No significant interaction was observed between the benefits of intravascular imaging and clinical presentation in the risk of target vessel failure (TVF), according to prespecified subgroup analysis of the RENOVATE-COMPLEX-PCI study. However, the analysis, published online Monday and in the May 27 issue of JACC: Cardiovascular Interventions, reported that a significant reduction of events was observed in patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI) optimization by intravascular imaging, suggesting that achieving optimized results according to intravascular imaging criteria is crucial, especially for patients with ACS. Jointly led by Sang Yoon Lee, MD, and Ki Hong Choi, MD, PhD, from Sungkyunkwan University School of Medicine, Seoul, South Korea, the team noted that while the benefits of intravascular imaging in PCI have been observed in previous studies, a question remains over whether such benefits may differ according to the clinical presentation among patients undergoing complex PCI. “There are substantial differences between acute coronary syndrome (ACS) and chronic coronary syndrome (CCS) with regard to the underlying pathophysiology, plaque vulnerability, benefits of revascularization treatment, and the risk of future adverse events,” noted the authors. “Theoretically, procedural optimization by intravascular imaging during complex PCI might have a greater influence on outcomes in patients with ACS than on those with CCS because of their vulnerable characteristics, such as increased thrombogenicity,” they said. Study details The authors performed a prespecified analysis of data from the RENOVATE-COMPLEX-PCI trial, in which they compared the outcomes between intravascular imaging vs. angiography guidance according to clinical presentation. Patients with complex coronary artery lesions were randomly assigned to undergo either intravascular imaging–guided PCI or angiography-guided PCI in a 2:1 ratio. Of 1,639 patients, 832 (50.8%) presented with ACS and 807 (49.2%) with CCS. The primary endpoint was TVF, which is a composite of cardiac death, target vessel–related myocardial infarction, or clinically driven target vessel revascularization. Secondary outcomes included individual components of the primary endpoint, TVF without procedure-related MI, a composite of cardiac death or target vessel–related MI, all-cause death, target lesion revascularization, repeat revascularization, definite stent thrombosis, and incidence of contrast-induced nephropathy, said Lee, Choi, and colleagues. Over an average follow-up of 2.1 years, TVF occurred in 76 patients in the intravascular imaging group and in 60 patients in the angiography group (7.7% vs 12.3%; hazard ratio [HR]: 0.64; 95% confidence interval [CI]: 0.45-0.89; P = 0.008), noted the authors. However, the analysis found no significant interaction between the use of intravascular imaging and clinical presentation with the risk of TVF (P for interaction = 0.19). Among patients with ACS, the risk of TVF was numerically lower in the imaging-guided PCI group than it was in the angiography-guided PCI group (10.4% [51/560] vs 14.6% [33/272]; HR: 0.74; 95% CI: 0.48-1.15; P = 0.18). “This difference was mainly attributed to a reduced risk of cardiac death in the imaging-guided PCI group (1.9% [8/560] vs 5.9% [11/272]; HR: 0.35; 95% CI: 0.14-0.86; P = 0.02),” reported the authors. Lee, Choi and colleagues concluded that the prespecified stratified subgroup analysis from RENOVATE-COMPLEX-PCI showed that there was no significant interaction between the benefits of intravascular imaging guidance and clinical presentation for the risk of TVF. “To warrant these findings, randomized clinical trials with an adequate sample size designed to compare the results between intravascular imaging guidance with optimization vs angiography guidance in patients with ACS are necessary,” they said. Intravascular imaging importance Writing in an accompanying editorial comment, Toshiki Kuno, MD, PhD, from the Albert Einstein College of Medicine, New York; Yuko Kiyohara, MD, from The University of Tokyo Hospital, and Shun Kohsaka, MD, PhD, from the Keio University School of Medicine, Tokyo, noted that alongside the advancements in intravascular imaging techniques, a notable shift in the indications for PCI has occurred during the same period. “The pathogenesis of acute coronary syndrome (ACS) also differs significantly from that of CCS; histologically, the vulnerability of coronary lesions in patients with ACS is more pronounced compared to those with CCS,” they said. “Given intravascular imaging’s capability to detect plaque vulnerability or burden (thereby informing decisions on stent coverage), this also raises the question of whether the treatment effect of intravascular imaging–guided PCI differs between ACS and CCS.” The editorialists noted that while no significant interaction was seen between the treatment effect of intravascular imaging and clinical presentation (ACS vs. CCS), interestingly, the analysis did demonstrate that stent optimization by intravascular imaging–guided PCI had lower events compared to unoptimization for patients with ACS, but not for those with CCS. “The present study offers valuable insights, demonstrating the advantageous effects of intravascular imaging–guided PCI over angiography-guided PCI with consistent outcomes between ACS and CCS populations. This is particularly relevant in light of the recent shift in PCI practice, increasingly favoring ACS over CCS patients,” they said. However, they noted that the adoption of intravascular imaging for PCI varies significantly by region and country (e.g., its usage is about 15% to 20% in the United States in contrast to over 80% in Japan). “Given that ACS proportions are epidemiologically higher in Western countries compared to East Asian countries, this study has global implications. It provides important information on the utility of intravascular imaging–guided PCI, narrowing the gap in intravascular imaging use,” they concluded. Sources: Lee SY, Choi KH, Kim CJ, et al. Impact of Intravascular Imaging-Guided Stent Optimization According to Clinical Presentation in Patients Undergoing Complex PCI. JACC Cardiovasc Interv 2024;17:1231-1243. Kuno T, Kiyohara Y, Kohsaka S. Intravascular Imaging–Guided Percutaneous Coronary Intervention With Adequate Stent Optimization. JACC Cardiovasc Interv 2024;17:1244-1245. Image Credit: Pijitra – stock.adobe.com