Addition Of Global Longitudinal Strain Research Articles

Prognostic value of myocardial flow reserve in patients with heart failure with preserved ejection fraction

Aim. To study the prognostic value of myocardial blood flow (MBF) and myocardial flow reserve (MFR) parameters in patients with heart failure with preserved ejection fraction (HFpEF) and non-obstructive coronary artery disease (CAD) in risk stratification of HFpEF progression during a 12-month follow-up.Materials and methods. The study included 58 patients with non-obstructive CAD and HFpEF (LVEF 62 [58; 66]%). Dynamic CZT-SRECT was used to evaluate MFR and MBF at rest (rest-MBF) and stress (stress-MBF). NT-proBNP levels were determined by the enzyme immunoassay. Diastolic dysfunction parameters were measured using 2D transthoracic echocardiography. Left ventricular systolic global longitudinal strain (GLS) was assessed using 2D speckle tracking.Results. After a 12-month follow-up, the patients were retrospectively divided into 2 groups: group 1 (n = 11) included patients with an unfavorable course of HFpEF, group 2 (n = 47) encompassed patients with a favorable course of the disease. In group 1, the level of NT-proBNP was 3.8 times higher than in group 2 (284.5 [183.42; 716.73] and 1,071.4 [272.4; 2,168.1] pg / ml, respectively). MFR values in group 1 were lower by 45.4%(p < 0.001) than in group 2 (1.19 [0.86; 1.55] vs. 2.18 [1.7; 2.55], respectively). In group 1, rest-MBF levels were higher by 23.6% (p = 0.046) and stress-MBF was lower by 28.2% (p = 0.046) than in group 2. The multivariate regression analysis revealed that NT-proBNP levels (odds ratio (OR) 3.23; p = 0.008), GLS (OR 2.27; p = 0.012), and MFR (OR 8.09; p < 0.001) were independent predictors of adverse outcomes in HFpEF. Based on the ROC analysis, MFR levels ≤ 1.62 (AUC = 0.827; p < 0.001), GLS ≤–18 (AUC = 0.756; p = 0.002), and NT-proBNP≥ 760.5 pg / ml (AUC = 0.708; p = 0.040) may be considered as markers of adverse outcomes. However, the combined determination of NT-proBNP and MFR had a greater significance (AUC 0.935; p < 0.001) in risk stratification compared with the monomarker model, while the addition of GLS did not increase the significance of the analysis.Conclusion. Levels of NT-proBNP, GLS, and MFR may be used as non-invasive markers of an adverse course of HFpEF in patients with non-obstructive CAD, while the combined determination of NT-proBNP and MBF increases the prognostic value of the analysis.

Abstract 10950: Prognostic Utility of Left Atrio-Ventricular Deformation Analysis in Heart Failure Patients Underwent Cardiac Resynchronization Therapy

Introduction: Left atrial (LA) adverse remodeling is a prognostic marker in patients with heart failure. Although left ventricular (LV) deformation analysis by speckle tracking method has been shown as a useful predictive marker after cardiac resynchronization therapy (CRT), the prognostic impact of baseline left atrio-ventricular functional deterioration on the outcome of patients underwent CRT implantation. Hypothesis: We hypothesized that a combination of LV and LA deformation assessments by speckle-tracking strain is of additive prognostic value in patients with CRT. Methods: We retrospectively analyzed 71 participants who received CRT implantation in the clinical guidelines. Global longitudinal strain (GLS) was defined as averaged strain from 3 apical views. LA strain (LAS) was calculated as the average strain using apical two- and four-chamber views. The endpoint was composite outcome of death, hospitalization due to worsening HF for 5 years after CRT implantation. Results: Out of 71 patients aged 68 ± 11 years with 162±24ms of QRS duration and 30±8% of LV ejection fraction, 40 patients (56%) met the endpoint. The patients were stratified using median value of LAS (-15%) and GLS (-8%). LAS and GCS remained significantly associated with poor outcome after adjusting for LVEF (LAS hazard ratio, 0.92; p<0.001; GLS hazard ratio, 1.15; p = 0.01). Kaplan-Meier analysis showed that the subgroup of patients with both lower median values of LAS and GLS had the worst outcomes over 5 years (Figure, Log-rank, p = 0.008). In the sequential Cox model, predictive value of baseline LV ejection fraction (χ2 = 4.9) was improved by the addition of GLS (χ2 = 9.2, p = 0.037), and further improved by the addition of LAS (χ2 = 15.8, p = 0.005). C-statistics also improved from 0.62 to 0.73. Conclusions: Baseline left atrio-ventricular functional deterioration by deformation analysis were significantly associated with poor outcome after CRT implantation.

