A roadmap for therapeutic discovery in pulmonary hypertension associated with left heart failure. A scientific statement of the Heart Failure Association (HFA) of the ESC and the ESC Working Group on Pulmonary Circulation & Right Ventricular Function.

Pulmonary hypertension (PH) associated with left heart failure (LHF) (PH-LHF) is one of the most common causes of PH. It directly contributes to symptoms and reduced functional capacity and negatively affects right heart function, ultimately leading to a poor prognosis. There are no specific treatments for PH-LHF, despite the high number of drugs tested so far. This scientific document addresses the main knowledge gaps in PH-LHF with emphasis on pathophysiology and clinical trials. Key identified issues include better understanding of the role of pulmonary venous versus arteriolar remodelling, multidimensional phenotyping to recognize patient subgroups positioned to respond to different therapies, and conduct of rigorous pre-clinical studies combining small and large animal models. Advancements in these areas are expected to better inform the design of clinical trials and extend treatment options beyond those effective in pulmonary arterial hypertension. Enrichment strategies, endpoint assessments, and thorough haemodynamic studies, both at rest and during exercise, are proposed to play primary roles to optimize early-stage development of candidate therapies for PH-LHF.

Clinical implications of subclinical left ventricular dysfunction in heart failure with preserved ejection fraction: The PARAGON-HF study.

AIMS: Left ventricular (LV) subclinical impairment has been described in heart failure with preserved ejection fraction (HFpEF). We assessed the relationship between LV myocardial deformation by strain imaging and recurrent hospitalization for heart failure (HF) or cardiovascular death in a large international HFpEF population. METHODS AND RESULTS: We assessed two-dimensional speckle-tracking based global longitudinal strain (GLS) in 790 patients (mean age 74 ± 8 years, 54% female) with adequate image quality enrolled in the PARAGON-HF echocardiography study. We examined the relationship of GLS with total HF hospitalizations and cardiovascular death (the primary composite outcome) after accounting for clinical confounders. Approximately 47% of the population had evidence of LV subclinical dysfunction, defined as absolute GLS <16%. Impaired GLS was significantly associated with higher values of circulating baseline N-terminal pro-B-type-natriuretic peptide. After a median follow-up of 3.0 years, there were 407 total HF hospitalizations and cardiovascular deaths. After multivariable adjustment, worse GLS was associated with a greater risk for the primary composite outcome (adjusted hazard ratio per 1% decrease: 1.06; 95% confidence interval 1.02-1.11; p = 0.008). GLS did not modify the treatment effect of sacubitril/valsartan compared with valsartan for the composite outcome (p for interaction >0.1). CONCLUSIONS: In a large HFpEF population, impaired LV function was observed even among patients with preserved ejection fraction, and was associated with an increased risk of total HF hospitalizations or cardiovascular death, accounting for clinical confounders. These findings highlight the key role of subtle LV systolic impairment in the pathophysiology of HFpEF.

Clinical phenogroup diversity and multiplicity: impact on mechanisms of exercise intolerance in heart failure with preserved ejection fraction.

AIMS: We aimed to clarify the extent to which cardiac and peripheral impairments to oxygen delivery and utilization contribute to exercise intolerance and risk for adverse events, and how this relates to diversity and multiplicity in pathophysiologic traits. METHODS AND RESULTS: Individuals with heart failure with preserved ejection fraction (HFpEF) and non-cardiac dyspnoea (controls) underwent invasive cardiopulmonary exercise testing and clinical follow-up. Haemodynamics and oxygen transport responses were compared. HFpEF patients were then categorized a priori into previously-proposed, non-exclusive descriptive clinical trait phenogroups, including cardiometabolic, pulmonary vascular disease, left atrial myopathy, and vascular stiffening phenogroups based on clinical and haemodynamic profiles to contrast pathophysiology and clinical risk. Overall, patients with HFpEF (n = 643) had impaired cardiac output reserve with exercise (2.3 vs. 2.8 L/min, p = 0.025) and greater reliance on peripheral oxygen extraction augmentation (4.5 vs. 3.8 ml/dl, p < 0.001) compared to dyspnoeic controls (n = 219). Most (94%) patients with HFpEF met criteria for at least one clinical phenogroup, and 67% fulfilled criteria for multiple overlapping phenogroups. There was greater impairment in peripheral limitations in the cardiometabolic group and greater cardiac output limitations and higher pulmonary vascular resistance during exertion in the other phenogroups. Increasing trait multiplicity within a given patient was associated with worse exercise haemodynamics, poorer exercise capacity, lower cardiac output reserve, and greater risk for heart failure hospitalization or death (hazard ratio 1.74, 95% confidence interval 1.08-2.79 for 0-1 vs. ≥2 phenogroup traits present). CONCLUSIONS: Though cardiac output response to exercise is limited in patients with HFpEF compared to those with non-cardiac dyspnoea, the relative contributions of cardiac and peripheral limitations vary with differing numbers and types of clinical phenotypic traits present. Patients fulfilling criteria for greater multiplicity and diversity of HFpEF phenogroup traits have poorer exercise capacity, worsening haemodynamic perturbations, and greater risk for adverse outcome.

