BACKGROUND: Among accepted US heart organs, listing centers accept organ offers earliest for White women, followed by Black women, White men, and Black men. Understanding the relationships of center- and geographic-level decisions is necessary to understand waitlist disparities. We sought to determine whether listing center and geography are associated with the first heart organ acceptance by candidate race, since race demographics vary regionally across the United States. METHODS: Using the United Network for Organ Sharing data sets, we identified first organ offers for Black and White candidates listed for heart transplant (October 18, 2018 to September 30, 2024) and compared models with and without listing center effects adjusted for candidate-, donor-, and offer-level variables. RESULTS: Among 20 668 candidates (31.6% Black, 68.4% White, 26.5% women), the adjusted odds of first offer acceptance were lower for Black candidates compared with White candidates (odds ratio, 0.84 [95% CI, 0.76–0.94]; P =0.001) when listing center was not included in the model; but after adjusting for listing center effects, odds were similar by race (odds ratio, 0.98 [95% CI, 0.88–1.10]; P =0.78). There were no clear geographic patterns by center, but centers with lower proportions of Black candidates had higher acceptance rates. CONCLUSIONS: Variability in overall acceptance rate among listing centers explains the lower first offer acceptance for Black compared with White heart candidates. Baseline acceptance rates were linked to the center-level proportion of Black candidates but not geography. Investigation of strategies to systemically improve early acceptance of good heart organs may reduce Black and White disparities in wait time duration.
The ALT FLOW early feasibility study 3-year results assessing left atrial to coronary sinus shunting in HFpEF
Abstract Introduction Left atrial-to-coronary sinus (LA-to-CS) shunting through the APTURE transcatheter shunt system aims to unload the LA while preserving the interatrial septum. This article aims to examine the 3-year health status, functional capacity, and clinical outcomes of the ALT-FLOW Early Feasibility Study (EFS). Methods Device safety, patency, and echocardiographic parameters, but also symptoms, health status, and exercise capacity were assessed in patients with left ventricular ejection fraction (LVEF) > 40% (n & 95). Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) score predicted 3-year all-cause mortality was compared with observed mortality assessed by Kaplan–Meier analysis using adjudicated events. Predicted and observed HF hospitalization (HFH)-free survival rates were also compared. Results At 3 years, the safety profile remained stable with no new safety signals, and all implanted shunts remained patent. 76.3% of patients improved by at least one NYHA class, and mean KCCQ Overall Summary Scores increased by 25 points from baseline (P < .0001). The 6-min walk distance improved by an average of 39 m (P & .002). These benefits were consistent regardless of baseline pulmonary vascular resistance (PVR). Right heart echocardiographic parameters after 3 years were stable, though a reduction in TAPSE was observed, primarily in the high PVR subgroup. The observed 3-year survival was significantly higher than the MAGGIC-predicted survival (84.4% vs 70.2, respectively; P & .009), as well as the HFH-free survival (68.0% vs 24.0%, respectively; P < 0001). Conclusion In patients with HF and LVEF >40%, the APTURE LA-to-CS shunting confirmed an acceptable safety profile with stable right heart parameters and sustained improvements in symptoms, quality of life, and functional capacity at 3 years. Observed survival and HFH were superior to MAGGIC predictions.
Rationale and design of a randomized, sham-controlled, clinical trial for evaluation of the Edwards APTURE transcatheter shunt system (ALT-FLOW II)
Abstract Aims Heart failure (HF) with preserved (HFpEF) and mildly reduced (HFmrEF) ejection fraction are prevalent, yet frequently underdiagnosed syndromes associated with high morbidity and mortality, impaired quality of life, and escalating healthcare expenditures. Although guideline-directed medications like SGLT2 inhibitors have been shown to reduce the risk of hospitalization and cardiovascular death, their use remains limited and substantial residual risk persists. This trial aims to evaluate the safety and performance of a novel left-atrium-to-coronary-sinus shunt (Edwards APTURE transcatheter shunt system) in HFpEF and HFmrEF patients. Methods ALT-FLOW II is a prospective multi-centre, randomized, sham-controlled, double-blinded (patient and assessor) trial. Approximately 100 symptomatic HF patients aged ≥18 years with left ventricular ejection fraction >40% and exercise pulmonary capillary wedge pressure (PCWP) ≥25 mm Hg with a PCWP to right atrial pressure gradient ≥8 mm Hg will be randomized 1:1 to the APTURE shunt vs sham control. Key exclusion criteria include severe HF, significant valvular disease, and more than mild right ventricular dysfunction. The primary endpoints are the safety of the APTURE device at 30 days and change in workload-corrected PCWP normalized to bodyweight at 6 months. Secondary endpoints include changes in patient-reported outcomes, and hemodynamic and echocardiographic parameters through 5 years. The trial will also explore the impact of the device on short-term cardiac remodelling and intra-cardiac flow patterns using multi-modality imaging. Conclusions The ALT-FLOW II trial will evaluate the safety and performance of the APTURE system in symptomatic HFpEF and HFmrEF patients with elevated left atrial pressure.
