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

Global myocardial work index predicts response to biventricular pacing in patients with non-left bundle branch block

AIMS

Cardiac resynchronization therapy (CRT) improves the prognosis of patients with heart failure (HF) and wide QRS complex. However, patients with non-left bundle branch block (LBBB) show a poor response to CRT. This study evaluated myocardial work estimated by pressure-strain loops on echocardiography for predicting response to CRT in patients with non-LBBB.

METHODS AND RESULTS

Of 267 patients who underwent CRT implantation, 54 patients with non-LBBB (mean age, 62 ± 12 years, 72% males, and 24% with ischemic cardiomyopathy) were retrospectively included. Two-dimensional speckle-tracking echocardiography was performed before and at 6-month follow-up in all patients. Myocardial work was estimated by pressure-strain loop analysis using speckle-tracking echocardiography and non-invasive blood pressure measurement. CRT response was defined as a ≥15% decrease in left ventricular end-systolic volume on echocardiography at the 6-month follow-up. The mean left ventricular ejection fraction (LVEF) before implantation was 27% ± 8% in total. Six months after implantation, 18 patients (33%) responded to CRT. The absolute LVEF improvement for responders and non-responders were 5.5% ± 6.9% and 1.3% ± 7.5%, respectively (P = 0.021). Baseline global work index (GWI), which is the average myocardial work based on the pressure-strain loop, was significantly higher in the responder group than in the non-responder group (590 ± 271 vs. 409 ± 216 mmHg%; P = 0.010). Multivariable analysis showed GWI to be an independent predictor of CRT response (odds ratio, 1.109; 95% confidence interval [CI], 1.013-1.213; P = 0.024). Receiver operating characteristic curve analysis determined the cut-off value of GWI for response as 456 mmHg% (AUC 0.700, 95% CI 0.553-0.840; P = 0.019). During the median 37-month follow-up, all-cause death occurred in 21 patients (39%). On multivariable analysis, GWI ≤ 456 mmHg% was independently associated with an increased risk of all-cause mortality (hazard ratio, 2.882; 95% CI, 1.157-7.176; P = 0.023).

CONCLUSIONS

High GWI assessed by speckle-tracking echocardiography and a non-invasively estimated LV pressure curve was independently associated with a favourable response to CRT and improved outcomes in patients with non-LBBB. The use of this non-invasive approach for quantifying myocardial variability and residual contractility can be beneficial for assessing CRT candidates and allow for more accurate patient stratification. Further, large multicentre studies are required to validate these findings.

Cardiac Resynchronization Therapy and Conduction System Pacing

Left bundle branch block (LBBB), initially described in the early 20th century, has become increasingly recognized as one of the leading causes of advanced heart failure (HF). In addition to rapidly growing data on guideline-directed medical therapy, cardiac resynchronization therapy (CRT) via transvenous coronary sinus lead has been the gold-standard therapy, but one-third of the indicated patients do not receive the expected benefits. Recently, cardiac conduction system pacing (CSP) was identified as an alternative to traditional CRT strategy, and multiple data have been published during the last few years. This review will discuss the diagnostic criteria of LBBB and its relation to the development of HF and review available data for traditional CRT as well as CSP in depth.

Win Ratio Analysis of the REVERSE Cardiac Resynchronization Trial

BACKGROUND

The novel win ratio (WR) statistic has emerged as a promising alternative endpoint for the comparison of two treatment groups on multiple endpoints simultaneously, but it has not been used for cardiac resynchronization therapy (CRT) trials. REVERSE was the first multicenter, randomized CRT trial in mild heart failure (HF). The primary result was a non-significant reduction in the proportion of CRT patients with worsened Clinical Composite Score (CCS) compared to control. However, CRT did improve reverse remodeling measures and delayed time to first HF hospitalizations.

OBJECTIVE

To demonstrate the value of the WR for the evaluation of CRT using data from REVERSE.

METHODS

Individual patient data were analyzed using the WR on a hierarchical endpoint at 12 months that included the CCS components: all-cause death, HF hospitalization, crossover or exit due to HF, change in NYHA class from baseline, and the Patient Global Assessment. All pairs of a CRT and a control patient were compared. The WR is the number of CRT wins divided by the number of losses. Reverse remodeling and Quality of Life were assessed in alternative endpoints.

RESULTS

REVERSE included 610 patients randomized between treatment (CRT ON, n=419) and control (CRT OFF, n=191). Comparison of all 80,029 treatment/control pairs resulted in 53.5% wins, 36.9% losses and 9.5% ties. The WR was 1.45 (95% CI:1.17-1.80) showing CRT superiority (p=0.0009).

CONCLUSION

Win ratio analysis confirms the benefits of CRT beyond a single primary endpoint and holds promise for analysis of combined endpoints in CRT and other arrhythmia studies.

Cardiac Resynchronization Therapy Risk-stratified by Magnetic Resonance Imaging and Optimized by Left bundle branch pacing: Results from long term follow-up of MADURAI LBBP study

BACKGROUND

Role of prophylactic implantable-cardioverter-defibrillator(ICD) in nonischemic-cardiomyopathy(NICM) has been a matter of debate. LBBB associated nonischemic-cardiomyopathy (LB-NICM) is a progressive conduction disease, associated with excellent prognosis after left bundle branch pacing(LBBP).

OBJECTIVES

Aim of study was to prospectively assess the long-term clinical outcomes of CRT risk-stratified by LGE-CMR and optimized by LBBP in LB-NICM patients and LVEF≤35%.

METHODS

Pts with LB-NICM, LVEF≤35% and HF were prospectively enrolled from 2019. If scar burden<10% by CMR, LBBP only (Group-I) and if ≥10%, LBBP+ICD(Group-II) was performed.

PRIMARY ENDPOINTS

1-Composite of time to death, HFH or sustained VT/VF;2-Echocardiographic-response(ER)- ΔLVEF ≥15% at 6-months; Secondary endpoints:1-Echocardiographic-hyper-response(EHR;LVEF≥50%) at 6 and 12 months;2-Need for ICD-upgrade(persistent LVEF<35% at 12 months or sustained VT/VF) RESULTS: 225 patients were enrolled after excluding 6-patients. CMR showed <10% scar-burden in 202 patients(group-I;90%). LBBP optimized-dual-chamber(LOT-DDD) was done in 188 patients(93%) and LOT-CRT-P in 4 patients(7%). Scar-burden ≥10% in 23 patients who underwent LBBP+ICD(Group-II). During mean-follow-up 30±19 months, primary composite-endpoint of death,HFH or VT/VF occurred in 6.9% in group-I vs 26.1% in Group-II(HR-16.52;95%CI 3.41-80.28;p=0.0005). ER observed in 78.2%(140/179) in Group-I vs 15.7%(3/19) in Group-II(p<0.0001). Secondary endpoint of EHR(LVEF≥50%) observed in 64.8%vs5.2%, 74.6%vs25% and 82.2%vs25% at 6, 12 and 24 months in group-I and group-II respectively. Predictors of normalization of LV function in group-I include smaller LV volumes, RWPT≤80ms, LVEF 30-35% and absence of scar. Predictors of adverse-clinical-events in group-I include LV dimensions and presence of scar CONCLUSION: Cost effective CRT may be safely provided by MADURAI LBBP approach of risk stratifying LB-NICM patients with LGE-CMR.

Right Ventricular and Left Atrial Strain Predict Volumetric Response to Cardiac Resynchronization Therapy

BACKGROUND

While left-bundle-branch-block-related contraction patterns as well as echocardiography-derived strain are variably associated with the volumetric response to cardiac resynchronization therapy (CRT), the role of CMR-derived strain parameters is unexplored.

METHODS

A total of 50 patients receiving CRT implantation were retrospectively analyzed, all of whom had undergone CMR imaging within one year before, and echocardiography within 6 months before and 6-12 months after CRT implantation. We assessed CMR-derived morphological and functional parameters with regard to the echocardiographic response, defined as a reduction in the left ventricular end-systolic volume of ≥15%.

RESULTS

Among the standard CMR parameters, the indexed right ventricular volumes in end-diastole (RVEDVi) (74.5 ± 19.5 vs. 94.8 ± 30.2 mL/m2, p = 0.006) and end-systole (RVESVi) (43.2 ± 13.3 vs. 61.6 ± 28.8 mL/m2, p = 0.003), as well as the left atrial (LA) area (24.8 ± 3.5 vs. 30.4 ± 9.5 cm2, p = 0.020), differed significantly between CRT responders and non-responders. In strain analysis, CRT responders showed a significantly better LA global longitudinal strain (GLS) (25.1 ± 10.4 vs. 15.3 ± 10.5, p = 0.002), LA global circumferential strain (GCS) (27.9 ± 14.7 vs. 17.1 ± 13.1%, p = 0.012), RV GLS (-25.0 ± 6.5 vs. -18.9 ± 7.6%, p = 0.004) and RV free wall strain (-31.1 ± 7.9 vs. -24.9 ± 9.5, p = 0.017).