Advanced Heart Failure Characteristics and Outcomes in Commercially Insured U.S. Adults.

BACKGROUND: The characteristics and outcomes of patients with advanced heart failure (HF) have been poorly defined due to challenges in applying the complex advanced HF definition broadly to populations. OBJECTIVES: In this study, the authors sought to apply a validated advanced HF algorithm to a large U.S. administrative claims database and describe the population and use of advanced HF therapies. METHODS: This study included adults with advanced HF identified in the OptumLabs Data Warehouse from 2009 to 2019. The algorithm for advanced HF required 2 hospitalizations for HF plus 1 additional sign of advanced HF in a 12-month period. The association of baseline characteristics with mortality was examined with the use of Cox proportional hazards models. Associations of patient characteristics with advanced therapies were estimated with the use of cause-specific Cox proportional hazard models. RESULTS: In 60,197 patients identified with advanced HF, the mean age was 73 years, 51.5% were men, and 64.3% were non-Hispanic White, 1.9% Asian, 21.2% Black, and 8.2% Hispanic. The median survival with advanced HF was 2.0 years (IQR: 0.4-5.5 years). Differences in mortality and use of advanced therapies by age, sex, and race/ethnicity were observed. Adjusted mortality was higher in patients who were older, male, non-Hispanic White, and from rural areas (P < 0.05 for all). Advanced therapies were used less in older patients and women (P < 0.05 for both). Black patients were more likely to be treated with a left ventricular assist device (P = 0.010) but less likely to receive a heart transplant compared with White patients (P = 0.034). CONCLUSIONS: In U.S. adults with advanced HF, variation in outcomes and use of advanced therapies exist by age, sex, and race/ethnicity.

Interleukin-6 in Patients With Heart Failure and Preserved Ejection Fraction.

BACKGROUND: Interleukin (IL)-6 is a central inflammatory mediator and potential therapeutic target in heart failure (HF). Prior studies have shown that IL-6 concentrations are elevated in patients with HF, but much fewer data are available in heart failure with preserved ejection fraction (HFpEF). OBJECTIVES: This study aims to determine how IL-6 relates to changes in cardiac function, congestion, body composition, and exercise tolerance in HFpEF. METHODS: Clinical, laboratory, body composition, exercise capacity, physiologic and health status data across 4 National Heart, Lung, and Blood Institute-sponsored trials were analyzed according to the tertiles of IL-6. RESULTS: IL-6 was measured in 374 patients with HFpEF. Patients with highest IL-6 levels had greater body mass index; higher N-terminal pro-B-type natriuretic peptide, C-reactive protein, and tumor necrosis factor-α levels; worse renal function; and lower hemoglobin levels, and were more likely to have diabetes. Although cardiac structure and function measured at rest were similar, patients with HFpEF and highest IL-6 concentrations had more severely impaired peak oxygen consumption (12.3 ± 3.3 mL/kg/min 13.1 ± 3.1 mL/kg/min 14.4 ± 3.9 mL/kg/min, P < 0.0001) as well as 6-minute walk distance (276 ± 107 m vs 332 ± 106 m vs 352 ± 116 m, P < 0.0001), even after accounting for increases in IL-6 related to excess body mass. IL-6 concentrations were associated with increases in total body fat and trunk fat, more severe symptoms during submaximal exercise, and poorer patient-reported health status. CONCLUSIONS: IL-6 levels are commonly elevated in HFpEF, and are associated with greater symptom severity, poorer exercise capacity, and more upper body fat accumulation. These findings support testing the hypothesis that therapies that inhibit IL-6 in patients with HFpEF may improve clinical status. (Clinical Trial Registrations: Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in Diastolic Heart Failure [RELAX], NCT00763867; Nitrate's Effect on Activity Tolerance in Heart Failure With Preserved Ejection Fraction, NCT02053493; Inorganic Nitrite Delivery to Improve Exercise Capacity in HFpEF, NCT02742129; Inorganic Nitrite to Enhance Benefits From Exercise Training in Heart Failure With Preserved Ejection Fraction [HFpEF], NCT02713126).

