Prognostic value of myocardial tissue characterization by cardiac magnetic resonance imaging using T1 mapping in nonischemic dilated cardiomyopathy: a systematic review and meta-analysis.

Aim: This study aimed to evaluate the prognostic value of T1 mapping techniques via cardiac magnetic resonance (CMR) in nonischemic dilated cardiomyopathy (NICM) patients.

Materials And Methods: PubMed and Google Scholar were searched for studies examining the prognostic value of myocardial tissue characterization via CMR imaging with T1 mapping in NICM. Major adverse cardiac events (MACE) included cardiac death, ventricular arrhythmia/sudden cardiac death (SCD) events, and heart failure events.

Results: Ten studies with a total of 3,384 patients (mean age 50.4 years; mean follow-up 28.0 months) were analyzed. The meta-analysis demonstrated that in patients with MACE, the mean extracellular volume (ECV) was greater than in those without MACE (MD: -5.40%; 95% CI: -7.91 to -2.90%; p < 0.0001). Furthermore, in patients with MACE, the native T1 value was also greater than in those without MACE (MD: - 38.87 ms; 95% CI: -59.01 to -18.74 ms; p = 0.0002). A meta-analysis showed a significant relationship between ECV and the risk of MACE (HRunadjusted: 1.19 per 1% ECV; 95% CI: 1.10-1.28; p < 0.001). After adjusting for baseline characteristics, higher ECV remained strongly associated with MACE risk (HRadjusted: 1.21 per 1% ECV; 95% CI: 1.11-1.31; p < 0.001). Higher native T1 time was also significantly associated with MACE development (HRunadjusted: 1.09 per 10 ms T1 time; 95% CI:1.02-1.15; p = 0.007). After adjustments, the association remained significant (HR adjusted: 1.01 per 10 ms T1 time; 95% CI: 1.00-1.03; p = 0.02).

Conclusions: Meta-analysis demonstrates the risk of MACE being significantly associated with a higher mean ECV fraction and native T1 time, suggesting these indices as novel risk markers to identify high-risk NICM patients.