Results of the Predictors of Response to CRT (PROSPECT) trial

Left ventricular strain for predicting the response to cardiac resynchronization therapy: two methods for one question

AIMS

Myocardial work (manually controlled software) and integral-derived longitudinal strain (automatic quantification of strain curves) are two promising tools to quantify dyssynchrony and potentially select the patients that are most likely to have a reverse remodelling due to cardiac resynchronization therapy (CRT). We sought to test and compare the value of these two methods in the prediction of CRT-response.

MATERIALS AND RESULTS

Two hundred and forty-three patients undergoing CRT-implantation from three European referral centres were considered. The characteristics from the six-segment of the four-chamber view were computed to obtain regional myocardial work and the automatically generated integrals of strain. The characteristics were studied in mono-parametric and multiparametric evaluations to predict CRT-induced 6-month reverse remodelling. For each characteristic, the performance to estimate the CRT response was determined with the receiver operating characteristic (ROC) curve and the difference between the performances was statistically evaluated. The best area under the curve (AUC) when only one characteristic used was obtained for a myocardial work (AUC = 0.73) and the ROC curve was significantly better than the others. The best AUC for the integrals was 0.63, and the ROC curve was not significantly greater than the others. However, with the best combination of works and integrals, the ROC curves were not significantly different and the AUCs were 0.77 and 0.72.

CONCLUSION

Myocardial work used in a mono-parametric estimation of the CRT-response has better performance compared to other methods. However, in a multiparametric application such as what could be done in a machine-learning approach, the two methods provide similar results.

The mechanism and prognosis of acute and late improvement in mitral regurgitation after cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) improves functional mitral regurgitation (MR); however, the mechanism and differences in acute and late improvement in MR are unclear. We aimed to evaluate the factors associated with the acute and late MR improvements and the prognosis of MR improvement after CRT. This retrospective study included 121 patients who underwent CRT implantation with full echocardiography assessment at baseline, 1 week, and 6 months after implantation. MR severity was classified into five grades (0: none to 4: severe). Two-dimensional speckle-tracking echocardiography with radial strain was used to assess dyssynchrony, and the time difference between the lateral and inferior segments at papillary muscle levels (TD_late-inf) was calculated. The MR improved 1 week and 6 months after CRT in 40 (33%) and 45 (37%) patients, respectively. On multivariate analyses, TD_late-inf (baseline-1 week) and SPWMD were independently associated with acute MR improvement. The %reduction in left ventricular end-systolic volume (LVESV) (baseline-6 months) and TD_late-inf (baseline-1 week) were independently correlated with late MR improvement. The patients with pre-MR grades 2-4 and improved MR after CRT showed significantly better prognosis in heart failure hospitalization. Cutoff values of ≥ 19.5 ms of the reduction of TD_late-inf and ≥ 30.8% of the %reduction of LVESV were significantly associated with the decrease in heart failure hospitalization. The improved interpapillary muscle activation time delay and volume reduction after CRT were associated with acute and late MR improvements. There may be different time course of recovery and distinct causes for late MR improvement.

Segment length in cine (SLICE) strain analysis: a practical approach to estimate potential benefit from cardiac resynchronization therapy

BACKGROUND

Segment length in cine (SLICE) strain analysis on standard cardiovascular magnetic resonance (CMR) cine images was recently validated against gold standard myocardial tagging. The present study aims to explore predictive value of SLICE for cardiac resynchronization therapy (CRT) response.

METHODS AND RESULTS

Fifty-seven patients with heart failure and left bundle branch block (LBBB) were prospectively enrolled in this multi-center study and underwent CMR examination before CRT implantation. Circumferential strains of the septal and lateral wall were measured by SLICE on short-axis cine images. In addition, timing and strain pattern parameters were assessed. After twelve months, CRT response was quantified by the echocardiographic change in left ventricular (LV) end-systolic volume (LVESV). In contrast to timing parameters, strain pattern parameters being systolic rebound stretch of the septum (SRSsep), systolic stretch index (SSIsep-lat), and internal stretch factor (ISFsep-lat) all correlated significantly with LVESV change (R - 0.56; R - 0.53; and R - 0.58, respectively). Of all strain parameters, end-systolic septal strain (ESSsep) showed strongest correlation with LVESV change (R - 0.63). Multivariable analysis showed ESSsep to be independently related to LVESV change together with age and QRSAREA.

CONCLUSION

The practicable SLICE strain technique may help the clinician to estimate potential benefit from CRT by analyzing standard CMR cine images without the need for commercial software. Of all strain parameters, end-systolic septal strain (ESSsep) demonstrates the strongest correlation with reverse remodeling after CRT. This parameter may be of special interest in patients with non-strict LBBB morphology for whom CRT benefit is doubted.

Importance of Systematic Right Ventricular Assessment in Cardiac Resynchronization Therapy Candidates: A Machine Learning Approach

BACKGROUND

Despite all having systolic heart failure and broad QRS intervals, patients screened for cardiac resynchronization therapy (CRT) are highly heterogeneous, and it remains extremely challenging to predict the impact of CRT devices on left ventricular function and outcomes. The aim of this study was to evaluate the relative impact of clinical, electrocardiographic, and echocardiographic data on the left ventricular remodeling and prognosis of CRT candidates by the application of machine learning approaches.

METHODS

One hundred ninety-three patients with systolic heart failure receiving CRT according to current recommendations were prospectively included in this multicenter study. A combination of the Boruta algorithm and random forest methods was used to identify features predicting both CRT volumetric response and prognosis. Model performance was tested using the area under the receiver operating characteristic curve. The k-medoid method was also applied to identify clusters of phenotypically similar patients.

RESULTS

From 28 clinical, electrocardiographic, and echocardiographic variables, 16 features were predictive of CRT response, and 11 features were predictive of prognosis. Among the predictors of CRT response, eight variables (50%) pertained to right ventricular size or function. Tricuspid annular plane systolic excursion was the main feature associated with prognosis. The selected features were associated with particularly good prediction of both CRT response (area under the curve, 0.81; 95% CI, 0.74-0.87) and outcomes (area under the curve, 0.84; 95% CI, 0.75-0.93). An unsupervised machine learning approach allowed the identification of two phenogroups of patients who differed significantly in clinical variables and parameters of biventricular size and right ventricular function. The two phenogroups had significantly different prognosis (hazard ratio, 4.70; 95% CI, 2.1-10.0; P < .0001; log-rank P < .0001).

CONCLUSIONS

Machine learning can reliably identify clinical and echocardiographic features associated with CRT response and prognosis. The evaluation of both right ventricular size and functional parameters has pivotal importance for the risk stratification of CRT candidates and should be systematically performed in patients undergoing CRT.

Blood flow patterns estimation in the left ventricle with low-rate 2D and 3D dynamic contrast-enhanced ultrasound

BACKGROUND AND OBJECTIVE

Left ventricle (LV) dysfunction always occurs at early heart-failure stages, producing variations in the LV flow patterns. Cardiac diagnostics may therefore benefit from flow-pattern analysis. Several visualization tools have been proposed that require ultrafast ultrasound acquisitions. However, ultrafast ultrasound is not standard in clinical scanners. Meanwhile techniques that can handle low frame rates are still lacking. As a result, the clinical translation of these techniques remains limited, especially for 3D acquisitions where the volume rates are intrinsically low.

METHODS

To overcome these limitations, we propose a novel technique for the estimation of LV blood velocity and relative-pressure fields from dynamic contrast-enhanced ultrasound (DCE-US) at low frame rates. Different from other methods, our method is based on the time-delays between time-intensity curves measured at neighbor pixels in the DCE-US loops. Using Navier-Stokes equation, we regularize the obtained velocity fields and derive relative-pressure estimates. Blood flow patterns were characterized with regard to their vorticity, relative-pressure changes (dp/dt) in the LV outflow tract, and viscous energy loss, as these reflect the ejection efficiency.

