Noninvasive Assessment of Wall Distensibility With the Evaluation of Diastolic Epicardial Movement

Left Ventricular Wall Stress and Incident Heart Failure in Elderly Community-Dwelling Individuals

Background

Greater left ventricular (LV) wall stress is associated with adverse outcomes among patients with prevalent heart failure (HF). Less is known about the association between LV wall stress and incident HF.

Objectives

The purpose of the study was to identify clinical factors associated with wall stress and test the association between wall stress and incident HF.

Methods

We studied 4,601 ARIC (Atherosclerosis Risk In Communities) study participants without prevalent HF who underwent echocardiography between 2011 and 2013. LV end systolic and diastolic wall stress (LVESWS, LVEDWS) were calculated from chamber and wall thickness, systemic blood pressure, and transmitral Doppler E/e' as a surrogate for LV end diastolic pressure. Incident HF was ascertained by International Classification of Diseases (ICD)-9/10 claims for hospitalized HF through December 31, 2016. We used Cox regression to test the association between wall stress and incident HF, adjusted for demographics, traditional cardiovascular risk factors, prevalent coronary artery disease and atrial fibrillation, creatinine, N-terminal pro-B-type natriuretic peptide, troponin, triglycerides, C-reactive protein, LV ejection fraction, and LV mass.

Results

The cohort had a median age of 75 years and 58% women, with 18% identifying as Black. Median LVESWS and LVEDWS were 48.8 (25th-75th percentile: 39.3-60.1) and 18.9 (25th-75th percentile: 15.8-22.5) kdynes/cm2, respectively. LVESWS and LVEDWS were modestly related (rho = 0.30, P < 0.001). Over 4.6 years of median follow-up (156 HF events), each 1 kdyne/cm2 greater LVEDWS was significantly associated with higher risk of incident HF (HR: 1.03; 95% CI: 1.01-1.06), while LVESWS was not (HR: 1.00; 95% CI: 0.99-1.01).

Conclusions

Among community-dwelling elderly individuals, greater LVEDWS is associated with a higher risk for incident HF.

Incremental value of diastolic wall strain in predicting heart failure events in patients with atrial fibrillation

Diastolic wall strain (DWS), an echocardiographic index based on linear elasticity theory, has been identified as a predictor of heart failure (HF) in patients with sinus rhythm. However, its effectiveness in atrial fibrillation (AF) patients remains uncertain. This study aims to assess DWS as a predictor of HF in AF patients with preserved ejection fraction. We analysed a prospective database of AF patients undergoing transthoracic echocardiography. AF patients with reduced left ventricular ejection fraction (< 50%), posterior wall motion abnormality, hypertrophic cardiomyopathy, valvular heart disease, pericardial disease, congenital heart disease, or history of pacemaker/implantable cardioverter-defibrillator implantation or cardiac surgery were excluded. The study followed patients until HF development, death, or last visit. Follow-up for patients who underwent catheter ablation was censored on the date of their procedure. HF was ascertained based on the Framingham criteria. DWS was calculated using a validated formula: DWS = (PWs -PWd)/PWs, where PWs is the posterior wall thickness at end-systole and PWd is the posterior wall thickness at end-diastole. Among 411 study patients (mean age 69.6 years, 66% men), 20 (5%) was underwent catheter ablation and 57 (14%) developed HF during a mean follow-up of 82 months. Cox-proportional hazards demonstrated that low DWS (≤ 0.33) significantly predicted HF events (hazard ratio [HR] 3.28, 95% confidence interval [CI]) 1.81-5.94, P < 0.0001), independent of age (per 10 years; HR 1.99, 95% CI 1.35-2.93, P < 0.001), indexed left ventricular mass (per 10 g/m2; HR 1.16, 95% CI 1.05-1.27, P < 0.01), and indexed left atrial volume (per 10 mL/m2; HR 1.14, 95% CI 1.04-1.24, P < 0.01). Additionally, global log-likelihood ratio chi-square statistics indicated that DWS incrementally predicts HF development beyond age, indexed left ventricular mass, and left atrial volume (P < 0.001).

Evaluation of the relationship between left atrial stiffness, left ventricular stiffness, and left atrioventricular coupling index in type 2 diabetes patients: a speckle tracking echocardiography study

Background

Cardiovascular complications are a leading cause of mortality and disability in individuals with diabetes mellitus (DM). Moreover, DM can directly impact the structure and function of cardiac muscle. We conducted a study to evaluate cardiac stiffness in DM patients in both the left atrium (LA) and left ventricle (LV), as well as to assess the impact of DM on the synchronization of the LA and LV, particularly within the Vietnamese population, utilizing speckle tracking echocardiography (STE).

Methods

We studied 111 research subjects divided into two groups comprising 52 patients with DM and 59 healthy individuals. All the subjects provided relevant clinical information, and echocardiography was performed to assess the indices of LA stiffness, LV stiffness, and left atrioventricular coupling index (LACI).

Results

Our study indicated that DM patients exhibited greater LA and LV stiffness than control patients. The LACI (%) in the DM group was also greater than that in the control group (17.12% ± 6.72% vs. 12.28% ± 3.96%, respectively; p < 0.001). The LACI was positively correlated with the LA and LV stiffness indices. Decreased levels of LV GLS, adjusted for age, sex, blood pressure, and BMI, have emerged as identified risk factors for DM.

Conclusions

LA stiffness, LV stiffness, and the LACI are greater in DM patients than in normal individuals.

Evaluation of left ventricular stiffness with echocardiography

Half of patients with heart failure are presented with preserved ejection fraction (HFpEF). The pathophysiology of these patients is complex, but increased left ventricular (LV) stiffness has been proven to play a key role. However, the application of this parameter is limited due to the requirement for invasive catheterization for its measurement. With advances in ultrasound technology, significant progress has been made in the noninvasive assessment of LV chamber or myocardial stiffness using echocardiography. Therefore, this review aims to summarize the pathophysiological mechanisms, correlations with invasive LV stiffness constants, applications in different populations, as well as the limitations of echocardiography-derived indices for the assessment of both LV chamber and myocardial stiffness. Indices of LV chamber stiffness, such as the ratio of E/e' divided by left ventricular end-diastolic volume (E/e'/LVEDV), the ratio of E/SRe (early diastolic strain rates)/LVEDV, and diastolic pressure-volume quotient (DPVQ), are derived from the relationship between echocardiographic parameters of LV filling pressure (LVFP) and LV size. However, these methods are surrogate and lumped measurements, relying on E/e' or E/SRe for evaluating LVFP. The limitations of E/e' or E/SRe in the assessment of LVFP may contribute to the moderate correlation between E/e'/LVEDV or E/SRe/LVEDV and LV stiffness constants. Even the most validated measurement (DPVQ) is considered unreliable in individual patients. In comparison to E/e'/LVEDV and E/SRe/LVEDV, indices like time-velocity integral (TVI) measurements of pulmonary venous and transmitral flows may demonstrate better performance in assessing LV chamber stiffness, as evidenced by their higher correlation with LV stiffness constants. However, only one study has been conducted on the exploration and application of TVI in the literature, and the accuracy of assessing LV chamber stiffness remains to be confirmed. Regarding echocardiographic indices for LV myocardial stiffness evaluation, parameters such as epicardial movement index (EMI)/ diastolic wall strain (DWS), intrinsic velocity propagation of myocardial stretch (iVP), and shear wave imaging (SWI) have been proposed. While the alteration of DWS and its predictive value for adverse outcomes in various populations have been widely validated, it has been found that DWS may be better considered as an overall marker of cardiac function performance rather than pure myocardial stiffness. Although the effectiveness of iVP and SWI in assessing left ventricular myocardial stiffness has been demonstrated in animal models and clinical studies, both indices have their limitations. Overall, it seems that currently no echocardiography-derived indices can reliably and accurately assess LV stiffness, despite the development of several parameters. Therefore, a comprehensive evaluation of LV stiffness using all available parameters may be more accurate and enable earlier detection of alterations in LV stiffness.

Association Between Endothelial Dysfunction and Left Ventricular Diastolic Stiffness - Subanalysis of the Flow-Mediated Dilation Japan (FMD-J) Study

BACKGROUND

Endothelial dysfunction and increased left ventricular (LV) stiffness are associated with the incidence of heart failure with preserved ejection fraction (HFpEF). This study evaluated the association between endothelial dysfunction and LV diastolic stiffness.

METHODS AND RESULTS

Endothelial dysfunction evaluated by flow-medicated vasodilation (FMD) and the reactive hyperemia index (RHI), which reflects endothelial dysfunction in the microvasculature, was measured in 112 subjects with hypertension in the Flow-Mediated Dilation Japan (FMD-J) study. Using transthoracic echocardiography, LV diastolic stiffness was evaluated by measuring diastolic wall strain (DWS) in the LV posterior wall. In this cross-sectional study, associations among FMD, RHI, and DWS were investigated using multiple regression analyses. The mean (±SD) age of the subjects 65±9 years, and 63% were men. DWS was significantly associated with RHI, but not FMD, on multivariate linear regression analysis (β=0.39; P<0.0001). This association was preserved in subjects without LV hypertrophy (β=0.46; P<0.0001). A DWS ≤median, suggesting increased LV diastolic stiffness, was significantly associated with RHI on multivariate logistic regression analysis (odds ratio 20.58; 95% confidence interval 4.83-87.63; P<0.0001). The receiver operating characteristic curve presented a cut-off value of 2.21 for RHI, with a sensitivity of 77% and a specificity of 71%, for DWS ≤median.

