Mechanical Dyssynchrony Parameters Research Articles

Traditional Criteria of Mechanical and Electrical Dyssynchrony as a Predictor of Super-Response in Patients with Cardiac Resynchronization Therapy

Aim: To evaluate clinical and morpho-functional predictors of super-response to cardiac resynchronization therapy (CRT) in patients with heart failure and reduced ejection fraction (HFrEF) in the short-term period after implantation.Material and Methods. The study enrolled 86 patients (88.4% men, 54.0 ± 8.9 years mean age, New York Heart Association (NYHA) class II–IV). Patients were examined at baseline and in dynamics (mean follow-up was 10.6 ± 3.6 months). According to the change in left ventricular (LV) end-systolic volume (ESV) patients were divided into two groups: Group I (n = 19) with a decrease in LV ESV ≥ 30% (super-responders (SR) and Group II (n = 67) – decrease in LV ESV < 30% (non-super-responders (non-SR). Parameters of mechanical dyssynchrony (MD) were assessed in the two groups including LV pre-ejection period, interventricular mechanical delay (IVMD), intraventricular delay (IVD).Results. At baseline, traditional parameters of MD were higher in SR: LV pre-ejection period (156.8 ± 35.4 ms vs 135.0 ± 35.6 ms; p = 0.021) and IVMD (73.0 [43.0; 108.0] ms vs 47.0 [19.5; 70.0] ms; p = 0.017). Logistic regression results showed that female gender (HR 7.048; 95% CI 1.496–33.206; p = 0.014) and QRS width (HR 1.017; 95% CI 1.000–1.034; p = 0.048) had an independent association with super-response.Conclusion. In patients with HFrEF, more severe mechanical and electrical dyssynchrony is associated with super-response to CRT in a short-term follow-up period.

Cardiac magnetic resonance imaging in patients with left bundle branch block: Patterns of dyssynchrony and implications for late gadolinium enhancement imaging.

Left bundle branch block (LBBB) is a ventricular conduction delay with high prevalence. Aim of our study is to identify possible recurring patterns of artefacts in late gadolinium enhancement (LGE) imaging in patients with LBBB who undergo cardiac magnetic resonance imaging (MRI) and to define parameters of mechanical dyssynchrony associated with artefacts in LGE images. Fifty-five patients with LBBB and 62 controls were retrospectively included. Inversion time (TI) scout and LGE images were reviewed for artefacts. Dyssynchrony was identified using cardiac MRI by determining left ventricular systolic dyssynchrony indices (global, septal segments, and free wall segments) derived from strain analysis and features of mechanical dyssynchrony (apical rocking and septal flash). Thirty-seven patients (67%) with LBBB exhibited inhomogeneous myocardial nulling in TI scout images. Among them 25 (68%) patients also showed recurring artefact patterns in the septum or free wall on LGE images and artefacts also persisted in 18 (72%) of those cases when utilising phase sensitive inversion recovery. Only the systolic dyssynchrony index of septal segments allowed differentiation of patient subgroups (artefact/no artefact) and healthy controls (given as median, median ± interquartile range); LBBB with artefact: 10.44% (0.44-20.44%); LBBB without artefact: 6.82% (-2.18-15.83%); controls: 4.38% (1.38-7.38%); p < 0.05 with an area under the curve of 0.863 (81% sensitivity, 89% specificity). Septal flash and apical rocking were more frequent in the LBBB with artefact group than in the LBBB without artefact group (70 and 62% versus 33 and 17%; p < 0.05). Patients with LBBB show recurring artefact patterns in LGE imaging. Use of strain analysis and evaluation of mechanical dyssynchrony may predict the occurrence of such artefacts already during the examination and counteract misinterpretation.

Impact of diabetes mellitus in non-ischemic dilated cardiomyopathy: focus on diastolic dysfunction

