Transcatheter aortic-valve replacement with a balloon-expandable valve in low-risk patients (PARTNER 3 Trial)

Reviewers

Elad Asher

@AsherElad

Interventional cardiologist / Cardiologist

Shaarey Zedek Medical Center - Jerusalem, Israel

Salvatore Brugaletta

@sbrugaletta

Interventional cardiologist / Cardiologist

Barcelona, Spain

Our Comment

This joint review is part of the PCRonline GLOBAL Journal Club Initiative by selected members of the EAPCI/PCR Journal Club and PCR NextGen, and is based on the underlying idea of “Bringing peers together, exchanging ideas, towards a common standard of care”.

Why this study – the rationale/objective?

Transcatheter aortic valve replacement (TAVR) has emerged as an alternative to surgical aortic valve replacement (SAVR) for the treatment of severe aortic stenosis (AS) among patients who are at intermediate or high risk for death with surgery. However, there is insufficient data regarding the comparison of the two procedures in patients who are at low risk.

How was it executed – the methodology?

Patients with severe AS and low surgical risk were randomly assigned to undergo either TAVR with transfemoral placement of a balloon-expandable valve or surgery. The primary end-point was a composite of all-cause death, stroke, or rehospitalization at 1-year. Both non-inferiority and superiority testing were performed.

What is the main result?

• A total of 1,000 patients from 71 centers underwent randomization. 
• Mean age was 73 years old, and mean Society of Thoracic Surgeons risk score was 1.9%. 
• The rate of the primary composite end point at 1 year was significantly lower in the TAVR group than in the surgery group (8.5% vs. 15.1%; hazard ratio, 0.54; 95% CI, 0.37 to 0.79; P = 0.001 for superiority). 
• At 30 days, TAVR resulted in a lower rate of stroke (0.6% vs. 2.4%, P = 0.02) and new-onset atrial fibrillation (5.0% vs. 39.5%, P<0.001) than surgery. 
• TAVR also resulted in a shorter index hospitalization and lower risk for re-hospitalization at 1-year follow-up (7.3% vs. 11%).
• There were no significant between-group differences in major vascular complications, new permanent pacemaker insertions, or moderate or severe paravalvular regurgitation.

Critical reading and the relevance for clinical practice

The principal findings of this study are that TAVR (of the balloon-expandable SAPIEN 3 system), was superior to surgery with regard to the primary composite endpoint of all-cause death, stroke, or re-hospitalization at 30 days and 1 year. Moreover, TAVR was associated with a significantly lower rate of new-onset atrial fibrillation at 30 days and a shorter index hospitalization and a more rapid improvement in the NYHA class and 6-minute walk-test distance than those who underwent surgery. 

These data are quite surprising for many of us, who were expecting only a no-inferiority of TAVR over surgery and it may open the door to use of TAVR in low-risk patients, especially involving patients in the decision-making process. 

Some points of the study should be carefully considered. 
First of all, these results only apply to a defined trial population, which excluded patients with poor transfemoral access, bicuspid aortic valves, or other anatomical or clinical factors that increased the risk of complications associated with either TAVR or surgery. 
Second, the PARTNER 3 trial does not address the issue of long-term structural valve deterioration and long follow-up is warranted. However, it is a matter of discussion if we need to wait for 10 years to have TAVR applied in low-risk patients. In this regard data coming from the 435 patients enrolled in a substudy with serial CT angiography, specifically looking to detect abnormalities in valve-leaflet function, may give us more details.
Last, but not least, cost-effectiveness analysis, which will come out later on, will add important data on the comparison between TAVR and conventional surgery.

Do you think that based on this trial, it is now time to update guidelines?

Read on the other major Late Breaking Trials presented at ACC 2019