Changes in Kidney Function After Diagnosis of Advanced Heart Failure.

BACKGROUND: Kidney function and its association with outcomes in patients with advanced heart failure (HF) has not been well-defined. METHODS AND RESULTS: We conducted a retrospective cohort study comprising all adult residents of Olmsted County, Minnesota, with HF who developed advanced HF from 2007 to 2017. Patients were grouped by estimated glomerular filtration rate (eGFR) at advanced HF diagnosis using the 2021 Chronic Kidney Disease Epidemiology Collaboration equation. A linear mixed effects model was fitted to assess the relationship between development of advanced HF and longitudinal eGFR trajectory. A total of 936 patients with advanced HF (mean age 77 years, 55% male, 93.7% White) were included. Twenty-two percent of these patients had an eGFR of <30 at advanced HF diagnosis, 22% had an eGFR of 30-44, 23% had an eGFR of 45-59, and 32% had an eGFR of ≥60 mL/min/1.73 m2. The eGFR decreased faster after advanced HF (7.6% vs 10.9% annual decline before vs after advanced HF), with greater decreases after advanced HF in those with diabetes and preserved ejection fraction. An eGFR of <30 mL/min/1.73 m2 was associated with worse survival after advanced HF compared with an eGFR of ≥60 mL/min/1.73 m2 (adjusted hazard ratio 1.30, 95% confidence interval 1.07-1.57). CONCLUSIONS: eGFR deteriorated faster after patients developed advanced HF. An eGFR of <30 mL/min/1.73 m2 at advanced HF diagnosis was associated with higher mortality.

Predicting Stroke in Heart Failure and Preserved Ejection Fraction Without Atrial Fibrillation.

BACKGROUND: The rate of stroke in patients with heart failure (HF) and preserved ejection fraction but without atrial fibrillation (AF), is uncertain as is whether it is possible to reliably predict the risk of stroke in these patients. METHODS: We validated a previously developed simple risk model for stroke among patients enrolled in the I-Preserve trial (Irbesartan in Heart Failure With Preserved Systolic Function) and PARAGON-HF trial (Efficacy and Safety of LCZ696 Compared to Valsartan, on Morbidity and Mortality in Heart Failure Patients With Preserved Ejection Fraction). The risk model consisted of 3 variables: history of previous stroke, insulin-treated diabetes, and plasma N-terminal pro-B-type natriuretic peptide level. RESULTS: Of the 8924 patients included in the pooled trial dataset, 5126 patients did not have AF at baseline. Among patients without AF, 190 (3.7%) experienced a stroke over a median follow-up of 3.6 years (rate 10.5 per 1000 patient-years). The risk for stroke increased with increasing risk score: second tertile hazard ratio, 1.78 (95% CI, 1.17-2.71); third tertile hazard ratio, 3.03 (95% CI, 2.06-4.47), with the first tertile as reference. For patients in the third tertile, the occurrence rate of stroke was 17.7 per 1000 patient-years, similar to that in patients with AF not receiving anticoagulation (20.7 per 1000 patient-years), and those with AF who were receiving anticoagulation (14.5 per 1000 patient-years). Model discrimination was good with a C index of 0.81 (0.68-0.91) and a simple score could be created from the model. CONCLUSIONS: A simple risk model can detect a subset of HF and preserved ejection fraction patients without AF who have a higher risk for stroke. The balance of risk-to-benefit in these individuals may justify the use of prophylactic anticoagulation, but this hypothesis needs to be prospectively evaluated. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifiers: NCT00095238 and NCT01920711.

How to Manage Heart Failure With Preserved Ejection Fraction: Practical Guidance for Clinicians.

Although patients with heart failure with preserved ejection fraction (HFpEF) (left ventricular ejection fraction ≥50%) comprise nearly half of those with chronic heart failure, evidence-based treatment options for this population have historically been limited. Recently, however, emerging data from prospective, randomized trials enrolling patients with HFpEF have greatly altered the range of pharmacologic options to modify disease progression in selected patients with HFpEF. In the context of this evolving landscape, clinicians are increasingly in need of practical guidance regarding the best approach to management of this growing population. In this review, the authors build on the recently published heart failure guidelines by integrating contemporary data from recent randomized trials to provide a contemporary framework for diagnosis and evidence-based treatment of patients with HFpEF. Where gaps in knowledge persist, the authors provide "best available" data from post hoc analyses of clinical trials or data from observational studies to guide management until more definitive studies are available.

