Feasibility of Transcatheter Aortic Valve Implantation in Patients With Very Severe Aortic Stenosis

Background: Very severe aortic stenosis (AS) has a poor prognosis even in asymptomatic patients, and asymptomatic very severe AS is a Class IIa indication for aortic valve replacement, although the safety and effectiveness of transcatheter aortic valve implantation (TAVI) for very severe AS is not well-established. Methods and Results: This study included 366 patients undergoing TAVI at a single center, with 85 and 281 patients in the very severe AS (peak velocity >= 5 m/s or mean pressure gradient (PG) >= 60 mmHg) and severe AS groups, respectively. Procedural and clinical outcomes at 1-year follow-up were compared between groups. The calcium scores were significantly higher in the very severe AS group (2,864.5 vs. 1,405.8 arbitrary units [AU] (P<0.001). Although the patient-prosthesis mismatch rate was higher in the very severe AS group (38.3% vs. 25.7%; P=0.029), there was no significant difference in the early safety and clinical efficacy between the groups (16.5% vs. 17.1% and 12.0% vs. 18.9%, respectively). Similarly, there was no significant difference in all-cause mortality at 1 year (4.8% vs. 9.8%). Conclusions: Despite a higher incidence of prosthesis-patient mismatch in those with very severe AS, the procedural and clinical outcomes were comparable to those in patients with severe AS. TAVI may be a reasonable treatment option for very severe AS.