MR Adenosine Perfusion in the functional evaluation of patients undergoing PCI for single or two vessel disease

The increase in flow through the coronary arteries relies mostly on
vasodilatation. Compensatory vasodilatation distal to a stenosis is able to
maintain flow during rest, but during stress (or pharmacologically induced
stress) conditions this capacity is exceeded. Adenosine induces vasodilatation
of the coronary arteries. Stenotic coronary arteries bear the capacity to
further dilate, which creates a relative area of hypoperfusion in the supplied
myocardium compared to segments supplied by normal coronary arteries.
A persisting perfusion abnormality after coronary intervention is associated
with a higher risk of significant restenosis. Therefore a non-invasive imaging
technique that can accurately assess the functional effect of percutaneous
coronary intervention would be ideal.

To assess the diagnostic value of adenosine myocardial stress perfusion MR in
the functional evaluation of patients undergoing a standard PCI with
FFR-measurements for single or two vessel disease.

Prospective, exploratory study in patients with single or two vessel disease,
who are planned for PCI on the basis of a CAG. an adenosine perfusion MR will
be performed on the day of admittance and one day after the PCI.

Untill present day no hazardous effect of MRI are documented. MRI is
contra-indicated in patients with non-MR compatible implants and claustrofobia.
The contrast agent used with MR examinations, Gadoterate meglumine is
considered very safe, and has been used in clinical practice for many years. In
some cases nausea (1-2%) or hives(<1%) can occur. In very rare cases an
anaphylactoid reaction can occur.
Adenosine is well tolerated and is widely used in a clinical setting for
visualisation of myocardial perfusion in nuclear imaging, as well as in MRI.
Contra-indications for adenosine are documented and described in the exclusion
criteria. Severe side-effect are rare,and consist of AV-block, ventricular
fibrillation, bradycardia, hypotension, bronchospasm and ST-depression.
Side-effects expressed in order of incidence are: flushing (37-44%), chest
discomfort (35-40%), dyspnoe (28-35%), headache (14-18%), anginal discomfort of
neck, throat or jaw (12-15%), gastro-intestinal discomfort (13-15%),
lightheadedness (9-12%), ST-segment-depression (3%), first-degree AV-block
(3%), second-degree AV-block (3%), third-degree AV-block (0.8%), hypotension
(2%), arrhythmia (1%). Adenosine is contra-indicated in second or third degree
AV block, sick-sinus syndrome, asthma and other obstructive pulmonary disease,
severe hypotension, unstable angina, heart failure, prolonged QT-interval and
pregnancy.