CONCLUSIONS

CMR-derived peak septal circumferential strain and RVEDVi correlated with the echocardiographic volumetric response to CRT at 6-12 months.

Cardiac rhythm devices in heart failure with reduced ejection fraction - role, timing, and optimal use in contemporary practice. European Journal of Heart Failure expert consensus document

Guidelines for management of heart failure with reduced ejection fraction (HFrEF) emphasize personalized care, patient engagement, and shared decision-making. Medications and cardiac rhythm management (CRM) devices are recommended with a high level of evidence. However, there are significant disparities: patients who could benefit from devices are frequently referred too late or not at all. Misconceptions about device therapy and the notion that the needs of patients (especially the prevention of sudden cardiac death) can now be met by expanding drug therapies may play a role in these disparities. This state-of-the-art review is produced by members of the DIRECT HF initiative, a patient-centred, expert-led educational programme that aims to advance guideline-directed use of CRM devices in patients with HFrEF. This review discusses the latest evidence on the role of CRM devices in reducing HFrEF mortality and morbidity, and provides practical guidance on patient referral, device selection, implant timing and patient-centred follow-up.

A Prospective Pilot Study for Prognosis of Cardiac Resynchronization Therapy Super-Response Using Electrical and Mechanical Dyssynchrony Assessment in Patients with Heart Failure and Strauss Left Bundle Branch Block Criteria

Electrical and mechanical dyssynchrony (MD) underlies left ventricular (LV) contractile dysfunction in patients with heart failure (HF) and left bundle branch block (LBBB). In some cases, cardiac resynchronization therapy (CRT) almost completely reverses LV contractile dysfunction. The LBBB electrocardiographic Strauss criteria and MD assessment were proposed to improve CRT response. However, using these techniques separately does not improve LV contraction in 20-40% of patients after CRT device implantation. We aimed to evaluate whether the combined use of electrocardiography (ECG), speckle-tracking echocardiography (STE) and cardiac scintigraphy could improve the prognosis of CRT super-response in patients with HF and Strauss LBBB criteria during a 6-month follow-up period. The study prospectively included patients with HF, classified as New York Heart Association (NYHA) functional class (FC) II-III in sinus rhythm with Strauss LBBB criteria and reduced left ventricular ejection fraction (LVEF). Before and 6 months after CRT device implantation, ECG, STE and cardiac scintigraphy were performed. The study's primary endpoint was the NYHA class improvement ≥ 1 and left ventricle end systolic volume decrease > 30% or LVEF improvement > 15% after 6 months of CRT. Based on collected data, we developed a prognostic model regarding the CRT super-response. Out of 54 (100.0%) patients, 39 (72.2%) had a CRT super-response. Patients with CRT super-response were likelier to have a greater S wave amplitude in V2 lead (p = 0.004), higher rates of global longitudinal strain (GLS) (p = 0.001) and interventricular delay (IVD) (p = 0.005). Only three indicators (S wave amplitude in V2 lead, GLS and IVD) were independently associated with CRT super-response in univariable and multivariable logistic regression. We created a prognostic model based on the logistic equation and calculated a cut-off value (>0.73). The resulting ROC curve revealed a discriminative ability with an AUC of 0.957 (sensitivity 87.2%; specificity 100.0%). The electrical and mechanical dyssynchrony assessment using ECG, STE and cardiac scintigraphy is useful in the prediction of CRT super-response in patients with HF and Strauss LBBB criteria during a 6-month follow-up period. Our prognostic model can identify patients who are super-responders to CRT.

Evolving Indications, Challenges, and Advances in Cardiac Resynchronization Therapy for Heart Failure

Cardiac resynchronization therapy (CRT) via biventricular pacing has markedly improved heart failure outcomes over the past two decades. However, some patients show no clinical improvement or evidence of reverse remodeling following device implantation. Challenges include suboptimal patient selection, limitations in the characterization of conduction disease (especially nonspecific interventricular conduction delays), procedural constraints, inappropriate device programming, and delayed referral. Moreover, there remains no formal consensus on evaluating and characterizing CRT efficacy. Underutilization persists among women and minoritized racial and ethnic groups. Targeted research addressing unmet needs has led to evolving guideline indications. Novel electrocardiographic and imaging techniques are continually being developed to improve patient selection and alternate pacing strategies have emerged. Conduction system pacing may allow for a more physiologic approach to CRT. Observational studies and small clinical trials have shown comparable or superior efficacy of conduction system pacing over traditional biventricular pacing; however, more studies are needed. LAY SUMMARY: Cardiac resynchronization therapy via biventricular pacing has transformed heart failure management over the past two decades. This review examines persistent challenges in clinical practice and evolving guideline recommendations. Key issues, including refining patient selection, better characterizing conduction abnormalities, and optimizing device programming, were highlighted. Emerging evidence suggests conduction system pacing as a physiologic alternative to biventricular pacing, with early studies showing promising outcomes. However, rigorous clinical trials are needed to confirm these findings and guide future practice. Advancing CRT necessitates continued innovation and strategies to improve equity and access across diverse populations.

Gated myocardial perfusion SPECT for evaluating left ventricular dyssynchrony in cardiac resynchronization therapy candidates: a systematic review

OBJECTIVES

Cardiac resynchronization therapy (CRT) is an intervention for heart failure patients with reduced ejection fraction who exhibit specific electrocardiographic indicators of electrical dyssynchrony. However, electrical dyssynchrony does not universally correspond to left ventricular mechanical dyssynchrony (LVMD). Gated single-photon emission computed tomography (SPECT) myocardial perfusion allows for the assessment of LVMD, yet its role in the CRT selection process remains debated.

METHODS

We conducted a systematic literature review to critically evaluate the evidence for the prediction and prognostic utility of SPECT for LVMD in assessing LVMD among CRT candidates. The review adhered to PRISMA 2020 Statement criteria and included articles from PubMed, Embase, and Cochrane databases. The quality of evidence was appraised using the Grading of Recommendations, Assessment, Development, and Evaluation framework.

RESULTS

From an initial pool of 1055 records, 33 met the inclusion criteria and provided original data on the predictive value of myocardial perfusion SPECT for LVMD. Most of them measured LVMD according to established recommendations, focusing on phase histogram bandwidth (HBW) and phase histogram standard deviation (PSD). Out of 2066 patients from 27 studies, 62% ( n  = 1214) were qualified as CRT responders. Five studies reported SPECT-based cutoffs for predicting CRT response (HBW ranging 55°-152° and for PSD 20°-54°). Only five studies assessed the prognostic implications of baseline SPECT-measured LVMD, indicating that elevated baseline HBW and PSD values are associated with poorer outcomes.

CONCLUSION

The objective and reproducible measurement of LVMD provided by SPECT underscores its potential as a valuable tool. Such assessment seems to be emerging as a promising adjunctive technique with potential to enhance CRT outcomes.

Multipoint Left Ventricular Pacing as Alternative Approach in Cases of Biventricular Pacing Failure

Cardiac resynchronization therapy (CRT) is a cornerstone in the treatment of dyssynchronous heart failure with reduced ejection fraction. However, the phenomenon of non-response has plagued CRT since its initial application. Notwithstanding issues such as failure to capture the left ventricle, lower-than-required pacing delivery percent, and failure to optimize atrioventricular and interventricular delays, there are patients who fail to exhibit an adequate response to CRT in its classical biventricular pacing (BiVP) form. Several modalities have been proposed as a means to remedy this issue, including pacing the conduction system itself-His or left bundle branch pacing, allowing for intrinsic conduction in some myocardial segments, pacing the left ventricle from multiple points in the coronary sinus (multipoint pacing), or even combining the above (e.g., His/left bundle pacing and BiVP leading to His/left bundle-optimized CRT). In the present review, we present recent evidence for the advantages and disadvantages of each modality and attempt to formulate a pathophysiology and simulation-based strategy to determine the best way forward for delivering CRT in non-responders to BiVP.

Impact of polypharmacy on clinical outcomes in patients with advanced heart failure undergoing cardiac resynchronization therapy

Background

The prevalence rates of heart failure (HF) and hyperpolypharmacy have increased with the aging population. While a negative impact of hyperpolypharmacy on HF clinical outcomes has already been reported, the effects of hyperpolypharmacy on patients with advanced HF with reduced ejection fraction (HFrEF) undergoing cardiac resynchronization therapy (CRT) remain unclear.

