Limited antegrade subintimal tracking (LAST) is associated with lower procedural success, suggesting a limited role of LAST in contemporary percutaneous coronary intervention (PCI) for chronic total occlusions (CTO), according to a new study. Judit Karacsonyi, MD, PhD, of Abbott Northwestern Hospital, Minneapolis, and colleagues reported these findings in a manuscript published Monday online and in the Nov. 28 issue of JACC: Cardiovascular Interventions. Antegrade dissection and re-entry (ADR) is often used in CTO PCI and can be achieved using guidewires or a dedicated device. The following CTO lesion characteristics favor the use of dissection/re-entry: a well-defined proximal cap, a large-caliber distal vessel, no large branches within the CTO or at the proximal or distal cap, lack of good interventional collateral channels and a longer occlusion length. The LAST technique was developed to limit the length of dissection by re-entering immediately distal to the distal cap. The study analyzed 2,177 CTO PCIs performed using ADR in the PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) registry between 2012 and January 2022 at 39 centers. ADR was attempted in 1,465 cases (67.3%). Among antegrade re-entry cases, LAST was used in 163 (11.1%). The mean patient age was 65.2 years, and 85.8% were men. There was no significant difference in technical (71.8% vs 77.8%; P=0.080) and procedural (69.9% vs 75.3%; P = 0.127) success and major cardiac adverse events (1.84% vs 3.53%; P = 0.254) between LAST and non-LAST cases. However, on multivariable analysis, the use of LAST was associated with lower procedural success (odds ratio [OR]: 0.61; 95% confidence interval [CI]: 0.41-0.91). Primary LAST was associated with higher technical (76.4% vs 55.6%; P = 0.014) and procedural (75.6% vs 50.0%; P = 0.003) success and similar major adverse cardiac event (1.57% vs 2.78%; P = 0.636) rates compared with secondary LAST. The result of this study suggests that LAST should not be a first-choice strategy for antegrade re-entry. Antonio Colombo, MD from Humanitas University and IRCCS Humanitas Research Hospital, both in Milan, and colleagues wrote in an accompanying editorial, "As the word suggests, the LAST should remain the LAST." The editorialists suggest choosing different techniques for the treatment of CTO. However, they added that the findings of the study are not surprising because many techniques tend to be associated with higher failure rates when adopted as bailout rather than as the first technique. Also, in the study, there is limited follow-up available in less than one-third of cases and with a median duration of <3 months, and no difference in mortality, acute coronary syndrome, and target lesion revascularization events was observed between cases adopting or not adopting LAST. Sources: Karacsonyi J, Kostantinis S, Simsek B, et al. Use of the Limited Antegrade Subintimal Tracking Technique in Chronic Total Occlusion Percutaneous Coronary Intervention. JACC Cardiovasc Interv. 2022;15:2284–2293. Colombo A, Leone PP, Gasparini G, et al. As the Word Says, “LAST Should Be the Last”. JACC Cardiovasc Interv. 2022;15:2294 –2296. Image Credit: Belezapoy – stock.adobe.com