Distinct Transcriptomic and Proteomic Profile Specifies Patients Who Have Heart Failure With Potential of Myocardial Recovery on Mechanical Unloading and Circulatory Support.

BACKGROUND: Extensive evidence from single-center studies indicates that a subset of patients with chronic advanced heart failure (HF) undergoing left ventricular assist device (LVAD) support show significantly improved heart function and reverse structural remodeling (ie, termed "responders"). Furthermore, we recently published a multicenter prospective study, RESTAGE-HF (Remission from Stage D Heart Failure), demonstrating that LVAD support combined with standard HF medications induced remarkable cardiac structural and functional improvement, leading to high rates of LVAD weaning and excellent long-term outcomes. This intriguing phenomenon provides great translational and clinical promise, although the underlying molecular mechanisms driving this recovery are largely unknown. METHODS: To identify changes in signaling pathways operative in the normal and failing human heart and to molecularly characterize patients who respond favorably to LVAD unloading, we performed global RNA sequencing and phosphopeptide profiling of left ventricular tissue from 93 patients with HF undergoing LVAD implantation (25 responders and 68 nonresponders) and 12 nonfailing donor hearts. Patients were prospectively monitored through echocardiography to characterize their myocardial structure and function and identify responders and nonresponders. RESULTS: These analyses identified 1341 transcripts and 288 phosphopeptides that are differentially regulated in cardiac tissue from nonfailing control samples and patients with HF. In addition, these unbiased molecular profiles identified a unique signature of 29 transcripts and 93 phosphopeptides in patients with HF that distinguished responders after LVAD unloading. Further analyses of these macromolecules highlighted differential regulation in 2 key pathways: cell cycle regulation and extracellular matrix/focal adhesions. CONCLUSIONS: This is the first study to characterize changes in the nonfailing and failing human heart by integrating multiple -omics platforms to identify molecular indices defining patients capable of myocardial recovery. These findings may guide patient selection for advanced HF therapies and identify new HF therapeutic targets.

Bridge-to-transplant temporary mechanical circulatory support and risk of allosensitization.

INTRODUCTION: Since the 2018 change in the US adult heart allocation policy, more patients are bridged-to-transplant on temporary mechanical circulatory support (tMCS). Previous studies indicate that durable left ventricular assist devices (LVAD) may lead to allosensitization. The goal of this study was to assess whether tMCS implantation is associated with changes in sensitization. METHODS: We included patients evaluated for heart transplants between 2015 and 2022 who had alloantibody measured before and after MCS implantation. Allosensitization was defined as development of new alloantibodies after tMCS implant. RESULTS: A total of 41 patients received tMCS before transplant. Nine (22.0%) patients developed alloantibodies following tMCS implantation: 3 (12.0%) in the intra-aortic balloon pump group (n = 25), 2 (28.6%) in the microaxial percutaneous LVAD group (n = 7), and 4 (44.4%) in the veno-arterial extra-corporeal membrane oxygenation group (n = 9)-p = .039. Sensitized patients were younger (44.7 ± 11.6 years vs. 54.3 ± 12.5 years, p = .044), were more likely to be sensitized at baseline - 3 of 9 (33.3%) compared to 2 out of 32 (6.3%) (p = .028) and received more transfusions with red blood cells (6 (66.6%) vs. 8 (25%), p = .02) and platelets (6 (66.6%) vs. 5 (15.6%), p = .002). There was no significant difference in tMCS median duration of support (4 [3,15] days vs. 8.5 [5,14.5] days, p = .57). Importantly, out of the 11 patients who received a durable LVAD after tMCS, 5 (45.5%) became sensitized, compared to 4 out of 30 patients (13.3%) who only had tMCS-p = .028. CONCLUSIONS: Our findings suggest that patients bridged-to-transplant with tMCS, without significant blood product transfusions and a subsequent durable LVAD implant, have a low risk of allosensitization. Further studies are needed to confirm our findings and determine whether risk of sensitization varies by type of tMCS and duration of support.

The Role of Nonglycolytic Glucose Metabolism in Myocardial Recovery Upon Mechanical Unloading and Circulatory Support in Chronic Heart Failure.

