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

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.

Lifetime evaluation of left ventricular structure and function in male ApoE null mice after gamma and space-type radiation exposure

The space radiation (IR) environment contains high charge and energy (HZE) nuclei emitted from galactic cosmic rays with the ability to overcome current shielding strategies, posing increased IR-induced cardiovascular disease risks for astronauts on prolonged space missions. Little is known about the effect of 5-ion simplified galactic cosmic ray simulation (simGCRsim) exposure on left ventricular (LV) function. Three-month-old, age-matched male Apolipoprotein E (ApoE) null mice were irradiated with 137Cs gamma (γ; 100, 200, and 400 cGy) and simGCRsim (50, 100, 150 cGy all at 500 MeV/nucleon (n)). LV function was assessed using transthoracic echocardiography at early/acute (14 and 28 days) and late/degenerative (365, 440, and 660 days) times post-irradiation. As early as 14 and 28-days post IR, LV systolic function was reduced in both IR groups across all doses. At 14 days post-IR, 150 cGy simGCRsim-IR mice had decreased diastolic wall strain (DWS), suggesting increased myocardial stiffness. This was also observed later in 100 cGy γ-IR mice at 28 days. At later stages, a significant decrease in LV systolic function was observed in the 400 cGy γ-IR mice. Otherwise, there was no difference in the LV systolic function or structure at the remaining time points across the IR groups. We evaluated the expression of genes involved in hemodynamic stress, cardiac remodeling, inflammation, and calcium handling in LVs harvested 28 days post-IR. At 28 days post-IR, there is increased expression of Bnp and Ncx in both IR groups at the lowest doses, suggesting impaired function contributes to hemodynamic stress and altered calcium handling. The expression of Gals3 and β-Mhc were increased in simGCRsim and γ-IR mice respectively, suggesting there may be IR-specific cardiac remodeling. IR groups were modeled to calculate the Relative Biological Effectiveness (RBE) and Radiation Effects Ratio (RER). No lower threshold was determined using the observed dose-response curves. These findings do not exclude the possibility of the existence of a lower IR threshold or the presence of IR-induced cardiovascular disease (CVD) when combined with additional space travel stressors, e.g., microgravity.

Novel left and right ventricular strain analysis to detect subclinical myocardial dysfunction in cardiac allograft rejection

Early detection of acute cellular rejection (ACR) by echocardiography shows potential clinical benefit as ACR remains a significant contributor to morbidity and mortality. This retrospective, longitudinal study sought to investigate the use of novel left (LV) and right ventricular (RV) strain analysis to detect biopsy proven ACR. 46 heart transplant patients (Mean age 46 ± 16 years) with biopsy proven ACR were grouped according to biopsy results: 1R-ACR (n = 36) and 2R-ACR (n = 10). Serial two-dimensional transthoracic echocardiography with strain analysis was performed. Echocardiographic parameters were serially measured: (1) rejection free period (0R-ACR); (2) pre-ACR period (pre-ACR); (3) during ACR (1R-ACR or 2R-ACR) and (4) post-ACR (Post-ACR). Significant reductions for LV Global Longitudinal Strain (LV GLS) and LV Early diastolic Strain rate (LV ESr) were observed between 0R-ACR and pre-ACR (LV GLS 0R-ACR: 17.3% vs Pre-2R ACR: 15.4%, p = 0.016; LV ESr 0R-ACR: 1.00/s vs Pre-2R ACR: 0.74/s, p = 0.007) with LV ESr demonstrating the highest sensitivity (92%) and specificity (81%) to predict ACR. LV ESr and the E/LV ESr ratio were significantly different (p = 0.0001; p = 0.016) during pre-1R ACR period vs 0R whereas LV GLS showed no significant differences for grade 1R-ACR. Diastolic mechanical dispersion showed significant increases in dispersion during ACR for the 1R-ACR group and early significant increases pre-2R ACR. Systolic and diastolic RV strain parameters showed a similar trend for both ACR groups. Systolic and diastolic strain parameters can detect myocardial dysfunction before biopsy confirmed 2R-ACR. Early diastolic strain rate parameters are most sensitive detecting subclinical myocardial dysfunction pre-ACR. Novel strain parameters are potentially useful clinical tool for prediction of early ACR in heart transplant.

