Prediction of stroke volume by global left ventricular longitudinal strain in patients undergoing assessment for cardiac transplantation

Global longitudinal strain is an informative index of left ventricular performance in neonates receiving intensive care

Echocardiographic assessment of left ventricular function is crucial in NICU. The study aimed to compare the accuracy and agreement of global longitudinal strain (GLS) with conventional measurements. Real-life echocardiograms of neonates receiving intensive care were retrospectively reviewed. Shortening fraction (SF), ejection fraction (EF) and S' measurements were retrieved from health records. GLS was calculated offline from stored images. The association with stroke volume indexed for body weight (iSV) was evaluated by regression analysis. The diagnostic ability to identify uncompensated shock was assessed by ROC curve analysis. Cohen's κ was run to assess agreement. 334 echocardiograms of 155 neonates were evaluated. Mean ± SD gestational age and birth weight were 34.5 ± 4.1 weeks and 2264 ± 914 g, respectively. SF, EF, S' and GLS were associated with iSV with R2 of 0.133, 0.332, 0.252 and 0.633, (all p < .001). Including all variables in a regression model, iSV prediction showed an adjusted R2 of 0.667, (p < .001). GLS explained 73% of the model variance. GLS showed a better ability to diagnose uncompensated shock (AUC 0.956) compared to EF, S' and SF (AUC 0.757, 0.737 and 0.606, respectively). GLS showed a moderate agreement with EF (κ = .500, p < .001) and a limited agreement with S' and SF (κ = .260, p < .001, κ = .242, p < .001). GLS was a more informative index of left ventricular performance, providing the rationale for a more extensive use of GLS at the cotside.

Neurocognitive impairment associated with chronic morbidity in long-term survivors of Hodgkin Lymphoma

Thoracic radiation is associated with significant cardiopulmonary morbidities in survivors of long-term Hodgkin lymphoma and may affect neurocognitive outcomes. Survivors (N = 204; 52.5% female; mean [standard deviation] age, 36.6 [8.01] years) treated with thoracic radiation and age-, sex-, and race/ethnicity-matched community controls (N = 205; 51.7% female; age, 36.7 [9.17] years) completed standardized neurocognitive testing, echocardiography, pulmonary function tests, and vascular studies during the same visit. Treatments were abstracted from medical records. Cardiac (ie, left ventricular ejection fraction [LVEF], global longitudinal strain [GLS]), vascular (ie, large and small artery elasticity [SAE]), pulmonary (ie, diffusing capacity of the lungs for carbon monoxide [DLCO] and forced expiratory volume [FEV1]), and chronic health conditions were evaluated for associations with age-adjusted neurocognitive performance using multivariable linear regression. Compared with controls, survivors had lower performance (P < 0.05) in visuomotor (0.11 vs 0.41), visual processing speed (0.25 vs 0.64), short-term recall (-0.24 vs 0.12), and flexibility (-0.04 vs 0.28). Survivors had lower pulmonary (FEV1, DLCOcorr), cardiac (LVEF, GLS), and vascular function (SAE) than controls (all P < 0.001). FEV1 was associated with visuomotor (P = .008) and visual processing speed (P = .05), and flexibility (P = .05). GLS was associated with short-term recall (P = .03). SAE was associated with flexibility (P = .007). Neurocognitive outcomes were also associated with moderate-to-severe neurologic chronic conditions (P < .05). Findings suggest a link between subclinical cardiopulmonary and vascular findings, neurologic morbidity, and neurocognitive impairments. Prevention of health morbidity may benefit neurocognitive outcomes.

The Use of Global Longitudinal Strain to Detect Subclinical Reduction in Left Ventricular Pump Function

BACKGROUND

Left ventricular (LV) ejection fraction (LVEF) is not a sensitive marker of LV systolic function in a subset of patients with preserved EF. The relation between LV pump function and global longitudinal strain (GLS) has not been elucidated well in patients with objectively preserved EF and no apparent heart failure (HF). We aimed to detect whether LV GLS can discover impaired LV pump function [presented as low stroke volume index (SVI) and low cardiac output (COP)] in patients with objectively preserved EF and no apparent clinical HF and its practice utility.

