Effectiveness of combined plasma cell therapy and costimulation blockade based desensitization regimen in heart transplant candidates.

BACKGROUND: Desensitization is one of the strategies to reduce antibodies and facilitate heart transplantation in highly sensitized patients. We describe our center's desensitization experience with combination of plasma cell (PC) depletion therapy (with proteasome inhibitor or daratumumab) and costimulation blockade (with belatacept). METHODS: We reviewed five highly sensitized patients who underwent desensitization therapy with plasma cell depletion and costimulation blockade. We evaluated the response to therapy by measuring the changes in cPRA, average MFI, and number of positive beads > 5000MFI. RESULTS: Five patients, mean age of 56 (37-66) years with average cPRA of 98% at 5000 MFI underwent desensitization therapy. After desensitization, mean cPRA decreased from 98% to 70% (p = .09), average number of beads > 5000 MFI decreased from 59 to 37 (p = .15), and average MFI of beads > 5000 MFI decreased from 16713 to 13074 (p = .26). CONCLUSION: Combined PC depletion and CoB could be a reasonable strategy for sustained reduction in antibodies in highly sensitized patients being listed for heart transplantation.

Computational investigation of outflow graft variation impact on hemocompatibility profile in LVADs.

BACKGROUND: Hemocompatibility-related adverse events (HRAE) occur commonly in patients with left ventricular assist devices (LVADs) and add to morbidity and mortality. It is unclear whether the outflow graft orientation can impact flow conditions leading to HRAE. This study presents a simulation-based approach using exact patient anatomy from medical images to investigate the influence of outflow cannula orientation in modulating flow conditions leading to HRAEs. METHODS: A 3D model of a proximal aorta and outflow graft was reconstructed from a computed tomography (CT) scan of an LVAD patient and virtually modified to model multiple cannula orientations (n = 10) by varying polar (cranio-caudal) (n = 5) and off-set (anterior-posterior) (n = 2) angles. Time-dependent computational flow simulations were then performed for each anatomical orientation. Qualitative and quantitative hemodynamics metrics of thrombogenicity including time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), endothelial cell platelet activation potential (ECAP), particle residence time (PRT), and platelet activation potential (PLAP) were analyzed. RESULTS: Within the simulations performed, endothelial cell activation potential (ECAP) and particle residence time (PRT) were found to be lowest with a polar angle of 85°, regardless of offset angle. However, polar angles that produced parameters at levels least associated with thrombosis varied when the offset angle was changed from 0° to 12°. For offset angles of 0° and 12° respectively, flow shear was lowest at 65° and 75°, time averaged wall shear stress (TAWSS) was highest at 85° and 35°, and platelet activation potential (PLAP) was lowest at 65° and 45°. CONCLUSION: This study suggests that computational fluid dynamic modeling based on patient-specific anatomy can be a powerful analytical tool when identifying optimal positioning of an LVAD. Contrary to previous work, our findings suggest that there may be an "ideal" outflow cannula for each individual patient based on a CFD-based hemocompatibility profile.

Repeat left ventricular-assisted device exchange and upgrade from second- to third-generation devices in a high-volume single center.

BACKGROUND: Pump exchange is an established strategy to treat LVAD-related complications such as thrombosis, infection, and driveline failure. Pump upgrades with an exchange to newer generation devices are being performed to the advantage of the patient on long-term support. The safety and efficacy of a repeat LVAD exchange with a concomitant upgrade to a third-generation pump have not been reported. METHODS: We performed a retrospective analysis of all consecutive patients who underwent a repeat LVAD device exchange and upgrade to HeartMate III (HMIII) at Houston Methodist Hospital between December 2018 and December 2020. RESULTS: Five patients underwent exchange and upgrade to HMIII within the specified timeframe. Four patients had already had two prior exchanges (all HMII to HMII), and one patient had one prior exchange (HVAD to HVAD). In all cases, implantation was performed as destination therapy. The surgical exchange was performed via redo median sternotomy on full cardiopulmonary bypass. No unplanned redo surgery of the device component was required. In-hospital mortality was 20% in this very high-risk population. At 1-, 3-, and 6-month follow-up, all discharged patients were on HMIII support, with no major LVAD-related adverse events reported. CONCLUSION: We report the feasibility and safety of a repeat pump exchange with an upgrade to HMIII in a high-volume center. The decision for medical therapy versus surgical exchange has to be tailored to individual cases based on risk factors and clinical stability but in expert hands, even a re-redo surgical approach grants options for good medium-term outcomes.