CONCLUSIONS

RHI, rather than FMD, was associated with DWS. Endothelial dysfunction in the microvasculature may be associated with increased LV diastolic stiffness.

Paradoxical increase in global longitudinal strain by handgrip exercise despite left ventricular diastolic dysfunction

BACKGROUND

Although global longitudinal strain (GLS) is recognized as a sensitive marker of intrinsic left ventricular (LV) dysfunction, its afterload dependency has also been pointed. We hypothesized that decrease in GLS during handgrip exercise could be more sensitive marker of intrinsic myocardial dysfunction.

METHODS

Handgrip exercise-stress echocardiography was performed in 90 cardiovascular disease patients with preserved LV ejection fraction. LV diastolic function was graded according to the guidelines. Diastolic wall stress (DWS) and ratio of left atrial (LA) volume index to late-diastolic mitral annular velocity (LAVI/a') were measured at rest as LV stiffness. As well, LA strains were measured to assess LA function. GLS was expressed as absolute value and significant changes in GLS by handgrip exercise was defined as changes over prespecified mean absolute test-retest variability (2.65%).

RESULTS

While mean value of GLS did not change by the exercise, substantial patients showed significant changes in GLS: decreased (group I, n = 28), unchanged (group II, n = 34), and increased (group III, n = 28). Unexpectedly, patients in group I did not show any clinical and echocardiographic characteristics, while those in group III were characterized by elevated natriuretic peptide levels, blunted heart rate response to handgrip exercise, and advanced LV diastolic dysfunction. Multivariable analyses revealed that DWS, left atrial booster strain, and grade II or more diastolic dysfunction determined the increase in GLS even after adjustment for elevated natriuretic peptides and the changes in heart rate by the exercise.

CONCLUSION

In contrast to our hypothesis, paradoxical increase in GLS by handgrip exercise could be associated with advanced LV diastolic dysfunction in cardiovascular patients with preserved LV ejection fraction. Our findings suggest that HG exercise for heart failure patients does not enhance the afterload straightforward, resulting in variable changes of GLS according to the individual conditions.

Lifetime Evaluation of Left Ventricular Structure and Function in Male C57BL/6J Mice after Gamma and Space-Type Radiation Exposure

The lifetime effects of space irradiation (IR) on left ventricular (LV) function are unknown. The cardiac effects induced by space-type IR, specifically 5-ion simplified galactic cosmic ray simulation (simGCRsim), are yet to be discovered. Three-month-old, age-matched, male C57BL/6J mice were irradiated with 137Cs gamma (γ; 100, 200 cGy) and simGCRsim (50 and 100 cGy). LV function was assessed via transthoracic echocardiography at 14 and 28 days (early), and at 365, 440, and 660 (late) days post IR. We measured the endothelial function marker brain natriuretic peptide in plasma at three late timepoints. We assessed the mRNA expression of the genes involved in cardiac remodeling, fibrosis, inflammation, and calcium handling in LVs harvested at 660 days post IR. All IR groups had impaired global LV systolic function at 14, 28, and 365 days. At 660 days, 50 cGy simGCRsim-IR mice exhibited preserved LV systolic function with altered LV size and mass. At this timepoint, the simGCRsim-IR mice had elevated levels of cardiac fibrosis, inflammation, and hypertrophy markers Tgfβ1, Mcp1, Mmp9, and βmhc, suggesting that space-type IR may induce the cardiac remodeling processes that are commonly associated with diastolic dysfunction. IR groups showing statistical significance were modeled to calculate the Relative Biological Effectiveness (RBE) and Radiation Effects Ratio (RER). The observed dose-response shape did not indicate a lower threshold at these IR doses. A single full-body IR at doses of 100-200 cGy for γ-IR, and 50-100 cGy for simGCRsim-IR decreases the global LV systolic function in WT mice as early as 14 and 28 days after exposure, and at 660 days post IR. Interestingly, there is an intermediate time point (365 days) where the impairment in LV function is observed. These findings do not exclude the possibility of increased acute or degenerative cardiovascular disease risks at lower doses of space-type IR, and/or when combined with other space travel-associated stressors such as microgravity.

Can we explore AF-pacemakers' relationship using clinical and echocardiographic parameters in patients with permanent pacemaker? (Echocardiography and subclinical AF in permanent pacemaker)

Patients on implanted permanent pacemakers frequently develop atrial fibrillation (AF). We aimed to determine the Echocardiographic and clinical parameters predicting AF in patients with a dual-chamber (DDD) pacemaker. This retrospective study included 208 patients with permanent pacemaker, classified according to development of AF during follow up into 2 groups: AF (77, 37%) and non AF (131, 63%), baseline: clinical, ECG(P-wave dispersion) and echo {diastolic wall strain (DWS),left arial volume index (LAVI), left ventricular stiffness index(LVSI)} data were assessed. AF group were older with more P wave dispersion, lesser DWS, greater LVSI& LAVI, LVSI at a cut off > 0.13 and DWS at a cut off < 0.34 were predictors of AF in patients with DDD pacemakers. LVSI and DWS could be used as simple good predictors for AF in patients with DDD pacemakers, for timely initiation of anticoagulants according to CHA₂DS₂VASc score to decrease ischemic stroke burden.

Comprehensive assessment of systemic arteriosclerosis in relation to the ocular resistive index in acute coronary syndrome patients

This study aimed to investigate the relationship between ocular vascular resistance parameters, evaluated by laser speckle flowgraphy (LSFG), and systemic atherosclerosis, renal parameters and cardiac function in acute coronary syndrome (ACS) patients. We evaluated 53 ACS patients between April 2019 and September 2020. LSFG measured the mean blur rate (MBR) and ocular blowout time (BOT) and resistivity index (RI). 110 consequent patients without a history of coronary artery disease who visited ophthalmology as a control group. Significant positive correlations were observed between ocular RI and systemic parameters in ACS patients, including intima-media thickness (r = 0.34, P = 0.015), brachial-ankle pulse-wave velocity (r = 0.41, P = 0.002), cystatin C (r = 0.32, P = 0.020), and E/e’ (r = 0.34, P = 0.013). Ocular RI was significantly higher in the ACS group than in the control group in male in their 40 s (0.37 ± 0.02 vs. 0.29 ± 0.01, P < 0.001) and 50 s (0.36 ± 0.02 vs. 0.30 ± 0.01, P = 0.01). We found that the ocular RI was associated with systemic atherosclerosis, early renal dysfunction, and diastolic cardiac dysfunction in ACS patients, suggesting that it could be a useful non-invasive comprehensive arteriosclerotic marker.

AV timing in pacemaker patients with first-degree AV block: which is preferable, intrinsic AV conduction or pacing?

Some patients with pacemakers present with first-degree atrioventricular (AV) block. To avoid right ventricular (RV) pacing, preserving intrinsic AV conduction as much as possible is recommended. However, there is no clear cutoff AV interval to determine whether intrinsic AV conduction should be preserved or RV pacing should be delivered. This study aimed to compare a pacing mode-preserving, intrinsic AV conduction with the DDD mode delivering RV pacing in terms of echocardiographic parameters in patients with first-degree AV block and to investigate whether RV pacing induces heart failure (HF). Stroke volume (SV) was measured to determine the optimal AV delay with the intrinsic AV conduction rhythm and the DDD pacing delivering RV pacing. Echocardiographic evaluation was performed for 6-month follow-up period. Seventeen patients were studied. At baseline, mean intrinsic PQ interval was 250 ± 40 ms. SV was greater with RV pacing with optimal AV delay of 160 ms than with intrinsic AV conduction rhythm in all patients. Therefore, pacemakers were set to the DDD to deliver RV pacing. During follow-up, seven patients developed HF. Mean baseline E/E′ ratio in patients who developed HF (HF group) during RV pacing was higher than in patients without HF (non = HF group; 17.9 ± 8 versus 11.5 ± 2, P = 0.018) Even within HF group patients without a high baseline E/E′ ratio, it increased with RV pacing (22.2 ± 6 versus 11.6 ± 2; P < 0.001). In patients with pacemaker and first-degree AV block, RV pacing with the optimal AV delay of 160 ms increased SV. However, the risk of HF may be increased with RV pacing if the E/Eʹ ratio is > 15 during intrinsic AV conduction or RV pacing. RV pacing should be avoided in patients with high E/Eʹ ratio under intrinsic AV conduction or RV pacing.

