Temporary Right Ventricular Assist Device Support for Acute Right Heart Failure: A Single-Center Experience.

INTRODUCTION: Severe right ventricular (RV) failure is associated with significant morbidity and mortality. Although right ventricular assist devices (RVADs) are increasingly used for refractory RV failure, there is limited data on their short- and long-term outcomes. Therefore, we undertook this study to better understand our experience with temporary RVADs. METHODS: We conducted a retrospective review of all RVADS performed from 2017 to 2021. Patients supported with surgical RVADs, the Protek Duo device, and the Impella RP device were included. Patients were stratified by the type of RVAD and by etiology of RV failure. Survival was assessed by the Kaplan-Meier method and multivariable Cox proportional hazards regression models. RESULTS: From 2017 to 2021, 42 patients underwent RVAD implantation: 32 with a Protek Duo, 6 with an Impella RP, and 4 with a surgical RVAD. Majority of patients were already supported with an alternate form of mechanical support. Most patients had impaired renal function, decreased hepatic function, and lactic acidosis at the time of cannulation. The median duration of RVAD support was 8.5 [5-19] d. Survival to decannulation was 68.4%, to discharge was 47.4%, and to 1-y was 40.2%. Multivariable analysis identified elevated total bilirubin levels to be associated with 30-d mortality while increased hemoglobin levels were protective. After RVAD cannulation, the median number of pressors and inotropes was lower (P < 0.01) and the lactic acidosis was less (P < 0.01). CONCLUSIONS: In conclusion, RVAD support is associated with lower lactate levels, and decreased number of vasoactive medications, but is associated with significant morbidity and mortality.

Simultaneous minimally invasive LVAD implantation and extracorporeal RVAD placement by patient with pectus excavatum and biventricular acute heart failure.

The optimal surgical approach in patients with pectus excavatum (PEx) who need cardiac surgery remains uncertain. The challenge is even greater, if it is already foreseeable that the patient will be needed further procedure in the next future. We describe a novel sternotomy-sparing approach for minimal-invasive biventricular assist device (BiVAD) implantation in a patient with an acute heart failure (HF) due to dilated cardiomyopathy and severe PEx. Moreover, alternative approaches for ventricular assist device (VAD) implantation and timing of the repair of PEx will be discussed.

Right-Sided Mechanical Circulatory Support - A Hemodynamic Perspective.

PURPOSE OF REVIEW: Right ventricular (RV) failure is increasingly recognized as a major cause of morbidity and mortality. When RV failure is refractory to medical therapy, escalation to right-sided mechanical circulatory support (MCS) should be considered. In this review, we begin by recapitulating the hemodynamics of RV failure, then we delve into current and future right-sided MCS devices and describe their hemodynamic profiles. RECENT FINDINGS: The field of temporary right-sided MCS continues to expand, with evolving strategies and new devices actively under development. All right-sided MCS devices bypass the RV, with each bypass configuration conferring a unique hemodynamic profile. Devices that aspirate blood directly from the RV, as opposed to the RA or the IVC, have more favorable hemodynamics and more effective RV unloading. There has been a growing interest in single-access MCS devices which do not restrict patient mobility. Additionally, a first-of-its-kind percutaneous, pulsatile, right-sided MCS device (PERKAT RV) is currently undergoing investigation in humans. Prompt recognition of refractory RV failure and deployment of right-sided MCS can improve outcomes. The field of right-sided MCS is rapidly evolving, with ongoing efforts dedicated towards developing novel temporary devices that are single access, allow for patient mobility, and directly unload the RV, as well as more durable devices.

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.

Index radiographic measurements in the prediction of progression in infantile idiopathic scoliosis: a comparative analysis and description of a novel predictive model.