The utility of beta-hydroxybutyrate in detecting myocardial glucose uptake suppression in patients undergoing inflammatory [18F]-FDG PET studies.

PURPOSE: We evaluated whether serum beta-hydroxybutyrate (BHB) can identify adequate suppression of the left ventricle (LV) among patients undergoing [18F]-fluorodeoxyglucose positron emission tomography ([18F]-FDG PET) for cardiac inflammatory/infectious studies. METHODS: Consecutive patients who underwent [18F]-FDG PET imaging were included. Serum BHB levels were measured in all patients on the day of imaging prior to injecting [18F]-FDG. Myocardial [18F]-FDG suppression was defined if [18F]-FDG uptake in the walls of myocardium, measured using standardized uptake values (SUV), was lower than the blood pool. The optimal threshold of BHB to identify myocardial suppression was based on receiver operating characteristics (ROC) in a random 30% sample of the study population (derivation cohort) and tested in the remaining 70% of sample (validation cohort). RESULTS: A total of 256 images from 220 patients were included. Patients with sufficient LV suppression had significantly higher BHB levels compared to those with non-suppressed myocardium (median (IQR) BHB 0.6 (0.3-0.8) vs. 0.2 (0.2-0.3) mmol/l, p < 0.001, respectively). BHB level ≥ 0.335 mmol/l had a sensitivity of 84.90% and a specificity of 92.60% to identify adequate LV suppression in the validation cohort. All patients (100%) with BHB ≥ 0.41 mmol/l had adequate myocardial suppression compared to 29.63% of patients with BHB ≤ 0.20 mmol/l. CONCLUSION: Serum BHB level can be used at the point of care to identify sufficient LV suppression in patients undergoing [18F]-FDG PET cardiac inflammatory/infectious studies. Central illustration (image to the right) shows representative cases of patient images and BHB and, in the image to the left, shows the sensitivity and specificity to identify left myocardial suppression using BHB in validation group.

Diagnosis of cardiac sarcoidosis: a primer for non-imagers.

Sarcoidosis is a multisystem granulomatous disorder that can potentially involve any organ. Cardiac involvement in sarcoidosis has been reported in up to 25% of patients based on autopsy and imaging studies. The gold standard for diagnosing cardiac sarcoidosis is endomyocardial biopsy demonstrating non-caseating granulomas; however, this technique lacks sensitivity due to the patchy nature of myocardial involvement. This, along with the non-specific clinical presentation, renders the diagnosis of cardiac sarcoidosis extremely challenging. Difficulties in obtaining histopathologic diagnosis and the advances in imaging modalities have led to a paradigm shift toward non-invasive imaging in the diagnosis of cardiac sarcoidosis. Advances in cardiac imaging modalities have also allowed unprecedented insights into the prevalence and natural history of cardiac sarcoidosis. This review discusses the role of non-invasive imaging for diagnosis, risk stratification, and monitoring the response to therapies in cardiac sarcoidosis. Echocardiography remains the first-line modality due to widespread availability and affordability. Cardiac magnetic resonance imaging (CMR) can be used to study cardiac structure, function, and most importantly tissue characterization to detect inflammation and fibrosis. Fluoro-deoxy glucose positron emission tomography (FDG PET) is the gold standard for non-invasive detection of cardiac inflammation, and it offers the unique ability to assess response to therapeutic interventions. Hybrid imaging is a promising technique that allows us to combine the unique strengths of CMR and FDG PET. Understanding the advantages and disadvantages of each of these imaging modalities is crucial in order to tailor the diagnostic algorithm and utilize the most appropriate modality for each patient.

Intravenous immunoglobulin in heart transplant recipients with mild to moderate hypogammaglobulinemia and infection.

