Large animal models to study effectiveness of therapy devices in the treatment of heart failure with preserved ejection fraction (HFpEF)

Our understanding of the complex pathophysiology of Heart failure with preserved ejection fraction (HFpEF) is limited by the lack of a robust in vivo model. Existing in-vivo models attempt to reproduce the four main phenotypes of HFpEF; ageing, obesity, diabetes mellitus and hypertension. To date, there is no in vivo model that represents all the haemodynamic characteristics of HFpEF, and only a few have proven to be reliable for the preclinical evaluation of potentially new therapeutic targets. HFpEF accounts for 50% of all the heart failure cases and its incidence is on the rise, posing a huge economic burden on the health system. Patients with HFpEF have limited therapeutic options available. The inadequate effectiveness of current pharmaceutical therapeutics for HFpEF has prompted the development of device-based treatments that target the hemodynamic changes to reduce the symptoms of HFpEF. However, despite the potential of device-based solutions to treat HFpEF, most of these therapies are still in the developmental stage and a relevant HFpEF in vivo model will surely expedite their development process. This review article outlines the major limitations of the current large in-vivo models in use while discussing how these designs have helped in the development of therapy devices for the treatment of HFpEF.

Alterations in Coronary Blood Flow and the Risk of Left Ventricular Distension in Venoarterial Extracorporeal Membrane Oxygenation

Previous theoretical studies have suggested that veno-arterial extracorporeal membrane oxygenation (VA-ECMO) ought to consistently result in markedly increased left ventricular (LV) intracavitary pressures and volumes because of increased LV afterload. However, this phenomenon of LV distension does not universally occur and occurs only in a minority of cases. We sought to explain this discrepancy by considering the potential implications of VA-ECMO support on coronary blood flow and consequently improved LV contractility (the "Gregg" effect), in addition to the effects of VA-ECMO support upon LV loading conditions, in a lumped parameter-based theoretical circulatory model. We found that LV systolic dysfunction resulted in reduced coronary blood flow; VA-ECMO support augmented coronary blood flow proportionally to the circuit flow rate. On VA-ECMO support, a weak or absent Gregg effect resulted in increased LV end-diastolic pressures and volumes and increased end-systolic volume with decreased LV ejection fraction (LVEF), consistent with LV distension. In contrast, a more robust Gregg effect resulted in unaffected and/or even reduced LV end-diastolic pressure and volume, end-systolic volume, and unaffected or even increased LVEF. Left ventricular contractility augmentation proportional to coronary blood flow increased by VA-ECMO support may be an important contributory mechanism underlying why LV distension is observed only in a minority of cases.

Long-Term Outcomes of Allogeneic Hematopoietic Cell Transplantation in Patients with Newly Diagnosed Multiple Myeloma

Despite remarkable progress in survival with the availability of novel agents, an overwhelming majority of patients with multiple myeloma (MM) have disease that relapses. Allogeneic (allo-) hematopoietic cell transplantation (HCT) is a potentially curative option for a subgroup of patients with high-risk MM. This study assessed the long-term outcome of MM patients who underwent allo-HCT while in first remission as consolidation treatment. Thirty-three patients with newly diagnosed MM who underwent allo-HCT as part of consolidation therapy between 1994 and 2016 were reviewed retrospectively. Of these patients, 70% underwent autologous HCT before allo-HCT. All patients were chemosensitive and achieved at least partial response before proceeding to allo-HCT. Most received nonmyeloablative/reduced-intensity conditioning (88%) and a matched sibling donor graft (85%). Acute graft-versus-host disease (GVHD) and chronic GVHD occurred in 30% and 61% of patients, respectively. The median duration of follow-up was 64.1 months (range, 1.4 to 199.2 months) for all patients and 164.4 months (range, 56.0 to 199.2 months) for survivors. The median progression-free survival (PFS) was 36 months (95% confidence interval (CI), 8.6 to 73.0 months). The median time from treatment to progression was 73.0 months (95% CI, 30.6 months to not reached). The median overall survival (OS) was 131.9 months (95% CI, 38.4 months to not reached). Of all patients, 39% were alive for more than 10 years, with 46% (n = 6) without progression or relapse. The cumulative incidence of relapse was 18% at 1 year, 39% at 5 years, and 46% at 10 years post-allo-HCT. The cumulative incidence of nonrelapse mortality was 3% at 100 days, 18% at 1 year, 21% at 3 years, and 24% at 5 year post-allo-HCT. On multivariable analysis, high-risk cytogenetics were associated with a shorter PFS (hazard ratio [HR], 2.7; 95% CI, 1.01 to 7.21; P = .047) and OS (HR, 4.91; 95% CI, 1.48 to 16.27; P = .009). Achieving complete remission after allo-HCT also was associated with longer PFS (HR, 0.24; 95% CI, 0.09 to 0.64; P = .004) and OS (HR, .23; 95% CI, .07 to .72; P = .012). Allo-HCT may confer a survival advantage in a selected population of MM patients when performed early in the disease course; additional data on identifying the patients who will benefit the most are needed.

