Lower limit of normality and clinical relevance of left ventricular early diastolic strain rate for the detection of left ventricular diastolic dysfunction

Evaluation of Intraoperative Left-Ventricular Diastolic Function by Myocardial Strain in On-Pump Coronary Artery Bypass Surgery

OBJECTIVES

Left ventricular (LV) diastolic function strongly predicts outcomes after cardiac surgery, but there is no consensus about appropriate intraoperative assessment. Recently, intraoperative diastolic strain-based measurements assessed by transesophageal echocardiography (TEE) have shown a strong correlation with LV relaxation, compliance, and filling, but there are no reports about evaluation through the entire perioperative period. Therefore, the authors describe the intraoperative course of this novel assessment technique in patients who underwent coronary artery bypass grafting, and compare it with conventional echocardiographic measures and common grading algorithms of LV diastolic dysfunction (LVDD).

DESIGN

Prospectively obtained data.

SETTING

A single university hospital.

PARTICIPANTS

Thirty adult patients scheduled for isolated on-pump coronary artery bypass grafting surgery with preoperative preserved left and right ventricular systolic function, without significant heart valve disease and pulmonary hypertension, and an uneventful intraoperative course were included.

INTERVENTIONS

Transesophageal echocardiography was performed after induction of anesthesia (T1), after termination of cardiopulmonary bypass (T2), and after sternal closure (T3). Echocardiographic evaluation was performed in stable hemodynamic conditions, in sinus rhythm or atrial pacing, and vasopressor support with norepinephrine ≤0.1 µg/kg/min.

MEASUREMENTS AND MAIN RESULTS

Strain-based measurements of peak longitudinal strain rate during isovolumetric relaxation (SR-IVR) and during early (SR-E) and late (SR-A) LV filling were assessed using EchoPAC v204 software (GE Vingmed Ultrasound AS, Norway). Evaluation of conventional echocardiographic parameters included transmitral Doppler measures of early (E) and late (A) LV filling, as well as lateral-tissue Doppler velocity assessed during early (e´) and late (a´) LV filling, tricuspid regurgitation, and left atrial dilatation. Evaluation and grading of LV diastolic function by myocardial strain was feasible in all included patients at all time points of assessment. Using conventional grading algorithms, however, a substantial number of patients could not be sufficiently graded, falling into an indeterminate zone and not reliably estimating LVDD (T1, 40%; T2, 33%; T3, 36%). There was significant impairment of LV diastolic function after bypass, as measured by SR-IVR (T1 v T2, 0.28 s-1 [IQR 0.23; 0.31) v 0.18 s-1 [IQR 0.14; 0.22]; p < 0.001), SR-E (T1 v T2, 0.95 ± 0.34 s-1v 1.28 ± 0.36 s-1; p < 0.001), and E/SR-IVR (T1 v T2, 2.3 ± 1.0 m v 4.5 ± 2.1 m; p < 0.001]. Conventional echocardiographic measures remained unchanged during the same period (E/A T1 v T2, 1.27 [IQR 0.94; 1.59] v 1.21 [IQR 1.03; 1.47] [p = 1] and E/e´ T1 v T2, 7.0 [IQR 5.3; 9.6] v 6.35 [IQR 5.7; 9.9] [p = 0.9]). There were no significant changes in the values of SR-IVR, SR-E, SR-A, E/SR-IVR, E/A, and E/e´ before and after sternal closure (T2 v T3).

CONCLUSION

Intraoperative assessment of strain-based measurements of LV diastolic function and strain-based LVDD grading was feasible in this group of selected patients, whereas conventional parameters failed to describe LVDD sufficiently in a substantial number of patients. Diastolic strain-based measurements showed impairment of LV relaxation and compliance after bypass, which was not detected by conventional echocardiographic parameters. Therefore, diastolic myocardial strain analysis might be more sensitive in detecting myocardial diastolic dysfunction by TEE in the perioperative setting, with its dynamic changes of loading conditions, and might provide valuable and additional information on the perioperative changes of LV diastolic function.