BACKGROUND: Hypogammaglobulinemia (HGG) is a complication of solid organ transplantation leading to increased risk of infections. Intravenous immunoglobulin G (IVIG) replacement in patients with HGG may be able to reduce risk and morbidity associated with infection; however, there is scarce data about IVIG in mild to moderate HGG (IgG 400-700 mg/dl) and heart transplant recipients. METHODS: A single center, retrospective study was performed in heart transplant recipients with mild (IgG 500-700 mg/dl) to moderate (IgG 400-499 mg/dl) HGG in the presence of an infection. RESULTS: Forty-two patients were included in this study; 19 patients (45.2%) received IVIG and 23 (54.8%) patients did not. Patients in the IVIG group received on average one dose of IVIG at 0.5 g/kg. No differences in incidence of new infection at 3 months (26.3% vs. 17.4%; P = .71) and 6 months (42.1% vs. 34.8%; P = .63) were observed between the IVIG and non-IVIG groups. Infections based on mild or moderate HGG also had no differences at 3 and 6 months. CONCLUSION: Our findings suggest that a single infusion of IVIG in mild to moderate HGG may have little to no benefit in reducing incidence of new infections. Larger prospective studies are needed to confirm these findings.

Cardiovascular magnetic resonance imaging in suspected cardiac tumour: a multicentre outcomes study.

AIMS: Cardiovascular magnetic resonance (CMR) imaging is a key diagnostic tool for the evaluation of patients with suspected cardiac tumours. Patient management is guided by the CMR diagnosis, including no further testing if a mass is excluded or if only a pseudomass is found. However, there are no outcomes studies validating this approach. METHODS AND RESULTS: In this multicentre study of patients undergoing clinical CMR for suspected cardiac tumour, CMR diagnoses were assigned as no mass, pseudomass, thrombus, benign tumour, or malignant tumour. A final diagnosis was determined after follow-up using all available data. The primary endpoint was all-cause mortality. Among 903 patients, the CMR diagnosis was no mass in 25%, pseudomass in 16%, thrombus in 16%, benign tumour in 17%, and malignant tumour in 23%. Over a median of 4.9 years, 376 patients died. Compared with the final diagnosis, the CMR diagnosis was accurate in 98.4% of patients. Patients with CMR diagnoses of pseudomass and benign tumour had similar mortality to those with no mass, whereas those with malignant tumour [hazard ratio (HR) 3.31 (2.40-4.57)] and thrombus [HR 1.46 (1.00-2.11)] had greater mortality. The CMR diagnosis provided incremental prognostic value over clinical factors including left ventricular ejection fraction, coronary artery disease, and history of extracardiac malignancy (P < 0.001). CONCLUSION: In patients with suspected cardiac tumour, CMR has high diagnostic accuracy. Patients with CMR diagnoses of no mass, pseudomass, and benign tumour have similar long-term mortality. The CMR diagnosis is a powerful independent predictor of mortality incremental to clinical risk factors.

The prognostic role of cardiac positron emission tomography imaging in patients with sarcoidosis: A systematic review.

PURPOSE: Sarcoidosis is a multi-systemic inflammatory disease of unknown etiology. Cardiac sarcoidosis (CS) has been reported in as much as 25% of patients with systemic involvement. 18Fluorodeoxyglucose (FDG) positron emission tomography (PET) has a high diagnostic sensitivity/specificity in the diagnosis of CS. The aim of this review is to summarize evidence on the prognostic role of FDG PET. METHODS: Studies were identified by searching MEDLINE from inception to October 2020. Medical subject headings (MeSH) terms for sarcoidosis; cardiac and FDG PET imaging were used. Studies of any design assessing the prognostic role of FDG PET in patients with either suspected or confirmed cardiac sarcoidosis imaging done at baseline were included. Abnormal PET was defined as abnormal metabolism (presence of focal or focal-on-diffuse uptake of FDG) OR abnormal metabolism and a perfusion defect. Studies reporting any outcome measure were included. Pooled risk ratio for the composite outcome of MACE was done. RESULTS: A total of 6 studies were selected for final inclusion (515 patients, 53.4% women, 19.8% racial minorities.) Studies were institution based, retrospective in design and enrolled consecutive patients. All were observational in nature and published in English. All studies used a qualitative assessment of PET scans (abnormal FDG uptake with or without abnormal perfusion). Two studies assessed quantitative metrics (summed stress score in segments with abnormal FDG uptake, standardized uptake value and cardiac metabolic activity.) All studies reported major adverse cardiovascular events (MACE) as a composite outcome. After a mean follow up ranging from 1.4 to 4.1 years, there were a total of 105 MACE. All studies included death (either all-cause death or sudden cardiac death) and ventricular arrhythmia (ventricular tachycardia or ventricular fibrillation) as a component of MACE. Four of the six studies adjusted for several characteristics in their analysis. All four studies used left ventricular ejection fraction (LVEF). However, other adjustment variables were not consistent across studies. Five studies found a positive prognostic association with the primary outcome, two of which assessing right ventricular uptake. CONCLUSION: Although available evidence indicates FDG PET can be used in the risk stratification of patients with CS, our findings show further studies are needed to quantify the effect in this patient group.

