A device for attaching a heart pump in an opening of a ventricular wall of a beating heart, comprising - a hollow main body of general cylindrical shape having an outer surface, - this hollow main body comprising a proximal end and a distal end between which said outer surface extends, said distal end being intended to form a protrusion of said ventricular wall inside the corresponding ventricular cavity of the beating heart, - at least one portion of the outer surface of said main body intended to be placed inside said ventricular cavity, excluding the distal end thereof, has a surface relief provided with outgrowths and hollows made of a material enabling the adhesion and growth of endothelial cells, at least said outer surface portion comprising a coating covering a titanium or titanium alloy surface, - the distal end of said hollow main body forms a smooth crown having an arithmetic mean roughness R max which is less than or equal to 1 μm to stop the colonisation of said attachment device by endothelial cells, - said hollow main body includes a first hollow cylindrical body made entirely of titanium or titanium alloy, said first cylindrical body including said surface coating on at least one portion of the outer surface thereof, a second hollow cylindrical body having an outer flange at the end thereof, said second cylindrical body being inserted into said first hollow cylindrical body such that the end thereof is placed in the extension of said outer surface of the first cylindrical body forming a surface continuity therewith, said end of the second cylindrical body defining the distal end of said main body, the attachment device being characterised in that the second body is made of PEEK and has a smooth surface having an arithmetic mean roughness Rmax which is less than or equal to 1 μm. - a hollow main body of general cylindrical shape having an outer surface, - this hollow main body comprising a proximal end and a distal end between which said outer surface extends, said distal end being intended to form a protrusion of said ventricular wall inside the corresponding ventricular cavity of the beating heart, - at least one portion of the outer surface of said main body intended to be placed inside said ventricular cavity, excluding the distal end thereof, has a surface relief provided with outgrowths and hollows made of a material enabling the adhesion and growth of endothelial cells, at least said outer surface portion comprising a coating covering a titanium or titanium alloy surface, - the distal end of said hollow main body forms a smooth crown having an arithmetic mean roughness R max which is less than or equal to 1 μm to stop the colonisation of said attachment device by endothelial cells, - said hollow main body includes a first hollow cylindrical body made entirely of titanium or titanium alloy, said first cylindrical body including said surface coating on at least one portion of the outer surface thereof, a second hollow cylindrical body having an outer flange at the end thereof, said second cylindrical body being inserted into said first hollow cylindrical body such that the end thereof is placed in the extension of said outer surface of the first cylindrical body forming a surface continuity therewith, said end of the second cylindrical body defining the distal end of said main body, the attachment device being characterised in that the second body is made of PEEK and has a smooth surface having an arithmetic mean roughness Rmax which is less than or equal to 1 μm.