Cardiotoxicidad por antraciclinas en supervivientes de cáncer durante la infancia

Introducción: a nivel mundial, cada año cerca de 300.000 niños entre 0 y 19 años son diagnosticados con cáncer. El porcentaje de supervivientes va en aumento, llegando a 80 % en países desarrollados y 60 % en América Latina. Sin embargo, la expectativa y la calidad de vida de estas personas pueden verse comprometidas ante el desarrollo de cardiotoxicidad, un efecto adverso asociado al uso de algunos agentes antineoplásicos, como los antracíclicos.Objetivo: resaltar los aspectos clínicos relevantes para la prevención, detección oportuna, tratamiento y seguimiento de la cardiotoxicidad secundaria a la administración de antraciclinas durante la infancia.Síntesis de contenido: reflexión teórica que presenta consideraciones clínicas relevantes para guiar las acciones de enfermería y del equipo multidisciplinario en la atención y el cuidado de la salud cardiovascular de los supervivientes de cáncer a cualquier edad. Es importante destacar que en población pediátrica la única estrategia efectiva de prevención primaria para cardiotoxicidad por antraciclinas es la administración de dexrazoxano, mientras que la prevención secundaria debe incluir detección oportuna, control y  seguimiento de las alteraciones de la función cardíaca y de los factores de riesgo cardiovascular. Por su parte, la prevención terciaria se centra en el control de la enfermedad y el manejo farmacológico. Conclusiones: no existe un  tratamiento estándar para la cardiotoxicidad inducida por quimioterapia o radioterapia, siendo el objetivo principal de este tipo de tratamientos prevenir o retrasar la remodelación del ventrículo izquierdo. Todos los supervivientes requieren seguimiento vitalicio y búsqueda activa de signos de cardiotoxicidad, siendo fundamental la acción conjunta de diferentes profesionales y la consolidación de los servicios de cardio-oncología.

Diastolic strain imaging: a new non-invasive tool to detect subclinical myocardial dysfunction in early cardiac allograft rejection

Acute cellular rejection (ACR) remains a significant contributor to increased morbidity and mortality in heart transplant recipients. Early detection of ACR by non-invasive imaging is of potential clinical benefit. This study sought to investigate the use of non-invasive early global diastolic strain rate (GDSRe) and global longitudinal strain (GLS) in the detection of biopsy proven ACR. We retrospectively analysed 31 heart transplant patients (Mean age 52 ± 14 years) with biopsy proven ACR who underwent serial transthoracic echocardiographic examination and 2D strain analysis. Traditional echocardiographic systolic and diastolic parameters and novel systolic and diastolic strain imaging were measured during (1) early rejection free period (0R); (2) pre-rejection period (pre-1R); and (3) grade 1R acute cellular rejection (1R-ACR). GDSRe was significantly reduced (p = 0.0001) during the pre-rejection period (pre-1R) (0.74/s) when compared with 0R (0.97/s). GLS was only significantly reduced during 1R-ACR (17.7%), p = 0.001 but could not detect pre-1R (19.9%). Global diastolic strain rate at isovolumic relaxation showed no significant differences between any of the rejection periods. Traditional systolic and diastolic indices showed no significant differences. In conclusion, early global diastolic strain rate is the most sensitive parameter to detect subclinical myocardial dysfunction during early periods of pre-1R prior to biopsy confirmed 1R-ACR. GDSRe is a potential new tool for non-invasive screening of early post-transplant cardiac allograft rejection.

Clinical ascertainment of health outcomes in Asian survivors of childhood cancer: a systematic review

PURPOSE

Survivorship in children with cancer comes at a cost of developing chronic treatment-related complications. Yet, it is still an under-researched area in Asia, which shares the largest proportion of the global childhood cancer burden given its vast population. This systematic review summarizes existing literature on clinically ascertained health outcomes in Asian survivors of childhood cancer.

METHODS

A search was conducted on Ovid Medline and EMBASE for studies that focused on survivors of childhood cancer from countries in East and Southeast Asia; adopted post-treatment clinical ascertainment of organ-specific toxicities or/and secondary malignancy. Studies were excluded if health outcomes were assessed during the acute treatment.

