Meta-Analysis of Transcatheter Aortic Valve Replacement in Low-Risk Patients

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.

Time trends in the epidemiology of nonrheumatic aortic valve disease in Spain, 2003-2018

INTRODUCTION AND OBJECTIVES

The impact of therapeutic improvements in nonrheumatic aortic valve disease (NRAVD) has been assessed at the patient level but not in the whole population with the disease. Our objective was to assess temporal trends in hospitalization rates, treatment and fatality rates in patients with a main or secondary NRAVD diagnosis.

METHODS

Retrospective analysis of administrative claims from patients hospitalized with a main or secondary NRAVD diagnosis between 2003 and 2018 in Spain. Time trends in age- and sex-standardized hospitalization and procedure rates, baseline characteristics and case fatality rates by diagnosis type were assessed by Poisson regression and joinpoint analysis.

RESULTS

Hospital admissions in patients with NRAVD increased from 69 213 in 2003 to 136 185 in 2018. The crude in-hospital fatality rate increased from 6.7% to 8.7% (IRR, 1.015; 95%CI, 1.012-1.018; P <.001) without changes after adjustment. Adjusted fatality rates decreased in patients with a main NRAVD diagnosis (5.5% to 3.5%; IRR, 0.953; 95%CI, 0.942-0.964) but increased in those with a secondary diagnosis (8.0% to 8.8%; IRR, 1.005; 95%CI, 1.002-1.009). Aortic valve replacements increased from 10.5 to 17.1 procedures per 100 000 population (IRR, 1.033; 95%CI, 1.030-1.037), mainly driven by transcatheter procedures (IRR, 1.345; 95%CI, 1.302-1.389).

CONCLUSIONS

Hospitalizations in patients with NRAVD are increasing, with most being secondary diagnoses. The use of aortic valve replacement is increasing with a reduction in fatality rates but only in patients with a main diagnosis.

Impact of new-onset versus pre-existing atrial fibrillation on outcomes after transcatheter aortic valve replacement/implantation

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Atrial fibrillation increases the risk of all primary and secondary outcomes after TAVR/TAVI.

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NOAF is associated with a higher risk of 30-day mortality, stroke, and extended LOS after TAVR/TAVI.

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Pre-AF is associated with a higher risk of AKI and early bleeding episodes after TAVR/TAVI.

Patients with aortic stenosis who undergo transcatheter aortic valve replacement/transcatheter aortic valve implantation (TAVR/TAVI) experience a high incidence of pre-existing atrial fibrillation (pre-AF) and new-onset atrial fibrillation (NOAF) post-operatively. This systematic review and meta-analysis aimed to update current evidence concerning the incidence of 30-day mortality, stroke, acute kidney injury (AKI), length of stay (LOS), and early/late bleeding in patients with NOAF or pre-AF who undergo TAVR/TAVI. PubMed, Google Scholar, JSTOR, Cochrane Library, and Web of Science were searched for studies published between January 2012 and December 2020 reporting the association between NOAF/pre-AF and clinical complications after TAVR/TAVI. A total of 15 studies including 158,220 adult patients with TAVI/TAVR and NOAF or pre-AF were identified. Compared to patients in sinus rhythm, patients who developed NOAF had a higher risk of 30-day mortality, AKI, early bleeding events, extended LOS, and stroke after TAVR/TAVI (odds ratio [OR]: 3.18 [95% confidence interval [CI] 1.58, 6.40]) (OR: 3.83 [95% CI 1.18, 12.42]) (OR: 1.70 [95% CI 1.05, 2.74]) (OR: 13.96 [95% CI, 6.41, 30.40]) (OR: 2.51 [95% CI 1.59, 3.97], respectively). Compared to patients in sinus rhythm, patients with pre-AF had a higher risk of AKI and early bleeding episodes after TAVR/TAVI (OR: 2.43 [95% CI 1.10, 5.35]) (OR: 17.41 [95% CI 6.49, 46.68], respectively). Atrial fibrillation is associated with a higher risk of all primary and secondary outcomes. Specifically, NOAF but not pre-AF is associated with a higher risk of 30-day mortality, stroke, and extended LOS after TAVR/TAVI.

Application research of three-dimensional transesophageal echocardiography in predicting prosthetic valve size for transcatheter aortic valve implantation

Background

Transcatheter aortic valve implantation (TAVI) is an alternative method to treat patients with severe aortic valve disease. Accurate measurement of the aortic valve annulus and selection of the appropriate artificial valve are critical to the success of TAVI. Multilayer spiral computed tomography (MSCT) is recommended as the “gold standard” for assessing the aortic valve annulus before TAVI. However, MSCT scanning may not be possible for patients with iodine allergy, renal failure, or pregnancy. The purpose of this study is to evaluate the aortic valve annulus by three-dimensional transesophageal echocardiography (3D-TEE) and compare the results with MSCT, exploring the feasibility of 3D-TEE to guide the selection of artificial valve implantation in TAVI.

