Carter, Kris

Drangova, Maria

Fine, Nowell

Gula, Lorne

Klein, George

Krahn, Andrew

Leong-Sit, Peter

McCarty, David

Scholl, David

Skanes, Allan

Stirrat, John

White, James A

Wong, Jorge A

Yee, Raymond

English

PubMed

Drangova Maria

Klein George

Leong-Sit Peter

Skanes Allan

Gula Lorne

Krahn Andrew

Fine Nowell

McCarty David

Carter Kris

Stirrat John

Yee Raymond

Scholl David

Wong Jorge A

White James A

Directory of Open Access Journals

Journal of Cardiovascular Magnetic Resonance

Paced segment characteristics predict clinical response to cardiac resynchronization therapy: results from the multimodality imaging assessment of pacing intervention in heart failure (MAPIT-HF) study

Jorge A Wong

David Scholl

Raymond Yee

John Stirrat

Kris Carter

David McCarty

Nowell Fine

Andrew Krahn

Lorne Gula

Allan Skanes

Peter Leong-Sit

George Klein

Maria Drangova

James A White

Crossref

ORAL PRESENTATION Open AccessPaced segment characteristics predict clinicalresponse to cardiac resynchronization therapy:results from the multimodality imagingassessment of pacing intervention in heart failure(MAPIT-HF) studyJorge A Wong*, David Scholl, Raymond Yee, John Stirrat, Kris Carter, David McCarty, Nowell Fine, Andrew Krahn,Lorne Gula, Allan Skanes, Peter Leong-Sit, George Klein, Maria Drangova, James A WhiteFrom 2011 SCMR/Euro CMR Joint Scientific SessionsNice, France. 3-6 February 2011IntroductionCardiac Resynchronization Therapy (CRT) has beenshown to improve quality of life and decrease mortalityin heart failure patients. However, up to 40% of patientsfail to respond to this therapy. Validation of a responseprediction model that incorporates both myocardial scarand dyssynchrony of the paced myocardial segmentswould allow for a targeted approach to CRT leaddelivery.MethodsPatients planned for CRT under standard indicationswere prospectively enrolled. Serial short-axis tagged cineand delayed enhancement MRI was performed usingstandard imaging protocols. Echocardiography and gatedCT Angiography (CTA) were performed at baseline and3 months post-implantation. The repeat CTA was per-formed for accurate lead tip localization to a 16-segmentmodel. Dyssynchrony was measured for each segment(time to maximal radial strain, Trs) from serial short-axis tagged MRI and expressed in milliseconds fromonset of pulse trigger (InTag, OsirX). A segmental scarscore was then assigned using a blinded visual interpre-tation (score 0 to 4). The number of response predictionrules met was determined for each patient as follows: 1)LV lead tip placed on a dyssynchronous segment (Trs >130msec), 2) LV lead tip placed on a viable segment(scar score <2), 3) RV lead tip placed on a viablesegment (scar score <2). Clinical response to CRT,defined as a >=15% reduction in LVESV by echocardio-graphy, was correlated to the number of predictionrules met.ResultsForty consecutive patients were enrolled with a meanage and ejection fraction of 67.0 ± 8.6 years and 25.6 ±6.6%, respectively. Twenty four patients (60%) met clini-cal response criteria with a mean reduction in LVESV of20.5 ± 16.5% compared to a rise of 1.4 ± 6.3% in non-responders (p<0.001). A strong correlation was seenbetween the number of prediction rules met and clinicalresponse to CRT. In patients with 3, 2, 1 and 0 predic-tion rules met, the response rates were 100%, 92%, 58%and 40%, respectively (p<0.001). A strong correlationwas also seen between the number of prediction rulesand the mean reduction in LVESV [28%, 14% and 5%reduction in those with 3, 2 and 1 rules met, respec-tively (p=0.002)].ConclusionsDyssynchrony and scar characteristics of the paced myo-cardial segments are strongly correlated with clinicalresponse to CRT. A simple 3-point prediction modelincorporating these variables appears to be highly pre-dictive of response, and may be valuable for the selec-tion of optimal pacing targets for CRT.University of Western Ontario, London, ON, CanadaWong et al. Journal of Cardiovascular Magnetic Resonance 2011, 13(Suppl 1):O50http://jcmr-online.com/content/13/S1/O50© 2011 Wong et al; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative CommonsAttribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction inany medium, provided the original work is properly cited.Published: 2 February 2011doi:10.1186/1532-429X-13-S1-O50Cite this article as: Wong et al.: Paced segment characteristics predictclinical response to cardiac resynchronization therapy: results from themultimodality imaging assessment of pacing intervention in heartfailure (MAPIT-HF) study. Journal of Cardiovascular Magnetic Resonance2011 13(Suppl 1):O50.Submit your next manuscript to BioMed Centraland take full advantage of: • Convenient online submission• Thorough peer review• No space constraints or color figure charges• Immediate publication on acceptance• Inclusion in PubMed, CAS, Scopus and Google Scholar• Research which is freely available for redistributionSubmit your manuscript at www.biomedcentral.com/submitWong et al. Journal of Cardiovascular Magnetic Resonance 2011, 13(Suppl 1):O50http://jcmr-online.com/content/13/S1/O50Page 2 of 2

