Frederiksen, Peter

BACKGROUND: Guidelines acknowledge that discordant low-gradient (LG) aortic stenosis (AS) may be severe, but verifying this can be challenging. Right heart catheterization during exercise is considered the gold standard for evaluating ventricular hemodynamics. No invasive studies have compared the hemodynamic response of discordant LG and severe AS during exercise. The aim of this observational study was to describe exercise hemodynamics in patients with asymptomatic discordant AS and left ventricular ejection fraction ≥50%. METHODS: Patients with aortic valve area ≤1.5 cm 2 underwent right heart catheterization at rest and during maximal exercise, measuring pulmonary capillary wedge pressure (PCWP), cardiac output (CO), and the PCWP/CO-slope. Patients were stratified into 3 groups: discordant LG AS (aortic valve area ≤1.0 cm 2 and mean gradient <40 mm Hg); moderate AS (aortic valve area >1.0 cm 2 ); and high-gradient (HG) severe AS (aortic valve area ≤1.0 cm 2 and mean gradient ≥40 mm Hg). RESULTS: Among 86 patients, 17 (20%) had discordant LG, 49 (57%) moderate, and 20 (23%) HG severe AS. The median PCWP/CO-slope was significantly steeper in discordant LG (3.3 [interquartile range, 2.1–4.3] mm Hg/L/min) and HG severe AS (2.7 [1.9–3.4] mm Hg/L per minute) compared with moderate AS (1.9 [0.7–2.8] mm Hg/L per minute), P =0.004. In a regression model adjusted for age, sex, and rest PCWP, systemic arterial compliance and AS severity were significantly associated with the PCWP/CO-slope. Furthermore, patients with discordant LG AS had a leftward-upward shift in the PCWP/CO-curve. CONCLUSIONS: Discordant LG and HG severe AS had similar hemodynamic responses to exercise with steeper PCWP/CO-slope than in moderate AS, suggesting that discordant LG AS is a severe form of AS. In addition, the left upwards shift in PCWP/CO-curve for discordant LG compared with HG severe AS indicates that this group also has heart failure with preserved ejection fraction physiology. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04913870 and NCT02395107.

Abstract Introduction To investigate the effect of empagliflozin on right ventricular (RV) function in patients with heart failure with reduced ejection fraction (HFrEF). Sodium-glucose cotransporter-2 (SGLT2) inhibitors improve outcomes and reverse left ventricular (LV) remodelling in HFrEF. The impact on RV function remains uncertain. Methods The Empire HF trial was an investigator-initiated, double-blind, randomized, placebo-controlled trial of 190 participants with a left ventricular ejection fraction (LVEF) of 40% or lower, with New York Heart Association (NYHA) Class I−III symptoms. Participants were randomized to receive either empagliflozin (at a dose of 10 mg once daily) or placebo, on top of recommended therapy for 12 weeks. The primary endpoint of this exploratory substudy was changes in RV free wall strain (RVFWS) across the whole cohort. RVFWS was also stratified into tertiles based on baseline RVFWS. Secondary endpoints included changes in tricuspid annular plane systolic excursion (TAPSE) and RV S’ velocity. Results Between June 2017 and September 2019, a total of 190 patients were enrolled, of whom 160 were included in this substudy. Baseline characteristics were balanced between the groups (mean age of 64 ± 11 years, 86% male, mean LVEF: 29 ± 8%, 79% in NYHA Class II, 83 patients (52%) had an implanted cardiac device, and tricuspid valve regurgitation was absent/trace in 136 (85%) and mild in 24 (15%)). A high proportion of the population were on optimal medical treatment for HFrEF, and device therapy remained unchanged during follow-up. The overall mean RVFWS was −16.7 ± 6.1%, with the empagliflozin group at −16.4 ± 6.2% and the placebo group at −16.9 ± 5.9%. No differences were observed in RVFWS between the groups. When stratified by baseline RVFWS into tertiles, patients in the lowest tertile demonstrated a significant improvement with empagliflozin (treatment effect: −2.9% [95% CI: −5.0 to −0.3]; P = .027). This finding was independent of LVEF, plasma volume, and weight loss, and remained unchanged after additional adjustment for LV remodelling and the presence of resynchronization therapy. No significant treatment effect was observed in the middle or highest tertiles of RVFWS, nor in the overall or lowest tertiles of TAPSE or RV S’. Conclusion This exploratory substudy of the Empire HF, treatment with empagliflozin exerted no overall effect on RV function in stable HFrEF patients, but significantly improved RVFWS in patients in the lowest tertile of RVFWS after 12 weeks of treatment. Trial Registration ClinicalTrials.gov, Unique Identifier: NCT03198585