Methods

We retrospectively analyzed 74 patients who successfully underwent TAVI in our hospital. Before the operation, 3D-TEE and MSCT were used to measure the maximum diameter, minimum diameter, area-derived diameter, and perimeter-derived diameter of the aortic valve annulus, and the results were analyzed for consistency. To predict the valve size based on 3D-TEE and the MSCT area-derived diameter, we compared the differences between the predicted valve size and the actual implanted valve size, and analyzed the differences between 3D-TEE and MSCT for guiding the selection of the prosthetic valve size.

Results

There was no significant difference between 3D-TEE and MSCT in the measurement of the maximum diameter, minimum diameter, area, and perimeter of the aortic annulus and their derived diameter (P>0.05). The intraclass correlation coefficients for the maximum diameter, minimum diameter, area-derived diameter, and perimeter-derived diameter of the aortic annulus were 0.89, 0.83, 0.84, and 0.92, respectively. There was no statistical difference in the accuracy of both methods, 3D-TEE and MSCT, in predicting different prosthetic valve sizes for TAVI (P>0.05).

Conclusions

3D-TEE and MSCT have good agreement for measuring the values of various parameters of the aortic annulus. The accuracy of both methods was similar for predicting the aortic prosthetic valve size. 3D-TEE may provide guidance for selecting the prosthetic valve size for TAVI.

Transcatheter aortic valve implantation versus surgical aortic valve replacement in patients with severe aortic stenosis: a systematic review and meta-analysis

OBJECTIVES

Patients undergoing surgery for severe aortic stenosis (SAS) can be treated with either transcatheter aortic valve implantation (TAVI) or surgical aortic valve replacement (SAVR). The choice of procedure depends on several factors, including the clinical judgement of the heart team and patient preferences, which are captured by actively informing and involving patients in a process of shared decision making (SDM). We synthesised the most up-to-date and accessible evidence on the benefits and risks that may be associated with TAVI versus SAVR to support SDM in this highly personalised decision-making process.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE (Ovid), Embase (Ovid) and the Cochrane Central Register of Controlled Trials (CENTRAL; Wiley) were searched from January 2000 to August 2020 with no language restrictions. Reference lists of included studies were searched to identify additional studies.

ELIGIBILITY CRITERIA

Randomised controlled trials (RCTs) that compared TAVI versus SAVR in patients with SAS and reported on all-cause or cardiovascular mortality, length of stay in intensive care unit or hospital, valve durability, rehospitalisation/reintervention, stroke (any stroke or major/disabling stroke), myocardial infarction, major vascular complications, major bleeding, permanent pacemaker (PPM) implantation, new-onset or worsening atrial fibrillation (NOW-AF), endocarditis, acute kidney injury (AKI), recovery time or pain were included.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers were involved in data extraction and risk of bias (ROB) assessment using the Cochrane tool (one reviewer extracted/assessed the data, and the second reviewer checked it). Dichotomous data were pooled using the Mantel-Haenszel method with random-effects to generate a risk ratio (RR) with 95% CI. Continuous data were pooled using the inverse-variance method with random-effects and expressed as a mean difference (MD) with 95% CI. Heterogeneity was assessed using the I² statistic.

RESULTS

8969 records were retrieved and nine RCTs (61 records) were ultimately included (n=8818 participants). Two RCTs recruited high-risk patients, two RCTs recruited intermediate-risk patients, two RCTs recruited low-risk patients, one RCT recruited high-risk (≥70 years) or any-risk (≥80 years) patients; and two RCTs recruited all-risk or 'operable' patients. While there was no overall change in the risk of dying from any cause (30 day: RR 0.89, 95% CI 0.65 to 1.22; ≤1 year: RR 0.90, 95% CI 0.79 to 1.03; 5 years: RR 1.09, 95% CI 0.98 to 1.22), cardiovascular mortality (30 day: RR 1.03, 95% CI 0.77 to 1.39; ≤1 year: RR 0.90, 95% CI 0.76 to 1.06; 2 years: RR 0.96, 95% CI 0.83 to 1.12), or any type of stroke (30 day: RR 0.83, 95% CI 0.61 to 1.14;≤1 year: RR 0.94, 95% CI 0.72 to 1.23; 5 years: RR 1.07, 95% CI 0.88 to 1.30), the risk of several clinical outcomes was significantly decreased (major bleeding, AKI, NOW-AF) or significantly increased (major vascular complications, PPM implantation) for TAVI vs SAVR. TAVI was associated with a significantly shorter hospital stay vs SAVR (MD -3.08 days, 95% CI -4.86 to -1.29; 4 RCTs, n=2758 participants). Subgroup analysis generally favoured TAVI patients receiving implantation via the transfemoral (TF) route (vs non-TF); receiving a balloon-expandable (vs self-expanding) valve; and those at low-intermediate risk (vs high risk). All RCTs were rated at high ROB, predominantly due to lack of blinding and selective reporting.

CONCLUSIONS

No overall change in the risk of death from any cause or cardiovascular mortality was identified but 95% CIs were often wide, indicating uncertainty. TAVI may reduce the risk of certain side effects while SAVR may reduce the risk of others. Most long-term (5-year) results are limited to older patients at high surgical risk (ie, early trials), therefore more data are required for low risk populations. Ultimately, neither surgical technique was considered dominant, and these results suggest that every patient with SAS should be individually engaged in SDM to make evidence-based, personalised decisions around their care based on the various benefits and risks associated with each treatment.