RESULTS

Fifty-nine studies, enrolling a total of 13,442 subjects, were conducted on survivors of leukemia (34%), CNS tumor (14%), and cohorts of survivors with heterogeneous cancer diagnoses (52%). The studies used different medical evaluation methods to assess cardiovascular (15%), metabolic and infertility (32%), and neurological/neurocognitive (20%) outcomes in survivors. The collective findings suggest potential differences in the prevalence of certain late effects (e.g., secondary malignancy and obesity) among Asian and non-Asian populations, which may reflect differences in treatment regimens, practice, genetic variations, or/and socioeconomic disparity.

CONCLUSIONS

We recommend developing collaborative initiatives to build a regional repository of systematically assessed health outcomes and biospecimens to investigate treatment, social-environmental and genetic predictors, and interventions for late effects in this population.

IMPLICATIONS FOR CANCER SURVIVORS

The existing types of chronic health problems identified in this review suggest the need for active screening, better access to survivorship care, and promotion of protective health behavior in Asia.

Resting and exercise arterial dysfunction in anthracycline-treated adult survivors of childhood cancers

BACKGROUND

Emerging evidence suggests potential arterial damage with the use of anthracycline-based chemotherapeutic regimens. We determined arterial function at rest and during exercise in anthracycline-treated adult survivors of childhood cancers.

METHODS

Ninety-six adult survivors (54 males) aged 25.0 ± 5.9 years and 60 (30 males) healthy controls were studied. Central systolic blood pressure (cSBP) and radial augmentation index (rAI) was determined by applanation tonometry. Carotid arterial stiffness and intima-media thickness (IMT) were assessed using high-resolution ultrasound.

RESULTS

At rest, survivors had significantly greater carotid IMT (p < 0.001) and stiffness index (p < 0.001), and higher cSBP (p = 0.037), rAI (p = 0.004) and rAI adjusted for a heart rate of 75/min (p = 0.009) than controls. At submaximal supine exercise testing, survivors had significantly greater percentage increase in carotid stiffness than controls (p < 0.001). Among survivors, 32 and 53% had respectively carotid IMT and exercise stiffness index exceeding normal (> + 2SD of controls). The slopes of increase in carotid IMT (p < 0.001) and exercise-induced changes in carotid stiffness (p < 0.001) with age were significantly greater in survivors than controls. Multivariate analysis revealed carotid IMT (β = 0.32, p < 0.001) to be an significant correlate of dynamic percentage increase in stiffness index during exercise.

CONCLUSIONS

Arterial dysfunction is evident at rest and worsens during exercise in anthracycline-treated adult survivors of childhood cancers.

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.

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.

Assessment of biventricular systolic strain derived from the two-dimensional and three-dimensional speckle tracking echocardiography in lymphoma patients after anthracycline therapy

The aim of this study was to investigate the usefulness of three-dimensional (3D) speckle tracking echocardiography (STE) for assessment of both left and right ventricular systolic function in patients with lymphoma after anthracycline chemotherapy, compared with two-dimensional (2D) STE. Totally eighty-nine patients undergoing anthracycline containing chemotherapy were studied. Echocardiographic assessment included 2D and 3D left ventricular (LV) global longitudinal strain (GLS), global circumferential strain (GCS) and right ventricular (RV) GLS. All the parameters were analyzed at baseline, after the completion of four cycles and at the end of the regimen respectively. The area under the receiver operating characteristic curve was calculated to determine the capability of various echocardiographic parameters to discriminate between before and after chemotherapy. Compared with those at baseline, the 3D GLS and GCS of LV and GLS of RV decreased significantly after four cycles of the therapy (all p < 0.01). At the end of the treatment, 2D GLS and GCS of LV deteriorated markedly (both p < 0.05). The area under the curve for GLS, GCS of LV and GLS of RV derived by 3D were 0.81, 0.66 and 0.78, respectively. The cutoff value with -20.4% of LV GLS by 3D had sensitivity of 81% and specificity of 66% for differentiating patients after therapy from baselines. The cutoff value with -21.9% of RV GLS by 3D had sensitivity of 71% and specificity of 74% fordifferentiating patients after therapy from baselines. The data from this study demonstrated that both 2D and 3D STE can be conducted to evaluate the slight myocardial damage for lymphoma patients after anthracycline chemotherapy. 3D STE could examine subclinical biventricular dysfunction in earlier point than 2D STE.