Arrhythmic mitral valve prolapse detection using long-term ambulatory rhythm monitoring - the ALARM-PILOT study

Background

Mitral valve prolapse (MVP) is the most common valvular heart disease. A small subset develops ventricular arrhythmias, known as arrhythmic MVP (AMVP). Diagnosis often relies on repeated 24-hour Holter monitoring, but its sensitivity is prone to large day-to-day variability.

Purpose

To study the diagnostic yield of long-term rhythm monitoring in patients with MVP.

Methods

The ALARM-PILOT is a prospective interventional single-centre cohort study including patients with MVP (without prior AMVP) and patients with known AMVP as a positive control group. AMVP was defined according to the EHRA consensus as MVP with frequent (≥ 5% PVC burden) or complex (nsVT, VT or VF) ventricular arrhythmias, in the absence of another arrhythmic substrate. Participants underwent a 14-day patch-based ambulatory rhythm monitoring. For comparison with conventional 24-hour monitoring, analyses were performed using the first 24 hours of the same 14-day recording. Time to fulfilling the AMVP criteria was calculated, continuous data are presented as median [Q1–Q3].

Results

Thirty-nine patients were included, baseline characteristics are presented in Table 1. The median recording duration was 13.6 days [12.9-14.1], with 90.4% [81.6-95.8] of data analysed. Ten patients (25.6%) experienced minor adverse events related to patch adhesion, without serious complications.

Figure 1 shows the cumulative incidence of meeting AMVP diagnostic criteria for both groups. Overall, 21 of 39 patients (53.8%) fulfilled AMVP criteria during monitoring, including 7 of 19 patients with MVP without prior AMVP (33.3%) and 14 of 20 patients in the known AMVP group (66.7%).

Of these 21 patients, only 7 (33.3%) met diagnostic criteria within the first 24 hours of recording, whereas the remaining 14 were identified during subsequent monitoring days. The first qualifying event was ≥ 5% PVC burden in 4 and nsVT in 17 patients. Particularly in patients with MVP, only 1 patient (5.3%) fulfilled AMVP criteria within the first 24 hours, while 6 additional new diagnoses (31.5%) were established between day 2 and 14.

Conclusion

Long-term ambulatory rhythm monitoring substantially improves the diagnostic yield for AMVP detection when compared with the conventional 24-hour monitoring. Validation in larger, multicentre cohorts is required to determine its impact on clinical management.Table 1Figure 1