BACKGROUND: Significant improvements in myocardial structure and function have been reported in some patients with advanced heart failure (termed responders [R]) following left ventricular assist device (LVAD)-induced mechanical unloading. This therapeutic strategy may alter myocardial energy metabolism in a manner that reverses the deleterious metabolic adaptations of the failing heart. Specifically, our previous work demonstrated a post-LVAD dissociation of glycolysis and oxidative-phosphorylation characterized by induction of glycolysis without subsequent increase in pyruvate oxidation through the tricarboxylic acid cycle. The underlying mechanisms responsible for this dissociation are not well understood. We hypothesized that the accumulated glycolytic intermediates are channeled into cardioprotective and repair pathways, such as the pentose-phosphate pathway and 1-carbon metabolism, which may mediate myocardial recovery in R. METHODS: We prospectively obtained paired left ventricular apical myocardial tissue from nonfailing donor hearts as well as R and nonresponders at LVAD implantation (pre-LVAD) and transplantation (post-LVAD). We conducted protein expression and metabolite profiling and evaluated mitochondrial structure using electron microscopy. RESULTS: Western blot analysis shows significant increase in rate-limiting enzymes of pentose-phosphate pathway and 1-carbon metabolism in post-LVAD R (post-R) as compared with post-LVAD nonresponders (post-NR). The metabolite levels of these enzyme substrates, such as sedoheptulose-6-phosphate (pentose phosphate pathway) and serine and glycine (1-carbon metabolism) were also decreased in Post-R. Furthermore, post-R had significantly higher reduced nicotinamide adenine dinucleotide phosphate levels, reduced reactive oxygen species levels, improved mitochondrial density, and enhanced glycosylation of the extracellular matrix protein, α-dystroglycan, all consistent with enhanced pentose-phosphate pathway and 1-carbon metabolism that correlated with the observed myocardial recovery. CONCLUSIONS: The recovering heart appears to direct glycolytic metabolites into pentose-phosphate pathway and 1-carbon metabolism, which could contribute to cardioprotection by generating reduced nicotinamide adenine dinucleotide phosphate to enhance biosynthesis and by reducing oxidative stress. These findings provide further insights into mechanisms responsible for the beneficial effect of glycolysis induction during the recovery of failing human hearts after mechanical unloading.

Predicting mortality in cardiogenic shock secondary to ACS requiring short-term mechanical circulatory support: The ACS-MCS score.

OBJECTIVE: To identify predictors of 30-day all-cause mortality for patients with cardiogenic shock secondary to acute coronary syndrome (ACS-CS) who require short-term mechanical circulatory support (ST-MCS). BACKGROUND: ACS-CS mortality is high. ST-MCS is an attractive treatment option for hemodynamic support and stabilization of deteriorating patients. Mortality prediction modeling for ACS-CS patients requiring ST-MCS has not been well-defined. METHODS: The Utah Cardiac Recovery (UCAR) Shock database was used to identify patients admitted with ACS-CS requiring ST-MCS devices between May 2008 and August 2018. Pre-ST-MCS clinical, laboratory, echocardiographic, and angiographic data were collected. The primary endpoint was 30-day all-cause mortality. A weighted score comprising of pre-ST-MCS variables independently associated with 30-day all-cause mortality was derived and internally validated. RESULTS: A total of 159 patients (mean age, 61 years; 78% male) were included. Thirty-day all-cause mortality was 49%. Multivariable analysis resulted in four independent predictors of 30-day all-cause mortality: age, lactate, SCAI CS classification, and acute kidney injury. The model had good calibration and discrimination (area under the receiver operating characteristics curve 0.80). A predictive score (ranging 0-4) comprised of age ≥ 60 years, pre-ST-MCS lactate ≥2.5 mmol/L, AKI at time of ST-MCS implementation, and SCAI CS stage E effectively risk stratified our patient population. CONCLUSION: The ACS-MCS score is a simple and practical predictive score to risk-stratify CS secondary to ACS patients based on their mortality risk. Effective mortality risk assessment for ACS-CS patients could have implications on patient selection for available therapeutic strategy options.

Outcomes of Asian-Americans Implanted With Left Ventricular Assist Devices: An Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) Analysis.

