Coronary 18F-NaF uptake predicts myocardial infarction in CAD patients

Coronary ¹⁸F-sodium fluoride (¹⁸F-NaF) positron emission tomography (PET) strongly predicts fatal or nonfatal myocardial infarction in patients with established coronary artery disease (CAD), suggests a recent study.

Patients with known CAD underwent ¹⁸F-NaF PET computed tomography and were followed over 42 months (interquartile range, 31–49 months) for fatal or nonfatal myocardial infarction. The coronary microcalcification activity (CMA) determined the total coronary ¹⁸F-NaF uptake.

The authors conducted a posthoc analysis of data collected for prospective observational studies. A total of 293 participants (mean age, 65 years; 84 percent men) were included, of whom 203 (69 percent) showed increased coronary ¹⁸F-NaF activity (CMA >0). Only those with increased coronary ¹⁸F-NaF activity experienced fatal or nonfatal myocardial infarction (20 of 203 with CMA >0 vs 0 of 90 with CMA of 0; p<0.001).

Receiver operator curve analysis showed that ¹⁸F-NaF CMA provided the highest prediction of fatal or nonfatal myocardial infarction, besting coronary calcium scoring, modified Duke CAD index, and Reduction of Atherothrombosis for Continued Health (REACH) and Secondary Manifestations of Arterial Disease (SMART) risk scores (area under the curve: 0.76 vs 0.54, 0.62, 0.52, and 0.54, respectively; p_all<0.001).

Patients with CMA >1.56 were seven times at greater risk of fatal or nonfatal myocardial infarction (hazard ratio, 7.1, 95 percent confidence interval, 2.2–25.1; p=0.003), independent of age, sex, risk factors, segment involvement and coronary calcium scores, presence of coronary stents, coronary stenosis, REACH and SMART scores, the Duke CAD index, and recent myocardial infarction.

“Reliable methods for predicting myocardial infarction in patients with established CAD are lacking,” the authors said. “Coronary ¹⁸F-NaF PET provides an assessment of atherosclerosis activity.”