A prosthetic heart valve, comprising: a stent or frame (12, 102, 302, 3402, 3502, 4502, 4602) extending in a longitudinal direction between an inflow end and an outflow end; a cuff (106, 306, 3406, 3506, 4506) coupled to a luminal surface of the stent; and a plurality of prosthetic leaflets (108, 2300, 2808, 2908, 3008, 3108, 3208, 3308, 3408, 3508, 3708, 3808, 3908, 4008, 4108, 4208, 4308, 4408, 4508) coupled to at least one of the cuff and the stent and having an open condition and a closed condition, the plurality of prosthetic leaflets adapted to allow blood to flow from the inflow end toward the outflow end when in the open condition and to retard blood from flowing from the outflow end toward the inflow end when in the closed condition, each of the plurality of leaflets being formed of a fabric (404, 2104, 2204, 2304, 2404a, 2404b, 2840, 2940, 3040, 3140, 3240, 3255, 3340, 3355, 3440, 3540, 3640, 3740, 3840, 3940, 4040, 4140, 4240, 4340, 4440, 4540) and having a first major surface (2815, 3415, 3615, 3715, 3815, 4015, 4115, 4315, 4515) opposite a second major surface (2820, 2920, 3420, 3520, 3620, 3720, 3820, 4120, 4220, 4520), the first major surface generally facing the outflow end of the stent in the closed condition, the second major surface generally facing the inflow end of the stent in the closed condition, wherein the fabric has a first group of fibers (390, 600) extending in a first direction of the fabric and a second group of fibers (390, 600) extending in a second direction of the fabric different than the first direction, the first group of fibers and the second group of fibers being interlaced in an ordered arrangement, the first group of fibers and the second group of fibers both being composed of ultra-high molecular weight polyethylene, UHMWPE, at least one layer of the fabric having a thread count of between about 118 and about 197 fibers by between about 39 and about 118 fibers per square centimeter (about 300 and about 500 fibers by between about 100 and about 300 fibers per square inch), the fabric having a thickness of between about 50 μm and about 100 μm, characterized by a polymer coating (402, 2102, 2103, 2202, 2302, 2402, 2945, 3045, 3050, 3145, 3150, 3151, 3152, 3245, 3345, 3350, 3360, 3450, 3545, 3645, 3650, 3745, 3750, 3751, 3850, 3950, 4050, 4150, 4151, 4152, 4245, 4350, 4545) formed of UHMWPE on at least one of the first major surface or the second major surface. a stent or frame (12, 102, 302, 3402, 3502, 4502, 4602) extending in a longitudinal direction between an inflow end and an outflow end; a cuff (106, 306, 3406, 3506, 4506) coupled to a luminal surface of the stent; and a plurality of prosthetic leaflets (108, 2300, 2808, 2908, 3008, 3108, 3208, 3308, 3408, 3508, 3708, 3808, 3908, 4008, 4108, 4208, 4308, 4408, 4508) coupled to at least one of the cuff and the stent and having an open condition and a closed condition, the plurality of prosthetic leaflets adapted to allow blood to flow from the inflow end toward the outflow end when in the open condition and to retard blood from flowing from the outflow end toward the inflow end when in the closed condition, each of the plurality of leaflets being formed of a fabric (404, 2104, 2204, 2304, 2404a, 2404b, 2840, 2940, 3040, 3140, 3240, 3255, 3340, 3355, 3440, 3540, 3640, 3740, 3840, 3940, 4040, 4140, 4240, 4340, 4440, 4540) and having a first major surface (2815, 3415, 3615, 3715, 3815, 4015, 4115, 4315, 4515) opposite a second major surface (2820, 2920, 3420, 3520, 3620, 3720, 3820, 4120, 4220, 4520), the first major surface generally facing the outflow end of the stent in the closed condition, the second major surface generally facing the inflow end of the stent in the closed condition, wherein the fabric has a first group of fibers (390, 600) extending in a first direction of the fabric and a second group of fibers (390, 600) extending in a second direction of the fabric different than the first direction, the first group of fibers and the second group of fibers being interlaced in an ordered arrangement, the first group of fibers and the second group of fibers both being composed of ultra-high molecular weight polyethylene, UHMWPE, at least one layer of the fabric having a thread count of between about 118 and about 197 fibers by between about 39 and about 118 fibers per square centimeter (about 300 and about 500 fibers by between about 100 and about 300 fibers per square inch), the fabric having a thickness of between about 50 μm and about 100 μm, characterized by a polymer coating (402, 2102, 2103, 2202, 2302, 2402, 2945, 3045, 3050, 3145, 3150, 3151, 3152, 3245, 3345, 3350, 3360, 3450, 3545, 3645, 3650, 3745, 3750, 3751, 3850, 3950, 4050, 4150, 4151, 4152, 4245, 4350, 4545) formed of UHMWPE on at least one of the first major surface or the second major surface.