Device-Based Solutions to Improve Cardiac Physiology and Hemodynamics in Heart Failure With Preserved Ejection Fraction

Characterized by a rapidly increasing prevalence, elevated mortality and rehospitalization rates, and inadequacy of pharmaceutical therapies, heart failure with preserved ejection fraction (HFpEF) has motivated the widespread development of device-based solutions. HFpEF is a multifactorial disease of various etiologies and phenotypes, distinguished by diminished ventricular compliance, diastolic dysfunction, and symptoms of heart failure despite a normal ejection performance; these symptoms include pulmonary hypertension, limited cardiac reserve, autonomic imbalance, and exercise intolerance. Several types of atrial shunts, left ventricular expanders, stimulation-based therapies, and mechanical circulatory support devices are currently under development aiming to target one or more of these symptoms by addressing the associated mechanical or hemodynamic hallmarks. Although the majority of these solutions have shown promising results in clinical or preclinical studies, no device-based therapy has yet been approved for the treatment of patients with HFpEF. The purpose of this review is to discuss the rationale behind each of these devices and the findings from the initial testing phases, as well as the limitations and challenges associated with their clinical translation.

Multi-institutional Analysis of 200 COVID-19 Patients treated with ECMO:Outcomes and Trends

Background

The role of extracorporeal membrane oxygenation (ECMO) in the management of patients with COVID-19 continues to evolve. The purpose of this analysis is to review our multi-institutional clinical experience involving 200 consecutive patients at 29 hospitals with confirmed COVID-19 supported with ECMO.

Methods

This analysis includes our first 200 COVID-19 patients with complete data who were supported with and separated from ECMO. These patients were cannulated between March 17 and December 1, 2020. Differences by mortality group were assessed using χ² tests for categoric variables and Kruskal-Wallis rank sum tests and Welch’s analysis of variance for continuous variables.

Results

Median ECMO time was 15 days (interquartile range, 9 to 28). All 200 patients have separated from ECMO: 90 patients (45%) survived and 110 patients (55%) died. Survival with venovenous ECMO was 87 of 188 patients (46.3%), whereas survival with venoarterial ECMO was 3 of 12 patients (25%). Of 90 survivors, 77 have been discharged from the hospital and 13 remain hospitalized at the ECMO-providing hospital. Survivors had lower median age (47 versus 56 years, P < .001) and shorter median time from diagnosis to ECMO cannulation (8 versus 12 days, P = .003). For the 90 survivors, adjunctive therapies on ECMO included intravenous steroids (64), remdesivir (49), convalescent plasma (43), anti-interleukin-6 receptor blockers (39), prostaglandin (33), and hydroxychloroquine (22).

Conclusions

Extracorporeal membrane oxygenation facilitates survival of select critically ill patients with COVID-19. Survivors tend to be younger and have a shorter duration from diagnosis to cannulation. Substantial variation exists in drug treatment of COVID-19, but ECMO offers a reasonable rescue strategy.

Multi-institutional Analysis of 100 Consecutive Patients with COVID-19 and Severe Pulmonary Compromise Treated with Extracorporeal Membrane Oxygenation: Outcomes and Trends Over Time

The role of extracorporeal membrane oxygenation (ECMO) in the management of severely ill patients with coronavirus disease 2019 (COVID-19) continues to evolve. The purpose of this study is to review a multi-institutional clinical experience in 100 consecutive patients, at 20 hospitals, with confirmed COVID-19 supported with ECMO. This analysis includes our first 100 patients with complete data who had confirmed COVID-19 and were supported with ECMO. The first patient in the cohort was placed on ECMO on March 17, 2020. Differences by the mortality group were assessed using χ2 tests for categorical variables and Kruskal-Wallis rank-sum tests and Welch's analysis of variance for continuous variables. The median time on ECMO was 12.0 days (IQR = 8-22 days). All 100 patients have since been separated from ECMO: 50 patients survived and 50 patients died. The rate of survival with veno-venous ECMO was 49 of 96 patients (51%), whereas that with veno-arterial ECMO was 1 of 4 patients (25%). Of 50 survivors, 49 have been discharged from the hospital and 1 remains hospitalized at the ECMO-providing hospital. Survivors were generally younger, with a lower median age (47 versus 56.5 years, p = 0.014). In the 50 surviving patients, adjunctive therapies while on ECMO included intravenous steroids (26), anti-interleukin-6 receptor blockers (26), convalescent plasma (22), remdesivir (21), hydroxychloroquine (20), and prostaglandin (15). Extracorporeal membrane oxygenation may facilitate salvage and survival of selected critically ill patients with COVID-19. Survivors tend to be younger. Substantial variation exists in the drug treatment of COVID-19, but ECMO offers a reasonable rescue strategy.

