure, multiplied by total cardiac output. Normalization to body surface area led to the passive cardiac index (PasCI). The Youden J statistic was used to identify the PasCI threshold, which predicted LVAD death by 2 years.

RESULTS

Increased preoperative PasCI was associated with reduced survival (hazard ratio [HR], 2.27; P < .01), and increased risk of right ventricular failure (RVF) (HR, 3.46; P = .04). Youden analysis showed that a preoperative PasCI ≥0.5 (n = 226) predicted LVAD death (P = .10). Patients with PasCI ≥0.5 had poorer survival (P = .02), with a trend toward more heart failure readmission days (mean, 45.09 ± 67.64 vs 35.13 ± 45.02 days; P = .084) and increased gastrointestinal bleeding (29.2% vs 20.4%; P = .052). Additionally, of the 97 patients who experienced readmissions for heart failure, those with pre-LVAD implantation PasCI ≥0.5 were more likely to have more than 1 readmission (P = .05).

CONCLUSIONS

Although right heart output can be augmented by raising venous pressure, this negatively impacts end-organ function and increases heart failure readmission days. Patients with a pre-LVAD PasCI ≥0.5 have worse post-LVAD survival and increased RVF. Using the PasCI metric in isolation or incorporated into a predictive model may improve the management of LVAD candidates with RV dysfunction.

The Role of Artificial Intelligence and Machine Learning in the Prediction of Right Heart Failure after Left Ventricular Assist Device Implantation: A Comprehensive Review

One of the most challenging and prevalent side effects of LVAD implantation is that of right heart failure (RHF) that may develop afterwards. The purpose of this study is to review and highlight recent advances in the uses of AI in evaluating RHF after LVAD implantation. The available literature was scanned using certain key words (artificial intelligence, machine learning, left ventricular assist device, prediction of right heart failure after LVAD) was scanned within Pubmed, Web of Science, and Google Scholar databases. Conventional risk scoring systems were also summarized, with their pros and cons being included in the results section of this study in order to provide a useful contrast with AI-based models. There are certain interesting and innovative ML approaches towards RHF prediction among the studies reviewed as well as more straightforward approaches that identified certain important predictive clinical parameters. Despite their accomplishments, the resulting AUC scores were far from ideal for these methods to be considered fully sufficient. The reasons for this include the low number of studies, standardized data availability, and lack of prospective studies. Another topic briefly discussed in this study is that relating to the ethical and legal considerations of using AI-based systems in healthcare. In the end, we believe that it would be beneficial for clinicians to not ignore these developments despite the current research indicating more time is needed for AI-based prediction models to achieve a better performance.

Blood flow kinetic energy is a novel marker for right ventricular global systolic function in patients with left ventricular assist device therapy

Objectives

Right ventricular (RV) failure remains a major concern in heart failure (HF) patients undergoing left ventricular assist device (LVAD) implantation. We aimed to measure the kinetic energy of blood in the RV outflow tract (KE-RVOT) - a new marker of RV global systolic function. We also aimed to assess the relationship of KE-RVOT to other echocardiographic parameters in all subjects and assess the relationship of KE-RVOT to hemodynamic parameters of RV performance in HF patients.

Methods

Fifty-one subjects were prospectively enrolled into 4 groups (healthy controls, NYHA Class II, NYHA Class IV, LVAD patients) as follows: 11 healthy controls, 32 HF patients (8 NYHA Class II and 24 Class IV), and 8 patients with preexisting LVADs. The 24 Class IV HF patients included 21 pre-LVAD and 3 pre-transplant patients. Echocardiographic parameters of RV function (TAPSE, St', Et', IVA, MPI) and RV outflow color-Doppler images were recorded in all patients. Invasive hemodynamic parameters of RV function were collected in all Class IV HF patients. KE-RVOT was derived from color-Doppler imaging using a vector flow mapping proprietary software. Kruskal-Wallis test was performed for comparison of KE-RVOT in each group. Correlation between KE-RVOT and echocardiographic/hemodynamic parameters was assessed by linear regression analysis. Receiver operating characteristic curves for the ability of KE-RVOT to predict early phase RV failure were generated.

