Changes of ventricular and peripheral performance in patients with heart failure and normal ejection fraction: insights from ergometry stress echocardiography

Additive effects of type 2 diabetes and metabolic syndrome on left ventricular torsion and linear deformation abnormalities during dobutamine stress echocardiography

Objective

The interplay between metabolic syndrome (MS) and type 2 diabetes (T2D) on regional myocardial mechanics and the potential additional effects of their combination remain poorly understood. In this context, we evaluated left ventricular (LV) torsion and linear deformation at rest and under dobutamine (DB) stress in patients with T2D, MS or both.

Methods

Thirty-nine T2D patients without MS (T2D), 37 MS patients free from T2D (MS), 44 patients with both T2D and MS (T2D-MS group) and 38 healthy patients (control group) were prospectively recruited. Speckle-tracking echocardiography (STE) was conducted at rest and low dose DB to evaluate LV myocardial longitudinal (LS) as well as circumferential (CS) strain and early diastolic strain rate (LSrd, CSrd) and twist-untwist mechanics.

Results

At rest, MS, T2D and controls presented with similar resting LS and LSrd while significant lower values were obtained in T2D-MS compared to controls. DB revealed reduced LS, LSrd, CS and CSrd in MS and T2D groups compared to controls. In T2-MS, the decline in LS and LSrd established at rest was exacerbated under DB. Stress echocardiography revealed also lower basal rotation and subsequently lower twist in MS and T2D patients compared to controls. T2D-MS showed major impairments of apical rotation and twist under DB stress, with values significantly lower compared to the 3 other groups. From stepwise multiple linear regression analysis, epicardial adipose tissue for Δ (rest to DB) LS, numbers of MS factors for Δ CS and Δ Twist emerged as major independent predictors.

Conclusion

These results demonstrate synergic and additive effects of T2D and MS on LV torsion and linear deformation abnormalities in asymptomatic patients with metabolic diseases. They also highlight the usefulness of speckle tracking echocardiography under DB stress in detecting multidirectional myocardial mechanics impairments that can remain barely detectable at rest, such as in isolated T2D or MS patients.

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].

Exercise Systolic Reserve and Exercise Pulmonary Hypertension Improve Diagnosis of Heart Failure With Preserved Ejection Fraction

Aims

Diastolic stress testing (DST) is recommended to confirm heart failure with preserved ejection fraction (HFpEF) in patients with exertional dyspnea, but current algorithms do not detect all patients. We aimed to identify additional echocardiographic markers of elevated pulmonary arterial wedge pressure during exercise (exPAWP) in patients referred for DST.

Methods and Results

We identified candidate parameters in 22 patients referred for exercise right heart catheterization with simultaneous echocardiography. Elevated exPAWP (≥25 mmHg) was present in 14 patients, and was best identified by peak septal systolic annular velocity <9.5 cm/s [exS', area under the receiver operating characteristic curve (AUC) 0.97, 95% confidence interval 0.92–1.0] and mean pulmonary artery pressure/cardiac output slope ≥3.2 mmHg/L [mPAP/CO, AUC 0.88 (0.72–1.0)]. We propose a decision tree to identify patients with elevated exPAWP. Applying this decision tree to 326 patients in an independent non-invasive DST cohort showed that patients labeled as “high probability of HFpEF” (n = 85) had reduced peak oxygen uptake [13.0 (10.7–15.1) mL/kg/min, p < 0.001 vs. intermediate/low probability], high H2FPEF score [53 (40–72) %, p < 0.001 vs. intermediate/low probability], and typical clinical characteristics. The diagnostic yield of DST increased from 11% using exercise E/e', to 62% using the decision tree.

Conclusion

In DST for suspected HFpEF, exS' was the most accurate echocardiographic parameter to identify elevated PAWP. We propose a decision tree including exS' and mPAP/CO for interpretation of DST. Application of this decision tree revealed typical HFpEF characteristics in patients labeled as high probability of HFpEF, and substantially reduced the number of inconclusive results.

Determining the thresholds for abnormal left ventricular strains in healthy subjects by echocardiography: a meta-analysis

Background

Left ventricular global longitudinal strain (LVGLS), circumferential strain (LVGCS) and radial strain (LVGRS) are echocardiographic parameters with wide clinical applicability. However, the thresholds for abnormal left ventricular (LV) strains, particularly the lower limits of normal (LLN), are not well established. This meta-analysis determined the mean and LLN of two- (2D) and three-dimensional (3D) LV strain in healthy subjects and factors that influence strain measurements.

