Impact of myocardial fibrosis in patients with symptomatic severe aortic stenosis.
BACKGROUND
In this prospective follow-up study, the effect of myocardial fibrosis on myocardial performance in symptomatic severe aortic stenosis was investigated, and the impact of fibrosis on clinical outcome after aortic valve replacement (AVR) was estimated.


RESULTS
Fifty-eight consecutive patients with isolated symptomatic severe aortic stenosis underwent extensive baseline characterization before AVR. Standard and tissue Doppler echocardiography and cardiac magnetic resonance imaging (late-enhancement imaging for replacement fibrosis) were performed at baseline and 9 months after AVR. Endomyocardial biopsies were obtained intraoperatively to determine the degree of myocardial fibrosis. Patients were analyzed according to the severity of interstitial fibrosis in cardiac biopsies (severe, n=21; mild, n=15; none, n=22). The extent of histologically determined cardiac fibrosis at baseline correlated closely with New York Heart Association functional class and markers of longitudinal systolic function (all P<0.001) but not global ejection fraction or aortic valve area. Nine months after AVR, the degree of late enhancement remained unchanged, implying that AVR failed to reduce the degree of replacement fibrosis. Patients with no fibrosis experienced a marked improvement in New York Heart Association class from 2.8+/-0.4 to 1.4+/-0.5 (P<0.001). Only parameters of longitudinal systolic function predicted this functional improvement. Four patients with severe fibrosis died during follow-up, but no patient from the other groups died.


CONCLUSIONS
Myocardial fibrosis is an important morphological substrate of postoperative clinical outcome in patients with severe aortic stenosis and was not reversible after AVR over the 9 months of follow-up examined in this study. Because markers of longitudinal systolic function appear to indicate sensitively both the severity of myocardial fibrosis and the clinical outcome, they may prove valuable for preoperative risk assessment in patients with aortic stenosis.
Weidemann
Frank
F
University Clinic of Internal Medicine I/Center for Cardiovascular Disease, University of Würzburg, 97080 Würzburg, Germany. Weidemann_f@medizin.uni-wuerzburg.de
Herrmann
Sebastian
S
Störk
Stefan
S
Niemann
Markus
M
Frantz
Stefan
S
Lange
Volkmar
V
Beer
Meinrad
M
Gattenlöhner
Stefan
S
Voelker
Wolfram
W
Ertl
Georg
G
Strotmann
Jörg M
JM
D000368:Aged; D001021:Aortic Valve / Q000473:pathology / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery*; D001706:Biopsy; D004719:Endomyocardial Fibrosis / Q000150:complications* / Q000503:physiopathology*; D005260:Female; D005355:Fibrosis; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D006352:Heart Ventricles / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D016896:Treatment Outcome