Results

KE-RVOT (median ± IQR) was higher in healthy controls (55.10 [39.70 to 76.43] mW/m) than in the Class II HF group (22.23 [15.41 to 35.58] mW/m, p < 0.005). KE-RVOT was further reduced in the Class IV HF group (9.02 [5.33 to 11.94] mW/m, p < 0.05). KE-RVOT was lower in the LVAD group (25.03 [9.88 to 38.98] mW/m) than the healthy controls group (p < 0.005). KE-RVOT had significant correlation with all echocardiographic parameters and no correlation with invasive hemodynamic parameters. RV failure occurred in 12 patients who underwent LVAD implantation in the Class IV HF group (1 patient was not eligible due to death immediately after the LVAD implantation). KE-RVOT cut-off value for prediction of RV failure was 9.15 mW/m (sensitivity: 0.67, specificity: 0.75, AUC: 0.66).

Conclusions

KE-RVOT, a novel noninvasive measure of RV function, strongly correlates with well-established echocardiographic markers of RV performance. KE-RVOT is the energy generated by RV wall contraction. Therefore, KE-RVOT may reflect global RV function. The utility of KE-RVOT in prediction of RV failure post LVAD implantation requires further study.

A novel metrics to predict right heart failure after left ventricular assist device implantation

BACKGROUND

Right Heart Failure (RHF) is a severe complication that can occur after left ventricular assist device (LVAD) implantation, increasing early and late mortality. Although numerous RHF predictive scores have been developed, limited data exist on the external validation of these models. We therefore aimed at comparing existent risk score models and identifying predictors of severe RHF at our center.

METHODS

In this retrospective, single-center analysis, clinical, biological and functional data were collected in patients implanted with a LVAD between 2011 and 2020. Early severe RHF was defined as the use of inotropes for ≥ 14 days, nitric oxide use for ≥ 48 h or unplanned right-sided circulatory support. Risk models were evaluated for the primary outcome of RHF or RVAD implantation by means of logistic regression and receiver operating characteristic curves.

RESULTS

Among 92 patients implanted, 24 (26%) developed early severe RHF. The EUROMACS-RHF risk score performed the best in predicting RHF (C = 0.82-95% CI: 0.68-0.90), compared with the other scores (Michigan, CRITT). In addition, we developed a new model, based on four variables selected for the best reduced logistic model: the INTERMACS level, the number of inotropes used, the ratio of right atrial/pulmonary capillary wedge pressure and the ratio of right ventricle/left ventricle diameters by echocardiography. This model demonstrated significant discrimination of RHF (C = 0.9-95% CI: 0.76-0.96).

CONCLUSION

Amongst available risk scores, EUROMACS-RHF performs best to predict the occurrence of RHF after LVAD implantation. Our model's performance compares well to the EUROMACS-RHF score, adding a more objective parameter to RV function evaluation.

Tricuspid Valve Surgery in Patients Receiving Left Ventricular Assist Devices

BACKGROUND

 Tricuspid regurgitation (TR) is common and related to poor prognosis in patients after left ventricular assist device (LVAD) implantation. The concomitant tricuspid valve surgery (TVS) at the time of LVAD implantation on short and long-term outcomes are controversial in current evidence.

METHODS

 This is a single-center, observational, retrospective study. We enrolled patients with moderate-to-severe TR who received LVAD implantations from 2009 to 2020. Postoperative right ventricular failure (RVF), right ventricular assist device (RVAD) use, hospital mortality, new-onset renal replacement therapy (RRT), and acute kidney injury (AKI) were evaluated retrospectively.

RESULTS

 Sixty-eight patients were included, 36 with and 32 without concomitant TVS. Baseline characteristics did not differ between the two groups. Patients receiving TVS had significantly increased incidences of postoperative RVF (52.8 vs. 25.0%, p = 0.019), RVAD implantation (41.7 vs. 18.8%, p = 0.041), and new-onset RRT (22.2 vs. 0%, p = 0.004). No difference in the incidence of AKI and hospital mortality was detected. Besides, these associations remained consistent in patients who underwent LVAD implantation via median sternotomy. During a median follow-up of 2.76 years, Kaplan-Meier analysis and competing-risk analysis showed that TVS was not associated with better overall survival in patients after LVAD implantation compared with the no-TVS group.