RESULTS

We evaluated the proposed method on 18 patients (9 responders and 9 non-responders) who underwent cardiac resynchronization therapy (CRT). After CRT, the responder group evidenced a significant (p<0.05) increase in vorticity and peak dp/dt, and a non-significant decrease in viscous energy loss. No significant difference was found in the non-responder group. Relative feature variation before and after CRT evidenced a significant difference (p<0.05) between responders and non-responders for vorticity and peak dp/dt. Finally, the method feasibility is also shown with 3D DCE-US.

CONCLUSIONS

Using the proposed method, adequate visualization and quantification of blood flow patterns are successfully enabled based on low-rate DCE-US of the LV, facilitating the clinical adoption of the method using standard ultrasound scanners. The clinical value of the method in the context of CRT is also shown.

Real-World Economic Burden Among Patients With And Without Heart Failure Worsening After Cardiac Resynchronization Therapy

INTRODUCTION

Although cardiac resynchronization therapy (CRT) has the potential to improve cardiac function in patients with heart failure (HF), a considerable portion of patients do not respond to therapy. This study assessed the economic burden among patients with and without HF worsening after receiving CRT in real-world practice.

METHODS

In this retrospective claims-based study using Optum's de-identified Clinformatics^® Data Mart Database (January 2007-December 2018), adults who received CRT were stratified into two cohorts based on whether they showed evidence of HF worsening within 180 days post-CRT implantation. Inverse probability of treatment weighting (IPTW) was used to adjust for confounding, accounting for demographics (e.g., age, sex), the Quan-Charlson Comorbidity Index, other clinical characteristics, healthcare resource utilization (HRU), and healthcare costs during the 180 days pre-CRT (baseline period). Annualized all-cause and congestive HF-related HRU and healthcare costs from payer and patient perspectives were assessed from day 181 post-CRT (follow-up period), and compared between cohorts using incidence rate ratios (IRRs) and cost ratios (CRs).

RESULTS

This study included 12,753 patients (n = 4785 with HF worsening; n = 7968 without). Mean age was 72 years and roughly two-thirds were male. Baseline characteristics were balanced between cohorts post-IPTW. During follow-up, patients with HF worsening had significantly greater annual all-cause inpatient [adjusted IRR (95% confidence interval) = 1.55 (1.44, 1.66), p < 0.001], outpatient [adjusted IRR = 1.46 (1.32, 1.61), p < 0.001], and emergency department [adjusted IRR = 1.31 (1.22, 1.41), p < 0.001] visits. Mean annual total per patient payer-paid amounts were significantly higher for patients with HF worsening versus without HF worsening [adjusted CR = 1.68 (1.56, 1.80), p < 0.001]. Annual patient-paid medical costs were also higher for patients with HF worsening [adjusted CR = 1.31 (1.25, 1.38), p < 0.001]. Results were similar for congestive HF-related HRU and costs.

CONCLUSIONS

The incremental economic burden among patients with HF worsening following CRT is substantial. Efforts aimed at CRT optimization may help reduce this burden.

Cardiovascular Imaging Applications in Clinical Management of Patients Treated with Cardiac Resynchronization Therapy

Cardiovascular imaging techniques, including echocardiography, nuclear cardiology, multi-slice computed tomography, and cardiac magnetic resonance, have wide applications in cardiac resynchronization therapy (CRT). Our aim was to provide an update of cardiovascular imaging applications before, during, and after implantation of a CRT device. Before CRT implantation, cardiovascular imaging techniques may integrate current clinical and electrocardiographic selection criteria in the identification of patients who may most likely benefit from CRT. Assessment of myocardial viability by ultrasound, nuclear cardiology, or cardiac magnetic resonance may guide optimal left ventricular (LV) lead positioning and help to predict LV function improvement by CRT. During implantation, echocardiographic techniques may guide in the identification of the best site of LV pacing. After CRT implantation, cardiovascular imaging plays an important role in the assessment of CRT response, which can be defined according to LV reverse remodeling, function and dyssynchrony indices. Furthermore, imaging techniques may be used for CRT programming optimization during follow-up, especially in patients who turn out to be non-responders. However, in the clinical settings, the use of proposed functional indices for different imaging techniques is still debated, due to their suboptimal feasibility and reproducibility. Moreover, identifying CRT responders before implantation and turning non-responders into responders at follow-up remain challenging issues.

Characterization of non-response to cardiac resynchronization therapy by post-procedural computed tomography

INTRODUCTION

Causes of non-response to cardiac resynchronization therapy (CRT) include mechanical dyssynchrony, myocardial scar, and suboptimal left ventricular (LV) lead location. We aimed to assess the utility of Late Iodine Enhancement Computed Tomography (LIE-CT) with image subtraction in characterizing CRT non-response.

METHODS

CRT response was defined as a decrease in LV end-systolic volume > 15% at 6 months. LIE-CT was performed after 6 months, and analyzed global and segmental dyssynchrony, myocardial scar, coronary venous anatomy, and position of LV lead relative to scar and segment of latest mechanical contraction.

RESULTS

We evaluated 29 patients (age 71 ± 12 years; 72% men) including 18 (62%) responders. All metrics evaluating residual dyssynchrony such as wall motion index and wall thickness index were worse in non-responders. There was no difference in presence and extent of scar between responders and non-responders. However, in non-responders, the LV lead was more often over an akinetic/dyskinetic area (72% vs. 22%, p = .007), a fibrotic area (64% vs. 8%, p = .0007), an area with myocardial thickness < 6 mm (82% vs. 22%, p = .002), and less often concordant with the region of maximal wall thickness (9% vs. 72%, p = .001). Among the 11 non-responders, eight had at least another coronary venous branch visualized by CT, including three (27%) coursing over a potentially interesting myocardial area (free of scar, with normal wall motion, and with a myocardial thickness ≥6 mm).

CONCLUSION

LIE-CT with image subtraction allows a comprehensive characterization of patients after CRT and may provide clues for management of non-responders.

Phase analysis, a novel SPECT technique for left ventricular dyssynchrony: Are degrees and milliseconds interchangeable?

BACKGROUND

Phase analysis of gated single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy provides a measure of left ventricular dyssynchrony and may have applications for identifying patients suitable for cardiac resynchronisation therapy. Phase analysis is typically described in degrees of cardiac cycle, less intuitive to cardiologists familiar with ECGs. We assessed the relationship between time and degrees, to determine whether they are interchangeable.

METHODS AND RESULTS

399 patients underwent normal stress-only SPECT myocardial perfusion imaging using Technetium-99m-tetrofosmin. Data analysis used QGS software (Cedars Sinai) calculating bandwidth and standard deviation. Heart rate, age, gender, stress modality, and ejection fraction were analyzed for their relation to phase variables. 13 patients were excluded for conduction abnormalities including right and left bundle branch block and ventricular pacing. Heart rate was strongly correlated to bandwidth and standard deviation measured in time, but unrelated when measured in degrees. Although bandwidth measured by time and degrees were strongly correlated with each other this relationship was not perfect (correlation coefficient 0.87, P < .001). The addition of heart rate to the model explained most of the residual variation between the two. The results for standard deviation were similar.

CONCLUSION

In patients with normal myocardial perfusion and QRS duration bandwidth measured by degrees is not directly interchangeable with time in milliseconds. However most of the variation is explainable by heart rate, which predominantly affects measures of time rather than degrees. We would propose that although the values are less intuitive to cardiologists, normal ranges for phase measured in degrees are potentially more robust.

Optimized implementation of cardiac resynchronization therapy: a call for action for referral and optimization of care: A joint position statement from the Heart Failure Association (HFA), European Heart Rhythm Association (EHRA), and European Association of Cardiovascular Imaging (EACVI) of the European Society of Cardiology

Cardiac resynchronization therapy (CRT) is one of the most effective therapies for heart failure with reduced ejection fraction and leads to improved quality of life, reductions in heart failure hospitalization rates and all-cause mortality. Nevertheless, up to two-thirds of eligible patients are not referred for CRT. Furthermore, post-implantation follow-up is often fragmented and suboptimal, hampering the potential maximal treatment effect. This joint position statement from three European Society of Cardiology Associations, Heart Failure Association (HFA), European Heart Rhythm Association (EHRA) and European Association of Cardiovascular Imaging (EACVI), focuses on optimized implementation of CRT. We offer theoretical and practical strategies to achieve more comprehensive CRT referral and post-procedural care by focusing on four actionable domains: (i) overcoming CRT under-utilization, (ii) better understanding of pre-implant characteristics, (iii) abandoning the term 'non-response' and replacing this by the concept of disease modification, and (iv) implementing a dedicated post-implant CRT care pathway.

