Prevalence of Myocardial Fibrosis Patterns in Patients with Systolic Dysfunction: Prognostic Significance for the Prediction of Sudden Cardiac Arrest or Appropriate ICD Therapy
Background—Late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) is increasingly performed in patients with systolic dysfunction. Numerous patterns of fibrosis are commonly reported among this population. However, the relative prevalence and prognostic significance of these findings remains uncertain.
Methods and Results—Three hundred and eighteen consecutive patients referred for LGE-CMR and a left ventricular ejection fraction (LVEF) <55% were followed for the primary endpoint of sudden cardiac arrest (SCA) or appropriate implantable cardiac defibrillator (ICD) therapy. LGE images were blindly interpreted for the presence of six distinct pattern(s) of myocardial fibrosis in addition to signal threshold-based quantification of total fibrosis volume. The mean age and LVEF of participants was 62.0±12.9 years and 32.6±11.9% respectively. Any pattern of myocardial fibrosis was seen in 248 patients (78%) with ≥2 patterns present in 25% of patients. During follow up (median of 467 days), 49 patients (15%) had suffered a primary outcome. Following adjustment for LVEF, Cardiomyopathy etiology, and Total fibrosis volume; the presence of a mid-wall straie pattern of fibrosis was an independent predictor of SCA or Appropriate ICD therapy with a HR of 2.4 (95%CI 1.2-4.6, p=0.01), this finding present in 30% of non-ischemic and 15% of ischemic cardiomyopathy patients. Event free survival was significantly lower among those with mid-wall striae, particularly among those with an LVEF >35% (40% versus 6%, p=0.005).
Conclusions—Patients with systolic dysfunction frequently demonstrate multiple patterns of myocardial fibrosis. Of these, a mid-wall striae pattern of fibrosis is the strongest independent predictor of SCA or Appropriate ICD therapy.
- Received November 5, 2013.
- Accepted May 30, 2014.