Incremental value of global longitudinal strain to predict stress echocardiography positivity in asymptomatic diabetic patients

French guideline recently added the presence of an “abnormal left ventricle” on transthoracic echocardiography (TTE) to define very high-risk diabetic patients who may benefit from silent coronary artery disease (CAD) screening. We aimed to investigate the incremental value of resting Global Longitudinal Strain (GLS) in predicting stress TTE positivity in asymptomatic patients with diabetes mellitus (DM). Consecutive asymptomatic patients with DM referred for screening for silent CAD by stress TTE (effort of dobutamine) between January 2017 and December 2018 were included ( n = 273). Stress test positivity was defined as stress-induced new or worsening of preexisting left ventricular wall motion abnormalities. Patients with a positive stress test ( n = 28; 10%) were more likely to be smokers (71% vs. 17%), to have known diabetes for more than 10 years, carotid atheroma, diabetic nephropathy, diabetic retinopathy (57.1% vs. 18.0%), moderate or severe aortic or mitral calcifications and a lower GLS (−16.7 ± 2.9 vs. −18.9 ± 2.2%) than those with a negative test (all P ≤ 0.014). On multivariate logistic regression analysis, a DM duration > 10 years, diabetic retinopathy and lower GLS (OR [95% CI] = 0.76 [0.64–0.93] per % decrease) remained independently associated with a positive stress TTE. The Chi 2 of the model was significantly improved by the addition of GLS on top of the baseline clinical variables, repolarization abnormalities and DM related complications (Chi 2 56.9 to 73.8; P < 0.001) ( Table 1 , Fig. 1 ). Screening CAD in asymptomatic patients with DM is challenging and debated. In this context, it is crucial to identify early markers of CAD in this population. Our study shows that GLS is strongly associated with the presence of silent ischemia and could be one of these new parameters to be routinely assessed in this population.

Association of left ventricular longitudinal myocardial function with subclinical right ventricular dysfunction in type 2 diabetes mellitus

BackgroundLeft ventricular (LV) involvement in diabetic cardiomyopathy has been reported; however, only limited data exist on right ventricular (RV) involvement. Therefore, our purpose was to investigate RV systolic dysfunction and its association with LV longitudinal myocardial dysfunction in patients with type 2 diabetes mellitus (T2DM) and preserved LV ejection fraction (LVEF).MethodsWe studied 177 T2DM patients with preserved LVEF and 79 age-, sex-, and LVEF-matched healthy volunteers. LV longitudinal myocardial function was assessed as global longitudinal strain (GLS), and RV systolic function was assessed as RV free-wall strain, and predefined cutoff values for subclinical dysfunction were set at GLS < 18% and RV free-wall strain < 20%, respectively.ResultsRV free-wall strain in T2DM patients was significantly lower than that in normal controls (19.3% ± 4.8% vs. 24.4% ± 5.1%; P < 0.0001). RV free-wall strain in T2DM patients and LV longitudinal dysfunction was similar compared to that in T2DM patients without (19.0 ± 4.5% vs. 19.6 ± 5.0%, P = 0.40). Furthermore, multivariate logistic regression analyses showed that GLS was independently associated with RV systolic dysfunction as well as mitral inflow E and mitral e′ annular velocities ratio (odds ratio, 1.16; 95% confidence interval: 1.03–1.31; P < 0.05). Sequential logistic models evaluating the association of RV systolic dysfunction in T2DM patients showed an improvement in clinical variables (χ2 = 6.2) with the addition of conventional echocardiographic parameters (χ2 = 13.4, P < 0.001) and a further improvement with the addition of GLS (χ2 = 20.8, P < 0.001).ConclusionRV subclinical systolic dysfunction was observed in T2DM patients with preserved LVEF and was associated with LV longitudinal myocardial dysfunction. Our findings may provide additional findings for the management of T2DM patients.