BACKGROUND: Studies have indicated differences between Asians and Whites in their propensity for stroke, coronary artery disease, heart failure, bleeding and thrombosis. We investigated whether Asian-Americans on durable left ventricular assist devices (LVADs) exhibit differential morbidity and mortality when compared to Whites. METHODS: We analysed prospectively collected data from the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database to compare the outcomes after LVAD implantation of Asians versus Whites. RESULTS: In total, 7,018 patients were included, 130 were identified as Asian-Americans. Asian-Americans were younger, had lower body mass index, higher serum bilirubin and lower albumin levels. In a multivariable regression model, there was no difference in survival between the two groups. Asian-Americans had lower incidence of device malfunction and after adjusting for multiple factors this remained lower. The adjusted risk of a major safety composite outcome, including major bleeding, major infection, stroke and device malfunction, revealed no difference between the two groups. CONCLUSIONS: Although prior studies have reported worse cardiac surgery outcomes in Asians, in this INTERMACS analysis Asian-Americans appear to have similar survival and risk of adverse events as their White counterparts. The incidence of device malfunction was lower in the Asian-Americans, both in a univariate model and after adjusting for multiple clinical factors. Future, larger studies of Asian-Americans with end-stage heart failure and LVAD support are warranted to confirm these results.

Patterns of cardiac dysfunction after carbon monoxide poisoning.

Objective: To describe the structural sequelae of carbon monoxide (CO) poisoning on the heart assessed using stress cardiac MRI (CMR). CO poisoning is common. While acute cardiac injury is frequent among survivors, the mid- and long-term effects of CO on the myocardium are unclear. Methods: CMR studies performed between the years 2005 and 2014 for a primary diagnosis of CO poisoning at a tertiary care center were reviewed by an experienced cardiologist. Variables of interest were compared between patients with normal and abnormal studies to identify factors associated with cardiac dysfunction. Results: Eighty-eight patients underwent stress CMR, age 34 years (range 11-70); 49% were male, 74 had acute poisoning and 14 had chronic poisoning (CO exposure for longer than 24 hours). Time from CO poisoning to imaging was 24 months (1 day-120 months). Patients were stratified into four categories, which included those with acute poisoning imaged: ≤12 months; 12-60 months; >60 months from the event; and those with chronic poisoning. Overall, 26 studies (30%) were abnormal. The most common findings were: left ventricular systolic dysfunction in 14 patients, right ventricular systolic dysfunction in nine, and LV dilatation in six. Abnormalities were mild in most cases and were equally prevalent in all four patient categories. Dyspnea at the time of follow-up was more frequent among those with abnormal studies. Conclusion: Mild alterations in ventricular structure and function are frequent in survivors of CO poisoning. Myocardial scarring is rare, suggesting that acute hypoxic injury may not fully explain these abnormalities.

DNA methylation reprograms cardiac metabolic gene expression in end-stage human heart failure.

Heart failure (HF) is a leading cause of morbidity and mortality in the United States and worldwide. As a multifactorial syndrome with unpredictable clinical outcomes, identifying the common molecular underpinnings that drive HF pathogenesis remains a major focus of investigation. Disruption of cardiac gene expression has been shown to mediate a common final cascade of pathological hallmarks wherein the heart reactivates numerous developmental pathways. Although the central regulatory mechanisms that drive this cardiac transcriptional reprogramming remain unknown, epigenetic contributions are likely. In the current study, we examined whether the epigenome, specifically DNA methylation, is reprogrammed in HF to potentiate a pathological shift in cardiac gene expression. To accomplish this, we used paired-end whole genome bisulfite sequencing and next-generation RNA sequencing of left ventricle tissue obtained from seven patients with end-stage HF and three nonfailing donor hearts. We found that differential methylation was localized to promoter-associated cytosine-phosphate-guanine islands, which are established regulatory regions of downstream genes. Hypermethylated promoters were associated with genes involved in oxidative metabolism, whereas promoter hypomethylation enriched glycolytic pathways. Overexpression of plasmid-derived DNA methyltransferase 3A in vitro was sufficient to lower the expression of numerous oxidative metabolic genes in H9c2 rat cardiomyoblasts, further supporting the importance of epigenetic factors in the regulation of cardiac metabolism. Last, we identified binding-site competition via hypermethylation of the nuclear respiratory factor 1 (NRF1) motif, an established upstream regulator of mitochondrial biogenesis. These preliminary observations are the first to uncover an etiology-independent shift in cardiac DNA methylation that corresponds with altered metabolic gene expression in HF.NEW & NOTEWORTHY The failing heart undergoes profound metabolic changes because of alterations in cardiac gene expression, reactivating glycolytic genes and suppressing oxidative metabolic genes. In the current study, we discover that alterations to cardiac DNA methylation encode this fetal-like metabolic gene reprogramming. We also identify novel epigenetic interference of nuclear respiratory factor 1 via hypermethylation of its downstream promoter targets, further supporting a novel contribution of DNA methylation in the metabolic remodeling of heart failure.

