Cardiovascular Effects of Oral Ketone Ester Treatment in Patients With Heart Failure With Reduced Ejection Fraction: A Randomized, Controlled, Double-Blind Trial

BACKGROUND

Heart failure triggers a shift in myocardial metabolic substrate utilization, favoring the ketone body 3-hydroxybutyrate as energy source. We hypothesized that 14-day treatment with ketone ester (KE) would improve resting and exercise hemodynamics and exercise capacity in patients with heart failure with reduced ejection fraction.

METHODS

In a randomized, double-blind cross-over study, nondiabetic patients with heart failure with reduced ejection fraction received 14-day KE and 14-day isocaloric non-KE comparator regimens of 4 daily doses separated by a 14-day washout period. After each treatment period, participants underwent right heart catheterization, echocardiography, and blood sampling at plasma trough levels and after dosing. Participants underwent an exercise hemodynamic assessment after a second dosing. The primary end point was resting cardiac output (CO). Secondary end points included resting and exercise pulmonary capillary wedge pressure and peak exercise CO and metabolic equivalents.

RESULTS

We included 24 patients with heart failure with reduced ejection fraction (17 men; 65±9 years of age; all White). Resting CO at trough levels was higher after KE compared with isocaloric comparator (5.2±1.1 L/min versus 5.0±1.1 L/min; difference, 0.3 L/min [95% CI, 0.1-0.5), and pulmonary capillary wedge pressure was lower (8±3 mm Hg versus 11±3 mm Hg; difference, -2 mm Hg [95% CI, -4 to -1]). These changes were amplified after KE dosing. Across all exercise intensities, KE treatment was associated with lower mean exercise pulmonary capillary wedge pressure (-3 mm Hg [95% CI, -5 to -1] ) and higher mean CO (0.5 L/min [95% CI, 0.1-0.8]), significantly different at low to moderate steady-state exercise but not at peak. Metabolic equivalents remained similar between treatments. In exploratory analyses, KE treatment was associated with 18% lower NT-proBNP (N-terminal pro-B-type natriuretic peptide; difference, -98 ng/L [95% CI, -185 to -23]), higher left ventricular ejection fraction (37±5 versus 34±5%; P=0.01), and lower left atrial and ventricular volumes.

CONCLUSIONS

KE treatment for 14 days was associated with higher CO at rest and lower filling pressures, cardiac volumes, and NT-proBNP levels compared with isocaloric comparator. These changes persisted during exercise and were achieved on top of optimal medical therapy. Sustained modulation of circulating ketone bodies is a potential treatment principle in patients with heart failure with reduced ejection fraction.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT05161650.

Semaglutide versus placebo in people with obesity-related heart failure with preserved ejection fraction: a pooled analysis of the STEP-HFpEF and STEP-HFpEF DM randomised trials

BACKGROUND

In the STEP-HFpEF (NCT04788511) and STEP-HFpEF DM (NCT04916470) trials, the GLP-1 receptor agonist semaglutide improved symptoms, physical limitations, bodyweight, and exercise function in people with obesity-related heart failure with preserved ejection fraction. In this prespecified pooled analysis of the STEP-HFpEF and STEP-HFpEF DM trials, we aimed to provide a more definitive assessment of the effects of semaglutide across a range of outcomes and to test whether these effects were consistent across key patient subgroups.

METHODS

We conducted a prespecified pooled analysis of individual patient data from STEP-HFpEF and STEP-HFpEF DM, randomised, double-blind, placebo-controlled trials at 129 clinical research sites in 18 countries. In both trials, eligible participants were aged 18 years or older, had heart failure with a left ventricular ejection fraction of at least 45%, a BMI of at least 30 kg/m2, New York Heart Association class II-IV symptoms, and a Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS; a measure of heart failure-related symptoms and physical limitations) of less than 90 points. In STEP-HFpEF, people with diabetes or glycated haemoglobin A1c concentrations of at least 6·5% were excluded, whereas for inclusion in STEP-HFpEF DM participants had to have been diagnosed with type 2 diabetes at least 90 days before screening and to have an HbA1c of 10% or lower. In both trials, participants were randomly assigned to either 2·4 mg semaglutide once weekly or matched placebo for 52 weeks. The dual primary endpoints were change from baseline to week 52 in KCCQ-CSS and bodyweight in all randomly assigned participants. Confirmatory secondary endpoints included change from baseline to week 52 in 6-min walk distance, a hierarchical composite endpoint (all-cause death, heart failure events, and differences in changes in KCCQ-CSS and 6-min walk distance); and C-reactive protein (CRP) concentrations. Heterogeneity in treatment effects was assessed across subgroups of interest. We assessed safety in all participants who received at least one dose of study drug.

FINDINGS

Between March 19, 2021 and March 9, 2022, 529 people were randomly assigned in STEP-HFpEF, and between June 27, 2021 and Sept 2, 2022, 616 were randomly assigned in STEP-HFpEF DM. Overall, 1145 were included in our pooled analysis, 573 in the semaglutide group and 572 in the placebo group. Improvements in KCCQ-CSS and reductions in bodyweight between baseline and week 52 were significantly greater in the semaglutide group than in the placebo group (mean between-group difference for the change from baseline to week 52 in KCCQ-CSS 7·5 points [95% CI 5·3 to 9·8]; p<0·0001; mean between-group difference in bodyweight at week 52 -8·4% [-9·2 to -7·5]; p<0·0001). For the confirmatory secondary endpoints, 6-min walk distance (mean between-group difference at week 52 17·1 metres [9·2 to 25·0]) and the hierarchical composite endpoint (win ratio 1·65 [1·42 to 1·91]) were significantly improved, and CRP concentrations (treatment ratio 0·64 [0·56 to 0·72]) were significantly reduced, in the semaglutide group compared with the placebo group (p<0·0001 for all comparisons). For the dual primary endpoints, the efficacy of semaglutide was largely consistent across multiple subgroups, including those defined by age, race, sex, BMI, systolic blood pressure, baseline CRP, and left ventricular ejection fraction. 161 serious adverse events were reported in the semaglutide group compared with 301 in the placebo group.

INTERPRETATION

In this prespecified pooled analysis of the STEP-HFpEF and STEP-HFpEF DM trials, semaglutide was superior to placebo in improving heart failure-related symptoms and physical limitations, and reducing bodyweight in participants with obesity-related heart failure with preserved ejection fraction. These effects were largely consistent across patient demographic and clinical characteristics. Semaglutide was well tolerated.

FUNDING

Novo Nordisk.

The Natural History of Atrial Functional Mitral Regurgitation

BACKGROUND

The natural history of moderate/severe atrial functional mitral regurgitation (AFMR) is unknown.

OBJECTIVES

The authors sought to study the incidence of left ventricular (LV) systolic dysfunction (LVSD), progression or regression of ≥mild-moderate AFMR, and impact on mortality.

METHODS

Adults with left atrial (LA) volume index ≥40 mL/m2, ≥mild-moderate AFMR, and follow-up echocardiogram were followed for incident LVSD (ejection fraction <50% and ≥10% lower than baseline), progression of mild-moderate/moderate AFMR to severe, and persistent regression of AFMR to no/trivial. Relation of AFMR progression or regression as time-dependent covariates with all-cause mortality was studied. Incidence of LVSD was compared with patients with no/mild AFMR matched on age, sex, comorbidities and ejection fraction. Patients were followed until mitral intervention, myocardial infarction, or last follow-up.

RESULTS

A total of 635 patients (median age 75 years, 51% female, 96% mild-moderate/moderate AFMR, 4% severe AFMR) were included. Over a median 2.2 years (Q1-Q3: 1.0-4.3 years), incidence rates per 100 person-years were 3.2 for LVSD (P = 0.52 vs patients with no/mild AFMR), 1.9 for progression of AFMR, and 3.9 for regression. Female sex and larger LA volume index were independently associated with progression, whereas younger age, male sex, absent atrial fibrillation, and higher LA emptying fraction were independently associated with regression. Neither AFMR progression nor regression was independently associated with mortality. Instead, independent risk factors for mortality included older age, concentric LV geometry, and higher estimated LV filling and pulmonary pressures.

CONCLUSIONS

In patients with predominantly mild-moderate/moderate AFMR, regression of MR was more common than progression, but neither was associated with mortality. Instead, diastolic function abnormalities were more important. Over a median 2-year follow-up, LVSD risk was not increased.

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.

Semaglutide in Patients with Obesity-Related Heart Failure and Type 2 Diabetes

BACKGROUND

Obesity and type 2 diabetes are prevalent in patients with heart failure with preserved ejection fraction and are characterized by a high symptom burden. No approved therapies specifically target obesity-related heart failure with preserved ejection fraction in persons with type 2 diabetes.

METHODS

We randomly assigned patients who had heart failure with preserved ejection fraction, a body-mass index (the weight in kilograms divided by the square of the height in meters) of 30 or more, and type 2 diabetes to receive once-weekly semaglutide (2.4 mg) or placebo for 52 weeks. The primary end points were the change from baseline in the Kansas City Cardiomyopathy Questionnaire clinical summary score (KCCQ-CSS; scores range from 0 to 100, with higher scores indicating fewer symptoms and physical limitations) and the change in body weight. Confirmatory secondary end points included the change in 6-minute walk distance; a hierarchical composite end point that included death, heart failure events, and differences in the change in the KCCQ-CSS and 6-minute walk distance; and the change in the C-reactive protein (CRP) level.

