Clinical evaluation of functional mitral stenosis after mitral valve repair for degenerative disease: Potential affect on surgical strategy

Background: Mitral annuloplasty with either a partial band or complete ring is an integral part of mitral valve repair for degenerative disease. The affect of annuloplasty type on outcomes has not been well described. The objective of our study was to compare echocardiographic and functional characteristics of patients who underwent mitral repair with either a complete ring or a partial band. Methods: We evaluated 107 patients who underwent mitral repair of myxomatous degeneration at our institution by stress echocardiography, 6-minute walk testing, and short form-36 questionnaire. These assessments were performed 4.3 +/- 2.2 years following mitral repair by a single surgeon. A band was used in 65 patients (61%) and a ring in 42 patients (39%). Parametric and nonparametric tests were used in the analyses. Results: The labeled band and ring size used for repair were 30.7 +/- 2.8 mm and 30.4 +/- 2.1 mm, respectively (P - .6). The resting mean mitral gradient and valve area were 3.7 +/- 1.9 mm Hg and 2.3 +/- 0.6 cm(2) for patients who received a band and 5.8 +/- 2.6 mm Hg and 1.8 +/- 0.5 cm(2) for patients who received a ring (both P < .001). Distance traversed on 6-minute walk testing was 471 +/- 77 m in the band group and 443 +/- 107 m in the ring group (P = .1). At peak exercise, the mean mitral gradient (15.3 +/- 8.2 mm Hg vs 10.6 +/- 4.8 mm Hg; P < .001) and right ventricular systolic pressure (52.6 +/- 14.2 mm Hg vs 45.8 +/- 9.5 mm Hg; P = .004) were higher for patients who received a ring versus a band. Ring patients reported lower levels of energy (P = .02) and general health (P = .007) on short form-36 assessment. Conclusions: Annuloplasty using a complete ring may be associated with a higher mitral valve gradient at rest and at peak exercise in certain patients. These patients may also have worse quality of life. In view of these findings, we recommend careful consideration of annuloplasty type and size at the time of mitral repair of organic disease.