NONPREDICTIVE VALUE OF FIBROSIS IN DILATED CARDIOMYOPATHY TREATED WITH METOPROLOL

Citation
G. Sinagra et al., NONPREDICTIVE VALUE OF FIBROSIS IN DILATED CARDIOMYOPATHY TREATED WITH METOPROLOL, Cardiovascular pathology, 5(1), 1996, pp. 21-28
Citations number
41
Categorie Soggetti
Pathology,"Cardiac & Cardiovascular System
Journal title
ISSN journal
10548807
Volume
5
Issue
1
Year of publication
1996
Pages
21 - 28
Database
ISI
SICI code
1054-8807(1996)5:1<21:NVOFID>2.0.ZU;2-F
Abstract
Therapy with beta-adrenergic blocking agents has been advocated as a p otential useful approach in heart failure. Recent studies suggest that histologic parameters may be helpful in assessing the effectiveness o f beta-blocker treatment in dilated cardiomyopathy (DCM). In order to predict the response to beta-blockers in DCM, fibrous tissue was evalu ated at endomyocardial biopsy (EMB) in 45 patients (pts) with a mean l eft ventricular ejection fraction of 0.28 +/- 0.07, who were successiv ely long-term treated with metoprolol (M) (mean dosage 138 +/- 26 mg/d ie). EMB was performed from left (n = 32) or right (n = 13) ventricle by means of a King's bioptome or the Cordis adaptation of this instrum ent. Quantification of fibrous tissue was performed at 9 x magnificati on and with a computerized morphometric system. Qualitative evaluation at light microscopy distinguished four types of fibrosis: pericellula r, perivascular, focal, and endocardial. Volume fraction of fibrous ti ssue ranged from 1.3 to 35.5% (mean 12.1 +/- 9.3%) and was not signifi cantly correlated with any clinical variable considered. After 24 +/- 12 months of treatment, 25 pts were considered improved (group A), whe reas the remaining 20 pts were considered not improved (group B), acco rding to criteria based on ejection fraction, left ventricular end-dia stolic diameter, filling pattern at Doppler-Echocardiography, cardioth oracic ratio, NYHA functional class, and exercise duration at ergometr ic test. Volume fraction of fibrous tissue did not differ significantl y between the two groups (group A = 12.1 +/- 9.1%; group B = 11.3 +/- 9.6%; p = NS). Dominant pericellular type of fibrosis was equally dist ributed between the two groups (group A = 9/25 pts, 36%; group B = 10/ 20 pts, 50%), whereas a perivascular and/or focal replacement fibrosis was more frequent in group A (group A = 10/20 pts, 50%; group B = 2/2 0 pts, 10%; p = .05, OR 5.55 at univariate analysis). At multivariate analysis mean aortic blood pressure was the only variable discriminati ng the two groups; the type of fibrosis, although not statistically si gnificant, maintained a high value of odds-ratio (5.23). In conclusion , extent of total fibrosis assessed by EMB may range widely in patient s with DCM, is not correlated with the most important clinical variabl es, and is not predictive of long-term response to beta-blocker treatm ent. Otherwise, prevalent perivascular and/or focal replacement fibros is could be associated with a higher probability of improvement after long-term beta-blocker treatment.