Rate-Adaptive Atrial Pacing for Heart Failure With Preserved Ejection Fraction: The RAPID-HF Randomized Clinical Trial.

Importance: Reduced heart rate during exercise is common and associated with impaired aerobic capacity in heart failure with preserved ejection fraction (HFpEF), but it remains unknown if restoring exertional heart rate through atrial pacing would be beneficial. Objective: To determine if implanting and programming a pacemaker for rate-adaptive atrial pacing would improve exercise performance in patients with HFpEF and chronotropic incompetence. Design, Setting, and Participants: Single-center, double-blind, randomized, crossover trial testing the effects of rate-adaptive atrial pacing in patients with symptomatic HFpEF and chronotropic incompetence at a tertiary referral center (Mayo Clinic) in Rochester, Minnesota. Patients were recruited between 2014 and 2022 with 16-week follow-up (last date of follow-up, May 9, 2022). Cardiac output during exercise was measured by the acetylene rebreathe technique. Interventions: A total of 32 patients were recruited; of these, 29 underwent pacemaker implantation and were randomized to atrial rate responsive pacing or no pacing first for 4 weeks, followed by a 4-week washout period and then crossover for an additional 4 weeks. Main Outcomes and Measures: The primary end point was oxygen consumption (V̇o2) at anaerobic threshold (V̇o2,AT); secondary end points were peak V̇o2, ventilatory efficiency (V̇e/V̇co2 slope), patient-reported health status by the Kansas City Cardiomyopathy Questionnaire Overall Summary Score (KCCQ-OSS), and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels. Results: Of the 29 patients randomized, the mean age was 66 years (SD, 9.7) and 13 (45%) were women. In the absence of pacing, peak V̇o2 and V̇o2 at anaerobic threshold (V̇o2,AT) were both correlated with peak exercise heart rate (r = 0.46-0.51, P < .02 for both). Pacing increased heart rate during low-level and peak exercise (16/min [95% CI, 10 to 23], P < .001; 14/min [95% CI, 7 to 21], P < .001), but there was no significant change in V̇o2,AT (pacing off, 10.4 [SD, 2.9] mL/kg/min; pacing on, 10.7 [SD, 2.6] mL/kg/min; absolute difference, 0.3 [95% CI, -0.5 to 1.0] mL/kg/min; P = .46), peak V̇o2, minute ventilation (V̇e)/carbon dioxide production (V̇co2) slope, KCCQ-OSS, or NT-proBNP level. Despite the increase in heart rate, atrial pacing had no significant effect on cardiac output with exercise, owing to a decrease in stroke volume (-24 mL [95% CI, -43 to -5 mL]; P = .02). Adverse events judged to be related to the pacemaker device were observed in 6 of 29 participants (21%). Conclusions and Relevance: In patients with HFpEF and chronotropic incompetence, implantation of a pacemaker to enhance exercise heart rate did not result in an improvement in exercise capacity and was associated with increased adverse events. Trial Registration: ClinicalTrials.gov Identifier: NCT02145351.

Ventricular stiffening and chamber contracture in heart failure with higher ejection fraction.

AIMS: Ancillary analyses from clinical trials have suggested reduced efficacy for neurohormonal antagonists among patients with heart failure and preserved ejection fraction (HFpEF) and higher ranges of ejection fraction (EF). METHODS AND RESULTS: A total of 621 patients with HFpEF were grouped into those with low-normal left ventricular EF (LVEF) (HFpEF<65% , n = 319, 50% ≤ LVEF <65%) or HFpEF≥65% (n = 302, LVEF ≥65%), and compared with 149 age-matched controls undergoing comprehensive echocardiography and invasive cardiopulmonary exercise testing. A sensitivity analysis was performed in a second non-invasive community-based cohort of patients with HFpEF (n = 244) and healthy controls without cardiovascular disease (n = 617). Patients with HFpEF≥65% had smaller left ventricular (LV) end-diastolic volume than HFpEF<65% , but LV systolic function assessed by preload recruitable stroke work and stroke work/end-diastolic volume was similarly impaired. Patients with HFpEF≥65% displayed an end-diastolic pressure-volume relationship (EDPVR) that was shifted leftward, with increased LV diastolic stiffness constant ß, in both invasive and community-based cohorts. Cardiac filling pressures and pulmonary artery pressures at rest and during exercise were similarly abnormal in all EF subgroups. While patients HFpEF≥57% displayed leftward shifted EDPVR, those with HFpEF<57% had a rightward shifted EDPVR more typical of heart failure with reduced EF. CONCLUSION: Most pathophysiologic differences in patients with HFpEF and higher EF are related to smaller heart size, increased LV diastolic stiffness, and leftward shift in the EDPVR. These findings may help to explain the absence of efficacy for neurohormonal antagonists in this group and raise a new hypothesis, that interventions to stimulate eccentric LV remodelling and enhance diastolic capacitance may be beneficial for patients with HFpEF and EF in the higher range.