PROSPERO REGISTRATION NUMBER

CRD42019138171.

Predictors of Early Stroke or Death in Patients Undergoing Transcatheter Aortic Valve Implantation

BACKGROUND/OBJECTIVE

While postoperative stroke is a known complication of Transcatheter Aortic Valve Implantation (TAVI), predictors of early stroke occurrence have not been specifically reviewed. The objective of this study was to estimate the predictors and incidence of stroke during the first 30 days post-TAVI.

METHODS

A cohort of 506 consecutive patients having undergone TAVI between January 2017 and June 2019 was extracted from a prospective database. Preoperative, intraoperative and postoperative characteristics were analyzed by univariate analysis followed by logistic regression to find predictors of the occurrence of stroke or death within the first 30 days after the procedure.

RESULTS

Incidence of stroke within 30 days post-TAVI was 4.9%, [CI 95% 3.3-7.2], i.e., 25 strokes. Four out of the 25 patients (16%) with a stroke died within 30 days post-TAVI. After logistic regression analysis, the predictors of early stroke related to TAVI were: CHA2Ds2VASc score ≥ 5 (odds ratio [OR] 2.62; 95% CI: 1.06-6.49; p = .037), supra-aortic access vs. femoral access (OR: 9.00, 95%CI: 2.95-27.44; p = .001) and introduction post-TAVI of a single vs. two or three antithrombotic agents (OR: 5.13; CI 95%: 1.99 to 13.19; p = .001). Over the 30-day period, bleeding occurred in 28 patients (5.5%), in 25 of whom, it was associated with femoral or iliac artery access injury. Anti-thrombotic regimen was not associated with bleeding; two patients out of 48 (4.1%) bled with a single anti-thrombotic regimen vs. 26 patients out of 458 (5.6%) with a dual or triple anti-thrombotic regimen (p = 0.94). The overall 30-day mortality rate was 3.9%, [95% CI 2.5-6.0]. Patients with a single post-TAVI antithrombotic agent (OR: 44.07 [CI 95% 13.45-144.39]; p < .0001) and patients with previous coronary artery bypass surgery or coronary artery stenting (OR: 6.16, [CI 95% 1.99-21.29]; p = .002) were at significantly higher risk of death within the 30-day period.

CONCLUSION

In this large-scale single-center retrospective study, a single post-TAVI antithrombotic regimen independently predicted occurrence of early stroke or death. Dual or triple antithrombotic regimen was not associated with a higher risk of bleeding and should be considered as an option in patients undergoing TAVI.

Transcatheter Versus Surgical Aortic Valve Replacement in Low-Risk Patients for the Treatment of Severe Aortic Stenosis

Recently, two randomized trials, the PARTNER 3 and the Evolut Low Risk Trial, independently demonstrated that transcatheter aortic valve replacement (TAVR) is non-inferior to surgical aortic valve replacement (SAVR) for the treatment of severe aortic stenosis in patients at low surgical risk, paving the way to a progressive extension of clinical indications to TAVR. We designed a meta-analysis to compare TAVR versus SAVR in patients with severe aortic stenosis at low surgical risk. The study protocol was registered in PROSPERO (CRD42019131125). Randomized studies comparing one-year outcomes of TAVR or SAVR were searched for within Medline, Scholar and Scopus electronic databases. A total of three randomized studies were selected, including nearly 3000 patients. After one year, the risk of cardiovascular death was significantly lower with TAVR compared to SAVR (Risk Ratio (RR) = 0.56; 95% CI 0.33–0.95; p = 0.03). Conversely, no differences were observed between the groups for one-year all-cause mortality (RR = 0.67; 95% CI 0.42–1.07; p = 0.10). Among the secondary endpoints, patients undergoing TAVR have lower risk of new-onset of atrial fibrillation compared to SAVR (RR = 0.26; 95% CI 0.17–0.39; p < 0.00001), major bleeding (RR = 0.30; 95% CI 0.14–0.65; p < 0.002) and acute kidney injury stage II or III (RR = 0.28; 95% CI 0.14–0.58; p = 0.0005). Conversely, TAVR was associated to a higher risk of aortic regurgitation (RR = 3.96; 95% CI 1.31–11.99; p = 0.01) and permanent pacemaker implantation (RR = 3.47; 95% CI 1.33–9.07; p = 0.01) compared to SAVR. No differences were observed between the groups in the risks of stroke (RR= 0.71; 95% CI 0.41–1.25; p = 0.24), transient ischemic attack (TIA; RR = 0.98; 95% CI 0.53–1.83; p = 0.96), and MI (RR = 0.75; 95% CI 0.43–1.29; p = 0.29). In conclusion, the present meta-analysis, including three randomized studies and nearly 3000 patients with severe aortic stenosis at low surgical risk, shows that TAVR is associated with lower CV death compared to SAVR at one-year follow-up. Nevertheless, paravalvular aortic regurgitation and pacemaker implantation still represent two weak spots that should be solved.