Appendix 1. OVID MEDLINE Search Strategy

1. exp leukocytes/

2. Leukocyte Reduction Procedures/

3. Filtration/

4. leu?odeplet*.tw.

5. leu?ocyt*.tw.

6. white blood cell*.tw.

7. wbc.tw.

8. neutrophil*.tw.

9. or/1‐8

10. exp Heart Valve Diseases/

11. Heart Valve Prosthesis/

12. Heart Valve Prosthesis Implantation/

13. ((heart or cardiac or aortic or mitral or pulmonary or tricuspid) adj3 valv*).tw.

14. ((heart or cardiac or aortic or mitral or pulmonary or tricuspid or valv*) adj3 (prosthes?s or incompetenc* or regurgitation* or insufficienc* or stenos?s)).tw.

15. ((heart or cardiac or aortic or mitral or pulmonary or tricuspid or valv*) adj4 (surg* or replace* or repair* or reconstruc* or operat*)).tw.

16. or/10‐15

17. 9 and 16

18. randomized controlled trial.pt.

19. controlled clinical trial.pt.

20. randomized.ab.

21. placebo.ab.

22. drug therapy.fs.

23. randomly.ab.

24. trial.ab.

25. groups.ab.

26. 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25

27. exp animals/ not humans.sh.

28. 26 not 27

29. 17 and 28