A new report outlines the discrepancies in the techniques used to measure virtual valve-to-coronary distance during transcatheter aortic valve replacement (TAVR) in prediction the risk of coronary obstruction. Rim N. Halaby, MD, from the National Institutes of Health, Bethesda, Maryland, and colleagues, reported these data in a brief report published online in JACC: Cardiovascular Interventions. Coronary obstruction is a potential complication of TAVR, and it can direct or indirect. In order to potentially predict coronary obstruction, operators use computed tomography (CT) to measure the valve, sinuses, sinotubular junction and coronary ostia. Patients are at greater risk for obstruction if the virtual valve-to-coronary distance (VTC) <4 mm, when the leaflet is higher than the coronary ostium. The best technique for measuring the VTC, however, is still up for debate. Investigators at Edwards Lifesciences (Irvine, California) and Medtronic (Minneapolis) typically measure to the coronary ampulla, the authors of this report wrote. Investigators in this study estimate that the ampulla overstate patients’ risk of coronary obstruction and recommend measuring to the coronary ostium. In this study, the ampulla approach was compared with the coronary ostium approach in patients screened for the TELLTALE (NHLBI Transmural Electrosurgery Leaflet Traversal and Laceration Evaluation) pivotal trial. The TELLTALE trial looked at the use of the BASILICA (bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction) electrosurgery system in this patient population. Investigators had analyzable data from 154 patients with 610 measurements. Paired VTC measurements were available for 305 coronary arteries (right=151, left=154) of 90 patients enrolled. Paired differences, with the ampulla subtracted from the ostium, were presented. The ostial VTC was consistently greater than or equal to ampulla VTC (median paired difference=0.6 mm, Q1-Q3: 0.0-0.9mm; 95% CI=0.5-0.7 mm; p<0.001). No proportional bias was observed. Concordance was also high, which demonstrated that there was consistent difference between the ostial VTC and ampulla VTC. Covariates including age, body surface area (BSA), sex, left versus right, target vessel versus nontarget vessel and native versus bioprosthetic did not make a difference in the ostium-ampulla variation. Only 29% of measurements were identical between the two. The ampulla method ended up re-classifying 44 of the 305 arteries to “high risk” instead of “not high risk.” Overall, the investigators in this brief report concluded that the ampulla method of measuring VTC was more conservative than the coronary ostium method. Because of this, more patients were classified as “at-risk” for coronary obstruction after TAVR. “One practical implication is that actual VTC distances were narrower in the TELLTALE electrosurgical BASILICA pivotal clinical trial than in the ShortCut mechanical BASILICA pivotal clinical trial, despite similar measured values (3.2 ± 0.6 mm vs 3.3 ± 1.2 mm), suggesting a higher risk for obstruction,” the authors concluded. “Using this more strict ostial VTC measurement technique, TELLTALE-BASILICA prevented leaflet induced transcatheter aortic valve replacement-associated coronary obstruction.” Source: Halaby RN, Bruce CG, Khan JM, et al. Ostial vs ampulla techniques to measure virtual valve-to-coronary distance in TAVR coronary obstruction risk. JACC Cardiovasc Interv. 2026 January. Doi/10.1016/j.jcin.2025.10.064 Image Credit: fizkes – stock.adobe.com