CONCLUSION

 Our study suggests that concomitant TVS failed to show benefits in patients receiving LVAD implantation. Even worse, concomitant TVS is associated with significantly increased incidences of RVF, RVAD use, and new-onset of RRT. Considering the small sample size and short follow-up, these findings warrant further study.

Predicting, Recognizing, and Treating Right Heart Failure in Patients Undergoing Durable LVAD Therapy

Despite advancing technology, right heart failure after left ventricular assist device implantation remains a significant source of morbidity and mortality. With the UNOS allocation policy change, a larger proportion of patients proceeding to LVAD are destination therapy and consist of an overall sicker population. Thus, a comprehensive understanding of right heart failure is critical for ensuring the ongoing success of durable LVADs. The purpose of this review is to describe the effect of LVAD implantation on right heart function, review the diagnostic and predictive criteria related to right heart failure, and discuss the current evidence for management and treatment of post-LVAD right heart failure.

Right Heart Catheterization in Patients with Advanced Heart Failure: When to Perform? How to Interpret?

Right heart catheterization is an established cornerstone of advanced heart failure management, as a clear understanding of the patient's hemodynamic status offers insight into diagnosis, prognosis, and management. In this review, the authors will describe the role of right heart catheterization in the diagnosis and management of shock, in the context of left ventricular assist devices, in the assessment of heart transplant candidacy, and also explore future directions of implantable monitoring devices for pulmonary artery and left atrial pressure monitoring.

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.

Four-quadrant visualization of systemic circulatory equilibrium: right ventricular failure after left ventricular assist device implantation

Right ventricular failure (RVF) is a serious adverse event after left ventricular assist device (LVAD) implantation but difficult to be characterized. This study aimed to visualize the dynamic circulatory equilibrium of acute RVF after LVAD implantation using a new four-quadrant diagram constructed by 1) cardiac function with central venous pressure (CVP) and cardiac index (CI) axes, 2) arterial vascular resistance with CI and mean blood pressure (mBP) axes, 3) pressure-diuretic function with mBP and net urinary sodium output (net U-Na) axes, and 4) venous compliance with net U-Na and CVP axes. Twenty LVAD patients were stratified into two groups, group S (≤10 days) and group L (>10 days), according to duration of postoperative inotropic support. The preoperative equilibrium loops were small in both groups. In the early postoperative phase, the loop in group S became dramatically enlarged to the left and upward, indicating increased CVP and CI by LVAD support. In group L, however, augmentation of CI was smaller despite similarly increased CVP, and net U-Na was decreased despite increased mBP. In the late postoperative phase, the equilibrium loop in group L recovered as similar to that seen in group S. Thus, acute RVF, as shown in group L, was characterized by the shape of the loop constructed by marked increased CVP, a relatively small increase in CI, and concomitant impairment of pressure natriuresis. In conclusion, the novel four-quadrant presentation of systemic circulatory equilibrium provides clear visualization of RVF after LVAD implantation, thus serving as a useful guide for prompt and optimal management.NEW & NOTEWORTHY Systemic circulatory dynamics are regulated by various negative feedback systems, including cardiac, arterial, venous, and renal functions, as well as autonomic nervous systems. The present novel four-quadrant presentation of their functions allows clear visualization of dynamic organ-to-organ interactions that can lead to a new circulatory equilibrium after therapeutic intervention. This new system physiological framework can serve as a useful guide for prompt and optimal management of circulatory malfunction.

Perioperative Right Ventricular Dysfunction: Analysis of Outcomes

Right ventricular dysfunction (RVD) is a well-known prognostic factor for adverse outcomes in cardiovascular medicine. The right ventricle (RV) in medically managed heart failure patients and in surgical patients perioperatively generally is overshadowed by left ventricular disease. However, with advancement of various diagnostic tools and better understanding of its functional anatomy, the role of the RV is emerging in many clinical conditions. The failure of one ventricle has significant effect on the function of the other ventricle and it is predominantly due to ventricular interdependence.¹ The etiology of RVD is multifactorial and irrespective of etiology. RVD has been associated with significant increases in morbidity and mortality in various clinical scenarios.^2,3 The primary objective of this comprehensive review is to analyze various etiology-related outcomes of RVD in the perioperative population.