Heart Failure With Preserved Ejection Fraction: A Review.

Importance: Heart failure with preserved ejection fraction (HFpEF), defined as HF with an EF of 50% or higher at diagnosis, affects approximately 3 million people in the US and up to 32 million people worldwide. Patients with HFpEF are hospitalized approximately 1.4 times per year and have an annual mortality rate of approximately 15%. Observations: Risk factors for HFpEF include older age, hypertension, diabetes, dyslipidemia, and obesity. Approximately 65% of patients with HFpEF present with dyspnea and physical examination, chest radiographic, echocardiographic, or invasive hemodynamic evidence of HF with overt congestion (volume overload) at rest. Approximately 35% of patients with HFpEF present with "unexplained" dyspnea on exertion, meaning they do not have clear physical, radiographic, or echocardiographic signs of HF. These patients have elevated atrial pressures with exercise as measured with invasive hemodynamic stress testing or estimated with Doppler echocardiography stress testing. In unselected patients presenting with unexplained dyspnea, the H2FPEF score incorporating clinical (age, hypertension, obesity, atrial fibrillation status) and resting Doppler echocardiographic (estimated pulmonary artery systolic pressure or left atrial pressure) variables can assist with diagnosis (H2FPEF score range, 0-9; score >5 indicates more than 95% probability of HFpEF). Specific causes of the clinical syndrome of HF with normal EF other than HFpEF should be identified and treated, such as valvular, infiltrative, or pericardial disease. First-line pharmacologic therapy consists of sodium-glucose cotransporter type 2 inhibitors, such as dapagliflozin or empagliflozin, which reduced HF hospitalization or cardiovascular death by approximately 20% compared with placebo in randomized clinical trials. Compared with usual care, exercise training and diet-induced weight loss produced clinically meaningful increases in functional capacity and quality of life in randomized clinical trials. Diuretics (typically loop diuretics, such as furosemide or torsemide) should be prescribed to patients with overt congestion to improve symptoms. Education in HF self-care (eg, adherence to medications and dietary restrictions, monitoring of symptoms and vital signs) can help avoid HF decompensation. Conclusions and Relevance: Approximately 3 million people in the US have HFpEF. First-line therapy consists of sodium-glucose cotransporter type 2 inhibitors, exercise, HF self-care, loop diuretics as needed to maintain euvolemia, and weight loss for patients with obesity and HFpEF.

Incident Heart Failure With Mildly Reduced Ejection Fraction: Frequency, Characteristics, and Outcomes.

BACKGROUND: Heart failure (HF) with an ejection fraction (EF) of 41%-49% is recognized as HF with a mildly reduced EF (HFmrEF). However, existing knowledge of the HFmrEF phenotype is based on HF clinical trial and registry cohorts that may be limited by multiple forms of bias. METHODS AND RESULTS: In a community-based, retrospective cohort study, adult residents of Olmsted County, Minnesota, with validated (Framingham criteria) incident HF from 2007 to 2015 were categorized by echocardiographic EF at first HF diagnosis. Among 2035 adults with incident HF, 12.5% had HFmrEF, 29.9% had HF with reduced EF (HFrEF), and 57.6% had HF with preserved EF (HFpEF). Mean age and sex varied by EF group, with HFmrEF (75.6 years, 45.3% female), HFrEF (70.9 years, 36.5% female), and HFpEF (76.9 years, 59.7% female). Most comorbid conditions were more common in HFmrEF vs HFrEF, but similar in HFmrEF and HFpEF. After a mean follow-up of 4.6 ± 3.5 years, adjusting for age, sex, and comorbidities, the risks of hospitalization and cardiovascular mortality did not differ by EF category. Of patients who began as HFmrEF, 26.9% declined to an EF of 40% or less and 44.8% improved to an EF of 50% or greater. CONCLUSIONS: In this community cohort of incident HF, 12.5% have HFmrEF. Clinical characteristics in HFmrEF resemble HFpEF more than HFrEF. Adjusted hospitalization and mortality risks did not vary by EF group. Patients with incident HFmrEF usually transitioned to a different EF category on follow-up.

