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.

Management of Atrial Fibrillation Across the Spectrum of Heart Failure With Preserved and Reduced Ejection Fraction.

Atrial fibrillation (AF) is the most common arrhythmia among patients with heart failure (HF), and HF is the most common cause of death for patients presenting with clinical AF. AF is frequently associated with pathological atrial myocardial dysfunction and remodeling, a triad that has been called atrial myopathy. AF can be the cause or consequence of clinical HF, and the directionality varies between individual patients and across the spectrum of HF. Although initial trials suggested no advantage for a systematic rhythm control strategy in HF with reduced ejection fraction, recent data suggest that select patients may benefit from attempts to maintain sinus rhythm with catheter ablation. Preliminary data also show a close relationship among AF, left atrial myopathy, mitral regurgitation, and HF with preserved ejection, with potential clinical benefits to catheter ablation therapy. The modern management of AF in HF also requires consideration of the degree of atrial myopathy and chronicity of AF, in addition to the pathogenesis and phenotype of the underlying left ventricular HF. In this review, we summarize the contemporary management of AF and provide practical guidance and areas in need of future investigation.

Heart failure with preserved ejection fraction in patients with normal natriuretic peptide levels is associated with increased morbidity and mortality.

BACKGROUND: A substantial proportion of patients with heart failure (HF) with preserved ejection fraction (HFpEF) present with normal natriuretic peptide (NP) levels. The pathophysiology and natural history for this phenotype remain unclear. METHODS AND RESULTS: Consecutive subjects undergoing invasive cardiopulmonary exercise testing for unexplained dyspnoea at Mayo Clinic in 2006-18 were studied. Heart failure with preserved ejection fraction was defined as a pulmonary arterial wedge pressure (PAWP) ≥15 mmHg (rest) or ≥25 mmHg (exercise). Patients with HFpEF and normal NP [N-terminal of the pro-hormone B-type natriuretic peptide (NT-proBNP) < 125 ng/L] were compared with HFpEF with high NP (NT-proBNP ≥ 125 ng/L) and controls with normal haemodynamics. Patients with HFpEF and normal (n = 157) vs. high NP (n = 263) were younger, yet older than controls (n = 161), with an intermediate comorbidity profile. Normal NP HFpEF was associated with more left ventricular hypertrophy and worse diastolic function compared with controls, but better diastolic function, lower left atrial volumes, superior right ventricular function, and less mitral/tricuspid regurgitation compared with high NP HFpEF. Cardiac output (CO) reserve with exercise was preserved in normal NP HFpEF [101% predicted, interquartile range (IQR): 75-124%], but this was achieved only at the cost of higher left ventricular transmural pressure (LVTMP) (14 ± 6 mmHg vs. 7 ± 4 mmHg in controls, P < 0.001). In contrast, CO reserve was decreased in high NP HFpEF (85% predicted, IQR: 59-109%), with lower LVTMP (10 ± 8 mmHg) compared with normal NP HFpEF (P < 0.001), despite similar PAWP. Patients with high NP HFpEF displayed the highest event rates, but normal NP HFpEF still had 2.7-fold higher risk for mortality or HF readmissions compared with controls (hazard ratio: 2.74, 95% confidence interval: 1.02-7.32) after adjusting for age, sex, and body mass index. CONCLUSION: Patients with HFpEF and normal NP display mild diastolic dysfunction and preserved CO reserve during exercise, despite marked elevation in filling pressures. While clinical outcomes are not as poor compared with patients with high NP, patients with normal NP HFpEF exhibit increased risk of death or HF readmissions compared with patients without HF, emphasizing the importance of this phenotype.

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.

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.

Hospitalization for Heart Failure in the United States, UK, Taiwan, and Japan: An International Comparison of Administrative Health Records on 413,385 Individual Patients.

