Role of Right Ventricular Global Longitudinal Strain in Predicting Early and Long-Term Mortality in Cardiac Resynchronization Therapy Patients

Prognostic Value of Strain by Speckle Tracking Echocardiography in Patients with Arrhythmogenic Right Ventricular Cardiomyopathy

Background Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare genetic disorder associated with an elevated risk of life-threatening arrhythmias and progressive ventricular impairment. Risk stratification is essential to prevent major adverse cardiac events (MACE). Our study aimed to investigate the incremental value of strain measured by two-dimensional speckle-tracking echocardiography in predicting MACE in ARVC patients compared to conventional echocardiographic parameters. Methods and Results This was a retrospective, single-centre cohort study of 83 patients with ARVC (51% males, median age 37 years (IQR: 23, 53)) under the care of the Inherited Cardiac Conditions clinic at University Hospital Birmingham. MACE was defined as one of the following: sustained ventricular tachycardia (Sus VT), ventricular fibrillation (VF), appropriate implantable cardio-defibrillator (ICD) therapy [shock/anti-tachycardia pacing (ATP)], heart failure (defined as decompensated heart failure, cardiac index by heart catheter, HF medication, and symptoms), cardiac transplantation, or cardiac death. Echocardiography images were analysed by a single observer for right ventricle (RV) and left ventricular (LV) global longitudinal strain (GLS). Multivariable Cox regression was performed in combination with RV fractional area change and tricuspid annular plane systolic excursion. During three years of follow-up, 12% of patients suffered a MACE. ARVC patients with MACE had significantly reduced RV GLS (-13 ± 6% vs. -23 ± 6%, p < 0.001) and RV free wall longitudinal strain (-15 ± 5% vs. -25 ± 7%, p < 0.001) compared to those without MACE. Conclusions Right ventricular free wall longitudinal strain (RVFWLS) may be a more sensitive predictor of MACE than conventional echocardiographic parameters of RV function. Moreover, RV-free wall longitudinal strain may have superior predictive value compared to RV GLS.

Myocardial strain analysis by cardiac magnetic resonance associated with arrhythmias in repaired tetralogy of Fallot patients

BACKGROUND

Evaluating myocardial function using cardiac magnetic resonance (CMR) feature tracking provides a comprehensive cardiac assessment, particularly a detailed evaluation for patients with repaired tetralogy of Fallot (rTOF). This study aimed to identify factors associated with arrhythmias in rTOF patients utilizing conventional CMR techniques, including myocardial strain measurements.

METHODS

This single-center, retrospective study included 245 rTOF patients who underwent CMR between 2017 and 2023. Patients were stratified based on the presence or absence of arrhythmias during follow-up. The biventricular strain was assessed using CMR-derived feature tracking. Demographic, clinical, and imaging data were collected, and statistical analyses were performed to identify factors associated with arrhythmic events.

RESULTS

The median age at surgery was 5.6 years (range 1-44 years), with the median age at CMR was 27.5 years (range 15-69 years). Over the follow-up period, 25 patients (10.2%) experienced atrial or ventricular arrhythmias. Univariate analysis revealed significant associations between arrhythmic events and older age at surgery and CMR, lower functional class, larger heart size on chest radiograph, and prolonged QRS duration (QRSd). Additionally, arrhythmias were associated with increased right ventricular (RV) volume, reduced RV and left ventricular (LV) ejection fraction (EF), and impaired strain values. Multivariate binary logistic regression, adjusting for age at surgery, NYHA class, QRSd, and cardiothoracic ratio, identified that a lower RV EF (adjusted odds ratio [aOR] 6.97), RV global radial strain (GRS) (aOR 6.68), RV global circumferential strain (GCS) (aOR 6.36), RV global longitudinal strain (GLS) (aOR 3.14), and LV GRS (aOR 3.02) were all significantly associated with arrhythmias.

CONCLUSION

This study highlights the significant contribution of CMR-derived myocardial strain measurements in predicting arrhythmic events in patients with rTOF. In addition to conventional RV EF, strain metrics-particularly those of the right ventricle- emerged as strong, independent predictors of arrhythmias, offering valuable prognostic information for clinical management in this patient population. These findings underscore the importance of myocardial strain analysis as a complementary tool to conventional imaging in evaluating arrhythmic risk in rTOF patients.

CLINICAL TRIAL NUMBER

Not applicable.