Usefulness of Hemodynamic Device-Based Optimization in Heterogeneous Patients Implanted with Cardiac Resynchronization Therapy Defibrillator

Optimization of the atrioventricular (AV) and interventricular (VV) timings of the CRT is the most supposed correctable variable to improve the rate of CRT responder. The aim of the present study has been to evaluate if there is a specific subgroup of patients who can actually benefit the most from a hemodynamic optimization of AV. This is a prospective, observational single-center study that enrolled consecutive patients with clinical indication for CRT; all patients were implanted with CRT-D devices with SonR technology, able to automatically adjust AV and VV delay on a weekly basis. Among 57 patients, 39 (69%) showed a LVESV reduction > 15%. The SonR was able to modify the pacing parameters, but an increase of left atrial diameter was associated to a reduced AV variability, suggesting that an impaired left atrial function could potentially reduce the ability of the SonR algorithm to adjust the correct timing of pacing. Graphical abstract Patients with respectively a high (A) and low (B) AV timing variability, among several parameters that could potentially influence the AV timing, only left atrial dimensions demonstrated a significant impact. In fact an increase of left atrial diameter was associated to a reduced AV variability, suggesting that an impaired left atrial function could potentially reduce the ability of the SonR algorithm to adjust the correct timing of pacing.

Clinical significance of left ventricular reverse remodeling after catheter ablation of atrial fibrillation in patients with left ventricular systolic dysfunction

BACKGROUND

Left ventricular (LV) reverse remodeling (LVRR) after catheter ablation of atrial fibrillation (AFCA) has not been fully described. This study investigated the predictors and clinical outcomes of LVRR after AFCA in patients with LV systolic dysfunction.

METHODS

Of 3319 consecutive patients who underwent first-time AFCA between January 2012 and October 2019, 376 with a baseline LV ejection fraction of <50% were retrospectively evaluated. They were subjected to 256-slice multidetector computed tomography (MDCT) scanning at baseline and 3 months after AFCA. The LVRR was defined as a decrease in the LV end-systolic volume of ≥15%.

RESULTS

The prevalence of LVRR was 83% (n = 306). Multivariate logistic regression analysis including age, body mass index, diabetic status, beta-blocker use, and LV diastolic diameter revealed that the predictors of LVRR were non-paroxysmal atrial fibrillation (AF) (odds ratio, 2.68; 95% confidence interval, 1.42-5.05; p = 0.002) and absence of apparent underlying structural heart disease (4.81; 2.31-10.0; p <0.001). The prevalence of LVRR differed depending on AF recurrence pattern prior to the post-MDCT [no episode vs. paroxysmal episode (lasting <7 days) vs. persistent episode (lasting ≥7 days), 84% vs. 81% vs. 63%, respectively, p = 0.023]. During a median follow-up of 32 months, the incidence of paroxysmal form of AF recurrence was similar, whereas persistent form of AF recurrence was less frequent in patients with LVRR (10.5% vs. 18.6%, p = 0.018). Heart failure hospitalizations (2.3% vs. 15.7%, p <0.001), cardiovascular deaths (0.7% vs. 4.3%, p = 0.015), and all-cause deaths (1.3% vs. 5.7%, p = 0.018) were similarly less frequent in those with LVRR.

CONCLUSIONS

LVRR after AFCA, which was predicted by non-paroxysmal AF without any apparent structural heart disease at baseline, was associated with persistent form of AF recurrence prior to the evaluation. LVRR was associated with favorable clinical outcomes.

Multimodality imaging in the diagnosis, risk stratification, and management of patients with dilated cardiomyopathies: an expert consensus document from the European Association of Cardiovascular Imaging

Dilated cardiomyopathy (DCM) is defined by the presence of left ventricular or biventricular dilatation and systolic dysfunction in the absence of abnormal loading conditions or coronary artery disease sufficient to explain these changes. This is a heterogeneous disease frequently having a genetic background. Imaging is important for the diagnosis, the prognostic assessment and for guiding therapy. A multimodality imaging approach provides a comprehensive evaluation of all the issues related to this disease. The present document aims to provide recommendations for the use of multimodality imaging according to the clinical question. Selection of one or another imaging technique should be based on the clinical condition and context. Techniques are presented with the aim to underscore what is 'clinically relevant' and what are the tools that 'can be used'. There remain some gaps in evidence on the impact of multimodality imaging on the management and the treatment of DCM patients where ongoing research is important.

Novel Non-Invasive Index for Prediction of Responders in Cardiac Resynchronization Therapy Using High-Resolution Magnetocardiography

BACKGROUND

Approximately one-third of patients with advanced heart failure (HF) do not respond to cardiac resynchronization therapy (CRT). We investigated whether the left ventricular (LV) conduction pattern on magnetocardiography (MCG) can predict CRT responders.

METHODS AND RESULTS

This retrospective study enrolled 56 patients with advanced HF (mean [±SD] LV ejection fraction [LVEF] 23±8%; QRS duration 145±19 ms) and MCG recorded before CRT. MCG-QRS current arrow maps were classified as multidirectional (MDC; n=28) or unidirectional (UDC; n=28) conduction based on a change of either ≥35° or <35°, respectively, in the direction of the maximal current arrow after the QRS peak. Baseline New York Heart Association functional class and LVEF were comparable between the 2 groups, but QRS duration was longer and the presence of complete left bundle branch block and LV dyssynchrony was higher in the UDC than MDC group. Six months after CRT, 30 patients were defined as responders, with significantly more in the UDC than MDC group (89% vs. 14%, respectively; P<0.001). Over a 5-year follow-up, Kaplan-Meyer analysis showed that adverse cardiac events (death or implantation of an LV assist device) were less frequently observed in the UDC than MDC group (6/28 vs. 15/28, respectively; P=0.027). Multivariate analysis revealed that UDC on MCG was the most significant predictor of CRT response (odds ratio 69.8; 95% confidence interval 13.14-669.32; P<0.001).

CONCLUSIONS

Preoperative non-invasive MCG may predict the CRT response and long-term outcome after CRT.

Prediction of response to cardiac resynchronization therapy using a multi-feature learning method

We hypothesized that a multiparametric evaluation, based on the combination of electrocardiographic and echocardiographic parameters, could enhance the appraisal of the likelihood of reverse remodeling and prognosis of favorable clinical evolution to improve the response of cardiac resynchronization therapy (CRT). Three hundred and twenty-three heart failure patients were retrospectively included in this multicenter study. 221 patients (68%) were responders, defined by a decrease in left ventricle end-systolic volume ≥15% at the 6-month follow-up. In addition, strain data coming from echocardiography were analyzed with custom-made signal processing methods. Integrals of regional longitudinal strain signals from the beginning of the cardiac cycle to strain peak and to the instant of aortic valve closure were analyzed. QRS duration, septal flash and different other features manually extracted were also included in the analysis. The random forest (RF) method was applied to analyze the relative feature importance, to select the most significant features and to build an ensemble classifier with the objective of predicting response to CRT. The set of most significant features was composed of Septal Flash, E, E/A, E/EA, QRS, left ventricular end-diastolic volume and eight features extracted from strain curves. A Monte Carlo cross-validation method with 100 runs was applied, using, in each run, different random sets of 80% of patients for training and 20% for testing. Results show a mean area under the curve (AUC) of 0.809 with a standard deviation of 0.05. A multiparametric approach using a combination of echo-based parameters of left ventricular dyssynchrony and QRS duration helped to improve the prediction of the response to cardiac resynchronization therapy.

Cardiac resynchronisation therapy in patients with left bundle branch block with residual conduction

Aim

To evaluate whether left bundle branch block with residual conduction (rLBBB) is associated with worse outcomes after cardiac resynchronisation therapy (CRT).