Feature-Tracking Global Longitudinal Strain Predicts Mortality in Patients With Preserved Ejection Fraction: A Multicenter Study

ObjectivesThe goal of this study was to evaluate the prognostic value of global longitudinal strain (GLS) derived from cardiac magnetic resonance (CMR) feature-tracking in a large multicenter population of patients with preserved ejection fraction. BackgroundEjection fraction is the principal parameter used clinically to assess cardiac mechanics and provides prognostic information. However, significant abnormalities of myocardial deformation can be present despite preserved ejection fraction. CMR feature-tracking techniques now allow assessment of strain from routine cine images, without specialized pulse sequences. Whether abnormalities of strain measured by using CMR feature-tracking have prognostic value in patients with preserved ejection fraction is unknown. MethodsConsecutive patients with preserved ejection fraction (≥50%) and a clinical indication for CMR at 4 U.S. medical centers were included in this retrospective study. Feature-tracking GLS was calculated from 3 long-axis cine views. The primary endpoint was all-cause death. Cox proportional hazards regression modeling was used to examine the independent association between GLS and death. The incremental prognostic value of GLS was assessed in nested models. ResultsOf the 1,274 patients in this study, 115 died during a median follow-up of 6.2 years. By Kaplan-Meier analysis, patients with GLS ≥ median (–20%) had significantly reduced event-free survival compared with those with GLS < median (log-rank test, p < 0.001). By Cox multivariable regression modeling, each 1% worsening in GLS was associated with a 22.8% increased risk of death after adjustment for clinical and imaging risk factors (hazard ratio: 1.228 per percent; p < 0.001). Addition of GLS in this model resulted in significant improvement in the global chi-square test (94 to 183; p < 0.001) and Harrell’s C-statistic (0.75 to 0.83; p < 0.001). ConclusionsGLS derived from CMR feature-tracking is a powerful independent predictor of mortality in patients with preserved ejection fraction, incremental to common clinical and imaging risk factors.

3225Global longitudinal strain measured using feature-tracking cardiac magnetic resonance imaging is an independent predictor of all cause mortality in patients with preserved ejection fraction

Abstract Introduction Ejection fraction is the principal measure used clinically to assess cardiac mechanics and provides significant prognostic information. However, echocardiographic strain imaging has shown significant abnormalities of myocardial deformation can be present despite preserved ejection fraction, which maybe associated with adverse prognosis. Cardiac-Magnetic-Resonance (CMR) feature-tracking techniques now allow assessment of strain from routine cine-images, without specialized pulse sequences. Whether abnormalities of strain measured using CMR feature-tracking have prognostic value in patients with preserved ejection fraction is unknown. Purpose To evaluate the prognostic value of CMR feature-tracking derived global longitudinal strain (GLS) in a large multicenter population of patients with preserved ejection fraction. Methods Consecutive patients with preserved ejection fraction (EF ≥50%) and a clinical indication for CMR at four US medical centers were included in this study. Feature-tracking GLS was calculated from 3 long-axis-cine-views. The primary endpoint was all-cause death. Cox proportional hazards regression modeling was used to examine the independent association between GLS and death. The incremental prognostic value of GLS was assessed in nested models. Results Of the 1274 patients in this study, 115 died during a median follow-up of 6.2 years. By Kaplan-Meier analysis, patients with GLS ≥ median (−20%) had significantly reduced event free survival compared to those with GLS &lt; median (log-rank p&lt;0.001) (Figure, top panel). The continuous relationship between GLS and the hazard of death is shown in the cubic spline (Figure, lower panel). By Cox multivariable regression modeling, each 1% worsening in GLS was associated with a 23.6% increased risk-of-death after adjustment for clinical and imaging risk factors (HR=1.236 per %; p&lt;0.001). Addition of GLS in this model resulted in significant-improvement in the global-chi-square (67 to 168; p&lt;0.0001) and Harrel's C-statistic (0.716 to 0.825; p&lt;0.0001). Conclusions CMR feature-tracking derived GLS is a powerful independent predictor of mortality in patients with preserved ejection fraction, incremental to common clinical and imaging risk factors.