Ratio of transmitral early filling velocity to diastolic strain rate and prognosis in type-1 diabetes

BACKGROUND

Impaired diastolic function is a hallmark of diabetic cardiomyopathy and a common feature in type 1 diabetes mellitus (T1DM). The ratio of transmitral early filling velocity to early diastolic strain rate (E/e'sr) has in recent studies proved to have strong prognostic value. This study aimed to investigate the prognostic value of E/e'sr compared to E/e' in T1DM without known heart disease.

METHODS

In this prospective cohort of T1DM patients, echocardiography was performed including two-dimensional speckle tracking. Follow-up was performed using nationwide registries. Outcomes were all-cause mortality and major cardiovascular events (MACE).

RESULTS

In total 1079 patients (age: 49.6 ± 14.5 years, 52.5% male, duration of diabetes 25.8 ± 14.6 years) were included in the study. During follow-up (median 6.3 years, IQR:5.7-6.9) 13.2% experienced MACE and 5.8% died. Following multivariable adjustment, both E/e'sr and E/e' was significantly associated with both MACE (E/e'sr: HR 1.16 CI95%:[1.05-1.29], p = 0.005, per 10 cm increase) vs. (E/e': HR 1.09 CI95%:[1.03-1.15], p = 0.001, per 1 unit increase) and all-cause mortality (E/e'sr: HR 1.20 [1.03-1.40], p = 0.016) vs. (E/e': HR: 1.11 [1.02-1.20], p = 0.016). Sex modified the association between E/e'sr and MACE (p for interaction = 0.008) such that E/e'sr after multivariable adjustment only remained significantly associated with MACE in females (HR: 1.41 [1.19-1.67], p < 0.001) but not in males (HR: 1.06 [0.93-1.20], p = 0.42). In females, E/e'sr provided incremental information beyond the Steno T1 Risk Engine (Harrell's C-statistic: 0.78 (0.72-0.83) vs. 0.81 (0.75-0.86), p = 0.007).

CONCLUSION

In patients with T1DM, both E/e'sr and E/e' provides independent prognostic information regarding prognosis. E/e'sr seems to have stronger prognostic value in females with T1DM.

Normal Values and Reference Ranges for the Ratio of Transmitral Early Filling Velocity to Early Diastolic Strain Rate: The Copenhagen City Heart Study

BACKGROUND

The ratio of transmitral early filling velocity to early diastolic strain rate (E/e'sr) has recently emerged as a measure of left ventricular filling pressure. Reference values are needed for this new parameter for it to be used clinically.

METHODS

Healthy participants from a prospective general population study, the Fifth Copenhagen City Heart Study, were assessed to establish reference values for E/e'sr derived from two-dimensional speckle-tracking echocardiography. The prevalence of abnormal E/e'sr was assessed in participants with cardiovascular risk factors or specific diseases.

RESULTS

The population comprised 1,623 healthy participants (median age, 45; interquartile range, 32-56; 61% female). The upper reference limit for E/e'sr in the population was 79.6 cm. Following multivariable adjustment, male participants exhibited significantly higher E/e'sr than female participants (upper reference limit for male participants, 83.7 cm; for female participants, 76.5 cm). For both sexes, E/e'sr increased in a curvilinear fashion with age such that the largest increases in E/e'sr were observed in participants >45 years. In the entire CCHS5 population with E/e'sr available (n = 3,902), increasing age, body mass index, systolic blood pressure, male sex, estimated glomerular filtration rate, and diabetes were associated with E/e'sr (all P < .05). Total cholesterol was associated with a less steep increase in E/e'sr. Abnormal E/e'sr was seldomly observed in participants with normal diastolic function but became more frequent in participants with increasing grades of diastolic dysfunction (normal, mild, moderate, severe [abnormal E/e'sr for each grade: 4.4% vs 20.0% vs 16.2% vs 55.6%, respectively]).

CONCLUSION

The E/e'sr differs between sexes and is age dependent such that E/e'sr increases with advancing age. Therefore, we established sex- and age-stratified reference values for E/e'sr.