Impact of baseline right ventricular function on the response to cardiac resynchronization therapy - A meta-analysis

Baseline right ventricular (RV) function potentially determines the response to Cardiac Resynchronization Therapy (CRT) but is not included in the current selection criteria. In this meta-analysis, we examined the value of echocardiographic indices of RV function as potential predictors of CRT outcomes in patients with standard indications for CRT. Baseline tricuspid annular plane systolic excursion was consistently higher in CRT responders, and this association appears independent of age, sex, ischemic etiology of heart failure, and baseline left ventricular ejection fraction. This proof-of-concept meta-analysis of observational data may justify a more detailed assessment of RV function as an additional component in the selection process of CRT candidates.

Biventricular Function is Impaired in Right Ventricular Septal Pacing-A Prospective Study Using Myocardial Strain Imaging

BACKGROUND

Left ventricular (LV) dysfunction is known to occur after right ventricular (RV) pacing; the effect on RV function is less well studied. The aim of this study was to assess the impact of RV mid-septal pacing upon RV function using the novel parameters of speckle-tracking derived RV global longitudinal strain (RV GLS) and RV free wall strain (RV FWS), as well as the conventional parameters RV fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), and tricuspid annular systolic velocity (RV S').

METHODS

Thirty-two (32) consecutive patients with normal baseline LV and RV function requiring permanent pacemaker insertion (for high-grade AV block or sinus node dysfunction) were prospectively recruited. Echocardiography was performed prior to implantation, at 1 day, 1 month and 1 year after implantation, with 29 patients completing follow-up.

RESULTS

After 1 year, three patients (10%) with otherwise normal RV parameters developed abnormal RV strain patterns. Compared to 1 day after implantation, at 1 year significant reductions were observed in mean RV GLS (-24.8 to -21.8%) RV S' (15.1 to 12.2 cm/s), TAPSE (24.2 to 21.9 mm), RV GLS (-24.8 to -21.8%), left ventricular ejection fraction (LVEF) (66.0 to 57.9%), LV GLS (-19.9 to 17.0), all p<0.01. There was a non-significant reduction for RV FWS (-29.0 to -26.7%, p=0.06) and there was no change in RV FAC (49.1 to 46.9%, p=0.24).

CONCLUSION

We report abnormalities of RV strain developing 1 year after pacemaker insertion. Measurement of myocardial strain is emerging as an additional method to detect patients at risk of RV dysfunction in those who have undergone pacemaker implantation.

Point-of-care echocardiography of the right heart improves acute heart failure risk stratification for low-risk patients: The REED-AHF prospective study

OBJECTIVES

Validated acute heart failure (AHF) clinical decision instruments (CDI) insufficiently identify low-risk patients meriting consideration of outpatient treatment. While pilot data show that tricuspid annulus plane systolic excursion (TAPSE) is associated with adverse events, no AHF CDI currently incorporates point-of-care echocardiography (POCecho). We evaluated whether TAPSE adds incremental risk stratification value to an existing CDI.

METHODS

Prospectively enrolled patients at two urban-academic EDs had POCechos obtained before or <1 h after first intravenous diuresis, positive pressure ventilation, and/or nitroglycerin. STEMI and cardiogenic shock were excluded. AHF diagnosis was adjudicated by double-blind expert review. TAPSE, with an a priori cutoff of ≥17 mm, was our primary measure. Secondary measures included eight additional right heart and six left heart POCecho parameters. STRATIFY is a validated CDI predicting 30-day death/cardiopulmonary resuscitation, mechanical cardiac support, intubation, new/emergent dialysis, and acute myocardial infarction or coronary revascularization in ED AHF patients. Full (STRATIFY + POCecho variable) and reduced (STRATIFY alone) logistic regression models were fit to calculate adjusted odds ratios (aOR), category-free net reclassification index (NRI_cont ), ΔSensitivity (NRI_events ), and ΔSpecificity (NRI_nonevents ). Random forest assessed variable importance. To benchmark risk prediction to standard of care, ΔSensitivity and ΔSpecificity were evaluated at risk thresholds more conservative/lower than the actual outcome rate in discharged patients.

RESULTS

A total of 84/120 enrolled patients met inclusion and diagnostic adjudication criteria. Nineteen percent experiencing the primary outcome had higher STRATIFY scores compared to those event free (233 vs. 212, p = 0.009). Five right heart (TAPSE, TAPSE/PASP, TAPSE/RVDD, RV-FAC, fwRVLS) and no left heart measures improved prediction (p < 0.05) adjusted for STRATIFY. Right heart measures also had higher variable importance. TAPSE ≥ 17 mm plus STRATIFY improved prediction versus STRATIFY alone (aOR 0.24, 95% confidence interval [CI] 0.06-0.91; NRI_cont  0.71, 95% CI 0.22-1.19), and specificity improved by 6%-32% (p < 0.05) at risk thresholds more conservative than the standard-of-care benchmark without missing any additional events.