BACKGROUND: Registries show international variations in the characteristics and outcome of patients with heart failure (HF), but national samples are rarely large, and case selection may be biased owing to enrolment in academic centers. National administrative datasets provide large samples with a low risk of bias. In this study, we compared the characteristics, health care resource use (HRU) and outcomes of patients with primary HF hospitalizations (HFH) using electronic health records (EHR) from 4 high-income countries (United States, UK, Taiwan, Japan) on 3 continents. METHODS AND RESULTS: We used electronic health record to identify unplanned HFH between 2012 and 2014. We identified 231,512, 10,991, 36,900, and 133,982 patients with a primary HFH from the United States, the UK, Taiwan, and Japan, respectively. HFH per 100,000 population was highest in the United States and lowest in Taiwan. Fewer patients in Taiwan and Japan were obese or had chronic kidney disease. The length of hospital stay was shortest in the United States (median 4 days) and longer in the UK, Taiwan, and Japan (medians of 7, 9, and 17 days, respectively). HRU during hospitalization was highest in Japan and lowest in UK. Crude and direct standardized in-hospital mortality was lowest in the United States (direct standardized rates 1.8, 95% confidence interval 1.7%-1.9%) and progressively higher in Taiwan (direct standardized rates 3.9, 95% CI 3.8%-4.1%), the UK (direct standardized rates 6.4, 95% CI 6.1%-6.7%), and Japan (direct standardized rates 6.7, 95% CI 6.6%-6.8%). The 30-day all-cause (25.8%) and HF (7.2%) readmissions were highest in the United States and lowest in Japan (11.9% and 5.1%, respectively). CONCLUSIONS: Marked international variations in patient characteristics, HRU, and clinical outcomes exist; understanding them might inform health care policy and international trial design.

The hemodynamic spectrum of pulmonary vein stenosis from fibrosing mediastinitis.

A 63-year-old man presented with hemoptysis and progressive dyspnea. His echocardiogram was concerning for pulmonary hypertension (PH) and CT chest showed fibrosing mediastinitis with possible cardiac involvement. Right heart catheterization revealed PH at rest and worsened with exercise. CT findings and simultaneous measurement of pulmonary capillary wedge pressure (PCWP), left atrial pressure, and left ventricular pressure helped diagnose pulmonary vein (PV) stenosis as the etiology of his PH. Both upper pulmonary veins were stented, and repeat exercise hemodynamic study revealed a substantial reduction in pulmonary arterial pressure with improvement in subjective dyspnea, cardiac output reserve, mechanical efficiency, and ventilatory efficiency. Repeat right upper PCWP normalized, consistent with resolution of the PV stenosis.

Atrial mitral regurgitation: Characteristics and outcomes of transcatheter mitral valve edge-to-edge repair.

BACKGROUND: Mitral transcatheter edge-to-edge repair (MTEER) is an established therapeutic approach for mitral regurgitation (MR). Functional mitral regurgitation originating from atrial myopathy (A-FMR) has been described. OBJECTIVES: We sought to assess the clinical, echocardiographic and hemodynamic considerations in A-FMR patients undergoing MTEER. METHODS: From 2014 to 2020, patients undergoing MTEER for degenerative MR (DMR), functional MR (FMR), and mixed MR were assessed. A-FMR was defined by the presence of MR > moderate in severity; left ventricular (LV) ejection fraction (LVEF) ≥ 50%; and severe left atrial (LA) enlargement in the absence of LV dysfunction, leaflet pathology, or LV tethering. The diagnosis of A-FMR (vs. ventricular-FMR [V-FMR]) was confirmed by three independent echocardiographers. Baseline characteristics, procedural outcomes as well as clinical and echocardiographic follow-up are reported. Device success was defined as final MR grade ≤ moderate; MR reduction ≥1 grade; and final transmitral gradient <5 mmHg. RESULTS: 306 patients underwent MTEER, including DMR (62%), FMR (19%), and mixed MR (19%). FMR cases included 37 (63.8%) V-FMR and 21 (36.2%) A-FMR. Tricuspid regurgitation (≥ moderate) was higher in A-FMR (80.1%) compared to V-FMR (54%) and DMR (42%). Device success did not significantly differ between A-FMR and V-FMR (57% vs. 73%, p = 0.34) or DMR (57% vs. 64%, p = 1.0). The A-FMR cohort was less likely to achieve ≥3 grades of MR reduction compared to V-FMR (19% vs. 54%, p = 0.01) and DMR (19% vs. 49.7%, p = 0.01). Patients with V-FMR and DMR demonstrated significant reductions in mean left atrial pressure (LAP) and peak LA V-wave, though A-FMR did not (LAP -0.24 ± 4.9, p = 0.83; peak V-wave -1.76 ± 9.1, p = 0.39). In follow-up, echocardiographic and clinical outcomes were similar. CONCLUSIONS: In patients undergoing MTEER, A-FMR represents one-third of FMR cases. A-FMR demonstrates similar procedural success but blunted acute hemodynamic responses compared with DMR and V-FMR following MTEER. Dedicated studies specifically considering A-FMR are needed to discern the optimal therapeutic approaches.