PURPOSE: To assess the comparative accuracy of commonly utilised index radiological measurements in the prognosis of infantile idiopathic scoliosis (IIS) and build a parsimonious prognostic model utilising these measurements. METHODS: This was a retrospective analysis of a UK population of patients with IIS. Index radiological parameters were analysed, and outcome of their condition was determined over long-term follow-up. Comparative accuracy of each radiological measurement category was determined by logistic regression analyses and the corresponding receiver operating characteristic (ROC) curve. A predictive model of IIS progression using these measurements was then created. RESULTS: All three radiological measurement categories were predictive of IIS progression. However, on pairwise comparison of ROC curves and multivariate analysis, the index Cobb angle proved the most significant predictor of curve progression. Using the index Cobb angle only, a predictive model of curve progression achieved an accuracy of 81.18% with a cut-off Cobb angle of 34.5° found to be the optimal threshold to discriminate a progressive from resolving curve. CONCLUSION: Of the three analysed index radiological parameters commonly used by surgeons in the prognosis of IIS, we found that the Cobb angle is the most accurate predictive measure. Further, neither addition of the RVAD nor convex RVA provided significant further prognostic value in a multivariate model of progression. However, not even the Cobb angle model was accurate in all cases; emphasising caution should be applied when relying on index radiological measurements to predict IIS outcomes.

Treatment of Advanced Heart Failure-Focus on Transplantation and Durable Mechanical Circulatory Support: What Does the Future Hold?

Heart transplantation (HTx) is the treatment of choice in patients with late-stage advanced heart failure (Advanced HF). Survival rates 1, 5, and 10 years after transplantation are 87%, 77%, and 57%, respectively, and the average life expectancy is 9.16 years. However, because of the donor organ shortage, waiting times often exceed life expectancy, resulting in a waiting list mortality of around 20%. This review aims to provide an overview of current standard, recent advances, and future developments in the treatment of Advanced HF with a focus on long-term mechanical circulatory support and HTx.

In-silico assessment of the effects of right ventricular assist device on pulmonary arterial hypertension using an image based biventricular modeling framework.

Pulmonary arterial hypertension (PAH) is a heart disease that is characterized by an abnormally high pressure in the pulmonary artery (PA). While right ventricular assist device (RVAD) has been considered recently as a treatment option for the end-stage PAH patients, its effects on biventricular mechanics are, however, largely unknown. To address this issue, we developed an image-based modeling framework consisting of a biventricular finite element (FE) model that is coupled to a lumped model describing the pulmonary and systemic circulations in a closed-loop system. The biventricular geometry was reconstructed from the magnetic resonance images of two PAH patients showing different degree of RV remodeling and a normal subject. The framework was calibrated to match patient-specific measurements of the left ventricular (LV) and RV volume and pressure waveforms. An RVAD model was incorporated into the calibrated framework and simulations were performed with different pump speeds. Results showed that RVAD unloads the RV, improves cardiac output and increases septum curvature, which are more pronounced in the PAH patient with severe RV remodeling. These improvements, however, are also accompanied by an adverse increase in the PA pressure. These results suggest that the RVAD implantation may need to be optimized depending on disease progression.

Chronic Right Heart Failure: Expanding Prevalence and Challenges in Outpatient Management.

Right heart failure is caused by right heart dysfunction resulting in suboptimal stroke volume to supply the pulmonary circulation. Therapeutic developments mean that patients with acute right heart failure survive to hospital discharge and live with chronic right heart failure. Chronic right heart failure management aims to reduce afterload, optimize preload, and support contractility, with the best evidence available in vascular targeted therapy for pulmonary arterial hypertension. However, the management of chronic right heart failure relies on adapting therapies for left ventricular heart failure to the right. We review right heart failure management in the ambulatory setting and its challenges.

Pulmonary Bleeding During Right Ventricular Support After Left Ventricular Assist Device Implantation.

OBJECTIVES: Right heart failure still occurs in up to 20% of patients after implantation of a left ventricular assist device (LVAD). One treatment option for these patients is the implantation of a temporary right ventricular assist device (RVAD). Experimental data suggest that non-pulsatile perfusion of the lungs is associated with an increased rate of pulmonary hemorrhage. The aim of this study was to determine the incidence of pulmonary bleeding complications in these patients. DESIGN: Observational study. SETTING: Single center, university hospital. PARTICIPANTS: This study included patients undergoing LVAD implantation for end-stage heart failure and subsequent implantation of a temporary right ventricular support system. INTERVENTIONS: In this study, 25 patients who underwent LVAD and additional temporary RVAD implantation were screened for pulmonary bleeding complications. MEASUREMENTS AND MAIN RESULTS: The mean Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) level at the time of LVAD implantation was 2.84. All patients experienced severe right ventricular failure (tricuspid annular plane systolic excursion [TAPSE], 10.16±26.3 mm) and severe pulmonary hypertension (right atrial [RA] pressure, 56.21±15.58 mmHg). Average duration of right ventricular support was 11.12±7.20 days, with right ventricular support being administered to 14 patients for more than 7 days. Seventeen patients were weaned successfully from right ventricular support after a mean support duration of 5 days. Five patients developed pulmonary bleeding complications, diagnosed using computed tomography scan and bronchoscopy. All bleeding occurred after postoperative day 7 and was associated with RVAD flow of more than 4 L/min within 24 hours before bleeding occurred. CONCLUSIONS: The data presented in this study suggested that right ventricular support for more than 7 days and a blood flow greater than 4 L/min were associated with pulmonary bleeding complications. This should be taken into consideration when temporary right ventricular support after LVAD implantation is planned.