Methods

We retrospectively evaluated data from 147 patients with advanced HFrEF who underwent CRT between March 2004 and June 2020. Patients were divided into nonpolypharmacy (<5 medications) and polypharmacy (≥5 medications) groups, as well as nonhyperpolypharmacy (<10 medications) and hyperpolypharmacy (≥10 medications) groups.

Results

The mean age of the study population was 70.6 ± 9.7 years, and 90 patients (67.2%) were male. The median number of medications used was 10 (interquartile range: 7-13, range: 2-24); Kaplan-Meier survival analysis revealed that the hyperpolypharmacy group had a significantly worse long-term survival rate in terms of major adverse cardiovascular events (MACE; p = 0.004) and all-cause mortality (p = 0.005). Long-term survival in terms of MACE and all-cause mortality was not significantly different between the polypharmacy with cardiovascular medication and nonpolypharmacy with cardiovascular medication groups. By contrast, the polypharmacy with noncardiovascular medication group had a significantly worse long-term survival rate in terms of MACE (p = 0.006) and all-cause mortality (p = 0.003) than the nonpolypharmacy with noncardiovascular medication group.

Conclusions

Hyperpolypharmacy was significantly associated with adverse cardiovascular outcomes in patients with advanced HFrEF who underwent CRT. Noncardiovascular polypharmacy may underlie the harmful effects of hyperpolypharmacy.

Impact of Heart Failure Team on Inpatient Rapid Sequencing of Heart Failure Therapy

The management of heart failure (HF) has undergone a paradigm shift from conventional stepwise methods of initiation and the up-titration of HF therapy towards an early, more intensive initiation of pharmacotherapy to improve the prognosis. The aim of this study was to compare the outcomes of patients at the Liverpool Heart and Chest Hospital (LHCH), with new diagnosis of HF, who were reviewed by the inpatient heart failure team (HFT), compared to patients that were not reviewed. A retrospective review of the electronic records of patients admitted with a new diagnosis of HF to the LHCH from May to December 2023 was performed. Admission drugs were similar, apart from betablockers, which were more frequent in the non-HFT group (58% vs. 24.2%; p = 0.002). The length of inpatient stay was longer in the HFT group (median 5.5 days vs. 3 days; p = 0.001) and more likely to be on all four pillars of HF medical therapy (96.8% vs. 0; p < 0.001) within 30 days of discharge. The 30-day and 6-month mortality outcomes were not significantly different. Patients reviewed by the HFT were significantly more likely to receive the four pillars of HF therapy within 30 days of their diagnosis compared to their counterparts at the expense of a longer length of stay.

Prognostic significance of phase analysis using SPECT myocardial perfusion imaging in heart failure: a systematic review and meta-analysis

Left ventricular mechanical dyssynchrony (LVMD) is an important prognostic factor for heart failure (HF). Phase analysis of myocardial perfusion SPECT is actively being researched to evaluate LVMD. We performed a systematic review and meta-analysis on the prognostic significance of LVMD using gated SPECT in HF patient. PubMed, Embase, and the Cochrane library were searched until January 10, 2024, for studies reporting the prognostic value of LVMD in HF patients using gated SPECT for outcomes of all-cause death, cardiac death, or major adverse cardiovascular event (MACE). Hazard ratios (HRs) along with their corresponding 95% confidence intervals (CIs) were combined through meta-analysis employing a random-effects model. Funnel plots and Egger's tests were utilized to evaluate publication bias, and trim-and-fill method were applied where bias was identified. Ten studies (2585 patients) were included; six on MACE and five on all-cause or cardiac death. Prognoses were worse in patients with LVMD assessed by SPECT than in those without LVMD, with the overall pooled HR for MACE being 2.05 (95% CI, 1.65-2.54). The pooled HR for all-cause or cardiac death was 2.08 (95% CI, 1.10-3.94); however, publication bias was present (p = 0.0024), and after adjustment, the prognostic value of LVMD was not statistically significant (HR, 1.24; 95% CI, 0.68-2.23). Assessing LVMD through myocardial perfusion SPECT proves to be a significant indicator of subsequent adverse cardiac events in HF patients. Utilizing phase analysis of SPECT could offer valuable insights for risk assessment and decision-making regarding therapy in HF patients.

Optimizing outcomes from cardiac resynchronization therapy: what do recent data and insights say?

INTRODUCTION

Cardiac Resynchronization Therapy (CRT) is an effective treatment for heart failure (HF) in approximately two-thirds of recipients, with a third remaining CRT 'non-responders.' There is an increasing body of evidence exploring the reasons behind non-response, as well as ways to preempt or counteract it.

AREAS COVERED

This review will examine the most recent evidence regarding optimizing outcomes from CRT, as well as explore whether traditional CRT indeed remains the best first-line therapy for electrical resynchronization in HF. We will start by discussing methods of preempting non-response, such as refining patient selection and procedural technique, before reviewing how responses can be optimized post-implantation. For the purpose of this review, evidence was gathered from electronic literature searches (via PubMed and GoogleScholar), with a particular focus on primary evidence published in the last 5 years.

EXPERT OPINION

Ever-expanding research in the field of device therapy has armed physicians with more tools than ever to treat dyssynchronous HF. Newer developments, such as artificial intelligence (AI) guided device programming and conduction system pacing (CSP) are particularly exciting, and we will discuss how they could eventually lead to truly personalized care by maximizing outcomes from CRT.

Mechanical dyssynchrony as a selection criterion for cardiac resynchronization therapy: Design of the AMEND-CRT trial

AIMS

One third of patients do not improve after cardiac resynchronization therapy (CRT). Septal flash (SF) and apical rocking (ApRock) are deformation patterns observed on echocardiography in most patients eligible for CRT. These markers of mechanical dyssynchrony have been associated to improved outcome after CRT in observational studies and may be useful to better select patients. The aim of this trial is to investigate whether the current guideline criteria for selecting patients for CRT should be modified and include SF and ApRock to improve therapy success rate, reduce excessive costs and prevent exposure to device-related complications in patients who would not benefit from CRT.

METHODS

The AMEND-CRT trial is a multicentre, randomized, parallel-group, double-blind, sham-controlled trial with a non-inferiority design. The trial will include 578 patients scheduled for CRT according to the 2021 ESC guidelines who satisfy all inclusion criteria. The randomization is performed 1:1 to an active control arm ('guideline arm') or an experimental arm ('echo arm'). All participants receive a device, but in the echo arm, CRT is activated only when SF or ApRock or both are present. The outcome of both arms will be compared after 1 year. The primary outcome measures are the average change in left ventricular end-systolic volume and patient outcome assessed using a modified Packer Clinical Composite Score.

CONCLUSIONS

The findings of this trial will redefine the role of echocardiography in CRT and potentially determine which patients with heart failure and a prolonged QRS duration should receive CRT, especially in patients who currently have a class IIa or class IIb recommendation.

Prognostic value of mechanical dyssynchrony in patients with heart failure: a systematic review

BACKGROUND

Heart failure (HF) significantly impacts quality of life and healthcare systems worldwide. Assessing left ventricular mechanical dyssynchrony (LVMD) is crucial for understanding cardiac function and optimizing treatments like cardiac resynchronization therapy (CRT). Phase analysis using gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) has shown promise in predicting outcomes, yet recent comprehensive reviews are lacking.

OBJECTIVE

To systematically assess the prognostic value of phase analysis by gated SPECT MPI in the HF population through a systematic review.

METHODS

We conducted a systematic review by collecting studies from databases including PubMed, CINAHL, and Web of Science. Two reviewers independently performed study selection, data extraction, and risk of bias assessment. Systematic reviews were conducted using Review Manager Software 5.4 and STATA 16.0.

RESULTS

A total of 2004 patients from seven studies were included in our review and analysis. The systematic review indicated that patients with predetermined clinical events had higher PSD [MD = 6.45, 95% CI (5.83, 7.07), p < 0.00001] and PBW [MD = 7.91, 95% CI (5.64, 10.19), p < 0.00001]. The diagnosis of LVMD determined by PSD [HR = 1.05, 95% CI (1.01, 1.08), p = 0.007] was a strong predictor of endpoint events compared to PBW [HR = 1.95, 95% CI (0.48, 7.89), p = 0.35].

CONCLUSIONS

The analysis demonstrated that phase information obtained from gated SPECT MPI is of significant prognostic value in patients with heart dysfunction. It effectively enhances clinical risk models, providing reliable guidance for patient treatment.