Amplifying effect of chronic lisinopril therapy on diastolic function and the angiotensin-(1-7) Axis by the G1 agonist in ovariectomized spontaneously hypertensive rats

G protein-coupled estrogen receptor (GPER) activation by G1 attenuates diastolic dysfunction from estrogen loss, which may be partly due to suppression of angiotensin II pathological actions. We aimed to determine the independent effects of 8 weeks of G1 (100 µg/kg/d, subcutaneous pellet), ACE-inhibition (ACEi; lisinopril 10 mg/kg, drinking water), or combination therapy versus vehicle in the ovariectomized (OVX) spontaneously hypertensive rat (SHR) on cardiac function and morphometrics (echocardiography), serum equilibrium of angiotensins (mass spectroscopy) and cardiac components of the RAS (Western blotting). G1 alone and when combined with ACEi enhanced myocardial relaxation (é: 30 and 17%) and diastolic wall strain (DWS: 76 and 68%) while reducing relative wall thickness (RWT: 20 and 33%) and filling pressures (E/é: 30 and 37%). Cardiac expression levels of Mas receptor (Mas-R) and ACE2 also increased in the presence of G1. Strong antihypertensive effects of lisinopril monotherapy were associated with reductions in RWT, collagen deposition and E/é without overtly altering é or DWS. Chronic ACEi also increased cardiac levels of Mas-R and AT₁-R and tilted the circulating RAS toward the formation of Ang-(1-7), which was amplified in the presence of G1. In vitro studies further revealed that an inhibitor to prolyl endopeptidase (PEP), but not to neprilysin, significantly reduced serum Ang-(1-7) levels in G1-treated rats, suggesting that G1 might be increasing Ang-(1-7) formation via PEP. We conclude that activating GPER with G1 augments components of the cardiac RAS and improves diastolic function without lowering blood pressure, and that lisinopril-induced blood pressure control and cardiac alterations in OVX SHR are permissive in facilitating G1 to augment Ang-(1-7) in serum, thereby strengthening its cardioprotective benefits.

Left ventricular stiffness assessed by diastolic Wall strain predicts asymptomatic atrial high-rate episodes in patients with pacemaker implantation

BACKGROUND

Cardiac implantable electronic device-detected atrial high-rate episodes (AHREs) have been reported to be associated with thromboembolic risks. The present study aimed to investigate the association of echocardiographic and clinical parameters with the occurrence of AHREs in patients with a dual-chamber pacemaker (PMI).

METHODS

One hundred forty-seven patients (76 males, 75.2 ± 8.9 years) who did not show atrial tachyarrhythmia before the implantation of the PMI were studied. Diastolic wall strain (DWS) and other measurements were assessed during sinus rhythm using transthoracic echocardiography before the PMI. DWS was calculated from the M-mode echocardiographic measurement of the left ventricular (LV) posterior wall thickness at end-systole (PWs) and end-diastole (PWd), and DWS was defined as (PWs-PWd) / PWs.

RESULTS

AHREs (defined as AHREs duration >6 min and atrial rate >180 bpm) were detected in 50 / 147 patients during follow up (38.3 ± 13.8 months). Patients in the AHREs group had reduced DWS (0.29 ± 0.07 vs. 0.39 ± 0.06, p < 0.0001), larger left atrial volume index, thicker LV posterior diameter, higher rate of patients taking β-blocker / diuretics, and higher prevalence of sinus node dysfunction. On multivariable analysis, only DWS was independently associated with AHREs. Patients with reduced DWS (<0.33) had a higher risk of incidences of AHREs.

CONCLUSION

LV stiffness assessed by DWS was associated with AHREs in patients with a PMI.

Impaired global longitudinal strain in elderly patients with preserved ejection fraction is associated with raised post-exercise left ventricular filling pressure

BACKGROUND

The purpose of this study was to evaluate whether impaired resting global longitudinal strain (GLS) in elderly patients with preserved left ventricular (LV) ejection fraction (EF) is associated with raised post-exercise LV filling pressure estimated by the ratio of early diastolic transmitral flow velocity to annulus velocity (E/e').

METHODS

Seventy elderly patients (age = 74 ± 6 years, male 40 patients) who underwent treadmill stress echocardiography were studied. All patients had normal sinus rhythm, normal LV wall motion at rest, and had preserved LVEF ≥ 50%. Patients with exercise induced wall motion abnormality were not included. GLS at rest was measured using automated functional imaging.

RESULTS

Twenty-four of the 70 patients had raised post-exercise LV filling pressure indicated by septal E/e' ≥ 15.0. Patients with raised post-exercise LV filling pressure had smaller resting GLS than that in patients without it (- 16.9 ± 1.8 vs. - 19.6 ± 2.5%, respectively, p < 0.0001). Downward stepwise multivariate logistic regression analysis demonstrated that resting GLS was one of independent predictors of raised post-exercise E/e'. Receiver operating characteristic (ROC) curve analysis had demonstrated that optimal cutoff point for resting GLS to predict raised post-exercise E/e' was - 17.8% (sensitivity 83.3%, specificity 80.4%, respectively), and the area under the ROC curve was 0.820.

CONCLUSION

In elderly patients with preserved LVEF and without obvious myocardial ischemia, impaired resting GLS at rest is associated with raised post-exercise LV filling pressure estimated by E/e' ≥ 15.0.

Association of renal resistance index and arterial stiffness on clinical outcomes in patients with mild-to-moderate renal dysfunction and presence or absence of heart failure with preserved ejection fraction

The renal arterial resistance index (RI) and the brachial-ankle pulse wave velocity (baPWV) are known as indicators of renal vascular resistance/systemic vascular damage and systemic arterial stiffness. The clinical significance of those parameters on clinical outcomes is poorly known in patients with and without heart failure with preserved ejection fraction (HFpEF). Baseline clinical data and the RI assessed by renal Doppler data, baPWV were obtained in patients with (HFpEF group, n = 60) and without HFpEF (non-HFpEF group, n = 51) who had a reduced estimated glomerular filtration rate (eGFR) of > 30 and < 60 mL/min/1.73 m²). We investigated the association between the RI and baPWV and major clinical outcomes including hospitalization for heart failure, cardiovascular death, myocardial infarction or unstable angina or other cardiovascular events and death from another cause. The RI and baPWV were greater in the HFpEF group than in the non-HF group (0.75 ± 0.07 vs. 0.69 ± 0.08, p < 0.001; 2002 ± 430 vs. 1762 ± 300 cm/s, p = 0.001). The RI correlated significantly with baPWV in the HFpEF (r = 0.382, p = 0.003) and non-HFpEF groups (r = 0.414, p = 0.002). During the median follow-up period of 54 months, major clinical outcomes occurred in 41 (36.9%) patients. The RI value, statin use and the presence of HFpEF were major factors for predicting clinical outcomes by multivariate analysis. Among the patients who had mild-to-moderate renal dysfunction, an increased RI and baPWV were observed in HFpEF patients as compared to non-HFpEF patients, but the baPWV similarly correlated with the RI value regardless of HFpFE patients or not. The strong association between the high RI value and presence of HFpEF and major clinical outcomes, suggests that not only the presence of HFpEF but also the high RI value may help to identify the high-risk patients leading to poor clinical outcomes.

Left ventricular stiffness in paediatric patients with end-stage kidney disease

BACKGROUND

We tested the hypothesis that myocardial stiffness is altered in paediatric patients with end-stage kidney disease (ESKD) and explored its association with clinical parameters of chronic kidney disease (CKD).

METHODS

Thirty-five patients with ESKD (16 males) aged 17.5 ± 3 years old, 18/35 of whom were receiving dialysis and 17 post kidney transplant, were studied. Left ventricular (LV) myocardial stiffness was determined by measurement of diastolic wall strain (DWS) and stiffness index (SI), while LV diastolic function was interrogated by pulsed-wave and tissue Doppler echocardiography.

RESULTS

Compared with available literature data, both dialysis and transplanted patients had significantly lower DWS and greater SI, reduced transmitral early (E) to late diastolic velocity ratio and septal and lateral mitral annular early (e') diastolic velocities, and greater septal and lateral E/e' ratios (all p < 0.05). Multivariate analysis revealed that z score of diastolic blood pressure (β = 0.43, p = 0.004) and the duration of renal replacement therapy (β = 0.55, p < 0.001) were significant determinants of LV SI. Subgroup analysis in post-transplant patients showed z score of diastolic blood pressure (β = 0.54, p = 0.025) remained as a significant determinant of LV SI.

CONCLUSION

Increased LV myocardial stiffness is evident in paediatric dialysis and transplanted patients with ESKD, and is associated with blood pressure and duration of renal replacement therapy.

Left Ventricular Stiffness in Adolescents and Young Adults After Arterial Switch Operation for Complete Transposition of the Great Arteries

We tested the hypothesis that left ventricular (LV) myocardial stiffness is altered in patients with transposition of great arteries (TGA) after arterial switch operation (ASO) and explored its associations with myocardial calibrated integrated backscatter (cIB) and LV myocardial deformation. Thirty-one patients and twenty-two age-matched controls were studied. LV myocardial stiffness was assessed by diastolic wall strain (DWS) and stiffness indices including (E/e)/LV end-diastolic dimension, (E/LV global longitudinal early diastolic strain rate)/LV end-diastolic volume, and (E/LV global circumferential early diastolic strain rate)/LV end-diastolic volume, where E and e are early diastolic transmitral and mitral annular velocities, respectively. LV myocardial cIB and longitudinal and circumferential myocardial deformation were determined by conventional and speckle tracking echocardiography. Patients had significantly lower DWS, higher stiffness indices, and greater myocardial cIB than controls (all p < 0.05). The LV longitudinal and circumferential systolic strain and systolic and diastolic strain rates were significantly lower in patients than controls (all p < 0.05). Greater average myocardial cIB was associated with lower DWS (r = - 0.44, p = 0.002). Worse DWS and LV stiffness indices were found to correlate with lower mitral annular systolic velocity, mitral annular late diastolic velocity, and LV longitudinal late diastolic strain rate (all p < 0.05). LV longitudinal and circumferential systolic strain and strain rate were also found to correlate with DWS (all p < 0.05). In conclusion, LV myocardial stiffening occurs in adolescents and young adults with TGA after ASO and is associated with impairment of ventricular systolic and diastolic myocardial deformation and myocardial fibrosis.

