Hot Line 4: Which imaging modalities are best to guide PCI?
27 Aug 2023
A feast for interventionists and imagers – Hot Line 4 saw the presentation of three trials comparing different modalities and ended with a meta-analysis of the evidence.
As presented by Doctor Ziad Ali (DeMatteis - St Francis, USA), the ILUMIEN IV trial investigated whether optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) is superior to angiography-guided PCI for minimum stent area and target vessel failure in complex cases. The trial enrolled 2,487 patients with medication-treated diabetes and/or complex lesions (defined as NSTEMI, late-presenting STEMI [>24 hours], stent length ≥28 mm, severe calcification, two-stent bifurcation, in-stent restenosis or chronic total occlusion). The minimum stent area achieved was larger in the OCT-guided group than in the angiography-guided group (5.72 ± 2.04 versus 5.36 ± 1.87 mm2; p<0.001). There were also fewer angiographic complications and a nearly two-thirds reduction in stent thrombosis with OCT during 2-year follow-up (0.5% versus 1.4%). However, there was no difference in the 2-year rate of target vessel failure with OCT versus angiography (7.4% versus 8.2%; p=0.45).
Doctor Lene Nyhus Andreasen (Aarhus University Hospital - Aarhus, Denmark) then discussed the OCTOBER trial, described as ‘the first adequately powered clinical trial to examine whether routine use of OCT during PCI of complex bifurcation lesions improves clinical outcomes compared to standard practice with angiographic guidance and optional use of intravascular ultrasound (IVUS) in left main bifurcations.’ Across 1,201 patients with complex bifurcation lesions, the primary endpoint of major adverse cardiac events (cardiac death, target lesion MI and ischaemia-driven target lesion revascularisation) occurred less frequently with OCT than angiography (10.1% versus 14.1%; hazard ratio [HR] 0.70; 95% CI 0.50 to 0.98, p=0.035). There were no apparent differences in procedural safety, but the volume of contrast and the procedure time both increased with OCT compared with angiography. In the angiography-guided arm, IVUS was also used in approximately one in five cases, which “reflects current clinical practice for complex PCI procedures in many centres,” according to Dr. Andreasen, who concludes, “The results suggest that routine use of structured OCT guidance during PCI of complex bifurcation lesions should be considered to improve prognosis.”
As described by Professor Duk-Woo Park (Asan Medical Center - Seoul, Republic of Korea), the pragmatic OCTIVUS trial was a head-to-head comparison of OCT- and IVUS-guided PCI conducted in 2,008 patients with a broad range of coronary artery lesions after diagnostic coronary angiography. After 1 year, the primary endpoint of death from cardiac causes, target vessel MI or ischaemia-driven target vessel revascularisation occurred in 2.5% of patients in the OCT-guided PCI group and in 3.1% in the IVUS-guided PCI group (p<0.001 for non-inferiority). The incidence of contrast-induced nephropathy was similar in the OCT and IVUS groups (1.4% versus 1.5%, respectively), but major procedural complications were lower with OCT (2.2% versus 3.7%; p=0.048). The total amount of contrast used was higher with OCT compared with IVUS (p<0.001), but the total PCI time was shorter in the OCT group (p<0.001).
Finally, Professor Gregg Stone (Icahn School of Medicine at Mount Sinai - New York, USA) discussed a real-time updated network meta-analysis, which integrated data from the ILUMIEN IV and OCTOBER trials with prior studies – 20 trials and 12,428 patients in total – to examine the effects of intravascular imaging (IVUS and OCT) versus angiography guidance. IVUS or OCT guidance resulted in a 31% reduction in target lesion failure compared with angiography, when target lesion failure was defined as cardiac death, target vessel MI or target lesion revascularisation. Regarding secondary outcomes, IVUS or OCT resulted in reductions in cardiac death by 46%, target vessel MI by 20%, target lesion revascularisation by 29%, and stent thrombosis by 52% compared with angiography guidance. There were also significant reductions in all-cause death and all MI with IVUS or OCT. The outcomes were similar for OCT and IVUS when compared individually against angiography and when compared to each other. “The results of this network meta-analysis emphasise the importance of physicians using intravascular imaging with either OCT or IVUS to optimise stent outcomes and improve the long-term prognosis of their patients,” says Prof. Stone, as a fitting summary of Hot Line 4.