Team-based Care for Advanced Heart Failure.

Advanced heart failure (AHF) is the late stage of the heart failure syndrome that is associated with significant morbidity, high mortality, and rising costs that pose a significant burden for the different health care systems in the United States and worldwide. Despite advances in pharmacologic and device therapy, patients with AHF frequently require complex therapies, such as continuous infusion with inotropic agents, mechanical circulatory support, and heart transplant. This article summarizes the team-based approach to care of patients with AHF and those supported by left ventricular assist devices.

Morbidity and mortality in heart transplant candidates supported with mechanical circulatory support: is reappraisal of the current United network for organ sharing thoracic organ allocation policy justified?

BACKGROUND: Survival of patients on left ventricular assist devices (LVADs) has improved. We examined the differences in risk of adverse outcomes between LVAD-supported and medically managed candidates on the heart transplant waiting list. METHODS AND RESULTS: We analyzed mortality and morbidity in 33,073 heart transplant candidates registered on the United Network for Organ Sharing (UNOS) waiting list between 1999 and 2011. Five groups were selected: patients without LVADs in urgency status 1A, 1B, and 2; patients with pulsatile-flow LVADs; and patients with continuous-flow LVADs. Outcomes in patients requiring biventricular assist devices, total artificial heart, and temporary VADs were also analyzed. Two eras were defined on the basis of the approval date of the first continuous-flow LVAD for bridge to transplantation in the United States (2008). Mortality was lower in the current compared with the first era (2.1%/mo versus 2.9%/mo; P<0.0001). In the first era, mortality of pulsatile-flow LVAD patients was higher than in status 2 (hazard ratio [HR], 2.15; P<0.0001) and similar to that in status 1B patients (HR, 1.04; P=0.61). In the current era, patients with continuous-flow LVADs had mortality similar to that of status 2 (HR, 0.80; P=0.12) and lower mortality compared with status 1A and 1B patients (HR, 0.24 and 0.47; P<0.0001 for both comparisons). However, status upgrade for LVAD-related complications occurred frequently (28%) and increased the mortality risk (HR, 1.75; P=0.001). Mortality was highest in patients with biventricular assist devices (HR, 5.00; P<0.0001) and temporary VADs (HR, 7.72; P<0.0001). CONCLUSIONS: Mortality and morbidity on the heart transplant waiting list have decreased. Candidates supported with contemporary continuous-flow LVADs have favorable waiting list outcomes; however, they worsen significantly once a serious LVAD-related complication occurs. Transplant candidates requiring temporary and biventricular support have the highest risk of adverse outcomes. These results may help to guide optimal allocation of donor hearts.

Characterization of diffuse fibrosis in the failing human heart via diffusion tensor imaging and quantitative histological validation.

Non-invasive imaging techniques are highly desirable as an alternative to conventional biopsy for the characterization of the remodeling of tissues associated with disease progression, including end-stage heart failure. Cardiac diffusion tensor imaging (DTI) has become an established method for the characterization of myocardial microstructure. However, the relationships between diffuse myocardial fibrosis, which is a key biomarker for staging and treatment planning of the failing heart, and measured DTI parameters have yet to be investigated systematically. In this study, DTI was performed on left ventricular specimens collected from patients with chronic end-stage heart failure as a result of idiopathic dilated cardiomyopathy (n = 14) and from normal donors (n = 5). Scalar DTI parameters, including fractional anisotropy (FA) and mean (MD), primary (D1 ), secondary (D2 ) and tertiary (D3 ) diffusivities, were correlated with collagen content measured by digital microscopy. Compared with hearts from normal subjects, the FA in failing hearts decreased by 22%, whereas the MD, D2 and D3 increased by 12%, 14% and 24%, respectively (P < 0.01). No significant change was detected for D1 between the two groups. Furthermore, significant correlation was observed between the DTI scalar indices and quantitative histological measurements of collagen (i.e. fibrosis). Pearson's correlation coefficients (r) between collagen content and FA, MD, D2 and D3 were -0.51, 0.59, 0.56 and 0.62 (P < 0.05), respectively. The correlation between D1 and collagen content was not significant (r = 0.46, P = 0.05). Computational modeling analysis indicated that the behaviors of the DTI parameters as a function of the degree of fibrosis were well explained by compartmental exchange between myocardial and collagenous tissues. Combined, these findings suggest that scalar DTI parameters can be used as metrics for the non-invasive assessment of diffuse fibrosis in failing hearts.