Abstract Introduction In patients with diabetes mellitus (DM), the presence of myocardial dysfunction in the absence of coronary artery disease, valvular disease and other conventional cardiovascular risk factors has been defined as diabetic cardiomyopathy. Left ventricle concentric hypertrophy and myocardial fibrosis are the structural hallmarks that lead to overt diastolic dysfunction. The impact of DM in imaging features and clinical outcomes of patients with non-ischaemic dilated cardiomyopathy (DCM) has not been completely elucidated yet. Purpose We aim to describe advance imaging and clinical characteristics of DCM's patients with DM, and its potential impact on cardiac morphology and function in comparison to non-diabetic patients. Methods From 2014 to 2021, all patients with DCM were prospectively evaluated in our tertiary care hospital. All patients underwent a transthoracic echocardiogram and 165 patients underwent a 1.5 Tesla scanner cardiac magnetic resonance (CMR) as part of the diagnostic workup. Left ventricle ejection fraction (LVEF), mechanical dyssynchrony, and diastolic function were analyzed according to current guidelines. Late gadolinium enhancement (LGE) was assessed visually and its extent was calculated as the number of affected myocardial segments. Heart failure (HF) hospitalizations, arrhythmic events and mortality were assessed during follow-up. Results The median age of our cohort (n=227) was 61.6 (14.7) years, 66% were male, and DM was present in 57 patients (25.1%). Mean follow-up was 37.6 (33.9) months. Diabetic patients were significantly older, more frequently male, and with more comorbidity. Left bundle branch block was more frequent in patients with DM. The use of SGLT2 inhibitors was higher in diabetic patients (47.4% vs 21.1%; p&amp;lt;0.05). No significant differences were observed regarding other guideline-recommended HF drugs. With regard to imaging features, no significant differences were found in LVEF and global longitudinal strain between the two groups. There was a trend toward a higher left ventricle mass index measured by CMR in diabetic patients (p=0.364). Parameters of mechanical dyssynchrony and diastolic dysfunction were worse in diabetic patients (Table 1). High-risk LGE pattern (defined as the presence of epicardial, transmural or septal plus free-wall LGE) was more frequently observed in the diabetes group (p&amp;lt;0.05). Finally, the diabetic group had a higher incidence of HF hospitalization (45.61% vs 22%, p&amp;lt;0.001) and all-cause mortality (24.6% vs 11.8%, p&amp;lt;0.05), as shown in Figure 1. There was also a trend toward a higher cardiovascular mortality (12.3% vs 6.5%, p=0.164) in this group. Conclusion DM confers a high-risk profile to DCM patients, explained by extracardiac (more comorbidities) and cardiac (more diastolic dysfunction and high-risk LGE pattern) reasons. These patients may benefit from a close monitoring, and new therapies should be developed to improve their prognosis. Funding Acknowledgement Type of funding sources: None.

Strain-based discoordination imaging during exercise in heart failure with reduced ejection fraction: Feasibility and reproducibility

PurposeVarious parameters of mechanical dyssynchrony have been proposed to improve patient selection criteria for cardiac resynchronization therapy, but sensitivity and specificity are lacking. However, echocardiographic parameters are consistently investigated at rest, whereas heart failure (HF) symptoms predominately manifest during submaximal exertion. Although strain-based predictors of response are promising, feasibility and reproducibility during exercise has yet to be demonstrated.MethodsSpeckle-tracking echocardiography was performed in patients with HF at two separate visits. Echocardiography was performed at rest, during various exercise intensity levels, and during recovery from exercise. Systolic rebound stretch of the septum (SRSsept), systolic shortening, and septal discoordination index (SDI) were calculated.ResultsEchocardiography was feasible in about 70–80% of all examinations performed during exercise. Of these acquired views, 84% of the cine-loops were suitable for analysis of strain-based mechanical dyssynchrony. Test–retest variability and intra- and inter-operator reproducibility at 30% and 60% of the ventilatory threshold (VT) were about 2.5%. SDI improved in the majority of patients at 30% and 60% of the VT, with moderate to good agreement between both intensity levels.ConclusionAlthough various challenges remain, exercise echocardiography with strain analysis appears to be feasible in the majority of patients with dyssynchronous heart failure. Inter- and intra-observer agreement of SRSsept and SDI up to 60% of the VT were comparable to resting values. During exercise, the extent of SDI was variable, suggesting a heterogeneous response to exercise. Further research is warranted to establish its clinical significance.

Echocardiographic assessment of mechanical dyssynchrony: are the new parameters better?

Abstract Funding Acknowledgements Type of funding sources: None. Introduction - The high cost and important non-response rate are preventing optimal use of cardiac resynchronization therapy (CRT). Assessing mechanical dyssynchrony on echocardiography in candidates for CRT could remove these barriers by improving patient selection. In 2008 the PROSPECT study compared several old parameters of dyssynchrony in search of a reproducible parameter capable of better predicting response to CRT. Unfortunately, the results were disappointing and the assessment of dyssynchrony became discredited. Promising new parameters have been developed but a comparison with the old parameters is currently missing. Purpose - To compare the old and new parameters of mechanical dyssynchrony for (1) their effect on response to CRT as additional selection criteria, (2) predicting favourable long-term outcome after CRT and (3) their reproducibility. Methods - 146 CRT patients were analysed retrospectively in a multicentre setting. Mechanical dyssynchrony was assessed using three old parameters: septal-to-posterior wall motion delay (SPWMD), left ventricular filling time/cardiac cycle ratio (LVFT/RR), and intraventricular mechanical delay (IVMD); and three new parameters: systolic stretch index (SSI), myocardial work index (MWI), and visual presence of septal flash or apical rocking (SFoAR). Response to CRT was defined as a ≥15% decrease in LV end-systolic volume 1 year after CRT. For each parameter patients were categorized using previously published cut-offs as ‘eligible’ or ‘non-eligible’. The ‘non-eligible’ were considered untreated. Results were compared to the guidelines (Fig. 1). The hazard ratio (HR) for cardiac death within 5 years after implantation was computed for all patients (Fig. 2), and intra- and interrater agreement was determined. Results - 73% (n= 107) of patients showed response to CRT. The old parameters maintained less than 75% of the original responders. SFoAR preserved the highest proportion of responders (93%), while reducing the number of non-responders by 39% (Fig. 1). The prediction of cardiac death was significant for SFoAR (HR = 0.29; 95% CI: 0.12-0.74; P = 0.009) and IVMD (HR = 0.32; 95% CI: 0.13-0.79; P = 0.014) (Fig. 2). Intra- and interrater agreement was best for SFoAR (κ = 0.89; 95% CI: 0.67-1.0 and κ = 0.78; 95% CI: 0.50-1.0 respectively). Interrater agreement was poor for all old parameters (κ &amp;lt; 0.6). Conclusion - The new parameters for dyssynchrony are performing better. The visual presence of apical rocking or septal flash provided the most responders to CRT, predicted favourable long-term outcome and was highly reproducible. Our results show that future research should focus on the new parameters. Abstract Figure. Abstract Figure.

