The Portico IDE study has found that 30-day safety and one-year effectiveness outcomes of a novel self-expanding transcatheter aortic valve implantation (TAVI) system for patients with severe aortic stenosis (AS) at high or extreme-risk for surgery was noninferior to contemporary FDA-approved TAVI systems available in the USA.
The findings were presented today at the 31st Transcatheter Cardiovascular Therapeutics scientific symposium (TCT 2019; 25–29 September, San Francisco, USA) by Gregory P Fontana (Los Robles Hospital & Medical Center, Thousand Oaks, California, USA).
PORTICO was a prospective, multicentre, controlled, open-label, noninferiority intention-to-treat evaluation of the safety and effectiveness of the Portico TAVI system (Abbott) compared with FDA-approved and commercially available TAVI systems. Between May 2014 and June 2019, 750 patients from 69 sites were randomised 1:1 to each group. Baseline characteristics were balanced for both groups; mean age was 83.3 years (±7.3 years), 52.7% were female, and the mean Society of Thoracic Surgeons (STS) score was 6.5%. Procedural success was comparable between groups (96.5% for Portico vs. 98.3% for commercially available TAVI).
The study met both the prespecified primary safety composite endpoint (all-cause mortality, disabling stroke, life threatening bleeding requiring blood transfusion, acute kidney injury requiring dialysis, or major vascular complications at 30 days, 13.8% vs 9.6%; p noninferiority=0.03) and the primary effectiveness composite endpoint (all-cause mortality or disabling stroke at one-year, 14.9% vs 13.4%, p noninferiority =0.006).
The study also included a separate cohort of 100 patients who underwent Portico valve implantation using the FlexNav Delivery System. The primary safety endpoint for the FlexNav cohort was the major vascular complication rate at 30 days. This cohort demonstrated no deaths or strokes, and low rates of major vascular complications (7%) and new permanent pacemaker implants (14.6%), as well as a safety profile comparable with the commercially available valve group in the randomised study (8% vs 9.6%).
Major vascular complications occurred with greater frequency in Portico valve group, driving the difference in the safety profile, with an improvement in the safety and effectiveness in the Portico valve group in the second half of the trial. The Portico valve was associated with improved haemodynamics (larger valve areas and smaller gradients) and a higher rate of moderate paravalvular leak compared to commercial valves.
Fontana outlined “some quite notable” limitations of the study: “The actual performance of both groups was better than the assumed rates, due in part to an overall improvement in TAVI technology, operator experience, and better patient selection.” In addition, over the enrolment period of three and a half years, multiple valve types and design iterations were introduced in the commercial valve group “resulting in a heterogenous control group”, and the implant experience with the Portico valve was disproportionate to that with commercial valves, with a median of five implants per site, and only six sites with >20 implants “suggesting that most sites may not have moved past the learning curve with the device”. He added, that despite the impressive results with the FlexNav Delivery System, the cohort consisted of a relatively small, non-randomised group.
Fontana said that the findings suggest the Portico valve may provide an additional transcatheter heart valve type to treat high and extreme risk patients with severe aortic stensosis, and revealed that the next-generation valve with design modifications to reduce paravalvular leak is currently being tested in clinical trials.
