Use of percutaneous mechanical circulatory support for right ventricular failure

BACKGROUND

Utilization of right ventricular mechanical circulatory support (RV-MCS) devices has been limited by a lack of recognition of RV failure as well as a lack of availability and experience with RV-MCS.

AIMS

We report a single-center experience with the use of percutaneous RV-MCS and report predictors of adverse outcomes.

METHODS

This was a single-center retrospective cohort study. Data from consecutive patients who received RV-MCS for any indication between June 2015 and January 2022 were included. Data on baseline comorbidities, hemodynamics, and laboratory values were collected. The primary outcome was in-hospital mortality analyzed as a logistic outcome in a multivariable model. These variables were further ranked by their predictive value.

RESULTS

Among 58 consecutive patients enrolled, the median age was 66 years, 31% were female and 53% were white. The majority of the patients (48%) were hospitalized for acute on chronic heart failure. The majority of the patients were SCAI SHOCK Stage D (67%) and 34 (64%) patients had MCS placed within 24 h of the onset of shock. Before placement of RV-MCS, median central venous pressure (CVP) and RV stroke work index were 20 mmHg and 8.9 g m/m2, respectively. Median serum lactate was 3.5 (1.6, 6.2) mmol/L. Impella RP was implanted in 50% and ProtekDuo in the remaining 50%. Left ventricular MCS was concomitantly used in 66% of patients. Twenty-eight patients (48.3%) died. In these patients, median serum lactate was significantly higher (4.1 [2.3, 13.0] vs. 2.2 [1.4, 4.0]  mmol/L, p = 0.007) and a trend toward higher median CVP (24 [18, 31] vs. 19 [14, 24] mmHg, p = 0.052). In the multivariable logistic model, both serum lactate and CVP before RV-MCS placement were independent predictors of in-hospital mortality. Serum lactate had the highest predictive value.

CONCLUSION

In our real-world cohort, 52% of patients treated with RV-MCS survived their index hospitalization. Serum lactate at presentation and CVP were the strongest predictors of in-hospital mortality.

Treatment Strategies and Outcomes of Right Ventricular Failure Post Left Ventricular Assist Device Implantation: An INTERMACS Analysis

Right heart failure (RHF) management after left ventricular assist device (LVAD) implantation includes inotropes, right ventricular mechanical support, and heart transplantation. The purpose of this study is to compare different RHF treatment strategies in patients with a magnetically levitated centrifugal LVAD. A total of 6,632 Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) patients from 2013 to 2020 were included. Of which, 769 (69.6%) patients (group 1) were supported with inotropes (≥14 days post-LVAD implantation), 233 (21.1%) patients (group 2) were supported with temporary right ventricular assist device (RVAD) that was implanted during LVAD implant, 77 (7.0%) patients (group 3) with durable centrifugal RVAD implanted during the LVAD implant, and 26 (2.4%) patients (group 4) were supported with RVAD (temporary or permanent), which was implanted at a later stage. Groups 1 and 4 had higher survival rates in comparison with group 2 (hazard ratio [HR] = 0.513, 95% confidence intervals [CIs] = 0.402-0.655, p < 0.001, versus group 1) and group 3 (HR = 0.461, 95% CIs = 0.320-0.666, p < 0.001, versus group 1). Patients in group 3 showed higher heart transplantation rates at 12 and 36 months as compared with group 1 (40.4% and 46.6% vs. 21.9% and 37.4%, respectively), group 2 (40.4% and 46.6% vs. 25.8% and 39.3%, respectively), and group 4 (40.4% and 46.6% vs. 3.8% and 12.0%, respectively). Severe RHF post-LVAD is associated with poor survival. Patients with LVAD who during the perioperative period are in need of right ventricular temporary or durable mechanical circulatory support constitute a group at particular risk. Improvement of devices tailored for right ventricular support is mandatory for further evolution of the field.

The Future of Durable Mechanical Circulatory Support: Emerging Technological Innovations and Considerations to Enable Evolution of the Field

The field of durable mechanical circulatory support (MCS) has undergone an incredible evolution over the past few decades, resulting in significant improvements in longevity and quality of life for patients with advanced heart failure. Despite these successes, substantial opportunities for further improvements remain, including in pump design and ancillary technology, perioperative and postoperative management, and the overall patient experience. Ideally, durable MCS devices would be fully implantable, automatically controlled, and minimize the need for anticoagulation. Reliable and long-term total artificial hearts for biventricular support would be available; and surgical, perioperative, and postoperative management would be informed by the individual patient phenotype along with computational simulations. In this review, we summarize emerging technological innovations in these areas, focusing primarily on innovations in late preclinical or early clinical phases of study. We highlight important considerations that the MCS community of clinicians, engineers, industry partners, and venture capital investors should consider to sustain the evolution of the field.

