Long-term clinical outcomes of acute myocardial infarction based on a center's experience with IVUS in the contemporary drug-eluting stent era

Abstract Introduction Intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) is recognized for improving patient prognosis. However, how a center's experience with IVUS affects clinical outcomes remains unclear. Purpose This study aims to elucidate the impact of a center's expertise in IVUS on clinical outcomes, emphasizing the value of institutional experience. Methods In this retrospective cohort study from the Korean AMI Registry (KAMIR), we analyzed 9,752 patients diagnosed with acute myocardial infarction (AMI) who underwent intervention with second-generation drug-eluting stents. The primary outcome was major adverse cardiovascular events (MACE) at 3 years, defined as the composite of all-cause deaths, any myocardial infarction, and any coronary revascularization. The secondary outcome was target-lesion failure (TLF), defined as the composite endpoint of all cardiac deaths, target vessel myocardial infarction, and ischemia-driven target lesion revascularization at 3 years. Results In this study, the median frequency of IVUS usage across 20 institutions was 10.3%. Hospitals were categorized as centers with extensive experience in IVUS or those with limited experience, based on the median frequency of IVUS usage. In centers with extensive experience in IVUS, IVUS-guided PCI consistently showed a reduction in MACE (18.5% vs. 15.3%, p=0.016) and TLF (8.3% vs. 6.3%, p=0.039) within propensity-score matched populations. Furthermore, multivariate Cox regression analysis revealed that IVUS-guided PCI was associated with decreased risks of MACE (HR 0.80, 95% CI [0.69-0.93], p=0.003) and TLF (HR 0.75, 95% CI [0.59-0.95], p=0.01). However, from propensity matched population in centers with limited experience in IVUS, there were no significant reductions in the incidences of MACE (18.6% versus 15.7%, p=0.422) and TLF (10.4% versus 8.9%, p=0.644). Conclusion This comprehensive, nationwide cohort study shows that outcomes of IVUS-guided PCI are more favorable in centers with extensive IVUS experience compared to those with limited experience. These results indicate that the clinical advantages of IVUS-guided PCI are more pronounced in centers with extensive experience than in those with limited experience.