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    Interventional procedure overview of off-pump minimal access mitral valve repair by artificial chordae insertion to treat mitral regurgitation

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    Appendix A: Methods and literature search strategy

    NICE has identified studies and reviews relevant to beating heart mitral valve repair by artificial chordae insertion for mitral regurgitation from the medical literature.

    Search strategy design and peer review

    This search report is informed by the Preferred Reporting Items for Systematic reviews and Meta-Analyses literature search extension (PRISMA-S).

    A NICE information specialist ran the literature searches on 06 May 2025. See the search strategy history for the full search strategy for each database. Relevant published studies identified during consultation or resolution that are published after this date may also be considered for inclusion.

    The principal search strategy was developed in MEDLINE ALL (Ovid interface). It was adapted for use in each of the databases listed in table 4a, taking into account the database's size, search functionality and subject coverage. The MEDLINE ALL strategy was quality assured by a NICE senior information specialist. All translated search strategies were peer reviewed to ensure their accuracy. The quality assurance and peer review procedures were adapted from the Peer Review of Electronic Search Strategies (PRESS) 2015 evidence-based checklist.

    Review management

    The search results were managed in EPPI‑Reviewer version 5 (EPPI‑R5). Duplicates were removed in EPPI‑R5 using a 2‑step process. First, automated deduplication was done using a high-value algorithm. Second, manual deduplication was used to assess low-probability matches. All decisions about inclusion, exclusion and deduplication were recorded and stored.

    Limits and restrictions

    The CENTRAL database search removed trial registry records and conference material. The Embase search excluded conference material.

    English language limits were applied to the search when possible in the database.

    The limit to remove animal studies in the searches is standard NICE practice, which has been adapted from Dickersin K, Scherer R, Lefebvre C (1994) Systematic Reviews: Identifying relevant studies for systematic reviews. BMJ 309(6964): 1286.

    Search strategy history

    MEDLINE ALL search strategy

    1 mitral valve insufficiency/ 27504

    2 Mitral Valve Prolapse/ 5400

    3 (Mitral adj4 (prolapse* or disease* or regurgitat* or insufficien* or rupture* or incompetence or floppy or click-murmur)).tw. 34296

    4 or/1-3 46050

    5 (beating heart adj5 repair*).tw. 131

    6 (artificial adj4 (chord* or neo-chord*)).tw. 406

    7 (implant* adj4 (chord* or neo-chord*)).tw. 179

    8 or/5-7 603

    9 4 and 8 432

    10 NeoChord.tw. 132

    11 (HARPOON and (mitral or "beating heart" or "repair system")).tw. 16

    12 10 or 11 142

    13 9 or 12 527

    14 limit 13 to english language 484

    15 animals/ not humans/ 5307231

    16 14 not 15 447

    Embase search strategy

    1 mitral valve regurgitation/ 60107

    2 Mitral Valve Prolapse/ 10727

    3 (Mitral adj4 (prolapse* or disease* or regurgitat* or insufficien* or rupture* or incompetence or floppy or click-murmur)).tw. 52495

    4 or/1-3 79506

    5 (beating heart adj5 repair*).tw. 198

    6 (artificial adj4 (chord* or neo-chord*)).tw. 574

    7 (implant* adj4 (chord* or neo-chord*)).tw. 309

    8 or/5-7 894

    9 4 and 8 605

    10 NeoChord.tw. 249

    11 (HARPOON and (mitral or "beating heart" or "repair system")).tw. 23

    12 10 or 11 265

    13 9 or 12 775

    14 limit 13 to english language 735

    15 Nonhuman/ not Human/ 5683074

    16 14 not 15 684

    17 (conference abstract* or conference review or conference paper or conference proceeding).db,pt,su. 6252247

    18 16 not 17 413

    Cochrane Library (CDSR and CENTRAL) search strategy

    #1 MeSH descriptor: [Mitral Valve Insufficiency] explode all trees 605

    #2 MeSH descriptor: [Mitral Valve Prolapse] explode all trees 59

    #3 (Mitral near/4 (prolapse* or disease* or regurgitat* or insufficien* or rupture* or incompetence or floppy or click-murmur)) 1696

    #4 {or #1-#3} 1696

    #5 (beating heart near/5 repair*) 4

    #6 (artificial near/4 (chord* or neo-chord*)) 5

    #7 (implant* near/4 (chord* or neo-chord*)) 4

    #8 {or #5-#7} 10

    #9 #4 and #8 7

    #10 NeoChord 5

    #11 (HARPOON and (mitral or "beating heart" or "repair system")) 0

    #12 #10 or #11 5

    #13 #9 or #12 10

    #14 "conference":pt or (clinicaltrials or trialsearch):so 824537

    #15 #13 not #14 5

    INAHTA HTA Database search strategy

    #1. "Mitral Valve Insufficiency"[mh]

    #2. "Mitral Valve prolapse"[mh]

    #3. (Mitral and (prolapse* or disease* or regurgitat* or insufficien* or rupture* or incompetence or floppy or click-murmur))

    #4. #1 or #2 or #3

    #5. ((beating heart) and repair*)

    #6. (artificial AND (chord* or neo-chord*))

    #7. (implant* AND (chord* or neo-chord*))

    #8. #5 or #6 or #7

    #9. NeoChord

    #10. (HARPOON and (mitral or "beating heart" or "repair system"))

    #11. #9 or #10

    #12. #4 and #8

    #13. #11 or #12

    Inclusion criteria

    The following inclusion criteria were applied to the abstracts identified by the literature search.

    • Publication type: clinical studies were included with emphasis on identifying good quality studies. Abstracts were excluded if they did not report clinical outcomes. Reviews, editorials, and laboratory or animal studies, were also excluded and so were conference abstracts, because of the difficulty of appraising study methodology, unless they reported specific adverse events not available in the published literature.

    • People with mitral regurgitation

    • Intervention or test: NeoChord DS1000 System.

    • Outcome: articles were retrieved if the abstract contained information relevant to the safety, efficacy, or both.

    If selection criteria could not be determined from the abstracts the full paper was retrieved.

    Potentially relevant studies not included in the main evidence summary are listed in Appendix B: Other relevant studies.

    Find out more about how NICE selects the evidence for the committee.