Evaluation of Cardiac Mechanical Dyssynchrony in Heart Failure Patients Using Current Echo-Doppler Modalities.

Current guidelines indicate electrical dyssynchrony as the major criteria for selecting patients for cardiac resynchronization therapy, and 25-35% of patients exhibit unfavorable responses to cardiac resynchronization therapy (CRT). We aimed to evaluate different cardiac mechanical dyssynchrony parameters in heart failure patients using current echo-Doppler modalities and we analyzed their association with electrical dyssynchrony. The study included 120 heart failure with reduced ejection fraction (HFrEF) who underwent assessments for left ventricular mechanical dyssynchrony (LVMD) and interventricular mechanical dyssynchrony (IVMD). Patients were classified according to QRS duration: group I with QRS < 120 ms, group II with QRS 120-149 ms, and group III with QRS ≥ 150 ms. Group III had significantly higher IVMD, LVMD indices, TS-SD speckle-tracking echocardiography (STE) 12 segments (standard deviation of time to peak longitudinal strain speckle tracking echocardiography in 12 LV-segments), and LVMD score compared with group I and group II. Group II and group III were classified according to QRS morphology into left bundle branch block (LBBB) and non-LBBB subgroups. LVMD score, TS-SD 12 TDI, and TS-SD 12 STE had good correlations with QRS duration. HFrEF patients with wide QRS duration (> 150 ms) had more evident LVMD compared with patients with narrow or intermediate QRS. Those patients with intermediate QRS duration (120-150 ms) had substantial LVMD assessed by both TDI and 2D STE, regardless of QRS morphology. Subsequently, we suggest that LVMD indices might be employed as additive criteria to predict CRT response in that patient subgroup. Electrical and mechanical dyssynchrony were strongly correlated in HFrEF patients.

Relationship between left bundle branch block mechanical patterns and super-response to cardiac resynchronization therapy in patients with congestive heart failure

Abstract Funding Acknowledgements Type of funding sources: None. Background Left bundle branch block (LBBB) assessed by electrocardiography (ECG) is used in current clinical guidelines for patient selection to cardiac resynchronisation therapy (CRT). But percentage of non-responders among patients with congestive heart failure is high. Super-response (SR) to CRT was not enough described in clinical guidelines. We hypothesized that mechanical patterns of LBBB and parameters of mechanical dyssynchrony could be used as predictors of SR to CRT. Aim To assess a relationship of LBBB patterns defined by ECG and echocardiography with SR to CRT. Materials and methods 60 patients (mean age 54.5 ± 10.4 years) were examined at baseline and during follow-up: 10.6 ± 3.6 months. Patients were divided into groups: I group (n = 31) with decrease of left ventricular end-systolic volume (ESV) ≥30% (super-responders) and II group (n = 29) - decrease of LV ESV &amp;lt;30% (non-super-responders). Three strain-markers of LBBB assessed by Tissue Doppler Imaging (TDI) and Speckle Tracking Echocardiography (STE) were used: (1) early contraction of basal or midventricular segment in the septal wall and early stretching of basal or midventricular segment in the lateral wall (yellow arrows); (2) the early peak contraction of the septal wall occurred in the first 70% of the systolic ejection phase (blue arrow); (3) the early stretching wall that showed peak contraction after aortic valve closure (red arrows). The classic LBBB pattern was defined if all three strain-markers were present. The heterogeneous LBBB pattern was defined if two from three strain-markers were present. Results At baseline groups did not differ in main clinical characteristics, including QRS width and LBBB assessed by ECG. Mechanical abnormalities were found only in group I: SF (32.3% vs 0.0%; p = 0.001) and apical rocking (19.4% vs 0.0%; p = 0.024), as well as classic LBBB mechanical pattern (20.8% vs 0.0%; p = 0.05). The complex of heterogeneous LBBB mechanical pattern (HR 7.512; 95% CI 1.434 – 39.632; р=0.025), interventricular mechanical delay (HR 1.037; 95% CI 1.005 – 1.071; р=0.017) and longitudinal strain of interventricular septum mid segment (HR 0.726; 95% CI 0.540 – 0.977; р=0.035) had an independent relationship with SR. According to the ROC analysis the sensitivity and specificity of model in the prediction of SR were 77.3% and 91.3% (AUC = 0.862; p &amp;lt; 0.001). Conclusion SR is associated with both LBBB mechanical patterns assessed by STE and TDI. LBBB defined by ECG did not have significant association with SR to CRT. Abstract Figure.

Comparison of left ventricular mechanical dyssynchrony parameters between exercise and adenosine triphosphate stress tests using gated single-photon emission computed tomography myocardial perfusion imaging.

