Diagnostic performance of MSCT in cardiomyopathy patients

Cardiomyopathy
In 2006, the American Heart Association (AHA) published a scientific statement
that proposed a contemporary definition and classification of the
cardiomyopathies (CM);
"Cardiomyopathies are a heterogeneous group of diseases of the myocardium
associated with mechanical and/or electrical dysfunction that usually (but not
invariably) exhibit inappropriate ventricular hypertrophy or dilatation and are
due to a variety of causes that frequently are genetic. Cardiomyopathies either
are confined to the heart or are part of generalized systemic disorders, often
leading to cardiovascular death or progressive heart failure-related
disability1. Disease confined to the heart is called primary whereas
generalized disease is called secondary.

The 2006 AHA scientific statement makes a distinction between cardiomyopathy
and cardiac dysfunction due to known entities such as hypertension, valvular
disease, congenital heart disease and also ischemic heart disease. This means
that the term *ischemic cardiomyopathy* in theory is false1-2. In clinical
practice however the term cardiomyopathy is also used for cardiac dysfunction
of known cause. Here, the term cardiomyopathy will also be used for disease
caused by coronary atherosclerosis or other known causes.

To evaluate the diagnostic effectiveness of MSCT in making a distinction
between ischemic and non-ischemic cardiomyopathy in symptomatic patients. If
MSCT proves to be a reliable diagnostic, ICA can be reserved for therapeutic
purposes only. This will safe money and complications as previously discussed.
Using the calcium score as a *rule out test* of disease, radiation exposure can
be minimal especially in this patient group because around 30-50% of the
cardiomyopathy patients is expected to be diagnosed as having non ischemic
disease17. After a positive calcium score, both MSCT-CA and invasive
angiography (ICA) will be performed and results (diagnoses) will be compared.

Prospective, diagnostic study. The primary endpoint will be the correct
diagnosis by MSCT of ischemic versus non-ischemic cardiomyopathy. All patients
that: visit a cardiologist of the Erasmus MC for specified complaints (see
*patient population/ base*), fulfill the inclusion criteria, have no reason for
exclusion and are willing to participate, will be included in the study in a
chronological order. Patients that already visited a cardiologist at the
Erasmus MC for specified complaints and are waiting for ICA, will also be asked
to participate.

All patients will have ICA after MSCT-CA. MSCT-CA results will not be told to
the patient before ICA. Whether the patient undergoes ICA or not depends on the
MSCT-calcium scan results as previously mentioned. Results in grey boxes will
be calculated, examined and compared

Participating in this study implies very little risk. There is a small risk of
hematoma at the location of the i.v. cannula. If the patient has a positive
calciumscore, contrast agents will be used during the remainder of the scan
procedure. There is a small chance of minor nausea or skin rash. Only very
seldom contrast agents provoke temporary renal failure and shock. All equipment
needed for these (emergency) situations is available in the CT room. Further it
is important to note that the risk of any complication is minimized by
evaluating the patient risk profile before scanning. If there are any risk
factors the scan will not be done.