Contemporary clinical role of echocardiography in patients with advanced heart failure

Echocardiography represents an essential tool for imagers and clinical cardiologists in the management of patients with heart failure. Advanced heart failure (AdHF) is a more severe and, typically, later stage of HF that exposes patients to a high risk of adverse outcomes, with a 1-year mortality rate of around 50%. Currently, several therapies are available to improve the outcomes of these patients, reduce their mortality rate, and, possibly, delay the need for advanced therapies such as heart transplant and long-term mechanical circulatory support. When accurately performed and interpreted, echocardiography provides crucial information to properly tailor medical and device therapy of patients with AdHF and to identify those at even higher risk. In this review, we present the state of the art of echocardiography applications in the clinical management of patients with AdHF. We will discuss the role of echocardiography chronologically, beginning with the prediction of AdHF, proceeding through diagnosis, and detailing how echocardiography informs clinical decision-making, before concluding with indications for advanced therapies.

Multicenter Hemodynamic Assessment of the LOT-CRT Strategy: When Does Combining Left Bundle Branch Pacing and Coronary Venous Pacing Enhance Resynchronization?: Primary Results of the CSPOT Study

BACKGROUND

Left bundle branch area pacing (LBBAP) may be an alternative to biventricular pacing (BVP) for cardiac resynchronization therapy (CRT). We sought to compare the acute hemodynamic and ECG effects of LBBAP, BVP, and left bundle-optimized therapy CRT (LOT-CRT) in CRT candidates with advanced conduction disease.

METHODS

In this multicenter study, 48 patients with either nonspecific interventricular conduction delay (n=29) or left bundle branch block (n=19) underwent acute hemodynamic testing to determine the change in left ventricular pressure maximal first derivative (LV dP/dtmax) from baseline atrial pacing to BVP, LBBAP, or LOT-CRT.

RESULTS

Atrioventricular-optimized increases in LV dP/dtmax for LOT-CRT (mean, 25.8% [95% CI, 20.9%-30.7%]) and BVP (26.4% [95% CI, 20.2%-32.6%]) were greater than unipolar LBBAP (19.3% [95% CI, 15.0%-23.7%]) or bipolar LBBAP (16.4% [95% CI, 12.7%-20.0%]; P≤0.005). QRS shortening was greater in LOT-CRT (29.5 [95% CI, 23.4-35.6] ms) than unipolar LBBAP (11.9 [95% CI, 6.1-17.7] ms), bipolar LBBAP (11.7 ms [95% CI, 6.4-17.0]), or BVP (18.5 [95% CI, 11.0-25.9] ms), all P≤0.005. Compared with patients with left bundle branch block, patients with interventricular conduction delay experienced less QRS reduction (P=0.026) but similar improvements in LV dP/dtmax (P=0.29). Bipolar LBBAP caused anodal capture in 54% of patients and resulted in less LV dP/dtmax improvement than unipolar LBBAP (18.6% versus 23.7%; P<0.001). Subclassification of LBBAP capture (European Heart Rhythm Association criteria) indicated LBBAP or LV septal pacing in 27 patients (56%) and deep septal pacing in 21 patients (44%). The hemodynamic benefit of adding left ventricular coronary vein pacing to LBBAP depended on baseline QRS duration (P=0.031) and success of LBBAP (P<0.004): LOT-CRT provided 14.5% (5.0%-24.1%) greater LV dP/dtmax improvement and 20.8 (12.8-28.8) ms greater QRS shortening than LBBAP in subjects with QRS ≥171 ms and deep septal pacing capture type.

CONCLUSIONS

In a CRT cohort with advanced conduction disease, LOT-CRT and BVP provided greater acute hemodynamic benefit than LBBAP. Subjects with wider QRS or deep septal pacing are more likely to benefit from the addition of a left ventricular coronary vein lead to implement LOT-CRT.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04905290.

Left bundle branch block-induced dilated cardiomyopathy: Definitions, pathophysiology, and therapy

Left bundle branch block (LBBB) is a frequent finding in patients with heart failure (HF), particularly in those with dilated cardiomyopathy (DCM). LBBB has been commonly described as a consequence of DCM development. However, a total recovery of left ventricular (LV) function after cardiac resynchronization therapy (CRT), observed in patients with LBBB and DCM, has led to increasing acknowledgement of LBBB-induced dilated cardiomyopathy (LBBB-iDCM) as a specific pathological entity. Its recognition has important clinical implications, as LBBB-iDCM patients may benefit from an early CRT strategy rather than medical HF therapy only. At present, there are no definitive diagnostic criteria enabling the universal identification of LBBB-iDCM, and no defined therapeutic approach in this subgroup of patients. This review compiles the main findings about LBBB-iDCM pathophysiology and the current proposed diagnostic criteria and therapeutic approach.

Leadless Ultrasound-Based Cardiac Resynchronization System in Heart Failure

Importance

Approximately 40% of patients with heart failure (HF) who are eligible for cardiac resynchronization therapy (CRT) either fail to respond or are untreatable due to anatomical constraints.

Objective

To assess the safety and efficacy of a novel, leadless, left ventricular (LV) endocardial pacing system for patients at high risk for a CRT upgrade or whose coronary sinus (CS) lead placement/pacing with a conventional CRT system failed.

Design, Setting, and Participants

The SOLVE-CRT study was a prospective multicenter trial enrolling January 2018 through July 2022, with follow-up at 6 months. Data were analyzed from January 17, 2018, through February 15, 2023. The trial combined data from an initial randomized, double-blind study (n = 108) and a subsequent single-arm part (n = 75). It took place at 36 centers across Australia, Europe, and the US. Participants were nonresponders, previously untreatable (PU), or high-risk upgrades (HRU). All participants contributed to the safety analysis. The primary efficacy analysis (n = 100) included 75 PU-HRU patients from the single-arm part and 25 PU-HRU patients from the randomized treatment arm.

Interventions

Patients were implanted with the WiSE CRT System (EBR Systems) consisting of a leadless LV endocardial pacing electrode stimulated with ultrasound energy delivered by a subcutaneously implanted transmitter and battery.

Main Outcomes and Measures

The primary safety end point was freedom from type I complications. The primary efficacy end point was a reduction in mean LV end systolic volume (LVESV).

Results

The study included 183 participants; mean age was 68.1 (SD, 10.3) years and 141 were male (77%). The trial was terminated at an interim analysis for meeting prespecified stopping criteria. In the safety population, patients were either New York Heart Association Class II (34.6%) or III (65.4%). The primary efficacy end point was met with a 16.4% (95% CI, -21.0% to -11.7%) reduction in mean LVESV (P = .003). The primary safety end point was met with an 80.9% rate of freedom from type I complications (P < .001), which included 12 study device system events (6.6%), 5 vascular events (2.7%), 3 strokes (1.6%), and 7 cardiac perforations which mostly occurred early in the study (3.8%).

Conclusions and Relevance

The SOLVE-CRT study has demonstrated that leadless LV endocardial pacing with the WiSE CRT system is associated with a reduction in LVESV in patients with HF. This novel system may represent an alternative to conventional CRT implants in some HF patient populations.

Trial Registration

ClinicalTrials.gov Identifier: NCT0292203.

Longitudinal comparison of dyssynchrony correction and 'strain' improvement by conduction system pacing: LEVEL-AT trial secondary findings

AIMS

Longitudinal dyssynchrony correction and 'strain' improvement by comparable cardiac resynchronization therapy (CRT) techniques is unreported. Our purpose was to compare echocardiographic dyssynchrony correction and 'strain' improvement by conduction system pacing (CSP) vs. biventricular pacing (BiVP) as a marker of contractility improvement during 1-year follow-up.

METHODS AND RESULTS

A treatment-received analysis was performed in patients included in the LEVEL-AT trial (NCT04054895), randomized to CSP or BiVP, and evaluated at baseline (ON and OFF programming) and at 6 and 12 months (n = 69, 32% women). Analysis included intraventricular (septal flash), interventricular (difference between left and right ventricular outflow times), and atrioventricular (diastolic filling time) dyssynchrony and 'strain' parameters [septal rebound, global longitudinal 'strain' (GLS), LBBB pattern, and mechanical dispersion). Baseline left ventricular ejection fraction (LVEF) was 27.5 ± 7%, and LV end-systolic volume (LVESV) was 138 ± 77 mL, without differences between groups. Longitudinal analysis showed LVEF and LVESV improvement (P < 0.001), without between-group differences. At 12-month follow-up, adjusted mean LVEF was 46% with CSP (95% CI 42.2 and 49.3%) vs. 43% with BiVP (95% CI 39.6 and 45.8%), (P = 0.31), and LVESV was 80 mL (95% CI 55.3 and 104.5 mL) vs. 100 mL (95% CI 78.7 and 121.6 mL), respectively (P = 0.66). Longitudinal analysis showed a significant improvement of all dyssynchrony parameters and GLS over time (P < 0.001), without differences between groups. Baseline GLS significantly correlated with LVEF and LVESV at 12-month follow-up.

CONCLUSION

CSP and BiVP provided similar dyssynchrony and 'strain' correction over time. Baseline global longitudinal 'strain' predicted ventricular remodelling at 12-month follow-up.