Methods

All consecutive CRT implants at our institution between 2006 and 2013 were identified from our local device registry. Pre- and post-implant patient specific data were extracted from clinical records.

Results

A total of 690 CRT implants were identified during the study period. Prior to CRT, 52.2% of patients had true left bundle branch block (LBBB), 19.1% a pacing-induced LBBB (pLBBB), 11.2% a rLBBB, 0.8% a right bundle branch block (RBBB), and 16.5% had a nonspecific intraventricular conduction delay (IVCD) electrocardiogram pattern. Mean age at implant was 67.5 years (standard deviation [SD] = 10.6), mean left ventricular ejection fraction (LV EF) was 25.7% (SD = 7.9%), and mean QRS duration was 158.4 ms (SD = 32 ms). After CRT, QRS duration was significantly reduced in the LBBB (p < 0.001), pLBBB (p < 0.001), rLBBB (p < 0.001), RBBB (p = 0.04), and IVCD groups (p = 0.03). LV EF significantly improved in the LBBB (p < 0.001), rLBBB (p = 0.002), and pLBBB (p < 0.001) groups, but the RBBB and IVCD groups showed no improvement. There was no significant difference in mortality between the LBBB and rLBBB groups. LV EF post-CRT, chronic kidney disease, hyperkalaemia, hypernatremia, and age at implant were significant predictors of mortality.

Conclusion

CRT in patients with rLBBB results in improved LV EF and similar mortality rates to CRT patients with complete LBBB. Predictors of mortality post-CRT include post-CRT LV EF, presence of CKD, hyperkalaemia, hypernatremia, and older age at implant.

Comprehensive plasma metabolites profiling reveals phosphatidylcholine species as potential predictors for cardiac resynchronization therapy response

Aims

This study aimed to identify the plasma metabolite fingerprint in patients with heart failure and to develop a prediction tool based on differential metabolites for predicting the response to cardiac resynchronization therapy (CRT).

Methods and results

We prospectively recruited 32 healthy individuals and 42 consecutive patients with HF who underwent CRT between January 2018 and January 2019. Peripheral venous blood samples, clinical data, and echocardiographic signatures were collected before CRT implantation. Liquid chromatography‐mass spectrometry was used to perform untargeted metabolites profiling for peripheral plasma under ESI+ and ESI− modes. After 6 month follow‐up, patients were categorized as CRT responders or non‐responders based on the alterations of echocardiographic characteristics. Compared with healthy individuals, patients with HF had distinct metabolomic profiles under both ESI+ and ESI− modes, featuring increased free fatty acids, carnitine, β‐hydroxybutyrate, and dysregulated lipids with heterogeneous alterations such as phosphatidylcholines (PCs) and sphingomyelins. Disparities of baseline metabolomics profile were observed between CRT responders and non‐responders under ESI+ mode but not under ESI− mode. Further metabolites analysis revealed that a group of 20 PCs metabolites under ESI+ mode were major contributors to the distinct profiles between the two groups. We utilized LASSO regression model and identified a panel of four PCs metabolites [including PC (20:0/18:4), PC (20:4/20:0), PC 40:4, and PC (20:4/18:0)] as major predictors for CRT response prediction. Among our whole population (n = 42), receive operating characteristics analysis revealed that the four PCs‐based model could nicely discriminate the CRT responders from non‐responders (area under the curve = 0.906) with a sensitivity of 83.3% and a specificity of 90.0%. Cross‐validation analysis also showed a satisfactory and robust performance of the model with the area under the curve of 0.910 in the training dataset and 0.880 in the testing dataset.

Conclusions

Patients with HF held significantly altered plasma metabolomics profile compared with the healthy individuals. Within the HF group, the non‐responders had a distinct plasma metabolomics profile in contrast to the responders to CRT, which was characterized by increased PCs species. A novel predictive model incorporating four PCs metabolites performed well in identifying CRT non‐responders. These four PCs might severe as potential biomarkers for predicting CRT response. Further validations are needed in multi‐centre studies with larger external cohorts.

Impact of non-cardiovascular comorbidities on the quality of life of patients with chronic heart failure: a scoping review

PURPOSE

To determine the impact of non-cardiovascular comorbidities on the health-related quality of life (HRQoL) of patients with chronic heart failure (CHF).

METHODS

A scoping review of the scientific literature published between 2009 and 2019 was carried out. Observational studies which assessed the HRQoL of patients with CHF using validated questionnaires and its association with non-cardiovascular comorbidities were included.

RESULTS

The search identified 1904 studies, of which 21 fulfilled the inclusion criteria to be included for analysis. HRQoL was measured through specific, generic, or both types of questionnaires in 72.2%, 16.7%, and 11.1% of the studies, respectively. The most common comorbidities studied were diabetes mellitus (12 studies), mental and behavioral disorders (8 studies), anemia and/or iron deficiency (7 studies), and respiratory diseases (6 studies). Across studies, 93 possible associations between non-cardiovascular comorbidities and HRQoL were tested, of which 21.5% regarded anemia or iron deficiency, 20.4% mental and behavioral disorders, 20.4% diabetes mellitus, and 14.0% respiratory diseases. Despite the large heterogeneity across studies, all 21 showed that the presence of a non-cardiovascular comorbidity had a negative impact on the HRQoL of patients with CHF. A statistically significant impact on worse HRQoL was found in 84.2% of associations between mental and behavioral disorders and HRQoL (patients with depression had up to 200% worse HRQoL than patients without depression); 73.7% of associations between diabetes mellitus and HRQoL (patients with diabetes mellitus had up to 21.8% worse HRQoL than patients without diabetes mellitus); 75% of associations between anemia and/or iron deficiency and HRQoL (patients with anemia and/or iron deficiency had up to 25.6% worse HRQoL than between patients without anemia and/or iron deficiency); and 61.5% of associations between respiratory diseases and HRQoL (patients with a respiratory disease had up to 21.3% worse HRQoL than patients without a respiratory disease).

CONCLUSION

The comprehensive management of patients with CHF should include the management of comorbidities which have been associated with a worse HRQoL, with special emphasis on anemia and iron deficiency, mental and behavioral disorders, diabetes mellitus, and respiratory diseases. An adequate control of these comorbidities may have a positive impact on the HRQoL of patients.

Imaging predictors of response to cardiac resynchronization therapy: left ventricular work asymmetry by echocardiography and septal viability by cardiac magnetic resonance

AIMS

Left ventricular (LV) failure in left bundle branch block is caused by loss of septal function and compensatory hyperfunction of the LV lateral wall (LW) which stimulates adverse remodelling. This study investigates if septal and LW function measured as myocardial work, alone and combined with assessment of septal viability, identifies responders to cardiac resynchronization therapy (CRT).

METHODS AND RESULTS

In a prospective multicentre study of 200 CRT recipients, myocardial work was measured by pressure-strain analysis and viability by cardiac magnetic resonance (CMR) imaging (n = 125). CRT response was defined as ≥15% reduction in LV end-systolic volume after 6 months. Before CRT, septal work was markedly lower than LW work (P < 0.0001), and the difference was largest in CRT responders (P < 0.001). Work difference between septum and LW predicted CRT response with area under the curve (AUC) 0.77 (95% CI: 0.70-0.84) and was feasible in 98% of patients. In patients undergoing CMR, combining work difference and septal viability significantly increased AUC to 0.88 (95% CI: 0.81-0.95). This was superior to the predictive power of QRS morphology, QRS duration and the echocardiographic parameters septal flash, apical rocking, and systolic stretch index. Accuracy was similar for the subgroup of patients with QRS 120-150 ms as for the entire study group. Both work difference alone and work difference combined with septal viability predicted long-term survival without heart transplantation with hazard ratio 0.36 (95% CI: 0.18-0.74) and 0.21 (95% CI: 0.072-0.61), respectively.

CONCLUSION

Assessment of myocardial work and septal viability identified CRT responders with high accuracy.