Cardiogenic shock in a young woman with SCAD: The importance of early access to VA-ECMO in the community

Spontaneous coronary artery dissection (SCAD) is a common cause of myocardial infarction in young and middle-aged women. Patients with SCAD present rarely with hemodynamic collapse and cardiogenic shock, requiring immediate resuscitation and mechanical circulatory support. Percutaneous mechanical circulatory support may serve as a bridge to recovery, decision or heart transplantation. We present a case of a young woman with SCAD of the left main coronary artery, presenting with ST-elevation myocardial infarction, cardiac arrest and cardiogenic shock. She was stabilized emergently with Impella and early escalation with extracorporeal membrane oxygenation (ECPELLA) at a non-surgical community hospital. Despite revascularization with percutaneous coronary intervention (PCI), her left ventricular recovery was poor, and ultimately required cardiac transplantation on day 5 of her presentation.

Aspirin and Hemocompatibility Events With a Left Ventricular Assist Device in Advanced Heart Failure: The ARIES-HM3 Randomized Clinical Trial

IMPORTANCE

Left ventricular assist devices (LVADs) enhance quality and duration of life in advanced heart failure. The burden of nonsurgical bleeding events is a leading morbidity. Aspirin as an antiplatelet agent is mandated along with vitamin K antagonists (VKAs) with continuous-flow LVADs without conclusive evidence of efficacy and safety.

OBJECTIVE

To determine whether excluding aspirin as part of the antithrombotic regimen with a fully magnetically levitated LVAD is safe and decreases bleeding.

DESIGN, SETTING, and PARTICIPANTS

This international, randomized, double-blind, placebo-controlled study of aspirin (100 mg/d) vs placebo with VKA therapy in patients with advanced heart failure with an LVAD was conducted across 51 centers with expertise in treating patients with advanced heart failure across 9 countries. The randomized population included 628 patients with advanced heart failure implanted with a fully magnetically levitated LVAD (314 in the placebo group and 314 in the aspirin group), of whom 296 patients in the placebo group and 293 in the aspirin group were in the primary analysis population, which informed the primary end point analysis. The study enrolled patients from July 2020 to September 2022; median follow-up was 14 months.

Intervention

Patients were randomized in a 1:1 ratio to receive aspirin (100 mg/d) or placebo in addition to an antithrombotic regimen.

MAIN OUTCOMES AND MEASURES

The composite primary end point, assessed for noninferiority (-10% margin) of placebo, was survival free of a major nonsurgical (>14 days after implant) hemocompatibility-related adverse events (including stroke, pump thrombosis, major bleeding, or arterial peripheral thromboembolism) at 12 months. The principal secondary end point was nonsurgical bleeding events.

RESULTS

Of the 589 analyzed patients, 77% were men; one-third were Black and 61% were White. More patients were alive and free of hemocompatibility events at 12 months in the placebo group (74%) vs those taking aspirin (68%). Noninferiority of placebo was demonstrated (absolute between-group difference, 6.0% improvement in event-free survival with placebo [lower 1-sided 97.5% CI, -1.6%]; P < .001). Aspirin avoidance was associated with reduced nonsurgical bleeding events (relative risk, 0.66 [95% confidence limit, 0.51-0.85]; P = .002) with no increase in stroke or other thromboembolic events, a finding consistent among diverse subgroups of patient characteristics.

CONCLUSIONS AND RELEVANCE

In patients with advanced heart failure treated with a fully magnetically levitated LVAD, avoidance of aspirin as part of an antithrombotic regimen, which includes VKA, is not inferior to a regimen containing aspirin, does not increase thromboembolism risk, and is associated with a reduction in bleeding events.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04069156.

Durable Mechanical Circulatory Support: JACC Scientific Statement

Despite advances in medical therapy for patients with stage C heart failure (HF), survival for patients with advanced HF is <20% at 5 years. Durable left ventricular assist device (dLVAD) support is an important treatment option for patients with advanced HF. Innovations in dLVAD technology have reduced the risk of several adverse events, including pump thrombosis, stroke, and bleeding. Average patient survival is now similar to that of heart transplantation at 2 years, with 5-year dLVAD survival now approaching 60%. Unfortunately, greater adoption of dLVAD therapy has not been realized due to delayed referral of patients to advanced HF centers, insufficient clinician knowledge of contemporary dLVAD outcomes (including gains in quality of life), and deprioritization of patients with dLVAD support waiting for heart transplantation. Despite these challenges, novel devices are on the horizon of clinical investigation, offering smaller size, permitting less invasive surgical implantation, and eliminating the percutaneous lead for power supply.

