This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Timek, T. A. Articles by Miller, D. C. Search for Related Content PubMed PubMed Citation Articles by Timek, T. A. Articles by Miller, D. C.

(Circulation. 2002;106:I-33.)
© 2002 American Heart Association, Inc.

Surgery for Valvular Heart Disease

Will a Partial Posterior Annuloplasty Ring Prevent Acute Ischemic Mitral Regurgitation?

Tomasz A. Timek, MD; Paul Dagum, MD, PhD; David T. Lai, FRACS; Frederick Tibayan, MD; David Liang, MD, PhD; George T. Daughters, MS; Motoya Hayase, MD; Neil B. Ingels, Jr, PhD; D. Craig Miller, MD

From the Department of Cardiovascular Surgery (T.A.T., P.D., D.T.L., F.T., G.T.D., N.B.I, D.C.M.), Division of Cardiovascular Medicine (D.L., M.H.), Stanford University School of Medicine, Stanford, Calif., and Laboratory of Cardiovascular Physiology and Biophysics, Research Institute of the Palo Alto Medical Foundation, Palo Alto, Calif. (G.T.D., N.B.I.).

Correspondence to D. Craig Miller, MD, Falk Cardiovascular Research Center, Stanford University School of Medicine, Stanford, CA 94305-5407. E-mail dcm{at}stanford.edu

Background Acute posterolateral ischemia in sheep results in ischemic mitral regurgitation (IMR). While complete ring annuloplasty prevents acute IMR, partial annuloplasty rings may offer a more physiologic repair, but are untested in animal models of IMR.

Methods Radiopaque markers were placed on the LV, mitral annulus (MA), and leaflets in 13 sheep. Seven sheep served as controls, and 6 had a St. Jude Tailor partial flexible ring implanted (29 mm in 5, 31 mm in 1). After 8±1 day, the animals were studied with biplane videofluoroscopy and echocardiography before and during acute posterolateral LV ischemia (balloon occlusion of circumflex artery). Mitral annular area (MAA), septal-lateral annular diameter (SL), annular perimeters, and leaflet edge separation were calculated from 3-D marker coordinates.

Results The average degree of mitral regurgitation increased from 0.0±0.0 to 2.1±0.7 (P=0.0006) in the control group during acute ischemia but remained unchanged in the Tailor group (0.1±0.2 for both conditions). The change in MAA throughout the cardiac cycle before ischemia was 17±4% in control animals, but only 5±2% (P=0.0002) in the Tailor ring group. Unlike the control animals, there was no increase in MAA (5.4±0.8 and 5.5±0.7 cm², respectively; p=NS) nor dilatation of the muscular annulus (6.2±0.3 and 6.2±0.4, respectively; p=NS) during ischemia with the Tailor ring. Mitral SL dimension increased slightly with ischemia (2.3±0.2 versus 2.2±0.2 cm, P=0.03). Although posterior leaflet motion was limited, as observed with complete rings, normal annular flexion was maintained with the Tailor ring before and during acute ischemia.

Conclusions The Tailor partial annuloplasty ring prevented acute IMR probably by limiting SL diameter dilatation during acute ischemia. In this animal model of acute IMR, a partial, flexible posterior annuloplasty ring is as effective as a complete ring.

Key Words: ischemia • mitral valve • regurgitation • valvuloplasty