This article is more than 5 years old. Information may no longer be current.

PET myocardial perfusion imaging improved risk stratification

Issue: January 2013

Add topic to email alerts

Receive an email when new articles are posted on

Please provide your email address to receive an email when new articles are posted on .

Subscribe

Added to email alerts

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

Back to Healio

We were unable to process your request. Please try again later. If you continue to have this issue please contact customerservice@slackinc.com.

Back to Healio

Assessing the extent and severity of ischemia and scarred myocardium using PET myocardial perfusion imaging in addition to traditional clinical risk factors led to significant risk reclassification in 12% of patients with suspected or known CAD, according to new data.

Although previous data have demonstrated an association between abnormal myocardial perfusion imaging (MPI) and adverse clinical outcomes, these studies were generally small and single-center, therefore limiting their ability to determine the clinical utility of PET MPI, researchers wrote in the Journal of the American College of Cardiology.

To investigate this association in a larger trial, researchers evaluated 7,061 patients from four centers who underwent a rest or stress rubidium-82 PET MPI. Median follow-up was 2.2 years. They also analyzed net reclassification improvement and integrated discrimination analyses.

Risk for cardiac death increased with each 10% myocardium abnormal with mildly (HR=2.3; 95% CI, 1.4-3.8), moderately (HR=4.2; 95% CI, 2.3-7.5) or severely (HR=4.9; 95% CI, 2.5-9.6) abnormal stress PET. When added to clinical information, including age, female sex, BMI, history of hypertension, diabetes, dyslipidemia, smoking, angina, beta-blocker use and prior revascularization, and resting heart rate, percent myocardium ischemic and percent myocardium scarred resulted in significant risk reclassification for cardiac death (net reclassification improvement, 0.116; 95% CI, 0.021-0.21) and smaller improvements in risk assessment for all-cause death.

“The results of this large multicenter registry demonstrated that in patients with known or suspected CAD, [rubidium-82] PET MPI provided powerful and incremental risk stratification,” the researchers wrote. “Assessment of the magnitude of ischemia and scar on PET MPI adds to the reclassification of risk for cardiac death in one of 9 patients undergoing clinical PET MPI.”

In an editorial comment, Paul Schoenhagen, MD, and Rory Hachamovitch, MD, both of the Cleveland Clinic, Heart and Vascular Institute and Imaging Institute in Ohio, noted that these results raise important questions, as the researchers examined a larger population of patients than in previous studies. Nevertheless, they highlighted the need for more data.

“The role of testing is defined in the context of a specific intervention and whether the effectiveness of the intervention is improved by the use of an imaging study to identify optimal candidates for treatment,” they wrote. “This framework potentially introduces a new paradigm for defining the incremental value of a test, which is an important consideration in the current health care environment. However, this process is neither simple nor inexpensive and will require prospective randomized clinical trials, validating the results and hypotheses generated by observational data.”

For more information:

Dorbala S. J Am Coll Cardiol. 2012;doi:10.1016/j.jacc.2012.09.043.

Schoenhagen P. J Am Coll Cardiol. 2012;doi:10.1016/j.jacc.2012.09.044.

Disclosure: See the study for a full list of researchers’ disclosures. Schoenhagen and Hachamovitch report no relevant financial disclosures.