Background:
Chronic heart failure (HF) is frequently accompanied by functional mitral regurgitation (FMR)
caused by left ventricular (LV) remodeling and subsequent papillary muscle displacement
resulting in mitral valve (MV) leaflet tethering, dilatation and flattening of the mitral
annulus and reduced closing forces. Up to moderate FMR affects the majority of patients with
systolic heart failure - roughly 80% - still independently increasing mortality. Every fifth
patient with chronic heart failure experiences a progression of FMR during the first three
years of follow up despite guideline directed heart failure therapy, which is independently
associated with a poor prognosis. Furthermore, MR is well known to have a strong dynamic
component not only during the cardiac cycle at rest and with exercise.
Aims of the study:
The investigators therefore aim to assess whether stress tests in patients with functional
mitral regurgitation unmasks significant dynamic mitral regurgitation or might aid to
identify patients at risk of FMR progression in patients with functional mitral regurgitation
in heart failure with reduced ejection fraction (HFrEF) under guideline directed medical
therapy.
Study design:
The investigators will prospectively perform stress tests in all patients with non-severe FMR
that are routinely seen in the heart failure outpatient clinic.
Study patients:
Patients with stable chronic heart failure on optimal medical therapy, who undergo routine
ambulatory clinical control visits in the heart failure outpatient ward of the Medical
University of Vienna, will be included in the present study. A written informed consent will
be obtained before inclusion. Inclusion criteria will be a non-severe FMR, an age of at least
18 years and stable heart failure related medical therapy in the last 3 months.
Methods:
All patients that are willing to participate will undergo stress testing (i.e. volume
challenge and low dose dobutamine stress) to determine whether patients display severe
dynamic FMR under stress conditions. Within the registry patients will be followed-up during
routine ambulatory visits for three years. Patients with severe dynamic functional mitral
regurgitation will be compared to patients without severe dynamic FMR. Record of clinical
events during the FUP will be performed. Routine laboratory parameters, have been measured at
inclusion. Additionally, neurohormone patterns will be measured at baseline and at peak
stress.
Sample size:
Expecting a prevalence of severe dynamic FMR of 20%, the investigators would include a total
of 150 chronic heart failure patients taking also into account a study-dropouts of 20% ( loss
of follow-up and mortality).