Echocardiographic predictors of exercise intolerance in patients with heart failure with severely reduced ejection fraction

Right Ventricular to Pulmonary Artery Uncoupling Is Associated With Impaired Exercise Capacity in Patients With Transthyretin Cardiac Amyloidosis

BACKGROUND

Exercise capacity is related to mortality and morbidity in heart failure (HF) patients. Determinants of exercise capacity in transthyretin cardiac amyloidosis (ATTR-CA) have not been established.

METHODS AND RESULTS

This single-center study retrospectively evaluated ATTR-CA patients and patients with non-amyloidosis HF with preserved/mildly reduced ejection fraction (HFpEF/HFmrEF) (n=32 and n=51, respectively). In the ATTR-CA group, the median age was 75.5 years (interquartile range [IQR] 71.3-78.8 years), 90.6% were male, and the median left ventricular (LV) ejection fraction was 53.5% (IQR 41.4-65.6%). Cardiopulmonary exercise tests revealed a median peak oxygen consumption and anaerobic threshold of 15.9 (IQR 11.6-17.4) and 10.6 (IQR 8.5-12.0] mL/min/kg, respectively, and ventilatory efficiency (minute ventilation/carbon dioxide production [V̇E/V̇CO2] slope) of 35.5 (IQR 32.0-42.5). Among exercise variables, V̇E/V̇CO2slope has the greatest prognostic value. Univariate analysis revealed a significant correlation between V̇E/V̇CO2slope and age, LV global longitudinal strain, tricuspid annular plain systolic excursion/pulmonary arterial systolic pressure (TAPSE/PASP) ratio, and mixed venous oxygen saturation. In multivariate analyses, the TAPSE/PASP ratio was an independent predictor of V̇E/V̇CO2slope (95% confidence interval -44.5, -10.8; P=0.0067). In non-amyloidosis HFpEF/HFmrEF patients, the TAPSE/PASP ratio was not independently correlated with V̇E/V̇CO2slope.

CONCLUSIONS

Right ventricular-pulmonary artery coupling estimated by the TAPSE/PASP ratio determines exercise capacity in ATTR-CA patients. This highlights the importance of early therapeutic intervention against underappreciated right ventricular dysfunction associated with ATTR-CA.

Hemodynamic Changes During Physiological and Pharmacological Stress Testing in Patients With Heart Failure: A Systematic Review and Meta-Analysis

Although disease etiologies differ, heart failure patients with preserved and reduced ejection fraction (HFpEF and HFrEF, respectively) both present with clinical symptoms when under stress and impaired exercise capacity. The extent to which the adaptation of heart rate (HR), stroke volume (SV), and cardiac output (CO) under stress conditions is altered can be quantified by stress testing in conjunction with imaging methods and may help to detect the diminishment in a patient’s condition early. The aim of this meta-analysis was to quantify hemodynamic changes during physiological and pharmacological stress testing in patients with HF. A systematic literature search (PROSPERO 2020:CRD42020161212) in MEDLINE was conducted to assess hemodynamic changes under dynamic and pharmacological stress testing at different stress intensities in HFpEF and HFrEF patients. Pooled mean changes were estimated using a random effects model. Altogether, 140 study arms with 7,248 exercise tests were analyzed. High-intensity dynamic stress testing represented 73% of these data (70 study arms with 5,318 exercise tests), where: HR increased by 45.69 bpm (95% CI 44.51–46.88; I2 = 98.4%), SV by 13.49 ml (95% CI 6.87–20.10; I2 = 68.5%), and CO by 3.41 L/min (95% CI 2.86–3.95; I2 = 86.3%). No significant differences between HFrEF and HFpEF groups were found. Despite the limited availability of comparative studies, these reference values can help to estimate the expected hemodynamic responses in patients with HF. No differences in chronotropic reactions, changes in SV, or CO were found between HFrEF and HFpEF. When compared to healthy individuals, exercise tolerance, as well as associated HR and CO changes under moderate-high dynamic stress, was substantially impaired in both HF groups. This may contribute to a better disease understanding, future study planning, and patient-specific predictive models.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42020161212].

