Management of arrhythmias in mitral valve prolapse: are we making the right choises for our patients?

Background For patients with mitral valve prolapse (MVP) there is no established medical therapy to suppress ventricular arrhythmias and relieve arrhythmic symptoms since antiarrhythmic medication for MVP has not been evaluated in randomized controlled trials. Additionally, patients with MVP are underrepresented in studies examining the effect of antiarrhythmic medication on the reduction of premature ventricular complexes (PVCs). Purpose We aimed to evaluate the antiarrhythmic drug use for ventricular arrhythmias in MVP patients, and to assess the potential efficacy of different antiarrhythmic medications on the reduction of ventricular arrhythmias. We hypothesized that betablockers are widely used but have a minor effect on ventricular arrhythmia reduction, while other less commonly used antiarrhythmic medications have a greater efficacy. Methods This retrospective longitudinal observational study included patients with MVP referred to our tertiary centre that underwent Holter monitoring. PVC and non-sustained ventricular tachycardia (NSVT) burden were assessed by repeated Holter monitorings. Patients undergoing mitral valve surgery or catheter ablation treatment were censored from follow-up analysis from the time of the procedure. Associations were assessed by mixed linear or negative binomial regression with random effects on individual level, as appropriate. Results We included 119 MVP patients (median age 46 years [interquartile range, IQR, 35-59], 67% female) with a total of 302 Holter monitorings. Of these were 72 (61%) patients treated with antiarrhythmic medication and 196 (65%) Holter monitorings were performed on antiarrhythmic treatment. Total burden of PVCs at first Holter monitoring was 0.6% per 24 hours (IQR 0.06-3.6) (0.5% [IQR 0.03-3.3] on treatment and 0.9% [IQR 0.1-3.8] on no treatment). Betablocker was the most commonly used antiarrhythmic medication (137 Holter monitorings [45%] in 64 [54%] patients), followed by flecainide (38 [13%) in 13 [3%] patients), non-dihydropyridine calcium channel blocker (11 [4%] in 4 [3%] patients), sotalol (7 [2%] in 2 [2%] patients) and dronedarone (3 [1%] in 1 [1%] patient). Compared to no treatment, only flecainide was associated with a lower PVC burden (-2.2% per 24 hours [95% confidence interval, CI, -4.2 to -0.3], p<0.03), with no increased rate of NSVT (p>0.05). Regarding NSVT, only sotalol showed a reduction in NSVT incidence (incidence rate ratio 0.02 [95% CI 0.002-0.29], p=0.004). Conclusion Betablocker was the most commonly used antiarrhythmic medication in MVP patients but showed no reduction in ventricular arrhythmias. Flecainide and sotalol were less frequent used but our study suggested a reduction in ventricular arrhythmias. Randomized control trials are needed to assess the efficacy and safety of different antiarrhythmic medications in MVP.