Five-year outcomes in trials comparing transcatheter aortic valve implantation versus surgical aortic valve replacement: a pooled meta-analysis of reconstructed time-to-event data

Sutureless Aortic Prosthesis Valves versus Transcatheter Aortic Valve Implantation in Intermediate Risk Patients with Severe Aortic Stenosis: A Literature Review

Aortic stenosis remains the most frequently occurring valvular pathology in the elderly population of Western countries. According to the latest guidelines, the therapeutic choice of aortic stenosis depends on the age of the patient (<75 years or >75 years) and the risk class (STS-Prom/Euroscore II < o >4%). Therefore, if the surgical indication is clear in young and low-risk patients and percutaneous treatment is the gold standard in older and high-risk patients, the therapeutic choice is still debated in intermediate-risk patients. In this group of patients, aortic valve stenosis treatment depends on the patient's global evaluation, the experience of the center, and, no less importantly, the patient's will. Two main therapeutic options are debated: surgical aortic valve replacement with sutureless prosthesis versus transcatheter aortic valve implantation. In addition, the progressive development of mininvasive techniques for aortic valve surgery (right-anterior minithoracotomy) has also reduced the peri- and post-operative risk in this group of patients. The purpose of this review is to compare sutureless aortic valve replacement (SuAVR) versus TAVI in intermediate-risk patients with severe aortic stenosis.

An Updated Comprehensive Review of Existing Transcatheter Aortic Valve Replacement Access

For the past 20 years, transcatheter aortic valve replacement (TAVR) has been the treatment of choice for symptomatic aortic stenosis. The transfemoral (TF) access is considered the gold standard approach for TAVR. However, TF-TAVR cannot be performed in some patients; thus, alternative accesses are required. Our review paper generalises the TAVR accesses currently available, including the transapical, transaortic, trans-subclavian/axillary, transcarotid, transcaval, and suprasternal approaches. Their advantages and disadvantages have been analysed. Since there is no standard recommendation for an alternative approach, access selection depends on the expertise of the local cardiac team, patient characteristics, and access properties. Each TAVR centre is recommended to master a minimum of one non-TF access alternative. Of note, more evidence is required to delve into the clinical outcomes of each approach, at both early and long-term (Figure 1).

Comparative Outcomes of Surgical and Transcatheter Aortic Valve Replacement: A Meta-analysis and Parametric Extrapolation of Clinical Trials

INTRODUCTION

We aimed to pool randomized clinical trials (RCTs) comparing surgical aortic valve replacement (SAVR) with transcatheter aortic valve replacement (TAVR) and extrapolate pooled time-to-event data to compare long-term outcomes.

METHODS

An electronic database search was performed for RCTs comparing SAVR with TAVR. The most current longest follow-up data for each RCT were included. Data were pooled using a random-effects model. Survival data were pooled for Kaplan-Meier analysis as well as parametric modeling with extrapolation.

RESULTS

Seven RCTs comprising 7774 patients were included. Mean valve gradient at 5 y was comparable between SAVR [11 mmHg (3.7; 18.3)] and TAVR [8.1 mmHg (1.9; 14.3)] (P = 0.38). TAVR had a higher mean valve area at 30 d, 1 y, and 2 y [1.68 cm2 (1.22; 2.13) versus 1.8 cm2 (1.35; 2.25), P = 0.02]. SAVR had a higher freedom from any paravalvular leak at 30 d and 1 y [86% (81; 90) versus 39% (36; 41), P < 0.01]. All-cause death was lower in the SAVR group at 5 y [39% (29; 50) versus 43% (31; 57), P < 0.01]. Although no differences were seen between SAVR and TAVR in the pooled Kaplan-Meier analysis of all-cause mortality and composite of all-cause mortality or stroke, parametric modeling with extrapolation showed significant divergence for both outcomes.

CONCLUSIONS

Pooled all-cause mortality as well as pooled composite of all-cause mortality or stroke indicated better survival with SAVR at 5 y. Long-term parametric extrapolation also indicated superior survival with SAVR.

