A novel multitargeted intracoronary imaging technique that combines fluorescence lifetime imaging (FLIm) with optical coherence tomography (OCT) is a clinically feasible and safe diagnostic tool for identifying high-risk plaques in patients with coronary artery disease (CAD), according to a first-in-human feasibility study published May 7 in JAMA Cardiology.

Sunwon Kim, MD, PhD, et al., constructed an OCT-FLIm dual-modal imaging system using a 2.6-F dual-imaging catheter to determine whether it could image the microstructure and compositional features of atherosclerotic plaques in coronary arteries simultaneously, and whether FLIm-derived molecular readouts could give complementary information to characterize plaque phenotypes and their association with disease activity.

Between February and August 2022, 40 patients (mean age, 63 years; 20% women) with significant CAD who required coronary revascularization for either acute coronary syndrome (ACS; n=20) or chronic stable angina (CSA; n=20) underwent OCT-FLIm scanning before the intervention. All patients underwent OCT-FLIm and intravascular ultrasound of target/culprit and nontarget/nonculprit lesions during revascularization.

The molecular signatures of atheroma compositions characterized by FLIm included macrophages, healed plaques, superficial calcification and fibrosis, in a reproducible manner, and these correlated with prior autopsy study findings.

Results showed that the mean plaque inflammation-FL was significantly greater in patients with ACS (7.59 nanoseconds) vs. those with CSA (6.46 nanoseconds). Additionally, the mean healed plaque-FL phenotype was distributed more prominently in segments of rapid disease progression (5.31 nanoseconds) vs. nonprogressive controls (4.81 nanoseconds) (p<0.001).

Notably, no major complications or adverse clinical events were reported during the seven-day follow-up.

The authors write that their unique imaging strategy enables the "comprehensive characterization of coronary plaques at risk" and "supports its potential role in the diagnosis and biological understanding of high-risk plaques." Although the system "has potential as a tool for personalized CAD diagnosis and treatment strategies," the authors acknowledge that "well-designed prospective multicenter clinical trials are warranted to determine whether an OCT-FLIm-guided individualized strategy can influence the clinical outcomes of patients with CAD."