Chimney stenting for coronary protection in high-risk TAVR patients

Jhonathan Uribe-Gonzalez, Department of Interventional Cardiology, Hospital de Cardiología, Centro Médico Nacional Siglo XXI; Department of Interventional Cardiology, ABC Medical Center; Mexico City, Mexico
Humberto Uribe-Ramos, Department of Interventional Cardiology, Cardiology Hospital, Centro Médico Nacional Siglo XXI; 2School of Medicine, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
Jhonathan Zamudio-Lopez, Department of Interventional Cardiology, Cardiology Hospital, Centro Médico Nacional Siglo XXI; 2School of Medicine, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
Efrain Arizmendi-Uribe, Department of Interventional Cardiology, Hospital de Cardiología, Centro Médico Nacional Siglo XXI, Mexico City, Mexico
Joel Estrada-Gallegos, Department of Interventional Cardiology, Hospital de Cardiología, Centro Médico Nacional Siglo XXI, Mexico City, Mexico
Abiahi Lucas-Hernández, Department of Interventional Cardiology, Cardiology Hospital, Centro Médico Nacional Siglo XXI; 2School of Medicine, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico

Background: Acute coronary obstruction (ACO) is a rare but potentially fatal complication of transcatheter aortic valve replacement (TAVR). The chimney stenting technique (CST) has emerged as a preventive strategy in patients with high-risk anatomy. Objectives: To evaluate the safety and effectiveness of prophylactic CST in high-risk patients undergoing TAVR with long-term follow-up. Methods: We conducted a case series of six high-risk patients (2.1% of 275 TAVR procedures) treated at the Hospital de Cardiología, Centro Médico Nacional Siglo XXI, Mexico, between 2020 and 2024. Patients had anatomical features predictive of ACO and underwent prophylactic CST. Data on anatomy, procedural technique, and clinical outcomes were analyzed. Results: All patients had high-risk anatomical features such as low coronary ostia height, narrow Valsalva sinuses, bulky leaflet calcification, or ostial coronary lesions. Right radial access and 7 Fr guiding catheters were predominantly used. Balloon-expandable valves and everolimus-eluting stents ≥4.0 mm were deployed. One case of stent migration was successfully retrieved. Two patients experienced mild paravalvular leak. No permanent pacemaker implantation was required. After a mean follow-up of 3.7 years, no major adverse cardiac events were reported. Conclusion: Prophylactic CST appears to be a safe and effective coronary protection strategy during TAVR in patients with high-risk anatomy. Our single-center experience shows favorable long-term outcomes, although additional research is needed to assess very-long-term durability.

Keywords: Transcatheter aortic valve replacement. Acute coronary obstruction. Chimney technique. Coronary protection. Transcatheter valve.