RESULTS

A total of 616 participants underwent randomization. The mean change in the KCCQ-CSS was 13.7 points with semaglutide and 6.4 points with placebo (estimated difference, 7.3 points; 95% confidence interval [CI], 4.1 to 10.4; P<0.001), and the mean percentage change in body weight was -9.8% with semaglutide and -3.4% with placebo (estimated difference, -6.4 percentage points; 95% CI, -7.6 to -5.2; P<0.001). The results for the confirmatory secondary end points favored semaglutide over placebo (estimated between-group difference in change in 6-minute walk distance, 14.3 m [95% CI, 3.7 to 24.9; P = 0.008]; win ratio for hierarchical composite end point, 1.58 [95% CI, 1.29 to 1.94; P<0.001]; and estimated treatment ratio for change in CRP level, 0.67 [95% CI, 0.55 to 0.80; P<0.001]). Serious adverse events were reported in 55 participants (17.7%) in the semaglutide group and 88 (28.8%) in the placebo group.

CONCLUSIONS

Among patients with obesity-related heart failure with preserved ejection fraction and type 2 diabetes, semaglutide led to larger reductions in heart failure-related symptoms and physical limitations and greater weight loss than placebo at 1 year. (Funded by Novo Nordisk; STEP-HFpEF DM ClinicalTrials.gov number, NCT04916470.).

Atrial Shunt Device Effects on Cardiac Structure and Function in Heart Failure With Preserved Ejection Fraction: The REDUCE LAP-HF II Randomized Clinical Trial

Importance

Although the results of A Study to Evaluate the Corvia Medical Inc IASD System II to Reduce Elevated Left Atrial Pressure in Patients with Heart Failure (REDUCE LAP-HF II) trial were neutral overall, atrial shunt therapy demonstrated potential efficacy in responders (no latent pulmonary vascular disease and no cardiac rhythm management device). Post hoc analyses were conducted to evaluate the effect of shunt vs sham stratified by responder status.

Objective

To evaluate the effect of atrial shunt vs sham control on cardiac structure/function in the overall study and stratified by responder status.

Design, Setting, and Participants

This was a sham-controlled randomized clinical trial of an atrial shunt device in heart failure with preserved ejection fraction (HFpEF)/HF with mildly reduced EF (HFmrEF). Trial participants with evaluable echocardiography scans were recruited from 89 international medical centers. Data were analyzed from April 2023 to January 2024.

Interventions

Atrial shunt device or sham control.

Main Outcome Measures

Changes in echocardiographic measures from baseline to 1, 6, 12, and 24 months after index procedure.

Results

The modified intention-to-treat analysis of the REDUCE LAP-HF II trial included 621 randomized patients (median [IQR] age, 72.0 [66.0-77.0] years; 382 female [61.5%]; shunt arm, 309 [49.8%]; sham control arm, 312 [50.2%]). Through 24 months, 212 of 217 patients (98%) in the shunt arm with evaluable echocardiograms had patent shunts. In the overall trial population, the shunt reduced left ventricular (LV) end-diastolic volume (mean difference, -5.65 mL; P <.001), left atrial (LA) minimal volume (mean difference, -2.8 mL; P =.01), and improved LV systolic tissue Doppler velocity (mean difference, 0.69 cm/s; P <.001) and LA emptying fraction (mean difference, 1.88 percentage units; P =.02) compared with sham. Shunt treatment also increased right ventricular (RV; mean difference, 9.58 mL; P <.001) and right atrial (RA; mean difference, 9.71 mL; P <.001) volumes but had no effect on RV systolic function, pulmonary artery pressure, or RA pressure compared with sham. In the shunt arm, responders had smaller increases in RV end-diastolic volume (mean difference, 5.71 mL vs 15.18 mL; interaction P =.01), RV end-systolic volume (mean difference, 1.58 mL vs 7.89 mL; interaction P =.002), and RV/LV ratio (mean difference, 0.07 vs 0.20; interaction P <.001) and larger increases in transmitral A wave velocity (mean difference, 5.08 cm/s vs -1.97 cm/s; interaction P =.02) compared with nonresponders randomized to the shunt, suggesting greater ability to accommodate shunted blood through the pulmonary circulation enabling LA unloading.

Conclusions and Relevance

In this post hoc analysis of the REDUCE LAP-HF II trial, over 2 years of follow-up, atrial shunting led to reverse remodeling of left-sided chambers and increases in volume of right-sided chambers consistent with the shunt flow but no change in RV systolic function compared with sham. Changes in cardiac structure/function were more favorable in responders compared with nonresponders treated with the shunt, supporting the previously identified responder group hypothesis and mechanism, although further evaluation with longer follow-up is needed.

Trial Registration

ClinicalTrials.gov Identifier: NCT03088033.

Targeted Metabolomic Profiling of Dapagliflozin in Heart Failure With Preserved Ejection Fraction: The PRESERVED-HF Trial

BACKGROUND

Although sodium glucose co-transporter 2 inhibitors (SGLT2is) improve heart failure (HF)-related symptoms and outcomes in HF with preserved ejection fraction (HFpEF), underlying mechanisms remain unclear. In HF with reduced EF, dapagliflozin altered ketone and fatty acid metabolites vs placebo; however, metabolite signatures of SGLT2is have not been well elucidated in HFpEF.

OBJECTIVES

The goal of this study was to assess whether SGLT2i treatment altered systemic metabolic pathways and their relationship to outcomes in HFpEF.

METHODS

Targeted profiling of 64 metabolites was performed from 293 participants in PRESERVED-HF (Dapagliflozin in PRESERVED Ejection Fraction Heart Failure), a 12-week, placebo-controlled trial of dapagliflozin. Linear regression assessed changes in metabolite factors defined by principal components analysis (PCA) with dapagliflozin vs placebo. The relationship between changes in metabolite factors with changes in study endpoints was also assessed.

RESULTS

The mean age was 70 ± 11 years, 58% were female, and 29% were Black. There were no significant differences in 12 PCA-derived metabolite factors between treatment arms, including metabolites reflecting ketone, fatty acid, or branched-chain amino acid (BCAA) pathways. Combining treatment arms, changes in BCAAs and branched-chain ketoacids were negatively associated with changes in N-terminal pro-B-type natriuretic peptide; changes in medium-/long-chain acylcarnitines were positively associated with changes in N-terminal pro-B-type natriuretic peptide and negatively associated with changes in 6-minute walk test distance; and changes in ketones were negatively associated with changes in weight, without treatment interaction.

CONCLUSIONS

Leveraging targeted metabolomics in a placebo-controlled SGLT2i trial of HFpEF, dapagliflozin did not alter systemic metabolic as reflected by circulating metabolites, in contrast with reported effects in HF with reduced ejection fraction. Metabolite biomarkers reflecting BCAA, ketone, and fatty acid metabolism were associated with markers of disease severity, suggesting a role for potential novel treatment targets. (Dapagliflozin in PRESERVED Ejection Fraction Heart Failure [PRESERVED-HF]; NCT03030235).

Pressure overload is associated with right ventricular dyssynchrony in heart failure with reduced ejection fraction

AIMS

The determinants and relevance of right ventricular (RV) mechanical dyssynchrony in heart failure with reduced ejection fraction (HFrEF) are poorly understood. We hypothesized that increased afterload may adversely affect the synchrony of RV contraction.

METHODS AND RESULTS

A total of 148 patients with HFrEF and 36 controls underwent echocardiography, right heart catheterization, and gated single-photon emission computed tomography to measure RV chamber volumes and mechanical dyssynchrony (phase standard deviation of systolic displacement timing). Exams were repeated after preload (N = 135) and afterload (N = 15) modulation. Patients with HFrEF showed higher RV dyssynchrony compared with controls (40.6 ± 17.5° vs. 27.8 ± 9.1°, P < 0.001). The magnitude of RV dyssynchrony in HFrEF correlated with larger RV and left ventricular (LV) volumes, lower RV ejection fraction (RVEF) and LV ejection fraction, reduced intrinsic contractility, increased heart rate, higher pulmonary artery (PA) load, and impaired RV-PA coupling (all P ≤ 0.01). Low RVEF was the strongest predictor of RV dyssynchrony. Left bundle branch block (BBB) was associated with greater RV dyssynchrony than right BBB, regardless of QRS duration. RV afterload reduction by sildenafil improved RV dyssynchrony (P = 0.004), whereas preload change with passive leg raise had modest effect. Patients in the highest tertiles of RV dyssynchrony had an increased risk of adverse clinical events compared with those in the lower tertile [T2/T3 vs. T1: hazard ratio 1.98 (95% confidence interval 1.20-3.24), P = 0.007].

CONCLUSIONS

RV dyssynchrony is associated with RV remodelling, dysfunction, adverse haemodynamics, and greater risk for adverse clinical events. RV dyssynchrony is mitigated by acute RV afterload reduction and could be a potential therapeutic target to improve RV performance in HFrEF.