Survival on the Heart Transplant Waiting List

Importance

With continuing improvements in medical devices and more than a decade since the 2006 United Network for Organ Sharing (UNOS) allocation policy, it is pertinent to assess survival among patients on the heart transplantation waiting list, especially given the recently approved 2018 UNOS allocation policy.

Objectives

To assess survival outcomes among patients on the heart transplant waiting list during the past 3 decades and to examine the association of ventricular assist devices (VADs) and the 2006 UNOS allocation policy with survival.

Design, Setting, and Participants

A retrospective cross-sectional used the UNOS database to perform an analysis of 95 323 candidates wait-listed for heart transplantation between January 1, 1987, and December 29, 2017. Candidates for all types of combined transplants were excluded (n = 2087). Patients were followed up from the time of listing to death, transplantation, or removal from the list due to clinical improvement. Competing-risk, Kaplan-Meier, and multivariable Cox proportional hazards regression analyses were used.

Main Outcomes and Measures

The analysis involved an unadjusted and adjusted survival analysis in which the primary outcome was death on the waiting list. Because of changing waiting list preferences and policies during the study period, the intrinsic risk of death for wait-listed candidates was assessed by individually analyzing, comparing, and adjusting for several candidate risk factors.

Results

In total, 95 323 candidates (72 915 men [76.5%]; mean [SD] age, 51.9 [12.0] years) were studied. In the setting of changes in listing preferences, 1-year survival on the waiting list increased from 34.1% in 1987-1990 to 67.8% in 2011-2017 (difference in proportions, 0.34%; 95% CI, 0.32%-0.36%; P < .001). The 1-year waiting list survival for candidates with VADs increased from 10.2% in 1996-2000 to 70.0% in 2011-2017 (difference in proportions, 0.60%; 95% CI, 0.58%-0.62%; P < .001). Similarly, in the setting of changing mechanical circulatory support indications, the 1-year waiting list survival for patients without VADs increased from 53.9% in 1996-2000 to 66.5% in 2011-2017 (difference in proportions, 0.13%; 95% CI, 0.12%-0.14%; P < .001). In the decade prior to the 2006 UNOS allocation policy, the 1-year waiting list survival was 51.1%, while in the decade after it was 63.9% (difference in proportions, 0.13%; 95% CI, 0.12%-0.14%; P < .001). In adjusted analysis, each time period after 1987-1990 had a marked decrease in waiting list mortality.

Conclusions and Relevance

This study found temporally associated increases in heart transplant waiting list survival for all patient groups (with or without VADs, UNOS status 1 and status 2 candidates, and candidates with poor functional status).

Trans-ventricular catheter device-based closure of postmyocardial infarction ventricular septal defect following coronary artery bypass grafting: A staged hybrid approach

A 66-year-old woman with a history of hypertension, ischemic stroke, and rheumatoid arthritis presented to the hospital with severe angina pectoris and dyspnea and was diagnosed with myocardial infarction (MI). Coronary angiography revealed multisystem coronary artery occlusive disease. Due to refractory myocardial ischemia/evolving MI, emergency coronary artery bypass grafting (CABG) was undertaken. Intraoperative transesophageal echocardiography additionally revealed an apical muscular ventricular septal defect (VSD). Concomitant VSD repair was deferred due to the absence of surface evidence of transmural MI for left ventriculotomy, in the setting of pre-existing severe left ventricular dysfunction. An initial totally percutaneous attempt to close the VSD postoperatively failed. A hybrid surgical/catheter-based VSD closure was performed on postoperative day 4, with a successful outcome. The patient did well postoperatively and currently is alive in good condition. To the best of our knowledge, this is the first report of a staged (post-CABG) and hybrid surgical/catheter-based technique without the utilization of cardiopulmonary bypass.

Towards the use of localised delivery strategies to counteract cancer therapy-induced cardiotoxicities

Cancer therapies have significantly improved cancer survival; however, these therapies can often result in undesired side effects to off target organs. Cardiac disease ranging from mild hypertension to heart failure can occur as a result of cancer therapies. This can warrant the discontinuation of cancer treatment in patients which can be detrimental, especially when the treatment is effective. There is an urgent need to mitigate cardiac disease that occurs as a result of cancer therapy. Delivery strategies such as the use of nanoparticles, hydrogels, and medical devices can be used to localise the treatment to the tumour and prevent off target side effects. This review summarises the advancements in localised delivery of anti-cancer therapies to tumours. It also examines the localised delivery of cardioprotectants to the heart for patients with systemic disease such as leukaemia where localised tumour delivery might not be an option.