Methods

We searched PubMed, Embase and Cochrane databases until 31 December 2019 for studies reporting left ventricular (LV) global strain in at least 50 healthy subjects. We pooled means and LLNs of 2D and 3D LV strain using random-effects models, and performed subgroup and meta-regression analysis for LVGLS.

Results

Forty-four studies were eligible totaling 8,910 subjects. The pooled means and LLNs (95% confidence intervals) were -20.1% (-20.7%, -19.6%) and -15.4% (-16.0%, -14.7%) respectively for 2D-LVGLS; -21.9% (-23.4%, -20.3%) and -15.3% (-16.9%, -13.8%) respectively for 2D-LVGCS; and 48.4% (43.8%, 53.0%) and 25.5% (17.8%, 33.1%) respectively for 2D-LVGRS. All pooled analyses demonstrated significant heterogeneity, and means and LLNs of and 3D-LV strains differed marginally from 2D. Only vendor software was associated with differences in pooled means and LLN of 2D-LVGLS.

Conclusions

In conclusion, pooled means and LLNs of 2D- and 3D-LV global strain parameters in healthy subjects were reported. Based on the pooled LLNs, thresholds for abnormal, borderline and normal strains can be defined, such as less negative than -14.7%, between -14.7% and -16.0% and more negative than -16.0% respectively for 2D-LVGLS, and 2D-LVGLS values are only affected by vendor software.

Obstructive sleep apnoea, intermittent hypoxia and heart failure with a preserved ejection fraction

Obstructive sleep apnoea (OSA) is recognised to be a potent risk factor for hypertension, coronary heart disease, strokes and heart failure with a reduced ejection fraction. However, the association between OSA and heart failure with a preserved ejection fraction (HFpEF) is less well recognised. Both conditions are very common globally.It appears that there are many similarities between the pathological effects of OSA and other known aetiologies of HFpEF and its postulated pathophysiology. Intermittent hypoxia induced by OSA leads to widespread stimulation of the sympathetic nervous system, renin-angiotensin-aldosterone system and more importantly a systemic inflammatory state associated with oxidative stress. This is similar to the consequences of hypertension, diabetes, obesity and ageing that are the common precursors to HFpEF. The final common pathway is probably via the development of myocardial fibrosis and structural changes in collagen and myocardial titin that cause myocardial stiffening. Thus, considering the pathophysiology of OSA and HFpEF, OSA is likely to be a significant risk factor for HFpEF and further trials of preventive treatment should be considered.

Saudi Heart Association (SHA) guidelines for the management of heart failure

Heart failure (HF) is the leading cause of morbidity and mortality worldwide and negatively impacts quality of life, healthcare costs, and longevity. Although data on HF in the Arab population are scarce, recently developed regional registries are a step forward to evaluating the quality of current patient care and providing an overview of the clinical picture. Despite the burden of HF in Saudi Arabia, there are currently no standardized protocols or guidelines for the management of patients with acute or chronic heart failure. Therefore, the Heart Failure Expert Committee, comprising 13 local specialists representing both public and private sectors, has developed guidelines to address the needs and challenges for the diagnosis and treatment of HF in Saudi Arabia. The ultimate aim of these guidelines is to assist healthcare professionals in delivering optimal care and standardized clinical practice across Saudi Arabia.

Value of Strain Imaging and Maximal Oxygen Consumption in Patients With Hypertrophic Cardiomyopathy

Longitudinal strain (LS) has been shown to be predictive of outcome in hypertrophic cardiomyopathy (HC). Percent predicted peak oxygen uptake (ppVO₂), among other cardiopulmonary exercise testing (CPX) metrics, is a strong predictor of prognosis in HC. However, there has been limited investigation into the combination of LS and CPX metrics. This study sought to determine how LS and parameters of exercise performance contribute to prognosis in HC. One hundred and thirty-one consecutive patients with HC who underwent CPX and stress echocardiography were included. Global, septal, and lateral LS were assessed at rest and stress. Eighty matched individuals were used as controls. Patients were followed for the composite end point of death and worsening heart failure. All absolute LS components were lower in patients with HC than in controls (global 14.3 ± 4.0% vs 18.8 ± 2.2%, p <0.001; septal 11.9 ± 4.9% vs 17.9 ± 2.7%, p <0.001; lateral 16.0 ± 4.7% vs 19.4 ± 3.1%, p = 0.001). Global strain reserve was also reduced in patients with HC (13 ± 5% vs 19 ± 8%, p = 0.002). Over a median follow-up of 56 months (interquartile range 14 to 69), the composite end point occurred in 53 patients. Global LS was predictive of outcome on univariate analysis (0.55 [0.41 to 0.74], p <0.001). When combined with CPX metrics, lateral LS was the only strain variable predictive of outcome along with indexed left atrial volume (LAVI) and ppVO₂. The worst outcomes were observed for patients with lateral LS <16.1%, LAVI >52 ml/m², and ppVO₂ <80%. The combination of lateral LS, LAVI, and ppVO₂ presents a simple model for outcome prediction.