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ORAL PRESENTATION Open Access
Paced segment characteristics predict clinical
response to cardiac resynchronization therapy:
results from the multimodality imaging
assessment of pacing intervention in heart failure
(MAPIT-HF) study
Jorge A Wong*, David Scholl, Raymond Yee, John Stirrat, Kris Carter, David McCarty, Nowell Fine, Andrew Krahn,
Lorne Gula, Allan Skanes, Peter Leong-Sit, George Klein, Maria Drangova, James A White
From 2011 SCMR/Euro CMR Joint Scientific Sessions
Nice, France. 3-6 February 2011
Introduction
Cardiac Resynchronization Therapy (CRT) has been
shown to improve quality of life and decrease mortality
in heart failure patients. However, up to 40% of patients
fail to respond to this therapy. Validation of a response
prediction model that incorporates both myocardial scar
and dyssynchrony of the paced myocardial segments
would allow for a targeted approach to CRT lead
delivery.
Methods
Patients planned for CRT under standard indications
were prospectively enrolled. Serial short-axis tagged cine
and delayed enhancement MRI was performed using
standard imaging protocols. Echocardiography and gated
CT Angiography (CTA) were performed at baseline and
3 months post-implantation. The repeat CTA was per-
formed for accurate lead tip localization to a 16-segment
model. Dyssynchrony was measured for each segment
(time to maximal radial strain, Trs) from serial short-
axis tagged MRI and expressed in milliseconds from
onset of pulse trigger (InTag, OsirX). A segmental scar
score was then assigned using a blinded visual interpre-
tation (score 0 to 4). The number of response prediction
rules met was determined for each patient as follows: 1)
LV lead tip placed on a dyssynchronous segment (Trs >
130msec), 2) LV lead tip placed on a viable segment
(scar score <2), 3) RV lead tip placed on a viable
segment (scar score <2). Clinical response to CRT,
defined as a >=15% reduction in LVESV by echocardio-
graphy, was correlated to the number of prediction
rules met.
Results
Forty consecutive patients were enrolled with a mean
age and ejection fraction of 67.0 ± 8.6 years and 25.6 ±
6.6%, respectively. Twenty four patients (60%) met clini-
cal response criteria with a mean reduction in LVESV of
20.5 ± 16.5% compared to a rise of 1.4 ± 6.3% in non-
responders (p<0.001). A strong correlation was seen
between the number of prediction rules met and clinical
response to CRT. In patients with 3, 2, 1 and 0 predic-
tion rules met, the response rates were 100%, 92%, 58%
and 40%, respectively (p<0.001). A strong correlation
was also seen between the number of prediction rules
and the mean reduction in LVESV [28%, 14% and 5%
reduction in those with 3, 2 and 1 rules met, respec-
tively (p=0.002)].
Conclusions
Dyssynchrony and scar characteristics of the paced myo-
cardial segments are strongly correlated with clinical
response to CRT. A simple 3-point prediction model
incorporating these variables appears to be highly pre-
dictive of response, and may be valuable for the selec-
tion of optimal pacing targets for CRT.
University of Western Ontario, London, ON, Canada
Wong et al. Journal of Cardiovascular Magnetic Resonance 2011, 13(Suppl 1):O50
http://jcmr-online.com/content/13/S1/O50
© 2011 Wong et al; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons
Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in
any medium, provided the original work is properly cited.
Published: 2 February 2011
doi:10.1186/1532-429X-13-S1-O50
Cite this article as: Wong et al.: Paced segment characteristics predict
clinical response to cardiac resynchronization therapy: results from the
multimodality imaging assessment of pacing intervention in heart
failure (MAPIT-HF) study. Journal of Cardiovascular Magnetic Resonance
2011 13(Suppl 1):O50.
Submit your next manuscript to BioMed Central
and take full advantage of: 
• Convenient online submission
• Thorough peer review
• No space constraints or color figure charges
• Immediate publication on acceptance
• Inclusion in PubMed, CAS, Scopus and Google Scholar
• Research which is freely available for redistribution
Submit your manuscript at 
www.biomedcentral.com/submit
Wong et al. Journal of Cardiovascular Magnetic Resonance 2011, 13(Suppl 1):O50
http://jcmr-online.com/content/13/S1/O50
Page 2 of 2


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Paced segment characteristics predict clinical response to cardiac resynchronization therapy: results from the multimodality imaging assessment of pacing intervention in heart failure (MAPIT-HF) study

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