Catching and killing of airborne SARS-CoV-2 to control spread of COVID-19 by a heated air disinfection system

Airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) via air-conditioning systems poses a significant threat for the continued escalation of the current coronavirus disease (COVID-19) pandemic. Considering that SARS-CoV-2 cannot tolerate temperatures above 70 °C, here we designed and fabricated efficient filters based on heated nickel (Ni) foam to catch and kill SARS-CoV-2. Virus test results revealed that 99.8% of the aerosolized SARS-CoV-2 was caught and killed by a single pass through a novel Ni-foam-based filter when heated up to 200 °C. In addition, the same filter was also used to catch and kill 99.9% of Bacillus anthracis, an airborne spore. This study paves the way for preventing transmission of SARS-CoV-2 and other highly infectious airborne agents in closed environments.

Catching and killing of airborne SARS-CoV-2 to control spread of COVID-19 by a heated air disinfection system

Airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) via air-conditioning systems poses a significant threat for the continued escalation of the current coronavirus disease (COVID-19) pandemic. Considering that SARS-CoV-2 cannot tolerate temperatures above 70 °C, here we designed and fabricated efficient filters based on heated nickel (Ni) foam to catch and kill SARS-CoV-2. Virus test results revealed that 99.8% of the aerosolized SARS-CoV-2 was caught and killed by a single pass through a novel Ni-foam-based filter when heated up to 200 °C. In addition, the same filter was also used to catch and kill 99.9% of Bacillus anthracis, an airborne spore. This study paves the way for preventing transmission of SARS-CoV-2 and other highly infectious airborne agents in closed environments.

Association of cardiovascular risk factor profile and financial hardship from medical bills among non-elderly adults in the United States

Background

While optimal cardiovascular risk factor (CRF) profile is associated with lower mortality, morbidity, and healthcare expenditures among individuals with atherosclerotic cardiovascular disease (ASCVD), less is known regarding its impact on financial hardship from medical bills. Therefore, we assessed whether an optimal CRF profile is associated with a lower burden of financial hardship from medical bills and a reduction in cost-related barriers to health.

Methods

We used a nationally representative sample of adults between 18 and 64 years from the National Health Interview Survey between 2013 and 2017. We assessed ASCVD status and the number of risk factors to categorize the study population into 4 mutually exclusive categories: ASCVD (irrespective of CRF profile) and non-ASCVD with poor, average, and optimal CRF profile. Adjusted logistic regression model was used to determine the association of ASCVD/CRF profile with financial hardship from medical bills and cost-related barriers to health (cost-related medication non-adherence (CRN), foregone/delayed care, and high financial distress).

Results

We included 119,388 non-elderly adults, representing 189 million individuals annually across the United States. Non-ASCVD/optimal CRF profile individuals had a lower prevalence of financial hardship and an inability paying medical bills when compared with individuals with ASCVD (24% vs 45% and 6% vs 19%, respectively). Among individuals without ASCVD and an optimal CRF profile, the prevalence of each cost-related barrier to health was <50% compared with individuals with ASCVD. Poor/low income and uninsured individuals within non-ASCVD/average CRF profile strata had a lower prevalence of financial hardship and an inability paying medical bills when compared with middle/high income and insured individuals with ASCVD. Non-ASCVD individuals with optimal CRF profile had the lowest odds of all barriers to health.

Conclusion

Optimal CRF profile is associated with a lower prevalence of financial hardship from medical bills and cost-related barriers to health despite lower income and lack of insurance.

Advanced Pulmonary and Cardiac Support of COVID-19 Patients: Emerging Recommendations From ASAIO-A "Living Working Document"

The severe acute respiratory syndrome (SARS)-CoV-2 is an emerging viral pathogen responsible for the global coronavirus disease 2019 (COVID)-19 pandemic resulting in significant human morbidity and mortality. Based on preliminary clinical reports, hypoxic respiratory failure complicated by acute respiratory distress syndrome is the leading cause of death. Further, septic shock, late-onset cardiac dysfunction, and multiorgan system failure are also described as contributors to overall mortality. Although extracorporeal membrane oxygenation and other modalities of mechanical cardiopulmonary support are increasingly being utilized in the treatment of respiratory and circulatory failure refractory to conventional management, their role and efficacy as support modalities in the present pandemic are unclear. We review the rapidly changing epidemiology, pathophysiology, emerging therapy, and clinical outcomes of COVID-19; and based on these data and previous experience with artificial cardiopulmonary support strategies, particularly in the setting of infectious diseases, provide consensus recommendations from ASAIO. Of note, this is a "living document," which will be updated periodically, as additional information and understanding emerges.