Pathophysiologic importance of visceral adipose tissue in women with heart failure and preserved ejection fraction.

AIMS: Central obesity is a major risk factor for heart failure with preserved ejection fraction (HFpEF), particularly in women, but the mechanisms remain unclear. We hypothesized that sex-specific differences in visceral adipose tissue (VAT) content would differentially relate to haemodynamic severity of HFpEF in women and men. METHODS AND RESULTS: Abdominal computed tomography (CT) and invasive haemodynamic exercise testing were performed in 105 subjects with HFpEF (63 women) and 105 age-, sex-, and body mass index-matched controls. Visceral adipose tissue area was quantified by CT. As compared with control women, VAT area was 34% higher in women with HFpEF (186 ± 112 vs. 139 ± 72 cm2, P = 0.006), while VAT area was not significantly different in men with or without HFpEF (294 ± 158 vs. 252 ± 92 cm2, P = 0.1). During exercise, pulmonary capillary wedge pressure (PCWP) increased markedly and to similar extent in both men and women with HFpEF. Women with increased VAT area displayed 33% higher PCWP during exercise compared with women with normal VAT area (28 ± 10 vs. 21 ± 10 mmHg, P = 0.001), whereas exercise PCWP was similar in men with or without excess VAT (24 ± 9 vs. 25 ± 6, P = 0.89). In women, each 100 cm2 increase in VAT area was associated with a 4.0 mmHg higher PCWP (95% CI 2.1, 6.0 mmHg; P < 0.0001), but there was no such relationship in men (interaction P = 0.009). CONCLUSIONS: These data suggest that accumulation of excess VAT plays a distinct and important role in the pathophysiology of HFpEF preferentially in women. Further research is needed to better understand the mechanisms and treatment implications for visceral fat in HFpEF.

Salutary Acute Effects of Exercise on Central Hemodynamics in Heart Failure With Preserved Ejection Fraction.

BACKGROUND: A warmup period of priming exercise has been shown to improve peripheral oxygen transport in older adults. We sought to determine the acute effects of priming exercise on central hemodynamics at rest and during a repeat exercise in heart failure with preserved ejection fraction (HFpEF). METHODS AND RESULTS: This is a post hoc analysis from 3 studies. Patients with HFpEF (n = 42) underwent cardiac catheterization with simultaneous expired gas analysis at rest and during exercise (20 W for 5 minutes, priming exercise). Measurements were then repeated at rest and during a second bout of exercise at a 20-W workload (second exercise). During the priming exercise, patients with HFpEF displayed dramatic increases in biventricular filling pressures and exercise-induced pulmonary hypertension. After the priming exercise at rest, biventricular filling pressures and pulmonary artery (PA) pressures were lower and lung tidal volume was increased. During the second bout of exercise, biventricular filling (PA wedge pressure, 29 ± 8 mm Hg at second exercise vs 32 ± 7 mm Hg at first exercise, P = .0003) and PA pressures were lower, and PA compliance increased. CONCLUSIONS: This study shows that short duration, submaximal priming exercise attenuates the pathologic increases in filling pressures, improving pulmonary vascular hemodynamics at rest and during repeat exercise in patients with HFpEF.

The ß-Adrenergic Agonist Albuterol Improves Pulmonary Vascular Reserve in Heart Failure With Preserved Ejection Fraction.

