The risk of right ventricular failure with current continuous-flow left ventricular assist devices

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.

Effect of Anesthesia Induction on Cardiac Hemodynamics in Patients Undergoing Durable Left Ventricular Assist Device Implantation: The EACH-LVAD Study

Right ventricular (RV) dysfunction is common after left ventricular assist device (LVAD) implantation leading to clinical right heart failure (RHF) associated with worsened survival and quality of life. It is likely that intraoperative events such as anesthesia induction play a role in the development or unmasking of RV dysfunction in addition to known effects from hemodynamic changes that occur after LVAD implantation. The EACH-LVAD Study is a prospective, single-center, single-arm, observational cohort study of adult patients with advanced heart failure undergoing durable LVAD implantation with standard anesthesia induction. Intraoperative RV hemodynamics via central venous pressure, mean pulmonary artery pressure, pulmonary artery pulsatility index, and vasoactive-inotropic score (a simple weighted summation of standardized drug doses) and echocardiographic parameters (RV fractional area change, RV area in diastole, RV basal diameter, septum position, RV function, tricuspid regurgitation) were measured and compared at prespecified timepoints, including postinduction. Postoperative clinical RHF was determined based on published definitions. Forty-two patients receiving a first-time LVAD were included between September 2017 and March 2019. Propofol-based induction was used in 31 patients and etomidate-based induction in eight patients. A significant increase in central venous pressure (CVP; p < 0.001), mean pulmonary artery pressure (mPAP; p < 0.001), and vasoactive inotropic score (VIS; p < 0.001) with associated decrease in pulmonary artery pulsatility index (PAPi; p < 0.001) was observed. Right ventricular function worsened throughout. Right heart failure occurred in 70% of patients. Propofol-based induction was not associated with a higher risk of RHF (relative risk [RR], 1.01 [95% confidence interval {CI}, 0.64-1.61]). The EACH-LVAD study demonstrates an effect of anesthesia induction on worsened RV hemodynamics and echocardiographic changes which may have an effect on the development of RHF.

Safety and feasibility of hemodynamic pulmonary artery pressure monitoring using the CardioMEMS device in LVAD management

BACKGROUND

There is a clinical need for additional remote tools to improve left ventricular assist device (LVAD) patient management. The aim of this pilot concept study was to assess the safety and feasibility of optimizing patient management with add-on remote hemodynamic monitoring using the CardioMEMS in LVAD patients during different treatment stages.

METHODS

Ten consecutive patients accepted and clinically ready for (semi-) elective HeartMate 3 LVAD surgery were included. All patients received a CardioMEMS to optimize filling pressure before surgery. Patients were categorized into those with normal mean pulmonary artery pressure (mPAP) (≤25 mmHg, n = 4) or elevated mPAP (>25 mmHg, n = 6), and compared to a historical cohort (n = 20). Endpoints were CardioMEMS device safety and a combined endpoint of all-cause mortality, acute kidney injury, renal replacement therapy and/or right ventricular failure at 1-year follow-up. Additionally, we investigated hospital-free survival and improvement in quality of life (QoL) and exercise tolerance.

RESULTS

No safety issues or signal interferences were observed. The combined endpoint occurred in 60% of historical controls, 0% in normal and 83% in elevated mPAP group. Post-discharge, the hospital-free survival was significantly better, and the QoL improved more in the normal compared to the elevated mPAP group.

CONCLUSION

Remote hemodynamic monitoring in LVAD patients is safe and feasible with the CardioMEMS, which could be used to identify patients at elevated risk of complications as well as optimize patient management remotely during the out-patient phase with less frequent hospitalizations. Larger pivotal studies are warranted to test the hypothesis generated from this concept study.