Advanced Pulmonary and Cardiac Support of COVID-19 Patients: Emerging Recommendations From ASAIO-a Living Working Document

The severe acute respiratory syndrome-CoV-2 is an emerging viral pathogen responsible for the global coronavirus disease 2019 pandemic resulting in significant human morbidity and mortality. Based on preliminary clinical reports, hypoxic respiratory failure complicated by acute respiratory distress syndrome is the leading cause of death. Further, septic shock, late-onset cardiac dysfunction, and multiorgan system failure are also described as contributors to overall mortality. Although extracorporeal membrane oxygenation and other modalities of mechanical cardiopulmonary support are increasingly being utilized in the treatment of respiratory and circulatory failure refractory to conventional management, their role and efficacy as support modalities in the present pandemic are unclear. We review the rapidly changing epidemiology, pathophysiology, emerging therapy, and clinical outcomes of coronavirus disease 2019; and based on these data and previous experience with artificial cardiopulmonary support strategies, particularly in the setting of infectious diseases, provide consensus recommendations from American Society for Artificial Internal Organs. Of note, this is a living document, which will be updated periodically, as additional information and understanding emerges.

Heterotopic Cardiac Transplantation: Long-term Results and Fate of the Native Heart

BACKGROUND

The long-term results of heterotopic cardiac transplantation have not been well defined. Patient survival rates and the fate of the native heart remain unclear.

METHODS

This study is a retrospective review of all 46 heterotopic cardiac transplantations performed at a single institution, the Texas Heart Institute in Houston, Texas, between 1982 and 2017. Four patients who underwent heterotopic transplantation as an emergency procedure for cardiogenic shock were excluded. Three of the procedures were repeat transplantations in patients who had previously undergone heterotopic transplantation; the 3 repeat transplantations were excluded, but the original procedures were not. Follow-up was 100% complete for mortality and 77% complete (30 of 39 patients) for assessment of preoperative indication for surgery and postoperative cardiac function.

RESULTS

For the 39 patients, the 1-year, 5-year, and 10-year survival rates were 69%, 36%, and 21%, respectively. One patient remains alive 25 years after the transplantation procedure. The most frequent indication for heterotopic transplantation was pulmonary vascular resistance greater than 4 Wood units (n = 11), followed by weight greater than 112.5 kg (n = 7). In most patients, native heart left ventricular ejection fraction stabilized over time to between 10% and 30%. Sinus rhythm was preserved in 87% (26 of 30) of native hearts at long-term follow-up.

CONCLUSIONS

Heterotopic cardiac transplantation is an acceptable procedure that should be considered for obese patients (especially those heavier than 112.5 kg) and patients with elevated pulmonary vascular resistance (especially those with pulmonary vascular resistance >4.0 Wood units). After heterotopic transplantation, native cardiac function appears to stabilize, and there is potential for native heart recovery.

Acute Kidney Injury With Ventricular Assist Device Placement: National Estimates of Trends and Outcomes

RATIONALE & OBJECTIVE

Ventricular assist devices (VADs) are used for end-stage heart failure not amenable to medical therapy. Acute kidney injury (AKI) in this setting is common due to heart failure decompensation, surgical stress, and other factors. Little is known about national trends in AKI diagnosis and AKI requiring dialysis (AKI-D) and associated outcomes with VAD implantation. We investigated national estimates and trends for diagnosed AKI, AKI-D, and associated patient and resource utilization outcomes in hospitalizations in which implantable VADs were placed.

STUDY DESIGN

Cohort study of 20% stratified sample of US hospitalizations.

SETTING & PARTICIPANTS

Patients who underwent implantable VAD placement in 2006 to 2015.

EXPOSURE

No AKI diagnosis, AKI without dialysis, AKI-D.

OUTCOMES

In-hospital mortality, length of stay, estimated hospitalization costs.

ANALYTICAL APPROACH

Multivariate logistic and linear regression using survey design methods to account for stratification, clustering, and weighting.

RESULTS

An estimated 24,140 implantable VADs were placed, increasing from 853 in 2006 to 3,945 in 2015. AKI was diagnosed in 56.1% of hospitalizations and AKI-D occurred in 6.5%. AKI diagnosis increased from 44.0% in 2006 to 2007 to 61.7% in 2014 to 2015; AKI-D declined from 9.3% in 2006 to 2007 to 5.2% in 2014 to 2015. Mortality declined in all AKI categories but this varied by category: those with AKI-D had the smallest decline. Adjusted hospitalization costs were 19.1% higher in those with diagnosed AKI and 39.6% higher in those with AKI-D, compared to no AKI.

