Reinterventions After CoreValve/Evolut Transcatheter or Surgical Aortic Valve Replacement for Treatment of Severe Aortic Stenosis

Impact of Transcatheter or Surgical Aortic Valve Performance on 5-Year Outcomes in Patients at ≥ Intermediate Risk

BACKGROUND

The incidence and clinical importance of bioprosthetic valve dysfunction (BVD) in patients undergoing supra-annular, self-expanding transcatheter aortic valve replacement (TAVR) or surgery is not well understood.

OBJECTIVES

The purpose of this study was to evaluate the 5-year incidence and clinical outcomes of BVD in patients undergoing CoreValve/Evolut TAVR or surgery.

METHODS

This post hoc analysis pooled data from the U.S. High Risk Pivotal (n = 726) and SURTAVI (n = 1,618) randomized controlled trials (RCTs), the Extreme Risk Pivotal trial (n = 608), and CoreValve Continued Access Study (n = 2,654). The primary endpoint was the incidence of BVD through 5 years from the RCTs. The association of BVD with 5-year clinical outcomes was evaluated in the pooled RCT and non-RCT populations.

RESULTS

Of 5,606 patients evaluated, 3,070 (54.8%) were men, and the mean age was 82.2 ± 7.4 years. A total of 2,344 RCT patients, including 1,227 who received TAVR and 1,117 who received surgery, and 3,262 non-RCT TAVR patients were included. The rate of BVD was lower in RCT patients undergoing CoreValve/Evolut TAVR compared with surgery (9.7% vs 15.3%; subdistribution HR: 0.57; 95% CI: 0.45-0.73; P < 0.001). In the pooled RCT and non-RCT cohort, BVD was associated with increased 5-year all-cause mortality (HR: 1.49; 95% CI: 1.32-1.68; P < 0.001), cardiovascular mortality (HR: 1.76; 95% CI: 1.52-2.03; P < 0.001), and hospitalization for valve disease or worsening heart failure (HR: 1.48; 95% CI: 1.23-1.78; P < 0.001).

CONCLUSIONS

Five-year valve performance was significantly better after CoreValve/Evolut TAVR compared with surgery. Development of BVD in TAVR and surgery patients was associated with worsened 5-year clinical outcomes. (Safety and Efficacy Study of the Medtronic CoreValve System in the Treatment of Symptomatic Severe Aortic Stenosis in High Risk and Very High Risk Subjects Who Need Aortic Valve Replacement, NCT01240902; Safety and Efficacy Study of the Medtronic CoreValve System in the Treatment of Severe, Symptomatic Aortic Stenosis in Intermediate Risk Subjects Who Need Aortic Valve Replacement [SURTAVI], NCT01586910; Safety and Efficacy Continued Access Study of the Medtronic CoreValve System in the Treatment of Symptomatic Severe Aortic Stenosis in Very High Risk Subjects and High Risk Subjects Who Need Aortic Valve Replacement, NCT01531374).

Aortic Valve Replacement in the Current Era

Aortic valve disease (AVD) is a highly prevalent condition worldwide. Aortic valve replacement (AVR) is the surgical treatment for those with severe disease. Common etiologies of AVD include aortic stenosis (AS), aortic insufficiency (AI), endocarditis, and congenital diseases. Shared decision-making plays a large role in the treatment methodology chosen for each patient. Selection of valve type and surgical intervention requires strong considerations of age and compatibility with vitamin K antagonists (VKAs) to ensure optimal post-operative outcomes. Due to the development of novel surgical techniques, including transcatheter AVR (TAVR) and placement of sutureless valves, patients who previously had limited access to AVD surgical options can now be considered for AVR. Further research into therapeutic development is imperative to improve patient short- and long-term outcomes as well as widen surgical candidacy for those seeking AVR for the management of AVD. Overall, AVR will continue to hold its prominent role in the treatment of AVD.

Cost-effectiveness of TAVI in the United Kingdom: a long-term analysis based on 4-year data from the Evolut Low Risk Trial

BACKGROUND

The cost-effectiveness of transcatheter aortic valve implantation (TAVI) vs. surgical aortic valve replacement (SAVR) has previously been reported across the spectrum of surgical mortality risk. We present an updated analysis specific to the UK based on 4-year data from the Evolut Low Risk Trial, which showed a maintained numerical survival benefit with TAVI.

METHODS

A decision-analytic Markov model was used to project outcomes and costs over a lifetime horizon. Adverse events and utilities were modeled based on 4-year trial data. Beyond 4 years, no difference in long-term survival between TAVR and SAVR was assumed. Costs were informed by NHS England reference costs and reflect resource utilization in the UK TAVI Trial, with costs and effects discounted at 3.5% p.a. The lifetime incremental cost-effectiveness ratio (ICER) was evaluated against the established £20,000-£ 30,000 per QALY cost-effectiveness threshold. Extensive sensitivity and scenario analyses were performed, including comparison to prior results based on 12-month data.

RESULTS

TAVI improved survival by 0.41 life years and added 0.28 QALYs at incremental cost of £5,021, resulting in a lifetime ICER of £17,883 per QALY gained. 57.5% and 85.3% of probabilistic sensitivity analysis simulations were cost-effective at the £20,000 and £30,000 per QALY thresholds. Use of 4- vs. 1-year trial data markedly improved lifetime cost-effectiveness.

CONCLUSION

Recent 4-year follow-up data from the Evolut Low Risk trial suggest TAVI adds meaningful patient benefit over lifetime and can be expected to be a cost-effective intervention compared to SAVR for low surgical risk patients in a UK setting.

Timing of Aortic Valve Intervention in the Management of Aortic Stenosis

Aortic stenosis (AS) affects about 12% of people aged ≥75 years. Accumulating evidence on the prognostic importance of cardiac damage in patients with asymptomatic and less than severe AS supports the proposition of advancing aortic valve replacement (AVR) to earlier disease stages. Potential benefits of earlier treatment, including prevention of cardiac damage progression and reduced cardiovascular hospitalizations, need to be balanced against the earlier procedural risk and subsequent lifetime management after AVR. Two small, randomized trials indicate that early surgical AVR may improve survival in patients with asymptomatic severe AS, and observational data suggest that AVR may reduce mortality even in patients with moderate AS. A clear understanding of the pathophysiology of cardiac damage secondary to AS is needed to develop strategies to select patients for earlier AVR. Noninvasive imaging can detect early cardiac damage, and indices such as fibrosis, global longitudinal strain, and myocardial work index have potential use to guide stratification of patients for earlier AVR. Ongoing randomized trials are investigating the safety and efficacy of AVR for patients with asymptomatic severe AS and those with moderate AS who have symptoms/evidence of cardiac damage. Pathophysiological considerations and accumulating evidence from clinical studies that support earlier timing of AVR for AS will need to be corroborated by the results of these trials. This review aims to evaluate the evidence for earlier AVR, discuss strategies to guide stratification of patients who may benefit from this approach, highlight the relevant ongoing randomized trials, and consider the consequences of earlier intervention.