Background. The CONFIDENCE registry was initiated to gather real-world clinical outcomes and device performance to enhance the totality of evidence describing the use of the Portico valve for the treatment of severe symptomatic aortic stenosis.

Methods. The CONFIDENCE registry is a contemporary, prospective, non-randomized, observational, multicenter registry of 1001 subjects clinically indicated for implantation of a Portico transcatheter aortic heart valve. This registry was initiated to assess outcomes from experienced implanters of the Portico valve, using either the first-generation delivery system or the newer FlexNav delivery system in high and extreme risk patients. Adverse events are adjudicated by an independent Clinical Events Committee according to VARC-2 definitions and echocardiograms are evaluated by an independent core laboratory at 30 days.

Results. 1001 subjects were enrolled between October 2018 and July 2021 at 28 sites across 9 countries (Europe and Australia). The mean age was 82.0 years and 62.5% were female. The mean STS score was 4.4% and 45.9% had 1 or more frailty factors contribute to the subject’s surgical risk score. The mean native aortic annulus was 23.6 mm, with 35.9% subjects implanted with a 23- or 25-mm valve. A single Portico valve was successfully implanted in 97.5% of subjects.

At 30 days, the event rates for all-cause and cardiovascular mortality were 2.6% and 2.1%. The event rates for disabling and non-disabling stroke were 1.8% and 1.1%. The permanent pacemaker insertion rate at 30 days among the pacemaker naïve population was 19.0%. Outcomes were consistent across delivery system usage, but there was numerically lower all-cause (2.0% vs. 3.2%) and cardiovascular mortality (1.2% vs. 3.0%) in the FlexNav cohort at 30 days.

Valve hemodynamics demonstrated an improvement of mean transvalvular gradient and aortic valve area from 42.8 mmHg and 0.7 cm² to 7.1 mmHg and 1.8 cm², respectively, at 30 days. Paravalvular aortic regurgitation was mild or less in 97.9% of subjects, with no severe cases as assessed by the core laboratory.

Clinical improvement metrics at 30 days demonstrated sustained improvement amongst paired subjects. In a paired analysis of 883 subjects, 70.7% improved at least one NYHA class from baseline to 30 days. 

Conclusions. Outcomes demonstrate low rates of adverse events and excellent hemodynamic performance at 30 days, supporting the continued use of the Portico transcatheter heart valve for the treatment of severe symptomatic aortic stenosis.