Impact of mechanical circulatory support on donor heart allocation: past, present, and future.

The United Network for Organ Sharing (UNOS) recently revised its heart allocation policy to address numerous shortcomings of the previous system. Implemented in 2018, the changes sought to reduce waiting list mortality, clearly define urgency status based on objective physiologic variables, decrease exemption requests, and introduce geographic modifications to ensure organ distribution favors the highest urgency candidates. In large part, UNOS policy revisions were driven by the growing use of continuous flow left ventricular assist devices (CF-LVADs) and the relevant device complications that led to an unacceptably high number of status exemptions. The new 6-tiered system assigns a comparatively lower urgency status to patients supported on CF-LVADs and higher urgency to patients supported on short-term mechanical circulatory assist (MCA) such as extracorporeal membrane oxygenation (ECMO) and intraaortic balloon pump (IABP) counterpulsation. LVAD use as bridge to transplant (BTT) therapy increased steadily throughout the preceding decade due to technological improvements and increased physician familiarity, but the recent policy changes introduce incentives for physicians to withhold this life-saving therapy in order to achieve higher urgency status for their patients. This paper will explore the technological evolution of MCA and the pertinent clinical trials that have led to their FDA approval as BTT and destination therapy. A review of the inception and development of the donor allocation system will be provided before examining available post-policy outcome data. Finally, we will highlight successes and shortcomings of the implemented changes before commenting on areas to potentially expand upon the existing policy

Atypical Reactivation of Varicella Zoster Virus Associated with Pancreatitis in a Heart Transplant Patient.

BACKGROUND Acute pancreatitis is rare following solid organ transplantation but is associated with high mortality. It has been most commonly reported following renal transplant but can occur with other solid organ transplantations. CASE REPORT A 46-year-old male who had an orthotopic heart transplant 6 months ago presented with a 3-week history of abdominal pain. The patient described it as intermittent, sharp, and stabbing, originating in the periumbilical area and radiating to the back. His lipase was elevated at 232 U/L. Given that the patient\u27s symptoms and lipase were elevated to greater than three times the upper limit of normal, he patient was diagnosed with acute pancreatitis. The patient also mentioned a diffuse itchy rash that started a few days prior to admission. Dermatology was consulted, and given the man\u27s clinical presentation, there was concern for atypical reactivation of varicella zoster virus (VZV). VZV polymerase chain reaction of the vesicles returned positive. The patient was started on acyclovir and his symptoms improved. CONCLUSIONS This is the first reported case of VZV-associated pancreatitis in a heart transplant patient. Our patient presented with acute pancreatitis and was treated supportively. However, he did not receive antiviral treatment until his rash was discovered. Timely treatment of VZV resulted in resolution of both the rash and pancreatitis. Timely diagnosis of pancreatitis and VZV is important to prevent development of multiorgan failure and death

Continuous-flow left ventricular assist device outflow graft stenting: Indications and outcomes

Introduction: Stenosis in the continuous-flow left ventricular assist device (CF-LVAD) outflow graft can be caused by various mechanical and anatomical factors. Increasingly, percutaneous management has been utilized to re-establish adequate CF-LVAD flow. We sought to evaluate indications for such interventions and their outcomes. Methods: An electronic search was performed to identify all studies in the English literature reporting CF-LVAD outflow graft stenting for various etiologies. Twenty-one studies consisting of 26 patients were included in the analysis. Results: Median patient age was 59 years [45.8-67.0] and 65.4% (17/26) were male. 58.3% (14/24) of patients had HeartWare HVAD, 37.5% (9/24) had HeartMate II LVAD, and 4.2% (1/24) had HeartMate III LVAS. Median time from device placement to outflow graft stenting was 24.0 months [7.8-30.4]. 76.9% of patients (20/26) presented with heart failure. 34.6% (9/26) had outflow graft thrombosis, 34.6% (9/26) stenosis, 11.5% (3/26) kinking, 11.5% (3/26) pseudoaneurysm, 3.8% (1/26) external graft compression, and 3.8% (1/26) had a bronchialarterial fistula. 88.5% (23/26) procedures led to immediate flow improvement with the remaining 11.5% (3/26) receiving additional stenting. Post-intervention flows were significantly improved (4.7 L/min [4.1-4.8] post-intervention vs 2.9 L/min [2.0-3.5] initial, p=0.01). 96.2% (25/26) patients were discharged from the hospital. The 30-day mortality was 6.7% (1/15). Overall mortality during the median follow-up of 90 days [7.0-240.0] was 9.5% (2/21). Discussion: Outflow graft stenting appears to effectively alleviate CF-LVAD outflow graft obstruction with low mortality. Longer-term follow up is necessary to determine the longevity of such an intervention but early results are promising