The role of M-mode echocardiography in patients with heart failure and preserved ejection fraction: A prospective cohort study

Epicardial movement during diastole is inversely proportional to myocardial stiffness but systolic regional thickening cannot precisely identify ischemic territories. The aim of the present study was to test the hypothesis that a correlation may be present between M-mode echocardiography parameters and poor outcomes in patients with heart failure and preserved ejection fraction. Patients with known cardiovascular disease were included in the test group (n=1,244) and patients without known cardiovascular disease were included in the control group (n=1,952). Patient records of routine measurements, M-mode echocardiography and mortality were collected. The control population and test population had the same left ventricular end-diastolic dimension (P=0.062) and left ventricular end-diastolic volume (P=0.053). A lower mitral flow velocity (P<0.05), higher Tei index (P<0.0001) and reduced distribution of diastolic wall strain (P<0.0001) were reported in the test populations compared with the control population. Patients of the test population with lower diastolic wall strain (<0.28) demonstrated a higher mortality rate than those with higher diastolic wall strain (≥0.28; P<0.0001) at the 3-year follow-up. M-mode echocardiographic parameters may be of use for predicting poor outcomes in patients with heart failure and preserved ejection fraction.

Speckle-tracking echocardiography combined with imaging mass spectrometry assesses region-dependent alterations

Left ventricular (LV) contraction is characterized by shortening and thickening of longitudinal and circumferential fibres. To date, it is poorly understood how LV deformation is altered in the pathogenesis of streptozotocin (STZ)-induced type 1 diabetes mellitus-associated diabetic cardiomyopathy and how this is associated with changes in cardiac structural composition. To gain further insights in these LV alterations, eight-week-old C57BL6/j mice were intraperitoneally injected with 50 mg/kg body weight STZ during 5 consecutive days. Six, 9, and 12 weeks (w) post injections, echocardiographic analysis was performed using a Vevo 3100 device coupled to a 30-MHz linear-frequency transducer. Speckle-tracking echocardiography (STE) demonstrated impaired global longitudinal peak strain (GLS) in STZ versus control mice at all time points. 9w STZ animals displayed an impaired global circumferential peak strain (GCS) versus 6w and 12w STZ mice. They further exhibited decreased myocardial deformation behaviour of the anterior and posterior base versus controls, which was paralleled with an elevated collagen I/III protein ratio. Additionally, hypothesis-free proteome analysis by imaging mass spectrometry (IMS) identified regional- and time-dependent changes of proteins affecting sarcomere mechanics between STZ and control mice. In conclusion, STZ-induced diabetic cardiomyopathy changes global cardiac deformation associated with alterations in cardiac sarcomere proteins.

Diastolic wall strain as a predictor of age-related cardiovascular events in patients with preserved left ventricular ejection fraction

Diastolic wall strain (DWS) was reported as a simple and feasible echocardiographic index in assessing left ventricular (LV) diastolic stiffness. We sought to evaluate whether DWS predicts age-related cardiovascular events. Patients referred for transthoracic echocardiogram, those with preserved LV ejection fraction and no clinical heart failure were studied. Cardiovascular events were ascertained using Framingham criteria (myocardial infarction, coronary insufficiency, stroke, transient ischemic attack, congestive heart failure, or cardiovascular death). DWS was calculated with a validated formula. Cox proportional hazards modeling was used to assess the risk of cardiovascular events. Of a total number of 962 patients (mean age 60.9 ± 14.9 years, 48.0% men), 69 (7.2%) developed at least 1 cardiovascular event during a mean follow-up of 43 ± 32 months. After adjusting for cardiovascular comorbidities in a multivariable model, low DWS (≦ 0.33) was a significant independent predictor of cardiovascular events [hazard ratio (HR): 1.87, 95% confidential interval (CI) 1.04-3.36, P = 0.04]. Echocardiographic assessment of DWS may help in identifying the patients at increased risk for future age-related cardiovascular events.

Elevated serum osteoprotegerin is associated with increased left ventricular mass index and myocardial stiffness

AIM

Osteoprotegerin (OPG) is associated with a poor prognosis in patients with heart failure with preserved ejection fraction (HFpEF). OPG has also been associated with fibrosis and collagen cross-linking, which increase arterial and left ventricle (LV) myocardial stiffness. Little is known about the relation of OPG and LV structure and function in African-Americans who are disproportionately affected by HFpEF.

METHODS AND RESULTS

Our analysis included 1172 participants with preserved LV ejection fraction (>50%) from the African-American cohort in the Genetic Epidemiology Network of Arteriopathy Study (mean age 63 years, 72% female). We used diastolic wall strain indicator measured by echocardiography to assess LV myocardial stiffness. Diastolic wall strain was calculated as (LV posterior thickness at end-systole - LV posterior thickness at end-diastole)/LV posterior thickness at end-systole. Associations between OPG levels and indices of arterial and LV structure and function were evaluated by using generalized linear mixed models and adjusted for possible confounders. OPG levels were correlated with age, female sex, presence of hypertension and diabetes, and lower estimated glomerular filtration rate (P < 0.05 for all). Multivariable analysis revealed that higher OPG levels were associated with greater LV mass index, increased LV myocardial stiffness, and higher N-terminal prohormone brain natriuretic peptide levels (P < 0.05 for all).

CONCLUSION

In African-Americans, higher OPG levels were associated with characteristics common in patients with HFpEF and were significantly associated with known precursors to HFpEF. These findings indicate a potential role for OPG in the pathophysiology of HFpEF in African-Americans.

Higher plasma leptin levels are associated with reduced left ventricular mass and left ventricular diastolic stiffness in black women: insights from the Genetic Epidemiology Network of Arteriopathy (GENOA) study

Our previous experimental animal data suggest a beneficial effect of leptin on LV structure and function. We hypothesized that leptin levels are associated with lower LV mass and myocardial stiffness which are important risk factors for the development of heart failure with preserved ejection fraction (HFpEF). We evaluated 1172 blacks, in which the prevalence of HFpEF is quite high, with preserved LV ejection fraction (EF > 50%) from the Genetic Epidemiology Network of Arteriopathy Study (mean age 62.9 years, 72% women), a community-based study to identify genes influencing blood pressure and target organ damage due to hypertension. Associations between leptin levels and indices of LV structure and function were evaluated using generalized estimating equations accounting for clustering in siblings. LV myocardial stiffness was evaluated using diastolic wall strain (DWS) measured by echocardiography. Analyses were stratified by sex because leptin levels were three times higher in women than men (p < 0.001). After adjustment for confounders, higher leptin levels were associated with lower LV mass (coefficient for 1 s.d. increase of leptin level: -5.825 g, 95% CI: -9.755 to -1.895 g, P = 0.004) and higher DWS (lower LV stiffness) (coefficient for 1 s.d. increase of leptin level: 0.009, 95% CI: 0.002-0.015, P = 0.007) in women. There were no statistically significant associations in men. In women, there were interactions between leptin levels and body mass index quartiles on LV mass and stiffness (p < 0.05 for both). Higher leptin levels were associated with lower LV mass and stiffness in obese but not lean black women.

Diastolic wall strain is associated with incident heart failure in African Americans: Insights from the atherosclerosis risk in communities study

BACKGROUND

Increased left ventricular (LV) myocardial stiffness may be associated with impaired LV hemodynamics and incident heart failure (HF). However, an indicator that estimates LV myocardial stiffness easily and non-invasively is lacking. The purpose of this study was to determine whether diastolic wall strain (DWS), an echocardiographic estimator of LV myocardial stiffness, is associated with incident HF in a middle-aged community-based cohort of African Americans.

METHODS AND RESULTS

We investigated associations between DWS and incident HF among 1528 African Americans (mean age 58.5 years, 66% women) with preserved LV ejection fraction (EF ≥50%) and without a history of cardiovascular disease in the Atherosclerosis Risk in Communities Study. Participants with the smallest DWS quintile (more LV myocardial stiffness) had a higher LV mass index, higher relative wall thickness, and lower arterial compliance than those in the larger four DWS quintiles (p<0.01 for all). Over a mean follow-up of 15.6 years, there were 251 incident HF events (incidence rate: 10.9 per 1000 person-years). After adjustment for traditional risk factors and incident coronary artery disease, both continuous and categorical DWS were independently associated with incident HF (HR 1.21, 95%CI 1.04-1.41 for 0.1 decrease in continuous DWS, p=0.014, HR 1.40, 95%CI 1.05-1.87 for the smallest DWS quintile vs other combined quintiles, p=0.022).

CONCLUSIONS

DWS was independently associated with an increased risk of incident HF in a community-based cohort of African Americans. DWS could be used as a qualitative estimator of LV myocardial stiffness.

Myocardial stiffness as assessed by diastolic wall strain in adult survivors of childhood leukaemias with preserved left ventricular ejection fraction

Aims

We tested the hypothesis that myocardial stiffness as assessed by diastolic wall strain (DWS) is altered in adult survivors of childhood leukaemias with preserved left ventricular (LV) ejection fraction and explored its association with myocardial fibrosis and diastolic deformation.