LIMITATIONS

Administrative data; timing of AKI with respect to VAD implantation cannot be determined; limited pre-existing chronic kidney disease ascertainment; discharge weights not derived for subpopulation of interest.

CONCLUSIONS

A decreasing proportion of patients undergoing VAD implantation experience AKI-D, but mortality among these patients remains high. AKI diagnosis with VAD implantation is increasing, possibly reflecting changes in AKI surveillance, awareness, and coding.

In Vivo Hemodynamic Evaluation of CH-VAD in a Bovine Model for 14 Days

The CH-VAD is a centrifugal-flow magnetically levitated (maglev) left ventricular assist device (LVAD) used to treat end-stage heart failure. It is implanted in the chest cavity; the inflow cannula is inserted into the apex of the left ventricle, and the outflow graft is anastomosed to the aorta. Among several key VAD system improvements, the CH-VAD has a smaller body size than other LVADs and its maglev system offers a large-gap design that makes it superior in terms of hemocompatibility. In this study, we implanted the CH-VAD in a calf and evaluated the hemodynamic and hemocompatibility characteristics over a 14-day period. The hemodynamic parameters, the pump data, and blood test results were recorded throughout the study. The results showed that the CH-VAD provided hemodynamic stability. Hemocompatibility testing indicated negligible hemolysis throughout the study, and no signs of infection were seen. On necropsy, the results showed only expected focal mild-to-moderate adhesions between the pericardial sac (along the pump) and the adjacent rib cage, and between the pericardial sac and the heart. Gross examination of internal organs was unremarkable. Examination of the CH-VAD after explantation revealed no evidence of thrombus formation internally or around the inflow or outflow cannulas.

Implantable Ventricular Assist Device Use and Outcomes in People With End-Stage Renal Disease

Background

People with end‐stage renal disease (ESRD) are at risk for advanced heart failure, but little is known about use and outcomes of durable mechanical circulatory support in this setting. We examined use and outcomes of implantable ventricular assist devices (VADs) in a national ESRD cohort.

Methods and Results

We performed a retrospective cohort study of Medicare beneficiaries with ESRD who underwent implantable VAD placement from 2006 to 2014. We examined in‐hospital and 1‐year mortality, all‐cause and cause‐specific hospitalizations, and heart/kidney transplantation outcomes. We investigated as predictors demographic factors, time‐period of VAD implantation, primary or post‐cardiotomy implantation, and duration of ESRD before VAD implantation. We identified 96 people with ESRD who underwent implantable VAD placement. At time of VAD implantation, 74 (77.1%) were receiving hemodialysis, 10 (10.4%) were receiving peritoneal dialysis and 12 (12.5%) had renal transplant. Time from incident ESRD to VAD implantation was median 4.0 (interquartile range 1.1, 8.2) years. Mortality during the implantation hospitalization was 40.6%. Within 1 year of implantation 61.5% of people had died. On multivariable analysis, males had half the mortality risk of females. Lower mortality risk was also seen with VAD implantation in a primary setting, and with more recent year of implantation, but these results did not reach statistical significance.

Conclusions

Medicare beneficiaries with ESRD are undergoing durable VAD implantation, often several years after incident ESRD, although in low numbers. Mortality is high among these patients, highlighting the need for investigations to improve treatment selection and management.

Abstract TP392: Evaluation of the CHADS 2 , CHA 2 DS 2 -VASc, and R 2 CHADS 2 Risk Assessment Scores in Continuous Flow LVADs

Background: The development of stroke while on continuous flow left ventricular assist device (CF-LVAD) remains a source of significant morbidity and mortality. The ability to risk stratify these patients can improve postoperative management.

Objective: To describe the overall experience of cerebrovascular accidents in CF-LVAD patients at a large volume tertiary center and compare the utility of CHADS 2 , CHA 2 DS 2 -VASc, and R 2 CHADS 2 scores.

Methods: A retrospective analysis of 522 patients (524 CF-LVADs: HeartMate-II=402; Heartware=122), between 2003 and 2016, was conducted. Post-operative heparin for 2-3 days, warfarin (goal INR 2-3), and 80-325mg aspirin were administered daily. Cerebrovascular vascular accident (CVA) was defined as any focal or global deficit with positive imaging. The CHADS 2 , R 2 CHADS 2 and CHA 2 DS 2 -VASc scores were calculated. Baseline characteristics and risk assessment scores were compared between patients with ischemic CVA (ICVA) and no CVA (nCVA). Kaplan-Meier analysis was conducted.

