Optical coherence tomography- vs angiography-guided coronary stent implantation in calcified lesions: the ILUMIEN IV trial

The large-scale, randomized ILUMIEN IV trial was examined to determine whether procedural guidance with optical coherence tomography (OCT) during percutaneous coronary intervention (PCI) of angiographically calcified lesions improves outcomes.

Patients with a single PCI target lesion were included in the present analysis. The presence of none, mild, moderate or severe lesion calcification was determined by an angiographic core laboratory. The primary imaging endpoint was the post-PCI minimal stent area (MSA) assessed by OCT. The primary clinical endpoint was 2-year target-vessel failure (TVF), a composite of cardiac death, target-vessel myocardial infarction (TV-MI), or ischaemia-driven target-vessel revascularization.

In the overall population (n = 2114), there was a significant interaction between the effect of randomization to OCT guidance vs angiography guidance in lesions with moderate/severe calcification (n = 1082) vs no/mild calcification (n = 1032) on the 2-year rate of TVF (Pinteraction = .01). The post-PCI MSA in moderately and severely calcified lesions was larger with OCT guidance (n = 544) compared with angiography guidance (n = 538) (5.57 ± 1.86 mm² vs 5.33 ± 1.78 mm²; P = .03). In the moderate/severe calcified lesion cohort, TVF within 2 years occurred in 35 patients with OCT guidance and in 51 patients with angiography guidance (6.8% vs 9.7%; adjusted hazard ratio [aHR] 0.62; 95% confidence interval [CI] 0.40–0.96), whereas there was no significant difference in TVF in the no/mild calcified lesion cohort (7.7% vs 5.2%; aHR 1.48; 95% CI 0.90–2.44) (Pinteraction = .01). In moderately/severely calcified lesions, OCT-guided PCI also reduced the 2-year rates of serious major adverse cardiac events (2.8% vs 4.7%; aHR 0.49; 95% CI 0.25–0.95; P = .03), TV-MI (1.9% vs 4.0%; aHR 0.36; 95% CI 0.17–0.79; P = .01), and stent thrombosis (0.2% vs 1.5%; aHR 0.11; 95% CI 0.01–0.89; P = .04) compared with angiography-guided PCI.

In the ILUMIEN IV trial, OCT-guided PCI in patients with angiographically determined moderately or severely calcified lesions reduced the 2-year rate of TVF compared with angiography-guided PCI, an effect that was not seen in patients with lesions with no or mild angiographic calcium.