Left ventricular mechanical dyssynchrony (LVMD) can be induced after stress test. However, no studies have compared the influence of different stress‑inducing methods on LVMD parameters. The aim of the study was to determine whether there is a difference between exercise and adenosine triphosphate (ATP) stress tests in terms of changes in LVMD parameters assessed using gated single‑photon emission computed tomography myocardial perfusion imaging (GSPECT MPI). A total of190 patients who underwent 99mTc ‑sestamibi GSPECT MPI were consecutively enrolled. Treadmill exercise and ATP stress tests were performed in 95 patients each. Normal myocardial perfusion was defined as the summed stress score (SSS) ≤3 and summed rest score (SRS) ≤3, myocardial ischemia as SSS >3 and SRS ≤3, and myocardial infarction as SSS >3 and SRS >3. Parameters of LVMD, including phase standard deviation (PSD), phase bandwidth (PBW), skewness, and kurtosis were compared. Subtraction was made between values during stress and rest phases to acquire ∆PSD, ∆PBW, ∆skewness, and ∆kurtosis Results: There were no differences in LVMD parameters between the exercise and ATP groups. The same results were obtained in the normal perfusion, ischemia, and infarction subgroups. Furthermore, no differences were observed in ∆PSD (median [interquartile range, IQR], 0.25 [-2.3 to 3.1] vs 0.42 (-1.7 to 3.1]; P = 0.73), ∆PBW (median [IQR], 1 [-7 to 11] vs 1 [-6 to 11]; P = 0.95), ∆skewness (mean [SD], -0.06 [0.63] vs 0 [0.81]; P = 0.53), and ∆kurtosis (median [IQR], -0.47 [-4.2 to 4.3] vs -0.42 [-4.8 to 5.2]; P = 0.73) between the exercise and ATP stress‑inducing methods. There are no differences between the exercise and ATP stress tests in terms of changes in LVMD parameters. Thus, the 2 methods can be used alternatively.

Effect of data conserving respiratory motion compensation on left ventricular functional parameters assessed in gated myocardial perfusion SPECT

BackgroundRespiratory motion compromises image quality in myocardial perfusion (MP) single-photon emission computed tomography (SPECT) imaging and may affect analysis of left ventricular (LV) functional parameters, including phase analysis-quantified mechanical dyssynchrony parameters. In this paper, we investigate the performance of two algorithms, respiratory blur modeling (RBM) and joint motion-compensated (JMC) ordered-subsets expectation maximization (OSEM), and the effects of motion compensation on cardiac-gated MP-SPECT studies.MethodsImage acquisitions were carried out with a dual-detector SPECT/CT system in list-mode format. A cardiac phantom was imaged as stationary and under respiratory motion. The images were reconstructed with OSEM, RBM-OSEM, and JMC-OSEM algorithms, and compared in terms of mean squared error (MSE). Subsequently, MP-SPECT data of 19 patients were binned into dual-gated (respiratory and cardiac gating) projection images. The images of the patients were analyzed with Quantitative Gated SPECT (QGS) 2012 program (Cedars-Sinai Medical Center, USA). The parameters of interest were LV volumes, ejection fraction, wall motion, wall thickening, phase analysis, and perfusion parameters.ResultsIn phantom experiment, compared to the stationary OSEM reconstruction, the MSE values for OSEM, RBM-OSEM, and JMC-OSEM were 8.5406·10−5,2.7190·10−5, and 2.0795·10−5, respectively. In the analysis of LV function, use of JMC had a small but statistically significant (p < 0.05) effect on several parameters: it increased LV volumes and standard deviation of phase angle histogram, and it decreased ejection fraction, global wall motion, and lateral, septal, and apical perfusion.ConclusionsCompared to standard OSEM algorithm, RBM-OSEM and JMC-OSEM both improve image quality under motion. Motion compensation has a minor effect on LV functional parameters.

Quantitative mechanical dyssynchrony in dilated cardiomyopathy measured by deformable registration algorithm.

To investigate the diagnostic value and reproducibility of deformable registration algorithm (DRA)-derived mechanical dyssynchrony parameters in dilated cardiomyopathy (DCM) patients. The present study included 80 DCM patients (40 with normal QRS duration (NQRS-DCM); 40 with left bundle branch block (LBBB-DCM)) and 20 healthy volunteers. The balanced steady-state free-precession (bSSFP) cine images were acquired using a 3.0T scanner. Mechanical dyssynchrony parameters were calculated based on DRA-derived segmental strain, including uniformity ratio estimate (URE) and standard derivation of time-to-peak (T2Psd) parameters in circumferential, radial, and longitudinal orientations. DCM patients showed significant mechanical dyssynchrony reflected by both URE and T2Psd parameters compared with controls. Among DCM patients, LBBB-DCM showed decreased CURE (0.78 ± 0.21 vs. 0.93 ± 0.05, p< 0.001) and RURE (0.69 ± 0.14 vs. 0.83 ± 0.15, p= 0.001), and increased T2Psd-Ecc (median with interquartile range, 94.1 (54.4-123.2) ms vs. 63.7 (44.9-80.4) ms, p= 0.003) and T2Psd-Err (91.1 (61.1-103.2) ms vs. 62.3 (46.3-104.5) ms, p= 0.041) compared with NQRS-DCM patients. CURE showed a strong correlation with QRS duration (r= - 0.54, p< 0.001), with maximum AUC (0.791) to differentiate LBBB-DCM from NQRS-DCM patients. Improved intra- and inter-observer reproducibility was found using URE indices (coefficient of variation (CoV), 1.20-3.17%) than T2Psd parameters (CoV, 15.28-41.18%). The DRA-based CURE showed significant correlation with QRS duration and the highest discriminatory value between LBBB-DCM and NQRS-DCM patients. URE indices showed greater reproducibility compared with T2Psd parameters for assessing myocardial dyssynchrony in DCM patients. • The strain analyses based on DRA suggested that DCM patients have varying degrees of mechanical dyssynchrony and there is a significant difference from normal controls. • CURE showed the strongest correlation with QRS duration and was the best parameter for differentiating DCM patients with normal QRS duration from patients with LBBB, and with normal controls. • URE indices showed improved reproducibility compared with T2Psd parameters in all three orientations (circumferential, radial, and longitudinal).