Patients hospitalized with acute heart failure, worsening renal function, and persistent congestion are at high risk for adverse outcomes despite current medical therapy

INTRODUCTION

Approximately 1/3 of patients with acute decompensated heart failure (ADHF) are discharged with persistent congestion. Worsening renal function (WRF) occurs in approximately 50% of patients hospitalized for ADHF and the combination of WRF and persistent congestion are associated with higher risk of mortality and HF readmissions.

METHODS

We designed a multicenter, prospective registry to describe current treatments and outcomes for patients hospitalized with ADHF complicated by WRF (defined as a creatinine increase ≥0.3 mg/dL) and persistent congestion at 96 h. Study participants were followed during the hospitalization and through 90-day post-discharge. Hospitalization costs were analyzed in an economic substudy.

RESULTS

We enrolled 237 patients hospitalized with ADHF, who also had WRF and persistent congestion. Among these, the average age was 66 ± 13 years and 61% had a left ventricular ejection fraction (LVEF) ≤ 40%. Mean baseline creatinine was 1.7 ± 0.7 mg/dL. Patients with persistent congestion had a high burden of clinical events during the index hospitalization (7.6% intensive care unit transfer, 2.1% intubation, 1.7% left ventricular assist device implantation, and 0.8% dialysis). At 90-day follow-up, 33% of patients were readmitted for ADHF or died. Outcomes and costs were similar between patients with reduced and preserved LVEF.

CONCLUSIONS

Many patients admitted with ADHF have WRF and persistent congestion despite diuresis and are at high risk for adverse events during hospitalization and early follow-up. Novel treatment strategies are urgently needed for this high-risk population.

HFSA Expert Consensus Statement on the Medical Management of Patients on Durable Mechanical Circulatory Support

The medical management of patients supported with durable continuous flow left ventricular assist device (LVAD) support encompasses pharmacologic therapies administered in the preoperative, intraoperative, postoperative and chronic LVAD support stages. As patients live longer on LVAD support, the risks of LVAD-related complications and progression of cardiovascular and other diseases increase. Using existing data from cohort studies, registries, randomized trials and expert opinion, this Heart Failure Society of America Consensus Document on the Medical Management of Patients on Durable Mechanical Circulatory Support offers best practices on the management of patients on durable MCS, focusing on pharmacological therapies administered to patients on continuous flow LVADs. While quality data in the LVAD population are few, the utilization of guideline directed heart failure medical therapies (GDMT) and the importance of blood pressure management, right ventricular preload and afterload optimization, and antiplatelet and anticoagulation regimens are discussed. Recommended pharmacologic regimens used to mitigate or treat common complications encountered during LVAD support, including arrhythmias, vasoplegia, mucocutaneous bleeding, and infectious complications are addressed. Finally, this document touches on important potential pharmacological interactions from anti-depressants, herbal and nutritional supplements of relevance to providers of patients on LVAD support.

Amiodarone Use and All-Cause Mortality in Patients With a Continuous-Flow Left Ventricular Assist Device

Background

Atrial and ventricular arrhythmias are commonly encountered in patients with advanced heart failure, with amiodarone being the most commonly used antiarrhythmic drug in continuous‐flow left ventricular assist device (CF‐LVAD) recipients. The purpose of this study was to assess the impact of amiodarone use on long‐term all‐cause mortality in ptients with a CF‐LVAD.

Methods and Results

A retrospective multicenter study of CF‐LVAD was conducted at 5 centers including all CF‐LVAD implants from 2007 to 2015. Patients were stratified based on pre–CF‐LVAD implant amiodarone use. Additional use of amiodarone after CF‐LVAD implantation was also evaluated. Primary outcome was all‐cause mortality during long‐term follow‐up. Kaplan‐Meier curves were used to assess survival outcomes. Multivariable Cox regression was used to identify predictors of outcomes. Propensity matching was done to address baseline differences. A total of 480 patients with a CF‐LVAD (aged 58±13 years, 81% men) were included. Of these, 170 (35.4%) were on chronic amiodarone therapy at the time of CF‐LVAD implant, and 310 (64.6%) were not on amiodarone. Rate of all‐cause mortality over the follow‐up period was 32.9% in the amiodarone group compared with 29.6% in those not on amiodarone (P=0.008). Similar results were noted in the propensity‐matched group (log‐rank, P=0.04). On multivariable Cox regression analysis, amiodarone use at baseline was independently associated with all‐cause mortality (hazard ratio, 1.68 [95% CI, 1.1–2.5]; P=0.01).

Conclusions

Amiodarone use was associated with significantly increased rates of all‐cause mortality in CF‐LVAD recipients. Earlier interventions for arrhythmias to avoid long‐term amiodarone exposure may improve long‐term outcomes in CF‐LVAD recipients and needs further study.