Right ventricular function and its coupling to pulmonary circulation predicts exercise tolerance in systolic heart failure

Aims

Right ventricular (RV) dysfunction, pulmonary hypertension, and exercise intolerance have prognostic values, but their interrelation is not fully understood. We investigated how RV function alone and its coupling with pulmonary circulation (RV‐PA) predict cardio‐respiratory fitness in patients with heart failure and reduced ejection fraction (HFrEF).

Methods and results

The Evaluation of Resynchronization Therapy for Heart Failure (EARTH) study included 205 HFrEF patients with narrow (n = 85) and prolonged (n = 120) QRS duration undergoing implantable cardioverter defibrillator implantation. All patients underwent a comprehensive evaluation with exercise tolerance tests and echocardiography. We investigated the correlations at baseline between RV parameters {size, function [tricuspid annular plane systolic excursion (TAPSE), RV fractional area change (RV‐FAC), and RV myocardial performance index (RV‐MPI)], pulmonary artery systolic pressure (PASP), and tricuspid regurgitation}; left ventricular ejection fraction (LVEF), left ventricular end‐diastolic volume index (LVEDVi), and left atrial volume index (LAVi); and cardiopulmonary exercise test (CPET) [peak VO₂, minute ventilation/carbon dioxide production (VE/VCO₂), 6 min walk distance (6MWD), and submaximal exercise duration (SED)]. We also studied the relationship between RV‐PA coupling (TAPSE/PASP ratio) and echocardiographic parameters in patients with both data available. Univariate and multivariate linear regression models were used. Patients enrolled in EARTH (overall population) were mostly male (73.2%), mean age 61.0 ± 9.8 years, New York Heart Association class II–III (87.8%), mean LVEF of 26.6 ± 7.7%, and reduced peak VO₂ (15.1 ± 4.6 mL/kg/min). Of these, 100 had both TAPSE and PASP available (TAPSE/PASP population): they exhibited higher BNP, wider QRS duration, larger LVEDVi, with more having tricuspid regurgitation compared with the 105 patients for whom these values were not available (all P < 0.05). RV‐FAC (β = 7.5), LAVi (β = −0.1), and sex (female, β = −1.9) predicted peak VO₂ in the overall population (all P = 0.01). When available, TAPSE/PASP ratio was the only echocardiographic parameter associated with peak VO₂ (β = 6.8; P < 0.01), a threshold ≤0.45 predicting a peak VO₂ ≤ 14 mL/kg/min (0.39 for VO₂ ≤ 12). RV‐MPI was the only echocardiographic parameter associated with ventilatory inefficiency (VE/VCO₂) and 6MWD (β = 21.9 and β = −69.3, respectively, both P ≤ 0.01) in the overall population. In presence of TAPSE/PASP, it became an important predictor for those two CPET (β = −18.0 and β = 72.4, respectively, both P < 0.01), together with RV‐MPI (β = 18.5, P < 0.01) for VE/VCO₂. Tricuspid regurgitation predicted SED (β = −3.2, P = 0.03).

Conclusions

Right ventricular function assessed by echocardiography (RV‐MPI and RV‐FAC) is closely associated with exercise tolerance in patients with HFrEF. When the TAPSE/PASP ratio is available, this marker of RV‐PA coupling becomes the stronger echocardiographic predictor of exercise capacity in this population, highlighting its potential role as a screening tool to identify patients with reduced exercise capacity and potentially triage them to formal peak VO₂ and/or evaluation for advanced HF therapies.

Prognostic value of galectin-3 and right ventricular function for long-term mortality in heart failure patients treated with cardiac resynchronization therapy

Recently, associations between the biomarker galectin-3 and numerous pathological processes involved in heart failure (HF) and right ventricular (RV) function have been observed. We aimed to assess the long-term prognostic ability of galectin-3 and RV function parameters for all-cause mortality in HF patients treated with cardiac resynchronization therapy (CRT). We prospectively studied 63 symptomatic HF patients with a left ventricular (LV) ejection fraction (EF) ≤ 35%. The median serum galectin-3 concentration was 13.4 ng/mL (IQR 11.05, 17.15). A detailed assessment of LV and RV geometry and function was performed with echocardiography. CRT defibrillator implantation was achieved in all patients without major complications. The follow-up lasted 5 years. In the multivariable Cox regression model, independent predictors for all-cause mortality were log baseline galectin-3 and baseline RV function expressed as tricuspid annular plane systolic excursion with HR 2.96 (p = 0.037) and HR 0.88 (p = 0.023), respectively. Analysis of subgroups defined by galectin-3 concentration and CRT response showed that patients with high baseline galectin-3 concentrations and a lack of response to CRT had a significantly lower probability of survival. In our patient cohort, the baseline galectin-3 concentration and RV function were independent predictors of long-term all-cause mortality in HFrEF patients following CRT implantation.

