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.

Atrial Fibrillation Ablation-induced Pulmonary Venous Occlusion Requiring Pneumonectomy.

A 71-year-old woman with a history of atrial fibrillation underwent a catheter-based ablation procedure. Months later, she presented with dyspnea and a left-sided pleural effusion. Diagnostic evaluation revealed left-sided pulmonary venous occlusion, with essentially absent left lung perfusion. The patient underwent left pneumonectomy, with left atrial appendage occlusion. Although lobectomy for pulmonary venous occlusion of a single vein after pulmonary vein isolation has been described, this appears to be a novel report of occluded pulmonary venous drainage of an entire lung necessitating pneumonectomy.

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.

Multi-institutional Analysis of 505 Patients With Coronavirus Disease-2019 Supported With Extracorporeal Membrane Oxygenation: Predictors of Survival.

BACKGROUND: We reviewed our experience with 505 patients with confirmed coronavirus disease-2019 (COVID-19) supported with extracorporeal membrane oxygenation (ECMO) at 45 hospitals and estimated risk factors for mortality. METHODS: A multi-institutional database was created and used to assess all patients with COVID-19 who were supported with ECMO. A Bayesian mixed-effects logistic regression model was estimated to assess the effect on survival of multiple potential risk factors for mortality, including age at cannulation for ECMO as well as days between diagnosis of COVID-19 and intubation and days between intubation and cannulation for ECMO. RESULTS: Median time on ECMO was 18 days (interquartile range, 10-29 days). All 505 patients separated from ECMO: 194 patients (38.4%) survived and 311 patients (61.6%) died. Survival with venovenous ECMO was 184 of 466 patients (39.5%), and survival with venoarterial ECMO was 8 of 30 patients (26.7%). Survivors had lower median age (44 vs 51 years, P < .001) and shorter median time interval from diagnosis to intubation (7 vs 11 days, P = .001). Adjusting for several confounding factors, we estimated that an ECMO patient intubated on day 14 after the diagnosis of COVID-19 vs day 4 had a relative odds of survival of 0.65 (95% credible interval, 0.44-0.96; posterior probability of negative effect, 98.5%). Age was also negatively associated with survival: relative to a 38-year-old patient, we estimated that a 57-year-old patient had a relative odds of survival of 0.43 (95% credible interval, 0.30-0.61; posterior probability of negative effect, >99.99%). CONCLUSIONS: ECMO facilitates salvage and survival of select critically ill patients with COVID-19. Survivors tend to be younger and have shorter time from diagnosis to intubation. Survival of patients supported with only venovenous ECMO was 39.5%.

Multi-institutional Analysis of 200 COVID-19 Patients Treated With Extracorporeal Membrane Oxygenation: 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.

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 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.

Early Usage of Extracorporeal Membrane Oxygenation in the Absence of Invasive Mechanical Ventilation to Treat COVID-19-related Hypoxemic Respiratory Failure.

A subset of patients with coronavirus disease 2019 (COVID-19) develop profound respiratory failure and are treated via invasive mechanical ventilation (IMV). Of these, a smaller subset has severe gas exchange abnormalities that are refractory to maximal levels of IMV support. Extracorporeal membrane oxygenation (ECMO) has been used successfully in these circumstances. However, using ECMO only after failure of IMV exposes patients to the risks of ventilator-induced lung injury. We report a successful outcome using ECMO in the setting of COVID-19 in the absence of IMV failure in an awake, nonintubated patient. This approach may be beneficial for selected patients with COVID-19.

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.