Non-invasive three-dimensional electrical activation mapping to predict cardiac resynchronization therapy response: site of latest left ventricular activation relative to pacing site.

Aims: Pacing remote from the latest electrically activated site (LEAS) in the left ventricle (LV) may diminish response to cardiac resynchronization therapy (CRT). We tested whether proximity of LV pacing site (LVPS) to LEAS, determined by non-invasive three-dimensional electrical activation mapping [electrocardiographic Imaging (ECGI)], increased likelihood of CRT response.
Methods and Results: Consecutive CRT patients underwent ECGI and chest/heart computed tomography 6-24 months of post-implant. Latest electrically activated site and the distance to LVPS (dp) were assessed. Left ventricular end-systolic volume (LVESV) reduction of ≥15% at clinical follow-up defined response. Logistic regression probabilistically modelled non-response; variables included demographics, heart failure classification, left bundle branch block (LBBB), ischaemic heart disease (IHD), atrial fibrillation, QRS duration, baseline ejection fraction (EF) and LVESV, comorbidities, use of CRT optimization algorithm, angiotensin-converting enzyme inhibitor(ACE)/angiotensin-receptor blocker (ARB), beta-blocker, diuretics, and dp. Of 111 studied patients [64 ± 11 years, EF 28 ± 6%, implant duration 12 ± 5 months (mean ± SD), 98% had LBBB, 38% IHD], 67% responded at 10 ± 3 months post CRT-implant. Latest electrically activated sites were outside the mid-to-basal lateral segments in 35% of the patients. dp was 42 ± 23 mm [31 ± 14 mm for responders vs. 63 ± 24 mm non-responders (P < 0.001)]. Longer dp and the lack of use of CRT optimization algorithm were the only independent predictors of non-response [area under the curve (AUC) 0.906]. dp of 47 mm delineated responders and non-responders (AUC 0.931).
Conclusion: The distance between LV pacing site and latest electrical activation is a strong independent predictor for CRT response. Non-invasive electrical evaluation to characterize intrinsic activation and guide LV lead deployment may improve CRT efficacy.
Competing Interests: Conflict of interest: N.V.—consulting fees/honoraria from Abbott, Boston Scientific, Biotronik, Medtronic, and Impulse Dynamics; A.A.—consultant to Boston Scientific, Cairdac, Corvia, Microport CRM, EP Solutions, EPD Philips, and Radcliffe Publishers; he received speaker fees from Boston Scientific, Medtronic, and Microport; he participates in clinical trials sponsored by Boston Scientific, Medtronic, EPD Philips, and XSpline; and has intellectual properties with Boston Scientific, Biosense Webster, and Microport CRM; A.T.—shareholder, consultant, and recipient of the financial research support from EP Solutions and consulting fees/honoraria from Abbott, Biosense Webster, and Medtronic; F.L.—consultant and recipient of the financial research support from Medtronic, Abbott, Boston Scientific, Biotronik, and Microport. All remaining authors have declared no conflicts of interest.
(© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)