Personalizing Mechanical Circulatory Support for Cardiogenic Shock: A Review and Comparison of Current Devices
ABSTRACT Cardiogenic shock (CS) remains a high morbidity and mortality condition worldwide frequently complicating acute myocardial infarction (AMI) and decompensated heart failure (HF). Within the management of CS, mechanical circulatory support (MCS) devices play a critical role in maintaining hemodynamic stability, preserving end‐organ perfusion and bridging patients through to recovery, implantation of durable support or transplantation. Despite their use, optimal timing of initiation, as well as patient and device selection remain unclear. This review explores the current landscape of MCS devices, surrounding evidence and key distinctions between devices. With increasing acknowledgment for the heterogeneity of CS, understanding the strengths and limitations of each device remains crucial to improving outcomes in this high‐risk population.
Dysregulated Tricarboxylic Acid Cycle Metabolism Is Associated With Right Ventricular Maladaptation in Pulmonary Vascular Disease
Background Right ventricular (RV) maladaptation to elevated pulmonary afterload is the primary determinant of outcomes in pulmonary artery (PA) hypertension; however, the pathobiological mechanisms underlying RV decompensation remain poorly understood. Methods We performed global untargeted metabolomics on plasma from 55 patients who underwent gold‐standard RV‐PA coupling measurements using multibeat pressure volume loop assessment in a single‐center cohort and from 1027 patients with coupling surrogate measurements in a larger multicenter cohort, the PVDOMICS (Pulmonary Vascular Disease Phenomics) study. Age and sex‐adjusted linear regression was performed to identify associations between metabolites and coupling metrics. Additionally, we performed a metabolic flux analysis using gene expression data from RV tissue in an independent cohort of 32 patients. Partial least squares–discriminant analysis was used to identify metabolites and reactions characteristic of the decompensated RV. Results RV‐PA coupling was negatively associated with tricarboxylic acid (TCA) cycle intermediate levels. Specifically, plasma α‐ketoglutarate and fumarate were significantly associated with all coupling metrics in both cohorts. Metabolic flux analysis indicated that decompensated RVs exhibited aberrant TCA cycle activity, including reduced acetyl coenzyme A entry and increased lactate elimination, suggesting a shift from the TCA cycle toward glycolysis at the RV tissue level. Conclusions We identify an association between circulating TCA cycle intermediate levels and RV‐PA uncoupling in 2 independent cohorts, and dysregulated TCA cycle metabolism in decompensated PA hypertension RVs, suggesting that aberrant TCA cycle metabolism could represent a hallmark of RV maladaptation in PA hypertension. Further study of this pathway is warranted to develop novel biomarkers of RV function or RV‐targeted therapies.
Evidence-Based Application of Natriuretic Peptides in the Evaluation of Chronic Heart Failure With Preserved Ejection Fraction in the Ambulatory Outpatient Setting
BACKGROUND: Plasma NT-proBNP (N-terminal pro-B-type natriuretic peptide) is commonly used to diagnose heart failure with preserved ejection fraction (HFpEF), but its diagnostic performance in the ambulatory/outpatient setting is unknown because previous studies lacked objective reference standards. METHODS: Among patients with chronic dyspnea, diagnosis of HFpEF or noncardiac dyspnea was determined conclusively by exercise catheterization in a derivation cohort (n=414), multicenter validation cohort 1 (n=560), validation cohort 2 (n=207), and a nonobese Japanese validation cohort 3 (n=77). Optimal NT-proBNP cut points for HFpEF rule out (optimizing sensitivity) and rule in (optimizing specificity) were derived and tested, stratified by obesity and atrial fibrillation. Derived cut points were tested in 3 additional validation cohorts (cohorts 4–6) in whom HFpEF was diagnosed by resting catheterization only (n=260), previous hospitalization for heart failure (n=447), or exercise echocardiography (n=517), respectively. RESULTS: Current recommended rule-out NT-proBNP threshold <125 pg/mL had 82% sensitivity (95% CI, 77%–88%) with a body mass index (BMI) <35 kg/m 2 , decreasing to 67% (95% CI, 58%–77%) with a BMI ≥35 kg/m 2 . A lower rule-out NT-proBNP threshold <50 pg/mL displayed good sensitivity with a BMI <35 kg/m 2 (97% [95% CI, 95%–99%]), with a modest decline in sensitivity with a BMI ≥35 kg/m 2 (86% [95% CI, 79%–93%]); diagnostic thresholds were confirmed in validation cohorts 1 and 2 (91% [95% CI, 88%–95%] and 86% [95% CI, 80%–93%] with a BMI <35 kg/m 2 ; 80% [95% CI, 74%–87%] and 84% [95% CI, 74%–93%] with a BMI ≥35 kg/m 