Prognostic Significance of Delayed-Enhancement Magnetic Resonance Imaging

Abstract

Background— Left ventricular ejection fraction is a powerful independent predictor of survival in cardiac patients, especially those with coronary artery disease. Delayed-enhancement magnetic resonance imaging (DE-MRI) can accurately identify irreversible myocardial injury with high spatial and contrast resolution. To date, relatively limited data are available on the prognostic value of DE-MRI, so we sought to determine whether DE-MRI findings independently predict survival. Methods and Results— The medical records of 857 consecutive patients who had complete cine and DE-MRI evaluation at a tertiary care center were reviewed regardless of whether the patients had coronary artery disease. The presence and extent of myocardial scar were evaluated qualitatively by a single experienced observer. The primary, composite end point was all-cause mortality or cardiac transplantation. Survival data were obtained from the Social Security Death Index. The median follow-up was 4.4 years; 252 patients (29%) reached one of the end points. Independent predictors of mortality or transplantation included congestive heart failure, ejection fraction, and age ( P <0.0001 for each), as well as scar index (hazard ratio, 1.26; 95% confidence interval, 1.02 to 1.55; P =0.033). Similarly, in subsets of patients with or without coronary artery disease, scar index also independently predicted mortality or transplantation (hazard ratio, 1.33; 95% confidence interval, 1.05 to 1.68; P =0.018; and hazard ratio, 5.65; 95% confidence interval, 1.74 to 18.3; P =0.004, respectively). Cox regression analysis showed worse outcome in patients with any DE in addition to depressed left ventricular ejection fraction (<50%). Conclusion— The degree of DE detected by DE-MRI appears to strongly predict all-cause mortality or cardiac transplantation after adjustment for traditional, well-known prognosticators.