High durability heart valve

Abstract

An improved heart bioprosthetic device having a metal frame wireform or stent having an outer external surface. The metal frame has a bond layer coating at least a portion of the external surface and a coating layer disposed on at least a portion of the bond layer. The bond layer comprises a metal selected from the group consisting of: chromium, titanium, zirconium, aluminum, platinum, palladium, and niobium. The coating layer is selected from the group consisting of: a metal nitride, a metal oxide, a metal carbide, and combinations thereof. The coating layer may have a thickness of about 10 μm or less and a grain size of about 10 nm to about 15 nm, and may be characterized as polycrystalline with randomly-oriented grains with both cubic and orthorhombic phases. In one embodiment, the bond layer comprises chromium and the coating layer comprises chromium nitride.

What is claimed is: 
     
         1 . A prosthetic heart valve comprising:
 a metal frame;   a bond layer disposed over at least a portion of the metal frame, the bond layer comprising at least one elemental metal;   a coating layer disposed over at least a portion of the bond layer, the coating layer comprising at least one of a metal nitride, a metal oxide, or a metal carbide; and   a plurality of flexible leaflets supported by the metal frame to form a one-way valve for blood flow therethrough.   
     
     
         2 . The prosthetic heart valve of  claim 1 , wherein the metal frame comprises a radially collapsible and radially expandable stent or an undulating wireform. 
     
     
         3 . The prosthetic heart valve of  claim 1 , wherein the metal frame comprises at least one of stainless steel, cobalt-chromium, titanium alloy, nitinol, a metal alloy, a shape-memory metal, or a super-elastic metal. 
     
     
         4 . The prosthetic heart valve of  claim 1 , wherein the at least one elemental metal of the bond layer includes at least one of ruthenium, palladium, silver, iridium, platinum, and gold. 
     
     
         5 . The prosthetic heart valve of  claim 1 , wherein the coating layer has a thickness of about 10 μm or less. 
     
     
         6 . The prosthetic heart valve of  claim 1 , wherein the coating layer has a grain size of about 20 nm or less. 
     
     
         7 . The prosthetic heart valve of  claim 1 , wherein the coating layer includes both cubic and orthorhombic phases. 
     
     
         8 . The prosthetic heart valve of  claim 1 , wherein the coating layer is polycrystalline with randomly oriented grains. 
     
     
         9 . The prosthetic heart valve of  claim 1 , wherein the at least one of the metal oxide, the metal nitride, or the metal carbide of the coating layer comprises at least one metal selected from the group consisting of aluminum, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, ruthenium, cobalt, rhenium, iridium, palladium, and platinum. 
     
     
         10 . The prosthetic heart valve of  claim 1 , wherein the bond layer comprises chromium and the coating layer comprises chromium nitride. 
     
     
         11 . A prosthetic heart valve comprising:
 a metal frame;   a bond layer disposed over at least a portion of the metal frame, the bond layer including one or more stable and non-reactive elemental noble metals;   a coating layer disposed over at least a portion of the bond layer; and   a plurality of flexible leaflets supported by the metal frame to form a one-way valve for blood flow therethrough.   
     
     
         12 . The prosthetic heart valve of  claim 11 , wherein the metal frame comprises a radially collapsible and radially expandable stent or an undulating wireform. 
     
     
         13 . The prosthetic heart valve of  claim 11 , wherein the metal frame comprises at least one of stainless steel, cobalt-chromium, titanium alloy, nitinol, a metal alloy, a shape-memory metal, or a super-elastic metal. 
     
     
         14 . The prosthetic heart valve of  claim 11 , wherein the one or more stable and non-reactive elemental noble metals of the bond layer include at least one of aluminum, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, ruthenium, cobalt, rhenium, iridium, palladium, platinum, copper, silver, and gold. 
     
     
         15 . The prosthetic heart valve of  claim 11 , wherein the bond layer comprises chromium and the coating layer comprises chromium nitride. 
     
     
         16 . The prosthetic heart valve of  claim 11 , wherein the coating layer comprises at least one of a metal nitride, a metal oxide, or a metal carbide. 
     
     
         17 . The prosthetic heart valve of  claim 11 , wherein the coating layer has a thickness of about 10 μm or less. 
     
     
         18 . The prosthetic heart valve of  claim 11 , wherein the coating layer has a grain size of about 20 nm or less. 
     
     
         19 . The prosthetic heart valve of  claim 11 , wherein the coating layer includes both cubic and orthorhombic phases. 
     
     
         20 . The prosthetic heart valve of  claim 11 , wherein the coating layer is polycrystalline with randomly oriented grains.