2 ). Current consensus age- and BMI-stratified rule-in thresholds demonstrated only 65% specificity (95% CI, 57%–72%). Rule-in NT-proBNP threshold ≥500 pg/mL had 85% specificity (95% CI, 78%–91%) with a BMI <35 kg/m 2 (87% [95% CI, 80%–94%] and 90% [95% CI, 81%–99%] in validation cohorts), with 100% specificity at a BMI ≥35 kg/m 2 (93% [95% CI, 81%–100%] and 100% in validation cohorts). With a BMI ≥35 kg/m 2 , lower rule-in thresholds (≥220 pg/mL) provided good specificity (88% [95% CI, 73%–100%]; 93% [95% CI, 81%–100%] and 100% in validation cohorts). Findings were consistent in validation cohorts 3 through 6 (sensitivity of <50 pg/mL, 93%–98%; specificity of ≥500 pg/mL, 82%–89%). NT-proBNP provided no incremental discrimination among patients with history of AF; ≥98% of patients with AF and dyspnea were found to have HFpEF in our cohorts. CONCLUSIONS: In patients with chronic unexplained dyspnea, current rule-in and rule-out NT-proBNP diagnostic thresholds lead to unacceptably high error rates, with important interactions by obesity and AF status. In our study, NT-proBNP provided little value in those with AF and dyspnea because the presence of AF is by itself a robust biomarker of HFpEF. Use of separate rule-in and rule-out diagnostic thresholds stratified by BMI reduces miscategorization and can guide more appropriate use of exercise testing for possible HFpEF.
Invasive Right Ventricular Pressure-Volume Analysis: Basic Principles, Clinical Applications, and Practical Recommendations
Right ventricular pressure-volume (PV) analysis characterizes ventricular systolic and diastolic properties independent of loading conditions like volume status and afterload. While long-considered the gold-standard method for quantifying myocardial chamber performance, it was traditionally only performed in highly specialized research settings. With recent advances in catheter technology and more sophisticated approaches to analyze PV data, it is now more commonly used in a variety of clinical and research settings. Herein, we review the basic techniques for PV loop measurement, analysis, and interpretation with the aim of providing readers with a deeper understanding of the strengths and limitations of PV analysis. In the second half of the review, we detail key scenarios in which right ventricular PV analysis has influenced our understanding of clinically relevant topics and where the technique can be applied to resolve additional areas of uncertainty. All told, PV analysis has an important role in advancing our understanding of right ventricular physiology and its contribution to cardiovascular function in health and disease.
Pulmonary Capillary Wedge Pressure Augments Right Ventricular Pulsatile Loading
Background— Right ventricular failure from increased pulmonary vascular loading is a major cause of morbidity and mortality, yet its modulation by disease remains poorly understood. We tested the hypotheses that, unlike the systemic circulation, pulmonary vascular resistance (R PA ) and compliance (C PA ) are consistently and inversely related regardless of age, pulmonary hypertension, or interstitial fibrosis and that this relation may be changed by elevated pulmonary capillary wedge pressure, augmenting right ventricular pulsatile load. Methods and Results— Several large clinical databases with right heart/pulmonary catheterization data were analyzed to determine the R PA -C PA relationship with pulmonary hypertension, pulmonary fibrosis, patient age, and varying pulmonary capillary wedge pressure. Patients with suspected or documented pulmonary hypertension (n=1009) and normal pulmonary capillary wedge pressure displayed a consistent R PA -C PA hyperbolic (inverse) dependence, C PA =0.564/(0.047+R PA ), with a near-constant resistance-compliance product (0.48±0.17 seconds). In the same patients, the systemic resistance-compliance product was highly variable. Severe pulmonary fibrosis (n=89) did not change the R PA -C PA relation. Increasing patient age led to a very small but statistically significant change in the relation. However, elevation of the pulmonary capillary wedge pressure (n=8142) had a larger impact, significantly lowering C PA for any R PA and negatively correlating with the resistance-compliance product ( P <0.0001). Conclusions— Pulmonary hypertension and pulmonary fibrosis do not significantly change the hyperbolic dependence between R PA and C PA , and patient age has only minimal effects. This fixed relationship helps explain the difficulty of reducing total right ventricular afterload by therapies that have a modest impact on mean R PA . Higher pulmonary capillary wedge pressure appears to enhance net right ventricular afterload by elevating pulsatile, relative to resistive, load and may contribute to right ventricular dysfunction.