Borlaug, Barry A.

Abstract Background Patient-worn accelerometer is increasingly used in patients with heart failure and reduced ejection fraction (HFrEF) to assess daily activity and and as surrogate endpoint. We examined the association between cardiac physiology and daily activity by patient-worn accelerometer recordings in stable HFrEF patients. Methods In this descriptive study, physical average daily accelerometer units (PADA) and total average daily accelerometer unit (TADA) were assessed by a accelerometer recordings. Sixty three stable ambulatory patients with HFrEF, mainly men (92%), mean age 58±10 years, and ejection-fraction 26±4% underwent hemodynamic exercise testing, and accelerometry (Table 1). Patients were divided by PADA in a low and high activity level groups based on counts per minute physical activity. Results Patients in the low activity group were older and more frequently treated with diuretics. At rest, the low activity group was characterized by a lower cardiac index (CI) (2.2±0.4 vs. 2.4±0.4 l/min/m2, p=0.01), Stroke volume (SV) (70±19 vs. 81±17 ml, p=0.02) but not pulmonary capillary wedge pressure (PCWP) (12±5 vs. 11±5 mmHg, p=0.3) (Figure 1). Low activity group reached a lower CI (4.8±1.7 vs. 6.6±1.7 l/min/m2, p<0.001) and SV (94±32 vs. 121±29 ml, p<0.001), but not in PCWP (31±12 vs. 27±8 mmHg, p=0.2) or arterial-venous O2 content difference (A-VO2 diff) (13.00±2.32 vs. 12.96±1.65 ml O2/dl, p=0.9) at peak exercise. The attenuated increase was associated with attenuated increase in SV rther than increase in heart rate (42±23 vs. 52±21 bpm, p=0.07). Finally, CI at peak exercise was the only independent variable associated with PADA after adjusting for age, gender, and BMI (p<0.0001). The PADA and TADA were associated to functional assessments using Kansas City Cardiomyopathy Questionnaire, but not with New York Heart Association class or N-terminal pro brain natriuretic peptide (NT-proBNP) (Table 1). Conclusion Accelerometer-assessed activity in patients with HFrEF are associated with impairments in LV performance, SV reserve and cardiac output during exercise, to a greater extent than changes in arterial-venous O2 content difference or pulmonary vascular pressures. Accelerometer data may provide information about the functional status that we do not nessecary find in the widely used tools in both research and daily clinical practice. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): This work was supported by the Danish Heart Foundation [grant numbers 17-R116-A7714-22076, 18-R124-A8573-22107]; Steno Diabetes Center Odense, Denmark [grant number 3363] and A.P. Møller Foundation for the Advancement of Medical Science [grant number 17-L-0339]. Table 1. Baseline and regression analysisFigure 1. Change in PCWP and CI by exercise

Abstract Background Atrial fibrillation (AF) is common in patients with heart failure and preserved ejection fraction (HFpEF) and associated with left atrial (LA) myopathy, reduced exercise capacity and poor outcomes. However, the mechanisms underlying exercise intolerance in HFpEF with AF are not well-characterized. Purpose To test hypotheses that patients with HFpEF and AF (HFpEF-AF) would display greater acute impairments in right heart-pulmonary vascular coupling during exercise, leading to greater elevations in left and right heart filling pressures and increased lung congestion as compared to patients with HFpEF and no AF (HFpEF-no-AF) and control subjects free of heart failure and AF. As corollary hypotheses, we also posited that these changes would lead to greater ventricular interdependence during exercise in HFpEF-AF, and that pulmonary hypertension in HFpEF-AF was not simply ascribable to the LA dysfunction that accompanies AF, which would provide greater impetus to pursue restoration of sinus rhythm. Methods Subjects with HFpEF-AF (n=35), HFpEF-no-AF (n=85), and controls free of heart failure or AF (n=28) underwent cardiopulmonary exercise testing with invasive hemodynamic assessment and simultaneous echocardiography and lung ultrasound in a prospective study. Results As compared with controls and HFpEF-no-AF, subjects with HFpEF-AF displayed poorer left ventricular (LV) longitudinal strain, lower LA reservoir strain with greater LA volume at rest. With exercise, subjects with HFpEF-AF displayed more severe exercise-induced pulmonary hypertension, higher right atrial pressure (RAP) and more pronounced right ventricular-pulmonary vascular uncoupling. Peak oxygen consumption was lowest in patients with HFpEF-AF, coupled with greater limitations in cardiac output reserve and more severe increases in lung congestion and pulmonary vascular resistance (Figure 1). Dynamic ventricular interaction was greatest in HFpEF-AF, evidenced by greater increases in LV eccentricity index and RAP/PCWP (Figure 2) and less increase in LV transmural pressure compared with HFpEF-no-AF. In a sensitivity analysis, patients with HFpEF-AF displayed more severe pulmonary hypertension and pulmonary vascular disease compared to HFpEF-no-AF even after matching for the severity of LA remodeling and dysfunction. Conclusions Patients with AF and HFpEF display more severe abnormalities in pulmonary vascular reserve with exercise leading to greater lung congestion and enhanced exertional ventricular interdependence compared to patients with HFpEF-no-AF. While many of these differences appear attributable to LA dysfunction, the presence of AF is associated with more severe pulmonary vascular disease independent of LA myopathy, suggesting potential benefit from restoration of sinus rhythm even in the setting of LA myopathy. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): R01 HL128526