Detection of Early Myocardial Dysfunction by Imaging Biomarkers in Cancer Patients Undergoing Photon Beam vs. Proton Beam Radiotherapy: A Prospective Study

1. Background: We sought to determine acute and subacute changes in cardiac function after proton beam (PBT) and photon beam (PhT) radiotherapy (RT) using conventional and two-dimensional speckle tracking echocardiography (2D-STE) in patients with malignant breast and thoracic tumors. 2. Methods: Between March 2016 and March 2017, 70 patients with breast or thoracic cancer were prospectively enrolled and underwent transthoracic echocardiography with comprehensive strain analysis at pretreatment, mid-treatment, end of treatment, and 3 months after RT. 3. Results: PBT was used to treat 44 patients; PhT 26 patients. Mean ± SD age was 55 ± 12 years; most patients (93%) were women. The median (interquartile range) of the mean heart dose was lower in the PBT than the PhT group (47 [27-79] vs. 217 [120-596] cGy, respectively; p < 0.001). Ejection fraction did not change in either group. Only the PhT group had reduced systolic tissue Doppler velocities at 3 months. 2D-STE showed changes in endocardial and epicardial longitudinal, radial, and circumferential early diastolic strain rate (SRe) in patients undergoing PhT (global longitudinal SRe, pretreatment vs. end of treatment (p = 0.04); global circumferential SRe, pretreatment vs. at 3-month follow-up (p = 0.003); global radial SRe, pretreatment vs. at 3-month follow-up (p = 0.02) for endocardial values). Epicardial strain values decreased significantly only in patients treated with PhT. Patients in the PhT group had a significant decrease in epicardial global longitudinal systolic strain rate (GLSRs) (epicardial GLSRs, at baseline vs. at end of treatment [p = 0.009]) and in GCSRe and GRSRe (epicardial GCSRe, at baseline vs. at 3-month follow-up (p = 0.02); epicardial GRSRe, at baseline vs. at 3-month follow-up (p = 0.03)) during treatment and follow-up. No changes on 2D-STE were detected in the PBT group. 4. Conclusions: Patients who underwent PhT but not PBT had reduced tissue Doppler velocities and SRe values during follow-up, suggesting early myocardial relaxation abnormalities. PBT shows promise as a cardiac-sparing RT technology.

Noninvasive assessment of myocardial work during left ventricular isovolumic relaxation in patients with diastolic dysfunction

BACKGROUND

This study aims to investigate the value of myocardial work (MW) parameters during the isovolumic relaxation (IVR) period in patients with left ventricular diastolic dysfunction (LVDD).

METHODS

This study prospectively recruited 448 patients with risks for LVDD and 95 healthy subjects. An additional 42 patients with invasive measurements of left ventricular (LV) diastolic function were prospectively included. The MW parameters during IVR were noninvasively measured using EchoPAC.

RESULTS

The total myocardial work during IVR (MW_IVR), myocardial constructive work during IVR (MCW_IVR), myocardial wasted work during IVR (MWW_IVR), and myocardial work efficiency during IVR (MWE_IVR) of these patients were 122.5 ± 60.1 mmHg%, 85.7 ± 47.8 mmHg%, 36.7 ± 30.6 mmHg%, and 69.4 ± 17.8%, respectively. The MW during IVR was significantly different between patients and healthy subjects. For patients, MWE_IVR and MCW_IVR were significantly correlated with the LV E/e' ratio and left atrial volume index, MWE_IVR exhibited a significant correlation with the maximal rate of decrease in LV pressure (dp/dt per min) and tau, and the MWE_IVR corrected by IVRT also exhibited a significant correlation with tau.

CONCLUSIONS

MW during IVR significantly changes in patients with risks for LVDD, and is correlated to LV conventional diastolic indices, including dp/dt min and tau. Noninvasive MW during IVR may be a promising tool to evaluate the LV diastolic function.