Quality of Life Metrics in LVAD Patients after Hemocompatibility-Related Adverse Events

BACKGROUND

Hemocompatibility-related adverse events (HRAE) negatively influence survival. However, no study has examined the impact of these events on health-related quality of life (HRQOL) and functional outcomes following continuous flow left ventricular assist device implantation (CF-LVAD). We assessed the impact of HRAE events on HRQOL and hypothesized that HRAE's adversely impact HRQOL and functional outcomes.

METHODS

INTERMACS database identified patients undergoing primary CF-LVAD implantation from 2008 to 2017. HRAEs included stroke, non-surgical bleeding, hemolysis, and pump thrombosis and were identified as defined in the literature. HRAEs were further stratified as Tier 1-2 and disabling stroke events. Time-series analysis was executed for HRAE patients with values pre-HRAE, post-HRAE, and closest to 12 month follow up. Local polynomial regression curves modeling individual patients were superimposed into "spaghetti" plots.

RESULTS

All HRQOL and functional metrics improved in patients over time, despite HRAE complication. However, these patient metrics were significantly reduced compared to the non-HRAE cohort (Table 2). Advanced data visualization techniques noted decline after experiencing an HRAE with a subsequent recovery to baseline levels or higher (Figure1-4). 6MWT was noted to be most affected in the post-HRAE period but recovered similar to other metrics (Table 3).

CONCLUSIONS

The burden of HRAE following CF-LVAD implantation did not negatively impact quality of life. However, 6-minute walk test did not increase in the post-HRAE period in all HRAE patients. Improvement of heart failure symptoms after CF-LVAD coupled with optimal management following HRAE act to preserve enhanced quality of life.

HVAD to HeartMate 3 left ventricular assist device exchange: Best practices recommendations

The HeartWare HVAD System (Medtronic) is a durable implantable left ventricular assist device that has been implanted in approximately 20,000 patients worldwide for bridge to transplant and destination therapy indications. In December 2020, Medtronic issued an Urgent Medical Device Communication informing clinicians of a critical device malfunction in which the HVAD may experience a delay or failure to restart after elective or accidental discontinuation of pump operation. Moreover, evolving retrospective comparative effectiveness studies of patients supported with the HVAD demonstrated a significantly higher risk of stroke and all-cause mortality when compared with a newer generation of a commercially available durable left ventricular assist device. Considering the totality of this new information on HVAD performance and the availability of an alternate commercially available device, Medtronic halted the sale and distribution of the HVAD System in June 2021. The decision to remove the HVAD from commercial distribution now requires the use of the HeartMate 3 left ventricular assist system (Abbott, Inc) if a patient previously implanted with an HVAD requires a pump exchange. The goal of this document is to review important differences in the design of the HVAD and HeartMate 3 that are relevant to the medical management of patients supported with these devices, and to assess the technical aspects of an HVAD-to-HeartMate 3 exchange. This document provides the best available evidence that supports best practices.

Outcomes, Temporal Trends, and Resource Utilization in Ischemic versus Nonischemic Cardiogenic Shock

Cardiogenic shock (CS) is associated with significant morbidity and mortality. Differentiating the etiologic factors driving CS has epidemiological significance and aids in optimization of therapeutic strategies, prognostication, and resource utilization. The aim herein is to investigate the epidemiology and clinical outcomes of CS in those with ischemic and nonischemic CS etiologies. Using International Classification of Diseases codes, we queried the national inpatient sample for CS hospitalization from 2007 to 2018 and divided the study sample into cohorts of ischemic (I-CS) and nonischemic cardiogenic shock (NI-CS). We then compared the primary outcome of in-hospital mortality between these 2 cohorts. Two groups of secondary outcomes (clinical and procedural) were also assessed between the 2 cohorts. CS was present in 557,860 hospitalizations; 84% of these were I-CS and 15.8% NI-CS. Patients with I-CS were older, more commonly males, with more risk factors for coronary artery disease (P < 0.05). NI-CS had higher prevalence of preexisting systolic heart failure and atrial fibrillation. The in-hospital mortality was significantly higher in patients with I-CS (32.2% vs. 29.5%, adjusted odds ratio 1.10, P < 0.001). Frequencies of acute ischemic stroke, mechanical ventilation, ventricular arrhythmias, and vascular complications were higher in I-CS versus NI-CS, while acute kidney injury and acute liver failure were more common in NI-CS (P < 0.05). The use of mechanical circulatory support devices was higher in the I-CS group. In conclusion, patients with I-CS comprise the vast majority of CS and are associated with higher mortality and higher resource utilization. Conversely, patients with NI-CS appear to have higher survival but with a higher prevalence of end-organ dysfunction.

