Effect of aortic valve replacement, for aortic stenosis, on concomitant mitral valve regurgitation

Abstract

Objective: Mild-to-moderate mitral regurgitation (MR) often coexists with severe aortic stenosis and has been reported to be presented in up to 2/3 patients requiring aortic valve replacement (AVR). MR in patients with aortic stenosis is often functional in nature although organic mitral disease may coexist. Increased afterload and left ventricular remodeling have been implicated to explain the functional MR in patients with aortic valve stenosis. Furthermore, remodeling observed after AVR may impact the outcome of MR postoperatively. However, the clinical outcome of persistent MR after AVR is uninvestigated. On the other hand, concomitant replacement of the aortic and mitral valves is associated with an increased morbidity and mortality compared to an isolated AVR. This study aims to assess the change in MR severity following AVR for severe AS and to determine the factors associated with the MR improvement. Material and Methods: The clinical and surgical characteristics were compared in a cohort of 149 consecutive patients who underwent isolated AVR in Aleppo University Hospital for cardiac surgery. Results: Non-severe functional mitral valve regurgitation was detected prior to surgery in 25.5% of the patients. These patients were older (p = 0.007), more often had ventricular dysfunction (p = 0.02) and pulmonary hypertension (p = 0.04), and had been admitted more frequently for heart failure (0.008), with fewer of them conserving sinus rhythm (p = 0.003). In addition, the pre-surgery existence of MR was associated with greater morbidity and mortality (5.2% vs. 3.7%; p = 0.025). The MR disappeared or improved prior to hospital discharge in 56.2% and 15.6%, respectively. Independent factors predicting this improvement were the presence of coronary lesions (OR 3.74, p = 0.03), and the absence of diabetes (OR 0.28, p = 0.005) as well as pulmonary hypertension (OR 0.34, p = 0.01). Conclusion: In this study, MR decreased or disappeared in a high percentage of patients after AVR surgery. Independent factors predicting this improvement included the presence of prior coronary lesions, although the improvement is influenced by the diabetic status of the patient, as well as pulmonary hypertension.