4937Global longitudinal strain by feature tracking predicts adverse remodeling in ST-elevation myocardial infarction incremental to

Abstract Objectives To evaluate the independent and incremental value of left ventricular (LV) strain assessed by cardiac magnetic resonance feature tracking (CMR-FT) for prediction of adverse LV remodeling following ST-elevation myocardial infarction (STEMI). Background The role of LV myocardial strain by CMR-FT for prediction of adverse remodeling after STEMI in comparison to LV ejection fraction and infarct severity is unclear. Methods STEMI patients treated with primary percutaneous coronary intervention within 24 hours after symptom onset were enrolled. CMR core laboratory analysis was performed to assess LV ejection fraction, infarct pathology and LV myocardial strain. The primary endpoint was adverse remodeling defined as ≥20% increase in LV end-diastolic volume from baseline to 4 months. Results From the 232 patients included, 38 (16.4%) reached the primary endpoint. Global longitudinal strain (GLS), global radial strain, and global circumferential strain were all predictive of adverse remodeling (p&lt;0.01 for all), but among strain values only GLS was an independent predictor of adverse remodeling (hazard ratio: 1.36 [1.03–1.78]; p=0.028) after adjustment for strain parameters, ejection fraction and CMR markers of infarct severity. A GLS &gt;-14% was associated with a 4-fold increase in risk for LV remodeling (hazard ratio: 4.16 [1.56–11.13]; p=0.005). Addition of GLS to a baseline model comprising ejection fraction, infarct size and microvascular obstruction resulted in net reclassification improvement of 0.26 ([0.13–0.38]; p&lt;0.001) and integrated discrimination improvement of 0.02 ([0.01–0.03]; p=0.006). Conclusions In STEMI survivors, determination of GLS using CMR-FT provides important prognostic information for the development of adverse remodeling that is incremental to LV ejection fraction and CMR markers of infarct severity.

Low Cardiac Output Syndrome After Adult Cardiac Surgery: Predictive Value of Peak Systolic Global Longitudinal Strain.

Peak systolic global longitudinal strain (GLS) is increasingly used to quantify left ventricular systolic function. The primary objective of this study was to assess whether GLS obtained during intraoperative transesophageal echocardiogram, performed before cardiopulmonary bypass, improves the prediction of postoperative low cardiac output syndrome (LCOS) after adult cardiac surgery. GLS from 275 patients undergoing on-pump cardiac surgery was calculated retrospectively using two-dimensional- speckle tracking echocardiography (aCMQ module from Qlab software version 10.5, Philips Medical, Brussels, Belgium). LCOS was defined as the need for inotropic or mechanical circulatory support for >24 hours postoperatively. Patient and procedure characteristics associated with LCOS at the univariable level (P ≤ .05) were entered into a forward stepwise logistic regression to create a first predictive model. A second model was created by adding GLS. The 2 models were compared using the likelihood-ratio test, the area under the receiver operating characteristic (ROC) curve, and the integrated discrimination index. The optimal cutoff value of GLS associated with LCOS was determined by maximizing the Youden index of the ROC curve. Secondary outcomes included time until complete weaning from inotropes, discharge from the intensive care unit and from the hospital, and 30-day mortality. GLS was significantly associated with LCOS (P < .001) at the univariable level. Predictors of LCOS retained in the first model were cardiopulmonary bypass duration, decreased left ventricular ejection fraction, mitral valve surgery, and New York Heart Association functional class III or IV. Adding the GLS value improved the prediction of LCOS (P = .02). However, the area under the ROC curve did not differ between the 2 models (0.83; 95% confidence interval [CI], 0.77-0.99 vs 0.84; 95% CI, 0.79-0.90; P = .15). The integrated discrimination index associated with addition of GLS was 0.02 (P = .046), meaning that the difference in predicted risk between patients with and without LCOS increased by 2% after adding GLS. A GLS cutoff value of -17% (95% CI, -18.8% to -15.3%) was found to best identify LCOS. After adjusting for covariates included in model 1, a lower GLS value was significantly associated with a lower cumulative probability of weaning from inotropes postoperatively (hazard ratio, 0.90; 95% CI, 0.82-0.97; P = .01). No association was found between GLS and other secondary outcome measures. GLS is an independent predictor of LCOS after on-pump cardiac surgery. Its incremental value over other established risk factors for postoperative LCOS is, however, limited.

