Predictive Value of the Extent of Fibrosis on the Progression of Dilated Cardiomyopathy
K Osborn, W Muzaffar, SH Litovsky. University of Alabama at Birmingham, Birmingham, AL
Background: Dilated cardiomyopathy is a primary myocardial disease characterized by dilatation and impaired ventricular contraction. It has no typical histopathologic features although fibrosis, ranging from mild to extensive is a constant feature. It is unknown whether extensive fibrosis predicts a worst prognosis in patients with dilated cardiomyopathy. The objective of this project is to compare the progression of disease in patients with the highest degree of myocardial fibrosis with those with the lowest extent of fibrosis.
Design: Thirty consecutive adult patients that underwent allograft cardiac transplantation between 2004 and 2008 at the University of Alabama at Birmingham for idiopathic dilated cardiomyopathy were included. Morphometry to quantify fibrosis was performed on picrosirius red stained slides (5 per patient) of ventricular muscle. The total fibrosis of the five sections was expressed as percentage of the myocardial mass. The 15 patients with the highest percentage of fibrosis were contrasted with the 15 patients with the lowest extent of fibrosis in terms of demographics, duration of the heart failure from beginning of symptoms until transplantation, association with diabetes and renal failure, severe mitral regurgitation and need for defibrillator placement.
Results: Patients in the upper half degree of fibrosis (17.7 ±3.9%) had statistical non significant differences with the lower half (9.6% ± 3.5%) with regards to age at transplantation (44.1 ±10.6 vs 50.7±12.9 years), gender (10 males vs 9 males) or race (7/15 whites vs 9/15 whites). Patients in the higher fibrosis group had a longer time course between beginning of symptoms and transplantation (8.9± 5.6 vs 6.2± 6.4 years). Moreover, 13/15 patients in the higher fibrosis group had a heart failure history longer than 5 years while only 7 out of 15 in the lower fibrosis group. Patients in the higher fibrosis group had more prevalence of diabetes (5/15 vs 1/15), and a trend toward less mitral regurgitation (8/15 vs 10/15). 13/15 patients in both groups had a cardioverter-defibrillator implanted.
Conclusions: The main finding is that the highest degree of fibrosis was associated with a longer disease course, suggesting that fibrosis is not associated with a faster course of heart failure. Cardioverter defibrillators were as likely to be implanted in either group. Patients with diabetes were more prevalent in the higher fibrosis group but mitral regurgitation in the lower group, in keeping with the known extracellular matrix degradation in mitral regurgitation.
Wednesday, March 24, 2010 1:00 PM
Poster Session VI # 29, Wednesday Afternoon