Outcome of Extracorporeal Ventricular Assist Device for Cardiogenic Shock as a Bridge to Transplantation

Background

The extracorporeal ventricular assist device (e-VAD) system is designed for left ventricular support using a permanent life support console. This study aimed to determine the impact of temporary e-VAD implantation bridging on posttransplant outcomes.

Methods

We reviewed the clinical records of 6 patients with the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile 1, awaiting heart transplantation, who were provided with temporary e-VAD from 2018 to 2019. The circuit comprised a single centrifugal pump without an oxygenator. The e-VAD inflow cannula was inserted into the apex of the left ventricle, and the outflow cannula was positioned in the ascending aorta. The median follow-up duration was 8.4±6.9 months.

Results

After e-VAD implantation, lactate dehydrogenase levels significantly decreased, and Sequential Organ Failure Assessment scores significantly improved. Bedside rehabilitation was possible in 5 patients. After a mean e-VAD support duration of 14.5±17.3 days, all patients were successfully bridged to transplantation. After transplantation, 5 patients survived for at least 6 months.

Conclusion

e-VAD may reverse end-organ dysfunction and improve outcomes in INTERMACS I heart transplant patients.

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 atrial versus right ventricular HeartWare HVAD position in patients on biventricular HeartWare HVAD support: A systematic review

In patients with biventricular heart failure or refractory right heart failure following HeartWare HVAD placement, off-label placement of a right-sided HeartWare HVAD has been described both in the right ventricular (RV) and right atrial (RA) positions. We sought to evaluate and compare the outcomes of right-sided HeartWare HVAD using the RA versus RV approach. An electronic search was performed in the English literature to identify all reports of left- and right-heart support with HeartWare HVAD. Of the 1,288 articles identified, 13 articles with 56 cases met inclusion criteria. Patient-level data were extracted and analyzed. The median patient age was 52 years (IQR 33.0-59.0) and 40/50 (80.0%) were male. Overall, 21/56 patients (37.5%) had RA HVAD, while 35/56 (62.5%) had RV HVAD. Most underwent concomitant HVAD placement [RA: 17/21 (81.0%) vs. RV: 31/35 (88.6%), P = .69]. In those who did not, the median time between left and right HVAD was 10 days (IQR 7-14) for RA HVAD and 12 days (IQR 8-30) for RV HVAD (P = .77). The median time of support was 351 days (IQR 136-626) for RA HVAD compared to 135 days (IQR 61-244) for RV HVAD (P = .02). Pump thrombosis occurred at a similar rate [RA: 3/10 (30.0%) vs. RV: 6/20 (30.0%), P = 1], as did GI bleeding [RA: 10/35 (28.6%) vs. RV: 5/21 (23.8%), P = .94] during the follow-up time period. Kaplan-Meier analysis when censored for transplant showed higher survival with RA HVAD compared to RV HVAD (P = .036), with an estimated survival at 1 year of 91.7% (95% CI 77.3-100.0) in RA HVAD versus 66.2% (95% CI 48.9-89.6) for RV HVAD. RA HVAD appears to be a viable option for durable right-sided support with outcomes at least comparable to RV HVAD.

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.

2019 EACTS Expert Consensus on long-term mechanical circulatory support

Long-term mechanical circulatory support (LT-MCS) is an important treatment modality for patients with severe heart failure. Different devices are available, and many-sometimes contradictory-observations regarding patient selection, surgical techniques, perioperative management and follow-up have been published. With the growing expertise in this field, the European Association for Cardio-Thoracic Surgery (EACTS) recognized a need for a structured multidisciplinary consensus about the approach to patients with LT-MCS. However, the evidence published so far is insufficient to allow for generation of meaningful guidelines complying with EACTS requirements. Instead, the EACTS presents an expert opinion in the LT-MCS field. This expert opinion addresses patient evaluation and preoperative optimization as well as management of cardiac and non-cardiac comorbidities. Further, extensive operative implantation techniques are summarized and evaluated by leading experts, depending on both patient characteristics and device selection. The faculty recognized that postoperative management is multidisciplinary and includes aspects of intensive care unit stay, rehabilitation, ambulatory care, myocardial recovery and end-of-life care and mirrored this fact in this paper. Additionally, the opinions of experts on diagnosis and management of adverse events including bleeding, cerebrovascular accidents and device malfunction are presented. In this expert consensus, the evidence for the complete management from patient selection to end-of-life care is carefully reviewed with the aim of guiding clinicians in optimizing management of patients considered for or supported by an LT-MCS device.