Feature-Tracking Global Longitudinal Strain Predicts Death in a Multicenter Population of Patients With Ischemic and Nonischemic Dilated Cardiomyopathy Incremental to Ejection Fraction and Late Gadolinium Enhancement

ObjectivesThe aim of this study was to evaluate the prognostic value of cardiac magnetic resonance (CMR) feature-tracking–derived global longitudinal strain (GLS) in a large multicenter population of patients with ischemic and nonischemic dilated cardiomyopathy. BackgroundDirect assessment of myocardial fiber deformation with GLS using echocardiography or CMR feature tracking has shown promise in providing prognostic information incremental to ejection fraction (EF) in single-center studies. Given the growing use of CMR for assessing persons with left ventricular (LV) dysfunction, we hypothesized that feature-tracking–derived GLS may provide independent prognostic information in a multicenter population of patients with ischemic and nonischemic dilated cardiomyopathy. MethodsConsecutive patients at 4 U.S. medical centers undergoing CMR with EF <50% and ischemic or nonischemic dilated cardiomyopathy were included in this study. Feature-tracking GLS was calculated from 3 long-axis cine-views. The primary endpoint was all-cause death. Cox proportional hazards regression modeling was used to examine the association between GLS and death. Incremental prognostic value of GLS was assessed in nested models. ResultsOf the 1,012 patients in this study, 133 died during median follow-up of 4.4 years. By Kaplan-Meier analysis, the risk of death increased significantly with worsening GLS tertiles (log-rank p < 0.0001). Each 1% worsening in GLS was associated with an 89.1% increased risk of death after adjustment for clinical and imaging risk factors including EF and late gadolinium enhancement (LGE) (hazard ratio [HR]:1.891 per %; p < 0.001). Addition of GLS in this model resulted in significant improvement in the C-statistic (0.628 to 0.867; p < 0.0001). Continuous net reclassification improvement (NRI) was 1.148 (95% confidence interval: 0.996 to 1.318). GLS was independently associated with death after adjustment for clinical and imaging risk factors (including EF and late gadolinium enhancement) in both ischemic (HR: 1.942 per %; p < 0.001) and nonischemic dilated cardiomyopathy subgroups (HR: 2.101 per %; p < 0.001). ConclusionsCMR feature-tracking–derived GLS is a powerful independent predictor of mortality in a multicenter population of patients with ischemic or nonischemic dilated cardiomyopathy, incremental to common clinical and CMR risk factors including EF and LGE.

Correction: Prognostic power of global 2D strain according to left ventricular ejection fraction in patients with ST elevation myocardial infarction.

[This corrects the article DOI: 10.1371/journal.pone.0174160.].

Left ventricular dyssynergy and dispersion as determinant factors of fatal ventricular arrhythmias in patients with mildly reduced ejection fraction.

Current guidelines recommend implantation of prophylactic implantable cardioverter-defibrillators (ICD) in patients with left ventricular (LV) ejection fraction (EF) <35%. We explored the prognostic factors of fatal ventricular arrhythmias for heart failure (HF) patients with LVEF ≥35%. We retrospectively studied 72 patients with LVEF of 52 ± 12% (all ≥35%) who had undergone ICD implantation. Heterogeneity of LV regional myocardial contraction was defined as standard deviation of peak strain (dyssynergy index) and time-to-peak strain (dispersion index) from 18 LV segments determined by speckle tracking. Fatal ventricular arrhythmias with appropriate ICD therapy occurred in 34 patients (47%) during a median follow-up of 17 months. Receiver operating characteristic curve analysis identified dispersion index ≥101 ms and dyssynergy index ≥6.1% as predictors of fatal ventricular arrhythmias (P = 0.004 and P = 0.0001, respectively). In addition, the combination of dispersion index ≥101 ms and dyssynergy index ≥6.1% was the most predictive of fatal ventricular arrhythmias with a sensitivity of 77%, specificity of 79%, and area under the curve of 0.795 (P < 0.0001). A sequential Cox model based on clinical and conventional echocardiographic variables including age, gender, HF aetiology, and LVEF (χ(2) = 4.8) was improved, but not statistically significant (χ(2) = 4.9; P = 0.82), by addition of global longitudinal strain, whereas improvement by the addition of the dispersion index (χ(2) = 8.9; P = 0.04) and further improvement by the addition of the dyssynergy index (χ(2) = 20.2; P < 0.005). Combined assessment of LV dyssynergy and dispersion can enhance predictive capability for fatal ventricular arrhythmias in patients with LVEF ≥35% and may have potential for better management of such patients.

