Radial strain imaging-guided lead placement for improving response to cardiac resynchronization therapy in patients with ischaemic cardiomyopathy: the raise cardiac resynchronization therapy trial

Optimizing CRT Lead Placement Accuracy With CMR-Guided On-Screen Targeting: A Randomized Controlled Trial (ADVISE-CRT III)

BACKGROUND

To improve cardiac resynchronization therapy (CRT) an on-screen image-guidance platform, CARTBox-Suite (CART-Tech B.V.), was developed to identify left ventricular pacing electrode (LVPE) implantation sites and facilitate precise LVPE placement. This multicenter randomized trial evaluated the efficacy of image guidance on LVPE implantation accuracy and its impact on left ventricular end-systolic volume (LVESV) reduction 6 months after CRT.

OBJECTIVES

The aim of this trial is to improve the accuracy and efficacy of LVPE placement in CRT.

METHODS

A total of 131 heart failure patients (80% with Class I CRT indication) were enrolled across 7 hospitals in the Netherlands. CARTBox-Suite, which utilizes a cloud-based AI algorithm, was used to identify a target area with late mechanical activation based on cardiac magnetic resonance imaging. Scarred areas marked by late gadolinium enhancement were excluded. Patients were randomized to image-guided implantation, with on-screen guidance during the procedure or conventional implantation.

RESULTS

The primary endpoint, LVPE implantation in the target area, was achieved significantly more often in the image-guided group (66.7% vs 29.2%; P < 0.001). The secondary endpoint was fewer LVPE placed in scarred areas in the image-guided group (7.1% vs 36.4%; P = 0.006). Mean LVESV reduction was greater in the image-guided group (43.2% vs. 37.6%), although not significantly (P = 0.166). Patients with myocardial scar showed greater LVESV reduction with image guidance (40.7% vs 27.7%; P = 0.028).

CONCLUSIONS

Image-guided implantation resulted in significantly more LVPE placed in the target area and greater LVESV reduction in patients with myocardial scar.

Recent Advances in Cardiac Resynchronization Therapy: Current Treatment and Future Direction

Cardiac Resynchronization Therapy (CRT) has been established as a major component of heart failure management, resulting in a significant reduction in patient morbidity and death for patients with increased QRS duration, low left ventricular ejection fraction (LVEF), and high risk of arrhythmias. The ability to synchronize both ventricles, lower heart failure hospitalizations, and optimize clinical outcomes are some of the attractive characteristics of biventricular pacing, or CRT. However, the high rate of CRT non-responders has led to the development of new modalities including leadless CRT pacemakers (CRT-P) and devices focused on conduction system pacing (CSP). This comprehensive review aims to present recent findings from CRT clinical trials and systematic reviews that have been published that will likely guide future directions in patient care.

Selection of candidates for cardiac resynchronization therapy and implantation management: an Italian survey promoted by the Italian Association of Arrhythmology and Cardiac Pacing

BACKGROUND

Cardiac resynchronization therapy (CRT) represents an effective heart failure treatment, associated with reduction in mortality and heart failure hospitalizations. This Italian survey aimed to address relevant CRT issues.

METHODS

An online survey was administered to AIAC members.

RESULTS

One hundred and five electrophysiologists participated, with a median of 40 (23-70) CRT implantations/year (33% in high-volume centres). Forty-five percent of respondents (especially working in high-volume centres) reported an increase in CRT implantations in the last 2 years, in 16% a decrease, and in 38% CRT remained stable. Seventy-five percent of respondents implanted CRT only in patients with European Heart Rhythm Association (EHRA) class I indications. All operators collected ECG and echocardiography before implantation. Eighty-five percent of respondents selected coronary sinus target vein empirically, whereas 10% used mechanical and/or electrical delay techniques. Physicians working in high-volume centres reported a lower failure rate compared with others (16 vs. 34%; P = 0.03). If the coronary sinus lead could not be positioned in the target branch, 80% placed it in another vein, whereas 16% opted for a surgical approach or for conduction system pacing (CSP). Eighty percent accomplished CRT optimization in all patients, 17% only in nonresponders. Regarding anticoagulation, high agreement with EHRA guidelines emerged.

