PR interval identifies clinical response in patients with non-left bundle branch block : a multicenter automatic defibrillator implantation Trial-cardiac resynchronization therapy substudy

Item Type:	Article
Title:	PR interval identifies clinical response in patients with non-left bundle branch block : a multicenter automatic defibrillator implantation Trial-cardiac resynchronization therapy substudy
Creators Name:	Kutyifa, V. and Stockburger, M. and Daubert, J.P. and Holmqvist, F. and Olshansky, B. and Schuger, C. and Klein, H. and Goldenberg, I. and Brenyo, A. and McNitt, S. and Merkely, B. and Zareba, W. and Moss, A.J.
Abstract:	BACKGROUND: In MADIT-CRT, patients with non-LBBB (including RBBB, IVCD) did not have clinical benefit from cardiac resynchronization therapy with defibrillator (CRT-D). We hypothesized that baseline PR-interval modulates clinical response to CRT-D therapy in patients with non-LBBB. METHODS AND RESULTS: Non-LBBB patients (n=537, 30%) were divided in two groups based on their baseline PR-interval as normal (including minimally prolonged) PR (PR < 230 ms), and prolonged PR (PR >/= 230 ms). The primary end point was heart failure (HF) or death. Separate secondary end points included HF events and all-cause mortality. Cox proportional hazards regression models were used to compare risk of end point events by CRT-D to ICD therapy in the PR subgroups. There were 96 patients (22%) with a prolonged PR and 438 patients (78%) with a normal PR interval. In non-LBBB patients with a prolonged PR-interval, CRT-D treatment was associated with a 73% reduction in the risk of HF/Death (HR=0.27, 95% CI: 0.13-0.57, p<0.001) and 81% decrease in the risk of all-cause mortality (HR=0.19, 95% CI: 0.13-0.57, p<0.001) compared to ICD therapy. In non-LBBB patients with normal PR, CRT-D therapy was associated with a trend towards an increased risk of HF/Death (HR=1.45, 95% CI: 0.96-2.19, p=0.078, interaction p-value<0.001) and more than a 2-fold higher mortality (HR=2.14, 95% CI: 1.12-4.09, p=0.022, interaction p-value<0.001) compared to ICD therapy. CONCLUSIONS: The data support the use of CRT-D in MADIT-CRT, non-LBBB patients with a prolonged PR-interval. In non-LBBB patients with a normal PR-interval, implantation of a CRT-D may be deleterious. Clinical Trial Registration: http://clinicaltrials.gov; Unique Identifier: NCT00180271.
Keywords:	Atrioventricular Block, Cardiac Resynchronization Therapy, Defibrillators, Implantable, Heart Failure, Mortality,
Source:	Circulation Arrhythmia and Electrophysiology
ISSN:	1941-3149
Publisher:	American Heart Association
Volume:	7
Number:	4
Page Range:	645-651
Date:	August 2014
Additional Information:	Authors' reply in: Circ Arrhythm Electrophyiol 7(6): 1280.
Official Publication:	https://doi.org/10.1161/CIRCEP.113.001299
PubMed:	View item in PubMed

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