Methods and results

Ninety-four (53 males) adult survivors of childhood leukaemias aged 22.2 ± 5.5 years and 66 (36 males) healthy controls were studied retrospectively. Diastolic wall strain and calibrated integrated backscatter (cIB) were measured as indices of myocardial stiffness and fibrosis, respectively. Left and right ventricular (RV) diastolic and torsional mechanics were interrogated using speckle tracking echocardiography. Patients had significantly lower LV DWS, and hence stiffer LV myocardium, and greater myocardial cIB in patients than controls (all P < 0.001). Left ventricular longitudinal, radial, and circumferential early diastolic strain rates, circumferential late diastolic strain rate, and peak twisting and untwisting velocities, tricuspid annular early diastolic velocity, and RV-free wall longitudinal early diastolic strain rate were significantly lower in patients than controls (all P < 0.05). Diastolic wall strain correlated inversely with myocardial cIB, and positively with LV longitudinal, radial, and circumferential early diastolic strain rates (all P < 0.05), while myocardial cIB correlated inversely with LV radial and circumferential early diastolic strain rates, circumferential late diastolic strain rate, peak twisting and untwisting velocities, and tricuspid annular e velocity (all P < 0.05).

Conclusion

In adult survivors of childhood leukaemias, despite the preservation of LV ejection fraction, increased stiffness of the LV myocardium is evident and is associated with myocardial fibrosis and impaired ventricular diastolic function.

Lower diastolic wall strain is associated with coronary revascularization in patients with stable angina

Background

Left ventricular (LV) diastolic dysfunction occurs earlier in the ischemic cascade than LV systolic dysfunction and electrocardiographic changes. Diastolic wall strain (DWS) has been proposed as a marker of LV diastolic stiffness. Therefore, the objectives of this study were to define the relationship between DWS and coronary revascularization and to evaluate other echocardiographic parameters in patients with stable angina who were undergoing coronary angiography (CAG).

Methods

Four hundred forty patients [mean age: 61 ± 10; 249 (57%) men] undergoing CAG and with normal left ventricular systolic function without regional wall motion abnormalities were enrolled. Among them, 128 (29%) patients underwent revascularization (percutaneous intervention: 117, bypass surgery: 11). All patients underwent echocardiography before CAG and the DWS was defined using posterior wall thickness (PWT) measurements from standard echocardiographic images [DWS = PWT(systole)-PWT(diastole)/PWT(systole)].

Results

Patients who underwent revascularization had a significantly lower DWS than those who did not (0.26 ± 0.08 vs. 0.38 ± 0.09, p < 0.001). Age was comparable between the two groups (61 ± 9 vs. 60 ± 11, p = 0.337), but the proportion of males was significantly higher among patients who underwent revascularization (69 vs. 52%, p = 0.001). The LV ejection fraction was similar but slightly decreased (60.9 ± 5.7 vs. 62.4 ± 6.2%, p = 0.019) and the E/E’ ratio was elevated (10.3 ± 4.0 vs. 9.0 ± 3.1, p < 0.001) among patients who underwent revascularization. In multiple regression analysis, lower DWS was an independent predictor of revascularization (cut-off value: 0.34; sensitivity: 89%; AUC: 0.870; SE: 0.025; p < 0.001).

Conclusion

DWS, a simple parameter that can be calculated from routine 2D echocardiography, is inversely associated with the presence of coronary artery disease and the need for revascularization.

Predictors of Prognosis in Light-Chain Amyloidosis and Chronological Changes in Cardiac Morphology and Function

Immune light-chain (AL) amyloidosis with cardiac involvement is associated with a high mortality despite improved therapeutic regimens, but there are few reports on prognostic predictors and chronological changes in cardiac morphology and function. Prognosis and its predictors were evaluated in 36 consecutive patients with cardiac AL amyloidosis. Chronological changes in cardiac morphology and function were also evaluated. The median follow-up period was 0.95 years. The median survival time and the 3-year death-free rate after diagnosis in all-cause and cardiac deaths were 0.85 and 1.06 years and 26% and 36%, respectively. Differences in the median survival time due to left ventricular (LV) wall thickness at diagnosis were not evident. Being female and diastolic wall strain (DWS), as a measure of diastolic stiffness, were independent predictors of all-cause death in the multivariable analysis. The receiver operating characteristic analysis revealed that a DWS cut-off value of 0.189 had a sensitivity of 78% and a specificity of 72% for predicting all-cause death within 1 year after diagnosis (area under the curve = 0.726). The LV size and the stroke volume decreased and DWS worsened during the short-term follow-up period in patients who died within 1 year compared with patients who were alive after 1 year. The prognosis for patients with cardiac AL amyloidosis was poor, and DWS may be a significant predictor of prognosis. Narrowing of the LV cavity and progressive diastolic dysfunction were evident in patients with a poor prognosis.

Sustained Activation of Guanylate Cyclase-A with TDT, a Natriuretic Peptide Derivative, Exhibits Cardiorenal Protection in Dahl Salt-Sensitive Hypertensive Rats

Heart failure often presents with prognosis-relevant impaired renal function. To investigate whether the chronic activation of guanylate cyclase-A (GC-A) protects both heart and kidney, we examined the effects of TDT, a neprilysin (NEP)-resistant natriuretic peptide (NP) derivative, on cardiac and renal dysfunction in Dahl salt-sensitive hypertensive (DS) rats. Pretreatment with NEP or NEP inhibitor did not influence GC-A activation by TDT both in vitro and in vivo, resulting in a long-acting profile of TDT compared with native human atrial NP (hANP). The repeated administration of TDT to DS rats suppressed the progress of cardiac hypertrophy, systolic/diastolic dysfunction, and proteinuria in a dose-dependent manner. Compared with vehicle and hANP, salt diet-induced podocyte injury was reduced by TDT, as analyzed by urinary podocalyxin concentration, renal expression of nephrin mRNA, and glomerular expression of desmin protein. Since glomerular TRPC6 plays detrimental roles in podocyte homeostasis, we examined the renal expression of TRPC6 in DS rats and found that salt diet upregulated the expression of TRPC6. Importantly, TRPC6 induction was significantly decreased in TDT-treated rats, compared with vehicle and hANP. Consistently, in primary-culture podocytes from DS rats, TDT inhibited ATP-induced calcium influx, similar to TRPC inhibitor SKF96365. Finally, TDT-mediated protection of podocytes was abolished by protein kinase G inhibitor KT5823. In conclusion, TDT treatment attenuated heart and kidney dysfunction, accompanied by podocyte protection through inhibition of TRPC6. Thus, long-acting NPs could be a new avenue for treatment of heart failure.

New echocardiographic parameters in the diagnosis of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is a serious clinical disease. The pathophysiology of HFpEF is complex, and specific diagnostic criteria have evolved over time. Limited data are available on the quantification of diastolic function using two-dimensional real-time echocardiography, and a simple parameter has not yet been established. The aim of this work is to evaluate new echocardiographic parameters-the diastolic wall strain of the posterior wall (DWS PW) and the vortex formation time (VFT). Echocardiographic data from 111 subjects with exertional dyspnea and normal left ejection fraction (Group A) and 20 healthy volunteers (Group B) were retrospectively evaluated. In addition to the standard parameters used in the diagnosis of HFpEF, DWS PW and VFT were assessed in all patients. HFpEF was diagnosed in 38 patients with dyspnea (Group A1). The remaining 73 patients did not meet the established criteria for a positive diagnosis of HFpEF (Group A2). We discovered that both observed parameters were significantly lower in patients with HFpEF than in other groups. Multivariate analysis revealed that both DWS PW and VFT independently predicted the presence of HFpEF. DWS PW and VFT are simple parameters in the evaluation of diastolic function and may play a potential role as a part of an integrated approach to the assessment of HFpEF.

Increased Left Ventricular Diastolic Stiffness Is Associated With Heart Failure Symptoms in Aortic Stenosis Patients With Preserved Ejection Fraction

BACKGROUND

Clinical risk factors associated with heart failure (HF) symptoms in aortic stenosis (AS) patients with preserved ejection fraction (EF) have not been fully identified. We hypothesized that left ventricular (LV) diastolic stiffness is associated with HF symptoms in patients with AS.

METHODS AND RESULTS

We retrospectively evaluated 275 patients with at least moderate AS (aortic valve area <1.5 cm²) and preserved EF (≥50%). LV diastolic stiffness was evaluated with the use of echocardiographic parameters, diastolic wall strain (DWS, a measure of LV wall stiffness), and K_LV (a marker of LV chamber stiffness). There were 69 patients with HF. Patients with HF were older, were more likely to be African American, had a higher body mass index, and had more hypertension and coronary artery disease (P < .05 for all). Aortic valve area index and mean pressure gradient across the aortic valve were not different between patients with and without HF. Despite similar echocardiographic parameters of AS severity, patients with HF had stiffer LV (DWS 0.21 ± 0.06 vs 0.25 ± 0.06 [P < .01], K_LV 0.17 ± 0.11 vs 0.13 ± 0.08 [P < .01]). Logistic regression analyses revealed that after adjusting for age, race, body mass index, history of hypertension, and coronary artery disease, LV diastolic stiffness parameters remained significantly associated with HF symptoms.

CONCLUSIONS

LV diastolic stiffness is independently associated with HF in AS patients with preserved EF.