RATIONALE: Pulmonary vascular resistance fails to decrease appropriately during exercise in patients with heart failure with preserved ejection fraction (HFpEF). Interventions that enhance pulmonary vasodilation might be beneficial in this cohort but could also worsen left atrial hypertension, exacerbating lung congestion. Intravenous ß-agonists reduce pulmonary vascular resistance but are not suitable for chronic use. OBJECTIVE: We hypothesized that the inhaled ß-adrenergic agonist albuterol would improve pulmonary vasodilation during exercise in patients with HFpEF, without increasing left heart filling pressures. METHODS AND RESULTS: We performed a randomized, double-blind, placebo-controlled trial testing the effects of inhaled albuterol on resting and exercise hemodynamics in subjects with HFpEF using high-fidelity micromanometer catheters and expired gas analysis. The primary end point was pulmonary vascular resistance during exercise. Subjects with HFpEF (n=30) underwent resting and exercise hemodynamic assessment and were then randomized 1:1 to inhaled, nebulized albuterol or placebo. Rest and exercise hemodynamic testing was then repeated. Albuterol improved the primary end point of exercise pulmonary vascular resistance as compared with placebo (-0.6±0.5 versus +0.1±0.7 WU; P=0.003). Albuterol enhanced cardiac output reserve and right ventricular pulmonary artery coupling, reduced right atrial and pulmonary artery pressures, improved pulmonary artery compliance, and enhanced left ventricular transmural distending pressure (all P <0.01), with no increase in pulmonary capillary hydrostatic pressures. CONCLUSIONS: Albuterol improves pulmonary vascular reserve in patients with HFpEF without worsening left heart congestion. Further study is warranted to evaluate the chronic efficacy of ß-agonists in HFpEF and other forms of pulmonary hypertension. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov . Unique identifier: NCT02885636.

Novel approaches to the management of chronic systolic heart failure: future directions and unanswered questions.

Despite improvements in outcomes in the last few decades for heart failure (HF) with reduced ejection fraction (HFrEF), there still remains a need for novel therapies as many patients incompletely recover with existing therapies and progress to advanced HF. In this review, we will discuss recent advances in the management of HFrEF with a focus on upcoming therapies that hold the greatest promise for clinical use. We will discuss novel pharmacological therapies and areas of uncertainty with existing therapies. We will also discuss the potential utility and controversy surrounding novel interventions for HF such as percutaneous mitral valve repair, atrial fibrillation ablation, and other emerging interventions with positive signals for benefit in HFrEF. Finally, we will summarize the current state of stem cell and gene therapy for HFrEF and future directions.

Noninvasive evaluation of pulmonary artery pressure during exercise: the importance of right atrial hypertension.

INTRODUCTION: Identification of elevated pulmonary artery pressures during exercise has important diagnostic, prognostic and therapeutic implications. Stress echocardiography is frequently used to estimate pulmonary artery pressures during exercise testing, but data supporting this practice are limited. This study examined the accuracy of Doppler echocardiography for the estimation of pulmonary artery pressures at rest and during exercise. METHODS: Simultaneous cardiac catheterisation-echocardiographic studies were performed at rest and during exercise in 97 subjects with dyspnoea. Echocardiography-estimated pulmonary artery systolic pressure (ePASP) was calculated from the right ventricular (RV) to right atrial (RA) pressure gradient and estimated RA pressure (eRAP), and then compared with directly measured PASP and RAP. RESULTS: Estimated PASP was obtainable in 57% of subjects at rest, but feasibility decreased to 15-16% during exercise, due mainly to an inability to obtain eRAP during stress. Estimated PASP correlated well with direct PASP at rest (r=0.76, p<0.0001; bias -1 mmHg) and during exercise (r=0.76, p=0.001; bias +3 mmHg). When assuming eRAP of 10 mmHg, ePASP correlated with direct PASP (r=0.70, p<0.0001), but substantially underestimated true values (bias +9 mmHg), with the greatest underestimation among patients with severe exercise-induced pulmonary hypertension (EIPH). Estimation of eRAP during exercise from resting eRAP improved discrimination of patients with or without EIPH (area under the curve 0.81), with minimal bias (5 mmHg), but wide limits of agreement (-14-25 mmHg). CONCLUSIONS: The RV-RA pressure gradient can be estimated with reasonable accuracy during exercise when measurable. However, RA hypertension frequently develops in patients with EIPH, and the inability to noninvasively account for this leads to substantial underestimation of exercise pulmonary artery pressures.