Advances in Multimodality Cardiovascular Imaging in the Diagnosis of Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a syndrome defined by the presence of heart failure symptoms and increased levels of circulating natriuretic peptide (NP) in patients with preserved left ventricular ejection fraction and various degrees of diastolic dysfunction (DD). HFpEF is a complex condition that encompasses a wide range of different etiologies. Cardiovascular imaging plays a pivotal role in diagnosing HFpEF, in identifying specific underlying etiologies, in prognostic stratification, and in therapeutic individualization. Echocardiography is the first line imaging modality with its wide availability; it has high spatial and temporal resolution and can reliably assess systolic and diastolic function. Cardiovascular magnetic resonance (CMR) is the gold standard for cardiac morphology and function assessment, and has superior contrast resolution to look in depth into tissue changes and help to identify specific HFpEF etiologies. Differently, the most important role of nuclear imaging [i.e., planar scintigraphy and/or single photon emission CT (SPECT)] consists in the screening and diagnosis of cardiac transthyretin amyloidosis (ATTR) in patients with HFpEF. Cardiac CT can accurately evaluate coronary artery disease both from an anatomical and functional point of view, but tissue characterization methods have also been developed. The aim of this review is to critically summarize the current uses and future perspectives of echocardiography, nuclear imaging, CT, and CMR in patients with HFpEF.

Longitudinal Assessment of Cardiac Outcomes of Multisystem Inflammatory Syndrome in Children Associated With COVID-19 Infections

Background

In multisystem inflammatory syndrome in children, there is paucity of longitudinal data on cardiac outcomes. We analyzed cardiac outcomes 3 to 4 months after initial presentation using echocardiography and cardiac magnetic resonance imaging.

Methods and Results

We included 60 controls and 60 cases of multisystem inflammatory syndrome in children. Conventional echocardiograms and deformation parameters were analyzed at 4 time points: (1) acute phase (n=60), (2) subacute phase (n=50; median, 3 days after initial echocardiography), (3) 1‐month follow‐up (n=39; median, 22 days), and (4) 3‐ to 4‐month follow‐up (n=25; median, 91 days). Fourteen consecutive cardiac magnetic resonance imaging studies were reviewed for myocardial edema or fibrosis during subacute (n=5) and follow‐up (n=9) stages. In acute phase, myocardial injury was defined as troponin‐I level ≥0.09 ng/mL (>3 times normal) or brain‐type natriuretic peptide >800 pg/mL. All deformation parameters, including left ventricular global longitudinal strain, peak left atrial strain, longitudinal early diastolic strain rate, and right ventricular free wall strain, recovered quickly within the first week, followed by continued improvement and complete normalization by 3 months. Median time to normalization of both global longitudinal strain and left atrial strain was 6 days (95% CI, 3–9 days). Myocardial injury at presentation (70% of multisystem inflammatory syndrome in children cases) did not affect short‐term outcomes. Four patients (7%) had small coronary aneurysms at presentation, all of which resolved. Only 1 of 9 patients had residual edema but no fibrosis by cardiac magnetic resonance imaging.

Conclusions

Our short‐term study suggests that functional recovery and coronary outcomes are good in multisystem inflammatory syndrome in children. Use of sensitive deformation parameters provides further reassurance that there is no persistent subclinical dysfunction after 3 months.

3-Year Follow-Up of Radiation-Associated Changes in Diastolic Function by Speckle Tracking Echocardiography

Background

Radiation therapy (RT) results in myocardial changes consisting of diffuse fibrosis, which may result in changes in diastolic function.

Objectives

The aim of this study was to explore RT-associated changes in left ventricular (LV) diastolic function.

Methods

Sixty chemotherapy-naive patients with left-sided, early-stage breast cancer were studied with speckle tracking echocardiography at 3 time points: prior to, immediately after, and 3 years after RT. Global and regional early diastolic strain rate (SRe) were quantified, as were parameters of systolic function.

Results

Regional changes in SRe, particularly the apical and anteroseptal segments, were observed over time and were more evident than global changes. The apical SRe declined from a median of 1.24 (interquartile range: 1.01 to 1.39) s^-1 at baseline to 1.02 (interquartile range: 0.79 to 1.15) s^-1 at 3 years of follow-up (p < 0.001). This decline was associated with the left ventricular maximal radiation dose (β = 0.36, p = 0.007). The global SRe was <1.00 s^-1 (SRe_dep) in 11 (18.3%) patients at baseline, 21 (35%) patients (p = 0.013) post-RT, and 17 (28.3%) patients (p = 0.051) at 3 years. SRe_dep post-RT was independently associated with baseline cardiac abnormalities (odds ratio: 0.26; 95% confidence interval: 0.08 to 0.84; p = 0.025); SRe_dep at 3 years of follow-up was associated with the baseline Charlson comorbidity index (odds ratio: 2.36; 95% confidence interval: 1.17 to 4.77; p = 0.017). Diastolic function abnormalities were evident even in patients with preserved global longitudinal strain at 3 years.