Right Ventricular Mechanical Dyssynchrony in Hypoplastic Left Heart Syndrome: Correlation with Systolic Function and QRS Duration.

The single right ventricle (RV) in hypoplastic left heart syndrome (HLHS) often develops systolic dysfunction with time and this affects prognosis. Mechanical dyssynchrony has been reported in HLHS but has not consistently correlated with systolic function or electrical dyssynchrony. The aims of this study were to assess the relationship between RV mechanical dyssynchrony, RV systolic function, and QRS duration on surface electrocardiography. We hypothesized that surface QRS duration would not be an adequate indicator of mechanical dyssynchrony compared with dyssynchrony parameters. Retrospective analysis of echocardiograms of patients with HLHS divided into preserved vs reduced RV function. We measured two RV function parameters: (1) fractional area change (FAC) and (2) global longitudinal strain (RVGLS). We measured two dyssynchrony parameters: (1) the standard deviation of the time to peak strain for 9 segments (tPS-9) and (2) time difference between the earliest and latest time to peak strain (RV dyssynchrony index or RVDI) bothcorrected for R-R interval. We also measured the QRS duration from surface EKG. Mechanical dyssynchrony parameters were compared to both RV systolic function and to QRS duration. 41 patients with HLHS were identified: 21 had preserved function and 20 had reduced function defined by a FAC < 35%. The reduced function group had a significantly lower mean FAC and RVGLS. RVDI was higher in the dysfunction group and had a modest correlation with FAC (r = 0.48) and RVGLS (r = 0.57). tPS-9 was longer in the dysfunction group and had a modest correlation with FAC (r = 0.45) and RVGLS (r = 0.57). QRS duration was longer in the dysfunction group and had a modest correlation with FAC (r = 0.56) and RVGLS (r = 0.56). The weakest correlations were between QRS duration and tPS-9 (r = 0.32) and QRS duration and RVDI (r = 0.10). RV dysfunction measured by FAC was associated with mechanical dyssynchrony measured by increased RVDI and tPS-9. QRS duration was longer in the group with dysfunction but did not correlate with directly measured mechanical dyssynchrony. This may have potential implications for cardiac resynchronization therapy in univentricular patients as assessed by mechanical dyssynchrony parameters rather than QRS duration alone.

Echocardiographic markers of dyssynchrony as predictors of super-response to cardiac resynchronisation therapy \u2013 a pilot study

BackgroundSome patients with congestive heart failure have greater improvement of cardiac remodelling after cardiac resynchronisation therapy (CRT) and they are identified as super-responders (SRs). It remains unclear if echocardiographic markers of dyssynchrony could accuratelly predict super-response to CRT. The aim of this study is to evaluate potential echocardiographic predictors associated with super-response to CRT.MethodsFifthy nine CRT patients (mean age 52.9 ± 9.0 years, 88% men) with congestive heart failure (54% ischaemic and 46% non-ischaemic aetiology) II-IV NYHA functional class were enrolled. To assess mechanical dyssynchrony we evaluated interventricular mechanical delay, the maximum delay between peak systolic velocities of the septal and posterior walls of left ventricle, duration of left ventricular pre-ejection period (LVPEP), left ventricular and interventricular dyssynchrony by tissue Doppler imaging and systolic dyssynchrony index by 3D echocardiography. After six months the patients were assessed for response and classified as SRs (reduction in left ventricular end-systolic volume (LVESV) ≥30%, n = 20) and non-SRs (reduction in LVESV < 30%, n = 39) and baseline data were analyzed to identify the predictors.ResultsBoth groups demonstrated significant improvement in NYHA functional class, increase in left ventricular ejection fraction and reduction in LVESV. All parameters of mechanical dyssynchrony at baseline were significantly higher in SR group. Multiple logistic regression analysis showed that LVPEP (HR 1.031; 95% CI 1.007–1.055; p = 0.011) was an independent predictor for CRT super-response. In ROC curve analysis LVPEP with a cut-off value of 147 ms demonstrated 73.7% sensitivity and 75% specificity (AUC = 0.753; p = 0.002) for the prediction of super-response to CRT.ConclusionGreater mechanical dyssynchrony is associated with super-response to CRT in patients with congestive heart failure. It is probable that an LVPEP > 147 ms can be used as independent predictor of super-response.