Cardiac dysfunction rather than aortic valve stenosis severity drives exercise intolerance and adverse haemodynamics

AIMS

To study the impact of heart failure with preserved ejection fraction (HFpEF) vs. aortic stenosis (AS) lesion severity on left ventricular (LV) hypertrophy, diastolic dysfunction, left atrial (LA) dysfunction, haemodynamics, and exercise capacity.

METHODS AND RESULTS

Patients (n = 206) with at least moderate AS (aortic valve area ≤0.85 cm/m2) and discordant symptoms underwent cardiopulmonary exercise testing with simultaneous echocardiography. The population was stratified according to the probability of underlying HFpEF by the heavy, hypertension, atrial fibrillation, pulmonary hypertension, elder, filling pressure (H2FPEF) score [0-5 (AS/HFpEF-) vs. 6-9 points (AS/HFpEF+)] and AS severity (Moderate vs. Severe). Mean age was 73 ± 10 years with 40% women. Twenty-eight patients had Severe AS/HFpEF+ (14%), 111 Severe AS/HFpEF- (54%), 13 Moderate AS/HFpEF+ (6%), and 54 Moderate AS/HFpEF- (26%). AS/HFpEF+ vs. AS/HFpEF- patients, irrespective of AS severity, had a lower LV global longitudinal strain, impaired diastolic function, reduced LV compliance, and more pronounced LA dysfunction. The pulmonary arterial pressure-cardiac output slope was significantly higher in AS/HFpEF+ vs. AS/HFpEF- (5.4 ± 3.1 vs. 3.9 ± 2.2 mmHg/L/min, respectively; P = 0.003), mainly driven by impaired cardiac output and chronotropic reserve, with signs of right ventricular pulmonary arterial uncoupling. AS/HFpEF+ vs. AS/HFpEF- was associated with a lower peak aerobic capacity (11.5 ± 3.7 vs. 15.9 ± 5.9 mL/min/kg, respectively; P < 0.0001) but did not differ between Moderate and Severe AS (14.7 ± 5.5 vs. 15.2 ± 5.9 mL/min/kg, respectively; P = 0.6).

CONCLUSION

A high H2FPEF score is associated with a reduced exercise capacity and adverse haemodynamics in patients with moderate to severe AS. Both exercise performance and haemodynamics correspond better with intrinsic cardiac dysfunction than AS severity.

Biatrial myopathy in heart failure with preserved ejection fraction

AIM

Left atrial (LA) myopathy is increasingly recognized as an important phenotypic trait in heart failure (HF) with preserved ejection fraction (HFpEF). Right atrial (RA) remodelling and dysfunction also develop in HFpEF, but little data are available regarding the clinical characteristics and pathophysiology among patients with isolated LA, RA, or biatrial myopathy.

METHODS AND RESULTS

Patients with HFpEF underwent invasive haemodynamic exercise testing, comprehensive imaging including speckle tracking strain echocardiography, and clinical follow-up at Mayo Clinic between 2006 and 2018. LA myopathy was defined as LA volume index >34 ml/m2 and/or LA reservoir strain ≤24% and RA myopathy by RA volume index >39 ml/m2 in men and >33 ml/m2 in women and/or RA reservoir strain ≤19.8%. Of 476 consecutively evaluated patients with HFpEF defined by invasive exercise testing with evaluable atrial structure/function, 125 (26%) had no atrial myopathy, 147 (31%) had isolated LA myopathy, 184 (39%) had biatrial myopathy, and 20 (4%) had isolated RA myopathy. Patients with HFpEF and biatrial myopathy had more atrial fibrillation, poorer left ventricular systolic and diastolic function, more severe pulmonary vascular disease, tricuspid regurgitation, ventricular interdependence and right ventricular dysfunction, and poorer cardiac output reserve with exercise. There were 94 patients with events over a median follow-up of 2.9 (interquartile range 1.4-4.6) years. Individuals with biatrial myopathy had an 84% higher risk of HF hospitalization or death as compared to those with isolated LA myopathy (hazard ratio 1.84; 95% confidence interval 1.16-2.92, p = 0.01).

CONCLUSIONS

Biatrial myopathy identifies patients with more advanced HFpEF characterized by more severe pulmonary vascular disease, right HF, poorer cardiac reserve, and a greater risk for adverse outcomes. Further study is required to define optimal strategies to treat and prevent biatrial myopathy in HFpEF.

Inorganic Nitrite to Amplify the Benefits and Tolerability of Exercise Training in Heart Failure With Preserved Ejection Fraction: The INABLE-Training Trial

OBJECTIVE

To determine whether nitrite can enhance exercise training (ET) effects in heart failure with preserved ejection fraction (HFpEF).

METHODS

In this multicenter, double-blind, placebo-controlled, randomized trial conducted at 1 urban and 9 rural outreach centers between November 22, 2016, and December 9, 2021, patients with HFpEF underwent ET along with inorganic nitrite 40 mg or placebo 3 times daily. The primary end point was peak oxygen consumption (VO2). Secondary end points included Kansas City Cardiomyopathy Questionnaire overall summary score (KCCQ-OSS, range 0 to 100; higher scores reflect better health status), 6-minute walk distance, and actigraphy.

RESULTS

Of 92 patients randomized, 73 completed the trial because of protocol modifications necessitated by loss of drug availability. Most patients were older than 65 years (80%), were obese (75%), and lived in rural settings (63%). At baseline, median peak VO2 (14.1 mL·kg-1·min-1) and KCCQ-OSS (63.7) were severely reduced. Exercise training improved peak VO2 (+0.8 mL·kg-1·min-1; 95% CI, 0.3 to 1.2; P<.001) and KCCQ-OSS (+5.5; 95% CI, 2.5 to 8.6; P<.001). Nitrite was well tolerated, but treatment with nitrite did not affect the change in peak VO2 with ET (nitrite effect, -0.13; 95% CI, -1.03 to 0.76; P=.77) or KCCQ-OSS (-1.2; 95% CI, -7.2 to 4.9; P=.71). This pattern was consistent across other secondary outcomes.

CONCLUSION

For patients with HFpEF, ET administered for 12 weeks in a predominantly rural setting improved exercise capacity and health status, but compared with placebo, treatment with inorganic nitrite did not enhance the benefit from ET.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02713126.

Exercise catheterization in adults post-Fontan with normal and abnormal haemodynamic criteria: Insights into normal Fontan physiology

AIM

The normal (i.e. expected) haemodynamics in adults post-Fontan remain poorly delineated. Moreover, the definitions of elevated exercise pulmonary artery (PA) and PA wedge pressure (PAWP) for this population have not been described.

METHODS AND RESULTS

Seventy-two adults post-Fontan undergoing exercise catheterization were categorized into abnormal (Group I, n = 59; defined as resting mean PA ≥14 mmHg and/or PAWP ≥12 mmHg, ΔPAWP/Δsystemic flow [Qs] >2 mmHg/L/min, and/or ΔPA/Δpulmonary flow >3 mmHg/L/min) and normal (Group II, n = 13) haemodynamics. Thirty-nine patients with non-cardiac dyspnoea (NCD) were included as controls. There was no difference in exercise arterial oxygen saturation (87% [81-92] vs. 89% [85-93], p = 0.29), while exercise PA pressure (27 [23-31] vs. 16 [14.5-19.5] mmHg, p < 0.001) and PAWP were higher (21 [18-28] vs. 12 [8-14] mmHg, p < 0.001) in Group I. At peak exercise, Group I had lower heart rate (97 [81-120] vs. 133 [112.5-147.5] bpm, p < 0.001) and Qs response (67.3 [43.8-93.1] vs. 105.9 (82-118.5) % predicted, p < 0.001) than Group II. Exercise superior vena cava pressures were higher (16 [14-22.5] vs. 5.5 [3-7.3] mmHg, p < 0.001) and arterial oxygen saturation lower (89% [85-93] vs. 97% [96-98], p < 0.001) in Group II compared to NCD, while no differences in PAWP, stroke volume index, heart rate, or Qs response were seen. If defined as two standard deviations above mean values for Group II, elevated PAWP and mean PA pressure post-Fontan would correspond to 20.6 mmHg and 25.8 mmHg, respectively.

CONCLUSION

PAWP >20 mmHg and mean PA pressure >25 mmHg could be used to define elevated values during exercise in adults post-Fontan. The major discrepancy in exercise haemodynamics among Group II compared to controls appears to be the degree of systemic venous hypertension and arterial desaturation.

The effect of bariatric surgery type on cardiac reverse remodelling

INTRODUCTION

Bariatric surgery is effective in reversing adverse cardiac remodelling in obesity. However, it is unclear whether the three commonly performed operations; Roux-en-Y Gastric Bypass (RYGB), Laparoscopic Sleeve Gastrectomy (LSG) and Laparoscopic Adjustable Gastric Band (LAGB) are equal in their ability to reverse remodelling.

METHODS

Fifty-eight patients underwent CMR to assess left ventricular mass (LVM), LV mass:volume ratio (LVMVR) and LV eccentricity index (LVei) before and after bariatric surgery (26 RYGB, 22 LSG and 10 LAGB), including 46 with short-term (median 251-273 days) and 43 with longer-term (median 983-1027 days) follow-up. Abdominal visceral adipose tissue (VAT) and epicardial adipose tissue (EAT) were also assessed.