Are existing and emerging biomarkers associated with cardiorespiratory fitness in patients with chronic heart failure?

BACKGROUND: Cardiorespiratory fitness (CRF) is closely linked to health status and clinical outcomes in heart failure (HF) patients. We aimed to test whether biomarkers can reflect CRF and its change over time. METHODS: This post hoc analysis used data from ambulatory cohorts of heart failure with reduced ejection fraction (HFrEF) (IRONOUT) and heart failure with preserved ejection fraction (HFpEF) (RELAX). Cardiopulmonary exercise testing, 6-minute walk distance (6MWD), and serum biomarkers were measured at baseline and 16- or 24-week follow-up (for IRONOUT and RELAX respectively). Biomarkers included N-terminal pro-B-type natriuretic peptide (NT-proBNP), soluble ST2, growth differentiation factor-15, and Galectin-3. RESULTS: Analysis included 225 patients with HFrEF and 216 with HFpEF. Baseline peak VO2, VE/VCO2 slope, and 6MWD showed a mild correlation with the doubling of all 4 tested biomarkers in HFrEF and HFpEF. Following multivariable adjustment (including all biomarkers), the only significant association between change in biomarker and functional parameter in HFrEF was change in NT-proBNP and change in VE/VCO2 slope (3.596% increase per doubling, 95% CI 0.779-6.492, P = .012). In HFpEF, a decrease in peak VO2 was associated with an increase in NT-proBNP (-0.726 mL/min/kg per doubling, 95% CI -1.100 to -0.353, P < .001), and a decrease in 6MWD was associated with an increase in growth differentiation factor-15 (-31.606 m per doubling, 95% CI -61.404 to -1.809, P = .038). CONCLUSIONS: In these ambulatory trial cohorts, NT-proBNP was associated with baseline and change in CRF in HFrEF and HFpEF. In contrast, novel biomarkers do not appear suitable as a reliable surrogate for serial assessment of exercise capacity in HF patients given lack of consistent independent association with CRF beyond traditional risk factors and NT-proBNP.

Characterization of the Progression From Ambulatory to Hospitalized Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Heart failure (HF) with preserved ejection fraction (HFpEF) is a heterogeneous syndrome. Some patients develop elevated filling pressures exclusively during exercise and never require hospitalization, whereas others periodically develop congestion that requires inpatient treatment. The features differentiating these cohorts are unclear. METHODS: We performed a secondary analysis of 7 National Institutes of Health-sponsored multicenter trials of HFpEF (EF ≥ 50%, N = 727). Patients were stratified by history of hospitalization because of HF, comparing patients never hospitalized (HFpEFNH) to those with a prior hospitalization (HFpEFPH). Currently hospitalized (HFpEFCH) patients were included to fill the spectrum. Clinical characteristics, cardiac structure, biomarkers, quality of life, functional capacity, activity levels, and outcomes were compared. RESULTS: As expected, HFpEFCH (n = 338) displayed the greatest severity of congestion, as assessed by N-terminal pro B-type natriuretic peptide levels, edema and orthopnea. As compared to HFpEFNH (n = 109), HFpEFPH (n = 280) displayed greater comorbidity burden, with more lung disease, renal dysfunction and anemia, along with lower activity levels (accelerometry), poorer exercise capacity (6-minute walk distance and peak exercise capacity), and more orthopnea. Patients with current or prior hospitalization displayed higher rates of future HF hospitalization, but quality of life was similarly impaired in all patients with HFpEF, regardless of hospitalization history. CONCLUSIONS: A greater burden of noncardiac organ dysfunction, sedentariness, functional impairment, and higher event rates distinguish patients with HFpEF and prior HF hospitalization from those never hospitalized. Despite lower event rates, quality of life is severely and similarly limited in patients with no history of hospitalization. These data suggest that the 2 clinical profiles of HFpEF may require different treatment strategies.

