I doubt it.
Most of those cords are rated for temperatures 70C - 85C, and you'd be very hard pressed to get that kind of temperature on the outside of a heatsink or back of a graphics card. Keep in mind, the hottest spot would likely be the GPU, which can go above 100C depending on your model... but it drops drastically to where the cord would be.
Just to be safe try to get them off the video card, but you should be fine.