Conclusions

RT resulted in changes in the SRe in the apical and anteroseptal segments over 3 years of follow-up. Changes in SRe apical segments were present even in patients with preserved systolic function and were independently associated with RT dose and cardiovascular comorbidities.

Evaluation of Left Ventricular Diastolic Function by 2-D Speckle Tracking Echocardiography in Patients with Connective Tissue Disease-Associated Pulmonary Artery Hypertension

The purpose of this study was to evaluate the role of 2-D speckle tracking imaging in assessing left ventricular diastolic function in patients with connective tissue disease (CTD). A total of 98 CTD patients and 32 healthy controls were prospectively recruited. Early (E) and late (A) diastolic velocities of the transmitral flow were measured by pulsed Doppler echocardiography. Peak early diastolic myocardial velocity (E') was calculated on tissue Doppler echocardiography. The longitudinal strain rate (SR) was calculated as the average of three apical views, while circumferential and radial SRs were measured in three short-axis views. Pulmonary arterial hypertension (PAH) was defined as systolic pulmonary arterial pressure (sPAP) >36 mm Hg. Compared with the control group, CTD patients exhibited significant impairment of left ventricular diastolic function, manifested as lower global SR during early diastole (SRe) in the longitudinal deformation and higher E/SRe in both longitudinal and radial deformation. CTD-PAH patients had significantly lower SRe and higher E/SRe values in both the longitudinal and radial deformation compared with the patients with CTD without PAH. Pearson's correlation analysis revealed that sPAP levels correlated positively with E/E', longitudinal E/SRe, circumferential E/SRe and radial SRe, and it correlated negatively with septal E' and radial E/SRe. Receiver operating characteristic curve analysis suggested that E/E', longitudinal E/SRe and radial SRe could be used to predict PAH. The present study indicates that 2-D speckle tracking imaging is a useful method for evaluation of left ventricular diastolic function, and these derived parameters can serve as good predictors of PAH, but it may not be superior to the commonly used E/E' in CTD patients.

Left ventricular diastolic dysfunction and exercise intolerance in obese heart failure with preserved ejection fraction

This study tested the hypothesis that early left ventricular (LV) relaxation is impaired in older obese patients with heart failure with preserved ejection fraction (HFpEF), and related to decreased peak exercise oxygen uptake (peak V̇o₂). LV strain and strain rate were measured by feature tracking of magnetic resonance cine images in 79 older obese patients with HFpEF (mean age: 66 yr; mean body mass index: 38 kg/m²) and 54 healthy control participants. LV diastolic strain rates were indexed to cardiac preload as estimated by echocardiography derived diastolic filling pressures (E/e'), and correlated to peak V̇o₂. LV circumferential early diastolic strain rate was impaired in HFpEF compared with controls (0.93 ± 0.05/s vs. 1.20 ± 0.07/s, P = 0.014); however, we observed no group differences in early LV radial or longitudinal diastolic strain rates. Isolating myocardial relaxation by indexing all three early LV diastolic strain rates (i.e. circumferential, radial, and longitudinal) to E/e' amplified the group difference in early LV diastolic circumferential strain rate (0.08 ± 0.03 vs. 0.13 ± 0.05, P < 0.0001), and unmasked differences in early radial and longitudinal diastolic strain rate. Moreover, when indexing to E/e', early LV diastolic strain rates from all three principal strains, were modestly related with peak V̇o₂ (R = 0.36, -0.27, and 0.35, respectively, all P < 0.01); this response, however, was almost entirely driven by E/e' itself, (R = -0.52, P < 0.001). Taken together, we found that although LV relaxation is impaired in older obese patients with HFpEF, and modestly correlates with their severely reduced peak exercise V̇o₂, LV filling pressures appear to play a much more important role in determining exercise intolerance.NEW & NOTEWORTHY Using a multimodal imaging approach to uncouple tissue deformation from atrial pressure, we found that left ventricular (LV) relaxation is impaired in older obese patients with HFpEF, but only modestly correlates with their severely reduced peak V̇o₂. In contrast, the data show a much stronger relationship between elevated LV filling pressures and exercise intolerance, refocusing future therapeutic priorities.