Adverse Renal Response to Decongestion in the Obese Phenotype of Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Patients with heart failure (HF) with preserved ejection fraction (HFpEF) and obesity display a number of pathophysiologic features that may render them more or less vulnerable to negative effects of decongestion on renal function, including greater right ventricular remodeling, plasma volume expansion and pericardial restraint. We aimed to contrast the renal response to decongestion in obese compared to nonobese patients with HFpEF METHODS AND RESULTS: National Institutes of Health heart failure network studies that enrolled patients with acute decompensated HFpEF (EF ≥ 50%) were included (DOSE, CARRESS, ROSE, and ATHENA). Obese HFpEF was defined as a body mass index ≥ 30 kg/m2. Compared to nonobese HFpEF (n = 118), patients with obese HFpEF (n = 214) were an average of 9 years younger (71 vs 80 years,< 0.001), were more likely to have diabetes (64% vs 31%, P< 0.001) but had less atrial fibrillation (56% vs 75%, P< 0.001). Renal dysfunction (glomerular filtration rate < 60 mL/min/1.73m2) was present in 82% of patients, and there was no difference at baseline between obese and nonobese patients. Despite similar weight loss through decongestive therapies, obese patients with HFpEF demonstrated greater rise in creatinine (Cr) and decline in glomerular filtration rate, with a 2-fold higher incidence of mild worsening renal function (rise in Cr ≥ 0.3 mg/dL) (28 vs 14%, P = 0.008) and a substantially greater increase in severe worsening of renal function (rise in Cr > 0.5 mg/dL) (9 vs 0%, P = 0.002). CONCLUSIONS: Despite being nearly a decade younger, obese patients with HFpEF experience greater deterioration in renal function during decongestion than do nonobese patients with HFpEF. Further study to elucidate the complex relationships between volume distribution, cardiorenal hemodynamics and adiposity in HFpEF is needed.

Deterioration in right ventricular structure and function over time in patients with heart failure and preserved ejection fraction.

AIMS: Prevalent right ventricular (RV) dysfunction (RVD) is associated with increased mortality in patients with heart failure with preserved ejection fraction (HFpEF), but no study has characterized long-term changes in RV structure and function within the same patient. METHODS AND RESULTS: Patients with unequivocal HFpEF defined by either invasive haemodynamics or hospitalization for pulmonary oedema (n = 271) underwent serial echocardiographic evaluations >6 months apart. Clinical, structural, functional, and haemodynamic characteristics were examined. Over a median of 4.0 years (interquartile range 2.1-6.1), there was a 10% decline in RV fractional area change and 21% increase in RV diastolic area (both P < 0.0001). These changes greatly exceeded corresponding changes in the left ventricle. The prevalence of tricuspid regurgitation increased by 45%. Of 238 patients with normal RV function at Exam 1, 55 (23%) developed RVD during follow-up. Development of RVD was associated with both prevalent and incident atrial fibrillation (AF), higher body weight, coronary disease, higher pulmonary artery and left ventricular filling pressures, and RV dilation. Patients with HFpEF developing incident RVD had nearly two-fold increased risk of death (adjusted hazard ratio 1.89, 95% confidence interval 1.01-3.44; P = 0.04). CONCLUSION: While previous attention has centred on the left ventricle in HFpEF, these data show that right ventricular structure and function deteriorate to greater extent over time when compared with changes in the left ventricle. Further study is required to evaluate whether interventions targeting modifiable risk factors identified for incident RVD, including abnormal haemodynamics, AF, coronary disease, and obesity, can prevent RVD and thus improve outcomes.

The neurohormonal basis of pulmonary hypertension in heart failure with preserved ejection fraction.