Recent advances in heart failure.

PURPOSE OF REVIEW: Acute heart failure continues to be a challenge as there is limited benefit of numerous agents that have been tested. Cardiac resynchronization therapy remains standard of care, yet timing and need for implantable cardiac defibrillator has been brought into question with the recent randomized trials. Several recent advances have been made towards management of heart failure both in drug and device therapy. The purpose of this review is to provide an update on the most important recent studies on heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF). RECENT FINDINGS: Two new drugs have been added to the armamentarium for HFrEF; ivabradine and angiotensin receptor-neprilysin inhibitors (ARNIs). Initial data from a new left ventricular assist device (LVAD) pump, the HeartMate 3 (HM III), have demonstrated no reports of pump thrombosis at 6 months, but stroke and right ventricle failure continue to be a challenge with comparable rates compared with the HeartMate II. Several large studies in HFpEF failed to show improvement in outcomes and management continues to be geared towards lifestyle modification and symptom relief. SUMMARY: Newer therapies and devices have met with great success, yet there are several therapies that provide no benefit and even harm. A careful review of the recent literature remains instrumental to the effective management of patients with heart failure.

Role of multimodality imaging in patients with left ventricular assist device.

PURPOSE OF REVIEW: The article provides an overview of recent advances in imaging patients with a left ventricular assist device (LVAD). RECENT FINDINGS: There is a growing population of patients with LVADs. LVADs improve survival in patients with end-stage heart failure, but are also associated with significant adverse outcomes. Imaging, particularly echocardiography, plays a critical role in patient selection and in predicting and detecting complications. SUMMARY: Recent studies have illustrated links between imaging parameters with adverse outcomes, such as pump thrombosis, right ventricular failure, and continuous aortic regurgitation. Novel parameters and imaging techniques have been developed.

Sex-Based Differences in Patients With Left Ventricular-Assisted Devices and Strokes.

Background: Sex-based differences in clinical outcomes among patients with stroke related to left ventricular assist devices (LVADs) are not well described. Objectives: In this study, the authors examined differences in clinical characteristics and outcomes in men and women who had a stroke during LVAD hospitalization. Methods: The National Inpatient Sample from 2010 and 2019 was used to identify patients with stroke during LVAD hospitalization. Outcomes of interest include inpatient mortality and clinical complications among men vs women. Weighted logistic regression was used to determine the association of sex and outcomes. Adjustments were made for age and the Elixhauser comorbidity index. Results: In total, 35,820 patients underwent LVAD implantation (77% men), and 6.12% (n = 2,192) of patients experienced stroke. Women who had stroke were younger than men who had stroke (mean age in women was 51 years vs men 59 years, P < 0.001). Men with strokes had a higher burden of comorbidities than women. While there were no differences in the odds of ischemic stroke, women had higher odds of hemorrhagic stroke compared to men (OR: 1.49 [95% CI: 1.02-2.18]). Mortality in patients with LVAD who had stroke was significantly higher than in those without stroke. Between 2010 and 2019, stroke rates significantly increased among men, while the trend remained variable among women. Conclusions: In this national cohort, men had a higher comorbidity burden and had worsening stroke trends over the last decade compared to women. Women had fewer LVAD implants and a higher incidence of hemorrhagic stroke. Understanding the factors that contribute to sex-related outcome disparities among LVAD stroke patients is crucial in addressing these diverging trends.