Does Concomitant CABG Influence the Outcomes of Post-Myocardial Infarction Ventricular Septal Defect Repair?

Introduction: Ventricular septal defect (VSD) following myocardial infarction (MI) is a relatively infrequent complication with high mortality. Over time, understanding of the pathology and its management has resulted in improved outcomes; however, controversies remain. Objective: We sought to investigate the effect of concomitant coronary artery bypass graft (CABG) on outcomes following post-MI VSD repair. Methods: Electronic search was performed to identify all relevant studies published from 2000 to 2018. After assessment for inclusion and exclusion criteria, 66 studies were selected for the analysis. Data were extracted and pooled for systematic review and meta-analysis. Results: Average age was 68.7 years (95% CI 67.3-70.1) with 57% (95% CI 54-60) males. Coronary angiogram was available preoperatively in 94% (95% CI 92-96) of patients. Single-vessel disease was most common (47%, 95% CI 42-52) with left anterior descending coronary artery the most commonly involved vessel (55%, 95% CI 46-63). Concomitant CABG was performed in 52% (95% CI 46-57) of patients. Of these, infarcted territory was revascularized in 54% (95% CI 23-82). No significant survival difference was observed between those who had concomitant CABG versus those without CABG at 30 days (65%, 95% CI 58-72) vs (60%, 95% CI 47-72), 1 year (59%, 95% CI 50-68) vs (51%, 95% CI 41-61), and 5 years (46%, 95% CI 38-54) vs (39%, 95% CI 27-52) respectively. Discussion: Overall, concomitant CABG did not have a significant effect on survival following VSD repair, therefore, decision on revascularization should be weighed against the risks associated with prolonged cardiopulmonary bypass

Outcomes of Surgical Treatment for Carcinoid Heart Disease: A Systematic Review and Meta-Analysis

Introduction and Objective: Carcinoid Heart Disease (CaHD) develops from vasoactive substances released by neuroendocrine tumors causing significant patient morbidity and mortality necessitating surgical intervention. We performed a systematic review and meta-analysis to elucidate granular perioperative details and long-term outcomes in these patients. Methods: Electronic search of Ovid, Scopus, Cumulative Index of Nursing and Allied Health Literature, and Cochrane Controlled Trials Register was performed. Nine articles comprising 416 patients who received surgery were selected. Primary outcomes investigated included patient characteristics, surgical characteristics and survival data. Study-level data were extracted and pooled for meta-analysis. Results: Primary outcomes consisted of survival, length of stay and thirty-day mortality. Secondary outcomes included presence of right heart failure pre-operatively and type of valve replaced. Right heart failure was present in 48%. Moderate or severe regurgitation was present in 97% of tricuspid and 72% of pulmonary valves. 99% of tricuspid and 59% of pulmonary valves were replaced. Mean hospital length of stay was 16 days. Thirty-day mortality was 9%. Mean follow up was 25 months. Median survival was 3 years. Conclusion: Surgical treatment of CaHD can be performed with acceptable short-term outcomes. However, overall survival appears to suffer from ongoing effects of the primary disease. Surgery is often performed after patients have extensive right-sided heart involvement. Overall, onset and duration of symptoms of carcinoid heart disease should be closely monitored to properly identify and refer patients who would most benefit from valvular surgery

Endovascular Intervention for Tracheo-Innominate Fistula: A Systematic Review and Meta-analysis