Results: Mean age was 54.7±13.6 years, 21.8% were female and 44.8% had ischemic cardiomyopathy. Eighty patients (15.3%) had 98 events of ICVA. Median duration between implant and ICVA was 127 [range 1-2226] days. Hemorrhagic conversion occurred in 9 (9.2%) patients. The CHADS 2 (ICVA=2.4±1.0, nCVA=2.3±1.1, p-value=0.53), CHA 2 DS 2 -VASc (ICVA=3.2±1.3, nCVA=2.9±1.3, p-value=0.08) and R 2 CHADS 2 (ICVA=3.5±1.5, nCVA=3.2±1.6, p-value=0.22) were all higher for ICVA cohort. Patients with multiple ICVAs had a mean CHADS 2 score of 2.5±0.74, CHA 2 DS 2 -VASc score of 3.5±1.1, and R 2 CHADS 2 score of 4±1.2. Freedom from stroke was significantly lower in the CHA 2 DS 2 -VASc ≥3 compared to the CHA 2 DS 2 -VASc <3 [Figure: Kaplan-Meier log-rank p-value=0.009].

Conclusion: CHA 2 DS 2 -VASc of ≥3 was associated with ICVA in this cohort of CF-LVAD patients. Specifically tailored risk-scores are needed to better predict those at risk for neurological events in CF-LVADs

Contemporary outcomes of operations for tricuspid valve infective endocarditis

BACKGROUND

Tricuspid valve infective endocarditis (TVIE) is uncommon. Patients are traditionally treated with antibiotics alone, and indications for operation are not clearly established. We report our operative single-center experience.

METHODS

We retrospectively reviewed 56 patients who underwent operations for TVIE between January 2002 and December 2012.

RESULTS

Methicillin-resistant Staphylococcus aureus was present in 41% of patients, septic pulmonary emboli in 63%, moderate/severe tricuspid regurgitation in 66%, and 86% were intravenous drug abusers. Patients underwent early operation if there was concomitant left-sided endocarditis with indications for operation (n = 18), atrial septal defect (n = 6), infected pacemaker lead (n = 4), or prosthetic TVIE (n = 1). The remaining 27 patients were treated with intravenous antibiotics. Five patients completed a 6-week course of intravenous antibiotics before requiring an operation for symptomatic severe tricuspid regurgitation or persistent bacteremia. Twenty-two patients did not complete the antibiotic therapy and underwent operation for symptomatic severe tricuspid regurgitation (n = 15), persistent fevers/bacteremia (n = 3), or patient-specific factors (n = 4). Valve repair was successful in 57% of patients. Overall operative mortality was 7.1%. No operative deaths occurred in patients with isolated native TVIE. Recurrent TVIE was diagnosed in 21% (5 of 24) of the replacement group and in 0% (0 of 32) in the repair group. Use of repair was strongly protective against recurrent TVIE (p < 0.01).

CONCLUSIONS

In contrast to previously published reports of high operative mortality with TVIE, this experience demonstrates improved outcomes with low morbidity and mortality, particularly for native isolated TVIE. Future prospective comparisons between surgically and medically treated patients may help to further define indications and timing for operation for patients with TVIE.

Separation of mediastinal shed blood during aortic valve surgery elicits a reduced inflammatory response

AIMS

The detrimental effects of inflammation following cardiopulmonary bypass (CPB) could negatively affect the postoperative outcome in a specific subset of high-risk patients. We therefore investigated the impact of a CPB circuit (Admiral, Eurosets, Italy) that allows separation of intracavitary and mediastinal blood on the release of biochemical markers and clinical outcome when compared with a conventional circuit.

METHODS

Thirty patients undergoing aortic valve surgery were prospectively enrolled and assigned to Admiral group (Group 1, G1, n = 15) or conventional CPB group (Group 2, G2, n = 15). The Admiral oxygenator allows for a separate collection of mediastinal blood processed through a cell-saver before retransfusion. Clinical data and biochemical parameters were measured preoperatively, during CPB and at different time-points postoperatively.

RESULTS

Preoperative demographics, intraoperative data (as CPB and aortic cross-clamping time) and perioperative complications did not differ between groups. Inflammatory response was significantly decreased in G1, as assessed by means of D-dimer (G1 = 1332.3  ±  953.9 vs. G2 = 2791.9  ±  1740.7  ng/ml, P = 0.02), C-reactive protein (G1 = 169.1  ±  164.8 vs. G2 = 57.1  ±  39.3  mg/l, P = 0.04), interleukin-6 (G1 = 11.8  ± 12.5 vs. G2 = 26.5  ±  24.9  pg/ml, P = 0.02) and tumour necrosis factor-alpha (G1 = 29  ±  28.7 vs. G2 = 45.5  ±  23.6 pg/ml, P = 0.03).