The Prognostic Value of Diastolic and Systolic Mechanical Left Ventricular Dyssynchrony Among Patients With Coronary Heart Disease

ObjectivesThe goal of this study was to examine whether diastolic dyssynchrony, measured by using gated single-photon emission computed tomography (GSPECT) myocardial perfusion imaging (MPI) in patients with coronary artery disease (CAD), is independently associated with adverse outcomes. BackgroundSystolic left ventricular dyssynchrony is known to be associated with worse clinical outcome in patients with CAD. MethodsThis study included patients who presented to Duke University for GSPECT MPI between 2003 and 2009. Patients had at least 1 major epicardial obstruction ≥50%. Dyssynchrony was assessed by using Emory Cardiac Toolbox software and compared with a control population without CAD. Abnormal degree of diastolic/systolic dyssynchrony was defined as values above 2 SDs above mean of mechanical dyssynchrony parameters. Using Cox proportional hazards modeling, the adjusted association between dyssynchrony and outcomes, including all-cause and cardiovascular death, was assessed. ResultsAmong 1,310 patients with a median age of 64 years (interquartile range: 55 to 72 years), 69.7% were male and 2.6% had left bundle branch block. Overall, 241 (18.4%) and 238 (18.2%) patients had significant systolic and diastolic mechanical dyssynchrony, respectively, and 211 (16.1%) had both. After a median follow-up of 7.1 years, 543 deaths occurred. At 5 years, the mortality estimate was 21.2% among patients with a normal degree of diastolic left ventricular mechanical dyssynchrony (LVMD) and 41.7% among those with an abnormal degree of LVMD (p < 0.001). When added to clinical comorbidities, electrical dyssynchrony, and systolic LVMD, diastolic dyssynchrony was incrementally associated with cardiovascular mortality (global chi-square statistic of 211.9 vs. 222.8; 2 degrees of freedom; p = 0.004). In a model that also includes left ventricular ejection fraction, the addition of diastolic dyssynchrony to systolic dyssynchrony maintained an incremental prognostic benefit (global chi-square statistic of 234.8 vs. 241.8; p = 0.030). Adjustment for baseline ischemia and scar burden did not change this relationship. ConclusionsSystolic and diastolic left ventricular dyssynchrony, as measured by using GSPECT MPI, were associated with adverse outcomes. Moreover, diastolic dyssynchrony appears to provide incremental predictive value to clinical history, electrical dyssynchrony, and left ventricular function.

Prediction of superresponse to cardiac resynchronisation therapy in patients with congestive heart failure

The aim.To evaluate clinical, morphological, functional features and mortality in patients with congestive heart failure (CHF) and super-response to cardiac resynchronization therapy (CRT), to assess presence and severity of mechanical dyssynchrony in patients with super-response and to find potential predictors of super-response to CRT.Methods.106 CRT patients (mean age 54.7 ± 9.9 years; 83% men) with CHF II–IV NYHA functional class were enrolled for the study. At baseline and each 6 months after implantation clinical, electrocardiographic and echocardiographic parameters, NT-proBNP level were evaluated. According to the best decrease of left ventricular endsystolic volume (LVESV) (mean follow-up period 34.9 ± 16.1 months) patients were classified as super-responders (SR) (n = 45; reduction in LVESV ≥30%) and non-SR (n = 61; reduction in LVESV &lt;30%).Results.At baseline groups were matched for main clinical characteristics. The proportion of patients with atrial fibrillation, width of the QRS complex, and the presence of left bundle-branch block were comparable between groups. Parameters of mechanical dyssynchrony were higher in SR: left ventricular pre-ejection period (LVPEP) (153.0 ± 35.9 ms vs 126.6 ± 35.1 ms; р = 0.005), interventricular mechanical delay (55.9 ± 30.8 ms vs 40.4 ± 29.9 ms; р = 0.049), systolic dyssynchrony index (9.6 ± 2.6% vs 7.2 ± 0.7%; р = 0.048). NT-proBNP level was lower in SR. SR demonstrated better dynamics of LVESV, LVEF. At baseline and in dynamics level of NT-proBNP was lower in SR. In both groups NT-proBNP decreased significantly, but reduction of NT-proBNP was more evident in SR. The survival rates were 100%in SR and 83.6% in non-SR (log rank test p = 0.002).According to multiple logistic regression analysis LVPEP (HR 1.025; 95% CI 1.006–1.044; p = 0.010) and baseline NT-proBNP level (HR 0.624; 95% CI 0.426–0.913; p = 0.015) were independent predictors for CRT super-response with sensitivity 71.9% and specificity 78.6%.Conclusion.In patients with CHF greater mechanical dyssynchrony and lower level of NT-proBNP are associated with CRT super-response. SR demonstrate better survival and better dynamics of functional parameters in long-term period. LVPEP and NT-proBNP level can be used as independent predictors of CRT super-response.