Reproducibility and repeatability of identifying the latest electrical activation during mapping of coronary sinus branches in CRT recipients

INTRODUCTION

Studies have shown an association between the outcome in cardiac resynchronization therapy (CRT) and longer interventricular delay at the site of the left ventricular (LV) lead. Targeted LV lead placement at the latest electrically activated segment increases LV function further as compared with standard treatment. We aimed to determine reproducibility and repeatability of identifying the latest electrically activated segment during mapping of all available coronary sinus (CS) branches in patients receiving CRT.

METHODS

We included 35 patients who underwent CRT implantation with protocolled mapping guided LV lead implantation aiming for the site of the latest electrical activation. Three different doctors experienced in electrophysiology and implantation of CRT devices independently measured time interval from the local bipolar right ventricular (RV) electrogram (EGM) to the local unipolar LV EGM at all mapped sites (RV-LV). The segment with the latest electrical activation was defined as the target segment (TS) and the CS tributary containing TS was defined as the target vein (TV). Weighted κ statistics with 95% confidence intervals were computed to assess intra- and interobserver agreement for TS and TV.

RESULTS

We mapped 258 segments within 131 veins. Weighted κ values for repeatability were 0.85 (0.81-0.89) for TS and 0.92 (0.89-0.93) for TV, and weighted κ values of interobserver agreement ranged from 0.70 (0.61-0.73) to 0.80 (0.76-0.83) for TS and 0.73 (0.64-0.78) to 0.86 (0.83-0.89) for TV among all three observers.

CONCLUSION

The reproducibility and repeatability of identifying the latest electrically activated segment during mapping of all available CS branches in patients receiving CRT range from good to very good.

Patient-specific heart simulation can identify non-responders to cardiac resynchronization therapy

To identify non-responders to cardiac resynchronization therapy (CRT), various biomarkers have been proposed, but these attempts have not been successful to date. We tested the clinical applicability of computer simulation of CRT for the identification of non-responders. We used the multi-scale heart simulator “UT-Heart,” which can reproduce the electrophysiology and mechanics of the heart based on a molecular model of the excitation–contraction mechanism. Patient-specific heart models were created for eight heart failure patients who were treated with CRT, based on the clinical data recorded before treatment. Using these heart models, bi-ventricular pacing simulations were performed at multiple pacing sites adopted in clinical practice. Improvement in pumping function measured by the relative change of maximum positive derivative of left ventricular pressure (%ΔdP/dt_max) was compared with the clinical outcome. The operators of the simulation were blinded to the clinical outcome. In six patients, the relative reduction in end-systolic volume exceeded 15% in the follow-up echocardiogram at 3 months (responders) and the remaining two patients were judged as non-responders. The simulated %ΔdP/dt_max at the best lead position could identify responders and non-responders successfully. With further refinement of the model, patient-specific simulation could be a useful tool for identifying non-responders to CRT.

Septal contraction predicts acute haemodynamic improvement and paced QRS width reduction in cardiac resynchronization therapy

AIMS

Three distinct septal contraction patterns typical for left bundle branch block may be assessed using echocardiography in heart failure patients scheduled for cardiac resynchronization therapy (CRT). The aim of this study was to explore the association between these septal contraction patterns and the acute haemodynamic and electrical response to biventricular pacing (BIVP) in patients undergoing CRT implantation.

METHODS AND RESULTS

Thirty-eight CRT candidates underwent speckle tracking echocardiography prior to device implantation. The patients were divided into two groups based on whether their septal contraction pattern was indicative of dyssynchrony (premature septal contraction followed by various amount of stretch) or not (normally timed septal contraction with minimal stretch). CRT implantation was performed under invasive left ventricular (LV) pressure monitoring and we defined acute CRT response as ≥10% increase in LV dP/dtmax. End-diastolic pressure (EDP) and QRS width served as a diastolic and electrical parameter, respectively. LV dP/dtmax improved under BIVP (737 ± 177 mmHg/s vs. 838 ± 199 mmHg/s, P < 0.001) and 26 patients (68%) were defined as acute CRT responders. Patients with premature septal contraction (n = 27) experienced acute improvement in systolic (ΔdP/dtmax: 18.3 ± 8.9%, P < 0.001), diastolic (ΔEDP: -30.6 ± 29.9%, P < 0.001) and electrical (ΔQRS width: -23.3 ± 13.2%, P < 0.001) parameters. No improvement under BIVP was observed in patients (n = 11) with normally timed septal contraction (ΔdP/dtmax: 4.0 ± 7.8%, P = 0.12; ΔEDP: -8.8 ± 38.4%, P = 0.47 and ΔQRS width: -0.9 ± 11.4%, P = 0.79).

CONCLUSION

Septal contraction patterns are an excellent predictor of acute CRT response. Only patients with premature septal contraction experienced acute systolic, diastolic, and electrical improvement under BIVP.

Tracking the motion of intracardiac structures aids the development of future leadless pacing systems

BACKGROUND

Leadless pacemakers preclude the need for permanent leads to pace endocardium. However, it is yet to be determined whether a leadless pacemaker of a similar design to those manufactured for the right ventricle (RV) fits within the left ventricle (LV), without interfering with intracardiac structures.

METHODS

Cardiac computed tomography scans were obtained from 30 patients indicated for cardiac resynchronisation therapy upgrade. The mitral valve annulus, chordae tendineae, papillary muscles and LV endocardial wall were marked in the end-diastolic frame. Intracardiac structures motions were tracked through the cardiac cycle. Two pacemaker designs similar to commercially manufactured leadless systems (Abbott's Nanostim LCP and Medtronic's Micra TPS) as well as theoretical designs with calculated optimal dimensions were evaluated. Pacemakers were virtually placed across the LV endocardial surface and collisions between them and intracardiac structures were detected throughout the cycle.

RESULTS

Probability maps of LV intracardiac structures collisions on a 16-segment AHA model indicated possible placement for the Nanostim LCP, Micra TPS, and theoretical designs. Thresholding these maps at a 20% chance of collision revealed only about 36% of the endocardial surface remained collision-free with the deployment of Micra TPS design. The same threshold left no collision-free surface in the case of the Nanostim LCP. To reach at least half of the LV endocardium, the volume of Micra TPS, which is the smaller design, needed to be decreased by 41%.

CONCLUSION

Due to the presence of intracardiac structures, placement of leadless pacemakers with dimensions similar to commercially manufactured RV systems would be limited to apical regions.

Multi-Modality Imaging in Dilated Cardiomyopathy: With a Focus on the Role of Cardiac Magnetic Resonance

Heart failure (HF) is recognized as a leading cause of morbidity and mortality worldwide. Dilated cardiomyopathy (DCM) is a common phenotype in patients presenting with HF. Timely diagnosis, appropriate identification of the underlying cause, individualized risk stratification, and prediction of clinical response to treatment have improved the prognosis of DCM over the last few decades. In this article, we reviewed the current evidence on available imaging techniques used for DCM patients. In this direction, we evaluated appropriate scenarios for the implementation of echocardiography, nuclear imaging, and cardiac computed tomography, and we focused on the primordial role that cardiac magnetic resonance (CMR) holds in the diagnosis, prognosis, and tailoring of therapeutic options in this population of special clinical interest. We explored the predictive value of CMR toward left ventricular reverse remodeling and prediction of sudden cardiac death, thus guiding the decisions for device therapy. Principles underpinning the use of state-of-the-art CMR techniques such as parametric mapping and feature-tracking strain analysis are also provided, along with expectations for the anticipated future advances in this field. We also attempted to correlate the evidence with clinical practice, with the intent to address questions on selecting the optimal imaging method for different indications and clinical needs. Overall, we recommend a comprehensive assessment of DCM patients at baseline and at follow-up intervals depending on the clinical status, with the addition of CMR as a second-line modality to other imaging techniques. We also provide an algorithm to guide the detailed imaging approach of the patient with DCM. We expect that future guidelines will upgrade their clinical recommendations for the utilization of CMR in DCM, which is expected to further improve the quality of care and the outcomes. This review provides an up-to-date perspective on the imaging of dilated cardiomyopathy patients and will be of clinical value to training doctors and physicians involved in the area of heart failure.

