Targeting the latest site of left ventricular mechanical activation is associated with improved long-term outcomes for recipients of Cardiac Resynchronization Therapy

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.

Safety and efficacy of orthodromic snare technique in left ventricular lead delivery in cardiac resynchronization implantation

BACKGROUND

Cardiac resynchronization therapy (CRT) improves ventricular function, but a positive response to CRT is often limited due to left ventricular (LV) lead placement in a suboptimal position. Complex coronary venous anatomy can hinder the placement of an LV lead in the target vessel, leading to poor CRT response.

OBJECTIVE

To report experience with snare-assisted LV lead delivery in CRT and compare outcomes with the conventional LV lead delivery.

METHODS

This is a single-center retrospective case-control study of CRT implants between 2016 and 2021. Snare-assisted lead delivery was performed in cases where conventional lead placement failed or when a preferred target vessel had anatomy amenable to the technique. Safety and outcomes were compared to conventional LV lead placement cases.

RESULTS

Among 180 CRT cases, 33 were snare-assisted, and 147 were conventional LV lead placements. Median follow-up was 924 days in the snare and 618.5 days in the control group. The lead placement was successful in 28/33 snare and 138/147 control cases. A mid-vessel segment was attained in 89.3% of snare and 72.5% of control cases(p = .03). The apical position was more frequently observed in the control group (26.8% vs. 7.1%, p = .03). All-cause mortality trended lower in the snare group (6.1%) compared to (17.1%) in the control group (p = .13).

CONCLUSION

Snare-assisted LV lead delivery is a safe and effective technique that can be utilized for overcoming complex venous anatomy.

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.

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.