CONCLUSIONS

TAPSE increased detection of low-risk AHF patients, after use of a validated CDI, at risk thresholds more conservative than standard of care.

Superior prognostic value of right ventricular free wall compared to global longitudinal strain in patients with repaired tetralogy of Fallot

Objectives

Both right ventricular free wall longitudinal strain (RVFWLS) and right ventricular global longitudinal strain (RVGLS) using two-dimensional speckle tracking echocardiography (2D-STE) has been demonstrated to predict adverse outcomes in patients with repaired tetralogy of Fallot (r-TOF). However, RVGLS may be affected by left ventricular (LV) function owing to the fact that the interventricular septum is also a part of the left ventricle. Therefore, the aim of our study was to compare the predictive value of RVFWLS with that of RVGLS in patients with r-TOF.

Materials and methods

A total of 179 patients with r-TOF were included in this study. RVFWLS, RVGLS, and left ventricle global longitudinal strain (LVGLS) were evaluated by 2D-STE. The adverse clinical events were death or r-TOF-related rehospitalization. Prognostic performance was evaluated by C-statistic and Akaike information criterion (AIC).

Results

Thirty-one patients developed poor outcomes during a median follow-up period of 2.8 years. Compared with patients without end-point events, those with end-point events had higher incidence of moderate/severe pulmonary regurgitation, larger right heart sizes, and lower RV fractional area change (RVFAC), RVFWLS, RVGLS, and LVGLS than those without. Multivariate Cox regression analysis revealed that RVFAC, RVFWLS, RVGLS, and LVGLS were predictive of poor outcomes in patients with r-TOF after adjustment for transannular patch and QRS duration. A Cox model using RVFWLS (C index = 0.876, AIC = 228) was found to predict unfavorable outcomes more accurately than a model with RVGLS (C index = 0.856, AIC = 243), RVFAC (C index = 0.811, AIC = 248), and LVGLS (C index = 0.830, AIC = 248).

Conclusion

Although both RVGLS and RVFWLS are associated with adverse events, RVFWLS provides superior prognostic value than that of RVGLS in patients with r-TOF.

Prognostic Implications of Right Ventricular Free Wall Strain in Recipients of Cardiac Resynchronization Therapy

Right ventricular (RV) function is an important prognostic marker in cardiac resynchronization therapy (CRT) recipients. Measuring RV systolic function with echocardiography, however, remains challenging due to the complexity of right heart morphology. Evaluation of RV function with RV free wall strain (FWS) may improve risk stratification in recipients of CRT compared with conventional RV function parameters. In 871 recipients of CRT (mean age 65 ± 11 years, 75% were men), RV function was assessed by RV fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), and RV FWS measured by speckle tracking echocardiography. RV dysfunction was defined as RV FWS <23%, RV FAC <35%, and TAPSE <17 mm according to present guidelines. Patients were followed up for the primary end point of all-cause mortality. RV FWS identified a higher percentage of patients with RV systolic dysfunction (80.6%) in comparison with RV FAC (44.1%) and TAPSE (60.6%). During a median follow-up of 97 (53 to 145) months, 521 patients (59.8%) died. Recipients of CRT with RV FWS <23% had higher event rates than those with RV FWS ≥23% (p <0.001). On multivariable analysis, RV FWS <23% was independently associated with all-cause mortality (hazard ratio 1.618; 95% confidence interval 1.252 to 2.092; p <0.001) and demonstrated incremental prognostic value over baseline clinical parameters as well as conventional RV function parameters. In conclusion, RV FWS is more sensitive than conventional echocardiographic markers of RV function in detecting impaired RV function. RV FWS is independently associated with all-cause mortality and demonstrates incremental prognostic value over conventional RV function parameters in recipients of CRT.

Accuracy of fully automated right ventricular quantification software with 3D echocardiography: direct comparison with cardiac magnetic resonance and semi-automated quantification software

AIMS

The aim of this study was to determine the accuracy and reproducibility of a novel, fully automated 3D echocardiography (3DE) right ventricular (RV) quantification software compared with cardiac magnetic resonance (CMR) and semi-automated 3DE RV quantification software.

METHODS AND RESULTS

RV volumes and the RV ejection fraction (RVEF) were measured using a fully automated software (Philips), a semi-automated software (TomTec), and CMR in 100 patients who had undergone both CMR and 3DE examinations on the same day. The feasibility of the fully automated software was 91%. Although the fully automated software, without any manual editing, significantly underestimated RV end-diastolic volume (bias: -12.6 mL, P < 0.001) and stroke volume (-5.1 mL, P < 0.001) compared with CMR, there were good correlations between the two modalities (r = 0.82 and 0.78). No significant differences in RVEF between the fully automated software and CMR were observed, and there was a fair correlation (r = 0.72). The RVEF determined by the semi-automated software was significantly larger than that by CMR or the fully automated software (P < 0.001). The fully automated software had a shorter analysis time compared with the semi-automated software (15 s vs. 120 s, P < 0.001) and had a good reproducibility.