An intervention strategy to improve genetic testing for dilated cardiomyopathy in a heart failure clinic.

PURPOSE: Despite its clinical implications in screening and therapy, genetic testing in dilated cardiomyopathy (DCM) is underused. This study evaluated implementing a practice intervention in a heart failure clinic to automate and streamline the process of genetic testing. METHODS: Eligible patients with DCM were compared for frequency of pretest genetic education and testing during pre- and postintervention periods. The intervention comprised automated prescheduling of a cardiovascular genomics e-consult that served as a placeholder for downstream, pretest education, testing, and post-test review of genetic results. RESULTS: Patients with DCM were more likely to undergo pretest genetic education after intervention than before intervention (33.5% vs 14.8%, P < .0001). Similarly, patients with DCM were more likely to undergo genetic testing after intervention than before intervention (27.3% vs 13.0%, P = .0006). The number of patients who were diagnosed to have likely pathogenic or pathogenic genetic variants were 2 of 21 (9.5%) and 6 of 53 (11.1%) before and after intervention, respectively, and variants were present in the following genes: FLNC, TTN, DES, LMNA, PLN, and TNNT2. CONCLUSION: An intervention strategy in a heart failure clinic to increase the rates of pretest genetic education and testing in eligible patients with DCM was feasible and efficacious and may have important implications for the management of DCM.

Histologic and proteomic remodeling of the pulmonary veins and arteries in a porcine model of chronic pulmonary venous hypertension.

AIMS: In heart failure (HF), pulmonary venous hypertension (PVH) produces pulmonary hypertension (PH) with remodeling of pulmonary veins (PV) and arteries (PA). In a porcine PVH model, we performed proteomic-based bioinformatics to investigate unique pathophysiologic mechanisms mediating PA and PV remodeling. METHODS AND RESULTS: Large PV were banded (PVH, n = 10) or not (Sham, n = 9) in piglets. At sacrifice, PV and PA were perfusion labelled for vessel-specific histology and proteomics. The PA and PV were separately sampled with laser-capture micro-dissection for mass spectrometry. Pulmonary vascular resistance [Wood Units; 8.6 (95% confidence interval: 6.3, 12.3) vs. 2.0 (1.7, 2.3)] and PA [19.9 (standard error of mean, 1.1) vs. 10.3 (1.1)] and PV [14.2 (1.2) vs. 7.6 (1.1)] wall thickness/external diameter (%) were increased in PVH (P < 0.05 for all). Similar numbers of proteins were identified in PA (2093) and PV (2085) with 94% overlap, but biological processes differed. There were more differentially expressed proteins (287 vs. 161), altered canonical pathways (17 vs. 3), and predicted upstream regulators (PUSR; 22 vs. 6) in PV than PA. In PA and PV, bioinformatics indicated activation of the integrated stress response and mammalian target of rapamycin signalling with dysregulated growth. In PV, there was also activation of Rho/Rho-kinase signalling with decreased actin cytoskeletal signalling and altered tight and adherens junctions, ephrin B, and caveolae-mediated endocytosis signalling; all indicating disrupted endothelial barrier function. Indeed, protein biomarkers and the top PUSR in PV (transforming growth factor-beta) suggested endothelial to mesenchymal transition in PV. Findings were similar in human autopsy specimens. CONCLUSION: These findings provide new therapeutic targets to oppose pulmonary vascular remodeling in HF-related PH.

A Simple Score to Identify Increased Risk of Transthyretin Amyloid Cardiomyopathy in Heart Failure With Preserved Ejection Fraction.