RESULTS

All three procedures resulted in significant decreases in excess body weight (48-70%). Percentage change in VAT and EAT was significantly greater following RYGB and LSG compared to LAGB at both timepoints (VAT:RYGB -47% and -57%, LSG -47% and -54%, LAGB -31% and -25%; EAT:RYGB -13% and -14%, LSG -16% and -19%, LAGB -5% and -5%). Patients undergoing LAGB, whilst having reduced LVM (-1% and -4%), had a smaller decrease at both short (RYGB: -8%, p < 0.005; LSG: -11%, p < 0.0001) and long (RYGB: -12%, p = 0.009; LSG: -13%, p < 0.0001) term timepoints. There was a significant decrease in LVMVR at the long-term timepoint following both RYGB (-7%, p = 0.006) and LSG (-7%, p = 0.021), but not LAGB (-2%, p = 0.912). LVei appeared to decrease at the long-term timepoint in those undergoing RYGB (-3%, p = 0.063) and LSG (-4%, p = 0.015), but not in those undergoing LAGB (1%, p = 0.857). In all patients, the change in LVM correlated with change in VAT (r = 0.338, p = 0.0134), while the change in LVei correlated with change in EAT (r = 0.437, p = 0.001).

CONCLUSIONS

RYGB and LSG appear to result in greater decreases in visceral adiposity, and greater reverse LV remodelling with larger reductions in LVM, concentric remodelling and pericardial restraint than LAGB.

Determinants and prognostic implications of left atrial reverse remodelling after coarctation of aorta repair in adults

AIMS

Left atrial (LA) dysfunction and atrial fibrillation are also relatively common in adults with coarctation of aorta (COA), and the severity of LA dysfunction is associated with a higher risk of atrial fibrillation in this population. The purpose of this study was to determine whether LA function improved after COA repair (LA reverse remodelling), and the relationship between LA reverse remodelling and atrial fibrillation.

METHODS AND RESULTS

Retrospective cohort study of adults undergoing COA repair (2003-20). LA reservoir strain was assessed pre intervention and 12-24 months post intervention, using speckle tracking echocardiography. Incident atrial fibrillation was assessed from COA repair to last follow-up. Of 261 adults who underwent COA repair [age 37 ± 13 years; males 148 (57%)], 124 (47%) and 137 (53%) presented with native vs. recurrent COA, respectively. Of 261 patients, 231 (82%) and 48 (18%) underwent surgical and transcatheter COA repair, respectively. The LA reservoir strain increased from 32 ± 8% (pre intervention) to 39 ± 7% (post intervention), yielding a relative increase of 21 ± 5%. Older age [β ± standard error (SE) -0.16 ± 0.09 per 5 years, P = 0.02], higher systolic blood pressure (β ± SE -0.12 ± 0.04 per 5 mmHg, P = 0.005), and higher residual COA mean gradient (β ± SE -0.17 ± 0.06 per 5 mmHg, P = 0.002) post intervention were associated with less LA reverse remodelling, after adjustment for sex, hypertension diagnosis, and left ventricular indices. LA reverse remodelling (hazard ratio 0.97, 95% confidence interval 0.96-0.98 per 1% increase from pre-intervention LA function, P = 0.006) was associated with a lower risk of atrial fibrillation after adjustment for age, sex, pre-intervention LA reservoir strain, and history of atrial fibrillation.

CONCLUSION

COA repair resulted in improved LA function and decreased risk for atrial fibrillation, especially in patients without residual hypertension or significant residual COA gradient.

Effects of Semaglutide on Symptoms, Function, and Quality of Life in Patients With Heart Failure With Preserved Ejection Fraction and Obesity: A Prespecified Analysis of the STEP-HFpEF Trial

BACKGROUND

Patients with heart failure (HF) with preserved ejection fraction (HFpEF) and obesity experience a high burden of symptoms and functional impairment, and a poor quality of life. In the STEP-HFpEF trial (Research Study to Investigate How Well Semaglutide Works in People Living With Heart Failure and Obesity), once-weekly semaglutide 2.4 mg improved symptoms, physical limitations, and exercise function, and reduced inflammation and body weight. This prespecified analysis investigated the effects of semaglutide on the primary and confirmatory secondary end points across the range of the Kansas City Cardiomyopathy Questionnaire (KCCQ) scores at baseline and on all key summary and individual KCCQ domains.

METHODS

STEP-HFpEF randomly assigned 529 participants with symptomatic HF, an ejection fraction of ≥45%, and a body mass index of ≥30 kg/m2 to once-weekly semaglutide 2.4 mg or placebo for 52 weeks. Dual primary end points change in KCCQ-Clinical Summary Score (CSS) and body weight. Confirmatory secondary end points included change in 6-minute walk distance, a hierarchical composite end point (death, HF events, and change in KCCQ-CSS and 6-minute walk distance) and change in C-reactive protein. Patients were stratified by KCCQ-CSS tertiles at baseline. Semaglutide effects on the primary, confirmatory secondary, and select exploratory end points (N-terminal pro-brain natriuretic peptide) were examined across these subgroups. Semaglutide effects on additional KCCQ domains (Total Symptom Score [including symptom burden and frequency], Physical Limitations Score, Social Limitations Score, Quality of Life Score, and Overall Summary Score) were also evaluated.

RESULTS

Baseline median KCCQ-CSS across tertiles was 37, 59, and 77 points, respectively. Semaglutide consistently improved primary end points across KCCQ tertiles 1 to 3 (estimated treatment differences [95% CI]: for KCCQ-CSS, 10.7 [5.4 to 16.1], 8.1 [2.7 to 13.4], and 4.6 [-0.6 to 9.9] points; for body weight, -11 [-13.2 to -8.8], -9.4 [-11.5 to -7.2], and -11.8 [-14.0 to -9.6], respectively; Pinteraction=0.28 and 0.29, respectively); the same was observed for confirmatory secondary and exploratory end points (Pinteraction>0.1 for all). Semaglutide-treated patients experienced improvements in all key KCCQ domains (estimated treatment differences, 6.7-9.6 points across domains; P≤0.001 for all). Greater proportion of semaglutide-treated versus placebo-treated patients experienced at least 5-, 10-, 15-, and 20-point improvements in all KCCQ domains (odds ratios, 1.6-2.9 across domains; P<0.05 for all).

CONCLUSIONS

In patients with HFpEF and obesity, semaglutide produced large improvements in HF-related symptoms, physical limitations, exercise function, inflammation, body weight, and N-terminal pro-brain natriuretic peptide, regardless of baseline health status. The benefits of semaglutide extended to all key KCCQ domains.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04788511.

Endovascular Ablation of the Right Greater Splanchnic Nerve in Heart Failure With Preserved Ejection Fraction: Rationale, Design and Lead-in Phase Results of the REBALANCE-HF Trial

OBJECTIVE

Splanchnic vasoconstriction augments transfer of blood volume from the abdomen into the thorax, which may increase filling pressures and hemodynamic congestion in patients with noncompliant hearts. Therapeutic interruption of splanchnic nerve activity holds promise to reduce hemodynamic congestion in patients with heart failure with preserved ejection fraction (HFpEF). Here we describe (1) the rationale and design of the first sham-controlled, randomized clinical trial of splanchnic nerve ablation for HFpEF and (2) the 12-month results of the lead-in (open-label) trial's participants.

METHODS

REBALANCE-HF is a prospective, multicenter, randomized, double-blinded, sham-controlled clinical trial of endovascular, transcatheter, right-sided greater splanchnic nerve ablation for volume management (SAVM) in patients with HFpEF. The primary objectives are to evaluate the safety and efficacy of SAVM and identify responder characteristics to inform future studies. The trial consists of an open-label lead-in phase followed by the randomized, sham-controlled phase. The primary efficacy endpoint is the reduction in pulmonary capillary wedge pressure (PCWP) at 1-month follow-up compared to baseline during passive leg raise and 20W exercise. Secondary and exploratory endpoints include health status (Kansas City Cardiomyopathy Questionnaire), 6-minute walk test distance, New York Heart Association class, and NTproBNP levels at 3, 6 and 12 months. The primary safety endpoint is device- or procedure-related serious adverse events at the 1-month follow-up.

RESULTS

The lead-in phase of the study, which enrolled 26 patients with HFpEF who underwent SAVM, demonstrated favorable safety outcomes and reduction in exercise PCWP at 1 month post-procedure and improvements in all secondary endpoints at 6 and 12 months of follow-up. The randomized phase of the trial (n = 44 SAVM; n = 46 sham) has completed enrollment, and follow-up is ongoing.

CONCLUSION

REBALANCE-HF is the first sham-controlled randomized clinical trial of greater splanchnic nerve ablation in HFpEF. Initial 12-month open-label results are promising, and the results of the randomized portion of the trial will inform the design of a future pivotal clinical trial. SAVM may offer a promising therapeutic option for patients with HFpEF.

TRIAL REGISTRATION

NCT04592445.

