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with severe MR already at rest: During 1-year follow-up, 37 patients died, and 71 patients were re-admitted to
the hospital because of heart failure. In this regard, 13 patients (30%) with dynamic severe MR experienced the
combined endpoint, while 72 patients (43%) with severe MR at rest did as well (P = 0.121). Moreover, the majority
of patients with dynamic severe MR similar to patients with severe MR at rest experienced clinical improvement
from NYHA class III/IV to I/II (59% vs. 56%; P = 0.566).

Conclusion: The data presented provide evidence of a clinical benefit from PMVR using MitraClip in patients with
moderate MR at rest who display exercise-induced increases in MR severity during handgrip exercise.

Keywords: Percutaneous mitral valve repair, MitraClip, dynamic mitral regurgitation, exercise echocardiography

INTRODUCTION
[1]
In recent years, cardiologists have increasingly recognized the dynamic nature of mitral regurgitation (MR) .
In degenerative MR (DMR) about one-third of patients with moderate to severe MR display notable
2
exercise-induced increases in MR severity [increase in effective regurgitant orifice area (EROA) > 10 mm
and regurgitation volume (RVol) >15 mL] . Owing to these findings, there is a recommendation for
[2]
exercise echocardiography during the diagnostic work-up of symptomatic patients with DMR in whom
[3,4]
there is a discrepancy between symptoms and the severity of MR at rest . In functional MR (FMR)
exercise-induced changes in MR severity are also common and may provide prognostic information on the
clinical course of heart failure . European Society of Cardiology (ESC) guidelines emphasize the role of
[5-7]
exercise echocardiography in unmasking significant dynamic MR in patients with left ventricular systolic
dysfunction, since resting MR severity may not correlate with the potentially clinical significant increase in
[4]
MR during exercise . Percutaneous mitral valve repair (PMVR) with the MitraClip system has emerged
as a treatment option for patients with DMR and FMR, who are inoperable or have a high surgical risk.
However, current recommendations do not cover dynamic MR since data on the safety and efficacy of
PMVR are lacking in these patients. Likewise, there are only scarce data on exercise echocardiography in
patients undergoing PMVR, of whom the majority may be too frail to undergo traditional bicycle exercise
testing.

In the current study, we report our experience of PMVR using the MitraClip in patients with moderate MR
at rest and dynamic severe MR during handgrip exercise, compared to patients with severe MR already at
rest.

METHODS
Study design
We included patients who underwent PMVR with the MitraClip system at our institution from 2012 to
2016 in an all-comers observational study. Patients with moderate to severe MR at rest received handgrip
echocardiography prior to MitraClip implantation. Handgrip echocardiography was performed in patients
with a discrepancy between symptoms and echocardiographic findings at rest, giving rise to the suspicion
of an exercise-induced increase in MR severity. Our interdisciplinary heart team classified all patients as
inoperable or at high-risk for surgery. The study was performed in accordance with the Declaration of
Helsinki and was part of a registry, which was approved by the local ethics committee of the Heinrich-
Heine University and registered at www.clinicaltrials.gov (NCT02033811).

Follow-up
Patients were routinely followed by referring cardiologists and scheduled for a single outpatient visit
12 months after MitraClip implantation in our specialty clinic for structural heart disease. The clinical