METHODS

In total, 100 participants with LVEF of ≥50% were studied for demographic and echocardiographic data, including LVEF, stroke volume, SVI, COP, LV longitudinal strain assessments, apical 4-, 3-, and 2-chamber views averaged for GLS, and were classified into 2 groups: group 1: normal GLS (more negative than -18%) and group 2: low GLS (less negative than -18%).

RESULTS

Reduced LV GLS was associated with lower SVI (35.6 ± 13.6 vs. 43.8 ± 12.7 mL/m 2 ; P = 0.01), lesser COP (5.4 ± 1.9 vs. 6.5 ± 2.1 l/min; P = 0.02), GLS had strong positive correlations with SVI ( r = 0.75; P < 0.001), and COP ( r = 0.66; P < 0.001). LV GLS at a cutoff value less negative than -15% is a strong predictor of SVI ≤35 mL/m 2 (76% sensitivity and 79% specificity) and at a cutoff value less negative than -13.5% it is a strong predictor of COP ≤4 L/min (76% sensitivity and 73% specificity). LV GLS was the best independent predictor of low SVI (<35 mL/m 2 ) and low COP (<4 L/min).

CONCLUSION

Impaired LV strain is associated with lower LV pump function, presented as lower COP and lower SVI in patients with preserved EF even in the absence of clinical HF. It is of great importance to incorporate GLS in the routine evaluation of LV function hand-by-hand with the noninvasive assessment of LV stroke volume and COP that can replace GLS on evaluation of LV pump function in old machines with no GLS modalities, for early pick-up of patients with impaired LV pump function before apparent HF.

Usefulness and clinical relevance of left ventricular global longitudinal systolic strain in patients with heart failure with preserved ejection fraction

In recent years, several studies have shown the usefulness and clinical relevance of left ventricular global longitudinal systolic strain (GLS) in different cardiovascular diseases. In line with this, the role of GLS in patients with heart failure with preserved ejection fraction (HFpEF) has achieved great importance in this predominant form of heart failure in the last years. In this regard, GLS has shown to be not only a sensitive parameter to detect subtle myocardial abnormalities but also a parameter of clinical and prognostic relevance in patients with HFpEF. In this review, we analyze the current evidence concerning the clinical relevance of GLS in patients with HFpEF and we discuss the potential usefulness of GLS in this complex and heterogeneous condition for which so far no effective therapy exists.

Defining the left ventricular base in mitral valve prolapse: impact on systolic function and regurgitation

In bileaflet mitral valve prolapse (BMVP) systolic leaflet displacement creates a pocket of blood on the left ventricular (LV) side of the leaflets, but on the atrial side of the annulus. This blood is excluded from the LV end-systolic volume if the mitral valve annulus is used to determine the most basal extent of the LV. The purpose of this study is to describe the quantitative implications of defining the LV base on mitral regurgitant severity and LV systolic function in BMVP. In 30 consecutive patients (53% male, 58 ± 14 years) with BMVP, LV endocardial and epicardial borders were determined from SSFP images. The LV base at end-systole was defined by the "Functional" method (at the mitral valve annulus) or the "Anatomic" method (at the mitral valve leaflets). Regurgitant volume was the difference between the LV stroke volume and mean forward flow. LV myocardial strain measurements were determined from the short axis endocardial and epicardial borders. The "Functional" method resulted in higher regurgitant volumes (mean difference: 22 ml, range 0-40 ml) and higher ejection fractions (mean difference: 9%, range 0-21%). The correlation between LV end-diastolic volume and regurgitant volume was better with the "Functional" method (r = 0.79, p < 0.0001) than the "Anatomic" method (r = 0.67, p < 0.0001). The correlation between global myocardial radial strain and LV EF was better with the "Functional" method (r = 0.86, p < 0.0001) than the "Anatomic" method (r = 0.68, p < 0.0001). In BMVP, the base of the LV should be defined at the level of the mitral valve annulus so that regurgitant volume most accurately reflects the functional significance of the mitral valve disease and LVEF most accurately reflects global systolic LV function. Defining the basal extent of the LV at the mitral valve leaflets leads to substantially lower regurgitant volumes and lower ejection fractions that could have important clinical consequences.

