Late Gadolinium Enhancement–Dispersion Mapping: A New Magnetic Resonance Imaging Technique to Assess Prognosis in Patients With Hypertrophic Cardiomyopathy and Low-Intermediate 5-Year Risk of Sudden Death

• Published in: Circulation. Cardiovascular imaging Vol. 13; no. 6; p. e010489
• Main Authors: Aquaro, Giovanni Donato, Grigoratos, Chrysanthos, Bracco, Antonio, Proclemer, Alberto, Todiere, Giancarlo, Martini, Nicola, Habtemicael, Yacob Ghebru, Carerj, Scipione, Sinagra, Gianfranco, Di Bella, Gianluca
• Format: Journal Article
• Language: English
• Published: American Heart Association, Inc 01-06-2020
• ISSN: 1942-0080; 1941-9651; 1942-0080
• DOI: 10.1161/CIRCIMAGING.120.010489

Background:
Late gadolinium enhancement (LGE) is an important prognostic marker in hypertrophic cardiomyopathy and an extent >15% it is associated with high risk of sudden cardiac death. We proposed a novel method, the LGE-dispersion mapping, to assess heterogeneity of scar, and evaluated its prognostic role in patients with hypertrophic cardiomyopathy.
Methods:
One hundred eighty-three patients with hypertrophic cardiomyopathy and a low- or intermediate 5-year risk of sudden cardiac death underwent cardiac magnetic resonance imaging. A parametric map was generated from each LGE image. A score from 0 to 8 was assigned at every pixel of these maps, indicating the number of the surrounding pixels having different quality (nonenhancement, mild-enhancement, or hyperenhancement) from the central pixel. The Global Dispersion Score (GDS) was calculated as the average score of all the pixels of the images.
Results:
During a median follow-up time of 6 (25th–75th, 4–10) years, 22 patients had hard cardiac events (sudden cardiac death, appropriate implantable cardioverter-defibrillator therapy, resuscitated cardiac arrest, and sustained ventricular tachycardia). Kaplan-Meier analysis showed that patients with GDS>0.86 had worse prognosis than those with lower GDS (
P
<0.0001). GDS>0.86 was the only independent predictor of cardiac events (hazard ratio, 9.9 [95% CI, 2.9–34.6],
P
=0.0003). When compared with LGE extent >15%, GDS improved the classification of risk in these patients (net reclassification improvement, 0.39 [95% CI, 0.11–0.72],
P
<0.019).
Conclusions:
LGE-dispersion mapping is a marker of scar heterogeneity and provides a better risk stratification than LGE presence and its extent in patients with hypertrophic cardiomyopathy and a low-intermediate 5-year risk of sudden cardiac death.