Abstract Background Guidelines acknowledge that discordant low-gradient (LG) aortic stenosis (AS) may be severe, but verifying this can be challenging. Right heart catheterization during exercise is considered the gold standard evaluating ventricular hemodynamics. No invasive studies have compared the hemodynamic response of discordant LG and severe AS during exercise. Purpose To describe exercise hemodynamics in patients with asymptomatic discordant AS and left ventricular ejection fraction ≥50%, and to identify the variables associated with the steepness of the pulmonary capillary wedge pressure (PCWP)/cardiac output (CO) slope defined as (peak exercise PCWP-rest PCWP)/(peak exercise CO-rest CO). Methods Patients with aortic valve area (AVA) ≤1.5 cm² underwent right heart catheterization at rest and during maximal exercise measuring pulmonary artery pressures, PCWP, CO and PCWP/CO slope. Patients were stratified in three groups: 1) discordant LG AS (AVA ≤1.0 cm² and mean gradient &lt;40 mmHg); 2) moderate AS (AVA &gt;1.0 cm²) and 3) high-gradient severe AS (AVA ≤1.0 cm² and mean gradient ≥40 mmHg). Results Among 86 patients, 17 (20%) had discordant LG, 49 (57%) moderate, and 20 (23%) high-gradient severe AS. The PCWP/CO slope was significantly steeper in discordant LG: median 3.3 mmHg/L/min (interquartile range: 2.2 mmHg/L/min) and high-gradient severe AS: 2.7 mmHg/L/min (1.5 mmHg/L/min) compared to moderate AS: 1.9 mmHg/L/min (2.0 mmHg/L/min), p=0.004. In a linear regression model adjusted for age, sex and rest PCWP, systemic arterial compliance and AS severity were significantly associated with the PCWP/CO slope. Furthermore, patients with discordant LG AS had a leftward and upward shift in the PCWP/CO slope. Conclusions Discordant LG and high-gradient severe AS had similar hemodynamic response to exercise with steeper PCWP/CO slope than in moderate AS, suggesting that discordant LG AS is a severe form of AS. In addition, the left-upward shift in PCWP/CO slope for discordant LG compared to high-gradient severe AS indicates that, this group also has latent heart failure with preserved ejection fraction physiology.

Background Haemodynamic exercise testing is important for evaluating patients with dyspnoea on exertion and preserved ejection fraction. Despite very different pathologies, patients with pressure (aortic stenosis (AS)) and volume (mitral regurgitation (MR)) overload and diastolic dysfunction after recent acute myocardial infarction (AMI) reach similar filling pressure levels with exercise. The pressure–flow relationships (the association between change in cardiac output (∆CO) and change in pulmonary arterial wedge pressure (∆PAWP) may provide insight into haemodynamic adaptation to exercise in these groups. Methods and results One hundred sixty-eight subjects aged >50 years with a left ventricular ejection fraction of ≥50% underwent invasive exercise testing. They were enrolled in four different studies: AS (40 patients), AMI (52 patients), MR (43 patients) and 33 healthy subjects. Haemodynamic data were measured at rest, at 25 W, 75 W and at peak exercise. In all groups, PAWP increased with exercise. The greatest increase was observed in patients with AMI (from 12.7±3.9 mm Hg to 33.1±8.2 mm Hg, p<0.0001) and patients with AS (from 11.8±3.9 mm Hg to 31.4±6.1 mm Hg, p<0.0001), and the smallest was observed in healthy subjects (from 8.3±2.4 mm Hg to 21.1±7.5 mm Hg, p<0.0001). In all groups, the relative pressure increase was greatest at the beginning of the exercise. CO increased most in healthy patients (from 5.3±1.1 to 16.0±3.0 L/min, p<0.0001) and least in patients with AS (from 5.3±1.2 L/min to 12.4±2.6 L/min, p<0.0001). The pressure–flow relationships (∆PAWP/∆CO) and differed among groups (p = 0.02). In all groups, the pressure–flow relationship was steepest in the initial phase of the exercise test. The AMI and AS groups (2.3±1.2 mm Hg/L/min and 3.0±1.3 mm Hg/L/min, AMI and AS, respectively) had the largest overall pressure–flow relationship; the healthy group had the smallest initially and at peak exercise (1.3±1.1 mm Hg/L/min) followed by MR group (1.9±1.4 mm Hg/L/min). Conclusion The pressure–flow relationship was steepest in the initial phase of the exercise test in all groups. The pressure–flow relationship differs between groups. Trial registration numbers NCT01974557 , NCT01046838 , NCT02961647 and NCT02395107 .