Artificial intelligence-enabled ECG for left ventricular diastolic function and filling pressure

Assessment of left ventricular diastolic function plays a major role in the diagnosis and prognosis of cardiac diseases, including heart failure with preserved ejection fraction. We aimed to develop an artificial intelligence (AI)-enabled electrocardiogram (ECG) model to identify echocardiographically determined diastolic dysfunction and increased filling pressure. We trained, validated, and tested an AI-enabled ECG in 98,736, 21,963, and 98,763 patients, respectively, who had an ECG and echocardiographic diastolic function assessment within 14 days with no exclusion criteria. It was also tested in 55,248 patients with indeterminate diastolic function by echocardiography. The model was evaluated using the area under the curve (AUC) of the receiver operating characteristic curve, and its prognostic performance was compared to echocardiography. The AUC for detecting increased filling pressure was 0.911. The AUCs to identify diastolic dysfunction grades ≥1, ≥2, and 3 were 0.847, 0.911, and 0.943, respectively. During a median follow-up of 5.9 years, 20,223 (20.5%) died. Patients with increased filling pressure predicted by AI-ECG had higher mortality than those with normal filling pressure, after adjusting for age, sex, and comorbidities in the test group (hazard ratio (HR) 1.7, 95% CI 1.645-1.757) similar to echocardiography and in the indeterminate group (HR 1.34, 95% CI 1.298-1.383). An AI-enabled ECG identifies increased filling pressure and diastolic function grades with a good prognostic value similar to echocardiography. AI-ECG is a simple and promising tool to enhance the detection of diseases associated with diastolic dysfunction and increased diastolic filling pressure.

Obesity in heart failure with preserved ejection fraction: Insights from the REDUCE LAP-HF II trial

AIMS

Obesity is causally related to the development of heart failure with preserved ejection fraction (HFpEF) but complicates the diagnosis and treatment of this disorder. We aimed to determine the relationship between severity of obesity and clinical, echocardiographic and haemodynamic parameters in a large cohort of patients with documented HFpEF.

METHODS AND RESULTS

The REDUCE LAP-HF II trial randomized 626 patients with ejection fraction ≥40% and exercise pulmonary capillary wedge pressure (PCWP) ≥25 mmHg to atrial shunt or sham procedure. We tested for associations between body mass index (BMI), clinical characteristics, cardiac structural and functional abnormalities, physical limitations, quality of life and outcomes with atrial shunt therapy. Overall, 60.9% of patients had BMI ≥30 kg/m2 . As the severity of obesity increased, symptoms (Kansas City Cardiomyopathy Questionnaire score) and 6-min walk distance worsened. More severe obesity was associated with lower natriuretic peptide levels despite more cardiac remodelling, higher cardiac filling pressures, and higher cardiac output. Lower cut points for E/e' were needed to identify elevated PCWP in more obese patients. Strain measurements in all four chambers were maintained as BMI increased. Pulmonary vascular resistance at rest and exercise decreased with higher BMI. Obesity was associated with more first and recurrent heart failure events. However, there was no significant interaction between obesity and treatment effects of the atrial shunt.

CONCLUSIONS

Increasing severity of obesity was associated with greater cardiac remodelling, higher right and left ventricular filling pressures, higher cardiac output and increased subsequent heart failure events. Despite significant obesity, many HFpEF patients have preserved right heart and pulmonary vascular function and thus, may be appropriate candidates for atrial shunt therapy.

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.

Prevalence and incidence of diastolic dysfunction in atrial fibrillation: clinical implications

BACKGROUND AND AIMS

Atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) are intimately associated disorders; HFpEF may be overlooked in AF when symptoms are simply attributed to dysrhythmia, and incident AF may identify patients at risk for developing diastolic dysfunction (DD). This study aimed to investigate the prevalence and incidence of DD in patients with new-onset AF compared with sinus rhythm (SR).

METHODS

Adults with new-onset AF (n = 1747) or SR (n = 29 623) and no structural heart disease were identified. Propensity score matching was performed (1:3 ratio) between AF and SR based on age, sex, body mass index, and comorbidities. Severe DD (SDD) was defined by ≥3/four abnormal parameters (medial e', medial E/e', tricuspid regurgitation velocity, and left atrial volume index) and ≥moderate DD (>MDD) by ≥2/4. Annualized changes in DD indices were determined.

RESULTS

New-onset AF was independently associated with SDD (8% vs. 3%) and ≥MDD (25% vs. 16%); 62% of patients with AF had high-risk H2FPEF scores, and 5% had clinically recognized HFpEF. Over a median follow-up of 3.2 (interquartile range 1.6-5.8) years, DD progressed two-four-fold more rapidly in those with new-onset AF (P < .001 for all). The risk for incident DD was increased in new-onset AF [hazard ratio (95% confidence interval) 2.69 (2.19-3.32) for SDD and 1.73 (1.49-2.02) for ≥MDD].

CONCLUSIONS

Patients with new-onset AF display high-risk features for HFpEF at diagnosis, emphasizing the importance of evaluating for HFpEF among symptomatic patients with AF. Patients with new-onset AF have accelerated progression in DD over time, which may identify patients with preclinical HFpEF, where preventive therapies may be tested.

Semaglutide in Patients With Obesity and Heart Failure Across Mildly Reduced or Preserved Ejection Fraction

BACKGROUND

Many therapies for heart failure (HF) have shown differential impact across the spectrum of left ventricular ejection fraction (LVEF).

OBJECTIVES

In this prespecified analysis, the authors assessed the effects of semaglutide across the baseline LVEF strata in patients with the obesity phenotype of HF with preserved ejection fraction (HFpEF) in the STEP-HFpEF (Semaglutide Treatment Effect in People with obesity and HFpEF) trial.

METHODS

STEP-HFpEF randomized 529 patients (263 semaglutide; 266 placebo). For this prespecified analysis, patients were categorized into 3 groups based on LVEF: 45% to 49% (n = 85), 50% to 59% (n = 215), and ≥60% (n = 229).

RESULTS

At 52 weeks, semaglutide improved the dual primary endpoints of Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (estimated treatment difference: EF [ejection fraction] 45%-49%: 5.0 points [95% CI: -2.7 to 12.8 points], EF 50%-59%: 9.8 points [95% CI: 5.0 to 14.6 points], and EF ≥60%: 7.4 points [95% CI: 2.8 to 12.0 points]; P interaction = 0.56) and body weight (EF: 45%-49%: -7.6 [95% CI: -10.7 to -4.4], EF 50%-59%: -10.6 [95% CI: -12.6 to -8.6] and EF ≥60%: -11.9 [95% CI: -13.8 to -9.9]; P interaction = 0.08), to a similar extent across LVEF categories. Likewise, LVEF did not influence the benefit of semaglutide on confirmatory secondary endpoints: 6-minute walk distance (P interaction = 0.19), hierarchal composite endpoint (P interaction = 0.43), and high-sensitivity C-reactive protein (P interaction = 0.26); or exploratory endpoint of N-terminal pro-brain natriuretic peptide (P interaction = 0.96). Semaglutide was well-tolerated across LVEF categories.

CONCLUSIONS

In patients with HFpEF and obesity, semaglutide 2.4 mg improved symptoms, physical limitations, and exercise function, and reduced inflammation and body weight to a similar extent across LVEF categories. These data support treatment with semaglutide in patients with the obesity phenotype of HFpEF regardless of LVEF. (Research Study to Investigate How Well Semaglutide Works in People Living With Heart Failure and Obesity [STEP-HFpEF]; NCT04788511).

Effect of Dapagliflozin on 6-Minute Walk Distance in Heart Failure With Preserved Ejection Fraction: PRESERVED-HF

BACKGROUND

Heart failure with preserved ejection fraction is associated with significant functional limitations, yet treatments for improving exercise performance have been elusive. We sought to explore the association between prespecified patient characteristics and changes in 6-minute walk distance that constitute a clinically significant response to dapagliflozin.

METHODS

We performed a responder analysis to understand patient characteristics associated with clinically meaningful improvement in 6-minute walk test (6MWT) distance ≥15 m among patients randomized to 12 weeks of dapagliflozin versus placebo in the double-blind PRESERVED-HF trial (Effects of Dapagliflozin on Biomarkers, Symptoms and Functional Status in Patients With Preserved Ejection Fraction Heart Failure).

RESULTS

A total of 289 randomized patients had 6MWT distance completed at baseline and 12 weeks. Patients randomized to dapagliflozin improved walking distance by ≥15 m more frequently than those on placebo (n=64, 44% versus n=48, 34%). After adjusting for baseline covariates, patients randomized to dapagliflozin were more likely to experience a clinically meaningful improvement in 6MWT distance compared with those that received placebo (adjusted odds ratio, 1.66 [95% CI, 1.00-2.75]; P=0.05). Dapagliflozin-treated patients were also less likely to have a ≥15 m reduction in 6MWT distance compared with placebo-treated patients (adjusted odds ratio, 0.56 [95% CI, 0.33-0.94]; P=0.03). These results were consistent across all prespecified subgroups (all P values for interaction were not significant).

