Morphology and clinical significance of mitral valve prolapse among the polish population of the MITPROL AR-PL registry
Authors: Dziadosz D , Danilowicz-Szymanowicz L , Wejner-Mik P , Kowalczyk-Domagala M , Wierzbowska-Drabik K , Jaworski K , Kustrzycka-Kratochwil D , Uzieblo-Zyczkowska B , Brzezinska B , Polewczyk A , Kurnicka K , Budnik M , Gackowski A , Kukulski T , Mizia-Stec K 
Published: January 2025

Abstract

Introduction
The role of mitral valve prolapse (MVP) as an arrhythmic substrate rather than an isolated structural defect is under investigation. There is a possible link between the MVP, its morphology, and arrhythmic MVP (aMVP).

Purpose
To obtain data on the morphology and clinical significance of MVP in the Polish population.

Methods
417 patients with MVP (mean age 45.5 years-yrs.; females: 249/59.7%) were enrolled into the prospective observational registry MITPROL AR-PL of the Polish Cardiac Society. Data was obtained from 23 Polish tertiary medical centers; the recruitment lasted 12 months. The analysis included demographics, clinical symptoms, 12-lead ECG, 24-hour Holter ECG, transthoracic, and transesophageal echocardiography. The MVP morphology was analyzed and defined as Barlow’s disease (BD), Forme Fruste (FF), and Fibroelastic deficiency (FED), according to standardized criteria. Groups were dichotomized into aMVP and non-arrhythmic MVP (non-aMVP) following the 2022 European Heart Rhythm Association consensus [1]. Patients who fulfilled the arrhythmic criteria but had proarrhythmic comorbidities comprised the MVP A+C (arrhythmia + comorbidities) group. Analysis was performed for the total population and age-divided subgroups: pediatric (0-18 yrs.), young adults (19-45 yrs.), middle-aged (46-59 yrs.), elderly (60+ yrs.).

Results
MVP population in the age subgroups: pediatric 86 (20%), young adults 120 (29%), 67 (16%) middle-aged, 144 (35%) elderly. BD was present in 140 (34%), FF in 242 (58%), and FED in 35 (8%). Bileaflet prolapse occurred in 228 (55%), anterior leaflet prolapse in 65 (16%), and posterior leaflet prolapse in 124 (29%). The frequency of the MVP morphology in the consecutive age subgroups was akin. The aMVP group consisted of 62 (15%), non-AMVP 336 (80%), and MVP A+C of 19 (5%) patients. Distribution of aMVP in the age subgroups: pediatric- 11%, young adults- 42%, middle-aged- 23%, elderly- 24%, 76% of aMVP patients were &lt; 60 yrs. The aMVP corresponded mainly to the following MVP morphology: BD– 29 (47%) vs. 103(31%) in non-AMVP (p=0.01). Bileaflet prolapse was the most frequent for aMVP (46/74%) vs. non-aMVP (175/52%) (p=0.001), respectively anterior leaflet prolapse 4 (7%) vs. 57 (17%) (p=0.03), posterior leaflet prolapse 12 (19%) vs. 104 (31%) (p=0.06). Moderate to severe MR was observed in 35 (56%) aMVP vs. 196 (58%) non-aMVP (p=0.8), MAD in 48 (77%) aMVP vs. 193 (57%) non-aMVP (p=0.003), Pickelhaube sign in 28 (45%) aMVP vs. 98 (29%) non-AMVP cases (p=0.01). MAD diameter was higher in the aMVP (8.6 ± 2.7 mm) vs. the non-aMVP (7.2 ± 2.5 mm) group (p=0.001). The age of MVP A+C group was higher, with 84% of patients &gt;60 yrs. vs. 24% &gt;60 yrs. in the aMVP (p&lt;0.0001). MVP morphology in the MVP A+C was: BD 8 (42%), FF 10 (53%), and FED 1 (5%).

Conclusion
The MVP is a primary and heterogenous disease, and aMVP variant is rare. The aMVP population differs significantly from non-AMVP and MVP A+C populations.
Mitprol AR-PL Methodology
Mitprol AR-PL Population