Reduction in malignant ventricular arrhythmia and appropriate shocks following surgical correction of bileaflet mitral valve prolapse

Background: Bileaflet mitral valve prolapse (MVP) can be associated with malignant ventricular arrhythmias. It is unknown whether surgical correction alone of this mitral valve pathology leads to a reduction in ventricular dysrhythmias. Methods: We retrospectively analyzed 4477 patients who underwent mitral valve surgery from 1993–2013 at Mayo Clinic in Rochester, MN. Among these, eight patients with bileaflet MVP who had an internal cardioverter defibrillator (ICD) in place both pre- and post-surgery were identified. ICD interrogation records were evaluated for episodes of ventricular tachycardia (VT), ventricular fibrillation (VF), and appropriate ICD shock therapy. Results: Of these eight patients, five had a malignant ventricular arrhythmia prior to surgery. Data was available 4.6 ± 2.9 years before versus 6.6 ± 4.2 years following surgical intervention. Among these patients, there was a reduction in VF (0.6 versus 0.14 events per-person-year pre- and post-surgery, respectively), VT (0.4 versus 0.05 events per-person-year pre- and post-surgery, respectively), and ICD shocks (0.95 versus 0.19 events per-person-year pre- and post-surgery) following mitral valve surgery. Conclusions: We report a series of cases where the surgical correction of bileaflet MVP alone was associated with a reduction in malignant arrhythmia and appropriate shocks. These early observations merit further investigation involving larger cohorts to further evaluate the association between abnormal mechanical forces in degenerative mitral valve disease and ventricular dysrhythmias.