Impact of Flow and Left Ventricular Strain on Outcome of Patients With Preserved Left Ventricular Ejection Fraction and Low Gradient Severe Aortic Stenosis Undergoing Aortic Valve Replacement

The prognostic implications of flow, assessed by stroke volume index (SVi), and left ventricular (LV) global longitudinal strain on survival of patients with low-gradient severe aortic stenosis (AS) and preserved LV ejection fraction are debated. The aim of this study was to evaluate the impact of flow and LV global longitudinal strain on survival in these patients treated with aortic valve replacement (AVR). Patients with low-gradient severe AS with preserved LV ejection fraction treated with AVR (n= 134, mean age 76 ± 10years, 50% men) were included in the present study. Aortic valve hemodynamics and LV function were assessed with 2-dimensional, Doppler and speckle-tracking echocardiography before AVR. Patients were dichotomized on the basis of low (SVi ≤35ml/m(2)) or normal (SVi >35ml/m(2)) flow and impaired (>-15%) or more preserved (≤-15%) global longitudinal strain. The end point was all-cause mortality. During a median follow-up period of 1.8years (interquartile range 0.5 to 3) after AVR, 26 patients (19.4%) died. Survival was better for patients with SVi >35ml/m(2) or global longitudinal strain ≤-15% compared with those with SVi ≤35ml/m(2) or global longitudinal strain >-15% (log-rank p= 0.01). Atrial fibrillation (hazard ratio 5.40, 95% confidence interval 1.81 to 16.07, p= 0.002) and chronic kidney disease (hazard ratio 3.67, 95% confidence interval 1.49 to 9.06, p= 0.005) were the clinical variables independently associated with all-cause mortality. The addition of global longitudinal strain (chi-square= 19.87, p= 0.029, C-statistic= 0.74) or SVi (chi-square= 29.62, p <0.001, C-statistic= 0.80) to a baseline model including atrial fibrillation and chronic kidney disease (chi-square= 14.52, C-statistic= 0.68) improved risk stratification of these patients. In conclusion, flow and LV global longitudinal strain are independently associated with survival after AVR in patients with low-gradient severe AS with preserved LV ejection fraction.

IMPACT OF FLOW AND LEFT VENTRICULAR SYSTOLIC FUNCTION ON OUTCOME OF PATIENTS WITH PRESERVED LEFT VENTRICULAR EJECTION FRACTION AND LOW GRADIENT SEVERE AORTIC VALVE STENOSIS UNDERGOING AORTIC VALVE REPLACEMENT

The prognostic implications of flow, assessed by stroke volume index (SVi), and left ventricular (LV) global longitudinal strain on survival of patients with low-gradient severe aortic stenosis (AS) and preserved LV ejection fraction are debated. The aim of this study was to evaluate the impact of flow and LV global longitudinal strain on survival in these patients treated with aortic valve replacement (AVR). Patients with low-gradient severe AS with preserved LV ejection fraction treated with AVR (n [ 134, mean age 76 – 10 years, 50% men) were included in the present study. Aortic valve hemodynamics and LV function were assessed with 2-dimensional, Doppler and speckle-tracking echocardiography before AVR. Patients were dichotomized on the basis of low (SVi £35 ml/m 2 ) or normal (SVi >35 ml/m 2 ) flow and impaired (>L15%) or more preserved (£L15%) global longitudinal strain. The end point was all-cause mortality. During a median follow-up period of 1.8 years (interquartile range 0.5 to 3) after AVR, 26 patients (19.4%) died. Survival was better for patients with SVi >35 ml/m 2 or global longitudinal strain £L15% compared with those with SVi £35 ml/m 2 or global longitudinal strain >L15% (log-rank p [ 0.01). Atrial fibrillation (hazard ratio 5.40, 95% confidence interval 1.81 to 16.07, p [ 0.002) and chronic kidney disease (hazard ratio 3.67, 95% confidence interval 1.49 to 9.06, p [ 0.005) were the clinical variables independently associated with all-cause mortality. The addition of global longitudinal strain (chi-square [ 19.87, p [ 0.029, C-statistic [ 0.74) or SVi (chi-square [ 29.62, p <0.001, C-statistic [0.80) to a baseline model including atrial fibrillation and chronic kidney disease (chi-square [ 14.52, C-statistic [ 0.68) improved risk stratification of these patients. In conclusion, flowandLVglobal longitudinalstrainareindependently associatedwith survival after AVR in patients with low-gradient severe AS with preserved LV ejection fraction. 2014 Elsevier Inc. All rights reserved. (Am J Cardiol 2014;114:1875e1881)