Contractile reserve and cardiopulmonary exercise parameters in patients with dilated cardiomyopathy, the two dimensions of exercise testing

BACKGROUND

Left ventricular (LV) contractile reserve assessed using imaging and cardiopulmonary exercise testing (CPX) has been shown to predict outcome in patients with dilated cardiomyopathy (DCM). Few clinical studies have, however, analyzed the relationship between them.

METHODS

A cohort of 75 ambulatory patients with DCM underwent stress treadmill echocardiography with CPX. LV contractile reserve was calculated as absolute change (ΔLVEF=LVEF_peak -LVEF_rest ) and percent change (%LVEF=[(LVEF_peak -LVEF_rest )/LVEF_peak) ]×100) in LVEF, circumferential and longitudinal strain (LS). Exercise capacity was measured as peak oxygen uptake (peak VO₂ ) and ventilatory efficiency as the slope of minute ventilation to CO₂ production (VE/VCO₂ slope). Values of contractile reserve were compared to matched controls. We also explored which metric of ventricular response (absolute or percent change) was less dependent on baseline LV function.

RESULTS

Patients with DCM had a mean age, rest and peak LVEF of 44±10 years, 42±10% and 50±12%, respectively. Among parameters of contractile reserve, peak cardiac output was the strongest parameter associated with peak VO₂ (r=.63, P<.001). Along with age, sex, and BMI, it explained more than 70% of the variance in peak VO₂ . In contrast, LVEF and LS were only weakly related to peak VO₂ . With regard to ventilatory efficiency, the strongest parameter that emerged was right atrial volume index (r=.36, P<.001). Percent change in LVEF was more independent of baseline function than absolute change.

CONCLUSION

Echocardiographic contractile reserve and CPX provide complementary information. Percent change in contractile reserve was most independent of baseline function, therefore may be preferred when analyzing the ventricular response to exercise.

Impaired left ventricular global longitudinal strain in patients with heart failure with preserved ejection fraction: insights from the RELAX trial

BACKGROUND

While abnormal left ventricular (LV) global longitudinal strain (GLS) has been described in patients with heart failure with preserved ejection fraction (HFpEF), its prevalence and clinical significance are poorly understood.

METHODS AND RESULTS

Patients enrolled in the RELAX trial of sildenafil in HFpEF (LV ejection fraction ≥50%) in whom two-dimensional, speckle-tracking LV GLS was possible (n = 187) were analysed. The distribution of LV GLS and its associations with clinical characteristics, LV structure and function, biomarkers, exercise capacity and quality of life were assessed. Baseline median LV GLS was -14.6% (25th and 75th percentile, -17.0% and -11.9%, respectively) and abnormal (≥ - 16%) in 122/187 (65%) patients. Patients in the tertile with the best LV GLS had lower N-terminal pro-brain natriuretic peptide (NT-proBNP) [median 505 pg/mL (161, 1065) vs. 875 pg/mL (488, 1802), P = 0.008) and lower collagen III N-terminal propeptide (PIIINP) levels [median 6.7 µg/L (5.1, 8.1) vs. 8.1 µg/L (6.5, 10.5), P = 0.001] compared with the tertile with the worst LV GLS. There was also a modest linear relationship with LV GLS and log-transformed NT-proBNP and PIIINP (r = 0.29, P < 0.001 and r = 0.19, P = 0.009, respectively). We observed no linear association of LV GLS with Minnesota Living with Heart Failure scores, 6-min walk distance, peak oxygen consumption, or expiratory minute ventilation/carbon dioxide excretion slope.