The evolution of TAVI performance overtime: an overview of systematic reviews

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is a well-established treatment for high and intermediate-risk patients with severe aortic stenosis (AS). Recent studies have demonstrated non-inferiority of TAVI compared to surgery in low-risk patients. In the past decade, numerous literature reviews (SLRs) have assessed the use of TAVI in different risk groups. This is the first attempt to provide an overview of SRs (OoSRs) focusing on secondary studies reporting clinical outcomes/process indicators. This research aims to summarize the findings of extant literature on the performance of TAVI over time.

METHODS

A literature search took place from inception to April 2024. We searched MEDLINE and the Cochrane Library for SLRs. SLRs reporting at least one review of clinical indicators were included. Subsequently, a two-step inclusion process was conducted: [1] screening based on title and abstracts and [2] screening based on full-text papers. Relevant data were extracted and the quality of the reviews was assessed.

RESULTS

We included 33 SLRs with different risks assessed via the Society of Thoracic Surgeons (STS) score. Mortality rates were comparable between TAVI and Surgical Aortic Valve Replacement (SAVR) groups. TAVI is associated with lower rates of major bleeding, acute kidney injury (AKI) incidence, and new-onset atrial fibrillation. Vascular complications, pacemaker implantation, and residual aortic regurgitation were more frequent in TAVI patients.

CONCLUSION

This study summarizes TAVI performance findings over a decade, revealing a shift to include both high and low-risk patients since 2020. Overall, TAVI continues to evolve, emphasizing improved outcomes, broader indications, and addressing challenges.

Surgical and transcatheter aortic valve replacement for severe aortic stenosis in low-risk elective patients: Analysis of the Aortic Valve Replacement in Elective Patients From the Aortic Valve Multicenter Registry

OBJECTIVES

Transcatheter aortic valve implantation (TAVI) remains the preferred strategy for high-risk or elderly individuals with aortic valve (AV) stenosis who are not considered to be optimal surgical candidates. Recent evidence suggests that low-risk patients may benefit from TAVI as well. The current study evaluates midterm survival in low-risk patients undergoing elective surgical AV replacement (SAVR) versus TAVI.

METHODS

The Aortic Valve Replacement in Elective Patients From the Aortic Valve Multicenter Registry (AVALON) compared isolated elective transfemoral TAVI or SAVR with sternotomy or minimally invasive approach in low-risk individuals performed between 2015 and 2019. Propensity score matching was conducted to determine SAVR controls for TAVI group in a 1-to-3 ratio with 0.2 caliper.

RESULTS

A total of 2393 patients undergoing elective surgery (1765 SAVR and 629 TAVI) with median European System for Cardiac Operative Risk Evaluation II (EuroSCORE II) score 1.81 (interquartile range [IQR], 1.36 to 2.53]) were initially included. Median follow-up was 2.72 years (IQR, 1.32-4.08; max 6.0). Propensity score matching returned 329 TAVI cases and 593 SAVR controls. Thirty-day mortality was 11 out of 329 (3.32%) in TAVI and 18 out of 593 (3.03%) in SAVR (risk ratio, 1.10; 95% CI, 0.52-2.37; P = .801) groups, respectively. At 2 years, survival curves began to diverge in favor of SAVR, which was associated with 30% lower mortality (hazard ratio, 0.70; 95% CI, 0.496-0.997; P = .048).

CONCLUSIONS

Our data did not demonstrate a survival difference between TAVI and SAVR during the first 2 postprocedure years. After that time, SAVR is associated with improved survival. Extended observations from randomized trials in low-risk patients undergoing elective surgery are warranted to confirm these findings and draw definitive conclusions.