CONCLUSION

CRT represents a valid therapeutic option in heart failure treatment. Nowadays, CRT implantations remain stable and are mainly performed in patients with class I indications. ECG remains the preferred tool for patient selection, whereas imaging is increasingly used to determine the left pacing target area. In most patients, the left ventricular lead can be successfully positioned in the target vein, but in some cases, the result can be unsatisfactory; however, the decision to explore alternative resynchronization approaches is rarely pursued.

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.

[History of cardiac resynchronization therapy : 30 years of electrotherapeutic management for heart failure]

The first permanent biventricular pacing system was implanted more than 30 years ago. In this article, the historical development of cardiac resynchronization therapy (CRT), starting with the pathophysiological concept, followed by the initial "proof of concept" studies and finally the large prospective-randomized studies that led to the implementation of CRT in heart failure guidelines, is outlined. Since the establishment of CRT, both an expansion of indications, e.g., for patients with mild heart failure and atrial fibrillation, but also the return to patients with broad QRS complex and left bundle branch block who benefit most of CRT has evolved. New techniques such as conduction system pacing will have major influence on pacemaker therapy in heart failure, both as an alternative or adjunct to CRT.

Left ventricular lead placement in cardiac resynchronization therapy: Current data and potential explanations for the lack of benefit

The present article reviews the literature on image-guided cardiac resynchronization therapy (CRT) studies. Improved outcome to CRT has been associated with the placement of a left ventricular (LV) lead in the latest activated segment free from scar. The majority of randomized controlled trials investigating guided LV lead implantation did not show superiority over conventional implantation approaches. Several factors may contribute to this paradoxical observation, including inclusion criteria favoring patients with left bundle branch block who already respond well to conventional anatomical LV lead implantation, differences in activation wavefronts during simultaneous right ventricular and LV pacing, incorrect definition of target regions, and limitations in coronary venous anatomy that prevent access to target regions that are detected by imaging. It is imperative that exclusion of patients lacking access to target regions from these studies would lead to larger benefit of image-guided CRT.

Targeted left ventricular lead positioning to the site of latest activation in cardiac resynchronization therapy: a systematic review and meta-analysis

AIMS

Several studies have evaluated the use of electrically- or imaging-guided left ventricular (LV) lead placement in cardiac resynchronization therapy (CRT) recipients. We aimed to assess evidence for a guided strategy that targets LV lead position to the site of latest LV activation.

METHODS AND RESULTS

A systematic review and meta-analysis was performed for randomized controlled trials (RCTs) until March 2023 that evaluated electrically- or imaging-guided LV lead positioning on clinical and echocardiographic outcomes. The primary endpoint was a composite of all-cause mortality and heart failure hospitalization, and secondary endpoints were quality of life, 6-min walk test (6MWT), QRS duration, LV end-systolic volume, and LV ejection fraction. We included eight RCTs that comprised 1323 patients. Six RCTs compared guided strategy (n = 638) to routine (n = 468), and two RCTs compared different guiding strategies head-to-head: electrically- (n = 111) vs. imaging-guided (n = 106). Compared to routine, a guided strategy did not significantly reduce the risk of the primary endpoint after 12-24 (RR 0.83, 95% CI 0.52-1.33) months. A guided strategy was associated with slight improvement in 6MWT distance after 6 months of follow-up of absolute 18 (95% CI 6-30) m between groups, but not in remaining secondary endpoints. None of the secondary endpoints differed between the guided strategies.

CONCLUSION

In this study, a CRT implantation strategy that targets the latest LV activation did not improve survival or reduce heart failure hospitalizations.

Plasma Extracellular Vesicles as Liquid Biopsy to Unravel the Molecular Mechanisms of Cardiac Reverse Remodeling Following Resynchronization Therapy?

Cardiac resynchronization therapy (CRT) has become a valuable addition to the treatment options for heart failure, in particular for patients with disturbances in electrical conduction that lead to regionally different contraction patterns (dyssynchrony). Dyssynchronous hearts show extensive molecular and cellular remodeling, which has primarily been investigated in experimental animals. Evidence showing that at least several miRNAs play a role in this remodeling is increasing. A comparison of results from measurements in plasma and myocardial tissue suggests that plasma levels of miRNAs may reflect the expression of these miRNAs in the heart. Because many miRNAs released in the plasma are included in extracellular vesicles (EVs), which protect them from degradation, measurement of myocardium-derived miRNAs in peripheral blood EVs may open new avenues to investigate and monitor (reverse) remodeling in dyssynchronous and resynchronized hearts of patients.