CONCLUSION

A novel, fully automated 3DE RV quantification software underestimated RV volumes but successfully approximated RVEF when compared with CMR. No inferiority of this software was observed when compared with the semi-automated software. Rapid analysis and higher reproducibility also support the routine adoption of this method in the daily clinical workflow.

Sickle cell disease and ventricular myocardial strain: A systematic review

Cardiac disease is the primary cause of death in sickle cell disease (SCD). Cardiac abnormalities begin in childhood and progress throughout life. Right and left ventricular (RV, LV) myocardial strain are early markers of systolic dysfunction but are not well investigated among individuals with SCD. The objectives of this review were to (1) identify all published studies that have evaluated ventricular myocardial strain, (2) summarize their values, and (3) compare findings with those obtained from controls. From search results of four electronic databases-Medline, Embase, Scopus, and Web of Science-42 potential articles were identified, of which 18 articles and 17 studies met eligibility criteria for inclusion. The evaluated studies demonstrate that RV and LV myocardial strain are generally abnormal in individuals with SCD compared with controls, despite having normal ejection/shortening fraction. Myocardial strain has been inconsistently evaluated in this population and should be considered any time an echocardiogram is performed.

Comparison of echocardiographic parameters with cardiac magnetic resonance imaging in the assessment of right ventricular function

INTRODUCTION

The right ventricle (RV) strain measured by speckle tracking (RVS) is an echocardiographic parameter used to assess RV function. We compared RVS to RV fractional area change (FAC%), tricuspid annular plane systolic excursion (TAPSE) and Doppler tissue imaging-derived peak systolic velocity (S') in the assessment of right ventricular (RV) systolic function measured using cardiac magnetic resonance imaging (MRI).

METHODS

We enrolled consecutive patients who underwent cardiac MRI between Jan 2012 and Dec 2017 and a transthoracic echocardiogram (TTE) within 1 month of the MRI with no interval event. Baseline clinical characteristics and MRI parameters were extracted from chart review. Echocardiographic parameters were measured prospectively. TTE parameters including RVS, TAPSE, S', and FAC% were tested for accuracy to identify impaired RV EF (EF < 45% & <30%) using receiver operator curves.

RESULTS

The study cohort included 500 patients with mean age 55 years ± 18 and peak tricuspid regurgitation velocity 2.7 ± 1.4 m/s. The area under ROC for RVS was 0.69 (95% CI 0.63-0.75) and 0.78 (95% CI 0.70-0.88) to predict RVEF < 45% & RVEF < 30%, respectively. The RV FAC% had second highest accuracy of predicting RVEF among all the TTE parameters tested in study.

CONCLUSION

Right ventricular strain is the most accurate echocardiographic method to detect impaired right ventricular systolic function when using MRI as the gold standard.

[Right ventricular function after a first episode of pulmonary embolism: Contribution of longitudinal 2D strain]

BACKGROUND

Analysis of right ventricular (RV) function during the acute phase of pulmonary embolism (PE) was widely reported in the literature. However, few studies analysed its function long term after the acute phase. Our aim was to evaluate the RV function long term after a first episode of PE.

METHODS

In this study, we compared echocardiographic parameters of right ventricular function in 25 patients with a first episode of non-severe PE for more than six months with 25 healthy controls subject.

RESULTS

In the study of RV function, we noted that the mean values of the standard parameters were significantly lower in the EP group compared to the control group but their values remained within the normal range. The global RV longitudinal strain had a mean value lower than the control group statistically significant (-21±4,8% vs. -25±2,4%; P=0,28). The longitudinal strain of the free wall of the RV was altered in the EP group, however, there was no significant difference between the EP group and the control group (-19,4±16% vs. -24±17%; P=0,28).

CONCLUSION

This study has shown that there is a systolic dysfunction late after a first episode of PE and this despite the absence of the symptoms and pulmonary hypertension.

The prognostic role of speckle tracking echocardiography in clinical practice: evidence and reference values from the literature

Speckle tracking echocardiography (STE) is a second-level echocardiographic technique which has gradually gained relevance in the last years. It allows semi-automatic quantification of myocardial deformation and function, overcoming most of the limitations characterizing basic echocardiography and providing an early detection of cardiac impairment. Today, its feasibility and usefulness are highly supported by literature. In particular, several studies demonstrated that STE could provide additional prognostic information beyond conventional echocardiographic and traditional clinical parameters. Moreover, a recent standardization of speckle tracking analysis regarding all cardiac chambers paved the way for the integration of STE in diagnostic and prognostic protocols for particular clinical settings. The aim of this review is to describe the prognostic role of STE in different clinical scenarios basing on currently available evidence.