AIMS: Pulmonary hypertension (PH) represents an important phenotype among the broader spectrum of patients with heart failure with preserved ejection fraction (HFpEF), but its mechanistic basis remains unclear. We hypothesized that activation of endothelin and adrenomedullin, two counterregulatory pathways important in the pathophysiology of PH, would be greater in HFpEF patients with worsening PH, and would correlate with the severity of haemodynamic derangements and limitations in aerobic capacity and cardiopulmonary reserve. METHODS AND RESULTS: Plasma levels of C-terminal pro-endothelin-1 (CT-proET-1) and mid-regional pro-adrenomedullin (MR-proADM), central haemodynamics, echocardiography, and oxygen consumption (VO2) were measured at rest and during exercise in subjects with invasively-verified HFpEF (n = 38) and controls free of HF (n = 20) as part of a prospective study. Plasma levels of CT-proET-1 and MR-proADM were highly correlated with one another (r = 0.89, P < 0.0001), and compared to controls, subjects with HFpEF displayed higher levels of each neurohormone at rest and during exercise. C-terminal pro-endothelin-1 and MR-proADM levels were strongly correlated with mean pulmonary artery (PA) pressure (r = 0.73 and 0.65, both P < 0.0001) and pulmonary capillary wedge pressure (r = 0.67 and r = 0.62, both P < 0.0001) and inversely correlated with PA compliance (r = -0.52 and -0.43, both P < 0.001). As compared to controls, subjects with HFpEF displayed right ventricular (RV) reserve limitation, evidenced by less increases in RV s' and e' tissue velocities, during exercise. Baseline CT-proET-1 and MR-proADM levels were correlated with worse RV diastolic reserve (ΔRV e', r = -0.59 and -0.67, both P < 0.001), reduced cardiac output responses to exercise (r = -0.59 and -0.61, both P < 0.0001), and more severely impaired peak VO2 (r = -0.60 and -0.67, both P < 0.0001). CONCLUSION: Subjects with HFpEF display activation of the endothelin and adrenomedullin neurohormonal pathways, the magnitude of which is associated with pulmonary haemodynamic derangements, limitations in RV functional reserve, reduced cardiac output, and more profoundly impaired exercise capacity in HFpEF. Further study is required to evaluate for causal relationships and determine if therapies targeting these counterregulatory pathways can improve outcomes in patients with the HFpEF-PH phenotype. CLINICAL TRIAL REGISTRATION: NCT01418248; https://clinicaltrials.gov/ct2/results? term=NCT01418248&Search=Search.

The haemodynamic basis of lung congestion during exercise in heart failure with preserved ejection fraction.

AIMS: Increases in extravascular lung water (EVLW) during exercise contribute to symptoms, morbidity, and mortality in patients with heart failure and preserved ejection fraction (HFpEF), but the mechanisms leading to pulmonary congestion during exercise are not well-understood. METHODS AND RESULTS: Compensated, ambulatory patients with HFpEF (n = 61) underwent invasive haemodynamic exercise testing using high-fidelity micromanometers with simultaneous lung ultrasound, echocardiography, and expired gas analysis at rest and during submaximal exercise. The presence or absence of EVLW was determined by lung ultrasound to evaluate for sonographic B-line artefacts. An increase in EVLW during exercise was observed in 33 patients (HFpEFLW+, 54%), while 28 (46%) did not develop EVLW (HFpEFLW-). Resting left ventricular function was similar in the groups, but right ventricular (RV) dysfunction was two-fold more common in HFpEFLW+ (64 vs. 31%), with lower RV systolic velocity and RV fractional area change. As compared to HFpEFLW-, the HFpEFLW+ group displayed higher pulmonary capillary wedge pressure (PCWP), higher pulmonary artery (PA) pressures, worse RV-PA coupling, and higher right atrial (RA) pressures during exercise, with increased haemoconcentration indicating greater loss of water from the vascular space. The development of lung congestion during exercise was significantly associated with elevations in PCWP and RA pressure as well as impairments in RV-PA coupling (area under the curve values 0.76-0.84). CONCLUSION: Over half of stable outpatients with HFpEF develop increases in interstitial lung water, even during submaximal exercise. The acute development of lung congestion is correlated with increases in pulmonary capillary hydrostatic pressure that favours fluid filtration, and systemic venous hypertension due to altered RV-PA coupling, which may interfere with fluid clearance. CLINICAL TRIAL REGISTRATION: NCT02885636.