CONCLUSIONS

Compared with those on placebo, patients with heart failure with preserved ejection fraction randomized to dapagliflozin were more likely to experience a clinically meaningful improvement and less likely to experience a deterioration in physical function over 12 weeks as measured by 6MWT distance. Beneficial response to dapagliflozin was consistent across prespecified subgroups.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03030235.

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).

Feasibility of Noninvasive Assessment of Cardiac Output during Exercise in Healthy Adults by a Novel Elaboration on Systolic Time Intervals

BACKGROUND

Although assessment of cardiovascular hemodynamics during exercise can provide clinical insights, it is challenging to acquire it in clinical settings.

OBJECTIVES

Accordingly, this preliminary study was to determine whether a novel elaboration on systolic time interval measures (eSTICO) method of quantifying cardiac output and stroke volume was comparable to those obtained using a validated soluble gas (open circuit CO measure [OpCircCO]) method or calculation based on oxygen consumption (oxygen consumption-based CO [VO2CO]) during exercise.

METHODS

For the present study, 14 healthy subjects (male: n = 12, female: n = 2) performed incremental exercise on a recumbent cycle ergometer. At rest and during exercise, cardiac output (CO) was obtained via the eSTICO method, while the OpenCircCO and VO2CO measures were obtained at the last minute of each workload.

RESULTS

At peak, there was no difference between eSTICO and OpCircCO (12.39 ± 3.06 vs. 13.96 ± 2.47 L/min, p > 0.05), while there was a slight difference between eSTICO and VO2CO (12.39 ± 3.06 vs. 14.28 ± 2.55 L/min, p < 0.05). When we performed correlation analysis with all subjects and all measures of CO at all WL, between eSTICO and OpenCircCO, there was a good relationship (r = 0.707, p < 0.001) with a Bland and Altman agreement analysis demonstrating a -1.6 difference (95% LoA: -6.3-3.5). Between eSTICO and VO2CO, we observed an r = 0.865 (p < 0.001) and a Bland and Altman agreement analysis with a -1.2 difference (95% LoA: -4.8-2.4).

CONCLUSION

A novel exploitation of cardiac hemodynamics using systolic timing intervals may allow a relatively good assessment of CO during exercise in healthy adults.

A big STEP for treatment of heart failure with preserved ejection fraction

In the STEP-HFpEF trial, 2.4 mg semaglutide produced marked improvements in heart failure-related symptoms, physical limitations, and exercise function, and reduced inflammation and body weight in individuals with obesity HFpEF phenotype. These data usher in a new paradigm of targeting obesity as a therapeutic strategy in HFpEF.

Obesity, Cardiorenal Comorbidities, and Risk of Hospitalization in Patients With Heart Failure With Preserved Ejection Fraction

OBJECTIVE

To compare clinical features of patients with obesity-related heart failure (HF) with preserved ejection fraction (HFpEF) with those of patients with similar body mass index (BMI) but no HF and to examine the association between degree of obesity and risk for hospitalizations.

METHODS

This was a retrospective analysis of 22,750 adults from a large US electronic health care data set (January 1, 2012, through July 31, 2019), including 4975 with HFpEF. Baseline characteristics were compared between patients with HFpEF and a control group matched on BMI, age, sex, and year of BMI record. Risk of first hospitalization was analyzed in the HFpEF sample with negative binomial and Cox proportional hazards models, adjusted for baseline comorbidities.

RESULTS

Compared with controls without HF matched on BMI, age, sex, and year of BMI record, patients with HFpEF displayed worse kidney function, greater estimated plasma volume, and more cardiovascular comorbidities. Within the HFpEF cohort, patients with higher degree of obesity were younger and had fewer concomitant cardiovascular comorbidities than those with lower degree of obesity. The mean number of HF-related hospitalizations increased with higher degree of obesity (9.6 to 15.7/100 patient-years; P=.002), but higher degree of obesity was not associated with increased risk of non-HF-related hospitalizations.

CONCLUSION

Among persons with obesity, increasing cardiorenal dysfunction and volume overload differentiate those with HFpEF. Among persons with established HFpEF, those with higher degree of obesity are younger and have fewer cardiovascular comorbidities but display a unique increased risk of HF-related hospitalizations, even as risk for other hospitalizations is not different.

Semaglutide in Patients with Heart Failure with Preserved Ejection Fraction and Obesity

BACKGROUND

Heart failure with preserved ejection fraction is increasing in prevalence and is associated with a high symptom burden and functional impairment, especially in persons with obesity. No therapies have been approved to target obesity-related heart failure with preserved ejection fraction.

METHODS

We randomly assigned 529 patients who had heart failure with preserved ejection fraction and a body-mass index (the weight in kilograms divided by the square of the height in meters) of 30 or higher to receive once-weekly semaglutide (2.4 mg) or placebo for 52 weeks. The dual primary end points were the change from baseline in the Kansas City Cardiomyopathy Questionnaire clinical summary score (KCCQ-CSS; scores range from 0 to 100, with higher scores indicating fewer symptoms and physical limitations) and the change in body weight. Confirmatory secondary end points included the change in the 6-minute walk distance; a hierarchical composite end point that included death, heart failure events, and differences in the change in the KCCQ-CSS and 6-minute walk distance; and the change in the C-reactive protein (CRP) level.

RESULTS

The mean change in the KCCQ-CSS was 16.6 points with semaglutide and 8.7 points with placebo (estimated difference, 7.8 points; 95% confidence interval [CI], 4.8 to 10.9; P<0.001), and the mean percentage change in body weight was -13.3% with semaglutide and -2.6% with placebo (estimated difference, -10.7 percentage points; 95% CI, -11.9 to -9.4; P<0.001). The mean change in the 6-minute walk distance was 21.5 m with semaglutide and 1.2 m with placebo (estimated difference, 20.3 m; 95% CI, 8.6 to 32.1; P<0.001). In the analysis of the hierarchical composite end point, semaglutide produced more wins than placebo (win ratio, 1.72; 95% CI, 1.37 to 2.15; P<0.001). The mean percentage change in the CRP level was -43.5% with semaglutide and -7.3% with placebo (estimated treatment ratio, 0.61; 95% CI, 0.51 to 0.72; P<0.001). Serious adverse events were reported in 35 participants (13.3%) in the semaglutide group and 71 (26.7%) in the placebo group.

CONCLUSIONS

In patients with heart failure with preserved ejection fraction and obesity, treatment with semaglutide (2.4 mg) led to larger reductions in symptoms and physical limitations, greater improvements in exercise function, and greater weight loss than placebo. (Funded by Novo Nordisk; STEP-HFpEF ClinicalTrials.gov number, NCT04788511.).

Cardiac and Metabolic Effects of Dapagliflozin in Heart Failure With Preserved Ejection Fraction: The CAMEO-DAPA Trial

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors reduce risk of hospitalization for heart failure in patients who have heart failure with preserved ejection fraction (HFpEF), but the hemodynamic mechanisms underlying these benefits remain unclear. This study sought to determine whether treatment with dapagliflozin affects pulmonary capillary wedge pressure (PCWP) at rest and during exercise in patients with HFpEF.

METHODS

This was a single-center, double-blinded, randomized, placebo-controlled trial testing the effects of 10 mg of dapagliflozin once daily in patients with HFpEF. Patients with New York Heart Association class II or III heart failure, ejection fraction ≥50%, and elevated PCWP during exercise were recruited. Cardiac hemodynamics were measured at rest and during exercise using high-fidelity micromanometers at baseline and after 24 weeks of treatment. The primary end point was a change from baseline in rest and peak exercise PCWPs that incorporated both measurements, and was compared using a mixed-model likelihood ratio test. Key secondary end points included body weight and directly measured blood and plasma volumes. Expired gas analysis was performed evaluate oxygen transport in tandem with arterial lactate sampling.

RESULTS

Among 38 patients completing baseline assessments (median age 68 years; 66% women; 71% obese), 37 completed the trial. Treatment with dapagliflozin resulted in reduction in the primary end point of change in PCWP at rest and during exercise at 24 weeks relative to treatment with placebo (likelihood ratio test for overall changes in PCWP; P<0.001), with lower PCWP at rest (estimated treatment difference [ETD], -3.5 mm Hg [95% CI, -6.6 to -0.4]; P=0.029) and maximal exercise (ETD, -5.7 mm Hg [95% CI, -10.8 to -0.7]; P=0.027). Body weight was reduced with dapagliflozin (ETD, -3.5 kg [95% CI, -5.9 to -1.1]; P=0.006), as was plasma volume (ETD, -285 mL [95% CI, -510 to -60]; P=0.014), but there was no significant effect on red blood cell volume. There were no differences in oxygen consumption at 20-W or peak exercise, but dapagliflozin decreased arterial lactate at 20 W (-0.70 ± 0.77 versus 0.37 ± 1.29 mM; P=0.006).

CONCLUSIONS

In patients with HFpEF, treatment with dapagliflozin reduces resting and exercise PCWP, along with the favorable effects on plasma volume and body weight. These findings provide new insight into the hemodynamic mechanisms of benefit with sodium-glucose cotransporter-2 inhibitors in HFpEF.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04730947.