Left Ventricular Stiffness in Adolescents and Young Adults with Repaired Tetralogy of Fallot

Left ventricular (LV) remodeling after tetralogy of Fallot (TOF) repair may influence LV stiffness. We hypothesized that LV stiffness is altered after TOF repair and related to myocardial calibrated integrated backscatter (cIB) and LV diastolic myocardial deformation. Seventy-seven TOF patients and 80 controls were studied. LV stiffness was assessed by diastolic wall strain (DWS) as defined by (LVPW_systole-LVPW_diastole)/LVPW_systole, where LVPW is LV posterior wall thickness, and stiffness index as defined by (E/e/LV end-diastolic dimension), where E and e are respectively early diastolic transmitral inflow and mitral annular velocities. Septal and LVPW cIB and LV diastolic strain rates were determined. Patients had significantly lower DWS (p < 0.001), higher stiffness index (p < 0.001), and greater cIB (p < 0.001). LV DWS correlated negatively with LV stiffness index (r = -0.31, p < 0.001), septal cIB (r = -0.21, p = 0.01), E/e ratio (r = -0.30, p < 0.001) and RV end-diastolic area (r = -0.31, p < 0.001), and positively with LV early (r = 0.33, p < 0.001) and late (r = 0.20, p = 0.01) diastolic strain rates and RV fractional area change (FAC) (r = 0.24, p = 0.003). Multivariate analysis revealed E/e (β = -0.26, p = 0.008), RV end-diastolic area (β = -0.20, p = 0.02), and RV FAC (β = 0.18, p = 0.01) as significant correlates of DWS. Left ventricular stiffening occurs after TOF repair and is related to impaired LV diastolic myocardial deformation, myocardial cIB, and RV volume overload.

Prognostic Impact of Diastolic Wall Strain in Patients at Risk for Heart Failure

Diastolic wall strain (DWS) is based on the linear elastic theory, according to which decreased wall thinning during diastole reflects reduced left ventricular compliance and thus increased diastolic stiffness. Increased diastolic stiffness as assessed by DWS is associated with a worse prognosis in patients who have heart failure (HF) with preserved ejection fraction. However, there are no data about the prognostic value of DWS derived by M-mode echocardiography in patients at risk for HF. We retrospectively enrolled 1829 consecutive patients without prior HF who were hospitalized for cardiovascular (CV) diseases in our hospital between 2005 and 2012. Patients were divided into two groups stratified by DWS (median value 0.34). The study endpoint was the composite of major adverse cardiovascular events (MACE), including all-cause death, myocardial infarction, stroke, and hospitalization for HF. Over a 4.2-year median follow-up, adverse events were observed in 322 patients (17.6%). In Kaplan-Meier analysis, patients with low DWS (≤ 0.34, n = 915) showed worse prognoses than those with high DWS (> 0.34, n = 914) (MACE incidence 39.4% versus 31.9%, P = 0.011). In multivariate Cox proportional hazards analysis after the adjustment for age, sex, and echocardiographic parameters, low DWS (≤ 0.34) was significantly associated with the incidence of MACE (hazard ratio: 1.26, 95% confidence interval: 1.01-1.59; P = 0 .045). In patients without prior HF, DWS is an independent predictor of MACE. Simple assessment of DWS might improve risk stratification for CV events in those patients.

Left ventricular stiffness estimated by diastolic wall strain is associated with paroxysmal atrial fibrillation in structurally normal hearts

BACKGROUND

Left ventricular (LV) diastolic dysfunction depends on an impaired relaxation and stiffness. Abnormal LV relaxation contributes to the development of atrial fibrillation (AF), but the role of LV stiffness in AF remains unclear.

HYPOTHESIS

Diastolic wall strain (DWS), a load-independent, noninvasive direct measure of LV stiffness, correlates with prevalent AF.

METHODS

This study included 328 consecutive subjects with structurally normal hearts: 164 paroxysmal AF patients and 164 age- and sex-matched (1:1) controls. We calculated the DWS from the M-mode echocardiographic measurements of the LV posterior wall thickness at end-systole and end-diastole during sinus rhythm.

RESULTS

The DWS was lower in the AF patients (0.35 ± 0.07) than in the controls (0.41 ± 0.06; P < 0.001). After adjusting for the risk factors of AF using a conditional logistic regression analysis, a history of hypertension, plasma brain-type natriuretic peptide level, and DWS were independently associated with AF prevalence, whereas body mass index, LV mass index, left atrial volume, and any conventional indices of the diastolic function were not. A low DWS (<0.380) was the strongest indicator of AF (odds ratio: 6.22, 95% confidence interval: 3.08-14.2, P < 0.001).

CONCLUSIONS

Increased LV stiffness estimated by DWS was a strong determinant of the prevalence of AF. LV stiffness may play a role in the pathogenesis of paroxysmal AF in structurally normal hearts.

Ventricular-Arterial Function and Coupling in the Adult Fontan Circulation

Background

In adult Fontan patients, ventricular or arterial dysfunction may impact homeostasis of the Fontan circulation and predispose to heart failure. We sought to characterize ventricular‐arterial (VA) properties in adult Fontan patients.

Methods and Results

Adult Fontan patients (n=170), including those with right (SRV, n=57) and left (SLV, n=113) dominant ventricular morphology, were compared to age, sex, and body size matched controls (n=170). Arterial function, load‐insensitive measures of contractility, VA coupling, diastolic function, and ventricular efficiency were assessed. Compared to controls, Fontan patients had similar arterial (Ea), but lower end‐systolic ventricular (Ees), elastance, preload recruitable stroke work and peak power index, impaired VA coupling, eccentric remodeling, reduced ventricular efficiency and increased diastolic stiffness (P<0.05 for all). Ventricular efficiency declined steeply with higher heart rate in Fontan, but not control, patients. Among Fontan patients (n=123) and controls (n=162) with preserved cardiac index (CI; ≥2.5 L/min per m²), Fontan patients had worse contractility than controls, but CI was preserved owing to relative tachycardia, lower afterload, and eccentric remodeling. However, 25% of Fontan patients had reduced CI and were distinguished from those with preserved CI by less‐eccentric remodeling and worse diastolic function, rather than more‐impaired contractility.

Conclusions

Adult Fontan patients have contractile and diastolic dysfunction with normal afterload, impaired VA coupling, and reduced ventricular efficiency with heightened sensitivity to heart rate. Maintenance of CI is dependent on lower afterload, eccentric remodeling, and relative preservation of diastolic function. These data contribute to our understanding of circulatory physiology in adult Fontan patients.

Prognostic value of diastolic wall strain in patients with chronic heart failure with reduced ejection fraction

Left ventricular (LV) diastolic dysfunction plays a crucial role in heart failure with reduced ejection fraction (HFrEF). LV stiffness is a main component of diastolic function, but its role and prognostic value in HFrEF patients remains unclear. This study aimed to determine whether diastolic wall strain (DWS) as a noninvasive and simple marker of LV stiffness can predict the prognosis of HFrEF patients who were administrated chronic beta blockade enough. We enrolled 75 HFrEF patients who were administrated chronic beta blockade. We evaluated the echocardiographic parameters and plasma brain natriuretic peptide (BNP) before the induction of beta blockade and also obtained pulmonary artery wedge pressure (PAWP) from the right heart catheterization. DWS was obtained from standard M-mode echocardiography as follows: DWS = [(LV posterior wall thickness (LVPWT) at end-systole - LVPWT at end-diastole)/LVPWT] at end-systole. DWS did not correlate with other echocardiographic parameters and PAWP. We defined primary outcome as HF hospitalization or cardiovascular death and followed for 7 years. The incidence rate was higher in low DWS than high DWS patients (p = 0.04). Other echocardiographic parameters could not be significant predictors of HFrEF outcome under the condition of enough beta blocker therapy. In multivariate analysis, DWS was the independent contributor to the event-free time. Impaired LV stiffness evaluated with DWS was associated with worse outcome and DWS might be an independent prognostic factor in HFrEF patients with chronic beta blockade.

Increasing aminoterminal-pro-B-type natriuretic peptide precedes the development of arterial hypertension: the multiethnic study of atherosclerosis

BACKGROUND

Longitudinal associations between the aminoterminal pro-B-type natriuretic peptide (NT-proBNP) and incident hypertension are lacking.

METHODS

We tested associations between baseline NT-proBNP (bNT-proBNP) and change in NT-proBNP (ΔNT-proBNP) (visit 3 NT-proBNP - bNT-proBNP, 3.2 years apart) with incident hypertension (SBP ≥ 140 and/or DBP ≥90 mmHg or taking antihypertensive medications). Incident hypertension was evaluated in 5596 individuals in the Multi-Ethnic Study of Atherosclerosis without hypertension at baseline (53% women, age range 45-84 years without overt cardiovascular disease) and follow-up for 9.5 years and in a subgroup (1550) who had bNT-proBNP less than 100 pg/ml and no hypertension at visit 3. Incident hypertension was regressed (proportional hazards) on quintiles of bNT-proBNP (range) (reference <19.2, 19.3-40.8, 40.9-70.9, 71-135.2, and >135.5) and also on ΔNT-proBNP categories (reference <-10, -10 to 10, >10 to 50, and >50 pg/ml). Hazard ratios were adjusted for age, race, sex, education, diabetes, obesity, left ventricle mass/height, SBP and DBP, interleukin-6, salt intake, estimated glomerular filtration rate, and exercise.