Introduction: Fistula formation between the trachea and the innominate artery is a life-threatening complication rarely seen with existing or previous tracheostomy. Fatal upon rupture, swift diagnosis and immediate intervention are paramount for survival. We aim to identify feasibility and outcomes of endovascular intervention for trachea-innominate fistula (TIF). Methods: Patient-level data of reported individuals above the age of 14 that underwent endovascular intervention for TIF was extracted and analyzed. Identification of 25 patients from 27 studies was accomplished by electronic database search of Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, Ovid Medline, and Scopus. Survival data was evaluated by Kaplan-Meier analysis. Results: Median patient age was 39.0 years [IQR 16.0, 47.5]. Median time to TIF presentation following tracheostomy was 2.2 months [0.5, 42.5]. 84.6% (22/27) exhibited tracheal hemorrhage at presentation. Covered stent graft placement was performed in 96.3% (26/27) and coil embolization in 3.8% (1/27). Repeat endovascular intervention was necessary in 18.5% (5/27) and rescue sternotomy was required in 11.1% (3/27). Overall mortality was 29.6% (8/27) with a median follow-up time of 5 months [1.2, 11.5]. Discussion: Endovascular intervention may be an effective method of TIF repair at presentation. As an alternative to conventional surgical repair, endovascular intervention may be an appropriate method for TIF repair particularly in patients unfit for open sternotomy repair

Comparative performances of machine learning methods for classifying Crohn Disease patients using genome-wide genotyping data

Abstract: Crohn Disease (CD) is a complex genetic disorder for which more than 140 genes have been identified using genome wide association studies (GWAS). However, the genetic architecture of the trait remains largely unknown. The recent development of machine learning (ML) approaches incited us to apply them to classify healthy and diseased people according to their genomic information. The Immunochip dataset containing 18,227 CD patients and 34,050 healthy controls enrolled and genotyped by the international Inflammatory Bowel Disease genetic consortium (IIBDGC) has been re-analyzed using a set of ML methods: penalized logistic regression (LR), gradient boosted trees (GBT) and artificial neural networks (NN). The main score used to compare the methods was the Area Under the ROC Curve (AUC) statistics. The impact of quality control (QC), imputing and coding methods on LR results showed that QC methods and imputation of missing genotypes may artificially increase the scores. At the opposite, neither the patient/control ratio nor marker preselection or coding strategies significantly affected the results. LR methods, including Lasso, Ridge and ElasticNet provided similar results with a maximum AUC of 0.80. GBT methods like XGBoost, LightGBM and CatBoost, together with dense NN with one or more hidden layers, provided similar AUC values, suggesting limited epistatic effects in the genetic architecture of the trait. ML methods detected near all the genetic variants previously identified by GWAS among the best predictors plus additional predictors with lower effects. The robustness and complementarity of the different methods are also studied. Compared to LR, non-linear models such as GBT or NN may provide robust complementary approaches to identify and classify genetic markers

A high-precision near-infrared survey for radial velocity variable low-mass stars using CSHELL and a methane gas cell

We present the results of a precise near-infrared (NIR) radial velocity (RV) survey of 32 low-mass stars with spectral types K2-M4 using CSHELL at the NASA InfraRed Telescope Facility in the K band with an isotopologue methane gas cell to achieve wavelength calibration and a novel, iterative RV extraction method. We surveyed 14 members of young (≈25-150 Myr) moving groups, the young field star ϵ Eridani, and 18 nearby (<25 pc) low-mass stars and achieved typical single-measurement precisions of 8-15 m s-1with a long-term stability of 15-50 m s-1 over longer baselines. We obtain the best NIR RV constraints to date on 27 targets in our sample, 19 of which were never followed by high-precision RV surveys. Our results indicate that very active stars can display long-term RV variations as low as ∼25-50 m s-1 at ≈2.3125 μm, thus constraining the effect of jitter at these wavelengths. We provide the first multiwavelength confirmation of GJ 876 bc and independently retrieve orbital parameters consistent with previous studies. We recovered RV variabilities for HD 160934 AB and GJ 725 AB that are consistent with their known binary orbits, and nine other targets are candidate RV variables with a statistical significance of 3σ-5σ. Our method, combined with the new iSHELL spectrograph, will yield long-term RV precisions of ≲5 m s-1 in the NIR, which will allow the detection of super-Earths near the habitable zone of mid-M dwarfs