Semaglutide in HFpEF across obesity class and by body weight reduction: a prespecified analysis of the STEP-HFpEF trial

In the STEP-HFpEF trial, semaglutide improved symptoms, physical limitations and exercise function and reduced body weight in patients with obesity phenotype of heart failure and preserved ejection fraction (HFpEF). This prespecified analysis examined the effects of semaglutide on dual primary endpoints (change in Kansas City Cardiomyopathy Questionnaire-Clinical Summary Score (KCCQ-CSS) and body weight) and confirmatory secondary endpoints (change in 6-minute walk distance (6MWD), hierarchical composite (death, HF events, change in KCCQ-CSS and 6MWD) and change in C-reactive protein (CRP)) across obesity classes I-III (body mass index (BMI) 30.0-34.9 kg m-2, 35.0-39.9 kg m-2 and ≥40 kg m-2) and according to body weight reduction with semaglutide after 52 weeks. Semaglutide consistently improved all outcomes across obesity categories (P value for treatment effects × BMI interactions = not significant for all). In semaglutide-treated patients, improvements in KCCQ-CSS, 6MWD and CRP were greater with larger body weight reduction (for example, 6.4-point (95% confidence interval (CI): 4.1, 8.8) and 14.4-m (95% CI: 5.5, 23.3) improvements in KCCQ-CSS and 6MWD for each 10% body weight reduction). In participants with obesity phenotype of HFpEF, semaglutide improved symptoms, physical limitations and exercise function and reduced inflammation and body weight across obesity categories. In semaglutide-treated patients, the magnitude of benefit was directly related to the extent of weight loss. Collectively, these data support semaglutide-mediated weight loss as a key treatment strategy in patients with obesity phenotype of HFpEF. ClinicalTrials.gov identifier: NCT04788511 .

Decoupling of Hemodynamics and Congestive Symptoms in Obese Patients With Heart Failure

BACKGROUND

Prior studies indicate significant physiological differences between obese and nonobese patients with heart failure (HF), but none have evaluated differences in hemodynamic patterns in these patient populations during treatment for acute decompensated HF (ADHF).

OBJECTIVES

In this study, we assessed differences in hemodynamic trends between obese and nonobese patients during treatment for ADHF.

METHODS

Obese (body mass index (BMI) >30, n = 63) and nonobese (BMI < 25, n = 69) patients with ADHF in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) study who had pulmonary artery catheterization data available through the duration of treatment were evaluated. Hemodynamics were analyzed at baseline and optimal day. Changes in BNP levels, weight, creatinine, BUN, 6MWT, orthopnea and dyspnea scores were assessed.

RESULTS

Despite similar baseline hemodynamics, obese patients had significantly less absolute and relative pulmonary arterial wedge pressure (PAWP) reduction (-16 ± 28 vs -32 ± 29%; P = 0.03) during treatment. Obese patients also had higher PAWPs (19.9 + 8 vs 15.5 + 6.8 mmHg; P = 0.01) and PA pressures at optimization compared with nonobese patients. Obese and nonobese patients had similar relative improvements in weight, BNP, 6-minute walk test distance, dyspnea and orthopnea scores, and similar changes in creatinine and BUN levels.

CONCLUSIONS

Obese patients treated for ADHF display less reduction in invasively measured left heart filling pressures, despite similar improvements in symptoms, weight loss, and noninvasive surrogates of congestion. Our findings suggest a degree of decoupling between left heart filling pressures and congestive symptoms in obese patients undergoing treatment for ADHF.

Hypoxaemia in patients with heart failure and preserved ejection fraction

AIMS

It is widely held that heart failure (HF) does not cause exertional hypoxaemia, based upon studies in HF with reduced ejection fraction, but this may not apply to patients with HF and preserved ejection fraction (HFpEF). Here, we characterize the prevalence, pathophysiology, and clinical implications of exertional arterial hypoxaemia in HFpEF.

METHODS AND RESULTS

Patients with HFpEF (n = 539) and no coexisting lung disease underwent invasive cardiopulmonary exercise testing with simultaneous blood and expired gas analysis. Exertional hypoxaemia (oxyhaemoglobin saturation <94%) was observed in 136 patients (25%). As compared to those without hypoxaemia (n = 403), patients with hypoxaemia were older and more obese. Patients with HFpEF and hypoxaemia had higher cardiac filling pressures, higher pulmonary vascular pressures, greater alveolar-arterial oxygen difference, increased dead space fraction, and greater physiologic shunt compared to those without hypoxaemia. These differences were replicated in a sensitivity analysis where patients with spirometric abnormalities were excluded. Regression analyses revealed that increases in pulmonary arterial and pulmonary capillary pressures were related to lower arterial oxygen tension (PaO2 ), especially during exercise. Body mass index (BMI) was not correlated with the arterial PaO2 , and hypoxaemia was associated with increased risk for death over 2.8 (interquartile range 0.7-5.5) years of follow-up, even after adjusting for age, sex, and BMI (hazard ratio 2.00, 95% confidence interval 1.01-3.96; p = 0.046).

CONCLUSION

Between 10% and 25% of patients with HFpEF display arterial desaturation during exercise that is not ascribable to lung disease. Exertional hypoxaemia is associated with more severe haemodynamic abnormalities and increased mortality. Further study is required to better understand the mechanisms and treatment of gas exchange abnormalities in HFpEF.

Exercise-Induced Left Atrial Hypertension in Heart Failure With Preserved Ejection Fraction

BACKGROUND

Many patients with heart failure and preserved ejection fraction have no overt volume overload and normal resting left atrial (LA) pressure.

OBJECTIVES

This study sought to characterize patients with normal resting LA pressure (pulmonary capillary wedge pressure [PCWP] <15 mm Hg) but exercise-induced left atrial hypertension (EILAH).

METHODS

The REDUCE LAP-HF II (A Study to Evaluate the Corvia Medical, Inc. IASD System II to Reduce Elevated Left Atrial Pressure in Patients With Heart Failure) trial randomized 626 patients with ejection fraction ≥40% and exercise PCWP ≥25 mm Hg to atrial shunt or sham procedure. The primary trial outcome, a hierarchical composite of death, heart failure hospitalization, intensification of diuretics, and change in health status was compared between patients with EILAH and those with heart failure and resting left atrial hypertension (RELAH).

RESULTS

Patients with EILAH (29%) had similar symptom severity, but lower natriuretic peptide levels, higher 6-minute walk distance, less atrial fibrillation, lower left ventricular mass, smaller LA volumes, lower E/e', and better LA strain. PCWP was lower at rest, but had a larger increase with exercise in EILAH. Neither group as a whole had a significant effect from shunt therapy vs sham. Patients with EILAH were more likely to have characteristics associated with atrial shunt responsiveness (peak exercise pulmonary vascular resistance <1.74 WU) and no pacemaker (63% vs 46%; P < 0.001). The win ratio for the primary outcome was 1.56 (P = 0.08) in patients with EILAH and 1.51 (P = 0.04) in those with RELAH when responder characteristics were present.

CONCLUSIONS

Patients with EILAH had similar symptom severity but less advanced myocardial and pulmonary vascular disease. This important subgroup may be difficult to diagnose without invasive exercise hemodynamics, but it has characteristics associated with favorable response to atrial shunt therapy. (A Study to Evaluate the Corvia Medical, Inc. IASD System II to Reduce Elevated Left Atrial Pressure in Patients With Heart Failure [REDUCE LAP-HF TRIAL II]; NCT03088033).

Design and Baseline Characteristics of STEP-HFpEF Program Evaluating Semaglutide in Patients With Obesity HFpEF Phenotype

BACKGROUND

The majority of patients with heart failure with preserved ejection fraction (HFpEF) have the obesity phenotype, but no therapies specifically targeting obesity in HFpEF exist.

OBJECTIVES

The aim of this study was to describe the design and baseline characteristics of 2 trials of semaglutide, a glucagon-like peptide-1 receptor agonist, in patients with the obesity HFpEF phenotype: STEP-HFpEF (Semaglutide Treatment Effect in People with obesity and HFpEF; NCT04788511) and STEP-HFpEF DM (Semaglutide Treatment Effect in People with obesity and HFpEF and type 2 diabetes; NCT04916470).

METHODS

Both STEP-HFpEF and STEP-HFpEF DM are international multicenter, double-blind, placebo-controlled trials that randomized adults with HFpEF and a body mass index ≥30 kg/m2 to once-weekly semaglutide at a dose of 2.4 mg or placebo. Participants were eligible if they had a left ventricular ejection fraction (LVEF) ≥45%; NYHA functional class II to IV; a Kansas City Cardiomyopathy Questionnaire (KCCQ)-Clinical Summary Score (CSS) <90 points; and ≥1 of the following: elevated filling pressures, elevated natriuretic peptides plus structural echocardiographic abnormalities, recent heart failure hospitalization plus ongoing diuretic use, and/or structural abnormalities. The dual primary endpoints are the 52-week change in the KCCQ-CSS and body weight.