RESULTS

Compared with the reference category, hazard ratios (95% confidence interval) for incident hypertension compared with the first quintile of bNT-proBNP were 1.47 (1.13-1.93), 1.57 (1.18-2.09), 1.52 (1.12-2.06), and 2.36 (1.62-3.41). Hazard ratios for incident hypertension by categories of ΔNT-proBNP from 3.2 to 9.5 years follow-up were 0.98 (0.62-1.56), 1.13 (0.72-1.79), and 1.82 (1.07-3.12).

CONCLUSION

The development of hypertension tended to be preceded by elevated levels of bNT-proBNP or a substantial positive ΔNT-proBNP.

The evaluation of diastolic function using the diastolic wall strain (DWS) before and after radical surgery for congenital diaphragmatic hernia

OBJECTIVE

The measurement of diastolic wall strain (DWS), a new method of evaluating cardiac diastolic function, was employed to evaluate ventricular diastolic function in patients with congenital diaphragmatic hernia (CDH).

MATERIALS AND METHODS

Eighteen neonates with a CDH who were born and treated in our hospital between September 2009 and January 2013 were studied. The left ventricular posterior wall thickness during the systolic phase (PWs) and diastolic (PWd) phase was measured using M-mode imaging, and the DWS was calculated as (PWs-PWd)/PWs. The Tei index, the isovolumic relaxation time (IRT), and the fraction shortening (FS) were measured as indices of cardiac function in 14, 15, and 18 cases, respectively. Cardiac function was measured before and after surgery. Statistical analyses were performed using the paired t test.

RESULTS

The pre- and postoperative DWS, Tei index, IRT and FS values were 0.19 ± 0.06 and 0.26 ± 0.11 (P < 0.01), 0.40 ± 0.12 and 0.31 ± 0.11 (P < 0.05), 48 ± 14 and 39 ± 5.0 ms (P < 0.05), 30 ± 7.7 and 34 ± 7.4 % (P < 0.05), respectively.

CONCLUSION

The diastolic and systolic functions were not only measured by the Tei index, IRT and FS values, but also by the DWS value, which improved after surgery. The measurement of DWS is an easy and useful method for evaluating the diastolic function of CDH patients.

Clinical relevance of right ventricular diastolic stiffness in pulmonary hypertension

Right ventricular (RV) diastolic stiffness is increased in pulmonary arterial hypertension (PAH) patients. We investigated whether RV diastolic stiffness is associated with clinical progression and assessed the contribution of RV wall thickness to RV systolic and diastolic stiffness.

Using single-beat pressure–volume analyses, we determined RV end-systolic elastance (Ees), arterial elastance (Ea), RV­–arterial coupling (Ees/Ea), and RV end-diastolic elastance (stiffness, Eed) in controls (n=15), baseline PAH patients (n=63) and treated PAH patients (survival >5 years n=22 and survival <5 years n=23).

We observed an association between Eed and clinical progression, with baseline Eed >0.53 mmHg·mL-1 associated with worse prognosis (age-corrected hazard ratio 0.27, p=0.02). In treated patients, Eed was higher in patients with survival <5 years than in patients with survival >5 years (0.91±0.50 versus 0.53±0.33 mmHg·mL-1, p<0.01). Wall-thickness-corrected Eed values in PAH patients with survival >5 years were not different from control values (0.76±0.47 versus 0.60±0.41 mmHg·mL-1, respectively, not significant), whereas in patients with survival <5 years, values were significantly higher (1.52±0.91 mmHg·mL-1, p<0.05 versus controls).

RV diastolic stiffness is related to clinical progression in both baseline and treated PAH patients. RV diastolic stiffness is explained by the increased wall thickness in patients with >5 years survival, but not in those surviving <5 years. This suggests that intrinsic myocardial changes play a distinctive role in explaining RV diastolic stiffness at different stages of PAH.

Decreased diastolic wall strain is associated with adverse left ventricular remodeling even in patients with normal left ventricular diastolic function

Background

The pathophysiology of diastolic dysfunction is complex, but can be simply described as impaired LV myocardial relaxation and/or increased LV stiffness. The objective of this study is to clarify true normal left ventricular (LV) diastolic function and early stage of diastolic dysfunction before relaxation abnormality develops in patients with normal LV diastolic function using simple diastolic wall strain (DWS) in South Korea.

Methods

DWS which is a non-invasive, load-independent, and reproducible estimator of LV stiffness using two-dimensional echocardiography using the difference between posterior wall thickness in systole and diastole to approximate LV stiffness. A total of 349 consecutive patients with normal LV diastolic function by echocardiography were enrolled. According to DWS, patients were divided into two groups: high DWS (≥median 175) vs. low DWS (<median 174).

Results

Patients with low DWS were more obese and showed higher blood pressure, and had more prevalent hypertension and hyperlipidemia. In addition, those with low DWS had higher LV end-systolic volume, LV mass index, E/E’ and lower ejection fraction and E’ velocity. Among them, higher LVESV and LVMI were independently associated with low DWS.

Conclusions

These data suggests that simple DWS might be helpful in identifying a subgroup of subtle diastolic dysfunction. Our data suggest that early change of diastolic dysfunction might start with abnormal LV geographic changes preceding functional changes.

Diastolic wall strain: a simple marker of abnormal cardiac mechanics

BACKGROUND

Diastolic wall strain (DWS), defined using posterior wall thickness (PWT) measurements from standard echocardiographic images (DWS = [PWT(systole)-PWT(diastole)]/PWT(systole)), has been proposed as a marker of left ventricular (LV) diastolic stiffness. However, the equation for DWS is closely related to systolic radial strain, and whether DWS is associated with abnormal cardiac mechanics (reduced systolic strains and diastolic tissue velocities) is unknown. We sought to determine the relationship between DWS and systolic and diastolic cardiac mechanics.

METHODS

We calculated DWS and performed speckle-tracking analysis in a large population- and family-based study (Hypertension Genetic Epidemiology Network [HyperGEN]; N=1907 after excluding patients with ejection fraction [EF] <50% or posterior wall motion abnormalities). We measured global longitudinal, circumferential, and radial strain (GLS, GCS, and GRS, respectively) and early diastolic (e') tissue velocities, and we determined the independent association of DWS with cardiac mechanics using linear mixed effects models to account for relatedness among study participants. We also prospectively performed receiver-operating characteristic (ROC) analysis of DWS for the detection of abnormal cardiac mechanics in a separate, prospective validation study (N=35).

RESULTS

In HyperGEN (age 51 ± 14 years, 59% female, 45% African-American, 57% hypertensive), mean DWS was 0.38 ± 0.05. DWS decreased with increasing comorbidity burden (β-coefficient -0.013 [95% CI -0.015, -0.011]; P<0.0001). DWS was independently associated with GLS, GCS, GRS, and e' velocity (adjusted P<0.05) but not LV chamber compliance (EDV20, P=0.97). On prospective speckle-tracking analysis, DWS correlated well with GLS, GCS, and GRS (R=0.61, 0.57, and 0.73, respectively; P<0.001 for all comparisons). C-statistics for DWS as a diagnostic test for abnormal GLS, GCS, and GRS were: 0.78, 0.79, and 0.84, respectively.

CONCLUSIONS

DWS, a simple parameter than can be calculated from routine 2D echocardiography, is closely associated with systolic strain parameters and early diastolic (e') tissue velocities but not LV chamber compliance.

Developmental changes in the left ventricular diastolic wall strain on M-mode echocardiography

BACKGROUND

The diastolic wall strain (DWS) of the left ventricle has been proposed as an indicator of left ventricular (LV) wall stiffness. The DWS is calculated as follows using M-mode echocardiography:[Formula: see text]Although this index is simple and clinically useful, normal values for children, including neonates, have not been reported.

METHODS

The DWS was measured in 235 healthy people, ranging from neonates to adults. They were classified into 8 subgroups according to their age. The DWS was compared with conventional echocardiographic parameters for left ventricle function, including shortening fraction of the left ventricle, the Tei index, E/A of mitral flow, mitral annular tissue Doppler velocity during systole (s') and during early diastole (e'), and the E/e' ratio.

RESULTS

The DWS in the just after birth group was 0.28 ± 0.11, which was significantly lower than that of the remaining groups (p < 0.05), except for the neonate group at 5-10 days after birth. The DWS was highest in the 1-9 years of age group, and then gradually decreased with age. Stepwise regression of various echocardiographic parameters showed that e' was the most relevant parameter for the DWS (β = 0.64).

CONCLUSIONS

Normal values for the DWS of the left ventricle change with age. The data reported in this study can be used as normal values for the DWS of the left ventricle determined by M-mode echocardiography.

Low diastolic wall strain is associated with raised post-exercise E/E' ratio in elderly patients without obvious myocardial ischemia

BACKGROUND

It has been reported that the diastolic wall strain (DWS) inversely correlates with the myocardial stiffness constant. The ratio of early diastolic transmitral flow velocity to annulus velocity (E/E') correlates with the left ventricular (LV) filling pressure. Increased LV wall stiffness is thought be associated with increased LV filling pressure after exercise. The purpose of this study was to evaluate the correlation between the DWS and post-exercise E/E' in elderly patients without obvious myocardial ischemia.