Cardiovascular disease in young People with Type 1 Diabetes: Search for Cardiovascular Biomarkers

Premature onset of cardiovascular disease is common in people with type 1 diabetes and is relatively understudied in youth. Several reports in adolescents and young adults with diabetes demonstrate evidence of arterial stiffness and cardiac dysfunction, yet critical gaps exist in our current understanding of the temporal progression of cardiac and vascular dysfunction in these youth, and mechanistic investigations with robust pathophysiologic assessment are lacking. This review attempts to summarize relevant cardiovascular studies concerning children, adolescents, and young adults with type 1 diabetes. We focus on imaging-based biomarkers routinely applied to youth and adults that are well-established in their ability to predict adjudicated cardiovascular outcomes, and their relevant physiologic interpretation. Particularly, we focus the attention to 1) cardiac ventricular strain imaging techniques which are known to be predictive of clinical outcomes in patients with heterogenous causes of heart failure, and 2) stiffness in large arteries, a well-established prognostic marker of cardiovascular events. We conclude that there remains an urgent need for sensitive and quantitative biomarkers to define the natural history of cardiac and vascular disease origination and progression in type 1 diabetes, and set the stage for interpreting interventional studies focused on preventing, reversing or slowing disease progression.

Left ventricular global longitudinal strain in bicupsid aortic valve patients: head-to-head comparison between computed tomography, 4D flow cardiovascular magnetic resonance and speckle-tracking echocardiography

Left ventricular global longitudinal strain (LVGLS) analysis is a sensitive measurement of myocardial deformation most often done using speckle-tracking transthoracic echocardiography (TTE). We propose a novel approach to measure LVGLS using feature-tracking software on the magnitude dataset of 4D flow cardiovascular magnetic resonance (CMR) and compare it to dynamic computed tomography (CT) and speckle tracking TTE derived measurements. In this prospective cohort study 59 consecutive adult patients with a bicuspid aortic valve (BAV) were included. The study protocol consisted of TTE, CT, and CMR on the same day. Image analysis was done using dedicated feature-tracking (4D flow CMR and CT) and speckle-tracking (TTE) software, on apical 2-, 3-, and 4-chamber long-axis multiplanar reconstructions (4D flow CMR and CT) or standard apical 2-, 3-, and 4-chamber acquisitions (TTE). CMR and CT GLS analysis was feasible in all patients. Good correlations were observed for GLS measured by CMR (− 21 ± 3%) and CT (− 20 ± 3%) versus TTE (− 20 ± 3%, Pearson’s r: 0.67 and 0.65, p < 0.001). CMR also correlated well with CT (Pearson’s r 0.62, p < 0.001). The inter-observer analysis showed moderate to good reproducibility of GLS measurement by CMR, CT and TTE (Pearsons’s r: 0.51, 0.77, 0.70 respectively; p < 0.05). Additionally, ejection fraction (EF), end-diastolic and end-systolic volume measurements (EDV and ESV) correlated well between all modalities (Pearson’s r > 0.61, p < 0.001). Feature-tracking GLS analysis is feasible using the magnitude images acquired with 4D flow CMR. GLS measurement by CMR correlates well with CT and speckle-tracking 2D TTE. GLS analysis on 4D flow CMR allows for an integrative approach, integrating flow and functional data in a single sequence. Not applicable, observational study.

Diagnosis and Management of Patients with Heart Failure with Preserved Ejection Fraction (HFpEF): Current Perspectives and Recommendations

Heart failure with preserved ejection fraction (HFpEF) is a major global public health problem. Diagnosis of HFpEF is still challenging and built based on the comprehensive echocardiographic analysis. Currently, there are no universally accepted therapies that alter the clinical course of HFpEF. This review attempts to summarize the current advances in the diagnosis of HFpEF and provide future directions of the patients´ management with this very widespread, heterogeneous clinical syndrome.

