Predictors of mitral valve hemodynamics after mitral valve repair for degenerative mitral regurgitation: a subanalysis of the CAMRA randomized trial

Abstract

Abstract Introduction Intra-operative predictors of mid-to-late mitral valve dysfunction after surgical repair of mitral regurgitation (MR) caused by prolapse remain poorly characterized. This study aims to evaluate the effect of annuloplasty prosthesis size on post-operative MV hemodynamics at rest and during exercise, and to identify perioperative predictors of MV dysfunction. Methods 104 patients were randomly assigned to resection and preservation for surgical treatment of posterior leaflet prolapse in the Canadian Mitral Research Alliance CardioLink-2 study. Echocardiograms were performed at baseline and 1 year postoperatively. Intraoperative TEE was performed to assess immediate MV gradients. Exercise TTE was performed 1 year after repair. Linear regression analysis was used to identify associations between MV indices (rest and peak exercise gradients) at 12 months, and perioperative echocardiographic and clinical factors. Results Mean age of participants was 65±10 years, and 83% were male. Larger annuloplasty size was associated with lower transmitral gradients at rest and during peak exercise. In multivariable analysis, annuloplasty size ≥34mm was associated with lower mean and peak rest and exercise gradients at 12 months, after adjustment for repair type, age, sex, and BSA (p<0.001). Higher pre-operative pulmonary artery pressures were associated with reduced functional capacity post-operatively. Intra-operative TEE gradients predict resting and exercise MV hemodynamics at 1 year. Conclusion Annuloplasty size ≥34mm is associated with improved MV hemodynamics at rest and during peak exercise 1 year post MV repair. MV repair prior to onset of pulmonary hypertension confers favourable post operative functional capacity. Finally, intra-operative TEE can be used to identify patients at risk of mitral valve dysfunction within 1 year of repair. Funding Acknowledgement Type of funding sources: Other. Main funding source(s): The Heart and StrokeFoundation of Ontario (GIA 16-00014666)