The use of optical coherence tomography (OCT) plus predefined algorithmic management achieved better stent implantation results than angiographic guidance when performing PCI in patients with calcified lesions according to the results of the CALIPSO trial published April 30 in JAMA Cardiology.

The prospective, open-label trial conducted at 12 sites in France randomized 143 patients with stable moderate to severe calcified coronary lesions on diagnostic coronary angiography to either OCT-guided PCI or angiography-guided PCI between December 2021 and June 2023. In the OCT cohort, a predesigned standardized management algorithm was used. For the final analysis, 134 patients were included (65 in the OCT group and 69 in the angiography group).

At baseline, the two groups were similar except that intravascular lithotripsy was used more often in the OCT group than the angiography group (46% vs. 12%), and the median age was 73 years and 19% were women.

Nicolas Amabile, MD, PhD, et al., reported that the primary endpoint of the minimal stent area (MSA) measured by OCT in both cohorts was larger in the OCT group than the angiography group (6.5 mm2 vs. 5.0 mm2).

Looking at secondary safety endpoints, there was no difference between the groups in periprocedural complications, contrast medium volume or procedure duration.

In the first randomized trial to compare these two strategies in this patient population, write the authors, and using an algorithm for plaque preparation, stent sizing and optimization, OCT-guided PCI resulted in significantly greater average stent expansion and lower malappositon. By improving the quality of stent implantation, the OCT-based strategy could improve clinical outcomes in a population with a high incidence of calcified stenoses.

The authors write, however, that "Whether this superiority, in terms of imaging endpoints, will translate into clinical benefit should be assessed in the future."

In an accompanying editorial comment, Marc-Andre D'Entremont, MD, and Sanjit S. Jolly, MD, MSc, write that "OCT itself does not improve clinical outcomes, but how the information changes management does. The pairing of OCT with a calcium management algorithm was likely the key to success in the CALIPSO trial and the optimal method to use OCT in calcified lesions." While this trial is an "essential first step in defining the role of OCT in calcified lesions," larger trials powered for clinical outcomes are needed to solidify its role as well as calcium modification therapies.