Objective Mild aortic valve stenosis (AS) and aortic valve (AV) sclerosis are associated with diastolic dysfunction and increased mortality in the general population. This study specifically investigated the impact of mild AV disease in heart failure with preserved ejection fraction (HFpEF). Methods Consecutive patients hospitalised with HFpEF (n=370) underwent assessment of cardiac structure and function and long-term clinical follow-up. Results In the study cohort, 111 had mild AS (30%), 104 AV sclerosis (28%) and 155 a non-calcified AV (42%). Mild-to-moderate AV regurgitation (AR) was present in 64 (17%). Compared with patients with a normal AV, those with AV disease were older, with worse renal function and more atrial fibrillation. E/e′ increased from non-calcified AV to AV sclerosis to mild AS (13.8 (10.8–16.8) vs 15.0 (10.9–20.0) vs 18.0 (12.7–23.3), respectively; p<0.001)). Left ventricular diastolic pressure–volume relationships were shifted leftwards in patients with AS and AV sclerosis, but not influenced by AR. The left ventricular end-diastolic volume normalised at 20 mm Hg was 117±34 mL, 106±30 mL and 112±30 mL in non-calcified AV, AV sclerosis and mild AS, respectively (p=0.023), while 112±32 mL in mild-to-moderate AR. Over 30 months (IQR, 8–61 months), 247 patients died (67%). The presence of mild AV disease was associated with increased mortality, but this was no longer significant after adjusting for age and sex. Conclusions Low-grade AV disease is common among patients hospitalised for HFpEF and is associated with older age, atrial arrhythmia, renal dysfunction, higher left heart filling pressures and increased left ventricular chamber stiffness.

Abstract Aims We evaluated the impact of echocardiographic epicardial adipose tissue (EAT) on cardiovascular haemodynamics, metabolic profile and prognosis in heart failure (HF) using combined cardiopulmonary‐echocardiography exercise stress. Methods and results We analysed EAT thickness of HF patients with reduced (HFrEF, n = 205) and preserved (HFpEF, n = 188) ejection fraction, including 44 controls. HFpEF patients displayed the highest EAT, while HFrEF patients had lower values than controls. EAT showed an inverse correlation with natriuretic peptides, troponin T and C‐reactive protein in HFrEF, while having a direct association with troponin T and C‐reactive protein in HFpEF. EAT was independently associated with peak oxygen consumption (VO 2 ) and peripheral extraction (AVO 2 diff), regardless of body mass index. EAT was inversely correlated with peak VO 2 and AVO 2 diff in HFpEF, while a direct association was observed in HFrEF, where lower EAT values were associated with worse left ventricular systolic dysfunction. In HFpEF, increased EAT was related to right ventriculo–arterial (tricuspid annular plane systolic excursion/systolic pulmonary artery pressure) uncoupling. After 21 months of follow‐up, 146 HF hospitalizations and 34 cardiovascular deaths were recorded in the HF population. Cox multivariable analysis supported an independent differential role of EAT in HF cohorts (interaction P = 0.01): higher risk of adverse events for increasing EAT in HFpEF [hazard ratio (HR) 1.12, 95% confidence interval (CI) 1.04–1.37] and for decreasing EAT in HFrEF (HR 0.75, 95% CI 0.54–0.91). Conclusion In HFpEF, EAT accumulation is associated with worse haemodynamic and metabolic profile, also affecting survival. Conversely, lower EAT values imply higher left ventricular dysfunction, global functional impairment and adverse prognosis in HFrEF.