Outcomes of Durable Mechanical Circulatory Support in Myocarditis: Analysis of the International Society for Heart and Lung Transplantation Registry for Mechanically Assisted Circulatory Support Registry

Myocarditis can be refractory to medical therapy and require durable mechanical circulatory support (MCS). The characteristics and outcomes of these patients are not known. We identified all patients with clinically-diagnosed or pathology-proven myocarditis who underwent mechanical circulatory support in the International Society for Heart and Lung Transplantation Registry for Mechanically Assisted Circulatory Support registry (2013-2016). The characteristics and outcomes of these patients were compared to those of patients with nonischemic cardiomyopathy (NICM). Out of 14,062 patients in the registry, 180 (1.2%) had myocarditis and 6,602 (46.9%) had NICM. Among patients with myocarditis, duration of heart failure was <1 month in 22%, 1-12 months in 22.6%, and >1 year in 55.4%. Compared with NICM, patients with myocarditis were younger (45 vs. 52 years, P < 0.001) and were more often implanted with Interagency Registry for Mechanically Assisted Circulatory Support profile 1 (30% vs. 15%, P < 0.001). Biventricular mechanical support (biventricular ventricular assist device [BIVAD] or total artificial heart) was implanted more frequently in myocarditis (18% vs. 6.7%, P < 0.001). Overall postimplant survival was not different between myocarditis and NICM (left ventricular assist device: P = 0.27, BIVAD: P = 0.50). The proportion of myocarditis patients that have recovered by 12 months postimplant was significantly higher in myocarditis compared to that of NICM (5% vs. 1.7%, P = 0.0003). Adverse events (bleeding, infection, and neurologic dysfunction) were all lower in the myocarditis than NICM. In conclusion, although myocarditis patients who receive durable MCS are sicker preoperatively with higher needs for biventricular MCS, their overall MCS survival is noninferior to NICM. Patients who received MCS for myocarditis are more likely than NICM to have MCS explanted due to recovery, however, the absolute rates of recovery were low.

Exploring Physician Perceptions of the 2018 United States Heart Transplant Allocation System

BACKGROUND

After the implementation of the 2018 US heart transplant allocation system, the experience and perceptions of heart transplant clinicians have not been well-cataloged.

METHODS AND RESULTS

This web-based survey of both heart failure cardiologists and surgeons examined physician perspectives about the policy changes and whether the system is meeting its intended goals. The majority of participants (94%, n = 113) responded that the 2018 heart allocation system requires modification. Eighty-four percent reported using more temporary mechanical circulatory support to achieve higher status and 86% were concerned about the change in physician behavior and practices under the new system.

CONCLUSIONS

Suggestions for possible improvement included higher status for patients on durable left ventricular assist device support, changes to criteria for status 2, modification of status exceptions, and advocacy for a heart allocation score.

Does Size Matter for Female Continuous-flow LVAD Recipients? A Translational Approach to a Decade Long Question

Females have increased risk of right-ventricular failure (RVF) and 3 month mortality after left-ventricular assist device (LVAD) implantation. In this translational study, we tested the hypothesis that sex differences in outcomes are driven by pump-induced LV size-volume mismatch, due to a negative impact on interventricular septal (IVS) interdependence. Adult continuous-flow LVAD recipients from the International Society For Heart And Lung Transplantation Mechanically Assisted Circulatory Support registry (n = 15,498) were studied to determine association of female sex with outcomes of 3 month mortality and RVF. Female sex was associated with smaller preimplant left-ventricular end-diastolic diameter (6.5 vs. 6.9 cm, p < 0.001), increased 3 month mortality (odds ratio [OR]: 1.42, p < 0.001) and RVF (OR: 1.18, p = 0.005). Smaller left-ventricular end-diastolic diameter was associated with worse outcomes after LVAD implantation (OR for mortality: 1.20, p < 0.001; RVF: 1.09, p < 0.001), and attenuated the association of female sex with these outcomes. In test bench heart phantoms (n = 4), the IVSs of smaller hearts demonstrated abnormal leftward shift earlier than larger hearts (volume change at IVS shift: 40 [95% confidence interval: 30-52] vs. 50 [95% confidence interval: 48-69] ml). Smaller LV size partially mediates worse post-LVAD outcomes for female patients, due to lower volume thresholds for adverse IVS shifting.

Mechanical circulatory support in acute myocardial infarction and cardiogenic shock: Challenges and importance of randomized control trials

BACKGROUND

Acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) is associated with significant morbidity and mortality.

METHODS

We provide an overview of previously conducted studies on the use of mechanical circulatory support (MCS) devices in the treatment of AMI-CS and difficulties which may be encountered in conducting such trials in the United States.