RESULTS

In STEP-HFpEF and STEP-HFpEF DM (N = 529 and N = 617, respectively), nearly half were women, and most had severe obesity (median body mass index of 37 kg/m2) with typical features of HFpEF (median LVEF of 57%, frequent comorbidities, and elevated natriuretic peptides). Most participants received diuretic agents and renin-angiotensin blockers at baseline, and approximately one-third were on mineralocorticoid receptor antagonists. Sodium-glucose cotransporter-2 inhibitor use was rare in STEP-HFpEF but not in STEP HFpEF DM (32%). Patients in both trials had marked symptomatic and functional impairments (KCCQ-CSS ∼59 points, 6-minute walking distance ∼300 m).

CONCLUSIONS

In total, STEP-HFpEF program randomized 1,146 participants with the obesity phenotype of HFpEF and will determine whether semaglutide improves symptoms, physical limitations, and exercise function in addition to weight loss in this vulnerable group.

Biventricular cardiac power reserve in heart failure with preserved ejection fraction

AIMS

Cardiac and extracardiac abnormalities play important roles in heart failure with preserved ejection fraction (HFpEF). Biventricular cardiac power output (BCPO) quantifies the total rate of hydraulic work performed by both ventricles, suggesting that it may help to identify patients with HFpEF and more severe cardiac impairments to better individualize treatment.

METHODS AND RESULTS

Patients with HFpEF (n = 398) underwent comprehensive echocardiography and invasive cardiopulmonary exercise testing. Patients were categorized as low BCPO reserve (n = 199, < median of 1.57 W) or preserved BCPO reserve (n = 199). As compared to those with preserved BCPO reserve, those with low reserve were older and leaner, with more atrial fibrillation, higher N-terminal pro-B-type natriuretic peptide levels, worse renal function, more impaired left ventricular (LV) global longitudinal strain, worse LV diastolic function and right ventricular longitudinal function. Cardiac filling pressures and pulmonary artery pressures at rest were higher in low BCPO reserve, but central pressures were similar during exercise to those with preserved BCPO reserve. Exertional systemic and pulmonary vascular resistances were higher and exercise capacity was more impaired in those with low BCPO reserve. Reduced BCPO reserve was associated with increased risk for the composite endpoint of heart failure hospitalization or death over 2.9 (interquartile range 0.9-4.5) years of follow-up (hazard ratio 2.77, 95% confidence interval 1.73-4.42, p < 0.0001).

CONCLUSIONS

Inability to enhance BCPO during exercise is associated with more advanced HFpEF, increased systemic and pulmonary vascular resistance, reduced exercise capacity and increased adverse events in patients with HFpEF. Novel therapies that enhance biventricular reserve merit further investigation for patients with this phenotype.

Dapagliflozin Improves Heart Failure Symptoms and Physical Limitations Across the Full Range of Ejection Fraction: Pooled Patient-Level Analysis From DEFINE-HF and PRESERVED-HF Trials

BACKGROUND

Patients with heart failure (HF) have a high burden of symptoms and physical limitations, regardless of ejection fraction (EF). Whether the benefits of SGLT2 (sodium-glucose cotransporter-2) inhibitors on these outcomes vary across the full range of EF remains unclear.

METHODS

Patient-level data were pooled from the DEFINE-HF trial (Dapagliflozin Effects on Biomarkers, Symptoms, and Functional Status in Patients With Heart Failure With Reduced Ejection Fraction) of 263 participants with reduced EF (≤40%), and PRESERVED-HF trial (Effects of Dapagliflozin on Biomarkers, Symptoms and Functional Status in Patients With Preserved Ejection Fraction Heart Failure) of 324 participants with preserved EF (≥45%). Both were randomized, double-blind 12-week trials of dapagliflozin versus placebo, recruiting participants with New York Heart Association class II or higher and elevated natriuretic peptides. The effect of dapagliflozin on the change in the Kansas City Cardiomyopathy Questionnaire (KCCQ) Clinical Summary Score (CSS) at 12 weeks was tested with ANCOVA adjusted for sex, baseline KCCQ, EF, atrial fibrillation, estimated glomerular filtration rate, and type 2 diabetes. Interaction of dapagliflozin effects on KCCQ-CSS by EF was assessed using EF both categorically and continuously with restricted cubic spline. Responder analyses, examining proportions of patients with deterioration, and clinically meaningful improvements in KCCQ-CSS were conducted using logistic regression.

RESULTS

Of 587 patients randomized (293 dapagliflozin, 294 placebo), EF was ≤40, >40-≤60, and >60% in 262 (45%), 199 (34%), and 126 (21%), respectively. Dapagliflozin improved KCCQ-CSS at 12 weeks (placebo-adjusted difference 5.0 points [95% CI, 2.6-7.5]; P<0.001). This was consistent in participants with EF≤40 (4.6 points [95% CI, 1.0-8.1]; P=0.01), >40 to ≤60 (4.9 points [95% CI, 0.8-9.0]; P=0.02) and >60% (6.8 points [95% CI, 1.5-12.1]; P=0.01; Pinteraction=0.79). Benefits of dapagliflozin on KCCQ-CSS were also consistent when analyzing EF continuously (Pinteraction=0.94). In responder analyses, fewer dapagliflozin-treated patients had deterioration and more had small, moderate, and large KCCQ-CSS improvements versus placebo; these results were also consistent regardless of EF (all Pinteractionvalues nonsignificant).

CONCLUSIONS

In patients with HF, dapagliflozin significantly improves symptoms and physical limitations after 12 weeks of treatment, with consistent and clinically meaningful benefits across the full range of EF.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifiers: NCT02653482 and NCT03030235.

Iron deficiency in pulmonary vascular disease: pathophysiological and clinical implications

AIMS

Iron deficiency is common in pulmonary hypertension, but its clinical significance and optimal definition remain unclear.

METHODS AND RESULTS

Phenotypic data for 1028 patients enrolled in the Redefining Pulmonary Hypertension through Pulmonary Vascular Disease Phenomics study were analyzed. Iron deficiency was defined using the conventional heart failure definition and also based upon optimal cut-points associated with impaired peak oxygen consumption (peakVO2), 6-min walk test distance, and 36-Item Short Form Survey (SF-36) scores. The relationships between iron deficiency and cardiac and pulmonary vascular function and structure and outcomes were assessed. The heart failure definition of iron deficiency endorsed by pulmonary hypertension guidelines did not identify patients with reduced peakVO2, 6-min walk test, and SF-36 (P > 0.208 for all), but defining iron deficiency as transferrin saturation (TSAT) <21% did. Compared to those with TSAT ≥21%, patients with TSAT <21% demonstrated lower peakVO2 [absolute difference: -1.89 (-2.73 to -1.04) mL/kg/min], 6-min walk test distance [absolute difference: -34 (-51 to -17) m], and SF-36 physical component score [absolute difference: -2.5 (-1.3 to -3.8)] after adjusting for age, sex, and hemoglobin (all P < 0.001). Patients with a TSAT <21% had more right ventricular remodeling on cardiac magnetic resonance but similar pulmonary vascular resistance on catheterization. Transferrin saturation <21% was also associated with increased mortality risk (hazard ratio 1.63, 95% confidence interval 1.13-2.34; P = 0.009) after adjusting for sex, age, hemoglobin, and N-terminal pro-B-type natriuretic peptide.

CONCLUSION

The definition of iron deficiency in the 2022 European Society of Cardiology (ESC)/European Respiratory Society (ERS) pulmonary hypertension guidelines does not identify patients with lower exercise capacity or functional status, while a definition of TSAT <21% identifies patients with lower exercise capacity, worse functional status, right heart remodeling, and adverse clinical outcomes.

Left atrial enlargement is associated with pulmonary vascular disease in heart failure with preserved ejection fraction

AIMS

Elevated left atrial (LA) pressure is a pathophysiologic hallmark of heart failure with preserved ejection fraction (HFpEF). Chronically elevated LA pressure leads to LA enlargement, which may impair LA function and increase pulmonary pressures. We sought to evaluate the relationship between LA volume and pulmonary arterial haemodynamics in patients with HFpEF.

METHODS AND RESULTS

Data from 85 patients (aged 69 ± 8 years) who underwent exercise right heart catheterization and echocardiography were retrospectively analysed. All had symptoms of heart failure, left ventricular ejection fraction ≥50% and haemodynamic features of HFpEF. Patients were divided into LA volume index-based tertiles (≤34 ml/m2 , >34 to ≤45 ml/m2 , >45 ml/m2 ). A subgroup analysis was performed in patients with recorded LA global reservoir strain (n = 60), with reduced strain defined as ≤24%. Age, sex, body surface area and left ventricular ejection fraction were similar between volume groups. LA volume was associated with blunted increases in cardiac output with exercise (padjusted  <0.001), higher resting mean pulmonary artery pressure (padjusted  = 0.003), with similar wedge pressure (padjusted  = 1). Pulmonary vascular resistance (PVR) increased with increasing LA volume (padjusted  <0.001). Larger LA volumes featured reduced LA strain (padjusted  <0.001), with reduced strain associated with reduced PVR-compliance time (0.34 [0.28-0.40] vs. 0.38 [0.33-0.43], p = 0.03).

CONCLUSION

Increasing LA volume may be associated with more advanced pulmonary vascular disease in HFpEF, featuring higher PVR and pulmonary pressures. Reduced LA function, worse at increasing LA volumes, is associated with a disrupted PVR-compliance relationship, further augmenting impaired pulmonary haemodynamics.