METHODS

Fifty-eight elderly patients (age = 74 ± 6 years) who underwent treadmill stress echocardiography were studied. All patients had normal LV wall motion at rest, and patients with exercise-induced wall motion abnormality were excluded. The DWS was calculated as follows: DWS = (PWTs - PWTd)/PWTs, where PWTs is the LV posterior wall thickness at end-systole and PWTd is that at end-diastole. As previously reported, DWS ≤ 0.33 was defined as low DWS and E/E' ≥15.0 was defined as a marker of increased LV filling pressure.

RESULTS

Eighteen patients had low DWS. Patients with low DWS had greater post-exercise E/E' (17.9 ± 3.2 vs. 12.8 ± 3.3, p < 0.0001). The DWS was inversely and strongly correlated with post-exercise E/E' (r (2) = 0.534, p < 0.0001). Low DWS predicted the development of raised post-exercise E/E' ≥15.0 with a positive predictive value of 94 % and a negative predictive value of 85 %.

CONCLUSION

In elderly patients without obvious myocardial ischemia, the DWS correlates strongly and inversely with post-exercise E/E'. Patients with low DWS were likely to develop raised E/E' after exercise.

Interleukin-16 promotes cardiac fibrosis and myocardial stiffening in heart failure with preserved ejection fraction

BACKGROUND

Chronic heart failure (CHF) with preserved left ventricular (LV) ejection fraction (HFpEF) is observed in half of all patients with CHF and carries the same poor prognosis as CHF with reduced LV ejection fraction (HFrEF). In contrast to HFrEF, there is no established therapy for HFpEF. Chronic inflammation contributes to cardiac fibrosis, a crucial factor in HFpEF; however, inflammatory mechanisms and mediators involved in the development of HFpEF remain unclear. Therefore, we sought to identify novel inflammatory mediators involved in this process.

METHODS AND RESULTS

An analysis by multiplex-bead array assay revealed that serum interleukin-16 (IL-16) levels were specifically elevated in patients with HFpEF compared with HFrEF and controls. This was confirmed by enzyme-linked immunosorbent assay in HFpEF patients and controls, and serum IL-16 levels showed a significant association with indices of LV diastolic dysfunction. Serum IL-16 levels were also elevated in a rat model of HFpEF and positively correlated with LV end-diastolic pressure, lung weight and LV myocardial stiffness constant. The cardiac expression of IL-16 was upregulated in the HFpEF rat model. Enhanced cardiac expression of IL-16 in transgenic mice induced cardiac fibrosis and LV myocardial stiffening accompanied by increased macrophage infiltration. Treatment with anti-IL-16 neutralizing antibody ameliorated cardiac fibrosis in the mouse model of angiotensin II-induced hypertension.

CONCLUSION

Our data indicate that IL-16 is a mediator of LV myocardial fibrosis and stiffening in HFpEF, and that the blockade of IL-16 could be a possible therapeutic option for HFpEF.

Balloon type elasticity sensing for left ventricle of small laboratory animal

This paper describes an elasticity sensing system for left ventricle of small laboratory animal. We first show the basic concept of the proposed method, where a ring shaped specimen is dilated by a balloon type probe using a pressure based control, and the elasticity of the specimen is estimated by using the stress and strain information. We introduce a dual cylinder model for approximating the strengths of the specimen's material and the balloon. Based on this model, we can derive Young's modulus of the specimen. After explaining the developed experimental system, we show a couple of experimental results using rats and mice, where HFPEF (Heart Failure Preserved Ejection Fraction) group can be distinguished from a normal group.

Diastolic stiffness as assessed by diastolic wall strain is associated with adverse remodelling and poor outcomes in heart failure with preserved ejection fraction

AIMS

The pathophysiology of heart failure with preserved ejection fraction (HFpEF) is complex but increased left ventricular (LV) diastolic stiffness plays a key role. A load-independent, non-invasive, direct measure of diastolic stiffness is lacking. The diastolic wall strain (DWS) index is based on the linear elastic theory, which predicts that impaired diastolic wall thinning reflects resistance to deformation in diastole and thus, increased diastolic myocardial stiffness. The objectives of this community-based study were to determine the distribution of this novel index in consecutive HFpEF patients and healthy controls, define the relationship between DWS and cardiac structure and function and determine whether increased diastolic stiffness as assessed by DWS is predictive of the outcome in HFpEF.

METHODS AND RESULTS

Consecutive HFpEF patients (n = 327, EF ≥ 50%) and controls (n = 528) from the same community were studied. Diastolic wall strain was lower in HFpEF (0.33 ± 0.08) than in controls (0.40 ± 0.07, P < 0.001). Within HFpEF, those with DWS ≤ median (0.33) had higher LV mass index, relative wall thickness, E/e', Doppler-estimated LV end-diastolic pressure to LV end-diastolic volume ratio, left atrial volume index, and brain natriuretic peptide (BNP) levels than those with DWS > median. Heart failure with preserved ejection fraction patients with DWS ≤ median had higher rate of death or HF hospitalization than those with DWS > median (P = 0.003) even after the adjustment for age, gender, log BNP, LV geometry, or log E/e' (P < 0.01).

CONCLUSION

These data suggest that DWS, a simple index, is useful in assessing diastolic stiffness and that more advanced diastolic stiffness is associated with worse outcomes in HFpEF.

Diabetic retinopathy is associated with impaired left ventricular relaxation

BACKGROUND

Diabetic retinopathy (DR) is an independent predictor of heart failure (HF) in patients with diabetes mellitus (DM). However, it is unclear how DR is related to the development of HF. We hypothesized that DR is associated with left ventricular (LV) diastolic dysfunction, which is well recognized to subsequently result in HF.

METHODS AND RESULTS

Data were collected in 63 consecutive patients with DM and LV ejection fraction (EF) ≥50%. Patients were excluded if they had HF diagnosed according to the modified Framingham criteria. Doppler echocardiographic indices including peak early-diastolic mitral annular movement velocity (E') were obtained in each patient.We also assessed the diastolic index of echocardiographic color kinesis (CK-DI), which proportionally decreases with LV relaxation abnormality independently of LV filling pressure, as recently published. The DM patients were divided into groups without (DM-N; n = 30) and with (DM-DR; n = 33) DR. Age, gender, LV end-diastolic dimension, EF, E/A ratio of the transmitral flow velocity curves, E', and E/E' were not different between DM-N and DM-DR. However, CK-DI was significantly lower in DM-DR than DM-N.

CONCLUSIONS

DR is associated with LV diastolic dysfunction, and this may at least in part explain the increased incidence of HF in DM patients with DR.

Competing risks of heart failure with preserved ejection fraction in diabetic patients

AIMS

The prevalence of heart failure with preserved ejection fraction (HFpEF) has increased in the past two decades, and diabetes mellitus (DM) is frequently associated with HFpEF. Although it has been demonstrated that left ventricular (LV) diastolic and vascular functional abnormalities are generally observed in HFpEF, it remains to be clinically elucidated how an asymptomatic stage progresses to symptomatic HFpEF in DM patients. We aimed to identify risk factors associated with incident HFpEF in DM patients and to evaluate the contribution of LV relaxation and compliance to the development of HFpEF.

METHODS AND RESULTS

The study included 544 consecutive Japanese DM patients with ejection fraction ≥50%. Patients with coronary artery disease or serum creatinine ≥2.0 mg/dL were excluded. Multiple logistic regression analysis revealed that obesity, female gender, anaemia, and impaired LV compliance were independently associated with the prevalence of HFpEF, and that age, LV mass index, an index of LV relaxation, estimated glomerular filtration rate, and history of hypertension were not. There was no difference in haemoglobin A1c or brachial-ankle pulse wave velocity between the DM patients with and without HFpEF.

CONCLUSIONS

This study suggests that exacerbation of LV compliance impairment, rather than of relaxation abnormality or vascular stiffening, plays a crucial role in the induction of HFpEF in DM patients regardless of the severity of DM and renal dysfunction. Anaemia and obesity may also contribute to the transition from asymptomatic stage to symptomatic HFpEF even without further progression of LV diastolic dysfunction.

Transition from asymptomatic diastolic dysfunction to heart failure with preserved ejection fraction: roles of systolic function and ventricular distensibility

BACKGROUND

Systolic abnormality, as well as diastolic dysfunction, is observed in patients with heart failure with preserved ejection fraction (HFPEF). However, the role of these 2 conditions in the transition from asymptomatic diastolic dysfunction to symptomatic heart failure remains unclear. We recently demonstrated that diastolic wall strain (DWS) inversely correlates to the myocardial stiffness constant.

METHODS AND RESULTS

This study consisted of 127 subjects: 52 consecutive HFPEF patients (HFPEF group), 50 asymptomatic hypertensive patients with ejection fraction ≥50% whose age, gender and left ventricular (LV) mass index matched those of the HFPEF group (HT group) and 25 normal volunteers (Normal group). The tissue Doppler-derived peak systolic and early diastolic velocities of the mitral annulus were significantly decreased in groups HFPEF and HT than in group Normal, but were not significantly different between groups HFPEF and HT. DWS was significantly lower in group HFPEF than in group HT.

CONCLUSIONS

The transition from asymptomatic diastolic dysfunction stage to HFPEF stage is not attributed to progression of systolic abnormality, and exacerbation of LV distensibility rather than relaxation plays a crucial role in the development of HFPEF.