Left Bundle Branch Block-associated Cardiomyopathy: A New Approach

Left bundle branch block (LBBB) is frequently associated with structural heart disease, and predicts higher rates of morbidity and mortality. In patients with cardiomyopathy (ejection fraction <35%) and LBBB, current guidelines recommend cardiac resynchronisation therapy (CRT) after 3 months of medical therapy. However, studies have suggested that medical therapy alone would be less effective, and the majority of patients would still need CRT at the end of 3 months. Conversely, CRT trials have shown better results and favourable clinical outcomes in patients with LBBB. In the absence of any other known aetiology, LBBB-associated cardiomyopathy represents a potentially reversible form of cardiomyopathy, with the majority of the patients having reverse remodelling after CRT by left bundle branch pacing. This review provides the mechanism, published evidence and role of conduction system pacing for patients with LBBB-associated cardiomyopathy.

Role of Imaging and Biomarkers in Identifying, Monitoring, and Promoting Myocardial Recovery

Reverse remodeling, the overarching concept behind myocardial recovery, describes the process in which the maladaptive cardiac structural and functional alterations are reversed by removing the underlying etiology or by therapy. This review addresses different imaging modalities and biomarkers as possible predictors for reverse remodeling in patients with chronic heart failure. Although echocardiography remains the imaging modality of choice in daily practice, the presence and amount of fibrosis on cardiac magnetic resonance is a better predictor and inversely correlated with the likelihood for reverse remodeling. A decrease in NT-proBNP levels and serum soluble ST3 during follow-up is associated with better clinical and structural outcomes. The role of troponins and galectine-3 is less clear. There is a promising role for microRNAs in the future, although more research is necessary. Accurate predictors of reverse remodeling could help identify patients with an increased likelihood for reverse remodeling and, in turn, improve patient-tailored medicine.

Combination therapy of acupuncture and herbal medicine for heart failure: A systematic review and meta-analysis

BACKGROUND

Heart failure (HF) is characterized by functional or structural dysfunction of the heart, resulting in impaired blood ejection or ventricular filling. Conventional Western Medicine (CWM) remains the mainstay of treatment for HF; however, the occurrence of adverse events (AEs) necessitates the exploration of alternative treatments. Herbal medicine and acupuncture are adjunctive therapies for HF and have shown potential for improving heart function. This systematic review and meta-analysis aimed to assess the effectiveness and safety of acupuncture and herbal medicine in treating HF.

METHODS

PubMed, Embase, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, Citation Information by National Institute of Informatics, KoreaMed, Research Information Sharing Service, and DBpia were searched for randomized controlled trials (RCTs) evaluating the effects of acupuncture and herbal medicine along with CWM as adjunctive treatments for HF, published from inception to May 31, 2024. Treatment effectiveness was determined by evaluating the left ventricular ejection fraction as the primary metric, along with the measurement of the total effective rate, brain natriuretic peptide level, N-terminal prohormone of brain natriuretic peptide level, left ventricular end-diastolic volume, and left ventricular end-systolic volume; the administration of the Minnesota Living with Heart Failure Questionnaire; and the conduct of a 6-minute walk test. Treatment safety was evaluated based on the incidence of AEs. The methodological quality of all included RCTs was assessed using the Cochrane risk of bias tool. A meta-analysis was performed using Review Manager, version 5.4.1.

RESULTS

Of the 133 publications identified, 8 RCTs met the inclusion criteria. The meta-analysis showed significant improvements in left ventricular ejection fraction, brain natriuretic peptide levels, N-terminal prohormone of brain natriuretic peptide levels, left ventricular end-systolic volume, left ventricular end-diastolic volume, and 6-minute walk test results. Additionally, significant differences were observed in the total effective rate and Minnesota Living with Heart Failure Questionnaire responses. No significant medication-related AEs occurred in the intervention group. Conversely, 7 control patients developed well-known AEs associated with CWM.

CONCLUSION

Acupuncture combined with herbal medicine and CWM is more effective than CWM alone, indicating a safe treatment approach. Consequently, the proactive administration of acupuncture alongside herbal medicine to patients with HF can be undertaken without concerns regarding AEs.

CMR feature tracking-based left atrial mechanics predicts response to cardiac resynchronization therapy and adverse outcomes

BACKGROUND

Cardiac resynchronization therapy (CRT) is an established therapy for advanced heart failure (HF) with prolonged QRS duration. However, 30% of patients have shown no benefit from the treatment.

OBJECTIVE

This study aimed to examine the value of left atrial (LA) mechanics by cardiac magnetic resonance (CMR) to predict response to CRT and clinical outcomes.

METHODS

A total of 163 CRT recipients with preimplantation CMR examination were retrospectively recruited. CMR feature tracking was used to evaluate LA size and function. The end points include (1) improvement of at least 5% in left ventricular ejection fraction combined with a reduction of at least 1 New York Heart Association functional class at 6-month follow-up and (2) any all-cause death or HF hospitalization during follow-up.

RESULTS

Overall, 82 (50.3%) were CRT responders. CRT nonresponders had larger LA and worse LA reservoir and booster pump function than did responders (P < .001 for all). LA structural (maximum volume index < 47 mL/m2) and functional (booster pump strain > 8.5%) criteria were incremental to traditional indicators in detecting CRT response (χ2, 40.83 vs 9.98; P < .001). During follow-up (median 41 months), survival free from death or HF hospitalization increased with the number of positive LA criteria (log-rank, P < .001). After adjustment for clinical confounders, the absence of the 2 criteria remained associated with a considerably increased risk of death or HF hospitalization (adjusted hazard ratio 6.2; 95% confidence interval 2.15-17.88; P = .001).

CONCLUSION

The preprocedure LA mechanics evaluated using CMR may be useful to predict response to CRT and improve risk stratification in CRT recipients.

Machine learning of ECG waveforms and cardiac magnetic resonance for response and survival after cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) can lead to marked symptom reduction and improved survival in selected patients with heart failure with reduced ejection fraction (HFrEF); however, many candidates for CRT based on clinical guidelines do not have a favorable response. A better way to identify patients expected to benefit from CRT that applies machine learning to accessible and cost-effective diagnostic tools such as the 12-lead electrocardiogram (ECG) could have a major impact on clinical care in HFrEF by helping providers personalize treatment strategies and avoid delays in initiation of other potentially beneficial treatments. This study addresses this need by demonstrating that a novel approach to ECG waveform analysis using functional principal component decomposition (FPCD) performs better than measures that require manual ECG analysis with the human eye and also at least as well as a previously validated but more expensive approach based on cardiac magnetic resonance (CMR). Analyses are based on five-fold cross validation of areas under the curve (AUCs) for CRT response and survival time after the CRT implant using Cox proportional hazards regression with stratification of groups using a Gaussian mixture model approach. Furthermore, FPCD and CMR predictors are shown to be independent, which demonstrates that the FPCD electrical findings and the CMR mechanical findings together provide a synergistic model for response and survival after CRT. In summary, this study provides a highly effective approach to prognostication after CRT in HFrEF using an accessible and inexpensive diagnostic test with a major expected impact on personalization of therapies.

Speckle Tracking Echocardiography in Patients with Non-Ischemic Dilated Cardiomyopathy Who Undergo Cardiac Resynchronization Therapy: A Narrative Review

Non-ischemic dilated cardiomyopathy (DCM) represents a significant cause of heart failure, defined as the presence of left ventricular (LV) dilatation and systolic dysfunction unexplained solely by abnormal loading conditions or coronary artery disease. Cardiac resynchronization therapy (CRT) has emerged as a cornerstone in the management of heart failure, particularly in patients with DCM. However, identifying patients who will benefit the most from CRT remains challenging. Speckle tracking echocardiography (STE) has garnered attention as a non-invasive imaging modality that allows for the quantitative assessment of myocardial mechanics, offering insights into LV function beyond traditional echocardiographic parameters. This comprehensive review explores the role of STE in guiding patient selection and optimizing outcomes in CRT for DCM. By assessing parameters such as LV strain, strain rate, and dyssynchrony, STE enables a more precise evaluation of myocardial function and mechanical dyssynchrony, aiding in the identification of patients who are most likely to benefit from CRT. Furthermore, STE provides valuable prognostic information and facilitates post-CRT optimization by guiding lead placement and assessing response to therapy. Through an integration of STE with CRT, clinicians can enhance patient selection, improve procedural success rates, and ultimately, optimize clinical outcomes in patients with DCM. This review underscores the pivotal role of STE in advancing personalized management strategies for DCM patients undergoing CRT.