Prognostication of Poor Survival After Cardiac Resynchronization Therapy

Background and Objectives: Cardiac resynchronization therapy (CRT) is a successful treatment option for appropriately selected patients. However, one–third of recipients do not experience any positive outcome or their condition even declines. We aimed to assess preimplantation factors associated with worse survival after the CRT. Materials and Methods: This was a retrospective unicenter trial. The study cohort included 183 consecutive CRT-treated patients. Baseline demographic, clinical, electrocardiographic, and echocardiographic characteristics were analyzed. Results: After the median follow-up of 15.6 months (9.3–26.3), 20 patients had died (11%). In multivariate Cox regression analysis, ischemic origin of heart failure (HF) was a significant predictor of poor survival (adjusted hazard ratio (aHR) 15.235, 95% confidence interval (CI) (1.999–116.1), p = 0.009). In univariate Cox regression, tricuspid annular plane systolic excursion (TAPSE) <15.5 mm (sensitivity 0.824, specificity 0.526; HR 5.019, 95% CI (1.436–17.539), p = 0.012), post-implantation prescribed antiplatelet agents (HR 2.569, 95% CI (1.060–6.226), p = 0.037), statins (HR 2.983, 95% CI (1.146–7.764), p = 0.025), and nitrates (HR 3.694, 95% CI (1.342–10.171), p = 0.011) appeared to be related with adverse outcome. Conclusions: ischemic etiology of HF is a significant factor associated with worse survival after the CRT. Decreased TAPSE is also related to poor survival.

Right ventricular mechanical pattern in health and disease: beyond longitudinal shortening

Right ventricular (RV) function has proven to be a prognostic factor in heart failure with reduced and preserved ejection fraction and in pulmonary hypertension. RV function is also a cornerstone in the management of novel clinical issues, such as mechanical circulatory support devices or grown-up congenital heart disease patients. Despite the notable amount of circumferentially oriented myofibers in the subepicardial layer of the RV myocardium, the non-longitudinal motion directions are often neglected in the everyday assessment of RV function by echocardiography. However, the complex RV contraction pattern incorporates different motion components along three anatomically relevant axes: longitudinal shortening with traction of the tricuspid annulus towards the apex, radial motion of free wall often referred as the "bellows effect", and anteroposterior shortening of the chamber by stretching the free wall over the septum. Advanced echocardiographic techniques, such as speckle-tracking and 3D echocardiography allow an in-depth characterization of RV mechanical pattern, providing better understanding of RV systolic and diastolic function. In our current review, we summarize the existing knowledge regarding RV mechanical adaptation to pressure- and/or volume-overloaded states and also other physiologic or pathologic conditions.

Prognostic Value of Right Ventricular Dysfunction in Heart Failure With Reduced Ejection Fraction: Superiority of Longitudinal Strain Over Tricuspid Annular Plane Systolic Excursion

BACKGROUND

In heart failure (HF) with reduced ejection fraction, right ventricular (RV) impairment, as defined by reduced tricuspid annular plane systolic excursion, is a predictor of poor outcome. However, peak longitudinal strain of RV free wall (RVFWS) has been recently proposed as a more accurate and sensitive tool to evaluate RV function. Accordingly, we investigated whether RVFWS could help refine prognosis of patients with HF with reduced ejection fraction in whom tricuspid annular plane systolic excursion is still preserved.

METHODS AND RESULTS

A total of 200 patients with HF with reduced ejection fraction (age, 66±11 years; ejection fraction, 30±7%) with preserved tricuspid annular plane systolic excursion (>16 mm) underwent RV function assessment using speckle-tracking echocardiography to measure peak RVFWS. After a median follow-up period of 28 months, 62 (31%) patients reached the primary composite end point of all-cause death/HF rehospitalization. Median RVFWS was -19.3% (interquartile range, -23.3% to -15.0%). By lasso-penalized Cox-hazard model, RVFWS was an independent predictor of outcome, along with Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure-HF score, Echo-HF score, and severe mitral regurgitation. The best cutoff value of RVFWS for prediction of outcome was -15.3% (area under the curve, 0.68; P<0.001; sensitivity, 50%; specificity, 80%). In 50 patients (25%), RVFWS was impaired (ie, ≥-15.3%); event rate (per 100 patients per year) was greater in them than in patients with RVFWS <-15.3% (29.5% [95% confidence interval, 20.4-42.7] versus 9.4% [95% confidence interval, 6.7-13.1]; P<0.001). RVFWS yielded a significant net reclassification improvement (0.584 at 3 years; P<0.001), with 68% of nonevents correctly reclassified.

