Predicting cardiovascular events

Manjula Puthenedam, PhD, Associate Editor

PET imaging plays an important role in the assessment of myocardial blood flow and can guide interventions for preventing the development of future cardiovascular events. For instance, researchers have used PET with sympathetic stress for risk assessment of coronary endothelial function--the earliest indication for coronary atherosclerosis, according to an article published in the Journal of Nuclear Cardiology.

PET is also well-suited for the acute and longitudinal evaluation of treatment. There is a need to continue developing this method for the evaluation of the effects of cardiac disease treatments, said Keiichiro Yoshinaga, MD, PhD, associate professor of photobiology at Hokkaido University Graduate School of Medicine in Sapporo, Japan.

Future applications will evolve with the availability of 18F-labeled PET agents. Flurpiridaz F-18, a PET perfusion agent, has completed a phase II clinical trial. The phase III clinical trial will compare its diagnostic efficacy with SPECT myocardial perfusion imaging in the detection of significant coronary artery disease.

At the American College of Cardiology meeting this year, researchers presented data that the coronary artery calcification detected during the CT scan for attenuation correction for stress Rb-82 PET myocardial perfusion imaging was a predictor of cardiovascular events in patients with abnormal perfusion studies irrespective of the degree of ischemia.

There was an increased risk prediction of coronary artery calcification in patients with higher summed stress scores, but there was no statistical difference in events for coronary artery calcification in those with a normal PET, according to the researchers from the Henry Low Heart Center at the Hartford Hospital in Farmington, Conn.

In other features, both “half-time” and “half-dose” wide-beam reconstruction software can provide myocardial perfusion SPECT quality superior to full-time OSEM software, with an associated decrease in scan acquisition time and patient radiation exposure in a study published in the Journal of Nuclear Cardiology. The most likely explanation given by the researchers for this difference is that in most patients the administered activity for the 'half-dose' protocol was actually greater than half that was used for the 'full-dose' protocol.

New advancements in dedicated cardiac SPECT cameras through innovative design and software algorithms have also been published in the Journal of Nuclear Medicine. The dedicated cardiac SPECT cameras will have the ability to acquire images of the heart in less time and with better resolution than conventional SPECT cameras, according to researchers.

On these topics, or others, please feel free to contact me.

Manjula Puthenedam, PhD
mputhenedam@trimedmedia.com