Impact of right ventricular contractile reserve during low-load exercise on exercise intolerance in heart failure

AIMS

Traditional criteria for heart transplantation by cardiopulmonary exercise testing (CPX) include peak oxygen uptake (VO2 ) < 14 mL/kg/min. Reaching a sufficient exercise load is challenging for patients with refractory heart failure (HF) because of their exercise intolerance. Recently, a substantial impact of right ventricular (RV) dysfunction was highlighted on urgent heart transplantation and mortality. This study aims to investigate the impact of RV contractile reserve, assessed by low-load exercise stress echocardiography (ESE), on exercise intolerance defined as peak VO2  < 14 mL/kg/min, in patients with HF.

METHODS AND RESULTS

We prospectively examined 67 consecutive patients hospitalized for HF who underwent ESE and CPX under a stabilized HF condition. Although low-load ESE was defined as 25 W load exercise, an increment in RV systolic (s') velocity was regarded as the preservation of RV contractile reserve. All patients completed low-load ESE. During low-load ESE, the variation in RV s' velocity significantly correlated with peak VO2 (r = 0.787, P < 0.001). The change in RV s' velocity during low-load ESE accurately identified patients with peak VO2  < 14 mL/kg/min (area under the curve, 0.95; sensitivity, 92%; specificity, 85%). The intraclass correlation coefficient for intra-observer and inter-observer agreement for the change in RV s' velocity was 0.96 (95% confidence interval, 0.88-0.99, P < 0.001) and 0.86 (95% confidence interval, 0.64-0.95, P < 0.001), respectively. The RV-to-pulmonary circulation (PC) coupling, which was assessed by the slope of the relationship between RV s' velocity and pulmonary artery systolic pressure at rest and low-load exercise, was worse in the low-peak VO2 group (<14 mL/kg/min) than the preserved-peak VO2 group (≥14 mL/kg/min).

CONCLUSIONS

The change in RV s' velocity during low-load ESE could estimate the exercise capacity in HF patients. The assessments of RV contractile reserve and RV-to-PC coupling could be clinically beneficial to distinguish high-risk HF patients.

Galectin-3 is related to right ventricular dysfunction in heart failure patients with reduced ejection fraction and may affect exercise capacity

Galectin-3 is a biomarker of fibrosis, inflammation and oxidative stress, and its role in heart remodelling and exercise intolerance has not been conclusively proven in heart failure (HF) patients with reduced ejection fraction (rEF). We prospectively assessed 67 consecutive patients with symptomatic HF and left ventricular (LV) EF ≤ 35% during optimal medical therapy, with a mean serum galectin-3 concentration of 15.3 ± 6.4 and a median of 13.5 ng/mL. The group with galectin-3 concentrations greater than or equal to the median had significantly worse right ventricular (RV) systolic function parameters (s′, TAPSE), higher pulmonary artery systolic pressure, more advanced tricuspid regurgitation and lower RV-to-pulmonary circulation coupling index, while no significant differences were found in LV parameters. Moreover, this group achieved significantly lower parameters in cardiopulmonary exercise testing. Significant negative correlations were found between galectin-3 concentration and RV parameters and exercise capacity parameters and have persisted after adjustment for glomerular filtration rate, but not all of them have persisted after adjustment for NT-proBNP. Multivariate regression analysis revealed that TAPSE (β coefficient: − 0.605; p < 0.001) and heart rate at peak exercise (β coefficient: − 0.98; p = 0.009) were independently related to galectin-3 concentration. Elevated galectin-3 concentration in patients with HFrEF might indicate concomitant RV dysfunction and exercise intolerance.