Temporary Right Ventricular Assist Device Insertion via Left Thoracotomy after Left Ventricular Assist Device Implantation

Right heart failure is a relatively common complication after left ventricular assist device (LVAD) implantation. Severe right heart failure can be managed by temporary right ventricular assist device (RVAD) implantation. However, trans-sternal RVAD insertion requires a subsequent third sternotomy for cannula removal. Herein, we present a case of RVAD insertion via a left anterior mini-thoracotomy after LVAD implantation in a patient with alcohol-induced cardiomyopathy.

Choosing Between Left Ventricular Assist Devices and Biventricular Assist Devices

Right ventricular failure following left ventricular assist devices implantation is a serious complication associated with high mortality. In patients with or at high risk of developing right ventricular failure, biventricular support is recommended. Because univentricular support is associated with high survival rates, biventricular support is often undertaken as a last resort. With the advent of newer right ventricular and biventricular systems under design and testing, better differentiation is required to ensure optimal patients care. Clear guidelines on patient selection, time of intervention and device selection are required to improve patient outcomes.

Prophylactic Right Ventricular Assist Device for High-Risk Patients Undergoing Valve Corrective Surgery

Background

Right ventricular failure (RVF) after cardiac surgery is associated with poor outcomes. Treatment commonly consists of afterload reduction, contractility optimization, and systemic vasopressors. The aim of this study was to propose a novel strategy of prophylactic right ventricular assist device (RVAD) insertion during valve corrective surgery for patients at high risk for RVF.

Methods

Between 2014 and 2017, 10 consecutive patients at high risk for RVF (severe baseline right ventricular dysfunction or systemic pulmonary artery pressures) underwent valve reconstructive surgery with prophylactic RVAD insertion. We reviewed patient characteristics and outcomes.

Results

All 10 patients had successful RVAD insertion, support and wean, and survival to hospital discharge. Generally, the right ventricle showed echocardiographic evidence of worsening function perioperatively but recovery of function at the time of follow-up. Patients required minimal inotropic support, and no patients required extracorporeal membrane oxygenation. Major complications included prolonged mechanical ventilation (n = 4), metabolic encephalopathy (n = 1), and sternal wound infection (n = 2). At a mean follow-up of 445.1 ± 230.9 days, 7 of 8 patients had clinically New York Heart Association functional class 1 (n = 7), and 1 patient had New York Heart Association functional class 2 (n = 1). There were 2 late mortalities.

Conclusion

Prophylactic RVAD insertion may be useful in supporting patients at high risk for RVF perioperatively when undergoing high-risk valve corrective surgery. Further investigation is warranted.

Left Ventricular Assist Device Implantation in Patients With Optimal and Borderline Echocardiographic Assessment of Right Ventricle Function

BACKGROUND

Left ventricular assist devices (LVADs) are used for treatment of end-stage heart failure. Outcomes are dependent on right ventricle (RV) function. Prediction of RV function after LVAD implantation is crucial for device selection and patient outcome. The aim of our study was to compare early LVAD course in patients with optimal and borderline echocardiographic parameters of RV function.

MATERIAL AND METHODS

We retrospectively reviewed 24 male patients with LVAD implantation. The following echocardiographic data of RV function were collected: FAC (fractional area change) with optimal value > 20%, tricuspid annulus plane systolic excursion >15 mm, RV diameter < 50mm, and right-to-left ventricle ratio < 0.57 (RV/LV). Patients were divided into group 1 (12 patients) with transthoracic echocardiography parameters in optimal ranges and group 2 (12 patients) with suboptimal transthoracic echocardiography findings. Study endpoints were mortality, discharge from the intensive care unit, and RV dysfunction. Demographics, postoperative clinical outcomes, comorbidities, complications, and results in a 30-day period were analyzed between groups.

RESULTS

Echocardiography parameters differed significantly between groups 1 and 2 according to FAC (31.8% vs 24.08%; P = .005), RV4 (45.08 mm vs 51.69 mm; P = .02), and RV/LV ratio (0.6 vs 0.7; P = .009). Patients did not differ according to course of disease, comorbidities before implantation, or complications. One patient from each group died. Patients in group 2 experienced more pulmonary hypertension, required increased doses of catecholamines, and stayed in the intensive care unit longer. No RV dysfunction was noted.