Biventricular dyssynchrony on cardiac magnetic resonance imaging and its correlation with myocardial deformation, ventricular function and objective exercise capacity in patients with repaired tetralogy of Fallot

BackgroundElectrical dyssynchrony and prolonged QRS duration are common in patients with repaired tetralogy of Fallot (ToF). It has been linked to increased risk of sudden cardiac death and right ventricular (RV) dysfunction. We investigated myocardial dyssynchrony using cardiac magnetic resonance imaging (CMR) and feature tracking analysis (FT) in this setting and compared it to myocardial deformation, conventional parameters of ventricular dysfunction and clinical parameters. Methods and resultsPatients underwent standardized CMR investigations as part of a nationwide study. We prospectively assessed myocardial deformation and analysed regional wall motion abnormalities of the RV and the left ventricle (LV) using CMR-FT. The main measure of dyssynchrony was the maximal time difference (wall motion delay) of the regional strain as a parameter of mechanical biventricular dyssynchrony. In addition, clinical parameters and measures of cardiopulmonary exercise capacity were available. Overall 345 patients were included. Parameters of biventricular wall motion delay correlated significantly with global FT-strain parameters (p < 0.0001 for all imaging planes assessed). Furthermore, we found a significant correlation between circumferential RV motion delay and QRS duration (p = 0.006). Higher LV and RV wall motion delay parameters were also associated with lower peak oxygen consumption (p < 0.05) and a worse LV and RV ejection fraction (p < 0.02). ConclusionsAssessment of mechanical dyssynchrony is feasible using CMR-FT in ToF patients. Parameters of mechanical dyssynchrony correlate with electrical dyssynchrony, biventricular function and objective exercise capacity in this setting. Due to the weak degree of correlation, however, the clinical significance of these findings remains to be clarified by further studies.

Comparison of strain parameters in dyssynchronous heart failure between speckle tracking echocardiography vendor systems

BackgroundAlthough mechanical dyssynchrony parameters derived by speckle tracking echocardiography (STE) may predict response to cardiac resynchronization therapy (CRT), comparability of parameters derived with different STE vendors is unknown.MethodsIn the MARC study, echocardiographic images of heart failure patients obtained before CRT implantation were prospectively analysed with vendor specific STE software (GE EchoPac and Philips QLAB) and vendor-independent software (TomTec 2DCPA). Response was defined as change in left ventricular (LV) end-systolic volume between examination before and six-months after CRT implantation. Basic longitudinal strain and mechanical dyssynchrony parameters (septal to lateral wall delay (SL-delay), septal systolic rebound stretch (SRSsept), and systolic stretch index (SSI)) were obtained from either separate septal and lateral walls, or total LV apical four chamber. Septal strain patterns were categorized in three types. The coefficient of variation and intra-class correlation coefficient (ICC) were analysed. Dyssynchrony parameters were associated with CRT response using univariate regression analysis and C-statistics.ResultsTwo-hundred eleven patients were analysed. GE-cohort (n = 123): age 68 years (interquartile range (IQR): 61–73), 67% male, QRS-duration 177 ms (IQR: 160–192), LV ejection fraction: 26 ± 7%. Philips-cohort (n = 88): age 67 years (IQR: 59–74), 60% male, QRS-duration: 179 ms (IQR: 166–193), LV ejection fraction: 27 ± 8. LV derived peak strain was comparable in the GE- (GE: -7.3 ± 3.1%, TomTec: −6.4 ± 2.8%, ICC: 0.723) and Philips-cohort (Philips: −7.7 ± 2.7%, TomTec: −7.7 ± 3.3%, ICC: 0.749). SL-delay showed low ICC values (GE vs. TomTec: 0.078 and Philips vs. TomTec: 0.025). ICC’s of SRSsept and SSI were higher but only weak (GE vs. TomTec: SRSsept: 0.470, SSI: 0.467) (Philips vs. QLAB: SRSsept: 0.419, SSI: 0.421). Comparability of septal strain patterns was low (Cohen’s kappa, GE vs. TomTec: 0.221 and Philips vs. TomTec: 0.279). Septal strain patterns, SRSsept and SSI were associated with changes in LV end-systolic volume for all vendors. SRSsept and SSI had relative varying C-statistic values (range: 0.530–0.705) and different cut-off values between vendors.ConclusionsAlthough global longitudinal strain analysis showed fair comparability, assessment of dyssynchrony parameters was vendor specific and not applicable outside the context of the implemented platform. While the standardization taskforce took an important step for global peak strain, further standardization of STE is still warranted.

Echocardiographic Prediction of Cardiac Resynchronization Therapy Response Requires Analysis of Both Mechanical Dyssynchrony and Right Ventricular Function: A Combined Analysis of Patient Data and Computer Simulations