Subclinical Compromise in Cardiac Strain Relates to Lower Cognitive Performances in Older Adults

BACKGROUND

Global longitudinal strain (GLS), reflecting total shortening of the myocardium during the cardiac cycle, has emerged as a more precise myocardial function measure than left ventricular ejection fraction (LVEF). Longitudinal strain may be selectively affected in subclinical heart disease, even in the presence of normal LVEF. This study examines subclinical cardiac dysfunction, assessed by GLS and LVEF, and cognition among older adults.

METHODS AND RESULTS

Vanderbilt Memory and Aging Project participants who were free of clinical dementia, stroke, and heart failure (n=318, 73±7 years, 58% male) completed neuropsychological assessment and cardiac magnetic resonance to quantify GLS and LVEF. Linear regression models related GLS and LVEF to neuropsychological performances, adjusting for age, sex, race/ethnicity, education, Framingham Stroke Risk Profile, cognitive diagnosis, and APOE*ε4 status. Models were repeated with a cardiac×cognitive diagnosis interaction term. Compromised GLS (reflected by higher values) related to worse naming (β=-0.07, P=0.04), visuospatial immediate recall (β=-0.83, P=0.03), visuospatial delayed recall (β=-0.22, P=0.03), and verbal delayed recall (β=-0.11, P=0.007). LVEF did not relate to worse performance on any measure (P>0.18). No diagnostic interactions were observed.

CONCLUSIONS

Our study results are among the first to suggest that compromised GLS relates to worse episodic memory and language performance among older adults who are free of clinical dementia, stroke, and heart failure. Subclinical cardiac dysfunction may correlate with cognitive health in late life, even when LVEF remains normal. The results add to growing evidence that GLS may be a more sensitive and preferred method for quantifying subclinical changes in cardiac function.

Echocardiographic assessment of the right ventricle: Impact of the distinctly load dependency of its size, geometry and performance

Right ventricular (RV) size, shape and function are distinctly load-dependent and pulmonary load is an important determinant of RV function in patients with congestive heart failure (CHF) due to primary impaired left ventricular function and in those with pre-capillary pulmonary hypertension (PH). In a pressure overloaded RV, not only dilation and aggravation of tricuspid regurgitation, but also systolic dysfunction leading to RV failure (RVF) can occur already before the development of irreversible alterations in RV myocardial contractility. This explains RV ability for reverse remodeling and functional improvement in patients with post-capillary and pre-capillary PH of a different etiology, after normalization of loading conditions. There is increasing evidence that RV evaluation by echocardiography in relation with its loading conditions can improve the decision-making process and prognosis assessments in clinical praxis. Recent approaches to evaluate the RV in relation with its actual loading conditions by echo-derived composite variables which either incorporate a certain functional parameter (i.e. tricuspid annulus peak systolic excursion, stroke volume, RV end-systolic volume index, velocity of myocardial shortening) and load, or incorporate measures which reflect the relationship between RV load and RV dilation, also taking the right atrial pressure into account (i.e. "load adaptation index"), appeared particularly suited and therefore also potentially useful for evaluation of RV contractile function. Special attention is focused on the usefulness of RV echo-evaluation in relation to load for proper decision making before ventricular assist-device implantation in patients with CHF and for optimal timing of listing procedures to transplantation in patients with end-stage pre-capillary PH.

Comparison of right versus left ventricular strain analysis as a predictor of outcome in patients with systolic heart failure referred for heart transplantation

