Key Points
- Both transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) procedures offer options for intervention in patients with aortic stenosis
- High-surgical risk has guided the use of a transcatheter approach, but data on its application in patients at low-surgical risk remains an area to be fully explored
- An update to the outcomes at 3-year follow up of the Evolut Low Risk Trial provide reassurance that TAVR is as safe as SAVR with respect to all-cause mortality or disabling stroke in low surgical risk patients
Both transcatheter and surgical aortic valve replacement offer evidence-based options for intervention in patients with aortic stenosis. Transcatheter approaches have transformed the management of patients with severe symptomatic aortic stenosis with this approach initially aimed at those patients deemed too high-risk for open heart surgery. Newer evidence has shown the transcatheter approach to be non-inferior to surgical replacement in patients with low-surgical risk in important outcomes such as all-cause mortality or disabling stroke, as seen in the 2-year analysis of The Evolut Low Risk Trial. At ACC 2023, the 3-year outcomes were presented in a presentation titled, “Transcatheter Versus Surgical Aortic Valve Replacement In Aortic Stenosis Patients At Low Surgical Risk: 3-year Outcomes From The Evolut Low Risk Trial”.
The 3-year analysis of the Evolut Low Risk Trial brings an update to the outcomes of a multinational, randomized, noninferiority clinical trial comparing the safety and efficacy of transcatheter aortic valve replacement (TAVR) with the self-expanding CoreValve compared with surgical aortic valve replacement (SAVR) in patients deemed to be at low risk for death at 30 days with surgery. In review, the inclusion criteria included those with severe symptomatic Eriksen notice, anatomy suitable for TAVR or SAVR, and a Society of Thoracic Surgeons Predicted Risk of Mortality score ≤ 3%. Patients excluded were those with contraindications for placement of a bioprosthetic study valve, bicuspid valve, or known hypersensitivity or contraindication to all anticoagulation/antiplatelet regimens. Patients (n = 1414) were randomly assigned in a 1:1 ratio to undergo either TAVR (n = 707 at 3-years) or SAVR (n = 624 at 3-years). The primary outcome was all-cause mortality or disabling stroke. Baseline characteristics between both groups were similar as previously reported with an average age of 74 years, 34% female participants, and normal left ventricular ejection fraction.
At three years, the primary outcome of all-cause mortality or disabling stroke after TAVR with the Evolut valve compared to favorably to surgery (7.4% vs 10.4% respectively). It is important to note that there was a 30% relative reduction in hazard ratios with a p-value that just missed significance of 0.051, with the overall absolute difference between arms remaining consistent throughout the three years. Within other outcomes measured, it was also emphasized that better valve hemodynamics in the TAVR group were seen at three years along with reassuringly low rates of valve thrombosis. Another highlight included significantly low levels of paravalvular regurgitation in the TAVR group with a degree of none/trace in nearly 80% of patients (p < 0.001). Higher rates of permanent pacemaker implantation where again seen with the TAVR group (p < 0.001); higher degrees of atrial fibrillation were seen with the SAVR group (p < 0.001). Importantly, KCCQ scores were similar at the three-year mark.
These findings continue to provide a reassuring trend, suggesting that patients at low surgical-risk do as well with TAVR compared with SAVR over 3 years of follow-up. Indeed, as noted by presenter Dr. John Forrest, “the excellent performance and durable outcomes out to three years in low risk patients affirm the role of TAVR with the Evolut valve in this [low-surgical] risk population”. Physicians and patients will have to wait for longer-term data to further evaluate the impact that “valve design, hemodynamics, new pacemakers, and other secondary endpoints will have on longer-term outcomes in low-risk patients.” Newer advances to valve technology and implantation technique are expected to further solidify these outcomes.