RESULTS

Well powered randomized control trials are difficult to conduct in a critically ill patient population due to physician preferences, perceived lack of equipoise and challenges obtaining informed consent.

CONCLUSIONS

With growth in utilization of MCS devices in patients with AMI-CS, efforts to perform well-powered, randomized control trials must be undertaken.

Left atrial venous arterial extracorporeal membrane oxygenation for biventricular failure in cardiogenic shock

Background

Cardiogenic shock complicated by biventricular (BIV) heart failure is associated with high mortality. Venous-arterial extra-corporeal membrane oxygenation is limited by the increase of left ventricular (LV) afterload. Complex configurations of paired circulatory support devices have been used with mixed results due to vascular access complications. One way to simply vascular access is to place a transseptal cannula under echocardiographic guidance with a long fenestrated segment enabling simultaneous left and right sided unloading known as left-atrial venous arterial (LAVA) ECMO.

Purpose

We aimed to review the safety and outcomes of LAVA ECMO utilized for shock at our institution.

Methods

Retrospective analysis of our Hospital Cath Lab Database yielded 6 patients undergoing LAVA-ECMO for shock from 7/2020–3/2021. Patient characteristics, procedural data and outcomes were analyzed. Variables are either expressed as proportions or medians (Interquartile range; IQR).

Results

Median age was 55.5 years (IQR, 51–61) and most patients were men (83.3%). Median baseline LV ejection fraction was 38% (IQR, 23–56%) and all had right ventricular dysfunction. 4/6 (66.7%) had severe valvular dysfunction including aortic regurgitation (2/6), mitral regurgitation (2/6) and mitral stenosis (1/6). One patient had a LV thrombus and hemodynamics necessitated LV unloading. Intracardiac echocardiography was used to guide the transseptal puncture in 5/6 (83%). Transesophageal echocardiography was used in one case. Procedural outcomes and hemodynamic variables are outlined in Tables 1 and 2 consecutively. One case of limb ischemia resulted from an embolus in the contralateral limb. LAVA-ECMO bridged 83% of patients to valve replacement, durable ventricular support or heart transplant (Table 1).

Conclusions

LAVA-ECMO provides BIV support with a single circuit and successfully bridged patients without direct complications. Given the safety, efficacy and simplified configuration of LAVA-ECMO, prospective studies are indicated.

Funding Acknowledgement

Type of funding sources: None.

Randomized Trials Are Needed for Transcatheter Mitral Valve Replacement

Transcatheter mitral valve replacement (TMVR) is a new therapy for treating symptomatic mitral regurgitation (MR) and stenosis. The proposed benefit of TMVR is the predictable, complete elimination of MR, which is less certain with transcatheter repair technologies such as TEER (transcatheter edge-to-edge repair). The potential benefit of MR elimination with TMVR needs to be rigorously evaluated against its risks which include relative procedural invasiveness, need for anticoagulation, and chronic structural valve deterioration. Randomized controlled trials (RCTs) are a powerful method for evaluating the safety and effectiveness of TMVR against current standard of care transcatheter therapies, such as TEER. RCTs not only help with the assessment of benefits and risks, but also with policies for determining operator or institutional requirements, resource utilization, and reimbursement. In this paper, the authors provide recommendations and considerations for designing pivotal RCTs for first-in-class TMVR devices.

The genetics of cardiac amyloidosis

Heritable cardiac amyloidosis (CA) is an underrecognized cause of morbidity and mortality in the USA. It results from the accumulation of the misfolded protein transthyretin within the myocardium, resulting in amyloid transthyretin-associated cardiomyopathy (ATTR-CM). Over 150 different pathologic point mutations within the transthyretin gene have been identified, each carrying variable clinical phenotypes and penetrance. In the USA, the most common cause of hereditary ATTR is the Val122Ile point mutation, with a prevalence of 3.4-4.0% in North Americans of African and Caribbean descent. Among Caucasians with hereditary ATTR-CM, the V30M mutation is the most commonly identified variant. Overall, the incidence of ATTR disease in the USA has been increasing, likely due to an increase in practitioner awareness, utilization of new non-invasive imaging technologies for ATTR diagnosis, and the growth of multidisciplinary amyloid programs across the country. Yet significant numbers of patients with evidence of left ventricular thickening on cardiac imaging, senile aortic stenosis, and/or symptoms of heart failure with preserved ejection fraction likely have undiagnosed CA, especially within the African American population. With the emergence of new disease-modifying therapies for ATTR, recognition and the prompt diagnosis of CA is important for patients and their potentially affected progeny. Herein, we review the genetics of heritable CA as well as the importance of genetic counseling and testing for patients and their families.

