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.
Effects of empagliflozin on right ventricular free-wall strain in patients with heart failure and reduced ejection fraction: results from the Empire HF Trial
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 Aims In aortic stenosis (AS), estimation of left ventricular (LV) contractility is difficult as most markers of systolic LV function are load-dependent. The ratio of LV ejection fraction (LVEF) to end-systolic wall stress (ESWS), has been widely accepted as a marker of contractility. However, no studies have evaluated if this ratio is affected by loading conditions. The study describes changes in ESWS and ESWS corrected LVEF after transcatheter aortic valve replacement (TAVR). Methods and results In this prospective study, 41 patients with severe AS underwent echocardiography, LV catheterisation, and computed tomography (CT) before and immediately after TAVR. ESWS was estimated from echocardiography alone (ESWSEcho), combining CT LV dimensions and echocardiographic gradients (ESWSCT + echo) and combining CT LV dimensions and invasively measured LV end-systolic pressure (ESWSCT + Invasive). ESWSecho, ESWSCT + echo and ESWSCT + Invasive all decreased significantly after TAVR (89 ± 48 vs. 57 ± 37 Kdynes/cm2, P < 0.01; 69 ± 8 vs. 51 ± 8 Kdynes/cm2, P < 0.01, and 197 ± 69 vs. 137 ± 48 Kpa/cm2, P < 0.01, respectively). We observed weak to moderate associations between the methods. After TAVR, LVEF corrected to ESWSecho, ESWSCT + echo and ESWSCT + Invasive increased (0.93 ± 0.07 vs. 1.91 ± 2.1, P = 0.013; 0.36 ± 0.19 vs. 0.58 ± 0.33, P < 0.01, and 0.3 ± 0.02 vs. 2.5 ± 1.5, P < 0.01, respectively). Conclusion ESWSecho, ESWSCT + echo and ESWSCT + Invasive decreased significantly after TAVR suggesting they reflect afterload, but independent of method, ESWS corrected LVEF increased slightly post-TAVR, indicating load dependency.
Impact of valvulo-vascular haemodynamics on left ventricular remodelling and the prevalence of discordant moderate aortic stenosis
Abstract Aims This study aims to describe the prevalence of discordant mild/moderate aortic stenosis (AS) in a population-based study and to identify the mechanisms that lead to reduced stroke volume (SV) and discordant moderate AS. Methods and results Discordant high-gradient (HG)-mild AS, defined as AVA > 1.5 cm2 and mean pressure gradient (MG) of 20–40 mmHg, and discordant low-gradient (LG) moderate AS, defined as AVA 1.0–1.5 cm2 and MG < 20 mmHg, were assessed in 883 individuals from the DANCAVAS screening study with aortic valve calcification and 257 individuals form the PROGRESSA study excluding those with left ventricular (LV) ejection fraction < 50%. In the DANCAVAS cohort, 150 men had mild/moderate AS of which 34% had discordance between MG and AVA, representing 66% with moderate AS. Among 262 patients in the combined cohort, 39% had discordant LG-moderate AS and 6% discordant HG-mild AS. Compared with concordant mild and moderate AS, individuals with discordant LG-moderate AS were more likely to present with LV concentric remodelling geometry (26 vs. 33 vs. 45%, P < 0.001), increased valvulo-arterial impedance (3.3 ± 0.7 vs. 3.6 ± 0.5 vs. 4.1 ± 0.7 mmHg/mL/m2, P < 0.001), and reduced systemic arterial compliance (SAC) (0.74 ± 0.22 vs. 0.81 ± 0.22 vs. 0.64 ± 0.18 mL/m2/mmHg, P < 0.001). Factors associated with SV index were relative wall thickness, LV end-diastolic diameter index, SAC, and LV remodelling pattern. Conclusion Discordant moderate AS is common, accounting for two-thirds of patients with moderate AS in the general male population. Patients with discordant LG-moderate AS have predominantly a concentric remodelling pattern with reduced SV. Reduced SV index was associated with signs of reduced vascular compliance, suggesting that altered vascular properties drive differences in remodelling patterns and discordant moderate AS.
Assessment of diastolic function in aortic stenosis: A comparison between 2009 and 2016 guidelines
AbstractAimsNew diastolic dysfunction (DD) guidelines were introduced in 2016 to replace the 2009 guidelines, but have not yet been evaluated in aortic stenosis (AS). We aimed to compare the 2009 and 2016 DD guidelines in severe AS patients in terms of association with left ventricular (LV) and left atrial (LA) remodeling, with pulmonary capillary wedge pressure (PCWP) at rest and exercise, and with prognosis.Methods and resultsWe included 212 patients with severe AS (112 undergoing AVR, 100 asymptomatic). Echocardiography, magnetic resonance imaging, and brain natriuretic peptides (BNP) were performed/measured. Thirty‐nine asymptomatic patients had PCWP measured during rest and maximal exertion. Asymptomatic patients were followed for 3.1 years for the combined endpoint of death, AVR or admission with heart failure. The 2009 and 2016 DD guidelines agreed poorly with each other (Cohens’ κ = .15). 2009 guidelines showed many ambiguous DD findings. With the 2016 guidelines, 20% of patients had indeterminate DD. DD grade 2 according to 2016 guidelines showed stronger association with symptom status, BNP, global longitudinal strain (GLS) and peak exercise PCWP than 2009 guidelines. For indeterminate DD patients according to 2009 guidelines, GLS above the median was associated with event‐free survival (HR .11 (95% CI .02–.53)). For neither guideline was DD associated with the combined endpoint in asymptomatic patients.ConclusionThe 2016 guidelines show a stronger association with BNP, GLS, and exercise PCWP than the 2009 guidelines. The 2016 guidelines result in 20% of patients with indeterminate DD; however, these patients may possibly be stratified according to GLS.
First-phase ejection fraction: association with remodelling and outcome in aortic valve stenosis
Background First-phase ejection fraction (EF1), the left ventricular (LV) ejection fraction (EF) until the time of peak transaortic velocity, is a novel marker of subclinical LV dysfunction able to predict adverse events in aortic stenosis (AS). This study investigated the association between end-systolic wall stress (ESWS) and EF1 in severe AS, as well as the prognostic value of EF1 in severe asymptomatic AS. Methods Two prospectively gathered cohorts of 94 asymptomatic patients and 108 symptomatic patients scheduled for aortic valve replacement (AVR), all with severe AS (aortic valve area <1 cm2) were stratified according to the median value of EF1 (33%). EF1 was defined as the EF at peak transaortic velocity. Asymptomatic patients were followed up for 3 years for the combined end-point of death, AVR or admission with heart failure. Results EF1 correlated with EF and was inversely associated with ESWS. In multivariate regression analysis, ESWS (p<0.001) and replacement fibrosis measured by MRI (p=0.02) were associated with EF1. Among asymptomatic patients, EF1 above the median was associated with the combined primary endpoint (HR=0.53 (95% CI 0.33 to 0.87)), while global longitudinal strain and EF were not. Among 42 patients with discordant AS (mean gradient <40 mm Hg), EF1 above median was associated with the primary endpoint (HR 0.28 (95% CI 0.12 to 0.61)). Conclusion EF1 is an afterload-dependent measure that is associated with events in patients with asymptomatic severe AS. The afterload dependency of EF1 may be useful in timing of risk stratification in patients with discordant AS. Trial registration numbers NCT02395107 and NCT02316587.