The year 2018 in the European Heart Journal-Cardiovascular Imaging: Part II

European Heart Journal - Cardiovascular Imaging was launched in 2012 as a multimodality cardiovascular imaging journal. It has gained an impressive impact factor during its first 5 years and is now established as one of the top cardiovascular journals and has become the most important cardiovascular imaging journal in Europe. The most important studies from 2018 will be highlighted in two reports. Part I of the review has focused on studies about myocardial function and risk prediction, myocardial ischaemia, and emerging techniques in cardiovascular imaging, while Part II will focus on cardiomyopathies, congenital heart diseases, valvular heart diseases, and heart failure.

Evaluation of elevated left ventricular end diastolic pressure in patients with preserved ejection fraction using cardiac magnetic resonance

OBJECTIVES

This study aims to validate the reliability of cardiac magnetic resonance (CMR) parameters for estimating left ventricular end diastolic pressure (LVEDP) in heart failure patients with preserved ejection fraction (HFpEF) and compare their accuracy to conventional echocardiographic ones, with reference to left heart catheterisation.

METHODS

Sixty patients with exertional dyspnoea (New York Heart Association function class II to III) were consecutively enrolled. CMR-derived time-volume curve and deformation parameters, conventional echocardiographic diastolic indices as well as LVEDP evaluated by left heart catheterisation were collected and analysed.

RESULTS

Fifty-one patients, who accomplished all three examinations, were divided into HFpEF group and non-HFpEF group based on LVEDP measurements. Compared to the non-HFpEF group, CMR-derived time-volume curve showed lower peak filling rate adjusted for end diastolic volume (PFR/EDV, p = 0.027), longer time to peak filling rate (T-PFR, p < 0.001), and increased T-PFR in one cardiac cycle (%T-PFR, p < 0.001) in HFpEF group. In multivariable linear regression analysis, %T-PFR (β = 0.372, p = 0.024), left ventricular global peak longitudinal diastolic strain rate (LDSR, β = -0.471, p = 0.006), and E/e' (β = 0.547, p = 0.001) were independently associated with invasively measured LVEDP. The sensitivity and specificity of E/e' and LDSR for predicting the elevated LVEDP were 76%, 92% and 76%, 89%, respectively.

CONCLUSIONS

These findings suggest that CMR-derived time-volume curve and strain indices could predict HFpEF patients. Not only E/e' assessed by echocardiography but also the CMR-derived %T-PFR and LDSR correlated well with LVEDP. These non-invasive parameters were validated to evaluate the left ventricular diastolic function.

KEY POINTS

• The abnormal time-volume curve revealed insufficient early diastole in HFpEF patients. • Non-invasive parameters including E/e', %T-PFR, and LDSR correlated well with LVEDP.

Influence of age and sex on left ventricular diastolic strain analysis

Speckle tracking analysis (STE) of the left ventricle offers a new method to assess left ventricular (LV) diastolic function. LV diastolic strain measurements offer a non-invasive, global and direct measure of LV diastolic function. However, there is little data on normal values and the influence of anthropomorphic factors which is crucial in clinical practice for new techniques. The aims of this study were to formulate reference values for LV diastolic strain rate, elucidate effects of age and sex on LV diastolic strain analysis and compare STE measurements with conventional LV diastolic measurements. One-hundred-forty-seven healthy subjects aged 20–72 years (≥ 28 subjects per age decade) were prospectively included (Mean age 44 ± 13.7 years, 50% female) and examined with electrocardiography and 2D-echocardiography, including speckle tracking. Left ventricular peak early diastolic strain rate (Sre) was measured in the apical windows, using STE. Men had significantly lower LV Sre values than women (1.02 ± 0.22 vs. 1.18 ± 0.23, p value < 0.001). Left ventricular Sre was inversely associated with age, with values decreasing with ageing. An inverse relation was also found with blood pressure and body surface area. Linear regression analysis showed that LV Sre was independently associated with both age and sex. A multivariable linear regression analysis for LV Sre with conventional LV diastolic variables accounted for 70.9% of the variation of LV Sre, showing good model performance. Reference values for LV Sre are reported and found to be both age- and sex-dependent. Therefore we recommend age- and sex-specific references values to be used in daily clinical practice.