Prognostic value of left ventricular mechanical dyssynchrony indices derived from gated myocardial perfusion SPECT in coronary artery disease: a systematic review and meta-analysis

PURPOSE

Left ventricular mechanical dyssynchrony (LVMD) is an important prognostic factor in coronary artery disease. A growing body of evidence indicates that LVMD parameters derived from phase analysis of gated myocardial SPECT may allow risk stratification for future cardiac events. We performed a systematic review and meta-analysis on the prognostic value of LVMD on gated SPECT in patients with coronary artery disease.

METHODS

PubMed, Embase, and the Cochrane library were searched until August 25, 2022, for studies reporting the prognostic value of LVMD on gated SPECT for outcomes of all-cause death, cardiac death, or major adverse cardiovascular event (MACE) in patients with coronary artery disease. Hazard ratios (HRs) and their 95% confidence intervals (CIs) were meta-analytically pooled using a random-effects model.

RESULTS

Nine studies (26,750 patients) were included in a qualitative synthesis. Among the SPECT LVMD parameters used in various studies, high phase standard deviation, phase bandwidth, and phase entropy were widely evaluated and reported to be associated with high rates of all-cause death, cardiac death, or MACE. For five studies (23,973 patients) in the quantitative synthesis, the pooled HR of LVMD for predicting MACE was 2.81 (95% CI 2.03-3.88). Studies using combined phase parameters to define LVMD showed higher HRs than a study using phase entropy (p = 0.0180).

CONCLUSION

LVMD from gated myocardial SPECT is a significant prognostic factor for coronary artery disease. Phase analysis of gated SPECT may be useful for accurate risk stratification and could be applied for clinical decision-making in such patients.

A Comparative Analysis of Apical Rocking and Septal Flash: Two Views of the Same Systole?

Heart failure (HF) is a complex medical condition characterized by both electrical and mechanical dyssynchrony. Both dyssynchrony mechanisms are intricately linked together, but the current guidelines for cardiac resynchronization therapy (CRT) rely only on the electrical dyssynchrony criteria, such as the QRS complex duration. This possible inconsistency may result in undertreating eligible individuals who could benefit from CRT due to their mechanical dyssynchrony, even if they fail to fulfill the electrical criteria. The main objective of this literature review is to provide a comprehensive analysis of the practical value of echocardiography for the assessment of left ventricular (LV) dyssynchrony using parameters such as septal flash and apical rocking, which have proven their relevance in patient selection for CRT. The secondary objectives aim to offer an overview of the relationship between septal flash and apical rocking, to emphasize the primary drawbacks and benefits of using echocardiography for evaluation of septal flash and apical rocking, and to offer insights into potential clinical applications and future research directions in this area. Conclusion: there is an opportunity to render resynchronization therapy more effective for every individual; septal flash and apical rocking could be a very useful and straightforward echocardiography resource.

Role of speckle tracking echocardiography beyond current guidelines in cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) is a device-based treatment applied to patients with a specific profile of heart failure. According to current guidelines, indication for CRT is given on the basis of QRS morphology and duration, and traditional transthoracic echocardiography is mainly used to estimate left ventricular (LV) ejection fraction. However, the identification of patients who may benefit from CRT remains challenging, since the application of the above-mentioned guidelines is still associated with a high rate of non-responders. The assessment of various aspects of LV mechanics (including contractile synchrony, coordination and propagation, and myocardial work) performed by conventional and novel ultrasound technologies, first of all speckle tracking echocardiography (STE), may provide additional, useful information for CRT patients' selection, in particular among non-LBBB patients, who generally respond less to CRT. A multiparametric approach, based on the combination of ECG criteria and echocardiographic indices of LV dyssynchrony/discoordination would be desirable to improve the prediction of CRT response.

Blood groups and Rhesus status as potential predictors of outcomes in patients with cardiac resynchronisation therapy

Cardiac resynchronisation therapy (CRT) improves prognosis in patients with heart failure (HF) however the role of ABO blood groups and Rhesus factor are poorly understood. We hypothesise that blood groups may influence clinical and survival outcomes in HF patients undergoing CRT. A total of 499 patients with HF who fulfilled the criteria for CRT implantation were included. Primary outcome of all-cause mortality and/or heart transplant/left ventricular assist device was assessed over a median follow-up of 4.6 years (IQR 2.3-7.5). Online repositories were searched to provide biological context to the identified associations. Patients were divided into blood (O, A, B, and AB) and Rhesus factor (Rh-positive and Rh-negative) groups. Mean patient age was 66.4 ± 12.8 years with a left ventricular ejection fraction of 29 ± 11%. There were no baseline differences in age, gender, and cardioprotective medication. In a Cox proportional hazard multivariate model, only Rh-negative blood group was associated with a significant survival benefit (HR 0.68 [0.47-0.98], p = 0.040). No association was observed for the ABO blood group (HR 0.97 [0.76-1.23], p = 0.778). No significant interaction was observed with prevention, disease aetiology, and presence of defibrillator. Rhesus-related genes were associated with erythrocyte and platelet function, and cholesterol and glycated haemoglobin levels. Four drugs under development targeting RHD were identified (Rozrolimupab, Roledumab, Atorolimumab, and Morolimumab). Rhesus blood type was associated with better survival in HF patients with CRT. Further research into Rhesus-associated pathways and related drugs, namely whether there is a cardiac signal, is required.

Assessing Non-invasive Studies to Evaluate Resynchronization Pacing Effectiveness in the Young

Appropriate non-invasive assessments (ECHO/ECG) of cardiac resynchronization pacing therapy (CRT) among younger patients (pts) with/without (w/wo) congenital heart disease (CHD) are not established. Ejection fraction (EF) and QRS can be unreliable due to anatomy, surgical repairs, and pre-existing pacemakers (PM). This study correlates updated non-invasive studies, including newer strain values, with clinical and invasive hemodynamic assessments of CRT response in the young. Sixteen pts (mean age 18.5 ± 6 years, 10/16 with pre-existing pacemakers) underwent CRT for heart failure (NYHA II-III). CHD included septal defects and Tetralogy of Fallot. Assessment of CRT efficacy was based on clinical findings, direct catheterization studies [pressures, contractility indices (dP/dt-max)], ECG changes, and ECHO studies [including updated global (GLS), left atrial strain (LAS), and sphericity indices] pre- and at 1-month and 1-year post-CRT. After 1 year following CRT, all pts improved (II-III to I-II) in clinical NYHA status. Contractility (dP/dt) increased (932 ± 351 vs 561 ± 178.7 mmHg-sec [p = 0.001]). QRS duration shortened only among pts with pre-existing PM (160 ± 25 vs 134 ± 25 ms [p = 0.02]). Standard ECHO parameters, including chamber dimensions and EF, showed no appreciable changes from pre-CRT values. However, endocardial GLS [(- 6.4 vs. - 9.6%) p = 0.0003] and LAS [(- 5.8 vs - 9.3%) p = 0.02] values significantly improved. Although CRT is applicable to younger pts, accurate non-invasive evaluations of response are lacking. This study establishes that newer strain values better correlate with clinical and hemodynamic changes over other parameters and offer more appropriate assessments of CRT response.

Clinical significance of regional constructive and wasted work in patients receiving cardiac resynchronization therapy

Background

Previous studies have shown that global constructive work (CW) and wasted work (WW) predict response to cardiac resynchronization therapy (CRT). This study evaluated the predictive value of regional CW and WW for reverse remodeling and clinical outcomes after CRT.

Methods

We performed a prospective study involving 134 CRT candidates with left bundle branch block and left ventricular ejection fraction ≤35%. Global and regional CW and WW were calculated using pressure-strain loop analysis. CRT response was defined by reverse remodeling as a reduction of ≥15% in left ventricular end-systolic volume after six months.

Results

At six-month follow-up, 92 (69%) patients responded to CRT. Of the regional CW and WW measures, lateral wall (LW) CW and septal WW were most strongly and significantly correlated with reverse remodeling. At multivariate analysis, LW CW and septal WW were both independent determinants of reverse remodeling. When LW CW and septal WW were included in the model, global CW and WW were not independently associated with reverse remodeling. LW CW and septal WW predicted reverse remodeling with an area under the curve (AUC) of 0.783 (95% CI: 0.700-0.866) and 0.737 (95% CI: 0.644-0.831), respectively. Using both variables increased the AUC to 0.832 (95% CI: 0.755-0.908). Both LW CW ≤878 mmHg% (HR 2.01; 95% CI: 1.07-3.79) and septal WW ≤181 mmHg% (HR 2.60; 95% CI: 1.38-4.90) were significant predictors of combined death and HF hospitalization at two-year follow-up.

Conclusion

LW CW and septal WW before CRT are important determinants of reverse remodeling and clinical outcomes.