CONCLUSIONS

In patients with HF with reduced ejection fraction with preserved tricuspid annular plane systolic excursion, RV free-wall strain provides incremental prognostic information and improved risk stratification.

Should the septum be included in the assessment of right ventricular longitudinal strain? An ultrasound two-dimensional speckle-tracking stress study

Right ventricular longitudinal strain (RVLS) by 2D speckle-tracking echocardiography (2D-STE) is a useful parameter for assessing systolic function. However, the exact method to perform it is not well defined as some authors evaluate only free wall (FW) segments while others include all six RV segments. To compare the assessment of RVLS at rest and during exercise by these two approaches. Echocardiography was performed on 80 healthy subjects at rest and during exercise. The analysis consisted of standard and 2D-STE assessment of RV global and segmental strain tracing only RVFW and also tracing all six RV segments. At rest, RVLS could be assessed in 78 (feasibility 97.5%) subjects by both methods. However, during exercise, RVLS by RVFW method was feasible in 67 (83.8%) as compared to 74 (92.5%) by RV6S approach. Both at rest and during exercise, RVLS values by the two methods showed excellent correlation (r =  > 0.90). However, RVLS values assessed by RV6S were lower (absolute values) than those by RVFW approach (RV6S vs. RVFW; rest: - 27.0 ± 3.9 vs. - 9.5 ± 3.9, p < 0.001 and exercise: - 30.7 ± 5.2 vs. - 33.3 ± 5.1, p < 0.001). Furthermore, basal strain was higher and apical strain lower (absolute values) by RV6S approach. At rest, reproducibility for RVLS was excellent and similar for the two methods. However, during exercise, reproducibility for RVFW method was poorer, especially at the apex. The two currently described methods for RVLS assessment by 2D-STE demonstrated excellent agreement. However, the RV6S approach seemed to be more feasible and reproducible, particularly during exercise. Moreover, global and segmental strain values are different with both methods and should not be interchanged.

Superior Prognostic Value of Right Ventricular Free Wall Compared to Global Longitudinal Strain in Patients With Heart Failure

BACKGROUND

Global right ventricular (RV) longitudinal strain (RVGLS) and free wall RV longitudinal strain (RVFWS) have both been advocated as sensitive tools to evaluate RV function and predict prognosis in patients with heart failure and reduced ejection fraction (HFrEF). However, because the interventricular septum is an integral part of the left ventricle (LV) also, RVGLS might be influenced by LV dysfunction. Thus, we compared the prognostic performance of either RV strain parameter in HFrEF patients, also taking into account the degree of LV systolic dysfunction.

METHODS

In 288 prospectively enrolled outpatients with stable HFrEF, RVGLS and RVFWS were assessed by speckle-tracking and LV systolic function by global longitudinal strain and LV ejection fraction. Patients were followed up for 30.2 ± 23.0 months; the primary endpoint was all-cause death/heart failure-related hospitalization. Prognostic performance was assessed by C-statistic and net reclassification improvement.

RESULTS

There were 95 events during follow-up. By univariable analysis, both RVGLS (hazard ratio × 1 SD, 1.60; 95% CI, 1.29-1.99; P < .0001) and RVFWS (hazard ratio × 1 SD, 1.82; 95% CI, 1.45-2.29; P < .0001) were associated with outcome, and both remained significant after correction for EMPHASIS risk score, New York Heart Association class, natriuretic peptides, and therapy. However, after further correction for LV systolic function parameters, only RVFWS remained significantly associated with outcome (P < .01). A basic prediction model was improved by adding RVFWS (net reclassification improvement 0.390; P < .05), but not RVGLS.

CONCLUSIONS

Although both RVGLS and RVFWS have prognostic value, RVFWS better predicts outcome in HFrEF patients, mainly because it is less influenced by LV longitudinal dysfunction.

Ventricular global longitudinal strain is altered in children with sickle cell disease

Cardiac disease is the primary cause of death in sickle cell disease (SCD). Right and left ventricular global longitudinal strain (RVGLS, LVGLS) are early markers of systolic dysfunction but are not well investigated among children with SCD. One hundred and forty-three patients with HbSS or HbSβ⁰ -thalassaemia (median age 11 years, range 5-19 years) and 71 controls matched for age and sex were compared. RVGLS and LVGLS were measured and compared with conventional measures of echocardiography and markers of haemolysis and inflammation. RVGLS was higher in children with SCD than in controls (-25·72% ± 3·45% vs. -24·54% ± 2·41%, P = 0·005); LVGLS was not different. RVGLS decreased with older age in children with SCD (ρ = 0·338, P < 0·001) but not among controls. Decreased RVGLS was associated with increased left atrial end diastolic volume (ρ = 0·181, P = 0·04); RVGLS increased with cardiac output (r = -0·279, P = 0·01). RVGLS and LVGLS were not associated with disease-modifying therapies, degree of anaemia or haemolysis markers. Elevated RVGLS may indicate an early RV compensatory mechanism in response to upstream myocardial insults and elevated cardiac output. Global longitudinal strain may serve as an early marker of altered myocardial function in children with SCD.