Midterm Survival of Low-Risk Patients Treated With Transcatheter Versus Surgical Aortic Valve Replacement: Meta-Analysis of Reconstructed Time-to-Event Data

Background We performed a meta-analysis of reconstructed time-to-event data from randomized controlled trials (RCTs) and propensity-score matched (PSM) studies comparing transcatheter versus surgical aortic valve replacement (TAVR versus SAVR) to evaluate midterm outcomes in patients considered low risk for SAVR. Methods and Results Study-level meta-analysis of reconstructed time-to-event data from Kaplan-Meier curves of RCTs and PSM studies published by December 31, 2022 was conducted. Eight studies (3 RCTs, 5 PSM studies) met our eligibility criteria and included 5444 patients; 2639 patients underwent TAVR, and 2805 patients underwent SAVR. TAVR showed a higher risk of all-cause mortality at 8 years of follow-up (hazard ratio [HR] 1.22, [95% CI, 1.03-1.43], P=0.018). Up to 2 years of follow-up, TAVR was not inferior to SAVR (HR, 1.08 [95% CI, 0.89-1.31], P=0.448); however, we observed a statistically significant difference after 2 years with higher mortality with TAVR (HR, 1.51 [95% CI, 1.14-2.00]; P=0.004). This difference was driven by PSM studies; our sensitivity analysis showed a statistically significant difference between TAVR and SAVR when we included only PSM studies (HR, 1.41 [95% CI, 1.16-1.72], P=0.001) but no statistically significant difference when we included only RCTs (HR, 0.89 [95% CI, 0.69-1.16], P=0.398). Conclusions In comparison with TAVR, SAVR appeared to be associated with improved survival beyond 2 years in low-risk patients. However, the survival benefit of SAVR was observed only in PSM studies and not in RCTs. The addition of data from ongoing RCTs as well as longer follow-up in previous RCTs will help to confirm if there is a difference in mid- and long-term survival between TAVR versus SAVR in the low-risk population.

Bayesian interpretation of non-inferiority in transcatheter versus surgical aortic valve replacement trials: a systematic review and meta-analysis

OBJECTIVES

The concept of non-inferiority is widely adopted in randomized trials comparing transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR). However, uncertainty exists regarding the long-term outcomes of TAVR, and non-inferiority may be difficult to assess. We performed a systematic review and meta-analysis of randomized trials comparing TAVR and SAVR, with a specific emphasis on the non-inferiority margin for 5-year all-cause mortality.

METHODS

A systematic search was applied to 3 electronic databases. Randomized trials comparing TAVR and SAVR were included. Bayesian methods were implemented to evaluate the posterior probability of non-inferiority at different trial non-inferiority margins under either a vague, Cauchy, or a literature-based prior. Primary outcomes were 5-year actuarial all-cause mortality, and the probability of non-inferiority at various transformed trial non-inferiority margins. Secondary outcomes were long-term survival and 1- and 2-year actuarial survival.

RESULTS

Eight trials (n = 8698 patients) were included. Kaplan-Meier-derived 5-year survival was 61.6% (95% CI 59.8-63.5%) for TAVR, and 63.7% (95% CI 61.9-65.6%) for SAVR. Six trials (n = 6370 patients) reported all-cause mortality at 5-year follow-up. Under a vague prior, the posterior median relative risk for all-cause mortality of TAVR was 1.14, compared to SAVR (95% credible interval 1.06-1.22, probability of relative risk <1.00 = 0.01%, I2 = 0%). Similar results in terms of point estimate and uncertainty measures were obtained using frequentist methods. Based on the various trial non-inferiority margins, the results of the analysis suggest that non-inferiority at 5 years is no longer likely.

CONCLUSIONS

It is unlikely that TAVR is still non-inferior to SAVR at 5 years in terms of all-cause mortality.

Minimally Invasive Isolated Aortic Valve Replacement in a Potential TAVI Cohort of Patients Aged ≥ 75 Years: A Propensity-Matched Analysis