Increases in repolarization heterogeneity predict left ventricular systolic dysfunction and response to cardiac resynchronization therapy in patients with left bundle branch block

INTRODUCTION

This study aimed to investigate the association between T-wave morphology and impaired left ventricular ejection fraction (LVEF) in patients with complete left bundle branch block (cLBBB), and the predictive value of T-wave morphology for response to cardiac resynchronization therapy (CRT).

METHODS AND RESULTS

We enrolled 189 patients with cLBBB on electrocardiogram performed between January 2007 and December 2011 who underwent standard echocardiography. Repolarization parameters, including the QRS-to-T angle (TCRT), T-wave morphology dispersion (TMD), T-wave loop area (PL), and T-wave residuum (TWR), were reconstructed from digital standard 12-lead electrocardiograms by T-wave morphology analysis. CRT response was defined as ≥15% reduction in left ventricular end-systolic volume at 12 months after CRT implantation. The clinical outcome endpoint was a composite of heart failure hospitalization, heart transplantation, or death during follow up (mean, 5.8 years). On logistic regression, a higher heart rate, longer QRS duration, increased TMD, and larger TWR were all independently associated with LVEF < 40%. Among 40 patients who underwent CRT, those with a larger TMD (P = .007), larger PL (P = .025), and more negative TCRT (P = .015) had better response to CRT. A large TMD (P = .018) and large PL (P = .003) were also independent predictors of the clinical outcome endpoint.

CONCLUSIONS

Increases in repolarization heterogeneity in patients with cLBBB are associated with impaired LVEF. A large TMD and large PL may be useful as additional predictors of response to CRT, improving patient selection for CRT.

Left Ventricular End-Systolic Volume Is a Reliable Predictor of New-Onset Heart Failure with Preserved Left Ventricular Ejection Fraction

Background

Left ventricular (LV) ejection fraction (EF) and LV volumes were reported to have prognostic efficacy in cardiac diseases. In particular, the end-systolic volume index (LVESVI) has been featured as the most reliable prognostic indicator. However, such efficacy in patients with LVEF ≥ 50% has not been elucidated.

Methods

We screened the patients who received cardiac catheterization to evaluate coronary artery disease concomitantly with both left ventriculography and LV pressure recording using a catheter-tipped micromanometer and finally enrolled 355 patients with LVEF ≥ 50% and no history of heart failure (HF) after exclusion of the patients with severe coronary artery stenosis requiring early revascularization. Cardiovascular death or hospitalization for HF was defined as adverse events. The prognostic value of LVESVI was investigated using a Cox proportional hazards model.

Results

A univariable analysis demonstrated that age, log BNP level, tau, peak − dP/dt, LVEF, LV end-diastolic volume index (LVEDVI), and LVESVI were associated with adverse events. A correlation analysis revealed that LVESVI was significantly associated with log BNP level (r = 0.356, p < 0.001), +dP/dt (r = −0.324, p < 0.001), −dP/dt (r = 0.391, p < 0.001), and tau (r = 0.337, p < 0.001). Multivariable analysis with a stepwise procedure using the variables with statistical significance in the univariable analysis revealed that aging, an increase in BNP level, and enlargement of LVESVI were significant prognostic indicators (age: HR: 1.071, 95% CI: 1.009–1.137, p=0.024; log BNP : HR : 1.533, 95% CI: 1.090–2.156, p=0.014; LVESVI : HR : 1.051, 95% CI: 1.011–1.093, p=0.013, respectively). According to the receiver-operating characteristic curve analysis for adverse events, log BNP level of 3.23 pg/ml (BNP level: 25.3 pg/ml) and an LVESVI of 24.1 ml/m² were optimal cutoff values (BNP : AUC : 0.753, p < 0.001, LVESVI : AUC : 0.729, p < 0.001, respectively).

Conclusion

In patients with LVEF ≥ 50%, an increased LVESVI is related to the adverse events. LV contractile performance even in the range of preserved LVEF should be considered as a role of a prognostic indicator.

Significance of myeloperoxidase plasma levels as a predictor for cardiac resynchronization therapy response

Objectives

This study aimed to determine if changes in myeloperoxidase (MPO) levels correlate with response to cardiac resynchronization therapy (CRT) and the potential role of MPO as a predictor of response to CRT.

Background

CRT is a well-established treatment option in chronic heart failure (CHF) with 50–80% of patients benefiting. Inflammation and oxidative stress play a key role in CHF pathophysiology. Previous studies have demonstrated increased levels of MPO in CHF patients, but the correlation with CRT response remains incompletely understood.

Methods

Fifty-three patients underwent CRT implantation. During follow-up, patients were divided into two groups, responders and non-responders to CRT, based on improved physical capacity and NYHA classification. Levels of MPO and NT-pro-brain-natriuretic-peptide (NT-proBNP) were determined prior to implantation, 30 and 90 days after. Physical capacity, including a 6-min walking-test, NYHA class, and LVEF were evaluated at baseline and during follow-up.

Results

Thirty-four patients (64%) responded to CRT, showing improved physical capacity and LVEF. All responders revealed a significant decrease of MPO levels (503.8 ng/ml vs. 188.4 ng/ml; p < 0.001). Non-responding patients did not show any significant changes in clinical parameters or MPO levels (119.6 ng/ml vs. 134.3 ng/ml; p = 0.672) during follow-up. At baseline, physical capacity and NYHA class, as well as MPO levels differed significantly between both groups (p < 0.001). A ROC analysis identified an MPO cut-off value for response to CRT of 242 ng/ml with a sensitivity of 93.5% and specificity of 71.4%. There was a strong correlation between MPO and improvement of LVEF (Spearman’s rho: − 0.453; p = 0.005) and physical capacity (Spearman’s rho: − 0.335; p = 0.042).

Conclusions

Response to CRT and course of MPO levels correlate significantly. MPO levels differ between responders and non-responders prior to CRT, which may indicate an additional value of MPO as a predictor for CRT response. Further randomized studies are required to confirm our data in larger patient cohorts.

Intraoperative Epicardial Triventricular Pacing in a Pediatric Patient

Cardiac resynchronization therapy (CRT) is used as an adjunctive therapy in adults with advanced heart failure but remains less commonly applied in pediatric patients. Further, CRT is traditionally conducted via biventricular transvenous pacing from the right ventricle and coronary sinus to activate the left ventricle and improve electromechanical synchrony; however, triventricular pacing, in which a third ventricular lead is utilized to activate an additional ventricular location, has been shown to be a feasible therapeutic alternative to typical CRT in patients with advanced heart failure or nonresponders. Limited adult studies involving triventricular pacing have been performed to date but no pediatric data are available. Thus, we present the case of a 12-month-old patient with congenital complete heart block and subsequent pacemaker-induced cardiomyopathy in whom triventricular epicardial pacing was applied in an effort to increase the available knowledge.

[Echocardiographic assessment of myocardial function during His bundle and right ventricular pacing]

INTRODUCTION

In patients with pacemaker (PM) therapy, His bundle stimulation (HBS) may lead to a more synchronous activation of the left ventricle (LV) than conventional right ventricular stimulation (RVS). In this study, we investigated to which extent this effect can be objectified by means of contemporary echocardiographic functional imaging.

METHODS

In all, 15 RVS patients (6 women, mean age 76.6 ± 4.1 years) and 15 HBS patients (6 women, mean age 74.6 ± 3.7 years) underwent echocardiography with and without cardiac pacing. Besides LV end-diastolic volume (EDV), ejection fraction (EF), and global strain (GLS), we measured global and regional myocardial work and LV efficiency based on noninvasive pressure-strain loops.

RESULTS

In all HBS patients, optimization of PM settings resulted in immediate changes in myocardial function parameters. With pacing, RVS patients showed a higher decrease in EF and GLS than HBS patients. Global LV work and LV work efficiency decreased significantly only in RVS patients.

CONCLUSION

Changes in regional and global myocardial function can by proven and quantified by functional echocardiography. In patients under PM therapy, HBS shows functional advantages in comparison to conventional RVS.