CONCLUSIONS

Impaired LV GLS is common among HFpEF patients, indicating the presence of covert systolic dysfunction despite normal LV ejection fraction. Impaired LV GLS was associated with biomarkers of wall stress and collagen synthesis and diastolic dysfunction but not with quality of life or exercise capacity, suggesting other processes may be more responsible for these aspects of the HFpEF syndrome.

Association of impaired left ventricular twisting-untwisting with vascular dysfunction, neurohumoral activation and impaired exercise capacity in hypertensive heart disease

AIMS

We investigated the association between left ventricular (LV) torsional deformation and vascular dysfunction, fibrosis, neurohumoral activation, and exercise capacity in patients with normal ejection fraction

METHODS AND RESULTS

In 320 newly-diagnosed untreated hypertensive patients and 160 controls, we measured: pulse wave velocity (PWV); coronary flow reserve (CFR) by Doppler echocardiography; global longitudinal strain and strain rate, peak twisting, the percentage changes between peak twisting, and untwisting at mitral valve opening (%dpTw - UtwMVO ), at peak (%dpTw - UtwPEF ), and the end of early LV diastolic filling (%dpTw - UtwEDF ) by speckle tracking imaging; transforming growth factor (TGFb-1), metalloproteinase-9 (MMP-9), tissue inhibitor of matrix metalloptoteinase-1(TIMP-1), markers of collagen synthesis, and N-terminal pro-brain natriuretic peptide (NT-proBNP). Oxygen consumption (VO2 ), measured by means of cardiopulmonary exercise test, was assessed in a subset of 80 patients. The PWV, CFR, longitudinal strain and strain rate, %dpTw-UtwMVO , %dpTw-UtwPEF , and %dpTw-UtwEDF were impaired in hypertensive patients compared with controls. In multivariable analysis, CFR, PWV, LV mass, and systolic blood pressure were independent determinants of longitudinal strain, strain rate, and untwisting markers (P < 0.05). Increased TGFb-1 was related with increased collagen synthesis markers, TIMP-1 and MMP-9 and these biomarkers were associated with impaired longitudinal systolic strain rate, untwisting markers, CFR and PWV (P < 0.05). Delayed untwisting as assessed by reduced %dpTw - UtwEDF was related with increased NT-proBNP and reduced VO2 (P < 0.05).

CONCLUSIONS

Impaired LV untwisting is associated with increased arterial stiffness and coronary microcirculatory dysfunction, and is linked to reduced exercise capacity and neurohumoral activation in hypertensive heart disease. A fibrotic process may be the common link between vascular dysfunction and abnormal myocardial deformation.

Left ventricular long-axis performance during exercise is an important prognosticator in patients with heart failure and preserved ejection fraction

BACKGROUND

Although many prognostic variables have been reported, the risk stratification of patients with heart failure and preserved ejection fraction (HFPEF) has long been controversial due to considerable discordance. Ergometry stress echocardiography may provide a more clinical relevant evaluation in HFPEF. We aimed at evaluating the prognostic value of echocardiographic parameters during exercise in HFPEF patients.

METHODS

Comprehensive echocardiographic examination with symptom-limited exercise testing on a semi-recumbent and tilting bicycle Ergometer (Lode BV, Groningen, the Netherlands) was performed on 80 consecutive HFPEF patients (aged 66±8years; 64% male). The exercise images for two-dimensional (2D) speckle tracking analysis were acquired with heart rate of 90-100bpm, while exercise images for tissue Doppler imaging (TDI) and M-mode echocardiography were stored with attainment of >85% of maximal age-predicted heart rate. All patients were followed up for 3years after stress echocardiography for all-cause mortality and/or heart failure (HF) hospitalization.

RESULTS

During the follow-up, 43 (54%) patients reached the combined end point: 5 (6%) patients died, and another 38 (48%) patients experienced HF hospitalizations. Univariate predictors were: decreased resting left atrial ejection fraction (LAEF), lower peak heart rate, elevated E/e' ratio, reduced TDI myocardial velocities, and impaired 2D global longitudinal strain (GLS) during exercise. Only impaired GLS (hazard ratio [HR] 0.79, 95% confidence interval [CI] 0.67 to 0.91) remained independent after multivariate analysis (p=0.008).

CONCLUSIONS

More than half of the HFPEF patients died or were hospitalized for HF at 3-year follow-up and this was significantly related to impaired left ventricular long-axis function during exercise.