New insights from a multicenter European study demonstrate that intravascular ultrasound (IVUS) can safely and effectively guide decisions to avoid unnecessary coronary stenting during transcatheter aortic valve replacement (TAVR). The investigation suggests that the technique is both feasible and safe for coronary artery obstruction (CAO), one of the most feared complications of TAVR, especially in valve-in-valve procedures. Until now, the decision to place a chimney stent has relied heavily on angiographic interpretation, which lacks precision. Chimney stenting “Our study shows that IVUS imaging after valve implantation was feasible and safe in 100% of cases,” said the paper’s authors, led by Mattia Lunardi, MD, PhD, from the University of Verona in Italy. “Most importantly, IVUS allowed us to safely defer chimney stenting in 63% of cases previously considered high-risk based on standard imaging.” Among 32 enrolled patients (40 vessels), 2 experienced sudden CAO requiring urgent chimney stenting. IVUS was feasible and safe in all remaining cases (38 vessels). On the basis of IVUS, chimney was deferred in 24 of 38 cases (63%; 95% confidence interval [CI]: 50%-78.9%). After a median follow-up period of 366 days (Q1-Q3: 119-780 days), major adverse cardiovascular and cerebrovascular events did not differ between patients receiving stents and those deferred (1 of 16 [6.2%] vs 1 of 16 [6.2%]; 95% CI: 0%-15.6%; P=0.958) IVUS benefits “Angiography often gives a false sense of security or prompts unnecessary stenting,” said the paper’s authors. “IVUS provided detailed, cross-sectional images that gave us real insight into the relationship between the displaced leaflet and the coronary ostium.” Writing in an accompanying editorial, Jaffar M. Khan PhD from St. Francis Hospital and Heart Center in Roslyn, New York, discusses the challenges of predicting coronary obstruction during TAVR. According to Dr Khan, current methods had "important limitations," leading to a lack of "uniformity in practice." He went onto state that while aortic cine angiography could be helpful in assessing the relationship between valve leaflets and coronary arteries, particularly in borderline cases to determine the height of bioprosthetic valve posts, it had few objective measurements. Dr. Khan advocated for wider adoption of intravascular ultrasound (IVUS), stating that its use "should be encouraged" and congratulated the investigators for "paving the way for wider use of this technique." Methodology The ICARO study was a prospective, multicenter, observational trial that enrolled 32 parents (56.3% female,43.7% male) with a median age of 83 years (interquartile range: 79–86). Coronary protection with guidewire and undeployed stent was implemented before THV deployment. After TAVR, IVUS imaging was performed in the coronary arteries to assess ostial patency. The primary endpoint was a composite of successful IVUS imaging of the at-risk coronary artery after TAVR and an absence of complications such as dissection, perforation, thrombosis or flow impairment during IVUS. Sources: Lunardi M, Pesarini G, Cubich M, et al. Intravascular Ultrasound Assessment of Coronary Arteries at High Risk for Obstruction Following TAVR: The ICARO Study. JACC Cardiovasc. Interv. 2025;18: 1147–1160. Jaffar M. Khan, PhD. All You Need to Know About TAVR Coronary Obstruction and Why IVUS Is a Good Idea. JACC Cardiovasc. Interv. 2025;18:1161–1162. Image Credit: Nadzeya– stock.adobe.com