Accuracy of risk models used for public reporting of heart transplant center performance

BACKGROUND

Heart transplant programs and regulatory entities require highly accurate performance metrics to support internal quality improvement activities and national oversight of transplant programs, respectively. We assessed the accuracy of publicly reported performance measures.

METHODS

We used the United Network for Organ Sharing registry to study patients who underwent heart transplantation between January 1, 2016 and June 30, 2018. We used tests of calibration to compare the observed rate of 1-year graft failure to the expected risk of 1-year graft failure, which was calculated for each recipient using the July 2019 method published by the Scientific Registry of Transplant Recipients (SRTR). The primary study outcome was the joint test of calibration, which accounts for both the total number of events predicted (calibration-in-the-large) and dispersion of risk predictions (calibration slope).

RESULTS

6,528 heart transplants were analyzed. The primary test of calibration failed (p <0.0001), indicating poor accuracy of the SRTR model. The calibration-in-the-large statistic (0.63, 95% confidence interval [CI] 0.58-0.68, p < 0.0001) demonstrated overestimation of event rates while the calibration slope statistic (0.56, 95% CI 0.49-0.62, p <0.0001) indicated over-dispersion of event rates. Pre-specified subgroup analyses demonstrated poor calibration for all subgroups (each p <0.01). After recalibration, program-level observed/expected ratios increased by a median of 0.14 (p <0.0001).

CONCLUSIONS

Risk models employed for publicly-reported graft survival at U.S. heart transplant centers lack accuracy in general and in all subgroups tested. The use of disease-specific models may improve the accuracy of program performance metrics.

Impact of thoracotomy approach on right ventricular failure and length of stay in left ventricular assist device implants: an intermacs registry analysis

INTRODUCTION

Traditionally, implantation of Left Ventricular Assist Devices (LVADs) is performed via median sternotomy. Recently, less invasive thoracotomy approaches are growing in popularity as they involve less surgical trauma, potentially less bleeding, and may preserve right ventricular function. We hypothesized implantation of LVADs via thoracotomy has less perioperative right ventricular failure (RVF) and shorter postoperative length of stay (LOS).

METHODS

Continuous flow LVAD implants from Intermacs between February 6, 2014 - December 31, 2018 were identified. Patients implanted via thoracotomy were propensity matched in a 1:1 ratio with patients implanted via sternotomy. Outcomes were compared between sternotomy and thoracotomy approach and by device type (axial, centrifugal-flow with hybrid levitation (CF-HL), centrifugal-flow with full magnetic levitation devices (CF-FML)). The primary outcome was time to first moderate or severe RVF. Secondary outcomes included survival and LOS.

RESULTS

Overall 978 thoracotomy patients were matched with 978 sternotomy patients. Over the study period, 242 thoracotomy patients and 219 sternotomy patients developed RVF with no significant difference in time to first moderate to severe RVF by surgical approach overall (p = 0.27) or within CF-HL (p = 0.36) or CF-FML devices (p = 0.25). Survival did not differ by implant technique (150 deaths in thoracotomy group, 154 deaths in sternotomy group; p = 0.58). However, sternotomy approach was associated with a significantly shorter LOS (17 Vs 18 days, p = 0.009).

CONCLUSION

As compared to sternotomy, implantation of continuous flow LVADs via thoracotomy approach does not reduce moderate to severe RVF or improve survival but does reduce post-operative LOS. Device type did not influence outcomes and most centers did a small volume of thoracotomy implants.

Concordance of Treatment Effect: An Analysis of The Society of Thoracic Surgeons Intermacs Database

BACKGROUND

The Society of Thoracic Surgeons (STS) Intermacs Registry represents a real-world data source of durable, left ventricular assist devices that can address knowledge gaps not informed through randomized clinical trials. We sought to compare survival with contemporary left ventricular assist device technologies using multiple analytic approaches to assess concordance of treatment effects and to validate prior STS Intermacs observations.

METHODS

Patients (aged > 19 years) enrolled into STS Intermacs between August 2017 - June 2019 were stratified by device type (centrifugal device with hybrid levitation [CF-HL] or full magnetic levitation [CF-FML]). The primary outcome was 1-year survival assessed by three statistical methodologies (multivariable regression, propensity score matching, and instrumental variable analysis).

RESULTS

Of 4,448 patients, 2,012 (45.2%) received CF-HL and 2,436 (54.8%) received CF-FML. One-year survival for CF-FML was 88% vs. 79% for CF-HL (overall p < .001), with a hazard ratio for mortality of 3.18 for CF-HL (p<0.0001) after risk adjustment. With propensity score matching (n=1400 each cohort), 1-year survival was 87% for CF-FML vs. 80% for CF-HL, with a hazard ratio of 3.20 for mortality with CF-HL (p<0.0001) after risk adjustment. With an instrumental variable analysis, the probability of receiving CF-HL was associated with a hazard ratio of 3.11 (p<0.0001).