Model for end-stage liver disease predicts right ventricular failure in patients with left ventricular assist devices.

High rates of right ventricular failure continue to affect postoperative outcomes in patients implanted with left ventricular assist devices (LVADs). Development of right ventricular failure and implantation with right ventricular assist devices is known to be associated with significantly increased mortality. The model for end-stage liver disease (MELD) score is an effective means of evaluating liver dysfunction. We investigated the prognostic utility of postoperative MELD on post-LVAD implantation outcomes. MELD scores, demographic data, and outcomes including length of stay, survival, and postoperative right ventricular failure were collected for 256 patients implanted with continuous flow LVADs. Regression and Kaplan-Meier analyses were used to investigate the relationship between MELD and all outcomes. Increased MELD score was found to be an independent predictor of both right heart failure and necessity for RVAD implantation (OR 1.097, CI 1.040-1.158, p = 0.001; OR 1.121, CI 1.015, p = 0.024, respectively). Patients with RV failure and who underwent RVAD implantation had reduced postoperative survival compared to patients with RV dysfunction (no RV failure = 651.4 ± 609.8 days, RV failure = 392.6 ± 444.8 days, RVAD = 89.3 ± 72.8 days; p < 0.001). In conclusion, MELD can be used to reliably predict postoperative right heart failure and the necessity for RVAD implantation. Those patients with RV failure and RVADs experience significantly increased postoperative mortality compared to those without RV dysfunction.

Oxy-RVAD: rescue in pulmonary complications after LVAD implantation.

Pulmonary complications after left ventricular assist device (LVAD) implantation seldom occur; however, if present, they may prove catastrophic. An Oxy-RVAD (oxygenator in right VAD circuit) is a lifesaving technique in such cases and allows freedom of introducing and removing an oxygenator into the RVAD circuit without opening the chest and competing with LVAD flow.

Use of a single circuit to provide temporary mechanical respiratory and circulatory support in patients with LV apical thrombus and cardiogenic shock.

INTRODUCTION: Techniques to support patients with cardiogenic shock continue to improve. Patients with intracardiac thrombi pose a potential for additional complications. Novel methods of biventricular support are necessary to manage these patients. METHODS: Two patients with refractory cardiogenic shock and left ventricular apical thrombi underwent mechanical circulatory support (MCS) as a bridge to decision, with a left ventricular assist device (LVAD) and extracorporeal mechanical oxygenation (ECMO). Instead of the conventional LV apical cannulation for LVAD, the left atrium (LA) was cannulated. The LA cannula was then integrated with the ECMO circuit via a 'Y' connection to a percutaneous right atrial cannula, enabling optimal drainage of both sides into one circuit through a single CentriMag® pump and ECMO into the aorta. RESULTS: The first patient was converted to a durable LVAD and transplanted, while the second patient was explanted, after demonstrating significant LV recovery. CONCLUSION: We demonstrated the use of MCS as a bridge to decision in patients with LV thrombi, utilizing biatrial cannulation with a 'Y' connection to drain both right- and left-sided circulation through a single circuit and pump.

The ProtekDuo Cannula: A Comprehensive Review of Efficacy and Clinical Applications in Right Ventricular Failure.

Right ventricular failure (RVF) is a clinical challenge associated with various underlying acute and chronic medical conditions, necessitating diverse management strategies including mechanical circulatory support (MCS). The ProtekDuo cannula represents an important advancement in medical devices for MCS in the setting of RVF. When combined with an extracorporeal blood pump, the dual-lumen design allows for direct bypass of the RV using simultaneous drainage and return of blood using percutaneous, single-site access. Studies have reported favorable outcomes with the ProtekDuo cannula and low device-related complications, but comparative studies with other MCS devices are limited. Still, the ProtekDuo cannula has numerous advantages; however, it is not without challenges, and opportunities for further research exist. The ProtekDuo cannula holds significant potential for future advancements in the field of MCS, offering promising solutions for RVF management.