Importance: Transthyretin amyloid cardiomyopathy (ATTR-CM) is a form of heart failure (HF) with preserved ejection fraction (HFpEF). Technetium Tc 99m pyrophosphate scintigraphy (PYP) enables ATTR-CM diagnosis. It is unclear which patients with HFpEF have sufficient risk of ATTR-CM to warrant PYP. Objective: To derive and validate a simple ATTR-CM score to predict increased risk of ATTR-CM in patients with HFpEF. Design, Setting, and Participants: Retrospective cohort study of 666 patients with HF (ejection fraction ≥ 40%) and suspected ATTR-CM referred for PYP at Mayo Clinic, Rochester, Minnesota, from May 10, 2013, through August 31, 2020. These data were analyzed September 2020 through December 2020. A logistic regression model predictive of ATTR-CM was derived and converted to a point-based ATTR-CM risk score. The score was further validated in a community ATTR-CM epidemiology study of older patients with HFpEF with increased left ventricular wall thickness ([WT] ≥ 12 mm) and in an external (Northwestern University, Chicago, Illinois) HFpEF cohort referred for PYP. Race was self-reported by the participants. In all cohorts, both case patients and control patients were definitively ascertained by PYP scanning and specialist evaluation. Main Outcomes and Measures: Performance of the derived ATTR-CM score in all cohorts (referral validation, community validation, and external validation) and prevalence of a high-risk ATTR-CM score in 4 multinational HFpEF clinical trials. Results: Participant cohorts included were referral derivation (n = 416; 13 participants [3%] were Black and 380 participants [94%] were White; ATTR-CM prevalence = 45%), referral validation (n = 250; 12 participants [5%]were Black and 228 participants [93%] were White; ATTR-CM prevalence = 48% ), community validation (n = 286; 5 participants [2%] were Black and 275 participants [96%] were White; ATTR-CM prevalence = 6% ), and external validation (n = 66; 23 participants [37%] were Black and 36 participants [58%] were White; ATTR-CM prevalence = 39%). Score variables included age, male sex, hypertension diagnosis, relative WT more than 0.57, posterior WT of 12 mm or more, and ejection fraction less than 60% (score range -1 to 10). Discrimination (area under the receiver operating characteristic curve [AUC] 0.89; 95% CI, 0.86-0.92; P < .001) and calibration (Hosmer-Lemeshow; χ2 = 4.6; P = .46) were strong. Discrimination (AUC ≥ 0.84; P < .001 for all) and calibration (Hosmer-Lemeshow χ2 = 2.8; P = .84; Hosmer-Lemeshow χ2 = 4.4; P = .35; Hosmer-Lemeshow χ2 = 2.5; P = .78 in referral, community, and external validation cohorts, respectively) were maintained in all validation cohorts. Precision-recall curves and predictive value vs prevalence plots indicated clinically useful classification performance for a score of 6 or more (positive predictive value ≥25%) in clinically relevant ATTR-CM prevalence (≥10% of patients with HFpEF) scenarios. In the HFpEF clinical trials, 11% to 35% of male and 0% to 6% of female patients had a high-risk (≥6) ATTR-CM score. Conclusions and Relevance: A simple 6 variable clinical score may be used to guide use of PYP and increase recognition of ATTR-CM among patients with HFpEF in the community. Further validation in larger and more diverse populations is needed.

Guideline-Directed Medical Therapy in Newly Diagnosed Heart Failure With Reduced Ejection Fraction in the Community.

BACKGROUND: Guideline-directed medical therapy (GDMT) dramatically improves outcomes in heart failure with reduced ejection fraction (HFrEF). Our goal was to examine GDMT use in community patients with newly diagnosed HFrEF. METHODS AND RESULTS: We performed a population-based, retrospective cohort study of all Olmsted County, Minnesota, residents with newly diagnosed HFrEF (EF ≤ 40%) 2007-2017. We excluded patients with contraindications to medication initiation. We examined the use of beta-blockers, HF beta-blockers (metoprolol succinate, carvedilol, bisoprolol), angiotensin converting enzyme inhibitors (ACEis), angiotensin receptor blockers (ARBs), angiotensin receptor neprilysin inhibitors (ARNIS), and mineralocorticoid receptor antagonists (MRAs) in the first year after HFrEF diagnosis. We used Cox models to evaluate the association of being seen in an HF clinic with the initiation of GDMT. From 2007 to 2017, 1160 patients were diagnosed with HFrEF (mean age 69.7 years, 65.6% men). Most eligible patients received beta-blockers (92.6%) and ACEis/ARBs/ARNIs (87.0%) in the first year. However, only 63.8% of patients were treated with an HF beta-blocker, and few received MRAs (17.6%). In models accounting for the role of an HF clinic in initiation of these medications, being seen in an HF clinic was independently associated with initiation of new GDMT across all medication classes, with a hazard ratio (95% CI) of 1.54 (1.15-2.06) for any beta-blocker, 2.49 (1.95-3.20) for HF beta-blockers, 1.97 (1.46-2.65) for ACEis/ARBs/ARNIs, and 2.14 (1.49-3.08) for MRAs. CONCLUSIONS: In this population-based study, most patients with newly diagnosed HFrEF received beta-blockers and ACEis/ARBs/ARNIs. GDMT use was higher in patients seen in an HF clinic, suggesting the potential benefit of referral to an HF clinic for patients with newly diagnosed HFrEF.

