PARTNERS -3 and Evolute trials may change they way we treat aortic stenosis
It is a potential game-changer.
Two studies were released during the annual meeting of the American College of Cardiology today. They are the PARTNER-3 and Evolut trials, comparing transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR).
The aortic valve is the valve between the heart and main artery pumping blood to the rest of the body, the aorta. In many patients, this valve becomes extremely narrowed, or have stenosis, and this puts pressure on the heart causing it to fail. The condition is called aortic stenosis.
Traditionally, this could only be fixed with open heart surgery, where the chest would be cut open and the ribs split. Obviously, this type of surgery was associated with a lot of complications, including stroke and even death. More recently, a less invasive way of replacing the valve was developed: TAVR.
Up until this point, this less invasive way to replace the valve was usually reserved for the sickest patients, who would not tolerate open heart surgery. The question became, would this procedure be as good as surgery for those patients with lower surgical risk? It appears that the two studies above have answered this question in a resounding affirmative.
Here are the findings of the PARTNERS-3 study:
Among low-risk patients with aortic stenosis, TAVR was superior to SAVR at preventing death, stroke, or rehospitalization at 1 year. TAVR was also associated with a lower incidence of stroke and atrial fibrillation, and a shorter hospital length of stay compared with SAVR. There was a numerical increase in the need for new permanent pacemaker within 30 days in the TAVR group (6.5% with TAVR vs. 4.0% with SAVR); however, this difference was not statistically significant. Mild paravalvular aortic regurgitation occurred at a higher incidence in the TAVR group. The incidence of moderate to severe aortic regurgitation was rare (<1%) and similar between treatment groups.
The results of the Evolut study are below:
The results of this landmark trial indicate that TAVR with the self-expanding CoreValve Evolut valve is noninferior to SAVR for the primary endpoint of mortality/disabling stroke at 24 months for the treatment of severe symptomatic aortic stenosis in low-risk patients (median STS PROM 1.9%). Disabling strokes remained high in the SAVR arm over 2 years of follow-up. Permanent pacemaker and moderate to severe paravalvular leak were higher with TAVR at 30 days, while new-onset atrial fibrillation, acute kidney injury, and severe bleeding were higher in the SAVR arm. Valve performance at 2 years was similar between the two strategies, with lower mean gradients and higher effective orifice areas with TAVR.
Like I said above, this is a potential game changer. Here is what the ACC said on its website:
This is a landmark trial in this field. Paired with the results of the PARTNER 3 trial, these findings suggest that low surgical risk patients do as well and perhaps even better with TAVR compared with SAVR over 2 years of follow-up. Long-term follow-up is going to be essential to understand long-term performance and the risk of subclinical leaflet thrombosis and structural valve degeneration. If approved by the FDA, it will open up TAVR as a treatment option to a much larger pool of patients with aortic stenosis in the United States.
Many patients can go home after one or two days with this less invasive aortic valve replacement surgery option, as opposed to several days in the hospital after open heart surgery. And as the studies show, this procedure may even be safer than surgery. This is pretty huge.
Now, the transcatheter approach is not without its own complications: both studies showed an increase in valve leakage, and one study showed more patients needed permanent pacemakers. Furthermore, the jury is still out on whether these initial good outcomes are sustainable over the long term.
That said, if this procedure gets approved by the FDA for those patients with aortic valve disease that are healthier, this may change the whole standard of care of treating aortic stenosis, with many implications on both patients and hospitals. Quite exciting, and we will see what the future holds.
The opinions expressed in this post are my own and do not reflect those of my employer or the organizations with which I am affiliated.