Impact of Diabetes and Glycemia on Cardiac Improvement and Adverse Events Following Mechanical Circulatory Support.

BACKGROUND: Type 2 diabetes is prevalent in cardiovascular disease and contributes to excess morbidity and mortality. We sought to investigate the effect of glycemia on functional cardiac improvement, morbidity, and mortality in durable left ventricular assist device (LVAD) recipients. METHODS AND RESULTS: Consecutive patients with an LVAD were prospectively evaluated (n=531). After excluding patients missing pre-LVAD glycated hemoglobin (HbA1c) measurements or having inadequate post-LVAD follow-up, 375 patients were studied. To assess functional cardiac improvement, we used absolute left ventricular ejection fraction change (ΔLVEF: LVEF post-LVAD-LVEF pre-LVAD). We quantified the association of pre-LVAD HbA1c with ΔLVEF as the primary outcome, and all-cause mortality and LVAD-related adverse event rates (ischemic stroke/transient ischemic attack, intracerebral hemorrhage, gastrointestinal bleeding, LVAD-related infection, device thrombosis) as secondary outcomes. Last, we assessed HbA1c differences pre- and post-LVAD. Patients with type 2 diabetes were older, more likely men suffering ischemic cardiomyopathy, and had longer heart failure duration. Pre-LVAD HbA1c was inversely associated with ΔLVEF in patients with nonischemic cardiomyopathy but not in those with ischemic cardiomyopathy, after adjusting for age, sex, heart failure duration, and left ventricular end-diastolic diameter. Pre-LVAD HbA1c was not associated with all-cause mortality, but higher pre-LVAD HbA1c was shown to increase the risk of intracerebral hemorrhage, LVAD-related infection, and device thrombosis by 3 years on LVAD support (P<0.05 for all). HbA1c decreased from 6.68±1.52% pre-LVAD to 6.11±1.33% post-LVAD (P<0.001). CONCLUSIONS: Type 2 diabetes and pre-LVAD glycemia modify the potential for functional cardiac improvement and the risk for adverse events on LVAD support. The degree and duration of pre-LVAD glycemic control optimization to favorably affect these outcomes warrants further investigation.

Cardiac Reverse Remodeling Mediated by HeartMate 3 Left Ventricular Assist Device: Comparison to Older Generation Devices.

Currently, the fully magnetically levitated left ventricular assist device (LVAD) HeartMate 3 (HM3) is the only commercially available device for advanced heart failure (HF) patients. However, the left ventricular (LV) functional and structural changes following mechanical unloading and circulatory support (MCS) with the HM3 have not been investigated. We compared the reverse remodeling induced by the HM3 to older generation continuous-flow LVADs. Chronic HF patients (n = 405) undergoing MCS with HeartWare Ventricular Assist Device (HVAD, n = 115), HM3 (n = 186), and HeartMate II (HM2, n = 104) at four programs were included. Echocardiograms were obtained preimplant and at 1, 3, 6, and 12 months following LVAD implantation. There were no differences in the postimplant serial LV ejection fraction (LVEF) between the devices. The postimplant LV internal diastolic diameter (LVIDd) was significantly lower for HM2 at 3 and 6 months compared with HVAD and HM3. The proportion of patients achieving "cardiac reverse remodeling responder" status (defined as LVEF improvement to ≥40% and LVIDD ≤5.9 cm) was 11.9%, and was similar between devices. HeartMate 3 appears to result in similar cardiac reverse remodeling as older generation CF-LVADs, suggesting that the fully magnetically levitated device technology could provide an effective platform to further study and promote cardiac reverse remodeling.

Safety and Efficacy of Metabolic Modulation With Ninerafaxstat in Patients With Nonobstructive Hypertrophic Cardiomyopathy.