Bloodstream infections in prolonged use of axillary-placed, intra-aortic balloon-pump support: A single-center study.

Infections from prolonged use of axillary intra-aortic balloon pumps (IABPs) have not been well studied. Bloodstream infection (BSI) occurred in 13% of our patients; however, no difference in outcome was noted between those with BSI and those without. Further studies regarding protocol developments that minimize BSI risk are needed.

Sex Disparities in Left Ventricular Assist Device Implantation: Delayed Presentation and Worse Right Heart Failure.

We explored whether women undergo continuous-flow left ventricular assist device (CF-LVAD) implantation in later stages of heart failure (HF) than men, evidenced by worse preoperative right HF (RHF). We also compared two propensity models with and without preoperative RHF to assess its effect on outcomes. INTERMACS was queried from July 2008 to December 2017. Propensity model 1 matched men and women on age ≥50 years, HF etiology, body surface area, INTERMACS class, comorbidities, device strategy, temporary mechanical circulatory support, and device type. Model 2 included these variables plus LV end-diastolic diameter, right atrial pressure/pulmonary capillary wedge pressure, pulmonary artery pulsatility index, and right ventricular ejection fraction. The primary outcome was all-cause mortality. Secondary outcomes comprise RHF, rehospitalization, renal dysfunction, stroke, and device malfunction. In model 1, characteristics were comparable between 3,195 women and 3,195 men, except women more often had preoperative RHF and postoperative right VAD support and had worse 1 year and overall survival. In model 2, after propensity matching for additional risk factors for preoperative RHF, 1,119 women and 1,119 men had comparable post-LVAD implant RVAD use and survival. These findings suggest that women present more often with biventricular failure and after implantation have higher RHF and mortality rates.

Patients' and physicians' beliefs and attitudes towards integrating personalized risk estimates into patient education about left ventricular assist device therapy.

BACKGROUND: Personalized risk (PR) estimates may enhance clinical decision making and risk communication by providing individualized estimates of patient outcomes. We explored stakeholder attitudes toward the utility, acceptability, usefulness and best-practices for integrating PR estimates into patient education and decision making about Left Ventricular Assist Device (LVAD). METHODS AND RESULTS: As part of a 5-year multi-institutional AHRQ project, we conducted 40 interviews with stakeholders (physicians, nurse coordinators, patients, and caregivers), analyzed using Thematic Content Analysis. All stakeholder groups voiced positive views towards integrating PR in decision making. Patients, caregivers and coordinators emphasized that PR can help to better understand a patient's condition and risks, prepare mentally and logistically for likely outcomes, and meaningfully engage in decision making. Physicians felt it can improve their decision making by enhancing insight into outcomes, enhance tailored pre-emptive care, increase confidence in decisions, and reduce bias and subjectivity. All stakeholder groups also raised concerns about accuracy, representativeness and relevance of algorithms; predictive uncertainty; utility in relation to physician's expertise; potential negative reactions among patients; and overreliance. CONCLUSION: Stakeholders are optimistic about integrating PR into clinical decision making, but acceptability depends on prospectively demonstrating accuracy, relevance and evidence that benefits of PR outweigh potential negative impacts on decision making quality.

The role of innovative modeling and imaging techniques in improving outcomes in patients with LVAD.

Heart failure remains a significant cause of mortality in the United States and around the world. While organ transplantation is acknowledged as the gold standard treatment for end stage heart failure, supply is limited, and many patients are treated with left ventricular assist devices (LVADs). LVADs extend and improve patients' lives, but they are not without their own complications, particularly the hemocompatibility related adverse events (HRAE) including stroke, bleeding and pump thrombosis. Mainstream imaging techniques currently in use to assess appropriate device function and troubleshoot complications, such as echocardiography and cardiac computed tomography, provide some insight but do not provide a holistic understanding of pump induced flow alterations that leads to HRAEs. In contrast, there are technologies restricted to the benchtop-such as computational fluid dynamics and mock circulatory loops paired with methods like particle image velocimetry-that can assess flow metrics but have not been optimized for clinical care. In this review, we outline the potential role and current limitations of converging available technologies to produce novel imaging techniques, and the potential utility in evaluating hemodynamic flow to determine whether LVAD patients may be at higher risk of HRAEs. This addition to diagnostic and monitoring capabilities could improve prevention and treatment of LVAD-induced complications in heart failure patients.