CONCLUSION

Although no considerable difference was detected in terms of perioperative outcomes, the Admiral oxygenator did result in a significant reduction of inflammatory markers during the early postoperative course.

Mechanical mitral valve thrombosis in an elderly patient

Prosthetic valve thrombosis is a rare but dreaded complication of mechanical heart valves. In this clinical picture, we present an elderly female who developed mechanical mitral valve thrombosis several years after mitral valve replacement. We have provided fluoroscopy as well as intraoperative images of mitral valve thrombosis and have briefly discussed the diagnosis, and management of this complication.

Patents and Heart Valve Surgery - III: Percutaneous Heart Valves

Advancements in technology for the treatment of valvularcardiac diseases seek to provide solutions for high risk patients in the form of percutaneous valve insertion for patients with complicated valvular disease not amenable to more traditional options. Within the last decade, cardiac valves designed for percutaneous insertion have emerged rapidly as a treatment option for valvular disease. This procedure serves as an alternative to open heart surgery, which is more invasive and requires longer ICU stay. Thus, the percutaneous valve insertion procedure has been used on older, frailer patients who are poor candidates for open heart surgery. Designs for percutaneous valve insertion systems have been in development for decades, but have only recently been approved by the FDA for use. Important considerations include stent design, valve design, balloon catheter design, and deployment method.

Deep RNA sequencing reveals dynamic regulation of myocardial noncoding RNAs in failing human heart and remodeling with mechanical circulatory support

BACKGROUND

Microarrays have been used extensively to profile transcriptome remodeling in failing human heart, although the genomic coverage provided is limited and fails to provide a detailed picture of the myocardial transcriptome landscape. Here, we describe sequencing-based transcriptome profiling, providing comprehensive analysis of myocardial mRNA, microRNA (miRNA), and long noncoding RNA (lncRNA) expression in failing human heart before and after mechanical support with a left ventricular (LV) assist device (LVAD).

METHODS AND RESULTS

Deep sequencing of RNA isolated from paired nonischemic (NICM; n=8) and ischemic (ICM; n=8) human failing LV samples collected before and after LVAD and from nonfailing human LV (n=8) was conducted. These analyses revealed high abundance of mRNA (37%) and lncRNA (71%) of mitochondrial origin. miRNASeq revealed 160 and 147 differentially expressed miRNAs in ICM and NICM, respectively, compared with nonfailing LV. Among these, only 2 (ICM) and 5 (NICM) miRNAs are normalized with LVAD. RNASeq detected 18 480, including 113 novel, lncRNAs in human LV. Among the 679 (ICM) and 570 (NICM) lncRNAs differentially expressed with heart failure, ≈10% are improved or normalized with LVAD. In addition, the expression signature of lncRNAs, but not miRNAs or mRNAs, distinguishes ICM from NICM. Further analysis suggests that cis-gene regulation represents a major mechanism of action of human cardiac lncRNAs.

CONCLUSIONS

The myocardial transcriptome is dynamically regulated in advanced heart failure and after LVAD support. The expression profiles of lncRNAs, but not mRNAs or miRNAs, can discriminate failing hearts of different pathologies and are markedly altered in response to LVAD support. These results suggest an important role for lncRNAs in the pathogenesis of heart failure and in reverse remodeling observed with mechanical support.

Management for breast implants in patients undergoing mitral valve surgery through a right minithoracotomy

We present the surgical technique and rationale for the management of breast implants in two patients who underwent mitral valve repair through a right minithoracotomy.

Patents and heart valve surgery - II: tissue valves

Valvular heart disease affects millions of Americans yearly and currently requires surgical intervention to repair or replace the defective valves. Through a close-knit collaboration between physicians, scientists and biomedical engineers, a vast degree of research and development has been aimed towards the optimization of prosthetic heart valves. Although various methods have made fantastic strides in producing durable prostheses, the therapeutic efficacy of prosthetic valves is inherently limited by a dependency upon lifelong anticoagulant regimens for recipients - a difficult challenge for many in clinical setting. Thus, biological tissue valves have been developed to circumvent vascular and immunemediated complications by incorporating biological materials to mimic native valves while still maintaining a necessary level of structural integrity. Over the past decade, a multitude of patents pertaining to the refinement of designs as well as the advancement in methodologies and technologies associated with biological tissue valves have been issued. This review seeks to chronicle and characterize such patents in an effort to track the past, present, and future progress as well as project the trajectory of tissue valves in the years to come.