(1) Background and Objectives: Transcatheter aortic valve implantation is guideline-recommended from the age of 75. However, this European guideline recommendation is based on limited evidence, since no interaction between age and primary outcome has been found in guideline-stated references. This study aimed to compare the short-term outcomes of minimally invasive isolated aortic valve replacement in patients aged ≥ 75 with those of younger patients; (2) Patients and Methods: This retrospective cohort study included 1339 patients who underwent minimally invasive isolated aortic valve replacement at our facility between 2014 and 2022. This cohort was divided into two age-based groups: <75 and ≥75 years. Operative morbidity and mortality were compared between groups. Further analysis was performed using propensity score matching; (3) Results: After matching, 347 pairs of patients were included and analyzed. Despite the higher EuroSCORE II in the ≥75 group (2.2 ± 1.3% vs. 1.80 ± 1.34%, p ≤ 0.001), the 30-day mortality (1.4% vs. 1.2%; p = 0.90) and major adverse cardiac and cerebrovascular events, such as perioperative myocardial infarction (0.0% vs. 1.2%, p = 0.12) and stroke (1.4% vs. 2.6%, p = 0.06), were comparable between both treatment groups; (4) Conclusions: Minimally invasive aortic valve replacement is a safe treatment method for patients aged ≥ 75. Our results indicate that the unilateral cut-off of 75 years is not a limiting factor for performing minimally invasive aortic valve replacement.

Redo Surgical Aortic Valve Replacement versus Valve-In-Valve Transcatheter Aortic Valve Implantation: A Systematic Review and Reconstructed Time-To-Event Meta-Analysis

Objective. Valve-in-valve transcatheter aortic valve implantation (ViV-TAVI) has emerged as a useful alternative intervention to redo-surgical aortic valve replacement (Redo-SVAR) for the treatment of degenerated bioprosthesis valve. However, there is no robust evidence about the long-term outcome of both treatments. The aim of this meta-analysis was to analyze the long-term outcomes of Redo-SVAR versus ViV-TAVI by reconstructing the time-to-event data. Methods. The search strategy consisted of a comprehensive review of relevant studies published between 1 January 2000 and 30 September 2022 in three electronic databases, PubMed, Cochrane Central Register of Controlled Trials (CENTRAL) and EMBASE. Relevant studies were retrieved for the analysis. The primary endpoint was the long-term mortality for all death. The comparisons were made by the Cox regression model and by landmark analysis and a fully parametric model. A random-effect method was applied to perform the meta-analysis. Results. Twelve studies fulfilled the eligibility criteria and were included in the final analysis. A total of 3547 patients were included. Redo-SAVR group included 1783 patients, and ViV-TAVI included 1764 subjects. Redo-SAVR showed a higher incidence of all-cause mortality within 30-days [Hazard ratio (HR) 2.12; 95% CI = 1.49−3.03; p < 0.0001)], whereas no difference was observed between 30 days and 1 year (HR = 1.03; 95% CI = 0.78−1.33; p = 0.92). From one year, Redo-SAVR showed a longer benefit (HR = 0.52; 95% CI = 0.40−0.67; p < 0.0001). These results were confirmed for cardiovascular death (HR = 2.04; 95% CI = 1.29−3.22; p = 0.001 within one month from intervention; HR = 0.35; 95% CI = 0.18−0.71; p = 0.003 at 4-years follow-up). Conclusions. Although the long-term outcomes seem similar between Redo-SAVR and ViV-TAVI at a five-year follow-up, ViV-TAVI shows significative lower mortality within 30 days. This advantage disappeared between 30 days and 1 year and reversed in favor of redo-SAVR 1 year after the intervention.

Risk of Bias in Randomized Clinical Trials Comparing Transcatheter and Surgical Aortic Valve Replacement: A Systematic Review and Meta-analysis

IMPORTANCE

Recent European Society of Cardiology/European Association for Cardio-Thoracic Surgery (ESC/EACTS) guidelines highlighted some concerns about the randomized clinical trials (RCTs) comparing transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) for aortic stenosis. Quantification of these biases has not been previously performed.

OBJECTIVE

To assess whether randomization protects RCTs comparing TAVI and SAVR from biases other than nonrandom allocation.

DATA SOURCES

A systematic review of the literature between January 1, 2007, and June 6, 2022, on MEDLINE, Embase, and Cochrane Central Register of Controlled Trials was performed. Specialist websites were also checked for unpublished data.

STUDY SELECTION

The study included RCTs with random allocation to TAVI or SAVR with a maximum 5-year follow-up.

