Continued Global Left Ventricular Remodeling Is Not the Sole Mechanism Responsible for the Late Recurrence of Ischemic Mitral Regurgitation after Restrictive Annuloplasty
published online 08 October 2009.
Background
Recurrence of ischemic mitral regurgitation (MR) late after mitral valve annuloplasty (MVA) is generally believed to be due to continued left ventricular (LV) remodeling. The aim of this study was to determine if other mechanisms could be involved in MR recurrence.
Methods and Results
Preoperative (10 ± 11 days), early postoperative (6 ± 4 days), and late postoperative (1.5 ± 0.6 years) transthoracic echocardiograms of 26 patients (68 ± 7 years, 23 male [88%]) who underwent restrictive MVA and coronary artery bypass graft surgery were reviewed. Mitral valve geometry and MR severity were assessed using anterior leaflet and posterior leaflet angles and the anterior leaflet concavity area, defined as the area enclosed between the AL and a line connecting the tip of the leaflet and its basal insertion at the annulus. Recurrent MR (vena contracta > 3 mm) was observed in 10 patients (38.5%). Among the 10 patients with recurrent MR, 5 had significant late postoperative increase in LV end-systolic (preoperative: 66 ± 27 mL; early postoperative: 61 ± 11 mL; late postoperative: 89 ± 30 mL, P = .04) and end-diastolic (preoperative: 122 ± 39 mL; early postoperative: 108 ± 22 mL; late postoperative: 139 ± 39 mL, P = .04) volumes and PL angle (early postoperative: 65 ± 12 degrees; late postoperative: 77 ± 8 degrees, P = .04), suggesting that recurrent MR is related to continued adverse LV remodeling and ensuing worsening of leaflet tethering. However, in the remaining 5 patients with recurrent MR, there was no significant change in LV end-systolic and end-diastolic volumes, but there was a significant increase in anterior leaflet concavity area (early postoperative: 6 ± 11 mm2; late postoperative: 50 ± 3 mm2, P = .012).
Conclusion
Although recurrent MR is often associated with continued adverse LV remodeling after restrictive MVA, this mechanism fails to explain all recurrences. In the absence of LV dilatation, recurrent MR might be explained by localized LV remodeling in the vicinity of papillary muscles resulting in increased AL tethering at the bending point.
Institut de Cardiologie de Québec, Hôpital Laval, Department of Cardiology, Faculty of Medecine, Laval University, Québec City, Québec, Canada
Reprint requests: Mario Sénéchal, MD, FRCPC, Institut de Cardiologie de Québec, Hôpital Laval, Department of Cardiology, 2725 Chemin Sainte-Foy, Quebec, Quebec, Canada, G1 V 4G5
Disclosure: None.
This work was supported by a grant from the Institut de Cardiologie de Québec, Hôpital Laval, Quebec, Canada (Dr Sénéchal) and the Canadian Institutes of Health Research (MOP 67123), Ottawa, Canada. Dr Pibarot holds the Canada Research Chair in Valvular Heart Diseases, Canadian Institutes of Health Research, Ottawa, Ontario, Canada.
ABSTRACT