Table 1. Potential causes of prosthetic valve endocarditis.

1.	The non-sterile environment in the majority of cardiac catheterization laboratories.
2.	The high-risk profile of TAVI patients such as diabetes, immuno-suppression (i.e., steroids, myelodysplastic syndromes), and renal failure.
3.	Technical issues, as the frequent requirement to remove and re-implant a malpositioned THV (as leaflet and endothelial injury caused by manipulation) could increase the risk of PVE.
4.	Patient education, especially regarding the importance of post-implantation antibiotic prophylaxis.
5.	Adequate endothelialization of the bioprosthetic valve may require a dual antiplatelet therapy (aspirin and clopidogrel).
6.	Coincident infections.
7.	Low position of aortic THV being in direct contact with the mitral apparatus.
8.	Leaflet compression during transcatheter valve preparation and loading resulting in a degree of leaflet damage.
9.	Higher pre-procedural transaortic gradients in the PVE cases.
10.	Paravalvular leakage as it may be a possible ‘local’ risk factor for endocarditis.
11.	Male sex (2/3 of endocarditis patients) partially explained by the estrogen endothelial protection.
12.	Residual aortic regurgitation may induce endothelial damage (“jet lesions”) serving as a nidus during episodes of transient bacteremia.
13.	Bioprosthesis and the native aortic valve cusp space might be a suitable nidus for pathogen accumulation during transient bacteremia.
14.	Orotracheal intubation and the use of a self-expandable valve system were associated with IE post-TAVI
15.	TAVI in native valve
16.	Vascular complication

IE: infective endocarditis; PVE: prosthetic valve endocarditis; TAVI: transcatheter aortic valve implantation; THV: transcatheter heart valve.