A systematic review of the evidence supporting the use of surgical aortic and mitral valves: an update from the CORE MD consortium
Authors: Mcgovern L , Coughlan J J , Siontis G , Frenk A , Melvin T , Mcgauran G , Geertsma R , Schnell-Inderst P , Fraser A G , Windecker S , Byrne R A 
Published: November 2023

Abstract

Introduction
The European Union (EU) Medical Device Regulation (MDR) 2017/745 challenges the medical community to engage with regulators, notified bodies and industry to develop transparent, rigorous and proportionate methods to evaluate the clinical safety and efficacy of medical devices and to monitor their performance. As part of the EU Horizon 2020 funded CORE-MD project, we performed a systematic review of the published scientific evidence available for surgical heart valve replacements for native aortic and mitral valve pathologies.

Purpose
The aim of this analysis is to review the scientific evidence available which supports the use of currently available surgical aortic and mitral valves.

Methods
A systematic literature review was conducted using Ovid, MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL). We included only surgical aortic and mitral valves that received CE Mark approval from the year 2000 onwards. We included any study of prospective design (randomised or non-randomised clinical trials of any design) in humans, published between 2000 and 2021. We excluded retrospective studies, case reports, reviews, systematic reviews, meta-analyses, and expert opinion documents. Title and abstract screening, full-text review, risk of bias evaluation and data collection were performed by two authors independently, with disagreements resolved by discussion with a third author.

Results
A total of 17 surgical aortic valves and 4 surgical mitral valves were identified based on the CE mark criterion (Figure 1). The initial literature search identified 4901 and 3696 potentially eligible papers in the aortic and mitral valve categories, respectively. Finally, 39 aortic and 3 mitral valve studies were included (Figure 2). The majority of included studies (90%) had a non-randomised, prospective, observational design, with 68% receiving industry funding. The median number of patients included was 295 [interquartile range (IQR): 153, 689] with a median maximum follow up of 24 months [IQR: 12, 60]. Only 50% of the identified studies had a pre-specified registered study protocol and only 5% included a power calculation to estimate the required study size. No study reported patient involvement in the study design and only 15% of studies had a comparator group. Using the ROBINS I AND II assessment tools, 90% of the included studies were classified as having a high or serious risk of bias.

Conclusion
The evidence available for currently used surgical aortic and mitral replacement heart valves is largely from small, industry funded, non-randomised controlled trials. The median duration of maximum follow up was only 24 months, the majority of studies were classed as having a high/serious risk of bias and only half had a pre-registered study protocol. These results highlight the limitations of the available scientific evidence supporting the surgical aortic and mitral valves used in current clinical practice.Surgical aortic and mitral valvesSummary of literature search results