Comparing CMR Mapping Methods and Myocardial Patterns Toward Heart Failure Outcomes in Nonischemic Dilated Cardiomyopathy.
OBJECTIVES
In patients with nonischemic dilated cardiomyopathy (NIDCM), native T1, partition coefficient (λGd), and extracellular volume fraction (ECV) mapping may offer prognostic values beyond late gadolinium enhancement (LGE), by scaling the range of myocardial changes.


BACKGROUND
In patients with NIDCM, LGE is seen in 30% of patients and it indicates adverse prognosis.


METHODS
The study mapped 6 anatomical locations using all 4 cardiac magnetic resonance (CMR) tissue-characterizing methods and associated with outcome. The authors performed T1 mapping of the myocardium and the blood pool, before and serially after contrast injection, using a Look-Locker cine gradient-echo technique to obtain T1 and the corresponding reciprocal R1 values. λGd values were derived from the slopes of the least-squares regression lines for myocardial versus blood R1, then adjusted to serum hematocrit to yield ECV.


RESULTS
Consecutive 240 NIDCM patients (49 ± 16 years of age; 38% women) underwent CMR for cardiac function, LGE, native T1, λGd, and ECV. After a median of 3.8 years, 36 (15%) experienced major adverse cardiac events (MACE), including 22 heart failure hospitalizations and 14 deaths. Nonischemic LGE was detected in 34%, whereas ECV was elevated (≥1 location) in 58%. Comparing the 4 methods, mean ECV and λGd both demonstrated strong association with MACE (both p < 0.001). In contrast to native T1 and LGE, ECV values from all 6 locations were associated with MACE and death, with the anteroseptum being the most significant (p < 0.0001). The number of abnormal ECV locations correlated linearly with annual MACE rates (p = 0.0003). Mean ECV was the only predictor to enter a prognostic model that contained age, sex, New York Heart Association functional class, and left ventricular ejection fraction. For every 10% increase, mean ECV portended to a 2.8-fold adjusted increase risk to MACE (p < 0.001).


CONCLUSIONS
In this study of patients with NIDCM, mapping the myocardial extent of abnormality using ECV offers prognostication toward heart failure outcomes incremental to LGE or native T1 mapping.
['Vita|Tomas|T|', 'Gräni|Christoph|C|', 'Abbasi|Siddique A|SA|', 'Neilan|Tomas G|TG|', 'Rowin|Ethan|E|', 'Kaneko|Kyoichi|K|', 'Coelho-Filho|Otavio|O|', 'Watanabe|Eri|E|', 'Mongeon|Francois-Pierre|FP|', 'Farhad|Hoshang|H|', 'Rassi|Carlos Henrique|CH|', 'Choi|Yuna L|YL|', 'Cheng|Kathleen|K|', 'Givertz|Michael M|MM|', 'Blankstein|Ron|R|', 'Steigner|Michael|M|', 'Aghayev|Ayaz|A|', 'Jerosch-Herold|Michael|M|', 'Kwong|Raymond Y|RY|']
D000328:Adult D000368:Aged D002311:Cardiomyopathy, Dilated D003287:Contrast Media D018450:Disease Progression D005260:Female D019786:Gadolinium DTPA D006333:Heart Failure D006801:Humans D019028:Magnetic Resonance Imaging, Cine D008297:Male D008875:Middle Aged D009206:Myocardium D011237:Predictive Value of Tests D011379:Prognosis D012307:Risk Factors D013318:Stroke Volume D016277:Ventricular Function, Left
dilated cardiomyopathy NIDCM native T1 partition coefficient ECV