Diagnostic utility of tomographic myocardial perfusion imaging with technetium 99m furifosmin (Q12) compared with thallium 201: Results of a phase III multicenter trial

Background: Based on physical properties, ^99mTc-labeled perfusion agents offer several advantages over ²⁰¹Tl for myocardial perfusion imaging. The results of in vivo and experimental studies, along with preliminary experience in human subjects, have shown ^99mTc-labeled furifosmin to be a promising new perfusion tracer. The purpose of this study was to evaluate the safety of a new myocardial perfusion agent, ^99mTc-labeled furifosmin (Q12), and determine the concordance of furifosmin perfusion scintigraphy to ²⁰¹Tl imaging. In addition, we sought to determine the normalcy rate of myocardial scintigraphy with furifosmin. Methods and Results: One hundred fifty patients constituted the study group in this multicenter trial. Patients underwent exercise testing with furifosmin injected at peak exercise, and tomographic imaging was begun 15 to 30 minutes afterward. After a separate injection, resting images were obtained 3 to 4 hours later. Thallium scintigraphy was performed within 2 weeks of the furifosmin scans, after a similar exercise workload. Patients with a low likelihood of coronary artery disease (n=39) also underwent furifosmin imaging. All images were processed and displayed in uniform manner and interpreted by a panel of readers. No adverse effects or clinically important laboratory alterations were related to furifosmin imaging. Image quality was slightly better with furifosmin than with thallium. The overall concordance between the perfusion studies was 86% (kappa value=0.669). The normalcy rate for furifosmin scintigraphy was 100%. Conclusions: ^99mTc-labeled furifosmin is a promising new ^99mTc-labeled myocardial perfusion agent, providing diagnostic results similar to those obtained with ²⁰¹Tl.