Chimney Stenting versus BASILICA for prevention of coronary obstruction in high-risk transcatheter aortic valve implantation

Background Coronary obstruction (CO) is an uncommon but critical complication of transcatheter aortic valve implantation (TAVI). In anatomically high-risk patients, two commonly used preventive approaches are coronary stent-based protection via chimney stenting, and leaflet modification via Bioprosthetic or Native Aortic Scallop Intentional Laceration to Prevent Iatrogenic Coronary Artery Obstruction (BASILICA). Contemporary observational data comparing these strategies remains inconsistent. We performed a systematic review and meta-analysis to consolidate the existing evidence, comparing outcomes between BASILICA and chimney stenting in high-risk TAVI. Methods This study was conducted in accordance with PRISMA guidelines. PubMed, EMBASE, Web of Science, and Cochrane databases were searched until February 20, 2026 for all studies enrolling TAVI patients undergoing preventive BASILICA or chimney stenting. Technical success was defined as procedure completion without clinically significant ostial CO. The primary endpoint was early all-cause mortality (in-hospital and at 30 days). The secondary outcome was the composite 1-year major adverse cardiovascular events (MACE), defined as death, myocardial infarction, stroke, or unplanned target lesion revascularisation. Odds ratios (OR) were pooled using a random-effects model. Subgroup and sensitivity analyses explored heterogeneity. Results A total of 13 studies were included (424 patients undergoing BASILICA and 389 chimney stenting). Patients undergoing BASILICA had higher baseline preprocedural risk of CO, as indicated by smaller sinus of Valsalva height (14.9 ± 3.1 mm vs 19.3 ± 3.0 mm ; P < 0.001) and diameter (26.7 ± 3.0 mm vs 28.0 ± 5.1 mm ; P < 0.001), smaller left main coronary height (7.1 ± 2.3 mm vs 9.2 ± 3.9 mm ; P < 0.001), more valve-in-valve procedures (277/356 (77.8%) vs 142/249 (57.0%), p<0.001) and shorter virtual transcatheter distance (3.6 ± 1.0 mm vs 4.0 ± 1.9 mm ; P < 0.001). Technical success was 97.4% and 87.9% in chimney and BASILICA groups, respectively (p < 0.001). Planned BASILICA was converted to bailout coronary stenting in 20/424 (4.7%) of cases. In the pooled analysis, there was no statistically significant difference in MACE at 1-year between the chimney and BASILICA strategies (OR 0.92, 95% CI 0.42–2.01), despite a trend towards increased early all-cause mortality (8.3% vs 4.8%, p = 0.07), major bleeding (9.3% vs 6.3%, p = 0.56), paravalvular leak and acute kidney injury (8.2% vs 4.9%, p = 0.36) in the chimney group. Conclusion Chimney stenting and BASILICA demonstrate comparable 1-year efficacy in preventing clinically significant CO in high-risk TAVI. Despite trend towards increased mortality, AKI and paravalvular leak in the chimney stenting group, there was insufficient evidence to demonstrate superiority of either strategy. Procedural risk profile, operator expertise, and long-term coronary access considerations may guide selection.30-Day Mortality: BASILICA vs ChimneyFor image description, please refer to the figure legend and surrounding text.