Glenn shunt as a rescue strategy for acute right ventricular failure after right ventricular myocardial infarction.

We present the case of a 52-year-old woman with cardiogenic shock and refractory right ventricular failure due to spontaneous dissection of the right coronary artery. She remained dependent on mechanical support for several weeks. Both a right ventricular assist device implant and a bidirectional cavopulmonary anastomosis were explored as long-term support options. A history of malignancy and possible right ventricular functional recovery resulted in a decision in favour of the bidirectional cavopulmonary anastomosis and concomitant tricuspid valve annuloplasty. Postoperatively her clinical condition improved significantly, and she could be discharged home. Echocardiography showed normalization of right ventricular dimensions and slight improvement of right ventricular function.

Use of a Percutaneous Right Ventricular Assist Device to Manage Right Ventricular Failure in Inferior STEMIs.

Acute right heart failure is a complication of inferior ST-elevation myocardial infarctions. Given the further hemodynamic instability that results from right-sided failure, a treatment option is needed to help bridge toward cardiac recovery. We present a case of using a right ventricular assist device in a patient who had marked improvement in cardiac function after an instance of acute right heart failure.

Synchronous PIV measurements of a self-powered blood turbine and pump couple for right ventricle support.

A blood turbine-pump system (iATVA), resembling a turbocharger was proposed as a mechanical right-heart assist device without external drive power. In this study, the iATVA system is investigated with particular emphasis on the blood turbine flow dynamics. A time-resolved 2D particle image velocimetry (PIV) set-up equipped with a beam splitter and two high speed cameras, allowed simultaneous recordings from both the turbine and pump impellers at 7 different phased-locked instances. The iATVA prototype is 3D printed using an optically clear resin following our earlier PIV protocols. Results showed that magnetically coupled impellers operated synchronously. As the turbine flow rate increased from 1.6 to 2.4 LPM, the rotational speed and relative inlet flow angle increase from 630 to 900 rpm, and 38 to 55% respectively. At the trailing edges, backflow region spanned 3/5 of the total passage outlet flow, and an extra leakage flow was observed at the leading edge. For this early turbine design, approximately, 75% of the turbine blade passage was not contributing to the impulse operation mode. The maximum non-wall shear rate was ~ 2288 s-1 near to the inlet exit, which is significantly lower than the commercial blood pumps, encouraging further research and blood experiments of this novel concept. Experimental results will improve the hydrodynamic design of the turbine impeller and volute regions and will be useful in computational fluid dynamics validation studies of similar passive devices.

Acute right atrial thrombus formation after extracorporeal life support removal during LVAD-implantation.

A 58-year-old male underwent LVAD-Implantation after ECLS explantation. After removal of ECLS (A) transesophageal echocardiography revealed thrombus in the inferior vena cava (B) and right atrium (C). The thrombus was removed with a second pump run including RVAD-Implantation. (D) The diameter of thrombus formations was 6 × 1 cm and 5 × 1.5 cm.

The protekduo cannula for acute right ventricular support in thyrotoxicosis.

A 25-year-old female was presented with acute right heart failure (aRHF) and cardiogenic shock secondary to thyrotoxicosis with concomitant acute respiratory failure. A ProtekDuo cannula was placed to provide temporary percutaneous right ventricular assistance and extracorporeal membrane oxygenation (ECMO) in venopulmonary (V-P) configuration, which provided both decompression of the right ventricle (RV) and oxygenation. With treatment of the underlying thyrotoxicosis, the RV function improved and respiratory failure resolved. She was discharged home in good condition. This case details alternative ECMO management with ProtekDuo compared to the gold standard of venoarterial (V-A) ECMO.

Interventricular Septal Hematoma Complicating Ventricular Assist Device Placement in an Infant: Case Report and Review of the Literature.

Interventricular septal hematoma is a rare and life-threatening complication of pediatric cardiac surgery. Commonly seen following ventricular septal defect repair, it has also been associated with ventricular assist device (VAD) placement. Although conservative management is usually successful, operative drainage of interventricular septal hematoma occurring in pediatric patients undergoing VAD implantation should be considered.