CONCLUSIONS

Statistical methodology using propensity score matching and instrumental variable analysis increased the robustness of observations derived from real-world data and demonstrates the feasibility of performing comparative effectiveness research using STS Intermacs. These analyses provide additional evidence supporting a survival benefit of CF-FML versus CF-HL.

Creation and Validation of a Novel Sex-Specific Mortality Risk Score in LVAD Recipients

Background

Prior studies have shown that women have worse 3‐month survival after receiving a left ventricular assist device compared with men. Currently used prognostic scores, including the Heartmate II Risk Score, do not account for the increased residual risk in women. We used the IMACS (International Society for Heart and Lung Transplantation Mechanically Assisted Circulatory Support) registry to create and validate a sex‐specific risk score for early mortality in left ventricular assist device recipients.

Methods and Results

Adult patients with a continuous‐flow LVAD from the IMACS registry were randomly divided into a derivation cohort (DC; n=9113; 21% female) and a validation cohort (VC; n=6074; 21% female). The IMACS Risk Score was developed in the DC to predict 3‐month mortality, from preoperative candidate predictors selected using the Akaike information criterion, or significant sex × variable interaction. In the DC, age, cardiogenic shock at implantation, body mass index, blood urea nitrogen, bilirubin, hemoglobin, albumin, platelet count, left ventricular end‐diastolic diameter, tricuspid regurgitation, dialysis, and major infection before implantation were retained as significant predictors of 3‐month mortality. There was significant ischemic heart failure × sex and platelet count × sex interaction. For each quartile increase in IMACS risk score, men (odds ratio [OR], 1.86; 95% CI, 1.74–2.00; P<0.0001), and women (OR, 1.93; 95% CI, 1.47–2.59; P<0.0001) had higher odds of 3‐month mortality. The IMACS risk score represented a significant improvement over Heartmate II Risk Score (IMACS risk score area under the receiver operating characteristic curve: men: DC, 0.71; 95% CI, 0.69–0.73; VC, 0.69; 95% CI, 0.66–0.72; women: DC, 0.73; 95% CI, 0.70–0.77; VC, 0.71 [95% CI, 0.66–0.76; P<0.01 for improvement in receiver operating characteristic) and provided excellent risk calibration in both sexes. Removal of sex‐specific interaction terms resulted in significant loss of model fit.

Conclusions

A sex‐specific risk score provides excellent risk prediction in LVAD recipients.

Factors influencing palliative care referral for hospitalised patients with heart failure: an exploratory, randomised, multi-institutional survey of hospitalists and cardiologists

OBJECTIVE

To identify factors influencing cardiologists' and hospitalists' decisions regarding palliative care referral among hospitalised patients with advanced heart failure.

DESIGN

An exploratory, randomised vignette-based survey.

SETTING

Cardiology and hospitalist divisions at three Michigan State institutions and the Society of Hospital Medicine's Michigan Chapter.

PARTICIPANTS

145 hospitalists and 64 cardiologists.

OUTCOME MEASURES

Primary outcomes included participants' reports of their likelihood of referring a standardised patient with an acute heart failure exacerbation with multiple prior hospital admissions and acute renal failure to palliative care (scale of 0%-100%) after the initial stem and after being cued with three randomised vignette modifiers, including the presence versus the absence of continuity with an outpatient cardiologist; the presence versus the absence of documented advance care planning; and the patient voicing that he is accepting of his severe illness versus wanting everything done. Adjusted generalised linear models and predictive margins were used to evaluate the impact of each randomised modifier on referral decisions. An interaction term evaluated the effect of provider specialty on outcomes. Secondary outcomes included participants' reports of their general practices around palliative care delivery to hospitalised patients with heart failure.

RESULTS

Response rate was 31.3%. Predictive margins from generalised linear models demonstrated a statistically significantly higher likelihood of referral to inpatient palliative care if the patient lacked an outpatient cardiologist (mean difference: 6.3% (95% CI 1.8% to 10.8%)); had prior advance care planning documentation (mean difference: 9.7% (95% CI 4.4% to 15.0%)); and was accepting of illness severity (mean difference: 29.6% (95% CI 24.8% to 34.4%)). No interaction effect was noted based on provider specialty. Most hospitalists and cardiologists were unaware of palliative care guidelines for patients with heart failure (74.3% vs 70.3%, p=0.71).

CONCLUSIONS

A number of patient and provider factors influence palliative care referral decisions in hospitalised patients with advanced heart failure.