Quest for the ideal assessment of electrical ventricular dyssynchrony in cardiac resynchronization therapy

This paper reviews the literature on assessing electrical dyssynchrony for patient selection in cardiac resynchronization therapy (CRT). The guideline-recommended electrocardiographic (ECG) criteria for CRT are QRS duration and morphology, established through inclusion criteria in large CRT trials. However, both QRS duration and LBBB morphology have their shortcomings. Over the past decade, various alternative measures of ventricular dyssynchrony have been proposed, ranging from simple options such as vectorcardiography (VCG), ultra-high frequency ECG, and electrical dyssynchrony mapping to more advanced techniques such as ECG imaging electro-anatomic mapping. Despite promising results, none of these methods have yet been widely adopted in daily clinical practice. The VCG is a relatively cost-effective option for potential clinical implementation, as it can be reconstructed from the standard 12‑lead ECG. With the emergence of conduction system pacing, in addition to predicting the outcome of conventional biventricular CRT, the assessment of electrical dyssynchrony holds promise for defining and optimizing the type of resynchronization strategy. Additionally, artificial intelligence has the potential to reveal unknown features for CRT outcomes, and computer models can provide deeper insights into the underlying mechanisms of these features.

Motion correction of wide-detector 4DCT images for cardiac resynchronization therapy planning

BACKGROUND

Lead placement at the latest mechanically activated left ventricle (LV) segments is strongly correlated with response to cardiac resynchronization therapy (CRT). We demonstrate the feasibility of a cardiac 4DCT motion correction algorithm (ResyncCT) in estimating LV mechanical activation for guiding lead placement in CRT.

METHODS

Subjects with full cardiac cycle 4DCT images acquired using a wide-detector CT scanner for CRT planning/upgrade were included. 4DCT images exhibited motion artifact-induced false-dyssynchrony, hindering LV mechanical activation time estimation. Motion-corrupted images were processed with ResyncCT to yield motion-corrected images. Time to onset of shortening (TOS) was estimated in each of 72 endocardial segments. A false-dyssynchrony index (FDI) was used to quantify the extent of motion artifacts in the uncorrected and the ResyncCT images. After motion correction, the change in classification of LV free-wall segments as optimal target sites for lead placement was investigated.

RESULTS

Twenty subjects (70.7 ​± ​13.9 years, 6 female) were analyzed. Motion artifacts in the ResyncCT-processed images were significantly reduced (FDI: 28.9 ​± ​9.3 ​% vs 47.0 ​± ​6.0 ​%, p ​< ​0.001). In 10 (50 ​%) subjects, ResyncCT motion correction yielded statistically different TOS estimates (p ​< ​0.05). Additionally, 43 ​% of LV free-wall segments were reclassified as optimal target sites for lead placement after motion correction.

CONCLUSIONS

ResyncCT significantly reduced motion artifacts in wide-detector cardiac 4DCT images, yielded statistically different time to onset of shortening estimates, and changed the location of optimal target sites for lead placement. These results highlight the potential utility of ResyncCT motion correction in CRT planning when using wide-detector 4DCT imaging.

Understanding the Application of Mechanical Dyssynchrony in Patients with Heart Failure Considered for CRT

Over the past two decades of CRT use, the failure rate has remained around 30-35%, despite several updates in the guidelines based on the understanding from multiple trials. This review article summarizes the role of mechanical dyssynchrony in the selection of heart failure patients for cardiac resynchronization therapy. Understanding the application of mechanical dyssynchrony has also evolved during these past two decades. There is no role of lone mechanical dyssynchrony in the patient selection for CRT. However, mechanical dyssynchrony can complement the electrocardiogram and clinical criteria and improve patient selection by reducing the failure rate. An oversimplified approach to mechanical dyssynchrony assessment, such as just estimating time-to-peak delays between segments, should not be used. Instead, methods that can identify the underlying pathophysiology of HF and are representative of a substrate to CRT should be applied.

Assessing cardiac resynchronization therapy response in heart failure patients: a comparative analysis of efficacy and outcomes between transvenous and epicardial leads

Cardiac resynchronization therapy (CRT) is an effective treatment for selected heart failure (HF) patients. Although transvenous implantation is the standard method, it is not feasible in some patients, so the epicardial lead emerges as an alternative. We aim to compare CRT response, procedure-related complications, and the occurrence of clinical outcomes between patients with transvenous and epicardial leads. In a single-center retrospective study, we enrolled consecutive HF patients submitted to CRT implantation with a defibrillator between 2013 and 2022. Clinical response was defined as an improvement of at least one of the New York Heart Association classes with no occurrence of cardiovascular death or HF hospitalization in the first year of follow-up. Echocardiographic response was attained with an increase in left ventricular ejection fraction 10% or a reduction of left ventricular end-diastolic volume >15% at 6-12 months after CRT implantation. Major adverse cardiovascular events (MACE) (cardiovascular mortality and HF hospitalization) and all-cause mortality were evaluated. From a total of 149 patients, 38% (n=57) received an epicardial lead. Clinical (63% versus 60%, p=0.679) and echocardiographic (63% versus 60%, p=0.679) responses were similar between the transvenous and epicardial groups. Patients in the transvenous group had a shorter hospital stay (2 versus 7 days, p<0.001). Procedure-related complications were comparable between groups (24% versus 28%, p=0.572), but left ventricular lead-related complications were more frequent in the transvenous group (14% versus 2%). During a median follow-up of 4.7 years, the rate of MACE was 30% (n=44), with no differences in both groups (p=0.591), neither regarding HF hospitalization (p=0.917) nor cardiovascular mortality (p=0.060). Nevertheless, the epicardial group had a higher rate of all-cause mortality (35% versus 20%, p=0.005), the majority occurring during long-term follow-up (>12 months), with no deaths in the postoperative period. Considering the comparable rates of CRT response, procedure-related complications, and MACE between groups, we conclude that epicardial lead is a feasible alternative for CRT when transvenous lead implantation is not possible. The occurrence of a higher number of all-cause deaths in epicardial patients in the long-term follow-up was mainly due to infectious complications (unrelated to the lead) and the progression of oncological/chronic diseases.

Echocardiographic mechanical dyssynchrony predicts long-term mortality in patients with cardiac resynchronisation therapy

Cardiac resynchronisation therapy (CRT) is an established treatment for patients with symptomatic heart failure with reduced left ventricular ejection fraction (LVEF ≤ 35%; HFrEF) and conduction disturbances (QRS duration ≥ 130 ms). The presence of mechanical dyssynchrony (MD) on echocardiography has been hypothesised to be of predictive value in determining indication for CRT. This study investigated the impact of MD (apical rocking [AR] and septal flash [SF]) on long-term survival in CRT recipients. HFrEF patients (n = 425; mean age 63.0 ± 10.6 years, 72.3% male, 60.7% non-ischaemic aetiology) with a guideline-derived indication for CRT underwent device implantation. MD markers were determined at baseline and after a mean follow-up of 11.5 ± 8.0 months; long-term survival was also determined. AR and/or SF were present in 307 (72.2%) participants at baseline. During post-CRT follow-up, AR and/or SF disappeared in 256 (83.4%) patients. Overall mean survival was 95.9 ± 52.9 months, longer in women than in men (109.1 ± 52.4 vs. 90.9 ± 52.4 months; p < 0.001) and in younger (< 60 years) versus older patients (110.6 ± 53.7 vs. 88.6 ± 51.1 months; p < 0.001). Patients with versus without MD markers at baseline generally survived for longer (106.2 ± 52.0 vs. 68.9 ± 45.4 months; p < 0.001), and survival was best in patients with resolved versus persisting MD (111.6 ± 51.2 vs. 79.7 ± 47.6 months p < 0.001). Age and MD at baseline were strong predictors of long-term survival in HFrEF patients undergoing CRT on multivariate analysis. Novel echocardiography MD parameters in HFrEF CRT recipients predicted long-term mediated better outcome, and survival improved further when AR and/or SF disappear after CRT implantation.

Multimodality Imaging for Selecting Candidates for CRT: Do We Have a Single Alley to Increase Responders?

Cardiac resynchronization therapy has evolved in recent years to provide a reduction of morbidity and mortality for many patients with heart failure. Its application and optimization is an evolving field and its use requires a multidisciplinary approach for patient and device selection, technical preprocedural planning, and optimization. While echocardiography has always been considered the first line for the evaluation of patients, additional imaging techniques have gained increasing evidence in recent years. Today different details about heart anatomy, function, dissynchrony can be investigated by magnetic resonance, cardiac computed tomography, nuclear imaging, and more, with the aim of obtaining clues to reach a maximal response from the electrical therapy. The purpose of this review is to provide a practical analysis of the single and combined use of different imaging techniques in the preoperative and perioperative phases of cardiac resynchronization therapy, underlining their main advantages, limitations, and information provided.

