Hemodynamic Stress Test in Severe Mitral Regurgitation (HEMI)
Hemodynamic Stress Test in Severe Mitral Regurgitation (HEMI)
The preferred treatment of organic mitral regurgitation (MR) is mitral valve repair.
 Optimally this should be timed so late that it commensurate with the risk of surgery and
 before irreversibly damage of the heart and pulmonary vessels. The aim is to obtain an
 understanding of the differences between the symptomatic and asymptomatic patient.

 The study will test

 A: Symptomatic organic MR is characterized by higher filling pressure, and higher stroke work
 during physical strain compared with asymptomatic MR.

 B: The extent of myocardial fibrosis is associated with filling pressure and cardiac index 1
 year after mitral valve repair.

 C: Filling pressure can be estimated non-invasively by echocardiography. To test this 40
 patients with asymptomatic MR and 40 symptomatic will undergo a stress echocardiography with
 simultaneous echocardiography and invasive measurement of central hemodynamics. In addition a
 pulmonary function test and cardiac MRI will be performed.
Background

 Degenerative mitral valve disease is the most common cause of organic mitral regurgitation in
 the Western World. The preferred treatment of organic mitral regurgitation is mitral valve
 repair. Optimally this should be timed so late that it commensurate with the risk of surgery
 and before irreversibly damage of the heart and pulmonary vessels. According to the current
 guidelines mitral valve surgery is indicated in symptomatic patients with severe MR or in
 presence of known risk factors. The optimal timing of surgery is still controversial in the
 asymptomatic patients without risk factors.

 The overall aim of the present study is to obtain a better understanding of the central
 hemodynamics at rest and during physical exercise in both symptomatic and asymptomatic
 patients with organic mitral regurgitation, the relation to neurohormonal activation and
 myocardial fibrosis, and to identify noninvasive echocardiographic measures suitable for
 estimation of this.

 A epidemiologic sub-study aims to asses whether MR is associated with inherence, as familial
 clustering of mitral regurgitation earlier has been suggested based only mainly on small
 observational studies, and case reports.

 Methods

 The study will test

 A: Symptomatic organic MR is characterized by higher filling pressure, and higher stroke work
 during physical strain compared with asymptomatic MR.

 B: The extent of myocardial fibrosis is associated with filling pressure and cardiac index 1
 year after mitral valve repair.

 C: Filling pressure can be estimated non-invasively by echocardiography.

 To test this 40 patients with asymptomatic MR and 40 patients with symptomatic MR will
 undergo a stress echocardiography with simultaneous echocardiography and invasive measurement
 of central hemodynamics. In symptomatic patients that undergo surgery, the examination will
 be repeated 1 year after the surgical mitral valve repair.

 In addition pulmonary function test, maximal oxygen consumption test and cardiac MRI will be
 performed.

 The Danish Twin Registry and The Danish National Patient Registry will be used to identify
 twins with MR. The hypothesis is that the concordance rate is higher in monozygotic twins
 compared to dizygotic twins.
Inclusion Criteria:

 -  Organic mitral valve regurgitation with effective regurgitation orifice (ERO)>0.3 cm2

 -  Age > 18 years

 -  Left ventricular ejection fraction (LVEF) > 60% assessed by echocardiography

 -  Signed informed consent

 Exclusion Criteria:

 -  Poor echocardiographic window

 -  Inability to perform bicycle exercise testing

 -  Ischemic or functional (secondary) mitral valve regurgitation

 -  Chronic atrial fibrillation/flutter

 -  Hemodynamic significant aortic valve disease assessed by echocardiography.

 -  Treatment with oral anticoagulants