The aim of the present study was to explore the relation between right ventricular (RV) and left ventricular (LV) echocardiographic parameters with clinical outcome in patients with advanced heart failure referred for cardiac transplantation. Ninety-eight consecutive patients with advanced systolic heart failure, referred for cardiac transplant evaluation, were enrolled. All patients were prospectively followed for the development of new outcome events, which included hospitalization for acute heart failure, cardiovascular death, heart transplantation, intra-aortic balloon pump implantation, and ventricular assist device implantation. Conventional transthoracic echocardiography was performed in all subjects. RV longitudinal strain (RVLS) by speckle-tracking echocardiography was assessed by averaging all segments in apical 4-chamber view (global RVLS) and by averaging RV free-wall segments (free-wall RVLS). LV global longitudinal and global circumferential strains were also calculated. Of the 98 subjects at baseline, 46 had 67 new events during a mean follow-up of 1.5 ± 0.9 years. Free-wall RVLS, global RVLS, N-terminal fragment of the prohormone brain natriuretic peptide, RV fractional area change, and LV end-diastolic volume were independently predictive of combined outcomes (all p <0.0001). The overall performance for the prediction of cardiovascular events was greatest for free-wall RVLS (area under the curve free-wall RVLS: 0.87; global RVLS: 0.67; RV fractional area change: 0.60; N-terminal fragment of the prohormone brain natriuretic peptide, 0.62; global circumferential strain: 0.55; global longitudinal strain: 0.35; and LV ejection fraction: 0.26). Free-wall RVLS showed the highest adjusted hazards ratio. A graded association between the grade of RV dysfunction and the risk of cardiovascular events was only evident for free-wall RVLS and global RVLS. In conclusion, in patients referred for heart transplantation, RVLS is a stronger predictor of outcome than LV longitudinal strain and other conventional parameters, providing a stronger prognostic stratification.

Right ventricular longitudinal strain correlates well with right ventricular stroke work index in patients with advanced heart failure referred for heart transplantation

BACKGROUND

Right ventricular (RV) systolic function has a critical role in determining the clinical outcome and success of using left ventricular assist devices (LVADs) in patients with refractory heart failure. Tissue Doppler and M-mode measurements of tricuspid systolic motion (tricuspid S' and tricuspid annular plane systolic excursion [TAPSE]) are the most currently used methods for the quantification of RV longitudinal function; RV deformation analysis by speckle-tracking echocardiography (STE) has recently allowed the analysis of global RV longitudinal function. Using cardiac catheterization as the reference standard, this study aimed at exploring the correlation between RV longitudinal function by STE and RV stroke work index (RVSWI) in patients referred for cardiac transplantation.

METHODS AND RESULTS

Right-side heart catheterization and transthoracic echo Doppler were simultaneously performed in 41 patients referred for cardiac transplantation evaluation for advanced systolic heart failure. Thermodilution RV stroke volume and invasive pulmonary pressures were used to obtain RVSWI. RV longitudinal strain (RVLS) by STE was assessed averaging all segments in apical 4-chamber view (global RVLS) and by averaging RV free-wall segments (free-wall RVLS). Tricuspid S' and TAPSE were also calculated. No significant correlations were found for TAPSE or tricuspid S' with RVSWI (r = 0.14; r = 0.06; respectively). Close negative correlations between global RVLS and free-wall RVLS with the RVSWI were found (r = -0.75; r = -0.82; respectively; both P < .0001). Furthermore, free-wall RVLS demonstrated the highest diagnostic accuracy (area under the receiver operating characteristic (ROC) curve 0.90) and good sensitivity and specificity of 92% and 86%, respectively, to predict depressed RVSWI using a cutoff value of less than -11.8%.

CONCLUSIONS

In a group of patients referred for heart transplantation, TAPSE and tricuspid S' did not correlate with invasively obtained RVSWI. RV longitudinal deformation analysis by STE correlated well with RVSWI, providing a better estimation of RV systolic performance.

Echocardiographic evaluation of the single right ventricle in congenital heart disease: results of new techniques

Right ventricular (RV) function is increasingly recognized as having prognostic significance in various disease processes. The current gold standard for noninvasive measurement of RV function is cardiac magnetic resonance imaging; however, because of practical considerations, echocardiography remains the most often used modality for evaluating the RV. In the past, because of its complex morphology, echocardiographic assessment of the RV was usually qualitative in nature. Current advances in echocardiographic techniques have been able to overcome some of the previous limitations and thus quantification of RV function is increasingly being performed. In addition, recent echocardiographic guidelines for evaluating the RV have been published to aid in standardizing practice. The evaluation of RV function almost certainly has no greater importance than in the congenital heart population, especially in those patients that have a single RV acting as the systemic ventricle. As this complex population continues to increase in number, accurate and precise evaluation of RV function will be a major issue in determining clinical care.