Prognostic value of myocardial oedema measured by T2 mapping in non-ischaemic dilated cardiomyopathy

Introduction There is an increasing recognition in myocardial inflammation and oedema in dilated cardiomyopathy (DCM). T2 mapping is an accurate and sensitive parameter to myocardial oedema. However, the prognostic value of myocardial oedema measured by T2 mapping in patients with non-ischaemic DCM remains unclear. Purpose To evaluate the prognostic value of myocardial oedema measured by T2 mapping in non-ischaemic DCM. Methods Patients with non-ischaemic DCM who underwent cardiovascular magnetic resonance imaging between September 2013 and November 2022 were prospectively enrolled. Myocardial oedema was quantitatively measured by T2 mapping in left ventricular mid-myocardium. The primary endpoint included cardiovascular death and heart transplantation. Cox regression analyses and Kaplan-Meier survival analysis were performed to identify the association between variables and outcomes. Results There were 1128 participants (mean age, 48 years ± 14 [standard deviation]; 767 men) evaluated. During the median follow-up of 52.7 months (interquartile range: 37.3–76.2 months), 227 (20.1%) patients reached the primary endpoints. T2 mapping were higher in participants with primary endpoint (43.2 ± 3.5 ms vs. 45.0 ± 4.4 ms, P < 0.001). Survival analysis demonstrated that patients with higher T2 value were associated with significantly higher risk of primary outcome (Log-rank P <0.001). In multivariate Cox regression analysis, T2 was an independent predictor for primary endpoint (hazard ratio [HR] per 2% increase, 1.19 [95% CI: 1.10–1.29; P < 0.001]). Specifically, higher T2 values were also independently associated with heart failure death and sudden cardiac death. Among patients with late gadolinium enhancement [LGE(+)], left ventricular ejection fraction (LVEF) ≤ 30%, or extracellular volume fraction (ECV) > 30%, those with T2 > 45.3 ms had a higher risk of developing adverse outcomes (P < 0.001). Conclusions Myocardial oedema measured by T2 mapping is an independent predictor of adverse clinical outcome in non-ischaemic dilated cardiomyopathy.