Echocardiography for the management of patients with biventricular pacing: Possible roles in cardiac resynchronization therapy implementation

Cardiac resynchronization therapy (CRT) is an established therapeutic option for the subset of patients with heart failure (HF), reduced ejection fraction (EF), and dyssynchrony evidenced by electrocardiography. Benefit from CRT has been proven in many clinical trials, yet a sizeable proportion of these patients with wide QRS do not respond to this intervention, despite the updated practice guidelines. Several echocardiographic indices, targeting mechanical rather than electrical dyssynchrony, have been suggested to address this issue, but research so far has not succeeded in providing a single and simple measurement with adequate sensitivity and specificity for identification of responders. While there is still ongoing research in this field, echocardiography proves helpful in other aspects of CRT implementation, such as site selection for left ventricular (LV) lead pacing and optimization of pacing parameters during follow-up visits.

Sex-specific mortality differences in heart failure patients with ischemia receiving cardiac resynchronization therapy

Background

Recent studies have reported prognosis differences between male and female heart failure patients following cardiac resynchronization therapy (CRT). However, the potential clinical factors that underpin these differences remain to be elucidated.

Methods

A meta-analysis was performed to investigate the factors that characterize sex-specific differences following CRT. This analysis involved searching the Medline (Pubmed source) and Embase databases in the period from January 1980 to September 2016.

Results

Fifty-eight studies involving 33445 patients (23.08% of whom were women) were analyzed as part of this study. Only patients receiving CRT with follow-up greater than six months were included in our analysis. Compared with males, females exhibited a reduction of 33% (hazard ratio, 0.67; 95% confidence interval, 0.62–0.73; P < 0.0001) and 42% (hazard ratio, 0.58; 95% confidence interval, 0.46–0.74; P = 0.003) in all-cause mortality and heart failure hospitalization or heart failure, respectively. Following a stratified analysis of all-cause mortality, we observed that ischemic causes (p = 0.03) were likely to account for most of the sex-specific differences in relation to CRT.

Conclusion

These data suggest that women have a reduced risk of all-cause mortality and heart failure hospitalization or heart failure following CRT. Based on the results from the stratified analysis, we observed more optimal outcomes for females with ischemic heart disease. Thus, ischemia are likely to play a role in sex-related differences associated with CRT in heart failure patients. Further studies are required to determine other indications and the potential mechanisms that might be associated with sex-specific CRT outcomes.

Assessment of right ventriclular systolic function prior to cardiac resynchronization therapy: Does it make any difference?

Background

Cardiac resynchronization therapy (CRT) is an effective treatment for patients with advanced heart failure (HF). Nearly 30% of candidates are inadequate responders. The benefit of patients with right sided heart failure from CRT is still a matter of debate. We examined the effect of CRT on right ventricular (RV) dimensions and overall systolic function and whether RV function prior to CRT could have an impact on CRT response.

Methods

94 patients with a mean age of 53.7 ± 14.6 years including 19 (20%) females, with advanced HF (EF < 35%, LBBB > 120 ms, or non-LBBB > 150 ms, with NYHA –III or ambulatory class IV) were enrolled and underwent CRT implantation. Standard two dimensional (2D) echocardiography, tissue Doppler imaging, for assessment of Left ventricular (LV) end-diastolic (LVEDV), and end-systolic volumes (LVESV), ejection fraction, RV maximum basal (RVD basal), maximum mid (RVD mid) transverse, maximum longitudinal (RVD long) diameters, TAPSE, fractional area change (FAC), and tricuspid lateral annular systolic velocity (S′), in addition to RV global longitudinal strain (RVGLS) measured by speckle tracking echocardiography, were done before CRT implantation and at the end of the follow up period (5.9 ± 1.2 months). Patients presenting with reductions of LVESV of >15% were termed volumetric responders for further statistical analysis.