CONCLUSIONS

Borderline FAC, tricuspid annulus plane systolic excursion, and RV4 add RV/LV ratio prolonged recovery after LVAD implantation even with no RV failure. Parameters chosen for qualification are in safe ranges.

Wave Intensity Analysis of Right Ventricular Function during Pulsed Operation of Rotary Left Ventricular Assist Devices

Changing the speed of left ventricular assist devices (LVADs) cyclically may be useful to restore aortic pulsatility; however, the effects of this pulsation on right ventricular (RV) function are unknown. This study investigates the effects of direct ventricular interaction by quantifying the amount of wave energy created by RV contraction when axial and centrifugal LVADs are used to assist the left ventricle. In 4 anesthetized pigs, pressure and flow were measured in the main pulmonary artery and wave intensity analysis was used to identify and quantify the energy of waves created by the RV. The axial pump depressed the intensity of waves created by RV contraction compared with the centrifugal pump. In both pump designs, there were only minor and variable differences between the continuous and pulsed operation on RV function. The axial pump causes the RV to contract with less energy compared with a centrifugal design. Diminishing the ability of the RV to produce less energy translates to less pressure and flow produced, which may lead to LVAD-induced RV failure. The effects of pulsed LVAD operation on the RV appear to be minimal during acute observation of healthy hearts. Further study is necessary to uncover the effects of other modes of speed modulation with healthy and unhealthy hearts to determine if pulsed operation will benefit patients by reducing LVAD complications.

Evaluation and Management of Right-Sided Heart Failure: A Scientific Statement From the American Heart Association

Background and Purpose:

The diverse causes of right-sided heart failure (RHF) include, among others, primary cardiomyopathies with right ventricular (RV) involvement, RV ischemia and infarction, volume loading caused by cardiac lesions associated with congenital heart disease and valvular pathologies, and pressure loading resulting from pulmonic stenosis or pulmonary hypertension from a variety of causes, including left-sided heart disease. Progressive RV dysfunction in these disease states is associated with increased morbidity and mortality. The purpose of this scientific statement is to provide guidance on the assessment and management of RHF.

Methods:

The writing group used systematic literature reviews, published translational and clinical studies, clinical practice guidelines, and expert opinion/statements to summarize existing evidence and to identify areas of inadequacy requiring future research. The panel reviewed the most relevant adult medical literature excluding routine laboratory tests using MEDLINE, EMBASE, and Web of Science through September 2017. The document is organized and classified according to the American Heart Association to provide specific suggestions, considerations, or reference to contemporary clinical practice recommendations.

Results:

Chronic RHF is associated with decreased exercise tolerance, poor functional capacity, decreased cardiac output and progressive end-organ damage (caused by a combination of end-organ venous congestion and underperfusion), and cachexia resulting from poor absorption of nutrients, as well as a systemic proinflammatory state. It is the principal cause of death in patients with pulmonary arterial hypertension. Similarly, acute RHF is associated with hemodynamic instability and is the primary cause of death in patients presenting with massive pulmonary embolism, RV myocardial infarction, and postcardiotomy shock associated with cardiac surgery. Functional assessment of the right side of the heart can be hindered by its complex geometry. Multiple hemodynamic and biochemical markers are associated with worsening RHF and can serve to guide clinical assessment and therapeutic decision making. Pharmacological and mechanical interventions targeting isolated acute and chronic RHF have not been well investigated. Specific therapies promoting stabilization and recovery of RV function are lacking.

Conclusions:

RHF is a complex syndrome including diverse causes, pathways, and pathological processes. In this scientific statement, we review the causes and epidemiology of RV dysfunction and the pathophysiology of acute and chronic RHF and provide guidance for the management of the associated conditions leading to and caused by RHF.

Prevention and Treatment of Right Ventricular Failure During Left Ventricular Assist Device Therapy

Left ventricular assist devices (LVAD) are increasingly used for the treatment of end-stage heart failure. Right ventricular (RV) failure after LVAD implantation is an increasingly common clinical problem, occurring in patients early after continuous flow LVAD implant. RV failure is associated with a substantial increase in post-LVAD morbidity and mortality. RV failure can be predicted using preoperative hemodynamic, clinical, and echocardiographic variables and a variety of risk prediction algorithms. However, RV failure may also develop due to unanticipated intraoperative or perioperative factors. Early recognition and treatment are critical in terms of mitigating the impact of RV failure on post-LVAD outcomes.