Pulmonary vascular disease in pulmonary hypertension due to left heart disease: pathophysiologic implications.

AIMS: Pulmonary hypertension (PH) and pulmonary vascular disease (PVD) are common and associated with adverse outcomes in left heart disease (LHD). This study sought to characterize the pathophysiology of PVD across the spectrum of PH in LHD. METHODS AND RESULTS: Patients with PH-LHD [mean pulmonary artery (PA) pressure >20 mmHg and PA wedge pressure (PAWP) ≥15 mmHg] and controls free of PH or LHD underwent invasive haemodynamic exercise testing with simultaneous echocardiography, expired air and blood gas analysis, and lung ultrasound in a prospective study. Patients with PH-LHD were divided into isolated post-capillary PH (IpcPH) and PVD [combined post- and pre-capillary PH (CpcPH)] based upon pulmonary vascular resistance (PVR <3.0 or ≥3.0 WU). As compared with controls (n = 69) and IpcPH-LHD (n = 55), participants with CpcPH-LHD (n = 40) displayed poorer left atrial function and more severe right ventricular (RV) dysfunction at rest. With exercise, patients with CpcPH-LHD displayed similar PAWP to IpcPH-LHD, but more severe RV-PA uncoupling, greater ventricular interaction, and more severe impairments in cardiac output, O2 delivery, and peak O2 consumption. Despite higher PVR, participants with CpcPH developed more severe lung congestion compared with both IpcPH-LHD and controls, which was associated lower arterial O2 tension, reduced alveolar ventilation, decreased pulmonary O2 diffusion, and greater ventilation-perfusion mismatch. CONCLUSIONS: Pulmonary vascular disease in LHD is associated with a distinct pathophysiologic signature marked by greater exercise-induced lung congestion, arterial hypoxaemia, RV-PA uncoupling, ventricular interdependence, and impairment in O2 delivery, impairing aerobic capacity. Further study is required to identify novel treatments targeting the pulmonary vasculature in PH-LHD.

Diagnosis of Heart Failure With Preserved Ejection Fraction Among Patients With Unexplained Dyspnea.

Importance: Diagnosis of heart failure with preserved ejection fraction (HFpEF) among dyspneic patients without overt congestion is challenging. Multiple diagnostic approaches have been proposed but are not well validated against the independent gold standard for HFpEF diagnosis of an elevated pulmonary capillary wedge pressure (PCWP) during exercise. Objective: To evaluate H2FPEF and HFA-PEFF scores and a PCWP/cardiac output (CO) slope of more than 2 mm Hg/L/min to diagnose HFpEF. Design, Setting, and Participants: This retrospective case-control study included patients with unexplained dyspnea from 6 centers in the US, the Netherlands, Denmark, and Australia from March 2016 to October 2020. Diagnosis of HFpEF (cases) was definitively ascertained by the presence of elevated PCWP during exertion; control individuals were those with normal rest and exercise hemodynamics. Main Outcomes and Measures: Logistic regression was used to evaluate the accuracy of HFA-PEFF and H2FPEF scores to discriminate patients with HFpEF from controls. Results: Among 736 patients, 563 (76%) were diagnosed with HFpEF (mean [SD] age, 69 [11] years; 334 [59%] female) and 173 (24%) represented controls (mean [SD] age, 60 [15] years; 109 [63%] female). H2FPEF and HFA-PEFF scores discriminated patients with HFpEF from controls, but the H2FPEF score had greater area under the curve (0.845; 95% CI, 0.810-0.875) compared with the HFA-PEFF score (0.710; 95% CI, 0.659-0.756) (difference, -0.134; 95% CI, -0.177 to -0.094; P < .001). Specificity was robust for both scores, but sensitivity was poorer for HFA-PEFF, with a false-negative rate of 55% for low-probability scores compared with 25% using the H2FPEF score. Use of the PCWP/CO slope to redefine HFpEF rather than exercise PCWP reclassified 20% (117 of 583) of patients, but patients reclassified from HFpEF to control by this metric had clinical, echocardiographic, and hemodynamic features typical of HFpEF, including elevated resting PCWP in 66% (46 of 70) of reclassified patients. Conclusions and Relevance: In this case-control study, despite requiring fewer data, the H2FPEF score had superior diagnostic performance compared with the HFA-PEFF score and PCWP/CO slope in the evaluation of unexplained dyspnea and HFpEF in the outpatient setting.