BACKGROUND: In nonobstructive hypertrophic cardiomyopathy (nHCM), there are no approved medical therapies. Impaired myocardial energetics is a potential cause of symptoms and exercise limitation. Ninerafaxstat, a novel cardiac mitotrope, enhances cardiac energetics. OBJECTIVES: This study sought to evaluate the safety and efficacy of ninerafaxstat in nHCM. METHODS: Patients with hypertrophic cardiomyopathy and left ventricular outflow tract gradient <30 mm Hg, ejection fraction ≥50%, and peak oxygen consumption <80% predicted were randomized to ninerafaxstat 200 mg twice daily or placebo (1:1) for 12 weeks. The primary endpoint was safety and tolerability, with efficacy outcomes also assessed as secondary endpoints. RESULTS: A total of 67 patients with nHCM were enrolled at 12 centers (57 ± 11.8 years of age; 55% women). Serious adverse events occurred in 11.8% (n = 4 of 34) in the ninerafaxstat group and 6.1% (n = 2 of 33) of patients in the placebo group. From baseline to 12 weeks, ninerafaxstat was associated with significantly better VE/Vco2 (ventilatory efficiency) slope compared with placebo with a least-squares (LS) mean difference between the groups of -2.1 (95% CI: -3.6 to -0.6; P = 0.006), with no significant difference in peak VO2 (P = 0.90). The Kansas City Cardiomyopathy Questionnaire Clinical Summary Score was directionally, though not significantly, improved with ninerafaxstat vs placebo (LS mean 3.2; 95% CI: -2.9 to 9.2; P = 0.30); however, it was statistically significant when analyzed post hoc in the 35 patients with baseline Kansas City Cardiomyopathy Questionnaire Clinical Summary Score ≤80 (LS mean 9.4; 95% CI: 0.3-18.5; P = 0.04). CONCLUSIONS: In symptomatic nHCM, novel drug therapy targeting myocardial energetics was safe and well tolerated and associated with better exercise performance and health status among those most symptomatically limited. The findings support assessing ninerafaxstat in a phase 3 study.

Machine Learning Multicenter Risk Model to Predict Right Ventricular Failure After Mechanical Circulatory Support: The STOP-RVF Score.

Importance: The existing models predicting right ventricular failure (RVF) after durable left ventricular assist device (LVAD) support might be limited, partly due to lack of external validation, marginal predictive power, and absence of intraoperative characteristics. Objective: To derive and validate a risk model to predict RVF after LVAD implantation. Design, Setting, and Participants: This was a hybrid prospective-retrospective multicenter cohort study conducted from April 2008 to July 2019 of patients with advanced heart failure (HF) requiring continuous-flow LVAD. The derivation cohort included patients enrolled at 5 institutions. The external validation cohort included patients enrolled at a sixth institution within the same period. Study data were analyzed October 2022 to August 2023. Exposures: Study participants underwent chronic continuous-flow LVAD support. Main Outcome and Measures: The primary outcome was RVF incidence, defined as the need for RV assist device or intravenous inotropes for greater than 14 days. Bootstrap imputation and adaptive least absolute shrinkage and selection operator variable selection techniques were used to derive a predictive model. An RVF risk calculator (STOP-RVF) was then developed and subsequently externally validated, which can provide personalized quantification of the risk for LVAD candidates. Its predictive accuracy was compared with previously published RVF scores. Results: The derivation cohort included 798 patients (mean [SE] age, 56.1 [13.2] years; 668 male [83.7%]). The external validation cohort included 327 patients. RVF developed in 193 of 798 patients (24.2%) in the derivation cohort and 107 of 327 patients (32.7%) in the validation cohort. Preimplant variables associated with postoperative RVF included nonischemic cardiomyopathy, intra-aortic balloon pump, microaxial percutaneous left ventricular assist device/venoarterial extracorporeal membrane oxygenation, LVAD configuration, Interagency Registry for Mechanically Assisted Circulatory Support profiles 1 to 2, right atrial/pulmonary capillary wedge pressure ratio, use of angiotensin-converting enzyme inhibitors, platelet count, and serum sodium, albumin, and creatinine levels. Inclusion of intraoperative characteristics did not improve model performance. The calculator achieved a C statistic of 0.75 (95% CI, 0.71-0.79) in the derivation cohort and 0.73 (95% CI, 0.67-0.80) in the validation cohort. Cumulative survival was higher in patients composing the low-risk group (estimated <20% RVF risk) compared with those in the higher-risk groups. The STOP-RVF risk calculator exhibited a significantly better performance than commonly used risk scores proposed by Kormos et al (C statistic, 0.58; 95% CI, 0.53-0.63) and Drakos et al (C statistic, 0.62; 95% CI, 0.57-0.67). Conclusions and Relevance: Implementing routine clinical data, this multicenter cohort study derived and validated the STOP-RVF calculator as a personalized risk assessment tool for the prediction of RVF and RVF-associated all-cause mortality.

