Author + information
- Received October 16, 2019
- Revision received February 27, 2020
- Accepted March 27, 2020
- Published online September 7, 2020.
- Shiro Nakamori, MDa,
- Long H. Ngo, PhDa,
- Jennifer Rodriguez, BAa,
- Ulf Neisius, MDa,
- Warren J. Manning, MDa,b and
- Reza Nezafat, PhDa,∗ ()
- aDepartment of Medicine, Cardiovascular Division, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
- bRadiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
- ↵∗Address for correspondence:
Dr. Reza Nezafat, Department of Medicine, Cardiovascular Division, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, Massachusetts 02215.
Objectives This study sought to determine whether myocardial tissue heterogeneity scanned by native T1 mapping could improve risk stratification in patients with nonischemic dilated cardiomyopathy (NICM) evaluated for primary prevention by ICD.
Background The benefit of insertable cardiac-defibrillator (ICD) as primary prevention ICD in patients with NICM remains to be fully clarified.
Methods A total of 115 NICM candidates for primary prevention and 55 healthy controls with similar distributions of age and sex were prospectively enrolled. Imaging was performed at 1.5-T using a protocol that included cine magnetic resonance for left ventricular function, late gadolinium enhancement (LGE) for focal scarring, and 5-slice native T1 mapping for diffuse fibrosis and heterogeneity. The last method was assessed by mean absolute deviation of the segmental pixel-SD from the average pixel-SD (Mad-SD). The primary endpoint was a composite of appropriate ICD therapy and sudden cardiac death.
Results During a median follow-up of 24 months, 13 patients (11%) experienced the primary endpoint. Dichotomized Mad-SD >0.24 provided a comparable outcome to the presence of LGE for the primary endpoint (annual event rate: 9.8% vs. 10.9%). The integration of Mad-SD to global native T1 showed excellent arrhythmic event-free survival (annual event rate: 0%), and high sensitivity of 85% (95% confidence interval [CI]: 55% to 98%) and moderate specificity of 72% (95% CI: 62% to 80%), with a C-statistic of 0.76 (95% CI: 0.64 to 0.87), which was comparable to the presence, location, or extent of LGE in its ability to predict arrhythmic events.
Conclusions Combined myocardium tissue heterogeneity and interstitial fibrosis assessment by native T1 mapping is an important predictor of ventricular tachycardia and ventricular fibrillation and provides additive risk stratification for primary prevention ICD in NICM patients without the need for gadolinium contrast.
- cardiac magnetic resonance
- implantable cardioverter-defibrillator
- native T1
- nonischemic dilated cardiomyopathy
- tissue heterogeneity
- ventricular fibrillation
- ventricular tachycardia
Supported by U.S. National Heart, Lung, and Blood Institute grant R01HL127015 and American Heart Association grant 15EIA22710040. Dr. Nakamori has received a scholarship from Mie University Foundation International. Dr. Nezafat has received U.S. National Institutes of Health grants 5R01HL129185, 5R01HL127015, and 1R01HL129157 and American Heart Association grant 15EIA22710040. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
The 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: Cardiovascular Imaging author instructions page.
- Received October 16, 2019.
- Revision received February 27, 2020.
- Accepted March 27, 2020.
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