The Incremental Prognostic Value of Myocardial Fibrosis in Patients With Non-Ischemic Cardiomyopathy Without Congestive Heart Failure
Background—We conducted a prospective longitudinal study to investigate the yet unknown clinical significance of myocardial fibrosis in non-ischemic cardiomyopathy(NICM) patients without history of congestive heart failure(CHF).
Methods and Results—At 3 tertiary referral Centers, 228 NICM patients without history of CHF were studied with cardiovascular magnetic resonance(CMR) for late gadolinium enhancement(LGE) detection and quantification, and prospectively followed-up for a median of 23 months. The end-point was a composite of cardiac death, onset of CHF and aborted sudden cardiac death(SCD). LGE was detected in 61(27%) patients. Thirty-one of 61(51%) patients with LGE reached combined end-point compared to 18 of 167(11%) patients without LGE (HR:5.10[2.78-9.36],P<0.001). Patients with LGE had greater risk of developing CHF than patients without LGE (HR:5.23[2.61-10.50],P<0.001) and higher rate of aborted SCD (HR:8.31[1.66-41.55],P=0.010). Multivariate analysis showed that LGE was associated with high likelihood of composite end-point independently of other prognostic determinants, including age, duration of cardiomyopathy and left ventricular (LV) volumes, mass and ejection-fraction (HR:4.02[2.08-7.76],P<0.001). Improvement chi-squared analysis disclosed that LGE addition to models including clinical data alone or in combination with parameters of LV remodeling and function yielded an improvement in outcome prediction (P<0.001). Addition of LGE to age and LV ejection-fraction improved risk stratification for composite end-point (net reclassification improvement [NRI]:29.6%) and onset of CHF(NRI:25.4%, both P<0.001).
Conclusions—In NICM patients without history of CHF, myocardial fibrosis is a strong and independent predictor of outcome providing incremental prognostic information and improvement in risk stratification beyond clinical data and degree of LV dysfunction.
- Received September 26, 2013.
- Accepted March 10, 2014.