Quantifying myocardial blood flow (MBF) with CT perfusion (CTP) imaging can accurately predict major adverse cardiac events (MACEs). It also showed improved risk stratification in stenosis patients when paired with coronary CT angiography (CTA), according to a recent JACC: Cardiovascular Imaging study.
Researchers, led by Satoshi Nakamura, MD, with Mie University Graduate School of Medicine in Japan, analyzed 332 patients with suspected coronary artery disease (CAD). All patients underwent both CTA and dynamic CTP.
The group examined myocardial segments and used normalized MBF values to create a summed stress score. Segments, which scored from 0 to 4, were normal to most restricted flow. Abnormal perfusion was considered to be a combined total of 4 or higher.
After an average follow-up time of 2.5 years, 19 patients had a MACE, which was defined as cardiac death, nonfatal myocardial infarction, unstable angina or hospitalization for congestive heart failure.
Abnormal perfusion proved the strongest predictor for MACE, and had a hazard ratio of 5.7 when adjusted for obstructive CAD on CTA.
The annual MACE rates of patients with at least 50 percent stenosis on CTA and abnormal perfusion determined by CTP were 12.2 percent. However, that event rate fell to 1.5 percent when obstructive CAD was evident in normal blood flow.
“The main findings of our study were that dynamic CTP had an incremental prognostic value over CTA and that abnormal perfusion was associated with worse prognosis among those who had obstructive CAD,” authors concluded. “The addition of dynamic CTP to CTA allows improved risk stratification of patients with CTA-detected stenosis.”
Matt joined Chicago’s TriMed team in 2018 covering all areas of health imaging after two years reporting on the hospital field. He holds a bachelor’s in English from UIC, and enjoys a good cup of coffee and an interesting documentary.