Progression of diffuse myocardial fibrosis assessed by cardiac magnetic resonance T₁ mapping

To evaluate long-term changes in diffuse myocardial fibrosis using cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) and T₁ mapping. Patients with chronic stable cardiomyopathy and stable clinical status (n = 52) underwent repeat CMR at a 6 month or greater follow up interval and had LGE and left ventricular (LV) T₁ mapping CMR. Diffuse myocardial fibrosis (excluding areas of focal myocardial scar) was assessed by post gadolinium myocardial T₁ times. Mean baseline age of 52 patients (66 % male) was 35 ± 19 years with a mean interval between CMR examinations of 2.0 ± 0.8 years. CMR parameters, including LV mass and ejection fraction, showed no change at follow-up CMR (p > 0.05). LVT₁ times (excluding focal scar) decreased over the study interval (from 468 ± 106 to 434 ± 82 ms, p = 0.049). 38 Patients had no visual LGE−, while 14 were LGE+. For LGE− patients, greater change in LV mass and end systolic volume index were associated with change in T₁ time (β = −2.03 ms/g/m², p = 0.035 and β = 2.1 ms/mL/m², p = 0.029, respectively). For LGE+ patients, scar size was stable between CMR1 and CMR2 (10.7 ± 13.8 and 11.5 ± 13.9 g, respectively, p = 0.32). These results suggest that diffuse myocardial fibrosis, as assessed by T₁ mapping, progresses over time in patients with chronic stable cardiomyopathy.