Combination of Left Ventricular End-Diastolic Diameter and QRS Duration Strongly Predicts Good Response to and Prognosis of Cardiac Resynchronization Therapy

Background

Approximately 20–40% of recipients of cardiac resynchronization therapy (CRT) do not respond to it based on the current patient selection criteria. The purpose of this study was to identify baseline parameters that can predict CRT response and to evaluate the effect of those predictive parameters on long-term prognosis.

Methods

This was a retrospective, nonrandomized, noncontrolled cohort study. Patients who received CRT in our centre were divided into responders and nonresponders by the definition of CRT response (an increase in left ventricular ejection fraction (LVEF) of ≥5% and improvement of ≥1 New York Heart Association (NYHA) class from baseline to the 6-month follow-up).

Results

Of the 101 patients, 68 were responders and 33 were nonresponders. Left ventricular end-diastolic diameter (LVEDD; OR: 0.88, 95% CI: 0.81–0.95, P=0.001) and QRS duration (OR: 1.07, 95% CI: 1.04–1.10, P < 0.001) were independent predictors of CRT response. The combination of LVEDD and QRS duration was more valuable for predicting CRT response (AUC 0.836; 95% CI: 0.76–0.91; P < 0.001). Moreover, the combination of LVEDD ≤ 71 mm and QRS duration ≥ 170 ms had a low incidence of all-cause mortality, HF hospitalisation, and the composite endpoint. In addition, baseline LVEDD had a positive correlation with QRS duration (R=0.199, P=0.046). Responders to CRT had better LV reverse remodeling.

Conclusion

The combination of LVEDD and QRS duration provided more robust prediction of CRT response. Moreover, the combination of LVEDD ≤ 71 mm and QRS duration ≥ 170 ms was associated with a low incidence of all-cause mortality, HF hospitalisation, and the composite endpoint. Our results may be useful to provide individualized patient selection for CRT.

Validation of Three European Risk Scores to Predict Long-Term Outcomes for Patients Receiving Cardiac Resynchronization Therapy in an Asian Population

To validate externally and recalibrate three European risk scores for all-cause mortality and transplantation in patients receiving cardiac resynchronization therapy (CRT) in an Asian population. Data were collected at our institution between January 2010 and December 2017. The primary endpoints were all-cause mortality and heart transplantation. Of the 506 patients who were followed for 2 years, 104 reached the primary endpoint. The Kaplan-Meier event-free survival analysis, stratified according to the three scores, yielded significant results (log-rank test, all P < 0.05), with a good fit between the predicted and observed event rates (Hosmer-Lemeshow goodness-of-fit test, all P > 0.05). The ScREEN score yielded the best discriminatory power for the primary endpoints compared with the VALID-CRT and EAARN scores. ScREEN was the best predictor of all-cause mortality and heart transplantation. Risk scores based on different populations should be selected cautiously. Graphical Abstract.

Noninvasive cardiac output measurement based optimization in nonresponders of cardiac resynchronization therapy

BACKGROUND

Cardiac resynchronization therapy (CRT) is an important and effective therapy for end-stage heart failure (HF). Nonresponse to CRT is one of the main obstacles to its application in clinical practice. Herein, we investigated the utilization of the optimization technique using noninvasive cardiac output measurement (NICOM) based Mobil-O-Graph device that measures several circulation parameters noninvasively.

METHODS

Seventy-five CRT nonresponder HF patients with an implanted CRT device were included. Patients were randomized equally to 3 groups: NICOM, echocardiographic, and empirical optimization groups. After 3 months of optimization, changes in six minutes walk test (6-MWT), cardiac output (CO), left ventricular ejection fraction (LVEF), and end-systolic volume (LVESV) were measured. New York Heart Association (NYHA) class and hospitalization for HF were also determined.

RESULTS

There were no statistically significant differences among the three groups in terms of demographics, baseline characteristics. In the NICOM group, the 6-MWT, LVEF, CO, and LVESV measurements showed significant improvements compared to baseline values (P < .05). There was no significant improvement in 6-MWT, LVEF, CO, NYHA class, and LVESV in Echo and Empirical groups after 3 months (P > .05). 6-MWT, CO, LVESV percentages, and hospitalization for HF were significantly different between the groups (P < .05). In post hoc analyzes, the percentages of the change in 6-MWT, CO, LVESV, and hospitalization for HF were significantly higher in the NICOM group (P < .017).

CONCLUSIONS

This study suggests that Mobil-O-Graph device optimization according to CO measures does appear to have potential hemodynamic and clinical benefits in nonresponder CRT patients. Use of Mobil-O-Graph device as an option for optimization of CRT devices can be an attractive method of improving CRT outcomes.

Acute correction of electromechanical dyssynchrony and response to cardiac resynchronization therapy

Aims

Echocardiographic measures of dyssynchrony at baseline have not demonstrated a good ability to predict response to cardiac resynchronization therapy (CRT). The purpose of this study was to determine if the acute correction of electromechanical dyssynchrony, assessed by the change in simple pulsed‐Doppler measures, was related to CRT response at 6 months.

Methods and results

Echocardiography was performed at baseline and at pre‐discharge after CRT implantation. Intraventricular, interventricular, and atrioventricular dyssynchrony were evaluated by the left pre‐ejection interval (LPEI), the interventricular mechanical delay, and the ratio of left ventricular filling time to RR interval, respectivelxy. A patient was considered responder if he/she was alive without hospitalization for heart failure and had an absolute increase of left ventricular ejection fraction (LVEF) >5 points. Forty‐eight patients (mean age 67 ± 11 years, 73% male, mean LVEF 30 ± 5%) were included. CRT led to an acute correction of intraventricular and interventricular dyssynchrony but not to an acute correction of atrioventricular dyssynchrony. There were 31 (65%) responders at 6 months. Two factors were independently associated with CRT response in multivariate analysis: ischemic cardiomyopathy (odds ratio 0.19, 95% confidence interval 0.04–0.87; P= 0.032) and delta LPEI (odds ratio 1.03 per 1 ms decrease, 95% confidence interval 1.01–1.05; P = 0.007). By receiver operating characteristic analysis, the optimal cut‐off value of delta LPEI was −16 ms. The proportion of responders in patients without ischemic cardiomyopathy and with a delta LPEI greater than −16 ms was 85%.

Conclusions

Acute correction of intraventricular electromechanical dyssynchrony evaluated by the LPEI predicted CRT response at 6 months.

Left ventricular wall thickness assessed by cardiac computed tomography and cardiac resynchronization therapy outcomes

AIMS

Up to 30% of selected heart failure patients do not benefit clinically from cardiac resynchronization therapy (CRT). Left ventricular (LV) wall thickness (WT) analysed using computed tomography (CT) has rarely been evaluated in response to CRT and mitral regurgitation (MR) improvement. We examined the association of LVWT and the ability to reverse LV remodelling and MR improvement after CRT.

METHODS AND RESULTS

Fifty-four patients scheduled for CRT underwent pre-procedural CT. Reduced LVWT was defined as WT <6 mm and quantified as a percentage of total LV area. Endpoints were 6-month clinical and echocardiographic response to CRT [New York Heart Association (NYHA) class, LV ejection fraction (LVEF), LV end-diastolic volume (LVEDV), and LV end-systolic volume (LVESV)], MR improvement and 2-year major adverse cardiac events (MACE). Patients were divided into three groups according to the percentage of LVWT <6 mm area: ≤20%, 20-50%, and ≥50%. At 6 months, 75%, 71%, and 42% of the patients experienced NYHA improvement in the ≤20%, 20-50%, and ≥50% group, respectively. Additionally, ≤20% group presented higher LVEF, LVEDV, and LVESV positive response rate (86%, 59%, and 83%, respectively). Both 20-50% and ≥50% groups exhibited a lower LVEF, LVEDV, and LVESV positive response rate (52% and 42%; 47% and 45%; and 53% and 45%, respectively). Additionally, ≥25% of LVWT <6 mm inclusive of at least one papillary muscle insertion was the only predictor of lack of MR improvement. Lastly, ≥50% group experienced significantly lower 2-year MACE survival free probability.