Patient-specific, echocardiography compatible flow loop model of aortic valve regurgitation in the setting of a mechanical assist device.

Background: Aortic regurgitation (AR) occurs commonly in patients with continuous-flow left ventricular assist devices (LVAD). No gold standard is available to assess AR severity in this setting. Aim of this study was to create a patient-specific model of AR-LVAD with tailored AR flow assessed by Doppler echocardiography. Methods: An echo-compatible flow loop incorporating a 3D printed left heart of a Heart Mate II (HMII) recipient with known significant AR was created. Forward flow and LVAD flow at different LVAD speed were directly measured and AR regurgitant volume (RegVol) obtained by subtraction. Doppler parameters of AR were simultaneously measured at each LVAD speed. Results: We reproduced hemodynamics in a LVAD recipient with AR. AR in the model replicated accurately the AR in the index patient by comparable Color Doppler assessment. Forward flow increased from 4.09 to 5.61 L/min with LVAD speed increasing from 8,800 to 11,000 RPM while RegVol increased by 0.5 L/min (2.01 to 2.5 L/min). Conclusions: Our circulatory flow loop was able to accurately replicate AR severity and flow hemodynamics in an LVAD recipient. This model can be reliably used to study echo parameters and aid clinical management of patients with LVAD.

Insidious Mass Within a Sinus.

A 75-year-old patient was incidentally found to have an intracardiac mass by echocardiography. Subsequent cardiac magnetic resonance imaging and cardiac positron emission tomography confirmed a large and possibly malignant mass extending from the right atrium into the coronary sinus. The patient underwent an intracardiac echocardiography guided biopsy, which revealed diffuse B-cell lymphoma, and is currently undergoing rituximab, etoposide, vincristine, cyclophosphamide, and doxorubicin (R-EPOCH)-based chemotherapy.

Outflow cannula alignment in continuous flow left ventricular devices is associated with stroke.

We sought to evaluate whether differences in left ventricular assist device (LVAD) canula alignment are associated with stroke. There is a paucity of clinical data on contribution of LVAD canulae alignment to strokes. We conducted a retrospective analysis of patients who underwent LVAD implantation at Houston Methodist hospital from 2011 to 2016 and included those who had undergone cardiac computed tomography (CT) with contrast. LVAD graft alignment using X-ray, echocardiography, and cardiac CT was evaluated. The primary outcome was stroke within 1 year of LVAD implantation. Of the 101 patients that underwent LVAD Implantation and cardiac CT scan during the study period, 78 met inclusion criteria. The primary outcome occurred in 12 (15.4%) patients with a median time to stroke of 77 days (interquartile range: 42-132 days). Of these, 10 patients had an ischemic and two had hemorrhagic strokes. The predominant device type was Heart Mate II (94.8%). Patients with LVAD outflow cannula to aortic angle lesser than 37.5° and those with outflow graft diameter of anastomosis less than 1.5 cm (assessed by cardiac CT) had significantly higher stroke risk (p < 0.001 and p = 0.01 respectively). In HMII patients, a lower LVAD speed at the time of CT scan was associated with stroke. Further studies are needed to identify optimal outflow graft configuration to mitigate stroke risk.

Giant Coronary Sinus Complicated by Spontaneous Thrombosis.

Spontaneous coronary sinus thrombosis (CST) is an extremely rare occurrence. Most cases are iatrogenic and related to right heart instrumentation, due to either central line placement or electrophysiology procedures such as pacemaker insertion that causes direct damage to the endothelial lining. The course can be insidious and may result in a fatal outcome. Diagnosis of CST is challenging, and the syndrome often goes unrecognized. However, in the current era of multimodality imaging, it is possible that this condition will be recognized in more patients. Herein, we present a patient with spontaneous coronary sinus thrombosis that was diagnosed using multimodality imaging and thereafter successfully managed.