Clinical experience with temporary right ventricular mechanical circulatory support

OBJECTIVES

This study sought to determine if indication for support affects the outcomes after temporary right ventricular mechanical circulatory support after postcardiotomy cardiogenic shock, cardiac transplant, or left ventricular assist device placement.

METHODS

A retrospective review was performed on 80 patients receiving a right ventricular assist device. Data were collected from a prospectively maintained database. Kaplan-Meier survival analysis was performed to compare survival between groups. Multivariate regression analysis was performed to identify risk factors for failure to wean from support.

RESULTS

The indication for support was postcardiotomy cardiogenic shock in 13 patients (16%), cardiac transplant in 25 patients (31%), and left ventricular assist device in 42 patients (53%). Median support time was 6 days. Device was successfully weaned in 6 postcardiotomy cardiogenic shock cases (46%), 21 cardiac transplant cases (84%), and 35 left ventricular assist device cases (83%). Survival was worse for patients with postcardiotomy cardiogenic shock compared with patients with a left ventricular assist device. Survival up to 3 months was better for patients who received immediate (n = 43) versus delayed (n = 37) support (79% vs 46%, P = .003). Weaning and survival remained static across implant era. Risk factor analysis identified postcardiotomy cardiogenic shock indication (odds ratio, 0.161; P = .007; confidence interval, 0.043-0.600) as an independent negative predictor of weaning from mechanical support.

CONCLUSIONS

Temporary right ventricular mechanical support remains an effective treatment strategy after left ventricular assist device placement with immediate support resulting in superior short-term survival. Caution should be applied in postcardiotomy cardiogenic shock when weaning and survival are poor. Overall survival outcomes have remained relatively static over time.

Perioperative Care of the Patient With the Total Artificial Heart

Advanced heart failure continues to be a leading cause of morbidity and mortality despite improvements in pharmacologic therapy. High demand for cardiac transplantation and shortage of donor organs have led to an increase in the utilization of mechanical circulatory support devices. The total artificial heart is an effective biventricular assist device that may be used as a bridge to transplant and that is being studied for destination therapy. This review discusses the history, indications, and perioperative management of the total artificial heart with emphasis on the postoperative concerns.

Current status of mechanical circulatory support for treatment of advanced end-stage heart failure: successes, shortcomings and needs

INTRODUCTION

Heart failure (HF) remains a major global burden in terms of morbidity and mortality. Despite advances in pharmacological and resynchronization device therapy, many patients worsen to end-stage HF. Although the gold-standard treatment for such patients is heart transplantation, there will always be a shortage of donor hearts. Areas covered: A left ventricular assist device (LVAD) is a valuable option for these patients as a bridge measure (to recovery, to candidacy for transplant, or to transplant itself) or as destination therapy. This review describes the current indications for and complications of the most commonly implanted LVADs. In addition, we review the potential and promising new LVADs, including the HeartMate 3, MVAD, and other LVADs. Studies investigating each were identified through a combination of online database and direct extraction of studies cited in previously identified articles. Expert commentary: The goal of LVADs has been to fill the gap between patients with end-stage HF who would likely not benefit from heart transplantation and those who could benefit from a donor heart. As of now, the use of LVADs has been limited to patients with end-stage HF, but next-generation LVAD therapy may improve both survival and quality of life in less sick patients.

Extracorporeal life support prior to left ventricular assist device implantation leads to improvement of the patients INTERMACS levels and outcome

Background

The objective of this study was to evaluate the outcome of left ventricular assist device (LVAD) implantation after initial extracorporeal life support (ECLS) in patients with cardiogenic shock and the incidence of post implantation right ventricular failure.