Abstract Aims We aimed to determine the effect of increasing body weight upon right ventricular (RV) volumes, energetics, systolic function, and stress responses using cardiovascular magnetic resonance (CMR). Methods and results We first determined the effects of World Health Organization class III obesity [body mass index (BMI) &gt; 40 kg/m2, n = 54] vs. healthy weight (BMI &lt; 25 kg/m2, n = 49) upon RV volumes, energetics and systolic function using CMR. In less severe obesity (BMI 35 ± 5 kg/m2, n = 18) and healthy weight controls (BMI 21 ± 1 kg/m2, n = 9), we next performed CMR before and during dobutamine to evaluate RV stress response. A subgroup undergoing bariatric surgery (n = 37) were rescanned at median 1 year to determine the effects of weight loss. When compared with healthy weight, class III obesity was associated with adverse RV remodelling (17% RV end-diastolic volume increase, P &lt; 0.0001), impaired cardiac energetics (19% phosphocreatine to adenosine triphosphate ratio reduction, P &lt; 0.001), and reduction in RV ejection fraction (by 3%, P = 0.01), which was related to impaired energetics (R = 0.3, P = 0.04). Participants with less severe obesity had impaired RV diastolic filling at rest and blunted RV systolic and diastolic responses to dobutamine compared with healthy weight. Surgical weight loss (34 ± 15 kg weight loss) was associated with improvement in RV end-diastolic volume (by 8%, P = 0.006) and systolic function (by 2%, P = 0.03). Conclusion Increasing body weight is associated with significant alterations in RV volumes, energetic, systolic function, and stress responses. Adverse RV modelling is mitigated with weight loss. Randomized trials are needed to determine whether intentional weight loss improves symptoms and outcomes in patients with obesity and heart failure.

Approximately half of all patients with heart failure (HF) have a preserved ejection fraction, and the prevalence is growing rapidly given the aging population in many countries and the rising prevalence of obesity, diabetes, and hypertension. Functional capacity and quality of life are severely impaired in heart failure with preserved ejection fraction (HFpEF), and morbidity and mortality are high. In striking contrast to HF with reduced ejection fraction, there are few effective treatments currently identified for HFpEF, and these are limited to decongestion by diuretics, promotion of a healthy active lifestyle, and management of comorbidities. Improved phenotyping of subgroups within the overall HFpEF population might enhance individualization of treatment. This review focuses on the current understanding of the pathophysiologic mechanisms underlying HFpEF and treatment strategies for this complex syndrome.

Background Hemodynamic perturbations in heart failure with preserved ejection fraction (HFpEF) may alter the distribution of blood in the lungs, impair gas transfer from the alveoli into the pulmonary capillaries, and reduce lung diffusing capacity. We hypothesized that impairments in lung diffusing capacity for carbon monoxide (DL CO ) in HFpEF would be associated with high mean pulmonary capillary wedge pressures during exercise. Methods and Results Rebreathe DL CO and invasive hemodynamics were measured simultaneously during exercise in patients with exertional dyspnea. Pulmonary pressure waveforms and breath‐by‐breath pulmonary gas exchange were recorded at rest, 20 W, and symptom‐limited maximal exercise. Patients with HFpEF (n=20; 15 women, aged 65±11 years, body mass index 36±8 kg/m 2 ) achieved a lower symptom‐limited maximal workload (52±27 W versus 106±42 W) compared with controls with noncardiac dyspnea (n=10; 7 women, aged 55±10 years, body mass index 30±5 kg/m 2 ). DL CO was lower in patients with HFpEF compared with controls at rest (DL CO 10.4±2.9 mL/min per mm Hg versus 16.4±6.9 mL/min per mm Hg, P <0.01) and symptom‐limited maximal exercise (DL CO 14.6±4.7 mL/min per mm Hg versus 23.8±10.8 mL/min per mm Hg, P <0.01) because of a lower alveolar‐capillary membrane conductance in HFpEF (rest 16.8±6.6 mL/min per mm Hg versus 28.4±11.8 mL/min per mm Hg, P <0.01; symptom‐limited maximal exercise 25.0±6.7 mL/min per mm Hg versus 45.5±22.2 mL/min per mm Hg, P <0.01). DL CO was lower in HFpEF for a given mean pulmonary artery pressure, mean pulmonary capillary wedge pressure, pulmonary arterial compliance, and transpulmonary gradient. Conclusions Lung diffusing capacity is lower at rest and during exercise in HFpEF due to impaired gas conductance across the alveolar‐capillary membrane. DL CO is impaired for a given pulmonary capillary wedge pressure and pulmonary arterial compliance. These data provide new insight into the complex relationships between hemodynamic perturbations and gas exchange abnormalities in HFpEF.