Myocardial structure as a determinant of pre- and postoperative ventricular function and long-term prognosis after valve replacement for aortic stenosis

Open Access
Publisher Website
Google Scholar
Abstract
Background Long-term results after aortic value replacement for aortic stenosis can be correlated to a cardiac-related pre-operative risk profile. This predictability indicates that there is a common basis in subtle or overt structural abnormalities of left ventricular myocardium. Methods and Results Forty-nine patients aged 24–82 (mean 61) years, with aortic stenosis had a full wall thickness transmural biopsy of the left ventricular antero-lateral free wall during aortic valve replacement. Echocardiography and radionuclide ventriculography were performed prior to, and 18 months (n=41) after, the operation. Postoperative follow-up to a maximum of 7·7 years was 100% complete. Pre-operatively, all patients had an increase in both the left ventricular mass index (202±67g.m−2) and the muscle cell diameter (41±8μm); other morphological data included a muscle cell nucleus volume of 752±192μm3, a muscle cell mass index of 163±54g.m−2, and a fibrous tissue mass index of 39±16g.m−2. Patients with a pre-operative episode of clinical left ventricular failure (n=19) had significantly greater morphological variables than those without. Pre-operative ejection fraction and other measures of systolic function correlated inversely with the morphological data, except for the fibrous tissue mass index; diastolic function indices correlated inversely with all the morphological variables. At the 18-month re-study, the same general picture was noted, but with an underlying strengthening, especially of the muscle cell mass index. Overall, the mass index dropped to 152±51g.m−2(PConclusion Abnormalities of the hypertrophied left ventricular muscle cell and the degree of muscle hypertrophy are, to some degree, underlying determinants of pre-operative symptomatology, pre- and postoperative ventricular function, and early and late mortality after valve replacement for aortic stenosis. Incomplete hypertrophy regression after valve replacement, being indicative of impaired results, was related to pre-operative myocardial structural abnormalities.

This publication has 0 references indexed in Scilit: