Anatomic correlates of a normal perfusion scan using 64-slice computed tomographic coronary angiography

Area of Science:

• Cardiology
• Radiology
• Medical Imaging

Background:

• Myocardial perfusion imaging (MPI) and multislice computed tomography (MSCT) are diagnostic tools for coronary artery disease (CAD).
• MSCT can detect early atherosclerosis before myocardial perfusion abnormalities appear.
• Normal MPI results do not always exclude significant CAD, including high-risk conditions like left main or 3-vessel disease.

Purpose of the Study:

• To evaluate the range of coronary artery anatomic findings using MSCT in patients with normal MPI results.
• To determine the prevalence of normal coronary arteries, nonobstructive CAD, and obstructive CAD in patients with normal MPI.
• To assess the occurrence of high-risk CAD (left main and 3-vessel disease) in this patient group.

Main Methods:

• 180 patients presenting with chest pain underwent both MPI (gated single-photon emission computed tomography) and 64-slice MSCT.
• Coronary artery anatomy was assessed by MSCT in patients with normal MPI findings.
• Prevalence of normal arteries, nonobstructive CAD, obstructive CAD, and high-risk CAD was determined.

Main Results:

• Of 97 patients with normal MPI, 38 (39%) had normal coronary anatomy.
• Nonsignificant CAD was found in 37 patients (38%), and significant CAD in 18 patients (19%).
• Only 4 patients (4%) had high-risk CAD (2 left main, 2 three-vessel disease).

Conclusions:

• Normal MPI results can coexist with a spectrum of coronary artery disease, from normal anatomy to obstructive CAD.
• MPI alone cannot rule out the presence of nonobstructive or obstructive coronary artery disease.
• High-risk coronary artery disease was uncommon in patients with normal MPI findings.