Real-Time X-MRI-Guided Left Ventricular Lead Implantation for Targeted Delivery of Cardiac Resynchronization Therapy

doi:10.1016/j.jacep.2017.01.018

JACC: Clinical Electrophysiology

Volume 3, Issue 8, August 2017, Pages 803-814

https://doi.org/10.1016/j.jacep.2017.01.018 Get rights and content

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Abstract

Objectives

This study sought to test the feasibility of a purpose-built, integrated software platform to process, analyze, and overlay cardiac magnetic resonance (CMR) data in real time within a combined cardiac catheter laboratory and magnetic resonance imaging scanner suite (X-MRI) to guide left ventricular (LV) lead implantation.

Background

Suboptimal LV lead position is a major determinant of poor cardiac resynchronization therapy (CRT) response, and the optimal site is highly patient specific. Pacing myocardial scar is associated with poorer outcomes; conversely, targeting latest mechanical activation (LMA) may improve them.

Methods

Fourteen patients (age 74 ± 5.1 years; New York Heart Association functional class: 2.7 ± 0.4; 86% ischemic with ejection fraction 27 ± 7.6%; QRSd: 157 ± 19 ms) underwent CMR followed by immediate CRT implantation using derived scar and dyssynchrony data, overlaid onto fluoroscopy in an X-MRI suite. Rapid LV segmentation enabled detailed scar quantification, identification of LMA segments, and selection of myocardial targets. At coronary venography, the CMR-derived 3-dimensional shell was fused, enabling identification of viable venous targets subtended by target segments for LV lead placement.

Results

The platform was successful in all 14 patients, of whom 10 (71%) were paced in pre-procedurally defined target segments. Pacing in CMR-defined target segments (out of scar) showed a significant decrease in the LV capture threshold (mean difference: 2.4 [1.5 to 3.2]; p < 0.001) and shorter paced QRS duration (mean difference: 25 [15 to 34]; p < 0.001) compared with pacing in areas of CMR determined scar. In 5 (36%) patients with extensive scar in the posterolateral wall, CMR guidance enabled successful lead delivery in an alternative anatomically favorable site. Radiation dose and implant times were similar to historical controls (p = NS).

Conclusions

Real-time CMR-guided LV lead placement is feasible and achievable in a single clinical setting and may prove helpful to preferentially select sites for LV lead placement.

Graphical abstract

Key Words

cardiac magnetic resonance (CMR)

cardiac resynchronization therapy (CRT) image guidance

image overlay

targeted LV lead placement

Abbreviations and Acronyms

CMR

cardiac magnetic resonance

CRT

cardiac resynchronization therapy

coronary sinus

computed tomography

3-dimensional

flip angle

LGE

late gadolinium enhancement

left ventricular

QLV

first ventricular depolarization (earliest onset QRS duration on surface 12-lead electrocardiogram) to the nadir signal on the LV lead electrogram

echo time

repetition time

X-MRI

cardiac catheter laboratory and MRI scanner in the same facility with the ability to transfer patients from one to the other

Cited by (0)

: This research was supported from Innovate UK (32684-234174), National Institute for Health Research Biomedical Research Centre based at Guy’s and St Thomas NHS Foundation Trust and Kings College London. Dr. Behar acknowledges support from the Rosetrees Trust. Dr. Claridge has received research fellowship funding from St Jude Medical Ltd. Dr. Jackson has received research fellowship funding from Medtronic Inc. Dr. Rinaldi is consultant to St Jude Medical Ltd., Medtronic, and Spectranetics; and receives research funding from St. Jude Medical and Medtronic, Boston Scientific, and Livanova. Drs. Mountney and Toth are employees of Siemens Healthcare Ltd., Frimley, United Kingdom. Ms. Reiml, Mr. Fahn, and Dr. Brost are employees of Siemens Healthcare GmbH, Erlangen, Germany.

: Drs Rhode and Rinaldi contributed equally to this work and are joint senior authors on this paper.

: All authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.