Integrating molecular and clinical variables to predict myocardial recovery.

Mechanical unloading and circulatory support with left ventricular assist devices (LVADs) mediate significant myocardial improvement in a subset of advanced heart failure (HF) patients. The clinical and biological phenomena associated with cardiac recovery are under intensive investigation. Left ventricular (LV) apical tissue, alongside clinical data, were collected from HF patients at the time of LVAD implantation (n=208). RNA was isolated and mRNA transcripts were identified through RNA sequencing and confirmed with RT-qPCR. To our knowledge this is the first study to combine transcriptomic and clinical data to derive predictors of myocardial recovery. We used a bioinformatic approach to integrate 59 clinical variables and 22,373 mRNA transcripts at the time of LVAD implantation for the prediction of post-LVAD myocardial recovery defined as LV ejection fraction (LVEF) ≥40% and LV end-diastolic diameter (LVEDD) ≤5.9cm, as well as functional and structural LV improvement independently by using LVEF and LVEDD as continuous variables, respectively. To substantiate the predicted variables, we used a multi-model approach with logistic and linear regressions. Combining RNA and clinical data resulted in a gradient boosted model with 80 features achieving an AUC of 0.731±0.15 for predicting myocardial recovery. Variables associated with myocardial recovery from a clinical standpoint included HF duration, pre-LVAD LVEF, LVEDD, and HF pharmacologic therapy, and LRRN4CL (ligand binding and programmed cell death) from a biological standpoint. Our findings could have diagnostic, prognostic, and therapeutic implications for advanced HF patients, and inform the care of the broader HF population.

Dual chamber pacing relieves obstruction in Japanese-variant hypertrophic cardiomyopathy.

Japanese-variant or apical hypertrophic cardiomyopathy (HCM) is a specific type of HCM, first described in Japan and initially thought to carry a benign prognosis. However, current evidence suggests that these patients experience severe symptoms and are at increased risk of ventricular arrhythmias and death, especially in the presence of an apical akinetic chamber. The management of patients who do not respond to medical therapy is challenging. We describe a patient with Japanese-variant HCM, with an apical akinetic chamber and severe symptoms who failed medical therapy. The use of dual chamber pacing relieved obstruction and significantly improved the patient's symptoms.

Recovery With Temporary Mechanical Circulatory Support While Waitlisted for Heart Transplantation.

BACKGROUND: The 2018 U.S. heart allocation system offers an accelerated pathway for heart transplantation to the most urgent patients. OBJECTIVES: This study sought to determine whether the new allocation system resulted in lower likelihood of candidate recovery. METHODS: Adult patients waitlisted for heart transplantation with temporary mechanical circulatory support at the time of initial listing between 2010 and 2020 in the United Network for Organ Sharing registry were included. Competing events of heart transplantation, waitlist death or delisting for deteriorating condition, and delisting for improved condition (candidate recovery) were analyzed in the new vs old heart allocation system. RESULTS: A total of 688 patients were waitlisted with venoarterial extracorporeal membrane oxygenation or a surgical nondischargeable biventricular assist device (status 1 or old 1A). Overall, 2,237 patients were waitlisted with an intra-aortic balloon pump, a percutaneous left ventricular assist device (LVAD), or a surgical nondischargeable LVAD (status 2 or old 1A). Patients waitlisted with venoarterial extracorporeal membrane oxygenation or a nondischargeable biventricular assist device had significantly shorter median waitlist times (5 vs 31 days), higher incidence for cardiac transplantation (81.5% vs 43.0%), and lower incidence of candidate recovery (1.5% vs 7.9%) in the new vs old heart allocation system (all P < 0.05). Patients waitlisted with an intra-aortic balloon pump or percutaneous or a nondischargeable LVAD also had significantly shorter median waitlist times (8 vs 35 days), higher incidence of transplantation (88.9% vs 64.9%), and lower incidence of candidate recovery (0.2% vs 1.6%) in the new vs old heart allocation system (all P < 0.05). CONCLUSIONS: Current practice of the new allocation system may not offer select temporary mechanical circulatory support patients the opportunity and adequate time to recover to the point of waitlist removal. Further research will determine which patients would benefit from urgent transplantation vs recovery strategy.