Abstract
BACKGROUND AND AIMS: Mitral valve prolapse (MVP) is associated with progressive mitral regurgitation (MR) requiring surgical correction. A subset of patients with MVP experience ventricular arrhythmias (VA), and mitral annular disjunction (MAD) has been reported as a risk factor. This study aimed to assess the long-term risk of VA in patients with MAD and MVP undergoing mitral valve surgery for MR. METHODS: Patients with MVP with moderate or severe degenerative MR undergoing mitral valve surgery (repair or replacement) in 2010-22 at Karolinska University Hospital were included. Mitral annular disjunction length, referring to true MAD, was measured at end systole on pre- and post-operative transthoracic echocardiography. The primary outcome consisted of VA including hospitalizations, outpatient visits or ablation for confirmed sustained or non-sustained ventricular tachycardia, or high burden of premature ventricular complexes and assessed from medical records. RESULTS: Of 599 patients undergoing mitral valve surgery, 96 (16%) had pre-operative MAD. The median MAD length was 8.0 [inter-quartile range (IQR) 5.0-10.0] mm. Compared with patients without MAD, patients with MAD were younger (55 ± 15 vs 63 ± 11 years), were more often women (31% vs 17%), and had more Barlow's disease (70% vs 27%). Mitral annular disjunction was surgically corrected in all patients. During a median follow-up time of 5.4 (IQR 2.8-7.5) years, patients with pre-operative MAD had a higher risk of VA (hazard ratio adjusted for age and sex 3.33, 95% confidence interval 1.37-8.08) regardless of repair/replacement (Pinteraction = .18). CONCLUSIONS: Mitral annular disjunction in patients with MVP and MR was associated with a three-fold increased long-term risk of VA post-mitral valve surgery, despite anatomical correction of MAD.