Dr. Victoria Delgado
Cardiac magnetic resonance (CMR) plays a
key role in decision making of patients who are candidates for cardiac
interventions and for planning and guiding invasive therapies. The most recent
available evidence on the relevance of CMR
in these fields was summarized in this interesting session opened by Dr.
Nijveldt who highlighted the accuracy of CMR in the measurement of left
ventricular ejection fraction, key criterion to select heart failure patients
for cardiac resynchronization therapy and implantable cardioverter
defibrillators. Furthermore, CMR provides information on determinants of
response to cardiac resynchronization therapy such as left ventricular
dyssynchrony, extent and location of myocardial scar, particularly in the area
targeted by the left ventricular pacing lead. The increase use of
CMR-compatible biventricular pacemakers will enable the monitoring of the
therapy effects with CMR. In addition, 4-dimensional flow CMR may provide
further insight into the interaction between left ventricular mechanics
and flow dynamics.
To select patients with atrial fibrillation
for catheter ablation procedures, dimensions of the left atrium and extent of
atrial scar have been shown to be associated with the procedural success. Dr
Rhode indicated the role of CMR to identify the patients with atrial
fibrillation who may benefit from this therapy and the predominant role of
computed tomography to plan and guide the procedure by fusing computed
tomography data with electromechanical mapping.
Guiding interventions for coronary artery
disease was excellently discussed by Dr. Gaemperli. In stable coronary artery
disease, detection of myocardial ischemia with stress CMR is important to
identify the patients who will benefit from coronary revascularization. This was
demonstrated by a meta-analysis including 11,636 patients with known or
suspected coronary artery disease and mean left ventricular ejection fraction
of 61%. The annualized event rate for cardiovascular death and non-fatal
myocardial infarction was significantly higher among patients with positive
stress CMR. In patients with heart failure, assessment of myocardial viability
with CMR is also relevant to predict improvement in symptoms and global and
regional left ventricular systolic function after coronary revascularization.
Which CMR methodology do we have to use to better identify the patients who
will benefit from intervention? Dobutamine stress CMR to assess contractile
reserve and late gadolinium contrast enhanced CMR to assess myocardial scar are
the preferred methods.
Finally, Dr Gerber provided the
state-of-the art lecture on evaluation with CMR of patients with severe aortic
stenosis who are candidates for transcatheter aortic and mitral valve
replacement. Being a 3-dimensional imaging modality, CMR provides accurate
measurements of the aortic annulus and aortic root, height of the coronary
ostia relative to the annulus and dimensions and tortuosity of the peripheral
arteries. These aspects are important to select the transcatheter aortic
prosthesis size and the procedural approach (transfemoral versus
non-transfemoral). In transcatheter mitral valve replacement, accurate
assessment of the mitral annulus geometry and its relationship with the left
ventricular outflow tract is provided by CMR. Although current developments in
transcatheter aortic valve prosthesis have reduced the incidence of significant
paravalvular regurgitation, CMR seems superior to 2-dimensional
echocardiography to accurately quantify the regurgitant volume.
The results of ongoing research in these
fields will be discussed in Prague 2017 where we hope to see you all!
Our mission: To reduce the burden of cardiovascular disease
© 2017 European Society of Cardiology. All rights reserved