Myocardial fibrosis and ventricular remodeling in severe chronic aortic regurgitation.
BACKGROUND
Significant symptomatic chronic aortic regurgitation (AR) leads to considerable left ventricular remodeling at the expense of myocyte hypertrophy and extracellular matrix remodeling. The relevance of interstitial fibrosis concentration in these patients is unknown. We analyzed the degree of fibrosis in the left ventricle (LV) in symptomatic patients with AR submitted to surgical treatment, and its relationship with functional and anatomical characteristics.


OBJECTIVE
To evaluate myocardial fibrosis in chronic severe aortic regurgitation.


METHODS
Twenty-eight patients with chronic symptomatic AR (16 with normal LV function and 12 with LV dysfunction) were selected and assessed pre- and postoperatively by echocardiography. Functional capacity was measured using maximal oxygen consumption (VO2max) through the cardiopulmonary test. Myocardial fibrosis volume fraction (MFV) was quantified through endomyocardial biopsy performed in all patients during surgery. We compared the histopathologic results with a nine-patient control group.


RESULTS
The mean age was 39 +/- 12 years, 75% of the patients were male, and the rheumatic etiology accounted for 84% of the cases. Twenty-five patients remained in FC l and ll at the end of the study, and there was a significant reduction of the LV diameters between the preoperative and late postoperative timepoints. Three deaths occurred but they were not related to postoperative ventricular dysfunction. The parameters of the cardiopulmonary test were similar between pre- and postoperative timepoints. MFV in patients with AR was significantly higher than in the control group (3.47 +/- 1.9% vs 0.82 +/- 0.96%, respectively, p=0.001). There was no statistical correlation among LV fibrosis and LV diameters, LVEF and MVO2.


CONCLUSIONS
In patients with significant symptomatic AR, the presence of limited myocardial fibrosis was not associated with clinical, echocardiographic or functional complications.
Elias
Nelson
N
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
Tarasoutchi
Flávio
F
Spina
Guilherme Sobreira
GS
Sampaio
Roney O
RO
Pomerantzeff
Pablo M A
PM
Laurindo
Francisco Rafael
FR
Grinberg
Max
M
D000328:Adult; D001022:Aortic Valve Insufficiency / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D002908:Chronic Disease; D003094:Collagen / Q000378:metabolism; D004719:Endomyocardial Fibrosis / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D011182:Postoperative Care; D011300:Preoperative Care; D013318:Stroke Volume / Q000502:physiology; D020257:Ventricular Remodeling / Q000502:physiology*
D003094:Collagen