Background: The relationship between blood volume and pressure in the vascular system can be described in terms of unstressed and stressed blood volume. Stressed blood volume determines venous pressure and provides preload back to the heart, which regulates the generation of cardiac output (CO) via the Frank-starling mechanism. Whether sodium-glucose cotransporter-2 (SGLT2i) favorably modifies stressed blood volume is not known. Hypothesis: To investigate the effect of SGLT2i (empagliflozin) on the hemodynamic estimated stressed blood volume (eSBV) in HFrEF patients compared to placebo. Methods: A post hoc analysis of investigator-initiated, double-blinded, placebo-controlled, randomized trial. Seventy patients were assigned to empagliflozin of 10 mg or matching placebo once daily for 12 weeks. Patients underwent right heart catheterization at rest and during exercise at baseline and follow-up. Outcome was change in eSBV after 12 weeks of empagliflozin treatment at each level of exercise. We conducted computer-modelling simulations based on invasive hemodynamic assessment to measure eSBV. Results: HFrEF patients with mean age was 57 years, mean ejection fraction 27%, 47 (71%) on diuretics were randomized. After 12 weeks treatment exercise eSBV was significantly reduced at 0 watt, 25 watt and 25 % of maximal exercise watt, compared to placebo [(0 watt; –258 mL, 95% CI –476 to –39, p=0.021); (25 watt; –301 mL, 95% CI –561 to –40, p=0.024); and (25% of peak exercise watt; –262 mL, 95% CI –490 to –34, p=0.024)]. There was no effect on rest, or at peak exercise eSBV [(Rest; –75 ml, 95% confidence interval [CI] –279 to 130; p=0.47); and (Peak; –96 mL, 95% CI –444 to 251, p=0.59)]. This was consistent among patients with and without type 2 diabetes, etiology of HFrEF, and diuretic usage (Figure 1). Conclusion: Empagliflozin may contribute to shift blood from the effective circulatory beds to the venous reservoir in reducing filling pressure and eSBV, but maintaining CO.

Background: Stressed blood volume (SBV) is a major determinant of systemic and pulmonary venous pressures which, in turn, determine left and right ventricular fillings and regulates cardiac output via the Frank-Starling mechanism. It is not known whether inhibition of the SGLT2 (sodium–glucose cotransporter-2) favorably affects SBV. We investigated the effect of empagliflozin on estimated SBV in patients with heart failure and reduced ejection fraction compared with placebo. Methods: This was a post hoc analysis of an investigator-initiated, double-blinded, placebo-controlled, randomized trial. Seventy patients were assigned to empagliflozin 10 mg or matching placebo once daily for 12 weeks. Patients underwent right heart catheterization at rest and during exercise at baseline and follow-up. The outcome was change in estimated SBV after 12 weeks of empagliflozin treatment over the full range of exercise, determined using a recently introduced analytical approach based on invasive hemodynamic assessment. Results: Patients with heart failure and reduced ejection fraction, mean age, 57 years and mean ejection fraction 27%, with 47 patients (71%) receiving diuretics were randomized. The effect of empagliflozin on estimated SBV over the full range of exercise loads showed a statistically significant reduction compared with placebo (−198.4 mL [95% CI, −317.4 to −79.3] P =0.001), a 9% decrease. The decrease in estimated SBV by empagliflozin was significantly correlated with the decrease in PCWP ( R =−0.33, P <0.0001). The effect of empagliflozin was consistent across subgroup analysis. Conclusions: Empagliflozin treatment significantly reduced SBV compared with placebo after 12 weeks of treatment in patients with stable chronic heart failure and reduced ejection fraction during sub maximal exercise. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03198585.

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&lt;0.001) and SV (94±32 vs. 121±29 ml, p&lt;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&lt;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