Remote hemodynamic guidance before and after left ventricular assist device implantation: short-term results from the HEMO-VAD pilot study

Aim: We aimed to assess the safety and feasibility of using CardioMEMS monitoring in patients before and after left ventricular assist device (LVAD) surgery. Patients & methods: Ten patients accepted for elective LVAD surgery were included, received a CardioMEMS at baseline and were categorized based on mean pulmonary artery pressure (mPAP) ≤25 mmHg (n = 4) or mPAP >25 mmHg [n = 6]) before LVAD surgery. Results: The combined end point of all-cause mortality, acute kidney injury and/or renal replacement therapy, and right ventricular failure occurred more often in patients with an mPAP >25 mmHg (83 vs 0%, p = 0.017). Conclusion: This pilot study demonstrates that combining CardioMEMS monitoring with LVAD therapy is safe and generates the hypothesis that patients with an mPAP >25 mmHg before LVAD surgery identify a very high-risk group for adverse clinical outcomes.

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.

Defibrillator-Heart Pump: An Implantable Ventricular Assist Device With Integrated Defibrillator Component-The First In Vitro Testing

Left ventricular assist devices (LVADs) are an important therapeutic option for patients with end-stage heart failure waiting for heart transplantation or in older patients as definite therapy for heart failure. Interestingly, about 62% of patients receiving LVADs do not have an automatic implantable cardioverter-defibrillator (AICD) at the time of implantation, although these patients have increased risk of being confronted with dangerous arrhythmia. Therefore, an LVAD system including AICD function is a reasonable alternative for such heart failure patients thereby avoiding a second surgical intervention for AICD implantation. In this article, a newly developed system including LVAD and AICD function is introduced, and we also report its first in vitro testing.

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.

Approach to Complications of Ventricular Assist Devices: A Clinical Review for the Emergency Provider

BACKGROUND

Heart failure is a major public health problem in the United States. Increasingly, patients with advanced heart failure that fail medical therapy are being treated with implanted ventricular assist devices (VADs).

OBJECTIVE

This review provides an evidence-based summary of the current data for the evaluation and management of implanted VAD complications in an emergency department context.

DISCUSSION

With a prevalence of >5.8 million individuals and >550,000 new cases diagnosed each year, heart failure is a major public health problem in the United States. Increasingly, patients with advanced heart failure that fail medical therapy are being treated with implanted VADs. As the prevalence of patients with VADs continues to grow, they will sporadically present to the emergency department, regardless of whether the facility is a designated VAD center. As a result, all emergency physicians must be familiar with the basic principles of VAD function, as well as the diagnosis and initial management of VAD-related complications. In this review, we address these topics, with a focus on contemporary third-generation continuous flow VADs. This review will help supplement the critical care skills of emergency physicians in managing this complex patient population.

CONCLUSIONS

The cornerstone of managing the unstable VAD patient is rapid initiation of high-quality supportive care and recognition of device-related complications, as well as the identification and use of specialist VAD teams and other resources for support. Emergency physicians must understand VADs so that they may optimally manage these complex patients.

Design and rationale of haemodynamic guidance with CardioMEMS in patients with a left ventricular assist device: the HEMO-VAD pilot study

AIMS

We aim to study the feasibility and clinical value of pulmonary artery pressure monitoring with the CardioMEMS™ device in order to optimize and guide treatment in patients with a HeartMate 3 left ventricular assist device (LVAD).

METHODS AND RESULTS

In this single-centre, prospective pilot study, we will include 10 consecutive patients with New York Heart Association Class IIIb or IV with Interagency Registry for Mechanically Assisted Circulatory Support Classes 2-5 scheduled for implantation of a HeartMate 3 LVAD. Prior to LVAD implantation, patients will receive a CardioMEMS sensor, for daily pulmonary pressure readings. The haemodynamic information provided by the CardioMEMS will be used to improve haemodynamic status prior to LVAD surgery and optimize the timing of LVAD implantation. Post-LVAD implantation, the haemodynamic changes will be assessed for additive value in detecting potential complications in an earlier stage (bleeding and tamponade). During the outpatient clinic phase, we will assess whether the haemodynamic feedback can optimize pump settings, detect potential complications, and further tailor the clinical management of these patients.

CONCLUSIONS

The HEMO-VAD study is the first prospective pilot study to explore the safety and feasibility of using CardioMEMS for optimization of LVAD therapy with additional (remote) haemodynamic information.