Background:

Myocardial fibrosis, identified by late gadolinium enhancement cardiovascular magnetic resonance, predicts outcomes in chronic heart failure (HF). Its prognostic significance in new-onset HF and reduced left ventricular ejection fraction (LVEF) is unclear. We investigated whether the pattern and extent of fibrosis predict survival in new-onset HF and reduced LVEF of initially uncertain pathogenesis.
Methods and Results:

Of 120 consecutive patients with new-onset (<6 months) HF and reduced LVEF, 31 (26%) had infarct fibrosis, 25 (21%) had midwall fibrosis, and 64 (53%) had no fibrosis. During median follow-up of 8.9 years, 33 (28%) patients died. Patients with infarct fibrosis (hazard ratios [HR], 3.32; 95% CI, 1.46–7.58; P=0.004) or midwall fibrosis (HR, 2.99; 95% CI, 1.24–7.19; P=0.014) were more likely to die compared with those without fibrosis. On multivariable analysis, the pattern and extent of fibrosis were both associated with all-cause mortality (by fibrosis pattern: infarct: HR, 2.60; 95% CI, 1.08–6.27; P=0.033; midwall: HR, 2.64; 95% CI, 1.08–6.47; P=0.034; by fibrosis extent per 1%: HR, 1.07; 95% CI, 1.03–1.12; P<0.001). Fibrosis pattern also predicted composites of cardiovascular mortality or aborted sudden cardiac death (infarct: HR, 3.45; 95% CI, 1.20–9.90; P=0.022; midwall: HR, 6.59; 95% CI, 2.26–19.22; P<0.001), and all-cause mortality, HF hospitalization, or aborted sudden cardiac death (infarct: HR, 2.69; 95% CI, 1.26–5.76; P=0.011; midwall fibrosis: HR, 2.97; 95% CI, 1.37–6.45; P=0.006). Addition of fibrosis pattern to LVEF improved risk prediction for all-cause mortality (LVEF versus LVEF+fibrosis C statistic: 0.66 versus 0.71; P=0.033). Importantly, the absence of fibrosis heralded a favorable prognosis with an 85% survival rate over the duration of follow-up.
Conclusions:

The pattern and extent of myocardial fibrosis predict adverse outcomes in new-onset HF and reduced LVEF. In contrast, the absence of fibrosis portends a durable warranty period with a low incidence of adverse events. These findings support a role for late gadolinium enhancement cardiovascular magnetic resonance in the early risk stratification of patients with HF of uncertain pathogenesis.