Risk factors and clinical significance of elevated mitral valve gradient following valve repair for degenerative disease

OBJECTIVES: The risk factors and clinical effect of elevated mitral valve (MV) gradients after valve repair for degenerative valve disease remain insufficiently understood. METHODS: Between January 2004 and December 2015, a total of 484 patients underwent valve repair for degenerative disease. A true-sized full annuloplasty ring was implanted in all cases. We analysed the effect of preoperative and intraoperative factors on the postrepair gradient. Additionally, we explored the effect of postrepair gradients on long-term outcomes. RESULTS: On linear regression analysis, postrepair MV gradients were associated with patient age (coefficient = -0.110, standard error = 0.005, P = 0.034), body surface area (coefficient = 0.905, standard error = 0.340, P = 0.008), implanted annuloplasty ring size (coefficient = -0.181, standard error = 0.018, P < 0.001) and the use of Physio I ring (coefficient = 0.414, standard error = 0.122, P = 0.001). On multivariable analysis, postrepair MV gradient was not associated with overall survival [hazard ratio (HR) 1.034, 95% confidence interval (CI) 0.889-1.203; P = 0.66] or freedom from atrial fibrillation (HR 0.849, 95% CI 0.682-1.057; P = 0.14), but did emerge as a risk factor for MV reintervention (HR 1.378, 95% CI 1.033-1.838; P = 0.029). Two out of 11 reinterventions were performed due to MV stenosis and in both patients, high postrepair gradients were seen readily on predischarge echocardiography. CONCLUSIONS: Following valve repair for degenerative MV disease, elevated gradients occur even when true-sized annuloplasty is performed. The late clinical results of valve repair with elevated postrepair gradient are impaired and further studies are needed to explore preventive measures aimed at resolving the issue.