Author + information
- Received October 31, 2013
- Revision received January 2, 2014
- Accepted February 4, 2014
- Published online April 29, 2014.
- Kenneth C. Bilchick, MD, MS∗∗ (, )
- Sujith Kuruvilla, MD∗,
- Yasmin S. Hamirani, MD∗,
- Raghav Ramachandran, MS†,
- Samantha A. Clarke, BS†,
- Katherine M. Parker, PhD†,
- George J. Stukenborg, PhD, MA‡,
- Pamela Mason, MD∗,
- John D. Ferguson, MBChB, MD∗,
- J. Randall Moorman, MD∗,
- Rohit Malhotra, MD∗,
- J. Michael Mangrum, MD∗,
- Andrew E. Darby, MD∗,
- John DiMarco, MD, PhD∗,
- Jeffrey W. Holmes, MD, PhD∗,†,
- Michael Salerno, MD, PhD∗,†,§,
- Christopher M. Kramer, MD∗,§ and
- Frederick H. Epstein, PhD†,§
- ∗Department of Medicine, Cardiovascular Division, University of Virginia Health System, Charlottesville, Virginia
- †Department of Biomedical Engineering, University of Virginia Health System, Charlottesville, Virginia
- ‡Department of Public Health Sciences, University of Virginia Health System, Charlottesville, Virginia
- §Department of Radiology and Medical Imaging, University of Virginia Health System, Charlottesville, Virginia
- ↵∗Reprint requests and correspondence:
Dr. Kenneth C. Bilchick, Department of Medicine, Cardiology/Electrophysiology, University of Virginia Health System, P.O. Box 800158, Charlottesville, Virginia 22908.
Objectives Using cardiac magnetic resonance (CMR), we sought to evaluate the relative influences of mechanical, electrical, and scar properties at the left ventricular lead position (LVLP) on cardiac resynchronization therapy (CRT) response and clinical events.
Background CMR cine displacement encoding with stimulated echoes (DENSE) provides high-quality strain for overall dyssynchrony (circumferential uniformity ratio estimate [CURE] 0 to 1) and timing of onset of circumferential contraction at the LVLP. CMR DENSE, late gadolinium enhancement, and electrical timing together could improve upon other imaging modalities for evaluating the optimal LVLP.
Methods Patients had complete CMR studies and echocardiography before CRT. CRT response was defined as a 15% reduction in left ventricular end-systolic volume. Electrical activation was assessed as the time from QRS onset to LVLP electrogram (QLV). Patients were then followed for clinical events.
Results In 75 patients, multivariable logistic modeling accurately identified the 40 patients (53%) with CRT response (area under the curve: 0.95 [p < 0.0001]) based on CURE (odds ratio [OR]: 2.59/0.1 decrease), delayed circumferential contraction onset at LVLP (OR: 6.55), absent LVLP scar (OR: 14.9), and QLV (OR: 1.31/10 ms increase). The 33% of patients with CURE <0.70, absence of LVLP scar, and delayed LVLP contraction onset had a 100% response rate, whereas those with CURE ≥0.70 had a 0% CRT response rate and a 12-fold increased risk of death; the remaining patients had a mixed response profile.
Conclusions Mechanical, electrical, and scar properties at the LVLP together with CMR mechanical dyssynchrony are strongly associated with echocardiographic CRT response and clinical events after CRT. Modeling these findings holds promise for improving CRT outcomes.
- cardiac magnetic resonance
- cardiac resynchronization therapy
- heart failure
- myocardial infarction
- ventricular tachycardia
Dr. Bilchick has received support from the National Institutes of Health (NIH) (K23 grant HL094761); and has served as a consultant to Biosense Webster. Dr. Parker is an employee of Sorin Group USA, Inc. Dr. Mason has received grant support from Medtronic and Boston Scientific; and has received support from St. Jude Medical and Johnson & Johnson. Dr. Ferguson has received consulting support from Biosense Webster and St. Jude Medical; and has received honoraria from Medtronic. Dr. Malhotra has received grant support from Medtronic and Boston Scientific. Dr. Mangrum has received grant and consulting support from St. Jude Medical; and has received research funding from St. Jude Medical, Hansen Medical, EndoSense, CardioFocus, and Boston Scientific. Dr. Darby has served as a consultant for Biosense Webster; has received speaking honoraria from Medtronic; and has received research support from Boston Scientific. Dr. DiMarco has received consulting support from Medtronic, St. Jude Medical, and Boston Scientific. Dr. Holmes has received support from the NIH (R01 grant HL085160). Dr. Kramer has received grant support from Siemens Healthcare; and has served as a consultant to Synarc and St. Jude Medical. Dr. Epstein has received support from the NIH (R01 grant EB001763); and has received grant support from Siemens Healthcare. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received October 31, 2013.
- Revision received January 2, 2014.
- Accepted February 4, 2014.
- American College of Cardiology Foundation