Results

63 (67%) cases were volumetric responders. Both groups were matched regarding demographic, clinical, ECG, and echocardiographic criteria apart from the RV significantly smaller transverse diameters and significantly better systolic function parameters in the responders group prior to CRT compared to non-responders (NR) group. At the end of the follow up, only the responders group had further significant reduction in RV basal, mid and longitudinal diameters (33.6 ± 7.1 vs 40.7 ± 8.6, 21.4 ± 4.9 vs 27 ± 6.1, 68.3 ± 10.8 vs 81.2 ± 15, respectively), p < 0.01, together with significant improvement in RV systolic performance: FAC (47.7 ± 7.3 vs 40.9 ± 6.4), TAPSE (25.2 ± 4.6 vs 22.1 ± 4.9), S′ (15.3 ± 2.3 vs 12.8 ± 2.3), and GLS (26.1 ± 2.1 vs 18.5 ± 1.6), P < 0.01, compared to baseline readings. S' and GLS were the only independent predictors of CRT response by multivariate analysis. S′ >9 cm/s, and GLS >12.45% had 100% sensitivity and 70%, 99.7% specificity, respectively for prediction of response to CRT.

Conclusions

CRT induces RV reverse remodeling and improves RV systolic function particularly in cardiac volumetric responders. RV systolic dysfunction before CRT implantation could identify patients that might not benefit from CRT thus helping proper patient selection and optimizing CRT response.

Quantification of the relative contribution of the different right ventricular wall motion components to right ventricular ejection fraction: the ReVISION method

Three major mechanisms contribute to right ventricular (RV) pump function: (i) shortening of the longitudinal axis with traction of the tricuspid annulus towards the apex; (ii) inward movement of the RV free wall; (iii) bulging of the interventricular septum into the RV and stretching the free wall over the septum. The relative contribution of the aforementioned mechanisms to RV pump function may change in different pathological conditions.

Our aim was to develop a custom method to separately assess the extent of longitudinal, radial and anteroposterior displacement of the RV walls and to quantify their relative contribution to global RV ejection fraction using 3D data sets obtained by echocardiography.

Accordingly, we decomposed the movement of the exported RV beutel wall in a vertex based manner. The volumes of the beutels accounting for the RV wall motion in only one direction (either longitudinal, radial, or anteroposterior) were calculated at each time frame using the signed tetrahedron method. Then, the relative contribution of the RV wall motion along the three different directions to global RV ejection fraction was calculated either as the ratio of the given direction’s ejection fraction to global ejection fraction and as the frame-by-frame RV volume change (∆V/∆t) along the three motion directions.

The ReVISION (Right VentrIcular Separate wall motIon quantificatiON) method may contribute to a better understanding of the pathophysiology of RV mechanical adaptations to different loading conditions and diseases.

Added clinical value of applying myocardial deformation imaging to assess right ventricular function

Right heart dysfunction has been found to be a strong prognostic factor predicting adverse outcome in various cardiopulmonary diseases. Conventional echocardiographic measurements can be limited by geometrical assumptions and impaired reproducibility. Speckle tracking-derived strain provides a robust quantification of right ventricular function. It explicitly evaluates myocardial deformation, as opposed to tissue Doppler-derived strain, which is computed from tissue velocity gradients. Right ventricular longitudinal strain provides a sensitive tool for detecting right ventricular dysfunction, even at subclinical levels. Moreover, the longitudinal strain can be applied for prognostic stratification of patients with pulmonary hypertension, pulmonary embolism, and congestive heart failure. Speckle tracking-derived right atrial strain, right ventricular longitudinal strain-derived mechanical dyssynchrony, and three-dimensional echocardiography-derived strain are emerging imaging parameters and methods. Their application in research is paving the way for their clinical use.

Clinical utility of speckle-tracking echocardiography in cardiac resynchronisation therapy

Cardiac resynchronisation therapy (CRT) can profoundly improve outcome in selected patients with heart failure; however, response is difficult to predict and can be absent in up to one in three patients. There has been a substantial amount of interest in the echocardiographic assessment of left ventricular dyssynchrony, with the ultimate aim of reliably identifying patients who will respond to CRT. The measurement of myocardial deformation (strain) has conventionally been assessed using tissue Doppler imaging (TDI), which is limited by its angle dependence and ability to measure in a single plane. Two-dimensional speckle-tracking echocardiography is a technique that provides measurements of strain in three planes, by tracking patterns of ultrasound interference ('speckles') in the myocardial wall throughout the cardiac cycle. Since its initial use over 15 years ago, it has emerged as a tool that provides more robust, reproducible and sensitive markers of dyssynchrony than TDI. This article reviews the use of two-dimensional and three-dimensional speckle-tracking echocardiography in the assessment of dyssynchrony, including the identification of echocardiographic parameters that may hold predictive potential for the response to CRT. It also reviews the application of these techniques in guiding optimal LV lead placement pre-implant, with promising results in clinical improvement post-CRT.