Pronounced echocardiographically measured mechanical dyssynchrony is a positive predictor of response to cardiac resynchronization therapy (CRT), whereas right ventricular (RV) dysfunction is a negative predictor. The aim of this study was to investigate how RV dysfunction influences the association between mechanical dyssynchrony and left ventricular (LV) volumetric remodeling following CRT. One hundred twenty-two CRT candidates (mean LV ejection fraction, 19±6%; mean QRS width, 168±21msec) were prospectively enrolled and underwent echocardiography before and 6months after CRT. Volumetric remodeling was defined as percentage reduction in LV end-systolic volume. RV dysfunction was defined as RV fractional area change<35%. Mechanical dyssynchrony was assessed as time to peak strain between the septum and LV lateral wall, interventricular mechanical delay, and septal systolic rebound stretch. Simulations of heart failure with an LV conduction delay in the CircAdapt computer model were used to investigate how LV and RV myocardial contractility influence LV dyssynchrony and acute CRT response. In the entire patient cohort, higher baseline septal systolic rebound stretch, time to peak strain between the septum and LV lateral wall, and interventricular mechanical delay were all associated with LV volumetric remodeling in univariate analysis (R=0.599, R=0.421, and R=0.410, respectively, P<.01 for all). The association between septal systolic rebound stretch and LV volumetric remodeling was even stronger in patients without RV dysfunction (R=0.648, P<.01). However, none of the mechanical dyssynchrony parameters were associated with LV remodeling in the RV dysfunction subgroup. The computer simulations showed that low RV contractility reduced CRT response but hardly affected mechanical dyssynchrony. In contrast, LV contractility changes had congruent effects on mechanical dyssynchrony and CRT response. Mechanical dyssynchrony parameters do not reflect the negative impact of reduced RV contractility on CRT response. Echocardiographic prediction of CRT response should therefore include parameters of mechanical dyssynchrony and RV function.

Late best response to cardiac resynchronization therapy is associated with better survival of patients with congestive heart failure

AIM: The aim was to evaluate clinical, morphological, functional features and mortality in patients with congestive heart failure (CHF) and different time of the best response to cardiac resynchronization therapy (CRT). MATERIALS AND METHODS: 122 patients (82.8% men) with NYHA functional class III-IV (mean age 54.8 ± 9.6 years) were enrolled. At baseline, 1, 3 months and each 6 months after implantation we evaluated clinical and echocardiographic parameters. In 28 patients the best decrease of left ventricular end-systolic volume (LVESV) was achieved up to 3 months (1.1 ± 0.9 months, I group–early response) and in 94 patients–after 3 months (22.6 ± 14.9 months, II group–late response). RESULTS: At baseline groups did not differ in main clinical characteristics, the proportion of atrial fibrillation, the presence of left bundle-branch block (LBBB), width of the QRS complex and parameters of mechanical dyssynchrony. Level of left ventricular ejection fraction (LVEF) and left ventricular volumes were comparable between groups. In the II group responders (decrease in LVESV ≥ 15%) were identified more frequently (90.4% vs. 60.7%; p=0.001), all patients with decrease of LVESV ≥ 30% (super responders) had late response. During follow-up period (33.2 ± 16.7 months) increase in LVEF and decrease in LVESV were more evident in patients with late response. In Kaplan-Meier analysis mortality in II group was significantly lower (3.2% vs 28.6%; p=0.001). Cox regression showed that LVESV (HR 1.012; 95% CI 1.004–1.021; P=0.005) and the time of response (HR 0.131; 95% CI 0.032– 0.530; P=0.004) were associated with long-term mortality. CONCLUSION: Patients with early response to CRT show significantly lower improvement in LVEF and LVESV compared to patients with late CRT response. Super respone to CRT in associated with late functional improvement. Early response and greater LVESV are associated with higher mortality rate.

Abstract 13241: Additive Predictive Value of Strain Rate Dispersion Index for Responses to Cardiac Resynchronization Therapy: Substudy From the START Study

Background: Response to cardiac resynchronization therapy (CRT) depends not only on the degree of mechanical dyssynchrony but on that of discoordination, which could associate with insufficient predictive value of the parameters of mechanical dyssynchrony for the response especially in patients with moderately prolonged QRS duration and/or ischemic heart disease. We thus investigated an additive predictive value of strain rate dispersion index (SRDI), an index of the amount of discoordination, in patients undergoing CRT in a multicenter study. Methods: We studied 180 patients included in the Speckle Tracking Imaging for the Assessment of Cardiac Resynchronization Therapy (START) study, a prospective multicenter cohort study in Japan. Time from QRS to first peak of strain (T first ) was measured and its standard deviation (SD) was calculated as a dyssynchrony parameter for longitudinal (L-T first -SD) and circumferential (C-T first -SD) strains. SRDI was calculated as the average of segmental peak systolic strain rates minus peak global strain rate for longitudinal (L-SRDI) and circumferential (C-SRDI) strain rates. Responses to CRT was defined as a reduction of left ventricular end-systolic volume &gt;15% at 6 months after CRT. Results: One-hundred and nine (61%) patients were identified as responders. By Cox proportional hazards model, the addition of SRDIs resulted in a significant incremental improvement in the predictive value for the CRT response on LV end-diastolic volume (EDV) at baseline, QRS duration, ischemic etiology, and T first -SDs (Chi square: 41.0 vs 59.0, P&lt;0.001) in overall patients. Moreover, the same results were observed regardless of QRS duration or ischemic etiology ( Figure ). Conclusion: SRDI had an additive predictive value of responses to CRT even in patients with moderately prolonged QRS duration and those with ischemic heart disease.

16-68: Right ventricular dysfunction complicates prediction of response to cardiac resynchronization therapy by mechanical dyssynchrony parameters: combined clinical-modeling approach

16-68: Right ventricular dysfunction complicates prediction of response to cardiac resynchronization therapy by mechanical dyssynchrony parameters: combined clinical-modeling approach