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Risk of Bias in Randomized Clinical Trials Comparing Transcatheter and Surgical Aortic Valve Replacement: A
Fabio Barili1,2, James M Brophy3, Daniele Ronco4
1Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, Massachusetts.
JAMA Network Open
|January 3, 2023
Summary
Randomized trials comparing transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) show significant deviations from assigned treatment and loss to follow-up. These imbalances, particularly favoring TAVI, may impact the internal validity of TAVI vs. SAVR studies.
Area of Science:
- Cardiovascular Medicine
- Interventional Cardiology
- Clinical Trial Methodology
Background:
- European Society of Cardiology/European Association for Cardio-Thoracic Surgery (ESC/EACTS) guidelines raised concerns regarding biases in randomized clinical trials (RCTs) comparing transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR).
- Quantification of these potential biases in TAVI vs. SAVR RCTs has not been previously performed.
Approach:
- A systematic review and meta-analysis of RCTs comparing TAVI and SAVR published between 2007 and 2022 was conducted.
- Data extraction focused on deviation from assigned treatment (DAT), loss to follow-up, and receipt of additional treatments, with a random-effects meta-analysis used for quantification.
Key Points:
- Eight RCTs involving 8849 participants were analyzed.
- A pooled proportion of 4.2% deviation from assigned treatment (DAT) was observed, favoring TAVI (RR, 0.16).
- Loss to follow-up was 4.8%, also favoring TAVI (RR, 0.39), and increased with follow-up duration.
- Additional procedures were performed in 10.4% of patients, significantly less in the TAVI group (4.6%) compared to SAVR (16.5%).
Conclusions:
- Randomized clinical trials comparing TAVI and SAVR exhibit substantial deviations from assigned treatment, loss to follow-up, and additional procedures.
- Systematic imbalances favoring TAVI were noted across these outcomes, potentially affecting the internal validity of these comparative studies.
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