Evolut Surgical Replacement and Transcatheter Aortic Valve Implantation in Low Risk Patients - Evolut Low Risk

Contribution To Literature:

The Evolut Low Risk trial showed that TAVR was noninferior to SAVR for mortality/disabling stroke at 24 months for treatment of severe symptomatic aortic stenosis in low-risk patients.


Description:

The goal of the trial was to assess the safety and efficacy of transcatheter aortic valve replacement (TAVR) with the self-expanding CoreValve compared with surgical aortic valve replacement (SAVR) in low-risk patients.


Study Design

Patients were randomly assigned in a 1:1 ratio to undergo either TAVR (n = 725) or SAVR (n = 678). TAVR was performed with the self-expanding CoreValve Evolut in most cases; 22.3% received the third-generation Evolut PRO.

  • Total number of enrollees: 1,403
  • Duration of follow-up: 24 months
  • Mean patient age: 74 years
  • Percentage female: 35%

Inclusion criteria:

  • Severe symptomatic aortic stenosis
  • Anatomy suitable for TAVR or SAVR
  • Society of Thoracic Surgeons Predicted Risk of Mortality (STS PROM) score ≤3%

Exclusion criteria:

  • Contraindication for placement of a bioprosthetic valve
  • Bicuspid valve
  • A known hypersensitivity or contraindication to all anticoagulation/antiplatelet regimens

Other salient features/characteristics:

  • Median STS PROM score: 1.9%
  • Previous percutaneous coronary intervention: 13%
  • Previous coronary artery bypass grafting: 2.2%
  • Cerebrovascular disease: 11%
  • Peripheral artery disease: 8%
  • Mean left ventricular ejection fraction: 61%

Principal Findings:

The primary endpoint of all-cause mortality or disabling stroke for TAVR vs. SAVR at 24 months, was 5.3% vs. 6.7% (p < 0.05 for noninferiority, p > 0.05 for superiority).

Also at 2 years, all-cause mortality was 4.5% for TAVR vs. 4.5% for SAVR (p > 0.05). Disabling stroke was 1.1% for TAVR vs. 3.5% for SAVR (p < 0.05).

Secondary outcomes, all for TAVR vs. SAVR:

  • All-cause mortality or disabling stroke at 30 days: 0.8% vs. 2.6% (p < 0.05)
  • All-cause mortality at 30 days: 0.5% vs. 1.3% (p > 0.05)
  • All strokes at 30 days: 3.4% vs. 3.4% (p = 1.0)
  • Death, disabling stroke, life-threatening bleeding, major vascular complications, stage 2/3 kidney injury: 5.3% vs. 10.7% (p < 0.05)
  • All strokes at 30 days: 3.4% vs. 5.6% (p < 0.05)
  • Major vascular complication at 30 days: 3.8% vs. 3.2% (p > 0.05)
  • Life-threatening or disabling bleeding at 30 days: 2.4% vs. 7.5% (p < 0.05)
  • New permanent pacemaker at 30 days: 17.4% vs. 6.1% (p < 0.05)
  • Moderate to severe paravalvular leak: 3.5% vs. 0.5% (p < 0.05)
  • Atrial fibrillation at 30 days: 7.7% vs. 35.4% (p < 0.05)
  • Primary endpoint at 1 year: 2.9% for TAVR vs. 4.6% for SAVR (p > 0.05)
  • Mean aortic gradient at 1 year: 8.6 mm Hg for TAVR vs. 11.2 mm Hg for SAVR (p < 0.05)
  • Mean effective orifice area at 1 year: 2.3 for TAVR vs. 2.0 for SAVR (p < 0.05)
  • Mean Kansas City Cardiomyopathy Questionnaire (KCCQ) change from baseline at 30 days: 20.0 for TAVR vs. 9.1 for SAVR (p < 0.05)

Interpretation:

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.

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.

References:

Popma JJ, Deeb GM, Yakubov SJ, et al., on behalf of the Evolut Low Risk Trial Investigators. Transcatheter Aortic-Valve Replacement With a Self-Expanding Valve in Low-Risk Patients. N Engl J Med 2019;380:1706-15.

Editorial: Otto CM. Informed Shared Decisions for Patients With Aortic Stenosis. N Engl J Med 2019;380:1769-70.

Presented by Dr. Michael J. Reardon at the American College of Cardiology Annual Scientific Session (ACC 2019), New Orleans, LA, March 17, 2019.

Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Geriatric Cardiology, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Valvular Heart Disease, Atrial Fibrillation/Supraventricular Arrhythmias, Aortic Surgery, Cardiac Surgery and Arrhythmias, Cardiac Surgery and Heart Failure, Cardiac Surgery and VHD, Acute Heart Failure, Interventions and Structural Heart Disease

Keywords: ACC Annual Scientific Session, ACC19, Acute Kidney Injury, Aortic Valve Stenosis, Atrial Fibrillation, Cardiac Surgical Procedures, Geriatrics, Heart Failure, Heart Valve Diseases, Heart Valve Prosthesis, Pacemaker, Artificial, Stroke, Transcatheter Aortic Valve Replacement, Vascular Diseases


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