Mitral annular disjunction and mitral valve prolapse: long-term risk of ventricular arrhythmias after surgery

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.

Keywords: Mitral annular disjunction; Mitral regurgitation; Mitral valve prolapse; Mitral valve surgery; Ventricular tachycardia.

structured graphical abstract

CI, confidence interval; HR, hazard ratio; MAD, mitral annular disjunction.

Figure 1

Assessment of mitral annular disjunction by transthoracic echocardiography. (A) Transthoracic echocardiographic parasternal long-axis image demonstrating mitral annular disjunction with mitral valve prolapse near ventricular end systole; (B) transthoracic echocardiographic long-axis zoomed image demonstrating mitral annular disjunction; and (C) transthoracic echocardiographic apical three-chamber view demonstrating mitral annular disjunction with mitral valve prolapse near ventricular end systole

Figure 2

Assessment of pseudo-mitral annular disjunction by transthoracic echocardiography. (A) and (B) Pseudo-mitral annular disjunction. The white point marks the hinge line. The dotted line marks the posterior leaflet. If the annular plane is erroneously set at the leaflet bending point in the atrium, then pseudo-mitral annular disjunction occurs (double dotted arrow)

Figure 3

Cox regression survival age-adjusted analysis for all-cause death (A) and Kaplan–Meier survival analysis for heart failure hospitalization (B), new-onset atrial fibrillation or flutter (C), and new-onset stroke (D) stratified by the presence of MAD in patients undergoing mitral valve repair or replacement