Methods & results

All patients on ECLS therapy for cardiogenic shock prior to LVAD implantation (n = 15) between October 2011 and January 2014 were analyzed. Baseline patient characteristics, as well as detailed pre-operative treatment and postoperative outcome data were collected retrospectively. At time of admission to our unit all patients were classified INTERMACS II or higher (12 [80%] INTERMACS I). Improvement to INTERMACS III temporary cardiac support (TCS) at time of LVAD implantation was successful in 14 patients (93.3%). End-organ function recovered during ECLS support. No patient needed ongoing ECLS or additional right ventricular support after LVAD implantation. Both in-hospital and 30-day mortality was 6.7% (n = 1). The median duration of LVAD support was 687.9 ± 374.5 days. At the end of the study (follow-up 810.7 +/- 338.9 days), 13 (86.7%) patients were alive. The majority of patients (10 [66.7%]) remained on LVAD support. Transplantation could be performed in 1 (6.7%) patient, 2 (13.3%) patients could be successfully weaned.

Conclusion

LVAD implantation in ECLS patients leads to improvement of INTERMACS level to INTERMACS III TCS status. Excellent mid-term survival comparable to true INTERMACS III-IV patients could be shown. ECLS prior to LVAD as a bridge-to-bridge therapy may help to lower mortality in primarily unstable patients.

Current Status of Mechanical Circulatory Assistance

Mechanical circulatory support has become an increasingly used management strategy for patients with both acute and chronic ventricular failure. This article briefly reviews the current state of mechanical circulatory support with a focus on indications, contraindications, and complications of currently available devices. Perioperative considerations for ventricular assist device implantation are discussed, including the decision-making process underlying the use of univentricular versus biventricular support, specific anesthetic considerations, and the role of transesophageal echocardiography where ventricular assist devices are concerned. The anesthetic considerations for the patient already supported by a ventricular assist device presenting for noncardiac surgery are also reviewed. The work concludes with a discussion of the rationale behind the next generation of continuous flow devices currently in human clinical trials.

Early Biventricular Assist Device Use in Children: A Single-Center Review of 31 Patients

Biventricular assist device (BiVAD) support is considered a risk factor for worse outcomes compared with left ventricular assist device (LVAD) alone for children with end-stage heart failure. It remains unclear whether this is because of the morbidity associated with a second device or the underlying disease severity. We aimed to show that early BiVAD support can result in good survival by analyzing our prospectively collected database for all pediatric patients who underwent BiVAD implantation. From 2005 to 2009, BiVADs were used exclusively. From 2010 to 2014, LVAD alone was considered, maintaining a low threshold for BiVAD support. All BiVADs were pulsatile devices. Thirty-one patients with median age of 3.5 years received BiVAD support. Diagnoses included dilated cardiomyopathy in 17 (55%), myocarditis in 6 (19%), and congenital heart disease in 3 (10%). Survival to transplant was achieved in 27 (87%) with a median duration of 41 days (interquartile range, 15-69). Adverse event rates (per 100 days of support) were bleeding at 0.52, infection at 1.17, and central nervous system dysfunction at 0.78. Of those who survived to transplant, 26 (96%) remain alive with a median follow-up of 55 months. These results show that BiVAD support can bridge patients to transplant with excellent long-term survival.

Outcomes of patients with right ventricular failure on milrinone after left ventricular assist device implantation

Previous studies have grouped together both patients requiring right ventricular assist devices (RVADs) with patients requiring prolonged milrinone therapy after left ventricular assist device (LVAD) implantation. We retrospectively identified 149 patients receiving LVADs and 18 (12.1%) of which developed right ventricular (RV) failure. We then separated these patients into those requiring RVADs versus prolonged milrinone therapy. This included 10 patients who were treated with prolonged milrinone and eight patients who underwent RVAD placement. Overall, the RV failure group had worse survival compared with the non-RV failure cohort (p = 0.038). However, this was only for the subgroup of patients who required RVADs, who had a 1, 6, 12, and 24 month survival of 62.5%, 37.5%, 37.5%, and 37.5%, respectively, versus 96.8%, 92.1%, 86.7%, and 84.4% for patients without RV failure (p < 0.001). Patients treated with prolonged milrinone therapy for RV failure had similar survivals compared with patients without RV failure. In the RV failure group, age, preoperative renal failure, and previous cardiac surgery were predictors of the need for prolonged postoperative milrinone. As LVADs become a more widely used therapy for patients with refractory, end-stage heart failure, it will be important to reduce the incidence of RV failure, as it yields significant morbidity and increases cost.