CONCLUSION

WT evaluated using CT could help to stratify the response to CRT and predict MR improvement and outcomes.

CLINICAL TRIAL REGISTRATION

NCT01097733.

Chemokines profile in patients with chronic heart failure treated with cardiac resynchronization therapy

PURPOSE

Inflammatory mechanisms have been suggested to play a role in the heart failure with reduced ejection fraction (HF-REF) development, but the role of chemokines is largely unknown. Cardiac resynchronization therapy (CRT) may reverse the HF-REF course. We aimed to evaluate selected chemokines concentrations in HF-REF patients and their relationship with disease severity and clinical response to CRT.

MATERIALS AND METHODS

The study included 37 patients (64.1 ± 11.04 years, 6 females) with HF-REF subjected to CRT, controlled prior to implantation and after 6 months. The control population included 26 healthy volunteers (63.9 ± 8.1 years, 8 females). Serum chemokines concentrations were determined using multiplex method.

RESULTS

HF-REF patients were characterized by the higher baseline MIF, NAP-2 and PF4 concentrations and lower Axl, BTC, IL-9, and IL-18 BPa concentrations comparing to controls. After 6 months of CRT only NAP-2 concentration decreased significantly in comparison to the baseline values.

CONCLUSIONS

HF-REF patients present altered chemokines profile compared to the control group. The CRT-related alleviation of HF-REF causes only slight changes in the chemokines concentrations especially in the platelet-associated ones. The precise chemokines role in the HF-REF pathogenesis and their prognostic value remains to be established.

Antegrade Conduction Rescues Right Ventricular Pacing-Induced Cardiomyopathy in Complete Heart Block

BACKGROUND

Right ventricular (RV) pacing-induced cardiomyopathy (PICM) occurs in ∼30% of patients with RV leads. This study evaluated the long-term effects of restoring antegrade conduction with a biological pacemaker in a porcine model of RV PICM.

OBJECTIVES

The goal of this study was to determine if antegrade biological pacing can attenuate RV PICM.

METHODS

In pigs with complete atrioventricular (AV) block, transcription factor T-box 18 (TBX18) was injected into the His bundle region in either of 2 experimental protocols: protocol A sought to prevent PICM, and protocol B sought to reverse PICM. In protocol A, we injected adenoviral vectors expressing TBX18 (or the reporter construct green fluorescent protein) after AV node ablation, and observed the animals for 8 weeks. In protocol B, PICM was established by using AV node ablation and 4 weeks of electronic RV pacing, at which point TBX18 was injected into the His bundle region.

RESULTS

In protocol A, TBX18 biological pacing led to superior chronotropic support (62.4 ± 3 beats/min vs. 50.4 ± 0.4 beats/min; p = 0.01), lower backup pacemaker utilization (45 ± 2.6% vs. 94.6 ± 1.4%; p = 0.001), and greater ejection fraction (58.5 ± 1.3% vs. 46.7 ± 2%; p = 0.001). In protocol B, full-blown RV PICM was evident 4 weeks after complete AV block in both groups; subsequent intervention led to higher mean heart rate (56 ± 2 beats/min vs. 50.1 ± 0.4 beats/min; p = 0.05), less backup pacemaker utilization (53 ± 8.2% vs. 95 ± 1.6%; p = 0.003), and a greater ejection fraction (61.7 ± 1.3% vs. 49 ± 1.6%; p = 0.0003) in TBX18-injected animals versus control animals.

CONCLUSIONS

In a preclinical model, pacemaker-induced cardiomyopathy can be prevented, and reversed, by restoring antegrade conduction with TBX18 biological pacing.

Synergistic prognostication of left ventricular hypertrophy and three-dimensional mechanical dyssynchrony in heart failure

AIMS

In this study, we investigated the prognostic interplay of left ventricular hypertrophy and mechanical dyssynchrony (LVMD), both of which can be measured three-dimensionally by gated myocardial perfusion imaging (MPI), in patients with chronic systolic heart failure (HF).

METHODS AND RESULTS

In 829 consecutive HF patients with reduced left ventricular ejection fraction less than 50%, LVMD was evaluated as a standard deviation (phase SD) of regional onset of mechanical contraction phase angles. A phase histogram was created by Fourier phase analysis applied to regional time-activity curves obtained by gated MPI. Left ventricular mass index (LVMI) was measured by Corridor 4DM version 6.0. Patients were followed up with a primary endpoint of lethal cardiac events (CE) for a mean interval of 34 months. CE were documented in 223 (27%) of the HF patients. The CE group had a greater phase SD and a greater LVMI than those in the non-CE group. Patients in the CE group had a more advanced age, greater New York Heart Association (NYHA) functional class, left ventricular cavity size, and left atrial diameter or septal E/e' and lower kidney or cardiac function than did patients in the non-CE group. Phase SD > 37 and LVMI > 122.7 g/m2 were identified as optimal cut-off values by receiver operating characteristic analyses for discrimination of the most increased risk HF subgroup from others (P < 0.0001). When classified into four patient subgroups using both cut-off values, HF patients with phase SD > 37 (LVMD) and LVMI > 122.7g/m2 had the highest CE rate among the subgroups (P < 0.0001). Univariate analysis and subsequent multivariate analysis with a Cox proportional hazards model showed that phase SD and LVMI were significant independent predictors of CE with hazard ratios of 1.038 (confidence interval [CI], 1.024-1.051, P < 0.0001) and 1.005 (CI, 1.001-1.008, P = 0.0073), respectively, as well as conventional clinical parameters such as age, NYHA class, estimated glomerular filtration rate (eGFR), and BNP concentration. Patients with increased phase SD and LVMI had incrementally improved prognostic values of clinical parameters including age, NYHA functional class, eGFR, and BNP with increases in the global χ2 value: 5.9 for age; 139.5 for age and NYHA; 157.9 for age, NYHA, and eGFR; 163.9 for age, NYHA, eGFR, and BNP; 183.4 for age, NYHA, eGFR, BNP, and phase SD; and 192.5 for age, NYHA, eGFR, BNP, phase SD, and LVMI.

CONCLUSIONS

Three-dimensionally assessed LVMD has independent prognostic values and can improve the risk stratification of chronic HF patients synergistically in combination with conventional clinical parameters.

Optimization of Chronic Cardiac Resynchronization Therapy Using Fusion Pacing Algorithm Improves Echocardiographic Response

Background

Whether reprogramming of cardiac resynchronization therapy (CRT) to increase electrical synchrony translates into echocardiographic improvement remains unclear. SyncAV is an algorithm that allows fusion of intrinsic conduction with biventricular pacing. We aimed to assess whether reprogramming chronically implanted CRT devices with SyncAV is associated with improved echocardiographic parameters.

Methods

Patients at a quaternary center with previously implanted CRT devices with a programmable SyncAV algorithm underwent routine electrocardiography-based SyncAV optimization during regular device clinic visits. This analysis included only patients who could be programmed to the SyncAV algorithm (i.e., in sinus rhythm with intrinsic atrioventricular conduction). Echocardiography was performed before and 6 months after CRT optimization.

Results

Of 64 consecutive, potentially eligible patients who underwent assessment, 34 who were able to undergo SyncAV programming were included. Their mean age was 74 ± 9 years, 41% were female, and 59% had ischemic cardiomyopathy. The mean time from CRT implant to SyncAV optimization was 17.8 ± 8.5 months. At 6-month follow-up, SyncAV optimization was associated with a significant increase in left ventricular ejection fraction (LVEF) (mean LVEF 36.5% ± 13.3% vs 30.9% ± 13.3%; P < 0.001) and a reduction in left ventricular end-systolic volume (LVESV) (mean LVESV 110.5 ± 57.5 mL vs 89.6 ± 52.4 mL; P < 0.001) compared with baseline existing CRT programming.

Conclusion

CRT reprogramming to maximize biventricular fusion pacing significantly increased LVEF and reduced LVESV in patients with chronic CRT devices. Further studies are needed to assess if a continuous fusion pacing algorithm improves long-term clinical outcomes and to identify which patients are most likely to derive benefit.