Assessment of the risk of atrial fibrillation after mitral valve re- construction using various types of support rings up to 12 months after operation

Aim . To evaluate the effect of mitral valve (MV) reconstruction using rigid and superelastic support rings for up to one year in patients with mitral regurgitation (MR) II according to A. Carpentier on the development of atrial fibrillation (AF). Methods . The study included 62 patients with indications for surgical correction of MR and sinus rhythm (SR): group I (n=31) - with implantation of the biological semi-rigid saddle closed ring NeoRing and II (n=31) - with implantation of the rigid open ring RIGID. The average age of patients was 56.6±11.2 years and 58.0±10.2 years in groups I and II. Both groups were comparable in gender (men - 67.7% and 61.3%), age, comorbidity, functional class of chronic heart failure according to NYHA. The rhythm in patients was assessed by Holter monitoring at control points after 9 days and 12 months. Results . The duration of artificial circulation, aortic occlusion, and the incidence of isolated P2-segment prolapse did not differ in the comparison groups. A positive effect on the reverse remodeling of the left heart was revealed: the end-diastolic dimension of the left ventricle (p<0.001), the left atrium (p<0.001), a decrease in the overload of the pulmonary circulation and a decrease in pressure in the pulmonary artery (p<0.001). According to the Holter monitoring data, all patients had SR. Both groups showed a satisfactory result at the hospital stage in the form of restoration of the locking function of the MV (p<0.001) and a low frequency of the revealed maximum MR up to grade 1 in group I - 9.7% and II - 29% (p=0.292). However, patients with RIGID had higher values of transvalvular diastolic gradient on MV and transvalvular flow velocity (p < 0.001). In group II, the values of transvalvular diastolic gradient on MV were Pcp 3.34±1.01 mm Hg, versus 2.39±0.62 mm Hg in group I (p < 0.001), transvalvular flow velocity in group II was Vcp 79±15 cm/sec versus 66±12 cm/sec in group I, respectively (p < 0.001). After 12 months, the RIGID group more often showed a change from SR to AF - 11 cases (35.5%), in NeoRing - 4 (12.9%). According to echocardiography data after 12 months, freedom from MR ≥ grade 2 in group I was 93.5%, versus 77.4% in group II (p=0.076). In addition, patients in group II maintained higher values of transvalvular diastolic gradient on MV - Pcp 3.70 [3.00; 4.40] mmHg, versus 2.3 [2.05; 2.85] mmHg (p<0.001), as well as higher transvalvular flow velocity - Vcp 79 [71; 94] cm/sec versus 70 [64; 79] cm/sec (p=0.017). AF developed 12 months after surgery in those patients whose transvalvular diastolic gradient on the MV exceeded 2.7 mm Hg, as well as in patients with developed MR ≥ grade. Conclusions . The development in the medium term, after reconstruction of the mitral valve with a support ring, of an increased transmitral diastolic gradient and MR ≥ grade 2 is the cause of the development of AF, while the implantation of a rigid ring is accompanied by a high risk of developing AF within 12 months after surgery (p=0.029).