The association between left ventricular global longitudinal strain, renal impairment and all-cause mortality

Left ventricular (LV) systolic dysfunction is an important predictor of cardiovascular death. Global longitudinal strain (GLS) is a widely available echocardiographic technique proven to be more sensitive than conventional ejection fraction (EF) in detecting subtle changes in LV function. However, the prognostic value of GLS in patients with chronic kidney disease (CKD) is unknown. We studied 447 patients from a single center who were stratified according to estimated glomerular filtration rate (eGFR). GLS was calculated using two-dimensional speckle tracking and EF was measured using Simpson's biplane. Cox proportional hazard model was used to identify independent predictors of survival and measures of discrimination and reclassification were used to assess the predictive value of GLS. Multivariable regression models were used to evaluate clinical and laboratory factors associated with GLS. The mean EF was 58 ± 11% and GLS was -16.6 ± 4.2%. eGFR correlated negatively with GLS (r = -0.14, P = 0.004). Factors that were independently associated with GLS include gender, previous myocardial infarction, eGFR and phosphate (R(2) = 0.16, P < 0.001). Sixty-four patients died in a follow-up of 5.2 ± 1.4 years. GLS remained a significant predictor of all-cause mortality [hazard ratio (HR) 1.08, 95% confidence interval (CI) 1.01-1.15] following adjustment for age, diabetes mellitus, hypertension, eGFR and left ventricular mass index (LVMI). The strength of association between demographic data, eGFR, LVMI and mortality increased following addition of GLS [c-statistic 0.68 (95% CI 0.61-0.74) to 0.71 (95% CI 0.64-0.77), P = 0.04]. Addition of GLS also demonstrated a 21% net reclassification improvement in risk prediction for all-cause mortality over clinical factors. GLS is an important predictor of all-cause mortality in CKD patients. Traditional and non-traditional risk factors such as phosphate are important determinants of GLS. Strain assessment in CKD patients may provide greater cardiovascular risk stratification.

Longitudinal Strain is Superior to Circumferential Strain in the Detection of Myocardial Ischaemia by Speckle Tracking during Dobutamine Stress Echocardiography

Background: Cardiovascular (CVS) death is the leading cause of mortality in patients with end stage chronic kidney disease (CKD). We wished to investigate the incremental value of contemporary measures of echocardiographic left ventricular (LV) assessment over standard baseline demographic features. Methods: We followed 183 patients (57.4% male, 61.2% dialysis) with stage 4/5 kidney disease for a mean of 7.8± 4.4 years. Forty-six (25%)patients diedof aCVScause within this time. Simpson’s ejection fraction (EF), global longitudinal strain (GLS) and radial strain (RS) were calculated. Nested Cox regression models were constructed to assess the predictive value of baseline variables and measures of LV myocardial mechanics for prediction of survival. Results: Mean EF was 44.6± 10.7%, GLS was −13.7± 4.1%, and RS 29.5± 18.3%. Receipt of a renal transplant (n= 70, 38.3%) was by far the strongest predictor of CVS outcome (hazard ratio HR=0.07; p< 0.01) and was not included in subsequent models. Other baseline predictors of CVS outcome (model χ2 = 45.5) were male gender (hazard ratio HR=2.48; p< 0.01), history of previous cardiac event (HR=3.2; p< 0.01), and knownperipheral arterial disease (HR=3.75; p< 0.01). The addition of GLS (HR=0.66; p< 0.05) and RS (HR=0.71; p< 0.05), but not EF, to the baseline model resulted in a significant increase in the predictive power of the model (model χ2 = 51.3 for GLS, 49.6 for RS, both p< 0.05). Conclusions: Baseline global longitudinal and radial strain is significant long term predictors of CVS outcome in patients with end stage CKD whereas EF is not. Incremental value is added to powerful baseline predictors of CVS outcome.