Myocardial strain of the left ventricle by speckle tracking echocardiography: From physics to clinical practice

Speckle tracking echocardiography (STE) is a reliable imaging technique of recognized clinical value in several settings. This method uses the motion of ultrasound backscatter speckles within echocardiographic images to derive myocardial velocities and deformation parameters, providing crucial insights on several cardiac pathological and physiological processes. Its feasibility, reproducibility, and accuracy have been widely demonstrated, being myocardial strain of the various chambers inserted in diagnostic algorithms and guidelines for various pathologies. The most important parameters are Global longitudinal strain (GLS), Left atrium (LA) reservoir strain, and Global Work Index (GWI): based on large studies the average of the lower limit of normality are -16%, 23%, and 1442 mmHg%, respectively. For GWI, it should be pointed out that myocardial work relies primarily on non-invasive measurements of blood pressure and segmental strain, both of which exhibit high variability, and thus, this variability constitutes a significant limitation of this parameter. In this review, we describe the principal aspects of the theory behind the use of myocardial strain, from cardiac mechanics to image acquisition techniques, outlining its limitation, and its principal clinical applications: in particular, GLS have a role in determine subclinical myocardial dysfunction (in cardiomyopathies, cardiotoxicity, target organ damage in ambulatory patients with arterial hypertension) and LA strain in determine the risk of AF, specifically in ambulatory patients with arterial hypertension.

Imaging in patients with cardiovascular implantable electronic devices: part 1-imaging before and during device implantation. A clinical consensus statement of the European Association of Cardiovascular Imaging (EACVI) and the European Heart Rhythm Association (EHRA) of the ESC

More than 500 000 cardiovascular implantable electronic devices (CIEDs) are implanted in the European Society of Cardiology countries each year. The role of cardiovascular imaging in patients being considered for CIED is distinctly different from imaging in CIED recipients. In the former group, imaging can help identify specific or potentially reversible causes of heart block, the underlying tissue characteristics associated with malignant arrhythmias, and the mechanical consequences of conduction delays and can also aid challenging lead placements. On the other hand, cardiovascular imaging is required in CIED recipients for standard indications and to assess the response to device implantation, to diagnose immediate and delayed complications after implantation, and to guide device optimization. The present clinical consensus statement (Part 1) from the European Association of Cardiovascular Imaging, in collaboration with the European Heart Rhythm Association, provides comprehensive, up-to-date, and evidence-based guidance to cardiologists, cardiac imagers, and pacing specialists regarding the use of imaging in patients undergoing implantation of conventional pacemakers, cardioverter defibrillators, and resynchronization therapy devices. The document summarizes the existing evidence regarding the use of imaging in patient selection and during the implantation procedure and also underlines gaps in evidence in the field. The role of imaging after CIED implantation is discussed in the second document (Part 2).

Indications for Cardiac Resynchronization Therapy in Patients with Congenital Heart Disease

Heart failure in patients with congenital heart disease (CHD) stems from unique causes compared with the elderly. Patients with CHD face structural abnormalities and malformations present from birth, leading to altered cardiac function and potential complications. In contrast, elderly individuals primarily experience heart failure due to age-related changes and underlying cardiovascular conditions. Cardiac resynchronization therapy (CRT) can benefit patients with CHD, although it presents numerous challenges. The complexities of CHD anatomy and limited access to appropriate venous sites for lead placement make CRT implantation demanding.

The Micra Transcatheter Pacing System: past, present and the future

Leadless permanent pacemakers represent an important innovation in cardiac device developments. Although transvenous permanent pacemakers have become indispensable in managing bradyarrhythmia and saving numerous lives, the use of transvenous systems comes with notable risks tied to intravascular leads and subcutaneous pockets. This drawback has spurred the creation of leadless cardiac pacemakers. Within this analysis, we compile existing clinical literature and proceed to evaluate the efficacy and safety of the Micra Transcatheter Pacing System. We also delve into the protocols for addressing a malfunctioning or end-of-life Micra as well as device extraction. Lastly, we explore prospects in this domain, such as the emergence of entirely leadless cardiac resynchronization therapy-defibrillator devices.

Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023

Central Illustration : Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023 Proposal for including strain in the integrated diastolic function assessment algorithm, adapted from Nagueh et al.67 Am: mitral A-wave duration; Ap: reverse pulmonary A-wave duration; DD: diastolic dysfunction; LA: left atrium; LASr: LA strain reserve; LVGLS: left ventricular global longitudinal strain; TI: tricuspid insufficiency. Confirm concentric remodeling with LVGLS. In LVEF, mitral E wave deceleration time < 160 ms and pulmonary S-wave < D-wave are also parameters of increased filling pressure. This algorithm does not apply to patients with atrial fibrillation (AF), mitral annulus calcification, > mild mitral valve disease, left bundle branch block, paced rhythm, prosthetic valves, or severe primary pulmonary hypertension.

Cardiac Magnetic Resonance Identifies Responders to Cardiac Resynchronization Therapy with an Assessment of Septal Scar and Left Ventricular Dyssynchrony

Background: The response to cardiac resynchronization therapy (CRT) depends on septal viability and correction of abnormal septal motion. This study investigates if cardiac magnetic resonance (CMR) as a single modality can identify CRT responders with combined imaging of pathological septal motion (septal flash) and septal scar. Methods: In a prospective, multicenter, observational study of 136 CRT recipients, septal scar was assessed using late gadolinium enhancement (LGE) (n = 127) and septal flash visually from cine CMR sequences. The primary endpoint was CRT response, defined as ≥15% reduction in LV end-systolic volume with echocardiography after 6 months. The secondary endpoint was heart transplantation or death of any cause assessed after 39 ± 13 months. Results: Septal scar and septal flash were independent predictors of CRT response in multivariable analysis (both p < 0.001), while QRS duration and morphology were not. The combined approach of septal scar and septal flash predicted CRT response with an area under the curve of 0.86 (95% confidence interval (CI): 0.78-0.94) and was a strong predictor of long-term survival without heart transplantation (hazard ratio 0.27, 95% CI: 0.10-0.79). The accuracy of the approach was similar in the subgroup with intermediate (130-150 ms) QRS duration. The combined approach was superior to septal scar and septal flash alone (p < 0.01). Conclusions: The combined assessment of septal scar and septal flash using CMR as a single-image modality identifies CRT responders with high accuracy and predicts long-term survival.

Ventricular dyssynchrony late after the Fontan operation is associated with decreased survival

BACKGROUND

Ventricular dyssynchrony and its relationship to clinical outcomes is not well characterized in patients following Fontan palliation.

METHODS

Single-center retrospective analysis of cardiac magnetic resonance (CMR) imaging of patients with a Fontan circulation and an age-matched healthy comparison cohort as controls. Feature tracking was performed on all slices of a ventricular short-axis cine stack. Circumferential and radial strain, strain rate, and displacement were measured; and multiple dyssynchrony metrics were calculated based on timing of these measurements (including standard deviation of time-to-peak, maximum opposing wall delay, and maximum base-to-apex delay). Primary endpoint was a composite measure including time to death, heart transplant or heart transplant listing (D/HTx).

RESULTS

A total of 503 cases (15 y; IQR 10, 21) and 42 controls (16 y; IQR 11, 20) were analyzed. Compared to controls, Fontan patients had increased dyssynchrony metrics, longer QRS duration, larger ventricular volumes, and worse systolic function. Dyssynchrony metrics were higher in patients with right ventricular (RV) or mixed morphology compared to those with LV morphology. At median follow-up of 4.3 years, 11% had D/HTx. Multiple risk factors for D/HTx were identified, including RV morphology, ventricular dilation, dysfunction, QRS prolongation, and dyssynchrony. Ventricular dilation and RV morphology were independently associated with D/HTx.

CONCLUSIONS

Compared to control LVs, single right and mixed morphology ventricles in the Fontan circulation exhibit a higher degree of mechanical dyssynchrony as evaluated by CMR-FT. Dyssynchrony indices correlate with ventricular size and function and are associated with death or need for heart transplantation. These data add to the growing understanding regarding factors that can be used to risk-stratify patients with the Fontan circulation.

Echocardiographic Patterns of Abnormal Septal Motion: Beyond Myocardial Ischemia

Abnormal septal motion (ASM), which often is associated with myocardial ischemia, is also observed in other diseases. Owing to the position of the interventricular septum (IVS) in the heart, its movement not only relies on contractile properties but is also affected by the pressure gradient between the 2 ventricles and by the mode of electrical activation. Echocardiography allows the operator to focus on the motion of the IVS, analyzing its characteristics and thereby gaining information about the possible underlying pathophysiological mechanism. In this review, we focused on the main echocardiographic patterns of ASM that are not related to a failure of contractile properties of the septum (i.e., acute coronary syndrome and cardiomyopathies), showing their pathophysiological mechanisms and underlining their diagnostic usefulness in clinical practice.