DATA EXTRACTION AND SYNTHESIS

Data extraction was performed by 2 independent investigators following the PRISMA guidelines. A random-effects meta-analysis was used for quantifying pooled rates and differential rates between treatments of deviation from random assigned treatment (DAT), loss to follow-up, and receipt of additional treatments.

MAIN OUTCOMES AND MEASURES

The primary outcomes were the proportion of DAT, loss to follow-up, and patients who were provided additional treatments and myocardial revascularization, together with their ratio between treatments. The measures were the pooled overall proportion of the primary outcomes and the risk ratio (RR) in the TAVI vs SAVR groups.

RESULTS

The search identified 8 eligible trials including 8849 participants randomly assigned to undergo TAVI (n = 4458) or SAVR (n = 4391). The pooled proportion of DAT among the sample was 4.2% (95% CI, 3.0%-5.6%), favoring TAVI (pooled RR vs SAVR, 0.16; 95% CI, 0.08-0.36; P < .001). The pooled proportion of loss to follow-up was 4.8% (95% CI, 2.7%-7.3%). Meta-regression showed a significant association between the proportion of participants lost to follow-up and follow-up time (slope, 0.042; 95% CI, 0.017-0.066; P < .001). There was an imbalance of loss to follow-up favoring TAVI (RR, 0.39; 95% CI, 0.28-0.55; P < .001). The pooled proportion of patients who had additional procedures was 10.4% (95% CI, 4.4%-18.5%): 4.6% (95% CI, 1.5%-9.3%) in the TAVI group and 16.5% (95% CI, 7.5%-28.1%) in the SAVR group (RR, 0.27; 95% CI, 0.15-0.50; P < .001). The imbalance between groups also favored TAVI for additional myocardial revascularization (RR, 0.40; 95% CI, 0.24-0.68; P < .001).

CONCLUSIONS AND RELEVANCE

This study suggests that, in RCTs comparing TAVI vs SAVR, there are substantial proportions of DAT, loss to follow-up, and additional procedures together with systematic selective imbalance in the same direction characterized by significantly lower proportions of patients undergoing TAVI that might affect internal validity.

Immediate and late outcomes of transcatheter aortic valve implantation versus surgical aortic valve replacement in bicuspid valves: Meta-analysis of reconstructed time-to-event data

BACKGROUND

Outcomes of transcatheter aortic valve implantation (TAVI) versus surgical aortic valve replacement (SAVR) in patients with aortic stenosis and bicuspid aortic valve (BAV) must be better investigated.

METHODS

A meta-analysis including studies published by January 2022 reporting immediate outcomes (in-hospital death, stroke, acute kidney injury [AKI], major bleeding, new permanent pacemaker implantation [PPI], paravalvular leakage [PVL]), mortality in the follow-up (with Kaplan-Meier curves for reconstruction of individual patient data).

RESULTS

Five studies met our eligibility criteria. No statistically significant difference was observed for in-hospital death, stroke, AKI, and PVL. TAVI was associated with lower risk of major bleeding (odds ratio [OR]: 0.29; 95% confidence interval [CI]: 0.12-0.69; p = .025), but higher risk of PPI (OR: 2.00; 95% CI: 1.05-3.77; p = .041). In the follow-up, mortality after TAVI was significantly higher in the analysis with the largest samples (HR: 1.24, 95% CI: 1.01-1.53, p = .043), but no statistically significant difference was observed with risk-adjusted populations (HR: 1.06, 95% CI: 0.86-1.32, p = .57). Landmark analyses suggested a time-varying risk with TAVI after 10 and 13 months in both largest and risk-adjusted populations (HR: 2.13, 95% CI: 1.45-3.12, p < .001; HR: 1.7, 95% CI: 1.11-2.61, p = .015, respectively).

CONCLUSION

Considering the immediate outcomes and comparable overall survival observed in risk-adjusted populations, TAVI can be used safely in selected BAV patients. However, a time-varying risk is present (favoring SAVR over TAVI at a later timepoint). This finding was likely driven by higher rates of PPI with TAVI.